Background: Ursolic acid (UA) is a natural pentacyclic triterpene derived from fruit, herb, and other plants. UA can act on molecular targets of various signaling pathways, inhibit the growth of cancer cells, promote cycle stagnation, and induce apoptosis, thereby exerting anticancer activity. However, its poor water-solubility, low intestinal mucosal absorption, and low bioavailability restrict its clinical application. In order to overcome these deficiencies, nanotechnology, has been applied to the pharmacological study of UA.Objective: In this review, we focused on the absorption, distribution, and elimination pharmacokinetics of UA in vivo, as well as on the research progress in various UA nanoformulations, in the hope of providing reference information for the research on the anticancer activity of UA.Methods: Relevant research articles on Pubmed and Web of Science in recent years were searched selectively by using the keywords and subheadings, and were summarized systematically.Key finding: The improvement of the antitumor ability of the UA nanoformulations is mainly due to the improvement of the bioavailability and the enhancement of the targeting ability of the UA molecules. UA nanoformulations can even be combined with computational imaging technology for monitoring or diagnosis.Conclusion: Currently, a variety of UA nanoformulations, such as micelles, liposomes, and nanoparticles, which can increase the solubility and bioactivity of UA, while promoting the accumulation of UA in tumor tissues, have been prepared. Although the research of UA in the nanofield has made great progress, there is still a long way to go before the clinical application of UA nanoformulations. Cancer is a complex disease caused by the abnormal proliferation of cells under the action of multiple factors . Over th30H48O3 and a molecular weight of 456.7 g/mol, is a natural arbutin pentacyclic triterpenoid, which is widely found in fruits, medicinal materials, and other plants  has good solubility; however, its solubility in water is low, leading to poor oral drug absorption in the body, short half-life, and low bioavailability. These disadvantages limit its wide application in the pharmaceutical field, and it has been classified as class IV in the biological drug classification system (BCS) . UA has Nanoformulations have broader prospects in the field of anticancer research, with the successful marketing of doxorubicin long-cycle liposomes and paclitaxel albumin nanoparticles. The enhanced permeability and retention effect   of UA in Caco2 cell monolayers decreases from 2.7 × 10−6 to 2.3 × 10−6 cm/s. Therefore, to some extent, UA acidification or sulfurization results in low UA bioavailability  . One stuet Zucc) . Anotheret Zucc) . The abset Zucc) . UA contlability .Hedyotis diffusa Willd) was administered to healthy Sprague-Dawley rats, organ samples were collected. The tissue concentrations of UA were measured in the liver, kidneys, spleen, heart, and lungs. In addition, the distribution of UA in C57BL/6 mice was analyzed, and the results also showed that the concentrations of UA in the liver, kidneys, and heart increased gradually with the observation time , half-life time elimination (t1/2β 40.94 ± 4.91 h), and maximum plasma concentration (Cmax 487.47 ± 138.94 ng/ml)  enzymes are among the most important metabolic enzymes in the liver. Thus, in the experiments on Caco2 cells and Caco2-PXR-RXRα cells, the Km values of UA are 81.99 ± 44.32 and 60.05 ± 29.62 g/mL, respectively, and the ectively . In addiectively . A pharm4 ng/ml) . These r4 ng/ml) . Experim by LogP . In the  by LogP .However, it is worth noting that owing to the low solubility of UA, some residues remain in the digestive tract after oral administration, and the intestinal microflora may metabolize UA. The intestinal tract has a special microbiome, which is different from the physiological environment of the liver. Therefore, the metabolic transformation process of UA in the intestinal tract is specific and worthy of further study. The results of the study on UA and intestinal flora showed that UA could reduce the dosage of antimicrobials by 8 times . UA has β-glucuronidase or sulfate esterase, resulting in poor absorbed blood content. UA is mainly distributed in liver after absorption, which may be related to the transport mediated by OATPs. The concentration of UA in the liver and kidney is increased in a time dependent manner, which may be related to blood perfusion. The metabolism of UA in liver is closely related to the enzyme activity of CYP and NADPH. According to existing studies, we know that only a very small amount of UA is eliminated by renal excretion. Up to now, the pharmacokinetic study of UA still needs further exploration.In summary, UA is a hydrophobic drug with poor solubility and oral bioavailability. Hence, it is difficult to exert significant cytotoxic activity. UA is absorbed rapidly by the intestinal tract mainly through passive diffusion, and is also affected by exogenous protein P-glycoprotein or As the gastrointestinal mucosa permeability of UA is poor and its oral absorption rate is low, the UA-related nanoformulations are designed so as to be administered mainly intravenously to prevent the gastrointestinal absorption process of UA and improve the drug delivery efficiency to the site of action. The basic characteristics and related anticancer research results of UA nanoformulations are shown in It should be noted that the enrichment of nanoformulations into tumor tissues is inevitable through the tumor microenvironment, where the pH value is more acidic than that of normal tissues, and tumor tissues and their cells contain higher concentrations of glutathione (GSH), reactive oxygen species (ROS), and highly expressed metabolic enzymes . Thus, iPolymer micelles are new nanocarriers formed by the self-assembly of copolymers in aqueous solutions. They are usually amphiphilic and have a nucleus-shell structure with a hydrophobic core and a hydrophilic shell . The hyd−3 mg/mL, respectively, which showed good micelle stability and increased circulation time in the blood. In addition, the release of the UA-PMs at pH 7.4 and 5.5 was evaluated at 37°C owing to the microenvironment of the tumor tissues with microacidic properties. The results showed that the UA release of the UA-PMs was significantly comparable  and there was no obvious initial outburst, indicating that the micelles had controlled release behavior and could increase the accumulation of UA at tumor sites to some extent. This could be because UA is protected from degradation by the polymer micellar hydrophobic core. In addition, compared with free UA, the proliferation and migration ability of HepG2 cells are reduced to a certain extent with the increase in the UA-PM concentration. Moreover, neither free UA nor UA-PMs are significantly toxic to L-02 cell lines. Interestingly, UA and UA-PMs promote L-02 cell proliferation at low concentrations (approximately <60 um). In animal experiments, UA-PMs showed stronger tumor inhibition than free UA at the same concentration; additionally, they showed a concentration-dependent tumor inhibition rate  using mPEG-PLA  by membrane dispersion, and investigated its the proliferation inhibition effect on HepG2 (human liver cancer cells), L-02 , and H22 (mouse liver cancer cells) cell lines. The ratio of UA to the carrier was approximately 1:10, and the micelle was smooth and spherical. The average particle size, zeta potential, polymer dispersion coefficient, and the critical micelle concentration was 29.35 ± 0.38 nm, −0.75 ± 1.30 mV, 0.299 ± 0.005, and 2.3 × 10ion rate .in vivo, so as to meet the requirements of targeted and controlled release . This may be related to the slow release of liposome drugs after modification, and the increased observation time (24 h of cell culture in vitro in this study), which may yield opposite tumor suppressive results  , while the intracellular lysosome pH was lower than 6.0 . This st3.07 µM) . However3.07 µM) . This coActively targeted liposomes are prepared by adding some targeting materials to liposomes, which can further increase the accumulation of drugs in tumor tissues. Folic acid (FA) receptors are widely used in targeted delivery systems because of their high expression in many cancer cells and low expression in normal tissues, as well as the high affinity between FA molecules and FA receptors or folate-binding proteins expressed in cell membranes . By usin50 is significantly lower than that of non-targeted liposomes (22.05 vs. 146.3 µM). Moreover, the cytotoxicity of folate-targeted UA liposomes induced by apoptosis is significantly dose- and time-dependent  drug delivery efficiency. Subsequent anti-cancer studies have produced better results. Folate-targeted UA liposomes significantly reduce the tumor volume of tumor-bearing mice (by approximately 55%), and their ICependent . In anot effects .In addition to FA molecules, glycosyl-specific binding receptors are also highly expressed in the cell membrane of human tissues. Therefore, it would be worth considering to add polysaccharide-modifying components, such as hyaluronic acid (HA) molecules, in the liposome structure to improve targeting. Sun et al., successfully prepared UA containing nanoliposomes encapsulated in hyaluronic acid, which showed better anti-liver cancer activity than 5-fluorouracil. However, it should be mentioned that UA was not the only drug targeting tissues in this study; ginsenoside and oleanolic acid (OA) were used as well .It is worth noting that the tumor microenvironment is complex and changeable, and there may be pH value, enzyme activity, and ROS content differences overall or depending on the layer. Therefore, a single modification cannot fully cope with the microenvironment and all the accompanying changes. Therefore, in order to achieve higher transmission efficiency and better therapeutic effects, multifunctional liposomes with reasonable superposition of different modification modes have been developed by scientists.l-lysine (PLL) and HA in recent years. This nanoliposome can enable drugs to locate tumor sites more accurately and improve their bioavailability at target sites. PLL is a cation that is pH-responsive by protonation. HA is an anion that reacts with hyaluronidase (HYAL) in tumor tissues and enters cells by binding specifically to CD44 receptors. In the aforementioned study, cholesterol (Chl), phosphatidylcholine (PC), and UA were prepared into UA liposomes (UA.P) at a ratio of 1:2:0.5. The particle size and zeta potential were 85.7 ± 1.5 nm and −19.3 ± 0.2 mV, respectively. On this basis, UA-PLL.P was constructed by coating the PLL layer with a liposome with a particle size of 91.3 ± 1.1 nm and zeta potential of 32.6 ± 0.2 mV. Finally, the HA layer was coated with a liposome with a particle size and zeta potential of 102.0 ± 3.0 nm and −8.5 ± 1.1 mV, respectively, to construct UA-PLL-HA.P. The results showed that the sustained release time of UA liposomes was significantly prolonged after surface modification. Additionally, UA-PLL-HA.P had the highest release efficiency of only 38% at 80 h under acidic conditions (pH = 5.0), which was due to the protection of the HA layer. After adding HYAL, the release of UA-PLL-HA.P was approximately 70% within 20 h. Subsequent trials also showed that UA-PLL-HA.P had higher cytotoxicity and better anticancer efficacy than UA.P and UA-PLL.P. When the compound UA and two liposomes, UA.P and UA-PLL-HA.P, which were equivalent to 100 g/mL UA, were applied to SCC-7 cell lines for 24 h, the cell mortality was 45, 51, and 67%, respectively, and increased to 59, 65, and 79% after 48 h, respectively. Similar results were obtained when the same method was applied to BT-474 cell lines. Despite multiple modifications, the UA liposomes in this experiment also exhibited biphasic release. In other words, multiple modifications resulted in higher sustained release efficiency of UA liposomes compared with a single modification, but the sudden release did not seem to be improved  is a type of thermodynamically stable, colloidal dispersion system spontaneously formed by water and oil phases, surfactants, and co-surfactants in proper proportions . The sur50 was between 0.58 and 2.9 µM). Unfortunately, this nanoemulsion contains both UA and OA, and UA is not the only active drug. In the UA and OA nanoemulsion system, the average droplet diameter is approximately 198.95 ± 21.34 nm, with good stability and no obvious aggregation or deposition. In addition, in this study it was also observed that the emulsion prepared had a significant antioxidant effect, and the inhibition rate of 2,2-Diphenyl-1-picrylhydrazyl (DPPH), a stable free radical, was approximately 88%  polymer nanoparticles and inorganic nanoparticles, are new drug carriers with great potential for development. The former are generally made using chitosan, polylactic acid, polycaprolactone, and other natural or synthetic polymers, while the latter are generally made using inorganic materials such as carbon, silicon dioxide, and bioceramics . With reChitosan is the only alkaline polysaccharide among natural polysaccharides. As a new nanosystem carrier, chitosan has good biocompatibility and biodegradability . UA has 50:82.5 vs. 56.7 μg/mL). In the mouse hepatocellular carcinoma model, no significant microangiogenesis was observed under the action of CH-UA-NPS; on the contrary, a high amount of tissue necrosis was observed. Cell necrosis may be related to the destruction of lysosomes and the mitochondrial membrane structure owing to CH-UA-NPS entering the cell. The inhibitory effect of CH-UA-NPS on angiogenesis was also observed in a chick embryo chorioallantoic membrane model. Notably, CH-UA-NPS has also been shown to have a good anti-breast cancer effect. FA is a widely used targeting molecule  with a drug loading rate of approximately 54% and a particle size of approximately 100 nm. The results of both cell and animal experiments showed that CH-UA-NPS has a significant inhibitory effect on angiogenesis. Compared with free UA, the killing effect of nanoparticles on human umbilical vein endothelial cells was more obvious at the same concentration for 24 h (ICmolecule .The successful synthesis of folate-targeting UA chitosan nanoparticles (FA-CS-UA-NPS) has been reported in a study . Similarin vivo release process of the nanoparticle, which has the ability of continuous slow release  after an initial sudden release . This suggests that by extending the observation cycle further, we may be able to observe more significant cellular lethality.Polylactic acid (PLA), a product of a certain amount of lactic acid condensation reaction, is a biodegradable polymer material with good biocompatibility and is an ideal carrier for drug-carrying nanoparticles . One stu50 of UA and UA-NPS was 59.84 ± 4.12 and 32.89 ± 3.23 µM, respectively. Compared with UA, UA-NPS exhibited stronger tumor suppressive ability in H22 transplanted mice treated with UA and UA-NPS. CT images of the mice showed that UA alleviated most tumor lesions, while the UA-NPS group was almost completely exhausted. Further studies demonstrated that this could be because UA and UA-NPS increased the expression of Bax and Caspase-3 and decreased the expression of Bcl-2, while UA-NPS decreased the expression of Bcl-2 more clearly (Polycaprolactone (PCL) is also a biodegradable polymer material that is chemically synthesized. Zhang et al., successfully prepared UA-containing polycaprolactone nanoparticles (UA-NPs) with an encapsulation rate of over 80%. UA-NPs also exhibited a biphasic release similar to that of the aforementioned PLA nanoparticles, with UA release rates of approximately 28% within 8 h. Both UA and UA-NPS can induce the death of H22 HCC cells, but the latter is more cytotoxic. The IC clearly .50 of 18 μM and a free IC50 of 60 μM. Similarly, the nanoparticles exhibited a biphasic release, and approximately 30% of UA was released within the first 4 h (A Poly (lactic-co-glycolic acid) (PLGA) consists of the random polymerization of two monomers, lactic acid and glycolic acid. It is also a biodegradable functional polymer organic compound with good biocompatibility, good sac formation performance, and good membrane formation . One stuirst 4 h . Studiesirst 4 h . One stuirst 4 h . In one irst 4 h . Both naNanoparticles prepared from materials such as chitosan, polylactic acid, and polycaprolactone are biodegradable nanoparticles . They maThe pH-sensitive MSN drug delivery system is a common controlled release system in the MSN drug delivery system, which allows the drug to be released well in acidic tumor tissues. Li et al., successfully prepared pH-sensitive MSNs containing UA. The release test results showed that the UA release rate at pH 5.5 was higher than that at pH 7.4 (60 vs. 40%). In addition, the experiment showed that, compared with free UA, the MSNs infiltrated rapidly HepG2 cells, inhibited significantly the cell cycle, and promoted apoptosis . The pH-Nanocrystals  usually refer to the nanoscale dispersion system of pure drugs dispersed in liquid in crystalline or amorphous form, with a small amount of either a surfactant or polymer as a stabilizer . General50 value of approximately half that of free UA. Generally speaking, the smaller the nanocrystal particle size, the faster the drug is dissolved, and thus, better absorption may be achieved. However, the particle size and distribution of the drug in nanocrystals change constantly when the drug is put to rest. The results of the aforementioned study showed that the diameter of the UA nanosuspensions increased to 199.5 nm after 49 days at 4°C. In order to keep the particles in the suspension stable and prevent agglomeration or settlement, it is necessary to add a proper stabilizer to the suspension. However, it should be mentioned that the nanocrystalline was prepared without a stabilizer, and the desired stability was obtained nonetheless. The specific principle needs to be studied further. It is worth noting that the stability may be temporary, because the polymer dispersion coefficient value also increases to a certain extent as the grain size increases to 199.5 nm  is a clinical near-infrared light (NIR) fluorescent dye with excellent biocompatibility and approved by the FDA. It has been applied in many fields, such as the imaging diagnosis of diseases and photothermal therapy . NanoparGuo et al., combined UA, PTX, and ICG into a carrier-free spherical nanoparticle (ICG @ UA/PTX NPs) with a particle size of approximately 130.8 nm and good stability, even if stored in an aqueous solution for 20 days. This may be due to the electrostatic and hydrophobic interactions between the co-assembled nanoparticles. After 5 min of NIR laser irradiation, the temperature of the NPs increased from 39 to 65°C. The cell test showed that, compared with NIR-free cells, the nanoparticles had more significant cytotoxicity on HepG2 cancer cells and HeLa cells under the action of NIR laser. The H22 tumor-bearing mouse model was used in the animal experiments. The results showed that the tumor volume of mice exposed to NIR nanoparticles decreased significantly compared with that of other groups, and there was no tumor recurrence during the 21-days observation period. Although the study showed that a large number of ICG @ UA/PTX NPs were endocytosed by HepG2 cancer cells within 3 h, in another study, the prepared nanoparticles were added with hepatotargeting LA molecules. Finally, the nanoparticles UA-LA-ICG NPs were prepared, making the intracellular fluorescence intensity stronger . The deaThe UA nanoformulations, combined with chemotherapeutic agents, allows for more precise release of cargo to its destination. And depending on the design, it can be released simultaneously or sequentially during transmission, creating synergies and enhancing therapeutic effects. UA was chemically conjugated to low molecular weight heparin (LMWH) to produce micellar LMWH-UA, which improves the efficacy of LMWH against tumor angiogenesis and reduces the risk of bleeding in cancer therapy. Experimental observations have demonstrated that LMWH-UA successfully reduces the risk of bleeding by reducing the affinity of antithrombin. The degradation of LMWH-UA in the plasma was 6.64 ± 0.87% after 72 h, indicating that LMWH-UA has good stability in the plasma. LMWH-UA shows high affinity to mouse melanoma B16F10 cells through specific polypeptide-mediated endocytosis .in vivo, about six times that of PTX alone. In addition, UA and PTX were observed to block MCF-7 tumor cell proliferation and induce apoptosis through different mechanisms, respectively, both of which had synergistic anti-tumor effect and reached a tumor inhibition rate of 90%  in 2010, however, only a few pharmacokinetic parameters were observed to demonstrate the success of the new detection methods. The values of maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax), half-life (t1/2), area under the plasma concentration time curve (AUC0→t), and AUC0→∞, were 3,404.6 ± 748.8 ng/mL, 4.0 ± 0.0 h, 3.9 ± 2.1 h, 9,644.1 ± 1,193.2 ng h/mL, 9,918.4 ± 1,215.2 ng h/mL, respectively , indicating to some extent that no drug accumulation was observed after repeated administration. In the whole study, UA liposom-related adverse events were mostly mild to moderate, and the common adverse reactions were nausea, diarrhea and abdominal distension, indicating that UA liposomes were well tolerated  with the purpose of determining the efficacy and safety of the drug under test . Althougectively . Zhu et olerated . Wang etrated  that can be achieved after administration of UA nanoformulations in vivo are 2–3 times that of the original UA molecules (The research of natural molecule UA in the nanofield has made great progress. Through extensive inquiry and research, we have summarized the main antitumor research achievements of current UA nanoformulations in olecules . Moreoveolecules . Finallyolecules .in vivo, resulting in membrane permeability changes and drug leakage. Micelle has a unique cored-shell structure, but compared with other common types of nanomaterials, the drug loading of micelle is usually less, which may make it difficult to exert the expected therapeutic effect of UA (Currently, the design of UA nanoformulations is very diverse according to the purpose, whether to increase the stability of drug circulation, or to release drugs slowly and effectively, reduce the accumulation of non-targeted sites. On a certain extent, they all aimed to increase the efficacy of UA and promotes its better clinical application. Liposomes are basically perfect systems with components similar to biofilm compositions and are designed to move drug molecules across specific cell membranes, offering excellent drug delivery potential . Howeverct of UA . Nanocryct of UA .in vivo was enhanced after the encapsulation of the carrier. However, the carrier occupies a large proportion in the whole nanosystem, which affects the drug loading efficiency of nanoformulations (Also, PCL, PLA, PLGA, MSNs, chitosan, and other materials are commonly used as nano-delivery carriers for UA nanoformulations. Safety is an important driving force for the use of nanocarriers as pharmaceutical excipients. After the drug has been delivered to the site, the carrier material itself should be completely excreted within a reasonable period of time, or its metabolites should be clear and non-toxic. Chitosan is a natural cationic polysaccharide, which can make drugs enter cells by interacting with negatively charged residues in membrane proteins . PLA is ulations . TherefoAlthough research on UA nanoformulations has progressed adequately, there are still some problems to be solved. The ideal nanoformulations should be able to penetrate the core of a tumor tissue at a high drug concentration, enter the tumor cells where the target molecules are located, completely eradicate the tumor, and improve the survival rate of patients. This involves five steps: entering the blood circulation, enriching the tumor site, infiltrating the tumor tissue, reaching the tumor cells, and being ingested by them. Finally, the drug is released inside the cell . Tumor tThe permeability of nanoformulations is related to the heterogeneity of the tumor microenvironment . Nanoforin vivo have not been fully elucidated, so in-depth preclinical experimental and clinical trial explorations are necessary. Establishing large animal models of various cancer types, or combining mathematical models to simulate and track the in vivo behavior of UA nanoformulations may be beneficial to further evaluate their in vivo characteristics (As research progresses, the delivery efficiency of UA nanoformulations may be improved significantly; however, there is still a long way to go before clinical application. To date, the physicochemical properties and metabolic behavior of UA nanopreparations eristics . Anothereristics . At presThis review highlighted the advantages and disadvantages of UA as a natural plant-based anticancer compound, indicating that new cancer treatment strategies based on nanotechnology for UA have broad clinical application prospects. The mature application of nanotechnology in the field of medicine has smoothed the path of cancer treatment. Based on the EPR effect, nanoformulations selectively concentrate in tumor tissues and reduce the distribution of normal tissues, which, to some extent, enhances the anticancer efficacy of drugs and reduces drug-induced adverse reactions. Currently, a variety of UA nanoformulations, such as micelles, liposomes, nanoparticles, and nanocrystals, which have higher stability, better absorption rates, and higher cancer cell lethality than UA compounds, have been prepared successully. The main properties of UA nanoformulations and their therapeutic efficacy are shown in


Ursolic acid (UA) is a natural pentacyclic triterpenoid found in a number of plants such as apples, thyme, oregano, hawthorn and others. Several in vitro and in vivo studies have presented its anti-inflammatory and anti-apoptotic properties. The inhibition of NF-κB-mediated inflammatory pathways and the increased scavenging of reactive oxygen species (ROS) in numerous ways seem to be the most beneficial effects of UA. In mice and rats, administration of UA appears to slow down the development of cardiovascular diseases (CVDs), especially atherosclerosis and cardiac fibrosis. Upregulation of endothelial-type nitric oxide synthase (eNOS) and cystathionine-λ-lyase (CSE) by UA may suggest its vasorelaxant property. Inhibition of metalloproteinases activity by UA may contribute to better outcomes in aneurysms management. UA influence on lipid and glucose metabolism remains inconsistent, and additional studies are essential to verify its efficacy. Furthermore, UA derivatives appear to have a beneficial impact on the cardiovascular system. This review aims to summarize recent findings on beneficial effects of UA that may make it a promising candidate for clinical trials for the management of CVDs. According to the World Health Organization, nearly 41 million deaths out of 55 million worldwide were caused by non-communicable diseases (NCDs) in 2016, representing 75% of global mortality. NCDs are not transmissible directly from one to another person, and this group of disorders includes autoimmune diseases, diabetes, cancers, cerebral strokes, respiratory diseases, cardiovascular conditions and others . AlthougThis review summarizes recent investigations of biological activity of UA and its derivatives in the cardiovascular system.Ganodema lucidum, Boswellia serrata, Aster tataricus and Potentila discolor, are also abundant in PTs [PTs constitute a structurally diverse group of natural products derived from squalene cyclization . Three mt in PTs . In plant in PTs . In humat in PTs . Therefot in PTs . Moreovet in PTs . The ver30H48O3 and 456.7 g/mol, respectively. It is acidic, has poor solubility in water and is needle-like or a crystalline solid [UA (3β-hydroxy-urs-12-en-28-oic-acid) belongs to the ursane-type pentacyclic triterpenoids, having a C-3 hydroxyl group and C-28 carboxylic acid group. The molecular formula and weight of UA are Cne solid . The bione solid . After ine solid ,18. UA cne solid . Moderatne solid ,20. UA ene solid . Atherosclerosis is a multifactorial disease with accelerated endothelial damage, which leads to an invasion of inflammatory cells into the tunica intima and adhesion of platelets. Macrophages derived from monocytes are involved in the inflammatory response and the deposition of fats, cholesterol, calcium and other substances that contribute to lipid storage and dynamic atherosclerotic plaque growth in the vascular walls. Over time, plaque hardens and arteries stiffen, which limits the flow of blood and consequently results in a hypoxic state in vital organs . Since atherosclerosis is a chronic inflammatory state, different factors responsible for the constant recruitment and accumulation of immune cells  in plaques have been investigated. The loss of biologic activity of endothelium is associated with the increased expression of pro-inflammatory adhesion molecules, cytokines and chemotactic factors such as monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin and others . FurtherUllevig et al. showed reduced atherosclerotic lesion formation in high-fat diet-fed diabetic mice that were LDL receptor-deficient (LDLR−/−) after 11 weeks of UA supplementation. This result was possibly obtained by the decreased release of MCP-1 from sites of vascular injury or inhibited responsiveness of monocytes/macrophages to these molecules without changing MCP-1 receptor (CCR2) surface expression. It is worth mentioning that blood glucose level was significantly reduced, whereas plasma lipid levels were not improved. In addition, UA was more effective in plaque reduction than a well-known antioxidant resveratrol  . LikewisThe impact of UA on atherosclerosis is the subject of dispute amongst many researchers; thus, some of them decided to investigate UA activity mainly on HUVECs. The study of Steikamp-Fenske et al. presented that UA upregulated endothelial-type NO synthase (eNOS), which produces nitric oxide (NO). NO is a molecule that promotes vascular relaxation and protection from thrombosis and atherogenesis. In addition, it was found that UA reduced the expression of Nox4 (NADPH oxidase subunit), which is the predominant source of reactive oxygen species (ROS) . ROS impThe decreased production of intracellular ROS was also presented by Lin et al., who investigated the effect of UA on resistin-induced adhesion of histiocytic lymphoma cells to HUVECs. The study resulted in a suppressed adhesion between cells and downregulated expression of adhesions molecules such as VCAM-1, ICAM-1 and E-selectin due to inhibited nuclear translocation of NF-κB. It is worth mentioning that resistin, an obesity-induced adipokine, stimulates the expression of the mentioned adhesion molecules on the surface of endothelial cells, which causes accumulation of inflammatory cells in the early stage of atherosclerosis . SimilarInterestingly, Takada et al. compared anti-atherogenic properties of two PTs: UA and oleanolic acid in HUVECs. Both of them inhibited TNF-α-induced E-selectin expression and parallel NF-κB activity. However, the UA bioactivity was attained at lower concentrations in comparison to oleanolic acid . The advFurther research has been investigated in various directions. In a paper by Jiang et al., the authors described an anti-proliferation effect of UA in rat primary vascular smooth muscle cells (VSMCs). The obtained result was associated with inhibition of microRNA-21, whicht subsequently enhanced PTEN expression and then downregulation of PI3K (a molecule participating in proliferation) . VSMCs wLow-density lipoprotein cholesterol (LDL-C) is the primary driver of atherogenesis and the key deliverer of cholesterol to the artery wall. The treatment of atherosclerosis is based on lipid-modulating therapies, which modify lipid profile by raising high-density lipoprotein cholesterol (HDL-C) and lowering LDL-C levels. Reduced LDL-C concentration is associated with lower rates of major coronary events . Cholest2 and upregulation of eNOS activity. In addition, significant reduction in aorta thickness in a dose-dependent manner was observed [The impact of UA on plasma lipids in mice were investigated in the previous studies, but none of them showed any improvement ,25,26,27observed . Anotherobserved .Statin drugs as HMG-CoA reductase inhibitors allow gaining impressive reductions in LDL-C . Since UThe summary of the studies describing UA’s impact on atherosclerosis in vitro and in vivo is shown in Nepeta deflersiana extract, in which UA was one of nine secondary metabolites isolated from the plant. In addition to results similar to the previous studies, suppressed NF-κB activity in cardiomyocytes and decreased levels of TNF-α, IL-6 and IL-10 were described [Myocardial infarction (MI) is the irreversible necrosis of heart muscle due to prolonged restriction in blood supply causing a lack of oxygen. The rupture or erosion of a vulnerable atherosclerotic coronary plaque is the most common cause of MI . In acutescribed . The restoration of blood flow to the ischemic myocardium may be associated with further myocardial injury. Apoptosis, autophagy and oxidative stress are involved in this harmful process. However, an increased level of uncoupling protein 2 (UCP2), a cationic carrier protein, appears to possess a protective effect in hypoxia–reoxygenation injury. Thus, Chen et al. tested six natural compounds in rats cells under ischemia–reperfusion conditions. Among them, UA exhibited the most effective impact on UCP2 expression, which was possibly attained by inhibition of p38 signaling pathway. Furthermore, the authors noted an anti-apoptotic property based on depleted caspase-3 activity and antioxidative effect through decreased ROS production, MDA content and increased SOD activity .1 in the heart, while the level of MMP-2 almost normalized compared to the control group. In addition, this was the second study in which blood glucose level was decreased [1 is one of the best-characterized fibrogenic growth factors, and its presence induces collagen deposition, inhibition of interstitial collagenases and extracellular matrix protein synthesis. TGF-β1 activation is dependent on other molecules such as MMP-2, MMP-9 and TSP-1 [1 by UA may imply its strong anti-fibrotic property. Dong et al. tried to expand the biochemical aspect of UA and TGF-β1. They implied that UA competed with TGF-β1 binding to its receptor, which occurred along with inhibition of microRNA-21 and MAPK/ERK1/2 signaling pathways [Cardiomyopathy is a medical term for a heterogeneous group of progressive diseases with structural and functional dysfunctions of the heart, usually with improper ventricular hypertrophy or dilatation. There are four major types, but dilated cardiomyopathy is the most common and mainly caused by coronary artery diseases or hypertension in adults. However, the causes of cardiomyopathies are varied, including environmental factors and genetic predispositions . The devecreased ,58. It ind TSP-1 . Thus, dpathways . Pulmonary arterial hypertension (PAH) is a progressive disease characterized by high blood pressure in the pulmonary arteries and right ventricle remodeling, ultimately leading to chronic heart failure. As the current treatment of this disorder is far away from adequate, Gao et al. administered UA on PAH-induced right ventricle dysfunction in rats. Ameliorated cardiac hypertrophy, cardiac fibrosis and improved hemodynamic parameters of right ventricle were observed after 4 weeks of UA treatment. The authors suggested that the underlying mechanism was based on the increased expression of PPARα and CPT1b, crucial genes regulating fatty acid metabolism and inhibition of pro-apoptotic factor Bax . The above studies show that treatment of cardiomyocytes with UA influences numerous cell signaling enzymes and simultaneously protects them against hypoxic and fibrotic conditions. Therefore, further research is needed to determine more detailed biochemical connections between UA activity and signaling pathways. The summary of the studies describing UA’s impact on cardiomyocytes in vitro and in vivo is shown in 2S) is produced by cystathionine-λ-lyase (CSE) and cystathionine-β-synthase (CBS). H2S is a multi-tasking factor that plays a key role in vascular homeostasis by maintaining its integrity, relaxation and stimulatory effect on the NO signaling pathway [2S release that activates KATP channels located in vascular smooth muscle cells. Additionally, in silico study supported the hypothesis that UA attaches directly to an allosteric binding site in eNOS and CSE, which stabilizes the quaternary structure of the active sites [Hypertension affects every developed society in the world, and by 2030, the prevalence is estimated to reach 37.3% in the US. Despite the presence of antihypertensive drugs with various mechanisms of action, 47.5% of treated patients still do not achieve therapy goals . Incorre pathway ,64. The  pathway  and incr pathway ,41,51,57 pathway . The UA-ve sites . The in ve sites . HoweverThe abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta that affects mainly male elderly people. Not only male sex is an independent risk factor, but also smoking and high blood pressure. Asymptomatic AAA is mainly managed conservatively, but there are two main types of surgery offered to patients: open surgery or minimally invasive endovascular repair. However, considering the pathogenesis of aneurysms, pharmacological prevention or treatment should be investigated to find a medical therapy which may be effective at reducing the growth rate and rupture rate . PathophA study by Zhai et al. on male mice apoE (−/−) with elevated cholesterol levels showed that treatment with UA not only reduced the incidence of angiotensin II-induced AAA but also decreased mortality. In addition, UA increased continuity of aorta by maintaining stability of elastin and reducing the intensity of VSMCs proliferation. In the same study, using immunohistochemistry allowed the authors to find that UA reduced the production of MMP-2, MMP-9, ADAM17 and phosphor-STAT3 (pSTAT3), which may explain the phenotype changes that occurred .Another mechanism was suggested by Huang C et al., who investigated UA influence on VSMCs of aortic aneurysm. The proliferation and migration of VSMCs were inhibited by UA administration through the miR-16/PTEN/PI3K/AKT/mTOR signaling pathway .Among the ursane-type triterpenoids, UA seems to be the most studied member because of its broad spectrum activity. This review has already presented that UA displays promising therapeutic potential in cardiovascular conditions. However, ursane-type triterpenoids comprise a number of bioactive agents, such as asiatic acid, corosolic acid, 23-hydroxy ursolic acid, pomolic acid, uvaol and others ,76. TheiCentella asiatica, commonly known as Gotu Kola, is widely grown in tropical and subtropical countries. One of the constituents contained in this plant is asiatic acid (AA) with its multiple pharmacological activities in the cardiovascular system . Kamble 1 expression and reversed activity of AMPKα [The leaves of Eriobotrya japonica and Lagerstroemia speciosa, commonly called “Japanese loquat” and “Banaba”, respectively, are abundant in corosolic acid (CA) . Its benof AMPKα . The samof AMPKα . Interesof AMPKα . 23-OHUA can be obtained from the stem bark of Cussonia bancoensis. Its structure is close to asiatic acid, and the only difference is the lack of the hydroxyl group at position C-2 . In this12 receptor [2+ exhaustion, which enhanced the rate of cardiomyocytes relaxation (positive lusitropic effect) [Pomolic acid (PA) isolated from Licania pittieri has also been demonstrated to possess a protective effect on the cardiovascular system. Estrada et al. incubated rat aortic rings with PA and vasoconstrictor agents. They found that PA possibly led to the direct activation of endothelial purinergic P2 receptors and the NO-cGMP signaling pathway, which induced a vasodilator effect . The samreceptor . A study effect) . Further−1). The authors compared the obtained result to the pharmacokinetic data that presented a peak plasma UA concentration of 3404 ng/mL at 4 h after administering the liposomal formulation of UA (98 mg/m−2) via intravenous injection [Ramírez-Rodríguez conducted a double-blind study on 24 patients (30–60 years-old) with metabolic syndrome who were randomized to supplement orally with 150 mg of UA or placebo once a day for 12 weeks. In the group receiving the intervention, 50% of them noted transient remission of metabolic syndrome , whereas in the control group, no one achieved such remission . On the njection . This obnjection ,20,98. Tnjection ,95,96,97Clinical trials are essential steps in evaluating the safety and efficacy of potential therapeutic agents. Extensive preclinical studies have clearly shown that UA is a promising drug candidate for the treatment of many contemporary diseases and allowed moving UA into clinical stage. UA is presently under phase I, and by now, only results of three studies have been published ,100,101.The information presented in this article allows for considering UA and its derivatives as potential drugs in the treatment of CVDs. Concluding from the preclinical in vitro and in vivo studies, UA seems to be a multi-tasking substance that regulates many transcription factors, protein kinases and other molecular agents. The inhibition of the pro-inflammatory NF-κB pathway, diminishment of free radical creation and an anti-apoptotic property may prove to be helpful in slowing down atherosclerosis and cardiac fibrosis developments. UA impacts aneurysm growth and possesses a potential vasorelaxant property that needs to be established in the future studies. However, influence on lipid and glucose metabolism remains inconsistent. It is evident that the therapeutic activity of UA can be improved through modifications at different positions. Fresh novel derivatives may need to be synthesized to increase their solubility, bioavailability and potency. This study shows that UA from natural products and its natural or laboratory-synthesized derivatives may represent important cardio- and vasoprotective medicaments and may be promising therapeutical agents in the management of CVDs. However, additional studies are necessary to verify the efficacy of UA in conditions specified in the review, particularly in humans.


The goal of this article was to do this. The approach was to use published data to describe signaling pathways driven by CO bonding to different ferroproteins and then to collate data that describe NO and H2S signaling pathways that could interact with CO signaling pathways and be important during CO poisoning. Arteriolar smooth muscle cells—endothelial cells located in the coronary and some cerebral circulations—were used as a model to illustrate major signaling pathways driven by CO bonding to different ferroproteins. The results were consistent with the concept that multiple deregulated and interacting NO and H2S signaling pathways can be involved in producing cell injury evoked during acute CO poisoning and that these pathways interact with CO signaling pathways.Major toxic effects of acute carbon monoxide (CO) poisoning result from increases in reactive oxygen species (ROS) and reactive nitrogen species (RNS) producing oxidative stress. The importance of altered nitric oxide (NO) signaling in evoking increases in RNS during CO poisoning has been established. Although there is extensive literature describing NO and hydrogen sulfide (H The importance of altered NO signaling in evoking increases in reactive nitrogen species (RNS) during CO poisoning has been established  poisoning have emphasized increases in reactive oxygen species (ROS) and reactive nitrogen species (RNS) that evoke oxidative stress . Other aablished . Roderiqignaling .2S are involved when M-BFC in these circulations is impaired during CO poisoning . Smooth muscle cells (SMCs) with neighboring endothelial cells (ECs) located in arterioles in the coronary and some cerebral circulations were chosen for this model because there is some available information regarding the FPs that reside within these cells . In addioisoning . With thnto SMCs . A majordilation . M-BFC iignaling .2S signaling pathways. Approaching CO poisoning by considering CO bonding to FPs follows the “surprising” non-reactivity of CO in mammalian tissues , NADPH oxidase (NOX), myoglobin (Mb), endothelial NO synthase (eNOS), catalase and peroxidase, cystathionine ß synthase (CBS), prolyl hydroxylase–hypoxia-induced factor (PHD), heme oxygenase-2 (HO-2), the K+ ion channels described below, and EC monomeric Hb a. These FPs include hemoproteins and proteins that require binding of a prosthetic heme for their functions, or like PHD contain non-heme iron. HO-2 has heme-binding sites  Increaoisoning  is likeloisoning . Brain toisoning . The rapoisoning . NO is aoisoning . Increasning (2S . NO can ormation  which inormation . Uncouplormation . NO can ormation . The relHemoglobin (Hb):In blood: Increases in [COHb] evoke oxyhemoglobin dissociation curve shifts which decrease mean capillary PO2 (PcO2) producing tissue hypoxia  that due to inhibition of its function as an O2 sensor  2 sensor . In addid by H2S . As cited by H2S . In pigld by H2S .Mb: Effects of increased [COMb] are 1) inhibition of Mb-facilitated delivery of O2 to oxidases and oxygenases  decrygenases ; and 3) ygenases .PHD:2 sensor that regulates the transcription factor HIF-1α which, in turn, upregulates multiple genes involved in adapting to hypoxia. This PHD senses hypoxia which results in a decrease in HIF-1 degradation, that is, stabilization of HIF-1α. Although during normoxia low [CO] augmented HIF-1α stabilization  Pathway A: Inhaled CO → ↑ [COHb] → ↑ tissue Pg to FPs . Increasssue PCO .CO → CO binding to COX and/or NOX → ↑ [ROS] → cell injury (ii) Pathways A → B1: ↑ tissue Pl injury .iii) Pathway A → B1: CO activation of xanthine oxidase → ↑ [ROS] → cell injury .iv) Pathways A → B1 → B2 → F: CO binding to COX or NOX → ↑ (deregulated) [ROS] → impaired M–BFC → regional tissue hypoxia .2 sensing → impaired M–BFC → regional hypoxia (v) Pathways A → F: CO inhibition of HO-2 O hypoxia .ATP, BKCa, Kv1.5 channels → impaired M-BFC (vi) Pathways A → F: CO effects on Ked M-BFC . CO inhied M-BFC .vii) Pathways A → C → last segment of B1: CO binding to catalases and peroxidases inhibits these enzymes → ↑ [ROS] → cell injury .viii) Pathways A → C → last segment of B1: CO inhibition of HO-2 → ↓ biliverdin/bilirubin formation and biliverdin reductase-evoked scavenging of ROS → ↑ [ROS] → cell injury .ix) Pathways A → H: CO-evoked ↓ HO-2 activity → ↓ heme scavenging → ↑ free heme → cell injury . In addix) Pathways A → I: CO binding to Mb → ↑ COMb → tissue hypoxia .2 sensing function → tissue hypoxia (xi) Pathways A → J: CO binding to PHD → ↓ hypoxia activation that is, loss of its O hypoxia .2 → global tissue hypoxia and possibly regional hypoxia (xii) Pathways A → B1 → B2 → J: ↑ in mitochondrial- and NOX-generated [ROS] → ↓ the ability of PHD to sense PO hypoxia .2 → tissue hypoxia (xiii) The first segment of pathway A followed by Pathway K: ↑ [COHb] → ↓ mean capillary PO hypoxia . Not sho hypoxia .xiv) Pathway L: Cellular hypoxia evokes ↑ CO binding to unidentified FPs which could facilitate other pathways driven by CO binding to FPs .xv) Pathways A → D1: CO displaces NO from its binding to FPs → ↑ [NO] . Normal a → ↑ [NO] (xvi) Pathways A → D1: CO increases NO transport from EC to SMC via binding to the ferrous oxidative state of EC monomeric Hb → ↑ [NO] . (This cxvii) Pathways A → B1 → ROS + NO → E: [NO] + ↑ ROS → ↑ [RNS] → cell injury. . NO, a f2S] → cell injury due to a ↓ in its antioxidant action and ↓ H2S scavenging of ROS → ↑ [ROS] (xviii) Pathways A → G1 → G3 → G2 and B1: CO binding to CBS → ↓ [H ↑ [ROS] .2S] (2S] are outlined before.xix) Pathways A → D1 → D2 → G1: ↑ [NO] → ↓ CBS → ↓ [H2S] . Possiblxx) Pathways A → D1 → D2 → C → the last segment of B1: ↑ [NO] → ↓ HO-2 activity → ↓ biliverdin/bilirubin ROS scavenging → ↑ [ROS] and ↓ heme scavenging . This paxxi) Pathways A → D1 → D2 → F: ↑ or deregulated [NO] → impaired M-BFC → regional tissue hypoxia .2S binding to COX → ↑ [ROS] (xxii) Pathways A → G1 → G3 → B1: ↓ H ↑ [ROS] .2S] → ↑ [NO] → ↑ [RNS] (xxiii) Pathways A → G1 → G3 → D1 → E → ↑ [RNS]: ↓ [H ↑ [RNS] .2S] → impaired M–BFC (2S] are described before.xxiv) Pathways A → G1 → G3 → F: CO bonding to CBS → ↓ [Hed M–BFC . Other pxxv) Pathways A → D1: CO binding to Mb → ↑ [COMb] → ↓ Mb NO scavenging → ↑ [NO]  → delete2-sensing → global or regional tissue hypoxia (xxvi) Pathways A → D1 → D2 → J: ↑ [NO] → loss of PHD O hypoxia .2S signaling could interact with CO signaling pathways and be a factor in CO poisoning-evoked cellular injury. The approach of describing CO poisoning from the viewpoint of CO binding to FPs that exerts control of various signaling pathways illustrates the spectra of different CO targets considered in this article. For this analysis, a vascular model was used to illustrate major signaling pathways driven by CO bonding to different FPs. Other cells contain many of the same FPs. Thus, some of the possible NO and H2S signaling pathways and interactions with CO signaling pathways described using this model are projected to be valid for other cell types. As indicated in the introduction, the importance of CO binding to many of the FPs considered in this article as a function of different levels of CO poisoning is not known.Using published data, the question is asked if NO and H2S formation, impairment of M-BFC, inhibition of O2 sensing by PHD, inhibition of HO-2 free heme and ROS scavenging, and inhibition of catalase. Several reactions are described that could exert positive feedback effects on NO formation during CO poisoning  augmenting Pathway xv evoked increased [NO]. This article also emphasizes possible CO poisoning-evoked changes in H2S signaling where effects of a decreased [H2S] include impaired ROS scavenging and suppression of its function as an antioxidant, and impaired M-BFC. Possible interactions between NO, H2S, and CO signaling that could be important during CO poisoning are described. These include that both CO and NO bonding with CBS can inhibit H2S formation; that a decreased [H2S] can augment [NO] increases; that both increased PCO and increased [NO] (as well as increased [ROS] and [RNS]) can impair the PHD function as an O2 sensor; that both increased PCO-evoked [H2S] decreases and [NO] changes can impair M-BFC; that NO and CO can inhibit catalase activity; and that NO and H2S as well as CO can inhibit HO-2 activity. Cited data indicate interactions between H2S, NO, and ROS signaling. These include that both H2S and NO can be involved in mediating [ROS] or [RNS]. ROS targets considered in this article include PHD and multiple ion channels involved in M–BFC. Thus, it is suggested that alterations in NO and H2S signaling during CO poisoning scenarios may occur in tandem with deregulation of ROS signaling. Findings also suggest that normal NO and H2S signaling pathways, like normal endogenous CO signaling, may be deregulated during CO poisoning. This would not just be a result of changes in bioactivities of the gaso-transmitters described before. Precise signaling at various cellular and subcellular targets is likely lost as is well recognized to occur during increased PCO-evoked redox signaling. Whether deregulated NO and H2S signaling could contribute to cell injury occurring during different levels of CO poisoning is another issue. An argument supporting this hypothesis is that multiple deregulated and interacting NO and H2S signaling pathways are likely to be involved in producing or mediating cell injury evoked during CO poisoning because these pathways can potentially interact with CO signaling pathways that trigger cell injury.In this article, the well-known effects of increased [NO] that occur during CO poisoning, described in pathways xv and xvii, were expanded to include NO-evoked inhibition of CBS-evoked H2S signaling pathways as effectors of cell injury during CO poisoning scenarios. It is not possible yet to describe a mechanistic continuum of the different pathways. It seems possible that cell injury resulting from different severities or time durations of CO poisoning involves different segments of a signaling network. However, because of a lack of NO and H2S binding and bioactivity information, it is not established that any of the NO pathways described before, other than those shown in pathways xv and xvii, nor any of the H2S pathways, operate in the SMC-EC model during CO poisoning. A weakness in the approach used in constructing the pathways shown in the Figure is that data taken from published results were obtained using different types of cells, and none of them include arteriolar SMC-ECs. In addition, the discussion of H2S pathways does not consider that metabolic pathways other than CBS can form H2S, or effects on H2S degradation during CO poisoning. There are also issues related to subcellular locations where H2S is formed. It is not clear how multiple downstream H2S reactions could influence [H2S]-dependent mechanisms described in this article. A major emphasis in this article is on H2S functions as an antioxidant and ROS scavenger during oxidative stress and its role in M-BFC. For NO, this article only considers reactions related to CO poisoning, on top of large literature describing multiple functions of NO signaling. However, even considering these caveats, it seems justified to conclude that listing and describing possible NO and H2S signaling pathways as described in this study is a step forward toward understanding how signaling of these gaso-transmitters could function during acute CO poisoning scenarios. More research is necessary to better delineate the importance and details of deregulated NO signaling and H2S signaling during CO poisoning-evoked cell injury. As stated before, more binding and NO and H2S bioactivity data are needed. The importance of specific FP CO targets in generating signaling also depends on their CO binding constants, and a challenge for future research is to determine these constants and the extent of CO bonding to different FPs at different PCO. There are calculated data that suggest that tissue PCO in resting humans could increase 50- to 60-fold as the [COHb] increases from normal to 40% saturation  This study explores how multiple NO and H2S signaling pathways interact with deregulated CO and ROS signaling pathways.ii) Results are consistent with the hypothesis that during acute CO poisoning scenarios, multiple deregulated and interacting NO and H


The heart is comprised of multiple tissues that contribute to its physiological functions. During development, the growth of myocardium and endocardium is coupled and morphogenetic processes within these separate tissue layers are integrated. Here, we discuss the roles of mechanosensitive Hippo signaling in growth and morphogenesis of the zebrafish heart. Hippo signaling is involved in defining numbers of cardiac progenitor cells derived from the secondary heart field, in restricting the growth of the epicardium, and in guiding trabeculation and outflow tract formation. Recent work also shows that myocardial chamber dimensions serve as a blueprint for Hippo signaling-dependent growth of the endocardium. Evidently, Hippo pathway components act at the crossroads of various signaling pathways involved in embryonic zebrafish heart development. Elucidating how biomechanical Hippo signaling guides heart morphogenesis has direct implications for our understanding of cardiac physiology and pathophysiology. The Hippo signaling pathway is a key regulator of organ size and cell proliferation  in respoSnail, Slug, and Twist1   and cellA recent study addressed the role of Yap1 during endocardial chamber expansion. Using a laser-dissection approach , the autWhile this work suggests some mode of intra-organ communication by which myocardial expansion is transmitted to the endocardium, the precise mechanism of that crosstalk has largely remained unexplored. Endocardium and myocardium are connected by extracellular matrix (cardiac jelly), which may propagate mechanical tension between these tissues [reviewed in piezo1 or trpp2 mutants, Klf2a reporter expression became activated in anterior and posterior regions of the valve endothelium, suggesting these channels inhibit klf2a expression in that tissue. Piezo1 also impacted the nuclear localization of Yap1 within the neighboring vascular smooth muscle cell layer. Since klf2a mutants have normal Yap1 localization and expression, this effect may be attributed directly to Piezo1, which is expressed at low levels also within the smooth muscle cell layer. Hence, Piezo1 apparently has two roles during OFT valve formation by regulating klf2a expression within the endothelium, and Yap1 localization during smooth muscle cell maturation. This is yet another example for the complexity of Hippo pathway activity within the multi-tissue comprising heart. These findings add Piezo1 to the repertoire of mechanosensitive modulators of Hippo signaling during cardiac valve formation in zebrafish , lacking all primary cilia, had reduced epicardial cell numbers. The authors discovered that a loss of Ift88 causes increased proepicardial bmp4 expression and Hippo signaling. In an elegant pharmacological suppression study, the authors found that blocking the interaction between Yap1 and Tead (using the drug Verteporfin)  activity in human fibroblast, rat, and mouse cell lines  , suppresll lines . Furtherll lines . Given tRecent studies have significantly expanded our understanding of mechanosensitive Hippo signaling during zebrafish cardiac development. Currently, a complex picture has emerged of cell-intrinsic and -extrinsic cues that modulate this biomechanical signaling pathway. Likewise, our knowledge of the repertoire of developmental roles of the Hippo effectors Yap1/Wwtr1 and their crosstalk with other pathways is steadily increasing. Biomechanical forces that can impact Hippo signaling include hemodynamics, cell stretching, cellular crowding/tension, junctional forces, mechanical coupling, and actomyosin cytoskeletal rearrangements . Upon meStudies in the developing zebrafish heart revealed that Hippo signaling in one tissue layer can be affected by the development of other cardiac tissues. Such a form of intra-organ communication between myocardium and endocardium was observed when an expansion of myocardial atrial chamber dimensions triggered increased endocardial cell proliferation . Increasklf2a activities and affect Yap1 activation (The AVC and OFT valves are composed of specialized endothelial/endocardial cell types, each with different cellular responses in the context of biomechanical Hippo signaling. Within OFT endothelial cells, Piezo1/2 channels control Notch and tivation . Whethertivation . Howevertivation  or OFT etivation . CurrentMultiple studies indicated blood flow as a key player during trabeculation and myocardial wall maturation . In the It is very likely that Hippo pathway signaling is also regulated by biomechanical stimuli during cardiac development of higher vertebrates. The pioneering studies in zebrafish have been facilitated by the ease with which blood flow and cardiac contractions can be modulated in that model organism. It will be an exciting but far more challenging approach to elucidate whether Hippo pathway-dependent cellular and molecular biomechanical processes play roles during the development or physiology of the mammalian four-chambered heart. For instance, recent evidence suggests that changes to cardiomyocyte cytoskeleton, cell junctions, and extracellular matrix composition impact YAP nuclear localization and heart regenerative capacity in mice . OverallDB designed the figures and wrote the first draft. DB and SA-S revised, wrote, and edited the final manuscript. Both authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


There was a strong correlation between HTLV-1 PVL, anti-HTLV-1/2 IgG BR, and titer when comparing milk and blood. PVL did not correlate with antibody BR nor titer in blood or milk. Conclusions: Anti-HTLV-1/2 IgG are present in milk in the same proportion as blood but in lower quantity. PVL in milk correlates with blood.Background: HTLV-1/2 mother-to-child transmission (MTCT) is an important route for the maintenance of HTLV-1/2 within populations and disproportionally contributes to the burden of HTLV-1-associated diseases. Avoidance of breastfeeding is the safest recommendation to prevent MTCT. Due to the benefits of breastfeeding, alternative methods that would allow seropositive mothers to breastfeed their babies are needed. There is limited knowledge about HTLV-1/2 infection and breastmilk. Methods: Paired blood and milk samples collected from HTLV-1/2 seropositive mothers were tested for HTLV-1 proviral load (PVL) quantification and for the detection of anti-HTLV-1/2 IgG. Results: All breastmilk samples had detectable anti-HTLV-1/2 IgG. HTLV-1/2 proviral DNA was detected in all samples except for one. HTLV-1 PVL and IgG binding ratio (BR) was similar in milk and plasma. However, antibody titer was significantly higher in blood (Median (95%CI): Milk:128 (32–512); Plasma:131,584 ,  Human T-cell lymphotropic virus (HTLV) infects at least 5–10 million individuals in the world  and thisIn HTLV mother-to-child transmission (MTCT), infected lymphocytes carrying integrated HTLV-1 proviruses are transferred from mother to child either in utero, during delivery, or through the transfer of infected cells during breast feeding . Ante-naThe main recommendation to avoid MTCT is the suspension of breastfeeding and provision of formula milk to those babies born from seropositive mothers . HoweverPrevious studies have not detected anti-HTLV-1 antibodies in milk ,8,9. HerNine paired breastmilk and EDTA blood samples were collected from seven women with HTLV-1/2 asymptomatic infection attending the National Centre for Human Retrovirology, London, UK during post-natal follow-up. One was infected by HTLV-2 and six with HTLV-1. One woman had samples available from post-partum periods of two pregnancies and another woman donated samples in two different time points after a single delivery. An additional pair of samples obtained from a woman not infected by HTLV-1 was included as a negative control. Plasma and peripheral blood mononuclear cells (PBMCs) were separated by Ficoll density gradient centrifugation. Breastmilk samples were collected by manual expression and cells were obtained by centrifugation. HTLV proviral load (PVL) was quantified in peripheral blood mononuclear cells (PBMCs) and breastmilk cells by real-time PCR , while pAnti-HTLV-1/2 antibodies were detected using the anti-IgG capture immune assay, as previously described . BrieflyWilcoxon paired test was used to compare IgG BR, IgG titer, and HTLV PVL between plasma and breastmilk samples. The correlation between variables  in plasma and breastmilk was assessed using Spearman’s test. The same test was used to identify if the BR and antibody titer correlated to HTLV-1 PVL.All samples were donated to the Communicable Diseases Research Group Tissue Bank  after participants had provided written informed consent.p > 0.05). However, the antibody titer was significantly higher in blood (Median (95%CI): Milk:128 (32–512); Plasma:131,584  (All breastmilk samples had detectable anti-HTLV-1/2 IgG. There was no significant difference between the BR of anti-HTLV-1/2 IgG between blood plasma and breast milk supernatant (Median (95%CI): Milk: 5.9 (2.5–16.6); Plasma: 5.7 (2.8–14.4), 131,584) B, C. Ant131,584) .p = 0.625)  A.There was a perfect correlation between HTLV-1 proviral load in milk and PBMC D. A stroAnti-HTLV-1/2 IgG BR correlated with antibody titer A,B. The The only patient who had samples collected after two pregnancies had comparable results, as well as the patient who had samples available from two different time points after delivery .Understanding the mechanism behind mother-to-child transmission and protection is essential to develop alternatives to prevent vertical transmission of HTLV-1/2 and the burden of the diseases associated with this virus. This study showed that anti-HTLV-1/2 IgG was present in the milk of seropositive mothers. As IgG capture assay is a proportionality assay: its BR is associated with the proportion of target antibodies in the tested sample, rather than in their quantity . AlthougOur group showed previously that pregnant women infected by HTLV-1 had a discrete but statistically significant increase in anti-HTLV-1/2 antibody levels during pregnancy  and, altIn the two sequential samples included in this study, the titer of antibodies and PVL were very consistent. Whilst is difficult to extrapolate data on two cases to all lactating HTLV-1 infected mothers, these data did suggest that the quantity of antibodies and PVL may be stable during the post-partum period. Our group previously demonstrated the stability of HTLV proviral load, within individuals who were neither pregnant nor lactating, in established infection, over a median of eight years follow-up .The detection of IgG in milk may be useful for the screening of donors in milk banks. A previous study showed the detection of antibody in milk donors; however, the HTLV-1/2 serostatus was unknown . HTLV scThis study also confirmed that there is a strong correlation between HTLV-1/2 PVL in blood and milk . This inThis study had some limitations such as the small number of samples, the fact that all patients had asymptomatic infection, and most of them were breastfeeding for a short period due to the local recommendation for seropositive mothers to avoid or limit short-term breastfeeding.Strongyloides sp. co-infection; and access to safe, affordable formula feeding. A recent meta-analysis showed that short-term breastfeeding was not associated with a significant increase in the transmission of HTLV-1 [For those who wish to breastfeed, the risk versus benefit should be balanced on an individual basis, considering: the viral type, as HTLV-2 is less pathogenic than HTLV-1; risk factors that may contribute to MTCT, such as HTLV-1/2 PVL and the presence of f HTLV-1 . Howeverf HTLV-1 . Freeze-f HTLV-1 ,23. Alth


Escherichia coli O157:H7. At greater than 200 MPa, PCA (1.25 mg/mL for 60 min) plus HHP treatments had significant synergetic bactericidal effects that positively correlated with pressure. After a combined treatment at 500 MPa for 5 min, an approximate 9.0 log CFU/mL colony decline occurred, whereas the individual HHP and PCA treatments caused 4.48 and 1.06 log CFU/mL colony decreases, respectively. Mechanistically, membrane integrity and morphology were damaged, and the permeability increased when E. coli O157: H7 was exposed to the synergetic stress of PCA plus HHP. Inside cells, the synergetic treatment additionally targeted the activities of enzymes such as superoxide dismutase, catalase and ATPase, which were inhibited significantly (p ≤ 0.05) when exposed to high pressure. Moreover, an analysis of circular dichroism spectra indicated that the synergetic treatment caused a change in DNA structure, which was expressed as the redshift of the characteristic absorption peak. Thus, the synergetic treatment of PCA plus HHP may be used as a decontamination method owing to the good bactericidal effects on multiple targets.With the wide application of high hydrostatic pressure (HHP) technology in the food industry, safety issues regarding food products, resulting in potential food safety hazards, have arisen. To address such problems, this study explored the synergetic bactericidal effects and mechanisms of protocatechuic acid (PCA) and HHP against  Escherichia coli O157:H7 is a harmful and common foodborne pathogenic bacteria that causes life-threatening infectious diseases [Escherichia coli O157:H7 adapts to environmental and processing stresses [Outbreaks caused by foodborne pathogens have received public and media attention because of their risks to consumers. diseases . Escheristresses , which mstresses . TherefoWith the increasing consumer demand for fresh food, having an improved nutritional quality, several non-thermal treatments have been introduced . Among tStaphylococcus aureus, Escherichia coli and Listeria monocytogenes, might be attributed to the disruption of cell membranes and the subsequent increase in membrane permeability [E. coli adhesion and biofilm formation [2 has strong bactericidal effects on Staphylococcus aureus and E. coli [Protocatechuic acid  is a water-soluble natural product that exists widely in edible plants, fruits and vegetables . Its anteability ,17,18. Bormation . Additioormation ,20. Cons E. coli . Nassau  E. coli  also fouThe objectives of this study were to investigate comprehensively the bactericidal effects and mechanisms, including those related to membranes, intracellular macromolecules, enzyme activities and morphology. The current study provides a way to offset HHP’s bactericidal effect-related deficiency, and explores PCA’s potential as a food additive.+) assay kit, magnesium (Mg2+) assay kit, superoxide dismutase (SOD) assay kit (WST-1 method), catalase (CAT) assay kit (visible light), and minim adenosine triphosphate enzyme (ATPase) test kit were all purchased from Jiancheng Bioengineering Institute . The bis- trimethine oxonol (DiBAC (4)3) dye and phosphate buffer  were purchased from UE Everbright Incorporation  and Biotopped Co., Ltd. , respectively.Protocatechuic acid  and propidium iodide  were purchased from Solarbio life sciences, Co., Ltd. . Ampicillin (1 mg/mL) and glutaraldehyde fixative (2.5%) were purchased from BioDee Biotechnology Co., Ltd. . The Bradford kit, potassium (KThe nutrient broth culture medium (NB) and tryptose soya broth culture medium (TSB) was purchased from Aoboxing Biotech Co., Ltd. . The tryptose soya ager (TSA) was purchased from Qingdao Hope Bio-Technology Co., Ltd. .E. coli O157:H7 NCTC 12900 strain, was purchased from the China Center of Industrial Culture Collection  and stored at −20 °C. The strain was activated by incubating in NB at 37 °C for 7 h and then transferred to NB supplemented with 20% agar powder slant cultures and stored at 4 °C. After streak culturing in TSA, a loop of a single colony was then transferred to 50 mL TSB (pH 7.2), incubated in a shaker  at 37 °C, 180 rpm for 6 h until the culture reached the middle period of logarithmic phase [8–109 colony forming units per milliliter (CFU/mL).The ic phase . The bacE. coli O157:H7 was determined in accordance with Shi et al. [The minimum inhibitory concentration (MIC) of PCA against i et al.  with slii et al. . Afterwa8–109 CFU/mL.The study had two experimental groups, the HHP and synergetic (PCA + HHP) treatment groups. In the HHP group, 10 mL bacterial suspension was packaged per aseptic sealed bag, and then, the bags were treated independently with 0, 100, 200, 300, 400 and 500 MPa for 5 min at 25 °C using HHP equipment . The rise (approximately 2–3 min) and relief (approximately 1–2 s) times were not included in the processing time. In the PCA + HHP group, the samples were pre-treated with a 1/2-MIC PCA aqueous solution . The pellets were each re-suspended in 10 mL 1/2-MIC PCA solution, and then cultured at 37 °C for 60 min at 120 rpm. The bacterial suspension after the PCA treatment was then treated under the same conditions as the HHP group . For the7–108 CFU/mL), and then incubated at room temperature for 30 min in the dark. The mixture was washed two times with PBS buffer to remove excess dye by centrifugation at 6000 rpm and 4 °C for 10 min). The pellet was resuspended in 1 mL PBS for flow cytometry detection . The excitation wavelength was 488 nm, and a total of 50,000 cells were detected.Membrane permeability was determined using the PI staining method in accordance with Raffellini et al. . Briefly260 nm using a UV-vis spectrophotometer in accordance with previous research [+ and Mg2+ concentrations were determined using potassium [2+ concentration, the samples were mixed 1:4 with the complexation indicator calmagite. After 1 to 2 min of incubation at 37 °C, the absorbance was measured at 540 nm. The K+ concentration was obtained by mixing samples at a 1:4 ratio with sodium tetraphenylborate and determining the absorbance at 440 nm. To avoid the influence of K+ and Mg2+ ions in PBS, each pellet was washed and re-suspended in 0.85% NaCl solution instead of PBS. The initial concentration of the bacterial suspension was approximately 108–109 CFU/mL.The bacterial suspensions subjected to different treatment were centrifuged by 6000 rpm and 4 °C for 10 min. Each pellet was re-suspended in PBS and then crushed using an ultrasonic processor  in an ice bath to obtain the intracellular solution. The concentration of the intracellular protein was determined using a Bradford kit, which involved mixing the intracellular solution and Coomassie brilliant blue stock solution in a ratio of 1:60 to determine the absorbance at 595 nm using an UV-vis spectrophotometer . The final concentration was determined by comparing and converting the absorbance with that of the standard protein solution . The intracellular nucleic acid content was determined at ODresearch  with modotassium  and magnotassium , respect3 dye was used to determine the change in membrane potential in accordance with Nuding et al. [3 solution  was added to 1 mL 10× diluted bacterial suspension (approximately 107–108 CFU/mL concentration). The mixture was shaken to mix thoroughly, and then incubated at room temperature for 30 min in the dark. Flow cytometry detection was used to observe the fluorescence intensity, and the excitation wavelength was 517 nm.DiBAC(4)g et al. . BrieflyX and A0 represented the enzyme activities of samples exposed to different treatments (X) and the untreated sample, respectively.The activities of intracellular oxidative stress-related SOD and CAT were determined using the SOD and CAT assay kits, respectively . The exp+ K+-ATPase, Ca2+ Mg2+-ATPase and total-ATPase activities using a Minim ATP enzyme test kit. The pellet was suspended in cold sterile water and then ultrasonicated to obtained the enzyme solution. The finally result was measured at 636 nm, and the unit of ATPase activity was U/mg protein.The intracellular solution, described previously (in 0.85% NaCl solution) was used to determine the NaIntracellular protein and nucleic acid structures were determined using CD spectra  using the intracellular solution described in E. coli O157:H7 after different treatments. Bacterial suspensions of the HHP and PCA + HHP groups were prepared as described in AFM was performed to observe the morphological changes of t-tests. The Duncan and t-tests were both carried out using SPSS software . p ≤ 0.05 was considered statistically significant.All the experiments were performed in triplicate to confirm data credibility. Data were presented as the mean values ± standard deviations. The differences within groups were processed using a one-way analysis of variance, followed by Duncan’s tests, a method used for comparing the differences between multiple samples. The differences between groups were determined by E. coli O157:H7 was 2.5 mg/mL, which was same in Nuding et al. [p = 0.474) after 60- and 75-min treatment times. Consequently, the PCA treatment conditions were determined as 1.25 mg/mL (1/2 MIC) and 60 min.The MIC of the PCA on g et al. . To ensug et al. . TherefoE. coli O157:H7 populations after no, single PCA, HHP and PCA + HHP treatments are shown in E. coli O157:H7 was approximately 9.0 log CFU/mL. As the pressure increased, the surviving colony populations decreased in both the HHP and PCA + HHP groups. In the HHP group, the colony population started to decrease significantly when the pressure reached 300 MPa. When the pressure reached a maximum (500 MPa for 5 min), there were 4.48 log CFU/mL of colonies reduced, which was similar to the findings of Arbol et al. [E. coli O157 strain was reduced 5.36 log CFU/mL after 500 MPa for 8 min. The number of surviving colonies was reduced considerably by 1.07 log CFU/mL after the single PCA treatment. After the combined PCA + HHP treatment, the surviving colonies kept significantly decreasing with every 100-MPa increase in pressure, which could result from the difference of the pH value in the solution HHP and PCA + HHP treatments, or the PCA treatment affecting the tolerance of the membrane to HHP [The surviving l et al. , in whice to HHP . When trCronobacter sakazakii membrane permeability was discovered by Jia et al. [PI is a nucleotide-binding probe that produces red fluorescence when crossing damaged membranes, and it is commonly used in the determination of membrane permeability. As shown in a et al. . After bp ≤ 0.01) higher than that in the HHP group at pressures greater than 200 MPa. Additionally, the protein content showed no significant change after the pressure reached 300 MPa, nor did the intracellular nucleic acid contents  as the pressure increased. Compared with the HHP group, the intracellular K+ content was lower in the PCA + HHP group. The intracellular Mg2+ content . Shi et al. [katG, which encodes KatG enzyme (a distinct CAT), is up-regulated in E. coli after a lactic acid treatment. After the PCA + HHP treatment, the CAT activity reached a maximum (128.76%) when the pressure reached 200 MPa, and then it decreased to 96.85%. As shown in The CAT activity patterns, as shown in i et al.  found th2+Mg2+-ATPase and Na+K+-ATPase catalyze the hydrolysis of ATP that is coupled to the active transport of Ca2+/Mg2+ and Na+/K+, respectively, across the cell membrane, which play essential roles in the transduction of signals, maintenance of cell homeostasis and decomposition and synthesis of ATP [+K+-ATPase, Ca2+Mg2+-ATPase and total-ATPase are shown in Listeria monocytogenes. In the PCA + HHP group, the Na+K+-ATPase, Ca2+Mg2+-ATPase and total-ATPase activities rapidly decreased to approximately 1/6, 1/5 and 1/4 of the initial concentrations after the PCA only pre-treatment, respectively. They then decreased slightly as the pressure increased.Cas of ATP ,43. The 3, an anionic lipophilic dye that enters only depolarized cells and then fluoresces by binding reversibly to the hydrophobic core of the lipid membrane [The membrane potential was determined using DiBAC(4)membrane . The meamembrane . As showThe structures of intracellular proteins and nucleic acids were determined using CD spectroscopy. As shown in The CD spectroscopy of the nucleic acid structure is shown in E. coli O157:H7 cells captured in water using the tapping mode are shown in E. coli O157:H7 membrane damage observed by SEM was induced by the combination of low-intensity ultrasound and propyl gallate. In addition to the morphological observations, the roughness of the cell membrane is an important cytological parameter mainly obtained using the AFM technique and it is also a sensitive indicator of the cell’s health [The AFM height images of s health . As showThis research studied the bactericidal effects and mechanisms of a new decontamination method, which combined HHP technology with PCA. According to our results, the combination of HHP and PCA produced a synergetic bactericidal effect when the pressure was greater than 200 MPa. When the pressure reached 500 MPa, the number of bacterial colonies was reduced by approximately 9.0 log CFU/mL . AccordiThe impacts of HHP and PCA + HHP on membranes were assessed by investigating membrane permeability, intracellular constituent contents, membrane potentials and morphological changes. The PCA treatment itself increased membrane permeability, perhaps because the hydrophobic -OH structure of PCA bound to the lipid bilayer of the membrane, thereby changing the membrane’s structure . Notably+ and Mg2+ contents all showed downward trends, indicating that the leakage of intracellular constituents was induced by the increase in membrane permeability. However, the protein and nucleic acid leakage in the PCA + HHP group was less than that of HHP group . The K+ and Mg2+ leakage levels, of the PCA + HHP group, were higher than those of the HHP group , intracellular macromolecule structures, morphology and intracellular substances contents . More specifically, the HHP treatment mainly destroyed the cell membrane, whereas the combined PCA + HHP treatment also significantly affected nucleic acid structures and membrane-associated enzyme activities. The results that suggested the synergetic PCA + HHP treatment could be used as a new bactericide owing to the treatment’s good bactericidal effects and multiple targets. In addition, PCA has the potential to become a food additive owing to its multiple targets.Against


Breast cancer (BC) is now the leading cause of cancer in women, and bone is the primary site of distant BC metastasis. BC bone metastasis seriously affects the quality of life of patients and increases the mortality rate. However, the mechanism of BC bone metastasis is not fully understood.Paget’s “seed and soil” hypothesis led experts to explore the relationship between surface markers and receptors in breast tumors and various growth factors in bone. The relevant breast tumor markers serve as “seeds”, and the bone microenvironment that is suitable for the survival of the tumor serves as the “soil”. These factors interact to make up an entire system and form feedback pathways that accelerate the production of various cytokines, attracting BC cells to migrate to bone tissue, which worsens the development of BC and seriously affects the prognosis of patients. This process is a vicious cycle. At present, there are seven major signaling pathways involved in BC bone metastasis: the OPG/RANK/RANKL signaling pathway, TGF-β signaling pathway, IGF system, PI3K-AKT-mTOR signaling pathway, Wnt signaling pathway and Hippo signaling pathway. In addition, FGF-FGFR signaling pathway, androgen-AR/LSD1-target gene pathway, Notch signaling pathway, JAK-STAT signaling pathway and CaN/NFATC1 signaling pathway also seem to be associated with BC bone metastasis.This review focuses on the signaling pathways related to BC bone metastasis and explores the interactions among these pathways, which will lay a solid theoretical foundation for further understanding the mechanism of BC bone metastasis and developing effective targeted therapeutic drugs. BC metastasis to bone further promotes the release of bone growth factors and cytokines, accelerating the growth and development of tumor cells, resulting in a vicious cycle. In summary, this review focuses on the signaling pathways related to BC bone metastasis and explores the interactions among these pathways, which will lay a solid theoretical foundation for further understanding the mechanism of BC bone metastasis and developing effective targeted therapeutic drugs.Presently, breast cancer (BC) is the most common malignant tumor and the most important health burden, as well as the most common cause of cancer death among women worldwide. Recently, statistics have shown that the incidence of BC in various countries around the world is increasing at an accelerated rate, and the affected population is becoming younger . With thLangenbeck once said that “Every cancer cell must be viewed as a living organism capable of development. When plants seed, the seeds are carried in all directions, but they only can survive and grow if they land in the right soil.” In 1882, Fuchs argued that certain organs might be susceptible to secondary cancer. In 1889, Stephen Paget proposed the “seed and soil” hypothesis, which held that tumor cells (seeds) could only grow in fertile soil (bone microenvironment). He argued that in BC, bones suffer in a way that no embolic theory alone could explain . HoweverSoil can be defined as a bone microenvironment, containing many cellular growth factors which are the essential factors for growth and metastasis of BC cells Figure 1Seeds can be defined as the surface markers, which are the identifiable factors, of breast tumor cells Figure 1via the blood to the bone marrow space  and Jun N-terminal kinase (JNK) signaling pathways, leading to bone resorption. However, excessive absorption can be stopped by osteoprotegerin . In solivia membrane-bound, heteromeric, serine-threonine kinase receptor complexes, whose activation by TGF-β ligands leads to phosphorylation of proteins of the SMAD family  family members signal D family Figure 3chanisms , 48. Of chanisms . TGF-β ichanisms  or SMAD7chanisms  in breaschanisms , 53 was TGF-β signaling forms a feedback pathway in the occurrence and development of BC, accelerates the progression and metastasis of breast tumors, and participates in the regulation of other pathways to amplify tumor effects . First, In breast tissue, the basic function of IGF is to promote cell proliferation and differentiation through endocrine, paracrine and autocrine mechanisms, and IGF has an antiapoptotic effect. In fact, IGF acts not only on normal cells but also on tumor cells . IGF is In primary tumors, a high level of IGF-1 in the environment can promote tumor cell metastasis to bone, suggesting that BC bone metastasis may be IGF-dependent . In addiin situ but may be effective in patients with BC bone metastases.Currently, there are many tumor treatments based on IGF, such as blocking the synthesis and secretion of IGF-1, blocking the binding of IGF-1 to its receptor, downregulating IGF-1, downregulating and antagonizing IGF-1R, and blocking receptor activity , 66. Thein vivo and in vitro. In addition, inhibition of the PI3K-AKT-mTOR signaling pathway can suppress breast cancer growth and breast cancer-induced osteoclast formation (The phosphoinositide 3-kinase (PI3K)-AKT-mTOR signal transduction pathway is present in a variety of cells in the body and participates in various physiological processes, such as cell metabolism, mitosis, and cell differentiation. This pathway is also one of the most common signaling pathways in a variety of cancers, regulating tumor cell proliferation, apoptosis, invasion and metastasis   -protein kinase C (PKC) signaling pathways -mediated, synergistic increase in proliferation of breast cancer cells and mesenchymal stromal cells (MSCs) in co-culture. The stromal induction was associated with elevated phosphoinositide-3 kinase (PI3K) signaling in the stroma, which coupled with elevated bFGF levels resulted in increased migration of breast cancer cells towards the MSCs. The perturbed cytokine profile in the stroma led to reduction in the osteogenic differentiation of MSCs PDGF-BB) . FGF andPDGF-BB) . Wnt sigPDGF-BB) . In addiPDGF-BB) , 100 andPDGF-BB) , 102. FGpathways . Among tpathways . Therefopathways .Interesting, it has been found that applied mechanical tension can dramatically alter gene expression in breast cancer cells, leading to decreased proliferation, increased resistance to chemotherapeutic treatment and enhanced adhesion to inflamed endothelial cells and collagen I under fluidic shear stress. A mechanistic analysis of the pathways involved in these effects supported a complex signaling network that included Abl1, Lck, Jak2 and PI3K to regulate pro-survival signaling and enhancement of adhesion under flow. Studies using mouse xenograft models demonstrated reduced proliferation of breast cancer cells with orthotopic implantation and increased metastasis to the bones when the cancer cells were treated with mechanical load . FurtherIn short, signaling pathways interact with each other to promote the development of BC bone metastasis. The secretion of various growth factors creates a vicious cycle, amplifying the signals associated with BC bone metastasis and promoting “seed” germination in the “soil”. It is not enough to understand the soil and seeds alone, and we should also increase efforts to thoroughly understand the various signaling pathways and their potential relationships. This understanding can truly prevent BC bone metastasis and lay a solid foundation for future treatment to relieve the pain and prolong the life of BC patients with bone metastases.XS wrote this manuscript. XS and CW drew the pictures in this paper. In addition, XS, CW, and XL revised the manuscript. All authors contributed to the article and approved the submitted version.The present study was supported by the National Natural Science Foundation of China (grant no. 81473687), the Academic Promotion Program of Shandong First Medical University (grant no. 2019QL017), the Natural Science Foundation of Shandong Province , Tai’an Science and Technology Innovation Development Project (grant no.2020NS092).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.