Background and Objectives: The vaccine against human papilloma virus (HPV) infection is recommended, according to the Serbian National Immunization Program, for children and adolescents aged 9–19 years. Three doses are given keeping in mind the recommendation that the second dose should be administered at least one month after the first dose, and the third at least three months after the second dose. No children who participated in this first study received the third dose because they did not meet these criteria. The study explored parents’ knowledge about HPV infection and their awareness of the HPV vaccine. Materials and Methods: A cross-sectional questionnaire-based study was carried out in the city of Nis, in southeastern Serbia. According to the 2011 population census, the sample of children aged 9 to 19 was 850, and during the observed period, 631 children received the vaccine. A total of 615 fully completed questionnaires filled out by parents were included in the study. The study was carried out from 6 June 2022 to 7 October 2022. Multivariable logistic regression analysis was used. The odds ratio (OR) and 95% confidence intervals (CI) were calculated. The statistical significance was p < 0.05. Results: A total of 615 children were included in the study (499 were vaccinated with the first dose and 116 with the second). Out of 499 children vaccinated with the first dose, 398 (79.6%) were girls, which is significantly higher than the rate for boys (101). The independent variable sex was statistically significant at the level of p = 0.84, OR = 2.664 (95% CI from 0.879 to 7.954). Boys are 164% less likely to be vaccinated with the HPV vaccine than girls. We determined that the independent variable place of residence was significant at the level of p = 0.041, . Based on these findings, we determined that parents who came from rural areas were 82% less likely to know about HPV infection and HPV vaccination. Children under 15 years of age were significantly more vaccinated than those ≥15 years . The independent variable parental education was significant at the level of OR = 0.494, 95% CI from 0.301 to 0.791. Parents who had medical education showed significantly higher awareness about the infection caused by HPV and about the HPV vaccine (p = 0.004) than parents with no medical education. The possibility that a parent would decide to vaccinate a child significantly increased upon a pediatrician’s recommendation, p = 0.000 with OR = 0.250 (95% CI from 0.127 to 0.707). Health insurance coverage of HPV vaccination for children aged 9–19 years significantly increased the probability of a positive parental decision to vaccinate a child, p = 0.001 with OR = 3.034 (95% CI from 1.063 to 8.662). Conclusion: We identified several significant factors that were important for HPV vaccination such as: children under 15 years, female sex, urban place of residence, medical education of parents, pediatrician’s recommendation of the HPV vaccination, and HPV vaccination free of charge. Health education and the promotion of HPV vaccination as well as healthy sexual behavior are important factors in the preservation and improvement of the health of the whole population. The most common viral infection, which is predominantly sexually transmitted, is caused by human papillomavirus (HPV) . This inChronic HPV infection, together with other risk factors for cervical cancer, plays an important role in the development of this cancer as well. The most significant risk factors are smoking, immunodeficiency, long-term use of oral contraceptives, promiscuous behavior, and having more than two pregnancies. Other risk factors include a family history of cervical cancer and other descriptive characteristics, obesity, and poor diet ,9,10,11.There are more than 207 HPV genotypes  among whAn HPV vaccine was established in order to enable the primary prevention of HPV infection and cervical cancer. Three HPV vaccines exist today: the bivalent (2vHPV) vaccine for girls licensed in 2006, the quadrivalent (4vHPV) HPV vaccine for boys licensed in 2009, and the 9-valent HPV vaccine (9vHPV) licensed for both girls and boys in 2014. The most common World Health Organization (WHO) recommendations regarding routine vaccination are related to children age 9–14 because the HPV vaccine is the most effective if it received before recipients become sexually active, i.e., before they are exposed to HPV infection . The vacIn 2007, Australia became one of the first countries to introduce the HPV vaccine ,23, and The three HPV vaccines do not provide complete protection against all oncogenic HPV types, and immunity is not lifelong . That isOrganized cervical cancer screening has been conducted in the Republic of Serbia since 2012. The screening is mandatory for women aged 25 to 69 . AccordiIn the Republic of Serbia, vaccination against HPV infection is not part of the mandatory national immunization program. It is recommended for children aged 9, before the first sexual intercourse, and primarily for children in the seventh grade of primary school age 13) . HPV vac . HPV vaWe conducted a cross-sectional study involving the parents of children aged 9–19 years. The period of observation lasted from 6 June 2022 to 7 October 2022. The study took place at the primary clinic at the Healthcare Center Nis at the Counseling Center for Healthy School Children. The Healthcare Center Nis is the largest health care institution of its kind in the Republic of Serbia. The city of Nis is the largest city in southeastern Serbia. An anonymous questionnaire was distributed only to parents of children who came for vaccination. If the parent was not present, which was often the case with children aged ≥ 15, the child did not fill out the questionnaire. Some of the children this age were accompanied by parents because the HPV vaccine is being widely administered for the first time this year, and the children only signed the consent form, which they are legally allowed to do .Since the beginning of 2022, the promotion of vaccination against HPV infection among parents has been carried out at the counseling center. Certain pediatricians from the Nis health center and an immunization coordinator/epidemiologist from the Nis Institute for Public Health went to Belgrade , where they received basic instructions about the vaccine and were also trained on how to encourage parents and other pediatricians. The results of good preparation were reflected in a great number of parents who brought their children for vaccination in June as well as in unreserved support from all pediatricians for giving this vaccine to as many children as possible. The state helped by introducing significant relief by making vaccination free for children aged 9–19 years. According to the 2011 population census, the sample of children aged 9 to 19 was 850. In the observed period, 631 children received the vaccine. This study included 615 fully completed questionnaires, which were filled out by parents, and incomplete questionnaires were excluded.Before vaccine administration, a visit to the pediatrician at the Counseling Center for Healthy School Children was mandatory as well as signing the consent form. According to expert methodological instructions for the application of Gardasil 9 vaccine in Serbia, consent for children up to 15 years of age had to be signed by parents or guardians. Children over 15 years of age could sign their own consent for vaccination with Gardasil 9 . Inclusion criteria were: children born between 2003 and 2013 and signed consent for the vaccination. Exclusion criteria were younger or older children and no signed consent.Approval by the Ethics Committee of the Public Healthcare Center Nis was not necessary because according to the Serbian National Immunization Laws, signature or written consent of the parent or of the adolescent (if they are aged 15 years or above) is mandatory for the application of each recommended vaccine . The questionnaires were administered to parents at the Counseling Center for Healthy School Children. Participation in the study was voluntary. Signed consent forms were obtained from all participants. The parents filled out the short questionnaire during a visit to the pediatrician for the child’s vaccination.Data were collected using a short semi-structured questionnaire that consisted of two sections .Section one: The first section explored participations’ sociodemographic characteristics, including sex, age, education, place of residence, and pediatrician recommendation. It consisted of 5 items .Section two: The second section consisted of 15 items divided into three subsections . Knowledge was evaluated with a composite score estimated using a total of 13 items regarding risk and protective factors, preventive measures, and the outcome of HPV infection. Participants had three possible options regarding the proposed factors and correct answers were coded with two points. As for the rest of the questions, the given options were yes, no, and I do not know and correct answers were given two points. The total number of points represented the participants’ HPV infection knowledge score (KS), with higher scores meaning better knowledge. The maximum number of points was 30. The results of all answers are shown in The 9vHPV vaccination in Serbia is recommended for children aged nine and up, before the first sexual intercourse, and primarily for children in the seventh grade of primary school (13 years of age). Active immunization against HPV infection is carried out with the required number of doses (two or three), which is recommended by the WHO depending on the type of vaccine and age . Three dp-value was set at p < 0.05.An Excel database was created for all collected data. Data are presented as the mean and standard deviation (SD) or as frequencies and proportions. Percentages were used to describe the demographic status and the frequency of parents’ responses to the questions in the questionnaire. All analyses were performed using SPSS software version 22.0. Multivariate analysis was used to determine the factors that had an impact on the parents’ decision to vaccinate a child. The Out of the 615 children, 499 received the first dose of HPV vaccine, and 116 received the second dose. Out of the original 499 children (398 girls and 101 boys), there were significantly more girls, 79.6%, than boys. That is, there were 3.9 times more vaccinated girls than boys on average. p < 0.001). The total number of children aged 9–14 years who were vaccinated with the first dose of HPV vaccine was 280 (56.1%). In the age group 15–19, there were 219 children (43.9%) who received the first dose of the HPV vaccine . Boys are 164% less likely to be vaccinated with HPV vaccine than girls. The independent variable sex was statistically significant at the level of p = 0.041, OR = 3.809, (95% CI from 1.702 to 8.525). Based on these findings, we determined that parents who came from rural areas were 82% less likely to know about HPV infection and HPV vaccination. Children under 15 years of age were significantly more vaccinated than those ≥ 15 years, OR = 3.698 (95% CI from 1.354 to 12.598). The independent variable parental education was significant, OR = 0.494 (95% CI from 0.301 to 0.791). Parents who had medical education showed significantly higher awareness about the infection caused by HPV and about the HPV vaccine (p = 0.004), OR = 0.494 (95% CI from 0.301 to 0.791) than non-medically educated parents. A pediatrician’s recommendation had a significant effect on the vaccination rate, OR = 0.250 (95% CI from 0.127 to 0.707). Health insurance coverage of HPV vaccination for children aged 9–19 years significantly increased the probability of a positive parental decision to vaccinate a child, p = 0.001 with OR = 3.034 (95% CI from 1.063 to 8.662) (We determined that the independent variable place of residence was significant at the level of o 8.662) .This is the first organized immunization of children aged 9–19 with the 9-valent HPV vaccine in Serbia. Our cross-sectional questionnaire-based study was conducted with the aim of exploring parents’ knowledge about HPV infection and their awareness of the HPV vaccine. According to the Serbian National Immunization Program, the HPV vaccine is recommended for children and adolescents aged 9–19 years, and for this age group, it is free of charge. In addition to the unexpectedly high response to vaccination against HPV infection, we identified several significant factors that were important for positive parental decisions to vaccinate children with the HPV vaccine: children under age 15, female sex of children, urban residence, medical education of parents, pediatrician recommendation of the HPV vaccination, and health insurance coverage of HPV vaccination.In general, parents showed good knowledge about HPV infection and the HPV vaccine, which was expected because the majority of parents had medical education. However, we also observed a lack of parental knowledge about whether HPV infection always leads to clinical manifestation of the disease and about who was at higher risk of HPV infection. In terms of knowledge about the HPV vaccine, the questions with the fewest correct answers were those regarding the number of doses, the duration of immunity, and the most common side effects. The results of our study are in agreement with similar studies conducted in Europe and the rest of the world ,31,32,33The most common concerns indicated by parents in our study were related to vaccine safety, side effects of the vaccine, and lifelong protection after vaccination. Our results are in accordance with similar studies. Parents in other studies worried more about post-vaccination sexual promiscuity, moral problems related to sexuality, and conservative and religious views, and there was denial that children are at risk ,34,35.Our results showed that there were nearly four times more vaccinated girls than boys. This difference in our study is greater than in the literature, where the difference is mostly twofold. Results of meta-analyses showed that there were two times more vaccinated girls than boys ,37. The In our results, there were nearly 3 times more vaccinated children aged 9–14 than adolescents aged ≥15 years, particularly among boys. Parents of children aged 15 years and over were not very well informed about HPV infection and the HPV vaccine. Our findings are in agreement with the findings of other similar studies . ResultsThere are different findings in the available literature. In a systematic meta-analysis by Holman et al., the authors stated that the age of a child was a common reason for refusing or delaying HPV vaccination, and older girls were more likely to be vaccinated than younger girls. In only two studies did age not predict any intention of parents to vaccinate their children ,35.The state of parental knowledge has an essential influence on the immunization of children . Newman As vaccination progressed in the city of Nis, more parents heard about it but when vaccination began, some parents with children under 15 years of age were away on vacation. Children over 15 were still going to school (high school vacation started on 24 June 2022) and that is why there was initially a greater response from parents with children over 15.Compared with our study, the literature contains fewer recorded vaccination differences among girls and boys. The results of studies showed that there were two times more vaccinated girls than boys ,32. The In undeveloped regions such as Nigeria and Kenya ,37 and iThe findings of 62 studies showed that a significant predictor of successful HPV vaccination was physician’s recommendation (r = 0.46 (95% CI from 0.34 to 0.56)). It had the highest impact on parents’ positive decision, followed by worry about HPV vaccine safety (r = −0.31 (95% CI from −0.41 to −0.16)), preventive examination of children during one year (r = 0.22 (95% CI from 0.11 to 0.33)), and parents’ health beliefs towards vaccines (r = 0.19 (95% CI from 0.08 to 0.29) .In Serbia, the HPV vaccine is expensive, and the government’s approval at the beginning of this year to cover the HPV vaccination for children aged 9–19 with health insurance was important for the success of the vaccination effort. In our results, both pediatrician recommendation and health insurance coverage of HPV vaccination were independently associated with positive decision of parents towards the vaccine. Some studies have shown that a pediatrician recommendation was the most significant predictor of HPV vaccination ,10,17. AWe here presented the results of the first organized vaccination of children and adolescents against HPV infection, and we also showed the results of the first research on parental knowledge about HPV infection and HPV vaccine in southeastern Serbia. Significant factors for positive parental decisions about HPV vaccination for their children were children under 15 years, female children, urban residence, parents’ medical education, pediatrician recommendation of vaccination, and free vaccination. The vaccination of boys aged 15 years and over was significantly lower compared with girls from the same age group. In accordance with the results of our study, when it comes to the decision to get the HPV vaccine, personal contact with a pediatrician could be very useful both for parents and children, especially for boys. In order to preserve and improve the health of the whole population as well as of groups of individuals at higher risk, the promotion of HPV vaccination, health education measures, the promotion of healthy sexual behavior, and the support of the government are also important.This study presented the first results of the organized immunization of children aged 9–19 years with the recommended HPV vaccine. Our findings indicated what factors are associated with positive parental decisions to pursue HPV vaccination for their children. We noted extremely high interest among parents for the first dose of HPV vaccine, and no side effects were reported. This study was created as a longitudinal study, and all vaccinated children and adolescents will be followed up for a minimum of 10 years after the vaccination.We could not include all the parents we wanted in the survey.


Randomized controlled trials (RCTs) and cohort studies are the most common study design types used to assess treatment effects of medical interventions. We aimed to hypothetically pool bodies of evidence (BoE) from RCTs with matched BoE from cohort studies included in the same systematic review.BoE derived from systematic reviews of RCTs and cohort studies published in the 13 medical journals with the highest impact factor were considered. We re-analyzed effect estimates of the included systematic reviews by pooling BoE from RCTs with BoE from cohort studies using random and common effects models. We evaluated statistical heterogeneity, 95% prediction intervals, weight of BoE from RCTs to the pooled estimate, and whether integration of BoE from cohort studies modified the conclusion from BoE of RCTs.I2 was 48%, and the median contributed percentage weight of RCTs to the pooled estimates was 40%. The direction of effect between BoE from RCTs and pooled effect estimates was mainly concordant (79.7%). The integration of BoE from cohort studies modified the conclusion (by examining the 95% CI) from BoE of RCTs in 32 (27%) of the 118 BoE-pairs, but the direction of effect was mainly concordant (88%).Overall, 118 BoE-pairs based on 653 RCTs and 804 cohort studies were pooled. By pooling BoE from RCTs and cohort studies with a random effects model, for 61 (51.7%) out of 118 BoE-pairs, the 95% confidence interval (CI) excludes no effect. By pooling BoE from RCTs and cohort studies, the median Our findings provide insights for the potential impact of pooling both BoE in systematic reviews. In medical research, it is often important to rely on both evidence of RCTs and cohort studies to get a whole picture of an investigated intervention-disease association. A decision for or against pooling different study designs should also always take into account, for example, PI/ECO similarity, risk of bias, coherence of effect estimates, and also the trustworthiness of the evidence. Overall, there is a need for more research on the influence of those issues on potential pooling.The online version contains supplementary material available at 10.1186/s12916-022-02559-y. Randomized controlled trials (RCTs) and cohort studies are the most common study designs used to assess treatment effects of medical interventions , 2. RCTsHowever, RCTs may not be available for certain medical treatments due to ethical reasons or may suffer from inherent methodological limitations such as low external validity . On the According to recent GRADE guidance, cohort studies can be highly valuable and provide complementary, sequential, or replacement evidence for RCTs in a systematic review or other evidence syntheses . HoweverTo close this important research gap, this empirical study aims to conduct a pooling scenario of bodies of evidence (BoE) from RCTs with matched BoE from cohort studies. We investigate the extent of how the integration of BoE from cohort studies modifies the conclusion of BoE of RCTs, the direction of effect estimates derived from BoE of RCTs, and its impact on statistical heterogeneity. Moreover, we will evaluate the contributed aggregated weights of RCTs to the pooled estimates, use random effects and common effects models for pooling, calculate 95% prediction intervals (PIs), and test for subgroup differences between BoE from RCTs and cohort studies.The sample of this empirical study was based on a large meta-epidemiological study , which wThe original search for the meta-epidemiological study was conducted in MEDLINE on 04.05.2020 for the period between 01.01.2010 and 31.12.2019 in the 13 medical journals with the highest impact factor . Initially, we planned to include the ten highest impact factor journals, but three journals did not publish any systematic review with an eligible BoE-pair. We therefore included the subsequent three journals according to the JCR 2018. The search strategy including the list of considered journals is given in Additional file For each included BoE from a systematic review, we included a maximum of three patient-relevant outcomes  and a maximum of three intermediate disease markers . If more than three outcomes were available for a given systematic review, we included the primary outcomes and thereafter we used a top-down approach (mentioned first). We evaluated the similarity of the PI/ECO criteria between BoE-pair from RCTs and cohort studies within each systematic review. For each BoE-pair, the similarity of each PI/ECO domain was rated as “more or less identical,” “similar but not identical,” or “broadly similar”  extracted the following data for each included BoE-pair into a piloted data extraction sheet: name of the first author, year of publication, type of intervention/exposure , description of the comparator, effect estimates , and number of studies. A detailed description of data extraction can be found elsewhere . For theFor our pooling scenario, we re-analyzed the effect estimates of all eligible systematic reviews in a two-step approach: For each identified BoE-pair, we first pooled the effect estimates obtained from RCTs and cohort studies separately using a random effects model. Primary studies based on inappropriate study designs  were excluded.Second, we pooled the BoE from RCTs with the BoE from cohort studies with a random effects model for each BoE-pair. Binary outcomes  and continuous outcomes  were considered for analysis. Random effects models were used to account for potential between-study heterogeneity. For the sensitivity analysis, we used a common effects model to evaluate whether this hypothetical scenario is more conservative for pooling BoE from RCTs and cohort studies.p-value < 0.05 was considered as statistical significant.To explore the impact of including cohort studies on pooled effect estimates by combining BoE from RCTs and cohort studies (with or without subgroups), we compared the results and conclusions (95% CI including vs. excluding the null effect) between the BoE of RCTs only and that including both RCTs and cohort studies. Then, we evaluated the contributed weight of RCTs to the pooled estimates and conducted a statistical test for subgroup differences between the two types of BoE. A In an additional analysis, we used effect estimates of cohort studies as a reference and compared the results and conclusion between the BoE of cohort studies only and that including both, RCTs and cohort studies.χ2 test. We quantified any inconsistency by using the I2 parameter: I2=((Q−df))/Q × 100%, where Q is the χ2 statistic and df is its degrees of freedom [I2-value of greater than 50% was considered to represent considerable heterogeneity [τ2, which is independent of study size and describes variability between studies in relation to the risk estimates [τ2 due to the use of different scales between meta-analyses  version 5.3 [Heterogeneity in meta-analyses was tested with a standard  freedom . An I2-vstimates . For consion 5.3 .Whereas in a random effects meta-analysis, the focus is usually on the average treatment effect and its 95% CI, the calculation of a prediction interval (95% PI) also considers the potential treatment effect within an individual study setting, as this may differ from the average effect . 95% PIsOverall, 64 systematic reviews of RCTs and cohort studies were included –76. Of tOur sample of 118 BoE-pairs was based on 653 RCTs and 804 cohort studies. Detailed study characteristics including a description of the population, intervention/comparator, outcomes, range of study length, and risk of bias/study quality of primary studies included for each outcome pair have been described elsewhere .I2 was 5% (τ2=0) across BoE from RCTs and 41% (τ2=0.03) across BoE from cohort studies, whereas the mean I2 was 23% (τ2=0.14) and 42% (τ2=0.18), respectively. Table Two of the outcome pairs were classified (PI/ECO similarity degree) as “more or less identical” and 82 as “similar but not identical,” whereas 34 were classified as “broadly similar.” Out of the 118 BoE from RCTs, for 39 (33.1%), the 95% CI excludes no effect, whereas for the BoE for cohort studies, 58 (49.2%) indicated a 95% CI excluding no effect. Twenty-four (20.3%) out of 118 BoE-pairs showed simultaneously for BoE from RCTs and BoE from cohort studies a 95% CI excluding no effect and a concordant direction of effect. The median p<0.05) for 25 BoE-pairs (21.2%). By pooling BoE from RCTs and cohort studies, the median I2 was 51% (τ2=0.05), whereas the mean I2 was 45% (τ2=0.11). The contributed weight of RCTs to the pooled estimates was 40% (median) and 42% (mean). As for the 95% PIs, 21.2% (n=25) of the pooled BoE from RCTs and cohort studies excluded no effect.By pooling BoE from RCTs and cohort studies with a random effects model, for 61 (51.7%) out of 118 BoE-pairs, the 95% CI excludes no effect. For the common effects model, for 77 (62.3%) out of 118 BoE-pairs, the 95% CI excludes no effect. Approximately half of the binary effect sizes were in the range of 0.75 to 1.25, and 64.2% reported an effect estimate <1. The test for subgroup difference comparing BoE from RCTs and BoE of cohort studies was statistically significant (n=5) and >0.50 for 3.4% (n=4) for the dichotomous effect measures. The integration of BoE from cohort studies modified the conclusion from BoE of RCTs in 32 (27.1%) of the 118 BoE-pairs ; in 28 (87.5%) of these 32 BoE, the direction of effect was concordant. In nine (28.1%) of these 32 BoE-pairs, the test of subgroup difference was statistically significant (p<0.05) comparing BoE from RCTs and BoE from cohort studies . In 12 (37.5 %) of these 32 BoE-pairs, the overall degree of PI/ECO similarity was judged as “broadly similar.” Populations , interventions , and comparators  rated as “broadly similar” accounted for PI/ECO dissimilarities overall. In 20 (62.5%) of the 32 BoE-pairs, the degree of PI/ECO similarity was judged as “similar but not identical.” Populations , interventions , comparators , and outcomes  rated as “similar but not identical” accounted for PI/ECO dissimilarities.The direction of effect between BoE from RCTs and pooled effect estimates was mainly concordant in 94 of 118 BoE-pairs (79.7%). The difference between effect estimates was >0.25 for 4.2%  and higher across meta-analyses of cohort studies  compared to meta-analyses of RCTs . The integration of BoE from cohort studies modified the conclusion derived from BoE of RCTs in nearly 30% of the BoE-pairs. The direction of effect between BoE of RCTs and pooled estimates, however, was mainly concordant. This suggests that by adding evidence from cohort studies statistical precision increased substantially.This meta-epidemiological study is the first empirical study in medical research that evaluates the impact scenario of pooling bodies of evidence from RCTs and cohort studies. Overall, 118 BoE-pairs based on 653 RCTs and 804 cohort studies were included. By pooling BoE from RCTs and cohort studies in about 50% of the BoE-pairs, the 95% CI excludes no effect, whereas in about one-third of the included BoE from RCTs, the 95% CI excludes no effect. For 21% of pooled estimates, the test for subgroup difference comparing BoE from RCTs and BoE of cohort studies was statistically significant. The median weights of BoE from RCTs to the pooled estimates were 40%, suggesting that on average the contribution weight was not dissimilar between both BoE. Overall, the degree of statistical heterogeneity was moderate  compared to RCTs . This finding is in line with our study. However, in our study, the integration of BoE from cohort studies modified the conclusion from BoE of RCTs less often (27% vs. 44%) [We did not identify any similar empirical study using a pooling scenario of different study designs in the field of medical research. However, a recent methodological study investigated a similar pooling scenario in nutrition research . This lavs. 44%) . Two maivs. 44%) . A recenvs. 44%) . Second,vs. 44%) .A recent meta-research study investigated how RCTs and observational studies were combined in meta-analyses . In nearIn a survey investigating the rationale, perceptions, and preferences for the integration of RCTs and observational studies in evidence syntheses by Cuello-Garcia and colleagues , it was According to the recent GRADE guidance on optimizing the integration of RCT and observational studies in evidence syntheses, observational studies can provide valuable information as complementary, sequential, or replacement evidence for RCTs . In our Cochrane Handbook indicated that authors should expect greater statistical heterogeneity in a systematic review of observational studies compared to a systematic review of RCTs. Reasons include diverse ways in which observational studies may be designed to investigate the effects of interventions/exposures, and partly due to the increased potential for methodological variation between primary studies and the resulting variation in their risk of bias. Therefore, the Cochrane Handbook recommends that RCTs and observational studies should not be combined in a meta-analysis . In conincrease . Moreoveincrease . Finallyincrease , 36, 56.Overall, it looks like further methodological research is needed to shed light into this gray area. On the one hand, further research should address the application of existing guidance in terms of utility, acceptability, and reproducibility and elaborate ways to deal with occurring challenges . On the We assume that methodological trial characteristics are other possible drivers towards disagreement, since observational studies are prone to risk of bias by confounding , and appThis paper did not aim to provide insights on how pooling results from different study designs impacts the certainty rating of results and whether it reduces or increases the amount of low or very low certainty of evidence ratings. In a recently published hypothetical scenario analysis, we could show that pooling BoE from RCTs and cohort studies for nutrition-related research questions would reduce the amount of very low and low certainty of evidence ratings . We recon=118), which was based on 653 RCTs and 804 cohort studies. Second, we selected BoE-pairs from systematic reviews published in high-impact medical journals, which have shown to be of higher methodological quality [This study has several strengths. First, we analyzed a large sample of BoE-pairs  effect estimates and re-calculated effect estimates. Table S4. Reason for exclusion from the pooling scenario. Table S5. Pooling results. Figures S1-S118. Fig S1. Forest plot: Low sodium (Intervention/Exposure); All-cause mortality (Outcome). Fig. S2. Forest plot: Low sodium; Cardiovascular disease. Fig. S3. Forest plot: Intra-aortic balloon pump; All-cause mortality. Fig. S4. Forest plot: Self-administered therapy; Treatment success. Fig S5. Forest plot: Self-administered therapy; Treatment completion. Fig. S6. Forest plot: Self-administered therapy; All-cause mortality. Fig S7. Forest plot: Antiretroviral therapy; HIV infection. FigS8-Forest plot: Nonnutritive sweeteners; Body Mass Index random sequence. Fig. S9. Forest plot: Surgical abortion by mid-level providers; Failure or incomplete abortion. Fig. S10. Forest plot: Surgical abortion by mid-level providers; Complications. Fig. S11. Forest plot: Surgical abortion by mid-level providers; Abortion failure and complications. Fig. S12. Forest plot: Clopidogrel pretreatment for percutaneous coronary intervention; All-cause mortality. Fig. S13. Forest plot: Clopidogrel pretreatment for percutaneous coronary intervention; Major bleeding. Fig. S14. Forest plot: Clopidogrel pretreatment for percutaneous coronary intervention; Coronary heart disease. Fig. S15. Forest plot: P2Y12 inhibitor pretreatment in non-ST elevation acute coronary syndrome; All-cause mortality. Fig. S16. Forest plot: P2Y12 inhibitor pretreatment in non-ST elevation acute coronary syndrome; Major bleeding. Fig. S17. Forest plot: P2Y12 inhibitor pretreatment in non-ST elevation acute coronary syndrome; Main composite ischemic endpoint. Fig. S18. Forest plot: Mediterranean diet; Breast cancer. Fig. S19. Forest plot: High calcium; All fractures. Fig. S20. Forest plot: High calcium; Verterbral fractures. Fig. S21. Forest plot: High calcium; Hip fracture. Fig. S22. Forest plot: Sigmoidoscopy; Colorectal cancer mortality. Fig. S23. Forest plot: Sigmoidoscopy; Colorectal cancer incidence. Fig. S24. Forest plot: High omega-3; Cerebrovascular disease. Fig. S25. Forest plot: High α-linolenic acid; Coronary heart disease. Fig. S26. Forest plot: High omega-3; Coronary heart disease. Fig. S27. Forest plot: Omega-6; Coronary heart disease. Fig. S28. Forest plot: High calcium; Cardiovascular mortality. Fig. S29. Forest plot: High dairy; Systolic blood pressure. Fig. S30. Forest plot: Radiation therapy; Erectile dysfunction. Fig. S31. Forest plot: Radical prostatectomy; Urinary incontinence. Fig. S32. Forest plot: Radical Prostatectomy; Erectile dysfunction. Fig. S33. Forest plot: Disease-modifying drugs; Conversion to clinically definite multiple sclerosis. Fig. S34. Forest plot: Extracranial-intracranial arterial bypass; All-cause mortality. Fig. S35. Forest plot: Extracranial-intracranial arterial bypass; Stroke. Fig. S36. Forest plot: Extracranial-intracranial arterial bypass; Stroke mortality or dependency. Fig. S37. Forest plot: Transcatheter aortic valve implantation; Early all-cause mortality. Fig. S38. Forest plot: Transcatheter aortic valve implantation; Mid-term all-cause mortality. Fig. S39. Forest plot: Transcatheter aortic valve implantation; Long-term all-cause mortality. Fig. S40. Forest plot: Treating gestational diabetes mellitus; High birth weight. Fig. S41. Forest plot: Treating gestational diabetes mellitus; Large-for-gestational age neonate. Fig. S42. Forest plot: Treating gestational diabetes mellitus; Shoulder dystocia. Fig. S43. Forest plot: Treating asymptomatic bacteriuria; Pyelonephritis. Fig. S44. Forest plot: Bacillus Calmette-Guérin vaccination; All-cause mortality. Fig. S45. Forest plot: Measles containing vaccines; All-cause mortality. Fig. S46. Forest plot: Total hip arthroplasty; Reoperation. Fig. S47. Forest plot: Total hip arthroplasty; Dislocation. Fig. S48. Forest plot: Total hip arthroplasty; Deep infection. Fig. S49. Forest plot: Chest-compression-only cardiopulmonary resuscitation; Survival. Fig. S50. Forest plot: Non-calcium-based phosphat binders; All-cause mortality. Fig. S51. Forest plot: Parenteral influenza vaccine; Influenza-like illness. Fig. S52. Forest plot: Parenteral influenza vaccine Influenza. FigS53-Forest plot: Inactivated influenza vaccines; Influenza. Fig. S54. Forest plot: Inactivated influenza vaccines; Influenza-like illness. Fig. S55. Forest plot: High total flavonoids; Colorectal neoplasms. Fig. S56. Forest plot: Transfusion; All-cause mortality. Fig. S57. Forest plot: Caesarean section; Urinary incontinence. Fig. S58. Forest plot: Caesarean section; Fecal incontinence. Fig. S59. Forest plot: Antiretroviral therapy by nurses; All-cause mortality. Fig. S60. Forest plot: Antiretroviral therapy by nurses; Attrition. Fig. S61. Forest plot: Nurses for maintenance of antiretroviral therapy; All-cause mortality. Fig. S62. Forest plot: Exenatide; Acute pancreatitis. Fig. S63. Forest plot: DDP-4 inhibitors; Heart failure. Fig. S64. Forest plot: DDP-4 inhibitors; Hospital admission for heart failure. Fig. S65. Forest plot: Tamoxifen; Heart failure. Fig. S66. Forest plot: SGLT-2 inhibitors; Acute kidney injury. Fig. S67. Forest plot: Erythropoiesis stimulating agents; Venous thromboembolism. Fig. S68. Forest plot: Erythropoiesis stimulating agents; All-cause mortality. Fig. S69. Forest plot: Pneumococcal polysaccharide vaccines; Invasive pneumococcal disease. Fig. S70. Forest plot: Neoral (Cyclosporin); Acute rejection of kidney transplant. Fig. S71. Forest plot: Early intervention for NSTE-ACS; All-cause mortality. Fig. S72. Forest plot: Early intervention for NSTE-ACS; Myocardial infarction. Fig. S73. Forest plot: Early intervention for NSTE-ACS; Major bleeding. Fig. S74. Forest plot: Caesarean section; Anal incontinence; feces. Fig. S75. Forest plot: Caesarean section; Anal incontinence; flatus. Fig. S76. Forest plot: Ceramic-on-ceramic bearings for total hip arthroplasty; Harris Hip Score. Fig. S77. Forest plot: High-flexion total knee arthroplasty; Flexion in degrees. Fig. S78. Forest plot: Gender-specific total knee arthroplasty; Flexion-extension range. Fig. S79. Forest plot: Second generation antipsychotics; Sedation. Fig. S80. Forest plot: Second generation antipsychotics; Neurologic outcomes. Fig. S81. Forest plot: Surgery for achilles tendon rupture; Re-rupture. Fig. S82. Forest plot: Surgery for achilles tendon rupture; Complications. Fig. S83. Forest plot: High vitamin D; Hypertension. Fig. S84. Forest plot: Carotid endarterectomy; Ipsilateral stroke. FigS85-Forest plot: Carotid endarterectomy; Stroke. Fig. S86. Forest plot: Carotid artery stenting; Periprocedural stroke. Fig. S87. Forest plot: Nasal deconolization; Surgical site infection. Fig. S88. Forest plot: Glycopeptide prophylaxis; Surgical site infection. Fig. S89. Forest plot: Enoxaparin; All-cause mortality. Fig. S90. Forest plot: Enoxaparin; Major bleeding. Fig. S91. Forest plot: Enoxaparin; All-cause mortality or myocardial infarction. Fig. S92. Forest plot: Antiretroviral therapy; Tuberculosis infection. Fig. S93. Forest plot: High sugar intake; Weight gain. Fig. S94. Forest plot: High sugar intake; Body Mass Index. Fig. S95. Forest plot: Influenza vaccines; Influenza-like illness. Fig. S96. Forest plot: Mefloquine; Discontinuation due to adverse effects. Fig. S97. Forest plot: Mefloquine; Serious adverse events or effects. Fig. S98. Forest plot: Mefloquine; Nausea. Fig. S99. Forest plot: Live-attenuated zoster vaccines; Suspected Herpes Zoster. Fig. S100. Forest plot: High selenium; Cancer. Fig. S101. Forest plot: High selenium; Cancer mortality. FigS102-Forest plot: High selenium; Colorectal cancer. FigS103-Forest plot: Training for traditional birth attendants/ assistance by traditional birth attendants; Perinatal mortality. Fig. S104. Forest plot: Training for traditional birth attendants/ assistance by traditional birth attendants; Neonatal mortality. Fig. S105. Forest plot: Unicompartimental knee arthroplasty; Venous thromboembolism. Fig. S106. Forest plot: Unicompartimental knee arthroplasty; Flexion-extension range. Fig. S107. Forest plot: Unicompartimental knee arthroplasty; Operation duration. Fig. S108. Forest plot: Recombinant factor VII; All-cause mortality. Fig. S109. Forest plot: Recombinant factor VII; Thromboembolism. Fig. S110. Forest plot: Everolimus-eluting bioresorbable vascular scaffold; Stent thrombosis. Fig. S111. Forest plot: Everolimus-eluting bioresorbable vascular scaffold; All-cause mortality. Fig. S112. Forest plot: Everolimus-eluting bioresorbable vascular scaffold; Coronary heart disease mortality. Fig. S113. Forest plot: Percutaneous coronary intervention; All-cause mortality. Fig. S114. Forest plot: Percutaneous coronary intervention; Cardiovascular mortality. Fig. S115. Forest plot: Percutaneous coronary intervention; Myocardial infarction. Fig. S116. Forest plot: Digoxin; All-cause mortality. Fig. S117. Forest plot: Digoxin; Cardiovascular mortality. Fig. S118. Forest plot: Digoxin; Hospital admission.


As the organ executing gas exchange and directly facing the external environment, the lungs are challenged continuously by various stimuli, causing the disequilibration of redox homeostasis and leading to pulmonary diseases. The breakdown of oxidants/antioxidants system happens when the overproduction of free radicals results in an excess over the limitation of cleaning capability, which could lead to the oxidative modification of macromolecules including nucleic acids. The most common type of oxidative base, 8-oxoG, is considered the marker of DNA oxidative damage. The appearance of 8-oxoG could lead to base mismatch and its accumulation might end up as tumorigenesis. The base 8-oxoG was corrected by base excision repair initiated by 8-oxoguanine DNA glycosylase-1 (OGG1), which recognizes 8-oxoG from the genome and excises it from the DNA double strand, generating an AP site for further processing. Aside from its function in DNA damage repairment, it has been reported that OGG1 takes part in the regulation of gene expression, derived from its DNA binding characteristic, and showed impacts on inflammation. Researchers believe that OGG1 could be the potential therapy target for relative disease. This review intends to make an overall summary of the mechanism through which OGG1 regulates gene expression and the role of OGG1 in pulmonary diseases. Redox reaction exists widely in the manifold biochemical processes of the human body, rendering regular physiological function. Redox regulation could be achieved via controlling the activity of enzymes and transcriptional factors. Oxidative modification of the protein is the essential mechanism of redox signaling; moreover, sensing of the redox state is also part of redox regulation ,2.Redox homeostasis is generally crucial for life and is more of a dynamic balance. Free radicals, mainly reactive oxygen species (ROS) and reactive nitrogen species (RNS), produced under physiological conditions are detoxified and scavenged by antioxidants, thus maintaining at a moderate level . ExposurThe lungs are one of the organs directly in contact with the external environment and are often stimulated by external factors. Being the first interface between the internal environment and the outside world, airway epithelium is the primary target of inhaling gas or particles, which has important physiological functions in the process of sensing an injury signal, innate immune defense and regulating inflammatory response . It’s reOxidative stress pervades all principal levels, causing damages ranging from oxidative DNA damage to protein oxidation. Under physiological conditions, ROS could act as signaling factors in certain circumstances, regulating gene expression and affecting biological processes, such as proliferation, migration and angiogenesis. While excessively produced ROS could attack macromolecules such as proteins, lipids and nucleic acids, the accumulation of oxidative modification might turn into disease. With its broad involvement, oxidative stress was universally acknowledged as taking part in the genesis of pathological processes, such as tumor growth , metastaWhen it comes to the DNA oxidative damage, the function of 8-oxoguanine DNA Glycosylase (OGG1) is non-negligible, since 8-oxoG is the most common DNA oxidative damage and was fixed by base excision repair initiated by OGG1. This review collected and sorted evidence over the biological function of OGG1 and its new role as a regulator, trying to dig deep into the connection between OGG1 and pulmonary disease and figuring out its potential possibility to work as target therapy in the future. Oxidative stress can exacerbate airway inflammatory responses by which asthma, chronic obstructive pulmonary disease (COPD) and other invasive pulmonary diseases are accompanied ,23. FreeIn the course of evolution, organisms evolved complex repair pathways that maintain genome integrity and accuracy, such as base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR) and non-homologous termination (NHEJ) ,29,30,31DNA is oxidized to produce oxidative damage leading to modified bases (oxidized bases), chain break (DNA single and double chain break) and chain cross . DNA oxiIn eukaryotes, this DNA oxidative modification can be identified by the DNA glycosylation enzyme, which can repair 8-oxoG by means of base excision repair (BER) . As the N-glycosyl bonds by hydrolase activity and remove specific damage bases to produce base-free sites (AP sites), which are further treated with endonuclease and ligase. Finally, the complete repair of the original DNA sequence is realized. There are five DNA ribozymes specifically recognizing oxidized bases in mammalian cells. They are divided into two families: the Nth family including OGG1 and NTH1, and Nei family including NEIL1, NEIL2 and NEIL3 [The base excision repair process could be divided into two sections, the AP sites formation and the resolution of AP sites, executed by multiple enzymes. DNA glycosylation enzymes cut off the nd NEIL3 . These tnd NEIL3 ,40,41, and NEIL3 . N-glycoside bond [N-glycoside bond of the damaged base through the above recognition process, acting on a sugar-phosphate backbone to form an apurinic/apyrimidinic (AP)-site(s)  is a DNA repair enzyme found mainly in mammals that identifies and cleaves 8-oxoG on genomic DNA. OGG1 corrects the occurrence of 8-oxoG through a series of complex and subtle repair pathways to maintain genome accuracy. In the process, OGG1 binds to DNA containing damaged bases and bends the DNA strands, from which 8-oxoG is exposed and encapsulated in an OGG1 highly conserved catalytic active pocket, which thus cuts off the ide bond ,44,45. Aide bond ,46,47,48-site(s) b. Then, Guanine is readily oxidized, thereby disrupting the integrity of the genome. From an evolutionary perspective, vertebrate genomes contain more guanine than other organisms. OxiDIP-Seq of human MCF10A cells shows that 8-oxoG is significantly enriched in the intergenic region and the intron region of gene body, and most of the 8-oxoG are enriched in protein coding DNA . In totaExperimental evidence was widely reported in recent years. Researchers found an abnormal increase in 8-oxoG accumulation and a high spontaneous rate of lung cancer in the genome of Ogg1-/-mice . The redThe small molecule inhibitor of OGG1,TH5487 is an effective selective active site binding agent, which inhibits the activity of OGG1 DNA glycosylase, so OGG1 cannot insert itself into the DNA chain and join the 8-oxoG, and also reduces the DNA occupation of NF-κB and the level of TNFα-induced neutrophil recruitment and various cytokines in human bronchial epithelial cells and in mice models . In 2019The aforementioned studies suggest that OGG1 has immunomodulatory functions, which are closely related to promoting inflammatory cell recruitment and cytokine expression. Studying the role of 8-oxoG and its repair enzyme OGG1 in pulmonary inflammation plays an important role in elucidating the mechanism of pulmonary inflammation and developing new therapeutic targets for chronic pulmonary inflammation from the perspective of oxidative stress. Further studies show OGG1 plays a role in regulating gene transcription, called DNA repair coupled gene transcription . Genome-OGG1 can prompt inflammatory gene transcription without depending on its enzymatic activity. It could be an epigenetic mechanism to regulate innate immune responses by non-excisional binding to 8-oxoG in promoter sequences . StimulaResearchers found that there is a bidirectional interaction between OGG1 and NF-κB. OGG1 influences the combination of NF-κB to DNA through the combination of 8-oxoG, and the interaction between OGG1 and p50R sequence is more abundant. OGG1 increases the binding of NF-κB to DNA through the combination with 8-oxoG outside the κB motif, whereas the combination with 8-oxoG within κB motif reduced the binding. OGG1 not only promoted the recognition of NF-κB to conserved sequences, but also shortened the time of the recognition, whereas NF-κB could also increase OGG1-DNA binding. Through these interactions, OGG1 ultimately promotes cxcl2 expression of TNF-α stimulated cells by activating promoter activity. This plays an important role in the rapid expression of specific genes under stress conditions ,66.The regulatory model of gene transcription by OGG1 via its non-enzymatic pathways can be described as below: When an organism suffers from endogenous respiratory metabolism, products or environmental pollutants, microbial infections and a massive number of ROS product, on the one hand transcription factors are activated, and on the other hand, a lot of 8-oxoG is generated. Then, 8-oxoG is not repaired immediately; instead oxidized OGG1 bound to DNA promoter regions is recruited. OGG1 invades the DNA helix through amino acid residues, extracts the damaged base and inserts it into the OGG1’s catalytic center pocket, whereas the cytosine paired with 8-oxoG remains unmoved in the DNA helix. These events eventually cause violent bending of DNA double strands at the angle of 70° at the action site and adjacent sequences, resulting in structural changes ,67, whicIn addition, Pan et al. showed that OGG1 can regulate the expression of tissue inhibitors of metalloproteinase 1 (TIMP-1) in lung tissue through a nonenzymatic pathway . TIMP-1 To sum up, similar to DNA methylation modification (5 mC), which was regarded as a classical epigenetic marker, DNA oxidative modification (8-oxoG) also has epigenetic characteristics and can change the process of gene expression. OGG1 has a regulatory function in the early stage of transcriptions. Epithelial cells are first subjected to oxidative stimulation, then OGG1 recognizes oxidative-damaged bases produced within gene regulatory regions, changing the pattern of gene transcription. Expression changes of cytokines or chemokines in epithelial cells form the basis of pulmonary inflammation initiation, indicating a bright prospect for the design of small molecular inhibitors of OGG1 intended for inflammation control.OGG1 can modify the DNA structure through the AP sites and productions of the BER, to promote gene transcription. Hypoxia is a very common pathological process in clinical diseases, involving the expression of genes such as heat shock factors, glycolytic enzymes, extracellular matrix factors, cytoskeletal factors, apoptotic factors, cell cycle regulators and angiogenic factors . HypoxiaG-quadruplex is a special nucleic acid structure, whose constituent unit is G-quartet. G-quartet is the square planar structure formed by the binding of multiple guanines by Hoogsteen hydrogen bonds. With cations  coordination, two or more G-quartets form G-quadruplex by π-π stacking. The human genome bioinformatics analysis found that more than 300,000 genes may form G-quadruplex . The locCurrent research shows that G-quadruplexs play roles in transcription, replication and other key biological processes, such as hereditary diseases and cancer. Reportedly, genes under regulation of the promoter PQS include VEGF, PDGF-A, KRAS, HRAS, SRC, etc. In addition, PQS are rich in promoters of human DNA repair genes, suggesting the possibility of its regulation on those genes. OxiDIP and Quadron analysis in MCF-10A cells found that 37% of the 8-oxoG peaks contained potential G4 structures , most ofSpecific G-quadruplexs formed in the VEGF promoters and VEGF gene transcription can be controlled by ligand-mediated G-quadruplex stabilization . The proThe 8-oxoG in the human KRAS gene is more abundant in the G4 region than the non-G4 region. Normally, G4 sequences exist in the promoter regions of genes related to cancers such as KRAS and HRAS, thus inhibiting transcription. The high metabolic rate of cancer cells leads to increased ROS levels, which facilitate the oxidation of guanine. Attacked by ROS, cells generate 8-oxoG, which is more likely to occur inside the G-quadruplex, and the zinc finger transcription factors MAZ, SP1 and heterogeneous ribonucleoprotein A1 will bind to the G4 quadruplex to unfold it to form a DNA double helix, recruiting OGG1 to initiate the BER pathway to ensure the accuracy and integrity of the genome, which allows the recruitment of transcription factors and RNA polymerase II to promote gene transcription ,81.2O2. The Fe(II) or Cu(I)-mediated Fenton reaction could activate H2O2, thereby oxidizing G to OG, and causing the accumulation of 8-oxoG [The hormone estradiol 17β (E2) and homologous estrogen receptors (ERα and ERβ) bind to DNA elements with high affinity, promoting expression of genes related to cell cycle progression and apoptosis  and contf 8-oxoG . This acf 8-oxoG ,85,86. TCell death processes can control lung inflammation. In response to DNA damage or endoplasmic reticulum stress, when the balance of pro-apoptotic and anti-apoptotic mediators of Bcl-2 family proteins reach the level that is conducive to cell death, they will mediate cell death through intrinsic or mitochondrial pathways. Understanding the mechanisms regulating pulmonary cell death will help to identify new therapeutic targets to reduce or cure lung inflammation .The modification of DNA and chromatin plays an important role in gene epigenetic regulation. Studies have shown that OGG1 can affect gene expression by recruiting chromatin restructuring complexes. CHD4 is a key component of the complex of nucleosome remodeling and histone deacetylation (NuRD). It is essential for DNA damage repair (DDR) and is related to carcinogenesis  . The rolWhen cells are under oxidative stress, OGG1 can bind to 8-oxoG and further recruit chromodomain-helicase-DNA-binding protein 4 (CHD4). On the one hand, CHD4 will recruit DNA methyltransferases  to promote the methylation of cytosine and make this region highly methylated; On the other hand, CHD4 will recruit histone methyltransferases  to methylate histone H3, forming the trimethylation modification of H3K27 (H3K27me3) and the dimethylation modification of H3K9 (H3K9me2), thereby inhibiting gene transcription. After suppressing the expression of OGG1, researchers found that the content of 8-oxoG in the genome increased, but CHD4 could not be recruited to the promoter region of tumor suppressor genes, indicating that OGG1’s recognition and combination of 8-oxoG resulted in lower tumor suppressor genes expression. When cells are under long-term oxidative stress, the expression of tumor suppressor genes will be inhibited, which may be related to the occurrence of cancer .N-methyltransferase 5 (PRMT5), which can catalyze the symmetric demethylation of arginine-3 and cause gene silencing [A recent study confirmed the role of OGG1 in the symmetric dimethylation of histone H4-arginine-3. OGG1 binds to its DNA substrate to recruit arginine ilencing .In addition to the aforesaid mechanisms of gene expression regulation, there are studies that point out that the complex formed by OGG1 and free 8-oxoG can affect gene expression.OGG1 has high affinity with free 8-oxoG base (the binding constant Kd is 0.56 n M), and the complex formed by binding to the nonsubstrate site of 8-oxoG has a guanine-nucleotide exchange factor (GEF) activity, which does not exist in cells lacking OGG1. The OGG1-8-oxoG complex can activate canonical Ras family GTPases , such as K-RAS , N-RAS  and H-RAS (Harvey-RAS), and replace its GDP with GTP , inducinThe members of the small GTP binding protein superfamily are structurally divided into at least five subfamilies: Ras, Rho, Rab, Sar1/Arf and Ran families. Among them, the Ras subfamily members (Ras protein) mainly regulate gene expression. The Rho/Rac/Cdc42 subfamily members (Rho/Rac/Cdc42 protein) of the Rho family regulate cytoskeletal reorganization and gene expression . Rac1 isThe OGG1-8-oxoG complex can also increase the level of Rho-GTP in cells , thereby mediating the polymerization of α-smooth muscle actin (α-SMA) into stress fibers and increasing the level of α-SMA in insoluble cells/tissue and participating in lung remodeling and fibrosis (including idiopathic pulmonary fibrosis) . ResearcLung cancer ranks as one of the cancers with the highest morbidity and mortality in recent years, which is also widely reported to have close association with oxidative stress. Interestingly, there have been studies over the role of OGG1 in lung cancer separated into different directions at the very beginning. Case-control studies carried out in populations of different diseases, regions or life states, together with meta-analysis based on them, tried to figure out the correlation between OGG1 and lung cancers, and the conclusions were inconsistent. Some researchers summarized that OGG1 has no relation to a higher risk of lung cancer ,98, or iStudies over the impact of OGG1 on lung cancer also did not reach a consensus. Researchers reported that TET1 regulated the balance of hydroxymethylation and methylation in the promoter region of BER related genes, which participates in the development of lung cancer induced by environmental chemicals , and in N-diethylnitrosamine (DEN), N-methyl-N-nitrosourea (MNU), N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), N-bis (2-hydroxypropyl) nitrosamine (DHPN) and 1,2-dimethylhydrazine dihydrochloride (DMH) (DMBDD) [On the contrary, it was observed that OGG1 mutant mice manifested an increased susceptibility to the multiorgan carcinogenesis induced by  (DMBDD) , and OGG (DMBDD) . As corr (DMBDD) . Additio (DMBDD) .Airway epithelium is the main surface in contact with inhaled particles, pathogens and allergens, and is lined with a semi-impermeable barrier of highly adapted epithelial cells . EpithelRos produced in the PRR signaling pathway plays an important role in signal transduction by controlling phosphorylation. Little is known about the synergistic effects in IIR of cellular reactive oxygen species (ROS). It was proposed that OGG1 and Ataxia telangiectasia-mutated (ATM) are endogenous nuclear ROS sensors that coordinate the Pattern recognition receptor signaling pathway and regulate the innate immune response . ATM resGenes under regulation of the OGG1-8-oxoG complex are associated with some important biological processes and airway remodeling. Researchers performed an imitation of the OGG1-BER process by attacking mice lungs using 8-oxoG. In total, 1592 transcripts were identified by RNA-seq analysis . The up-Asthma is characterized by airway inflammation and hyperresponsiveness, and the tilt towards TH2 cytokines is considered to be a key risk factor for asthma. There is growing evidence that oxidative stress is also a key factor in the development of asthma. Oxidative stress levels in the lungs of asthmatics are increased and ROS produced in the cells regulates the gene expression of asthma-associated TH2 cytokine IL-4 . In addiRagweed pollen extract (PWPE), which contains NADPH Oxidase , can induce the production of a reactive oxygen species (ROS) and lead to airway hypersensitivity. Bacsi et al. found that the level of 8-oxoG increased in the airway epithelial cells of mice challenged with RWPE, and DNA SSB formed during 8-oxoG repairment enhanced antigen-driven allergic immune response . It was 2O2 exposure, and could be related to the MAPK pathway activation [In clinical work, oxygen was given as a supportive treatment for patients suffering from acute respiratory distress syndrome (ARDS). However, hyperoxia could also induce lung injury. Considering its function as a key factor in the response to oxidative DNA damage, it is natural to consider of the role of OGG1. The existence of OGG1 could help elevate the resistance to hyperoxic cytotoxicity, overexpression of hOGG1, alleviate DNA damage of A549 and AECII from hyperoxia and Htivation ,119. It tivation , as OGG1Oxidative stress has been testified to be a non-negligible risk factor for neonatal disease, especially affecting pulmonary development. Supplementary oxygen for respiratory disfunction in infants is an important source of oxidative stress, causing lung injury that manifests as delayed alveolar growth, extracellular matrix deposition and pulmonary fibrosis, which could evolve into permanent lung injury—bronchopulmonary dysplasia (BPD). Human lung morphogenesis is divided into five stages: embryonic, pseudoglandular, canalicular, saccular and alveolar. Premature infants are under a higher risk of being attacked by supplementary oxygen, since their lungs tend to be at the saccular-alveolar stage, during which lungs are more sensitive to oxidative stress . ElevateThe breakdown of redox homeostasis brings multiple organs’ diseases to the human body, among which, pulmonary diseases were closely related to DNA oxidative damage. The ROS-overproduction-induced accumulation of base mismatch has been proven to be one of the pathogenic factors of inflammation, fibrosis and tumorigenesis. Base excision repair initiated by OGG1 takes the majority of the responsibility for the correction of mismatched base pairs, since 8-oxoG is the most common type generated from oxidative attack. As the investigation over OGG1 gets deeper, research over the other perspective of OGG1 function were reported. As the big picture became complete, scientists found that during the whole process of BER, from recognition to excision, even its combination with free 8-oxoG, OGG1 impacts gene expression in multiple aspects.With the functions originated from its DNA binding characteristic come the conflicts that need to be solved. Take inflammation for example; in an hyperoxia-induced lung injury model, despite the fact that we expect OGG1 to conduct a pro-inflammation function, researchers found that overexpression of OGG1 and Fpg protected alveolar epithelial cells from toxics in oxygen-derived species . MeanwhiMoreover, when another perspective was taken into consideration, alleviation of inflammation is also a promising target for BPD treatment. Inhibition of the NF-κB pathway by either Grx1 ablation  or QuercIn summary, studies performed so far have given enough evidence that OGG1 plays important role in pulmonary diseases and show the necessity of further investigation on its relative mechanism. That is to say, problems remaining unsolved are also part of our expectations.


What was the uptake of and factors associated with COVID-19 primary and booster vaccination in the Veterans Health Administration from December 2020 to June 2022?In this cohort study of 5 632 413 enrolled veterans, cumulative incidences were 69.0% for primary vaccination, 42.9% for first booster, and 9.3% for second booster. Older age, Asian or Black race, Hispanic ethnicity, and urban residence were independently associated with receipt of vaccination.These findings suggest targeted outreach to younger, rural veterans may improve COVID-19 vaccination rates. This cohort study examines factors associated with receipt of COVID-19 vaccination and rates of vaccination among US veterans. COVID-19 vaccination rates remain suboptimal in the US. Identifying factors associated with vaccination can highlight existing gaps and guide targeted interventions to improve vaccination access and uptake.To describe incidence and patient characteristics associated with primary, first booster, and second booster COVID-19 vaccination in the Veterans Health Administration (VHA).This retrospective cohort study assessed US veterans receiving care in VHA medical centers and outpatient clinics as of December 1, 2020. All VHA enrollees with an inpatient, outpatient, or telehealth encounter in VHA as well as a primary care physician appointment in the preceding 24 months were included.Demographic characteristics, place of residence, prior SARS-CoV-2 infection, and underlying medical conditions.Cumulative incidence of primary, first booster, and second booster COVID-19 vaccination through June 2022. Cox proportional hazards regression was used to identify factors independently associated with COVID-19 vaccination.Among 5 632 413 veterans included in the study, 5 094 392 (90.4%) were male, the median (IQR) age was 66 (51-74) years, 1 032 334 (18.3%) were Black, 448 714 (8.0%) were Hispanic, and 4 202 173 (74.6%) were White. Through June 2022, cumulative incidences were 69.0% for primary vaccination, 42.9% for first booster, and 9.3% for second booster. Cumulative incidence for primary vaccination increased with increasing age, from 46.9%  among veterans aged 18 to 49 years to 82.9%  among veterans aged 80 to 84 years. More Black veterans completed primary vaccination  compared with White veterans , and more urban-dwelling veterans completed primary vaccination  compared with highly rural-dwelling veterans . Factors independently associated with higher likelihood of both primary and booster vaccination included older age, female sex, Asian or Black race, Hispanic ethnicity, urban residence, and lack of prior SARS-CoV-2 infection.In this cohort study of US veterans, COVID-19 vaccination coverage through June 2022 was suboptimal. Primary vaccination can be improved among younger, rural-dwelling veterans. Greater uptake of booster vaccination among all veterans is needed. The FDA EUA was first issued for the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) COVID-19 messenger RNA (mRNA) vaccines in December 2020 followed by JNJ-78436735 (Janssen/Johnson & Johnson) in February 2021 and NVX-CoV2373 (Novavax) in July 2022 , run by the US Department of Veterans Affairs (VA), provides comprehensive care to more than 9 million enrolled veterans in the US and worked closely with the Centers for Disease Control and Prevention and other federal partners to quickly deliver COVID-19 vaccines to veterans following initial EUA.8 The VHA affords an opportunity to evaluate vaccine uptake in different patient groups and promote equitable access to preventive care. We sought to describe incidence of and factors associated with receipt of COVID-19 primary, first booster, and second booster vaccination among VHA enrollees from December 2020 through June 2022.Despite national efforts to encourage COVID-19 vaccination, it is estimated that only approximately 77% of adults in the US had completed primary vaccination by July 2022, of whom only 51% had received a first booster dose.8 We used VA’s Corporate Data Warehouse (CDW), a relational database of VHA enrollees’ EHR data.9 The CDW includes the COVID-19 Shared Data Resource (CSDR), supported by the VA Informatics and Computing Infrastructure, and contains information on all VHA enrollees tested for or vaccinated against COVID-19.10 In addition to vaccines administered through VHA, CSDR captures some COVID-19 vaccines given outside VHA  and electronically reported to VHA or documented by VHA practitioners. To improve ascertainment of vaccination records, information on COVID-19 vaccination was supplemented with the Centers for Medicare & Medicaid Services (CMS) Medicare data for vaccination administered through Medicare services, as well as data from the VA’s Community Care program, which coordinates and reimburses local care provided outside VHA and is accessed through the Patient Integrity Tool.11 For this study, CDW and Patient Integrity Tool data were updated through June 30, 2022, and the CMS Medicare data through December 31, 2021, which represented the most recent date of available CMS Medicare data at the time of analysis. This study was approved by the VA Puget Sound Institutional Review Board, which determined that patient consent was not required. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.The VHA is the largest integrated health care system in the US, provides care at 171 medical centers and 1113 outpatient clinics throughout the country, and uses a comprehensive nationwide electronic health record (EHR) system.We identified a cohort of veterans 18 years or older enrolled in VHA and alive as of December 1, 2020. We limited the study population to VHA enrollees with an inpatient, outpatient, or telehealth encounter in VHA as well as a primary care physician appointment in the preceding 24 months.14 Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared using most recently measured weight and height. We determined the presence of 10 underlying conditions associated with adverse COVID-19–related outcomes  codes recorded in the VHA EHR and on VA Community Care service claims.16 The ICD-10 codes were also used to calculate the Charlson Comorbidity Index (CCI).18 We also determined receipt of immunosuppressive medications or cancer therapies within 2 years before cohort entry.19 To estimate baseline health care use, we ascertained the number of primary care, mental health, and specialty outpatient encounters for each veteran during the 2-year period before cohort entry.20We ascertained baseline demographic, geographic, and clinical characteristics documented in the 2-year period before the date of cohort entry on December 1, 2020. Race and ethnicity (associated with COVID-19 vaccination) were determined as reported in VHA EHR and enrollment records; other race included self-identification as other or more than 1 race. The latest zip code from the baseline period was used to determine Veterans Integrated Services Networks (VISNs) and rurality of residence based on the Rural-Urban Commuting Areas system.outcomes  based onWe aggregated all administered vaccine doses documented in the CDW, CMS Medicare, and VA Community Care records. Vaccine records with service dates before December 11, 2020, the earliest date of EUA for COVID-19 vaccination in the US, were excluded. To ensure that vaccine doses documented in more than 1 source were not counted more than once, after combining records from all sources, we treated 2 vaccine doses as duplicates if they were documented as having been received within 7 days of each other.We included mRNA-1273 , BNT162b2 (45%), and JNJ-78436735 (3%) vaccine types, which were approved in the US during the period of study and comprised most of all vaccine types. To allow for complete ascertainment of vaccination in VHA, we also included AZD1222 (Oxford-AstraZeneca) (0.01%) and NVX-CoV2373 . Vaccine doses of unknown or other type (0.01%) were excluded from the analysis.Beginning December 1, 2020, we determined the time to completion of the following vaccination end points, with follow-up extending through June 30, 2022. Primary vaccination was indicated by receipt of 2 doses of mRNA (BNT162b2 or mRNA-1273), a single dose of JNJ-78436735, 2 doses of NVX-CoV2373, or 2 doses of AZD1222 COVID-19 vaccine. First booster vaccination was indicated by any primary vaccination regimen above, followed by an additional dose of mRNA, JNJ-78436735, NVX-CoV2373, or AZD1222 vaccine. Second booster vaccination was indicated by any first booster vaccination above, followed by an additional dose of mRNA, JNJ-78436735, NVX-CoV2373, or AZD1222 vaccine.Heterologous vaccination (use of different vaccine products) was allowed for determination of primary and booster vaccination. Prior SARS-CoV-2 infection was based on the earlier of either first laboratory-confirmed SARS-CoV-2 test in CSDR or first COVID-19 diagnosis date in CMS Medicare data and ascertained as of the date of primary or booster vaccination completion.Descriptive statistics were generated for patients receiving primary and booster vaccination. Kaplan-Meier curves were used to compare cumulative incidence of vaccination by selected characteristics. Sensitivity analysis was conducted from December 1, 2020, through December 31, ,2021 comparing VA data sources alone and combined VA and CMS Medicare data.Cox proportional hazards regression was used to identify factors independently associated with time to primary and booster vaccination after adjusting for sex, age, race, ethnicity, urban vs rural residence, VISN, SARS-CoV-2 infection (modeled as a time-varying covariate), BMI, CCI, and number of primary care, mental health, or specialty care visits in the prior 2 years. We did not adjust for CCI when evaluating individual conditions to avoid overadjustment because the CCI quantifies numerous underlying conditions. Time-to-event analyses were censored on June 30, 2022, or at the time of death if earlier.3 For second booster vaccination, time-to-event analyses began on March 29, 2022, when the FDA authorized a second booster vaccination, and were limited to cohort members 50 years or older as of March 2022 who had received a first booster. Cox proportional hazards regression analyses were limited to persons who were alive and had not yet experienced the vaccination outcome of interest as of the first day of follow-up. The proportional hazards assumption was tested using log-log plot and Schoenfeld residuals. Cumulative incidence and HRs were compared using 95% CIs. Analyses were conducted in Stata software, version 17 (StataCorp LLC).For primary vaccination, time-to-event Cox proportional hazards regression analyses began on December 11, 2020, and were conducted among all eligible cohort members. For first booster vaccination, time-to-event analyses began on September 22, 2021, when the FDA authorized a booster dose of the BNT162b2 COVID-19 vaccine, and were limited to cohort members who had completed primary vaccination.We identified 8 822 259 persons 18 years or older who were enrolled in VHA and alive as of December 1, 2020. We excluded 2 455 835 veterans (27.8%) without any inpatient, outpatient, or telehealth encounters in the preceding 24 months as well as an additional 734 011 veterans (8.3%) without primary care visits during the same period. Among the 5 632 413 veterans included in the study, 5 094 392 (90.4%) were male and 538 021 (9.6%) were female; the median (IQR) age was 66 (51-74) years; 64 574 (1.1%) were American Indian or Alaska Native, 80 031 (1.4%) were Asian, 1 032 334 (18.3%) were Black, 58 643 (1.0%) were Native Hawaiian or other Pacific Islander, 4 202 173 (74.6%) were White, 5900 (0.1%) were of other race, and 188 758 (3.4%) were missing race; 448 714 (8.0%) were Hispanic or Latino, 4 946 545 (87.8%) were not Hispanic or Lationo, and 237 154 (4.2%) were missing ethnicity . The medBy June 30, 2022, a total of 32.1% of veterans were unvaccinated, 26.7% had completed primary vaccination only (no booster), and 41.2% had completed booster vaccination ; among vMore veterans of Black race completed primary vaccination  compared with White veterans . Completion of primary vaccination was also higher among Asian compared with White veterans . Incidence was lowest among American Indian and Alaska Native groups .Cumulative incidence of primary and booster vaccination was higher among veterans who had not experienced prior SARS-CoV-2 infection. Incidence increased with higher CCI; cumulative incidences for primary vaccination were 60.9% for veterans with a CCI of 0, 73.0% for those with a CCI of 1, 78.0% for a CCI of 2, and 83.0% for a CCI of 5 or higher; for first booster vaccination, 33.3%, 46.7%, 53.9%, and 61.9%, respectively; and for second booster vaccination, 5.9%, 10.1%, 13.1%, and 18.9%, respectively. Cumulative incidence of primary, first booster, and second booster vaccination was higher for veterans with conditions such as diabetes, chronic kidney disease, and COPD compared with those without the respective conditions but lower for mental health conditions, including major depressive disorder, posttraumatic stress disorder, and bipolar disorder or schizophrenia . CumulatAdjusting for demographic, clinical, and geographic characteristics , vaccinaVeterans living in highly rural areas were less likely  to complete vaccination than urban veterans . Persons experiencing prior SARS-CoV-2 infection were less likely to receive any vaccination .Veterans with higher CCIs (≥5 vs 0) were more likely to have primary vaccination  but less likely to have a first booster . Likelihood of primary vaccination also varied by individual underlying condition . Higher numbers of baseline primary and specialty care encounters were also associated with primary vaccination .In this nationwide study of 5.6 million US veterans receiving VHA care as of December 2020, the cumulative vaccination incidences through June 2022 were 69.0% for primary vaccination, 42.9% for first booster, and 9.3% for second booster. Incidence was lowest among the youngest veterans (aged 18-49 years), with 46.9% receiving primary vaccination and 15.7% receiving first booster vaccination compared with older groups (82.9% receiving primary vaccination and 62.4% receiving first booster vaccination among veterans aged 80-84 years). Incidence was also higher among veterans living in urban compared with rural areas. There was geographic variability in incidence of vaccination across VA VISNs. Accounting for demographic, clinical, and geographic differences, likelihood of primary and booster vaccination was also much higher among older veterans as well as women; Asian, Black, and Hispanic groups; and residents of urban areas.22 Although national-level surveillance provides data on demographic and geographic trends, a more complete picture that includes important clinical factors is important to informing strategies to improve vaccination access and uptake. In this study, we present the most comprehensive, longitudinal assessment of COVID-19 vaccination across VHA to date and incorporate detailed background on demographic, geographic, and clinical factors, including health care use and underlying conditions.Although COVID-19 vaccines have been demonstrated to be safe and effective, rates of vaccination across the US remain suboptimal, and booster vaccination lags well behind primary vaccination despite being broadly recommended.6 More than half (54.0%) of veterans in care aged 18 to 49 years were unvaccinated, whereas 31.1% had completed primary vaccination only. Even among veterans aged 50 to 69 years, incidence was still significantly lower than in older groups. Differences in risk perception of SARS-CoV-2 infection and related outcomes, vaccine safety and efficacy, and trust in authorities may contribute to a lower incidence and likelihood of vaccination among younger groups.23As observed in the general US population, compared with older veterans, we found that uptake of vaccination among younger veterans has remained lower.7 In VHA, during the early months after initial COVID-19 vaccine EUA, vaccination coverage was higher among Black and Hispanic veterans compared with non-Hispanic White veterans.24 Equal access to comprehensive VHA health care and targeted outreach mitigates some racial and ethnic disparities.25 Consistent with a previous study,7 we found that incidence of vaccination has remained lower for American Indian and Alaska Native groups. This finding is particularly concerning because American Indian and Alaska Native persons have been disproportionately affected by COVID-19, including higher rates of illness, hospitalization, and death.27 Continued support and targeted outreach for COVID-19 vaccination within VHA remain important to reduce these disparities.Notable differences were seen in vaccination by racial and ethnic groups, with higher incidence among Asian, Black, and Hispanic veterans compared with White and non-Hispanic groups. Following observation of early disparities in vaccination coverage among US racial and ethnic minorities, efforts to provide equitable vaccine access were undertaken to reduce this gap.28 Possible reasons for observed differences include dedicated programmatic efforts to provide care to rural veterans as well as the role of VHA and VHA practitioners as trusted sources of vaccine information.30Differences in COVID-19 vaccination by rurality were also observed, with veterans in urban areas more likely to complete primary and booster vaccination. Although the cumulative incidence of primary and first booster vaccination in this study was 5% higher among urban residents, this difference is smaller than in nonveteran populations, where the gap has increased significantly over time.24 found that the likelihood of vaccination during the first 3 months following COVID-19 vaccine EUA increased significantly among persons with higher CCIs. Although early vaccination efforts prioritized persons at highest risk for severe COVID-19 outcomes, these results indicate that, over time, higher-risk patients may have less impetus for receiving COVID-19 vaccination, despite their increased risk of severe COVID-19 outcomes.31After adjusting for demographic, clinical, and geographic characteristics, persons with a greater burden of underlying medical conditions, as measured by the CCI, had a slightly higher likelihood of primary vaccination but slightly lower likelihood of booster vaccination. In contrast, an earlier VA study32; however, overall misclassification of primary vs booster vaccination in this study is expected to be low given the relatively low prevalence in the cohort. Third, our definitions of primary and booster vaccination did not require prespecified intervals between doses,2 which may have resulted in a small degree of overascertainment of vaccination completion. In a prior VA study,24 we demonstrated that a second mRNA vaccine dose was administered within 4 days of the recommended date in 95% of cases for both BNT162b2and mRNA-1273, demonstrating excellent dosing adherence. On the other hand, we considered as duplicates any 2 vaccine doses administered within 7 days of each other, whereas other estimates did not apply this criterion.6 Comparisons of vaccination coverage reported in VA vs non-VA studies must therefore be interpreted with caution.This study has several limitations. First, although we restricted the study population to veterans engaged in care and integrated multiple data sources to strengthen ascertainment of COVID-19 vaccination, we likely did not fully capture all vaccinations received outside VHA. In addition, CMS Medicare vaccination data only extended to December 31, 2021; however, we demonstrated in sensitivity analysis that the overall absolute increase in vaccination uptake with the addition of these data was relatively small. Underascertainment of vaccination is likely to be more pronounced for booster vaccination because vaccines have become more broadly accessible in the community over time. Although the absolute vaccination rates that we report underestimate slightly the true vaccination rates of VHA enrollees, the associations and trends of different vaccination factors are likely to be consistent. Second, we did not specify primary vaccination separately for immunocompromised persons, for whom additional vaccine doses are recommendIn this retrospective cohort study of US veterans receiving VHA care, uptake of COVID-19 primary and booster vaccination remained underused, similar to trends observed in the general US population. Several important demographic and clinical factors were associated with vaccination. Younger, rural, American Indian and Alaska Native groups, and persons with a high burden of underlying conditions may benefit from targeted outreach to improve COVID-19 vaccination rates.


As Traditional Chinese Medicine (TCM) drugs, Huangqi and Danshen are always applied in combination for spinal cord injury (SCI) treatment based on the compatibility theory of TCM. Astragalus Polysaccharidesis (APS) and Tanshinone IIA (TSIIA) are the main active ingredients of Huangqi and Danshen, and they both possess neuroprotective effects through antioxidant activities. However, low solubility and poor bioavailability have greatly limited their application. In recent years, selenium nanoparticles (SeNPs) have drawn enormous attention as potential delivery carrier for antioxidant drugs.2 and regulating antioxidant selenoproteins to resist oxidative stress-induced damage.In this study, TCM active ingredients-based SeNPs surface decorated with APS and loaded with TSIIA (TSIIA@SeNPs-APS) were successfully synthesized under the guidance of the compatibility theory of TCM. Such design improved the bioavailability of APS and TSIIA with the benefits of high stability, efficient delivery and highly therapeutic efficacy for SCI treatment illustrated by an improvement of the antioxidant protective effects of APS and TSIIA. The in vivo experiments indicated that TSIIA@SeNPs-APS displayed high efficiency of cellular uptake and long retention time in PC12 cells. Furthermore, TSIIA@SeNPs-APS had a satisfactory protective effect against oxidative stress-induced cytotoxicity in PC12 cells by inhibiting excessive reactive oxygen species (ROS) production, so as to alleviate mitochondrial dysfunction to reduce cell apoptosis and S phase cell cycle arrest, and finally promote cell survival. The in vivo experiments indicated that TSIIA@SeNPs-APS can protect spinal cord neurons of SCI rats by enhancing GSH-Px activity and decreasing MDA content, which was possibly via the metabolism of TSIIA@SeNPs-APS to SeCysTSIIA@SeNPs-APS exhibited promising therapeutic effects in the anti-oxidation therapy of SCI, which paved the way for developing the synergistic effect of TCM active ingredients by nanotechnology to improve the efficacy as well as establishing novel treatments for oxidative stress-related diseases associated with Se metabolism and selenoproteins regulation.The online version contains supplementary material available at 10.1186/s12951-022-01490-x. Astragali Radix) and Danshen  are the representative drugs for supplementing Qi and activating blood circulation respectively, they are always applied in combination based on TCM compatibility theory , selenomethionine (SeMet) and selenate [Se (VI)] were the main metabolic products of selenium nanoparticles [2 and Se (IV) could be measured in the spinal cord. Additionally, the content of SeCys2 was at a high level in the SeNPs and TSIIA@SeNPs-APS groups, compared with the groups without Se treatment  to execute the bioactivity.To further understand the metabolism and bioactivity mechanism of TSIIA@SeNPs-APS, the Se biotransformation in vivo was detected. In our previous study, we had demonstrated that selenocysteine  were successfully synthesized under the guidance of the compatibility theory of TCM. Our findings can be summarized as follows. Firstly, such design improved the bioavailability of APS and TSIIA with the benefits of high stability, efficient delivery and highly therapeutic efficacy for SCI treatment illustrated by an improvement of antioxidant protective effects of APS and TSIIA. Secondly, the mechanisms of the protective effects of TSIIA@SeNPs-APS against oxidative stress-induced cytotoxicity in PC12 cells were through inhibiting excessive ROS production, so as to alleviate mitochondrial dysfunction to reduce cell apoptosis and S phase cell cycle arrest, and finally promote cell survival. Finally, TSIIA@SeNPs-APS can protect spinal cord neurons in SCI rats by enhancing GSH-Px activity and decreasing MDA content, which was possibly via the metabolism of TSIIA@SeNPs-APS to SeCys2SeO3 solution (20 mM) at room temperature. Then, 2 mL Vc solution (40 mM) was added slowly into the mixture and diluted with Milli-Q water into a total volume of 10 mL. The mixture was stirred for 12 h and dialyzed against Milli-Q water for 24 h. The concentration of Se in TSIIA@SeNPs-APS was measured by atomic fluorescence spectrometer and the concentration of APS and TSIIA in TSIIA@SeNPs-APS were detected by HPLC.1 mL APS solution (20 mg/mL) and 0.25 mL TSIIA solution (1 mg/mL) was mixed with 2 mL Na2SeO3, APS and TSIIA in the dark before the addition of Vc.Couramin-6-labelled TSIIA@SeNPs-APS for evaluation of cellular uptake and intracellular trafficking was synthesized according to the protocol of our previous study . BrieflyThe microstructure of TSIIA@SeNPs-APS was characterized by the TEM and AFM. The particle sizes and Zeta potential were analyzed by a Malvern Zetasizer Nano ZS. The chemical structure was characterized by XPS, FT-IR and UV–Vis.PC12 cells were treated with couramin-6-labelled TSIIA@SeNPs-APS for multiple times . The fluorescence intensity of couramin-6-labelled TSIIA@SeNPs-APS in PC12 cells was measured by flow cytometry as described in previous study .To investigate the mechanisms of endocytosis of TSIIA@SeNPs-APS, PC12 cells were pretreated with the endocytic inhibitor CPZ (10 μg/mL) or DOG (50 mM) or nystatin (10 μg/mL) or dynasore (80 μM) for 1 h before incubate with couramin-6-labelled TSIIA@SeNPs-APS for 2 h. Then, cells were lysed by 0.2 M NaOH (containing 0.5% Triton X-100) for 10 min. The fluorescence intensity was determined at 458/520 nm by BioTek Cytation5.PC12 cells were stained with DAPI and Lysotracker (80 nM) for 2 h. Then, cells were treated with 2.5 μM couramin-6-labelled TSIIA@SeNPs-APS and the tracks were visualized at different time points  using a fluorescence microscopy.2. The cells were seeded in a 96-well plate (10 ×104 cells/mL) and the cell viability was measured by CCK-8 assay after the following treatment.PC12 cells were purchased from ATCC  and cultured in DMEM medium with 10% FBS, 1% penicillin–streptomycin at 37 °C in an atmosphere with 5% COFor evaluating the safe dosage range of TSIIA@SeNPs-APS on PC12 cells, the cells were treated with different concentrations of TSIIA@SeNPs-APS for 24 h.For evaluating the effects of t-BOOH on cell viability reversed by TSIIA@SeNPs-APS, the cells were pretreated with 100 μM t-BOOH for 2 h and then treated with SeNPs, SeNPs-APS, TSIIA@SeNPs-APS, APS and TSIIA for 24 h, respectively.4 cells/mL). After 24 h, the cells were pretreated with 100 μM t-BOOH for 2 h and then treated with SeNPs, SeNPs-APS, TSIIA@SeNPs-APS for 24 h, respectively. After the following staining, the cells were detected by flow cytometry.PC12 cells were seeded in a 6-well plate  at 37 °C for 30 min. JC-1 fluorescence images of PC12 cells were obtained by fluorescence microscope.•+ scavenging efficiency evaluation, ABTS solution (5 mM) was reacted with manganese dioxide to obtain ABTS•+ solution. Then, the ABTS•+ solution was diluted with PBS into ABTS•+ working solution with absorbance of 0.60 ± 0.02 at 734 nm wavelength and incubated with SeNPs, SeNPs-APS and TSIIA@SeNPs-APS (300 μM) for 2 h, respectively. The absorbance was measured by a microplate spectrophotometer at 734 nm.For ABTS2O2 scavenging efficiency evaluation, H2O2 solution (100 μM) was incubated with SeNPs, SeNPs-APS and TSIIA@SeNPs-APS (300 μM) for 24 h, respectively. The H2O2 content was detected using a Hydrogen Peroxide Assay Kit .For H4 solution (9 mM) was incubated with H2O2 solution (8.8 mM) for 10 min to obtain •OH solution. Then, the •OH solution was incubated with SeNPs, SeNPs-APS and TSIIA@SeNPs-APS (300 μM) for 30 min, respectively. After that, the mixture was incubated with salicylic acid solution (9 mM) for 20 min and the absorbance was measured by a microplate spectrophotometer at 510 nm.For •OH scavenging efficiency evaluation, FeSO4 cells/mL). After 24 h, the cells were pretreated with SeNPs, SeNPs-APS, TSIIA@SeNPs-APS (2.5 μM) for 24 h, respectively. Next, PC12 cells were stained with DCFH-DA (10 μM) at 37 °C for 30 min. Then, the cells were treated with t-BOOH (100 μM) before the fluorescence intensity was determined at 458/520 nm by BioTek Cytation5. DCFH-DA fluorescence images of PC12 cells were obtained by fluorescence microscope.PC12 cells were seeded in a 96-well plate . Rats in sham group were only subjected to surgery of laminectomy but no impact injury to the spinal cord. Finally, the wound was sutured in layers. As prophylactic for infections, penicillin was given by intramuscular injection, with dose of 16 × 104 U per animal, once a day, 3 consecutive days from the day of surgery. Bladder care was conducted twice daily until bladder function resumed.2 months old female Sprague–Dawley rats weighing 200 to 220 g were purchased from Guangdong Medical Laboratory Animal Center . The SCI rat model was performed as described in previous study . BrieflyThe rats were randomly assigned to six groups: sham, SCI, APS, TSIIA, SeNPs and TSIIA@SeNPs-APS group. SeNPs and TSIIA@SeNPs-APS were administered intraperitoneally at a dose of 1 mg/kg . APS and TSIIA were administered intraperitoneally with the same concentration of that in TSIIA@SeNPs-APS. Rats in the sham and SCI group were received the same amount of saline. All rats underwent treatment once a day, for 21 consecutive days.On the 21th day after treatment, behavioral assessments were performed before all rats were sacrificed. Then, the spinal cord, heart, liver, spleen, lungs and kidneys were harvested for follow-up experiments.Behavior evaluation was conducted using the BBB test, inclined plane test, footprint analysis and hindlimb movement analysis. The BBB score was calculated as mentioned previously . The scoFixed spinal cord tissue was subjected to dehydration, dipping in wax, embedding and sectioning at a thickness of 4 μm and then H&E, Nissl and TUNEL/DAPI double-staining were performed as mentioned previously . The obsCold PBS supplemented with protease inhibitors were added to fresh spinal cord tissue. Then, each tissue was homogenized using a Tissuelyser-24  with the parameters of 35 Hz and 60 s for three times to obtain the spinal cord homogenates. TSIIA@SeNPs-APS were incubated in injured spinal cord homogenates at 37 °C for 24 h. Images were taken by TEM.Metabolism analysis of TSIIA@SeNPs-APS were measured as previously reported  . BrieflThe antioxidant ability of TSIIA@SeNPs-APS in vivo by measuring the activity of GSH-Px and the content of MDA in the spinal cord. Briefly, the spinal cord homogenates were obtained by RIPA Lysis Buffer containing protease inhibitors and the protein concentration was examined by a BCA protein assay kit. Then, spinal cord homogenates were examined to detect the activity of GSH-Px and the content of MDA using the corresponding assay kit  according to the specification method.Expression of different proteins in vitro and in vivo were analyzed by western blot. Proteins were extracted by RIPA Lysis Buffer with protease inhibitors and then separated on SDS-Page and transferred to PVDF membranes , which were then blocked and incubated with the specific primary antibody. Next, the membranes were incubated with secondary antibodies. Protein bands were visualized by ECL kit  before imaged by a Tanon 5200 imaging system. All bands were quantified by ImageJ.−ΔΔCt method.  and transcribed to cDNA by an Evo M-ML V RT Premix Kit . The qPCR was performed by using SYBR Green qPCR Master Mix  on a CFX ConnectTM Real-Time PCR Detection System . β-actin was used for normalization. Relative mRNA expression was analyzed using the 2Additional file 1: Table S1 Sequences of the qPCR primers used in this study. Figure S1 ROS scavenging efficiency of (1) APS, (2) TSIIA and (3) TSIIA@SeNPs-APS by ABTS method