Rapid progress in nanotechnology has advanced fundamental neuroscience and innovative treatment using combined diagnostic and therapeutic applications. The atomic scale tunability of nanomaterials, which can interact with biological systems, has attracted interest in emerging multidisciplinary fields. Graphene, a two-dimensional nanocarbon, has gained increasing attention in neuroscience due to its unique honeycomb structure and functional properties. Hydrophobic planar sheets of graphene can be effectively loaded with aromatic molecules to produce a defect-free and stable dispersion. The optical and thermal properties of graphene make it suitable for biosensing and bioimaging applications. In addition, graphene and its derivatives functionalized with tailored bioactive molecules can cross the blood–brain barrier for drug delivery, substantially improving their biological property. Therefore, graphene-based materials have promising potential for possible application in neuroscience. Herein, we aimed to summarize the important properties of graphene materials required for their application in neuroscience, the interaction between graphene-based materials and various cells in the central and peripheral nervous systems, and their potential clinical applications in recording electrodes, drug delivery, treatment, and as nerve scaffolds for neurological diseases. Finally, we offer insights into the prospects and limitations to aid graphene development in neuroscience research and nanotherapeutics that can be used clinically. This enin vitro because of their physical and chemical properties  materials have been extensively explored for biomedical applications . With suPrevious studies have shown that graphene can aid in the adhesion and differentiation of neurons and can act as a neuroprotective agent. Graphene is a potential carrier to control drug release at specific disease sites, making it a valuable treatment strategy for neuronal diseases. Moreover, graphene and its derivatives can be used as scaffolds to enhance nerve repairing, establishing it as a next-generation candidate for advancing medical bioengineering. However, the safety of nanomaterials is essential to protect human health and ensure environmental safety. Thus, further studies are warranted to fill the knowledge gap on the limitations of carbon nanomaterials, including their toxicity and biocompatibility .In this review, we focus on novel graphene applications in the nervous system. Graphene-based materials may be used clinically in the future; however, this article is limited to pre-clinical applications. We aimed to describe the properties of graphene-based materials applicable in neuroscience research, including using them as electrodes for neural recording and imaging, neural cell substrates, photothermal effects, and drug and gene deliveries. Furthermore, we aimed to outline the application of graphene-based materials in neurological diseases and neural tissue engineering. Finally, we aimed to discuss graphene’s cytotoxicity and provide an overview of its prospects.2.−1, superior to graphene grown on indium tin oxides. Unfortunately, this technique requires a very high temperature and vacuum environment, as well as exorbitant prices for only small-size devices. Many graphene-based nanomaterials are built up mostly by chemical reactions for covalent bonding, such as graphene oxide [GO; Graphene is a sheet comprising a single layer of carbon atoms formed by stripping highly oriented pyrolytic graphite, like carbon nanofibers, another type of nanomaterial. In 2D, sp2 hybridized carbon atoms give graphene a hexagonal honeycomb lattice pattern with a thickness of approximately 0.335 nm [At room temperature, the interactions between carbon atoms in graphene are strong. Electrons in the carbon atoms are not easily affected or scattered by the movement of surrounding carbon atoms; its conductivity also contributes to electron transfer . Additio3.Neural interfaces are typically implanted with electrodes that can record or stimulate target tissues or cells in the brain, thereby establishing connections with the nervous system . Howeverin vivo microscopy techniques performed on freely behaving animals. However, one of the major problems of using graphene in in vivo studies is that it is ultra-flexible and difficult to implant surgically. Graphene can be mechanically deformed beyond the linear regime ; this isin vivo neural recording by graphene electrodes compared to gold electrodes  for recording cellular activity is challenging. Studies have demonstrated effective ectrodes . In thesectrodes . Recentlin vivo recording validation.The mechanical properties, electrical conductivity, and large surface area of graphene make it perfect material for developing ideal neural interfaces and more reliable electrodes, while highlighting the unique advantages of composites, demonstrating greater application potential in neural interfaces. However, more studies are required to investigate the long-term effects of graphene-based nanoelectrodes during 4.Traditional metal electrodes used for recording electrophysiological activities obstruct the vision field, produce optical shadows, and are more likely to introduce light-induced artifacts during the recording. Researchers have discovered that transparent graphene could solve this problem due to the unique band structure in the transmission spectrum of graphene that prevents the mentioned limitations. Theoretically, graphene allows the hot ballistic charge carriers produced by light  to transin vivo. in vivo. Moreover, these cellular-scale methods enable the recording of electrophysiology and calcium fluorescence in CA1 pyramidal neurons in hippocampus seizures  region . Recentlin vivo and achieved ultra-efficient tumor ablation after laser treatment. Similarly, in vitro. However, the rGO-PEG showed concentration-dependent cyto- and geno-toxicity. No toxic signal was found in the histological examination of GO-PEG during PTT by Liu operation. Another transition metal disulfide that is attracting more interest in the biomedical field is Tungsten disulfide because of its photothermal properties, high lubricity, and catalytic activity. Its high NIR absorption capacity has been applied to photothermal therapy of tumors .PTT has received widespread attention because it can thermally ablate cancer cells in a minimally invasive manner under an NIR laser. The broad optical absorption spectra are important in photothermal medical applications. Nanomaterials with strong absorption in the NIR regime can act as effective PTT absorbers that achieve therapeutic temperatures with less total light energy, reducing heat escaping from the target to healthy surrounding tissue and avoiding tissue damage. GO and rGO have been widely exploited as effective absorbers for NIR-based PTT in cancer therapy . Clinicaf tumors . The devPhotoacoustic and fluorescence imaging can also be combined with PTT for diagnosis. Photoacoustic imaging has few specific signals and cannot image deep tissues. Fluorescence imaging does not use ionizing radiation and has low tissue penetration. Thus, further research is needed to fully understand how to apply carbon nanomaterials better and fully in neurology, as their functions involve the interaction between their various properties. Therefore, improving the functionalization of nanomaterials, which can create better and less risky options for patients during clinical treatment of diseases, remains challenging.5.9 W m−2 K−1. −1 K−1.Graphene has high thermal conductivity (κ) and great thermal management potential, indicating its development in nanoscale engineering for heat transport and management. Researchers have suggested various effective approaches for modulating the thermal conductivity of graphene. Depositing nanoparticles on the surface of graphene can mediate its thermal management . Chemicain vivo  accumulation. Recently, As thermal stability improves, graphene use has risen in the fields of clinical biomedical application and tailored nanomedicine for neurologic diseases. For example, graphite lattices in the graphene family of nanomaterials fuse to form disparate forms of molecules, with a potential role in drug and gene delivery for treating neurological diseases. Using two complementary strategies for conferring static or spatial stability can improve the thermal stability of graphene and allow cells to occupy stable graphene sheets . In 2008in vivo . The comThese findings provided new ideas for combining PTT and graphene-based drug/gene delivery therapy and demonstrated a significant improvement over traditional surgical treatment method. Graphene-based materials showed high potential for the novel and efficient treatment of neurological disorders. However, the interaction between graphene and cells may interfere with the different cell viability reduction rates in thermal therapy . Future 6.The first aspect to consider when developing graphene-based biomedical applications is their biocompatibility to avoid any adverse effects on living tissues . GraphenGraphene biocompatibility and its effects on the performance of living cells have shown that graphene on top of matrix substrates does not impede the interaction between neurons and substrates, thus maintaining neuronal viability . Li et ain vivo studies have demonstrated that the immune system is highly sensitive to graphene and quickly responds by increasing anti-inflammatory cytokine synthesis (in vivo zebrafish model (in vivo settings. Fabricating graphene with poly(ε-caprolactone) caused an acceptable degree of immunological response in vivo  in in vivo mouse experiments did not accumulate in main organs with fast kidney clearance, probably due to their ultra-small size  and low (up to 70 kΩ−1) conductivity favored neuron spreading without clear alteration, indicating that the high electrical conductivity of graphene is not the crucial property and the efficient range of its electric conductivity for graphene-based neuronal interfaces is broader than expected  to ensure the delivery of sufficient dosage to kill cancer cells. Second, the delivery should specifically target cancer cells, avoiding harmful effects on normal tissues. For example, subarachnoid hemorrhage occurs in severe neurological diseases, and studies have demonstrated the feasibility of using functionalized GO (FGO) for effective drug delivery in such cases. The content of FGO nanotablets loaded with pirfenidone, which is used to treat subarachnoid hemorrhage, gradually increases with an increase in drug concentration , making 1-42 (Aβ1-42) is an important biomarker in AD and PD  in neuroscience in e repair , we founin vitro and in vivo studies suggest that current studies have several limitations. First, compared with the number of in vitro studies, in vivo studies exploring the basic properties of graphene, specifically its biocompatibility and toxicity are limited. Lack of consistency between in vitro and in vivo results may downgrade graphene into only a research tool. Regarding in vivo study models, nearly all animal models are limited to mice, and no other species have been considered in exploring graphene applications. Second, most studies suggest that nanomaterials induce a mild immune response. However, researchers are yet to identify the standard method of administration. Furthermore, whether nanomaterials act the same way when eliciting an immune response via different routes of administration in vivo remains unknown, although the toxicity and pharmacokinetics of nanoparticles are closely dependent on the administration route. Third, most studies, whether in vitro or in vivo, did not perform in-depth investigations on the underlying mechanism involved in the relationship between cell differentiation and graphene-based substrates, such as induced morphologic interplay and cellular modulation pathways. Without these fundamental definitions, determining the role of graphene in biomedical applications may be challenging.The observed discrepancies in in vivo because the results from in vitro studies cannot be directly applied to humans. Moreover, the graphene-based implant as an electrode or scaffold should also be further investigated to observe its long-term effect in vivo. More animal models should be considered to clarify the relationship between different species and graphene. Second, graphene can exhibit long-term and short-term toxic effects on the same cell and can potentially cause long-term damage to cellular structures. This review highlighted that graphene toxicity is highly dependent on excretion, functionalization, size, and structural dimensions. Therefore, comparing graphene toxicity between different experiments is difficult, given its diversity in shape, surface, size, and fabrication. Thus, the fabrication and terminology of graphene and the examination of toxicological methodologies must be standardized. This will better aid the understanding of the physicochemical properties and potential toxicity of graphene in vivo and in intro, allowing its practical application in humans. Third, future studies should incorporate graphene with various optical components to probe deeper brain tissues and understand how brain circuits process information because a graphene electrode with a two-photon microscope can record the whole cortical surface in neuroscience investigation. Moreover, electrical stimulation has been clinically applied in rehabilitation after nerve injury. Graphene-based conduits have shown great potential in nerve repair as scaffolds. Future studies should measure the potential of combining electrical stimulation and graphene-based conductive scaffolds in clinical nerve repair.The following are proposals for future experiments for improving graphene and its derivatives development: First, the main consideration of nanomaterials in biomedical application is their biocompatibility. Further studies must focus more on biocompatibility and toxicity This review sheds light on the safety and biological properties of graphene that must be considered before the utilization of graphene-based therapy for human benefit. This may pave the way for using graphene and its derivatives as powerful materials with versatile scientific and clinical applications.TY and YY wrote the first draft of the manuscript. L-YM and YL wrote sections of the manuscript. JB, F-YW, and LZ reviewed the literature. All authors contributed to manuscript revisions as well as read and approved the submitted version.This work was supported by the National Natural Science Foundations of China , the Innovation Team Project of Yanbian University (China), and the International Cooperation Project of Science and Technology Department of Jilin Province (20210402004GH).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.


Tunable and low-power microcavities are essential for large-scale photonic integrated circuits. Thermal tuning, a convenient and stable tuning method, has been widely adopted in optical neural networks and quantum information processing. Recently, graphene thermal tuning has been demonstrated to be a power-efficient technique, as it does not require thick spacers to prevent light absorption. In this paper, a silicon-based on-chip Fano resonator with graphene nanoheaters is proposed and fabricated. This novel Fano structure is achieved by introducing a scattering block, and it can be easily fabricated in large quantities. Experimental results demonstrate that the resonator has the characteristics of a high quality factor  and low state-switching power (∼1 mW). The temporal responses of the microcavity exhibit qualified modulation speed with 9.8 μs rise time and 16.6 μs fall time. The thermal imaging and Raman spectroscopy of graphene at different biases were also measured to intuitively show that the tuning is derived from the joule heating effect of graphene. This work provides an alternative for future large-scale tunable and low-power-consumption optical networks, and has potential applications in optical filters and switches. In the past decade, silicon photonic integrated circuits (PICs) have been regarded as one of the most promising platforms for realizing high-performance and multifunctional on-chip photonic devices. Microring resonators (MRRs), as one of the most fundamental components in silicon PICs, are widely used in the area of modulation ,2, filteThermo-optic tuning is an effective way to realize tunability owing to the large thermo-optic coefficient of silicon   material composed of a single layer of carbon atoms, has been extensively investigated due to its diverse and charming optoelectronic properties ,18,19,202/V·s ,22. In t2/V·s ,24, prov2/V·s . On the 2/V·s ,28,29,30To further improve the performance of this type of devices, in this paper, we present a thermally tunable resonator that combines graphene nanoheaters with high heating efficiency and Fano resonators with low switching-energy requirements. The Fano resonator is achieved via the incorporation of microring resonators (MRRs) with a scattering rectangle block that could be easily fabricated using deep ultraviolet (DUV) lithography. Experimental results demonstrate that the Fano resonator with a graphene nanoheater requires only ∼1 mW for “on/off” state switching, and has a narrow line width of ∼0.05 nm, outperforming previous on-chip thermally tunable silicon devices . The resFano resonance is a widely known phenomenon that occurs when a narrow discrete constructive or destructive state interferes with the continuum band of states . CompareTo achieve asymmetric Fano line shapes, as shown in R = 30 μm, To plot the theoretical transmission spectra, we set the parameters as follows: cies see .Sample fabrication. The Si photonic platform was prepared by the MPW foundry  with standard processes of DUV lithography and inductively coupled plasma etching, followed by the deposition of 2 μm thick silica as the upper-cladding layer. To avoid the crack of graphene caused by the height difference of the waveguides, we then used a CMP machine (LOGI TRIBO) to planarize the top surface of the silica and thin it down to about 180 nm. The thickness of the top silica layer was measured with the ellipsometer. To remove silica nanoparticles introduced by the CMP step, the sample was cleaned using ultrasonic cleaners for 15 min. Graphene and hBN flakes were mechanically exfoliated from highly oriented graphite and hBN crystals, respectively. The hBN and graphene were stacked with the van der Waals assembly technique [2:CHF3:Ar (10:20:10) SCCM environment for 2 min to expose the graphene edge.Metal electrodes were fabricated via electron-beam evaporation and the lift-off of 5 nm Cr/50 nm Au.echnique ,46  with a fiber polarization controller to maximize the input power. The output power of the tunable laser was generally fixed at 1 mW, and the coupling efficiency of the gratings was approximately 8 dB. For the measurement of static characteristics, the output fiber was connected to a high-sensitivity power meter (THORLABS PM100). A DC signal was applied to two probes with a sourcemeter (KEITHLEY 2636B). For thermo-optic temporal response measurement, the output fiber was first connected to a photodetector (THORLABS PDA50B2) and then a real-time digital oscilloscope (YOKOGAWA DL6154). The RF signal was generated by an arbitrary waveform generator. The signal was split in the oscilloscope to monitor the source  platform with an hBN–graphene heterostructure, as illustrated in h enough . Correspm is the resonant order, the resonant wavelengths redshifted. As plotted in To verify the device’s thermal tunability, a DC bias was applied to the graphene using a sourcemeter through the pads. Since the resistance of graphene is higher than that of other parts of the electric circuit, the joule heating effect was mainly concentrated on the graphene. With the increment in voltage, the heat generated by graphene diffused into the core of the waveguide through the top silica layer. Consequently, the effective refractive index , and the incident wavelength was fixed at 1548 nm , the graphene part could not be photographed more clearly. Although we compensated for the emissivity of different materials via temperature correction before capturing, for low-emissivity materials, software emissivity compensation alone is susceptible to significant errors due to variation in surface emissivity and errors in the control temperature measurement process. To overcome this problem, the average temperature of the dashed area was calibrated with the Raman spectroscopy of graphene (see To show the tuning derived from the joule heating effect of graphene, hene see . As show3 solution [There are two methods to further improve the performance of a Fano resonator. First, the optical losses of monolayer graphene can be electrically or chemically suppressed by improving the Fermi level of graphene to Pauli blocking regions . Chemicasolution  could besolution . This heIn conclusion, we proposed and demonstrated low-power-consumption thermally tunable on-chip Fano resonators with graphene nanoheaters. The Fano resonators comprised an MRR and an especially designed scattering block, and are compact and easy to prepare. The graphene was laid on top of the planarized microring to act as a heating electrode. The fabricated Fano resonator showed energy consumption characteristics of down to ∼1 mW, and a spectral resolution as narrow as ∼0.05 nm. The low power consumption was mainly due to two aspects: the designed asymmetric line shape greatly reduced the required energy of state switching, and using graphene as the nanoheaters reduces the thickness of spacers that are required in conventional metal electrodes. Our results provide a promising building block for massive on-chip integrated devices, and may have applications in optical filters and switches.


The Growing demands for humidity detection in commercial and industrial applications led to the rapid development of humidity sensors based on different techniques. Surface acoustic wave (SAW) technology is one of these methods that has been found to provide a powerful platform for humidity sensing owing to its intrinsic features, including small size, high sensitivity, and simple operational mechanism. Similar to other techniques, the principle of humidity sensing in SAW devices is also realized by an overlaid sensitive film, which serves as the core element whose interaction with water molecules is responsible for overall performance. Therefore, most researchers are focused on exploring different sensing materials to achieve optimum performance characteristics. This article reviews sensing materials used to develop SAW humidity sensors and their responses based on theoretical aspects and experimental outcomes. Herein the influence of overlaid sensing film on the performance parameters of the SAW device, such as quality factor, signal amplitude, insertion loss, etc., is also highlighted. Lastly, a recommendation to minimize the significant change in device characteristics is presented, which we believe will be a good step for the future development of SAW humidity sensors. Humidity is an important environmental variable that plays a decisive role in our daily lives. In addition to human comfort, its detection and control are necessary for various manufacturing and storage environments to achieve optimum quality in production ,2,3,4. FTo fulfill humidity detection demands, great efforts have been made to develop humidity sensors based on different operational mechanisms. According to the sensing techniques, these sensors are typically categorized as capacitive ,6, resisFor practical implementation, the humidity sensor must possess satisfactory traits, including high sensitivity, wide detection range, low hysteresis, good linearity, good repeatability, quick response, and short recovery time. Additionally, the factors such as compact size, low power consumption, low cost, and compatibility with fabrication processes pave the way to make the sensor design an optimal choice for practical applications. Acoustic sensors have already been found to possess these inherent characteristics.Among different types of acoustic wave devices, Surface acoustic wave (SAW) devices have captured wide attention owing to their simple detection mechanism, easy integration, high sensitivity, good stability, small size, low cost, high accuracy, planar structure, and capability to operate in wireless mode ,20,21. TThe overlaid sensing film is the main determining factor to attain maximum effectiveness of the SAW humidity sensor. Therefore the researchers are mainly concentrated on exploring different sensing materials to optimize the parameter of interest. This article reviews the SAW humidity sensors developed in nearly three decades. Firstly the basic mechanism is elaborated, followed by a detailed review of humidity-sensitive materials. Herein, data on device design, sensing materials, and performance characteristics of various existing SAW humidity sensors are summarized in tables. Moreover, the influence of overlaid sensing materials on the characteristics of SAW devices is addressed in this article. Lastly, a recommendation is presented for the future development of SAW humidity sensors.The operation of humidity detection is realized by a sensing film overlaid on the surface of the SAW device. Any perturbation on the surface due to the absorption/desorption of water molecules affects the intrinsic parameters  of the sensing film, which alters the wave characteristics. The variation in propagating acoustic wave velocity ∆vh is the sensing film thickness, Here, In Equation (1), the first term represents the variation in propagating wave velocity caused by the mass loading effect, i.e., mass density change due to the interaction of vapor molecules within the sensing film. The second term characterizes the alteration in wave velocity due to elastic loading, i.e., the modulus change. The last term illustrates the variation in wave velocity by the acoustoelectric effect, the change in electrical properties such as conductivity and permittivity. All these changes in velocity can be monitored in terms of frequency or phase shift. The algebraic signs in Equation (1) illustrate that the velocity shifts positively with elastic loading and negatively with mass and electric loading. The effect of elastic loading on the sensor response is mostly neglected for semiconducting metal oxides, ceramics, nanostructured and carbon-based materials, as the alteration in mechanical properties due to the vapor molecules absorption is negligible for these sensing materials. Therefore, the mass loading effect is mainly considered the dominant mechanism for SAW humidity sensors. However, in earlier studies, some researchers had observed a significant effect of elastic loading, particularly for viscoelastic polymer films ,29. FurtIn most of the polymer-based SAW humidity sensors, the elastic effect contributes in the same direction as the mass loading effect, i.e., the decrease in velocity (negative frequency shift), mainly due to the reduction in the modulus ,31,32, kThe sensing material coated over the surface of the SAW device is an integral part of humidity detection, which has the sensitivity to grab water molecules and give rise to sensor response based on operational mechanisms . For implementation, sensing material is required to meet a variety of specifications such as strong adhesion with the substrate, good ability to absorb water vapors, long-term repeatability, lengthy operational lifetime, repeatable, quick, and reversible interaction with the water molecules ,36. TherPolymers have become one of the most extensively used humidity-sensitive materials for over 30 years. They have gained particular attention as humidity sensing layers for SAW devices owing to their high response to water molecules, room temperature operation, low cost, and simple coating techniques. Up to present, polyimide (PI), poly (PVA), polyXIO, poly(N-vinylpyrrolidone)(PVNP), polyaniline (PANI), conjugated polymers, poly(p-diethynylbenzene) (PDEB), sodium polysulfonesulfonate (NaSPF), polyvinyl pyrrolidone (PVP) and sulfonated tetrafluorethylene copolymer(Nafion) are reported as humidity sensing membranes in SAW devices ,49,50,51Li et al.  investigIn addition to exploring polymers as humidity-sensitive materials, some researchers have presented the possibilities of improving the performance characteristics by altering the physical parameters of the sensing layer, such as thickness, densities, and mechanical adhesion ,54,55. IApart from physical parameters, the modification in the chemical properties of the sensing film can also aid in improving the sensing characteristics. In , the pol® film deposited with two different techniques, i.e., thermal evaporation and electrospraying. The film deposited by the vacuum evaporation method agglomerated into bubbles, while the electrospray-deposited film was uniform. Moreover, the electrospray Nafion® film showed lower sensitivity and detection limit but quick response time compared to thermal evaporated Nafion® film. Apart from deposition techniques, the conditions and parameters of the deposition methods also affect the humidity response of the sensor. Li et al. [Furthermore, selecting the proper coating technique is another essential factor for optimizing performance characteristics. JASEK et al.  charactei et al.  examinedi et al. . The PVPTo gain the maximum effectiveness of the humidity sensor, it is of utmost importance to carefully select various factors such as thickness, density, physical and chemical properties of sensing film, deposition technique, and their condition and parameters.3O4, CuO, TiO2, and SnO2 have been explored as the humidity sensing films for SAW devices. Among these, ZnO is versatile and one of the most extensively investigated metal oxides. The nanocrystalline ZnO [2), Al2O3, etc., are also used as humidity-sensing membranes due to their porous nature, which is advantageous to provide a large surface area for water molecules absorption. Tang et al. [3O4, CuO, TiO2) and SiO2 films coated on quartz SAW resonators. They obtained much higher responses with sol-gel SiO2 films and observed the increased response with the increase in SiO2 film thicknesses, as shown in 2 film, which facilitates the absorption of water molecules due to the large surface area. On the contrary, the metal oxide films were smooth, dense, and less porous, as shown in SEM and AFM images in 2O3) is another porous ceramic material utilized as the humidity-sensing membrane for SAW devices [Polymer sensing films show good sensing characteristics at room temperature, but their stability and repeatability are adversely affected in different environmental conditions, especially at higher temperatures. To overcome stability issues, metal oxides are utilized as an alternative due to their high thermal stability. Metal oxides such as ZnO, Coline ZnO ,38,60, Gline ZnO , and difline ZnO ,63 are e devices ,65.In recent years, the improved sensitivity based on large surface area escalated the development of nanostructured coatings as the humidity sensing material for SAW sensors. Till now, a variety of nanostructures has been synthesized, including nanofibers ,66,67, n2) and applied it in respiration monitoring. High sensitivity was obtained by the synergetic effect of large diffusion/viscoelastic/mass loading effects with the arrangement of 3DAG/PVA/SiO2 layered structure, respectively.Likewise, owing to the large surface-to-volume ratio and the presence of hydrophilic functional groups, graphene oxide (GO) has become fascinating material for developing humidity sensors. Graphene oxide is a carbon-based material with oxygen-containing, i.e., carboxyl groups, which are hydrophilic functional groups that provide the feasibility of water molecules absorption. Balashov et al.  comparedGraphene-based sensing materials provide good sensitivity, but surface contamination, long-term drift, poor reproducibility, environmental pollution, and explosion hazards are some of their big disadvantages. Each kind of sensing material has advantages and disadvantages. 3 SAW delay line. Similarly, Su et al. [2 for respiration monitoring, as shown in 2) based SAW humidity sensor was found to detect the different breath levels, i.e., normal, deep, fast, and rapid. In addition, the same humidity sensor was capable of detecting the noncontact motion of fingers due to the generation of the sharp gradient field of humidity around the fingertip. These outcomes suggest the applicability of SAW humidity sensors in different applications. Moreover, these works indicate that the SAW humidity sensors with high sensitivity, fast response-recovery time, good repeatability, and stability are appropriate for respiratory monitoring and human activity detection.The main traits of humidity sensors are high sensitivity, low hysteresis, fast response time, quick recovery time, stability, durability, linearity, and wide sensing range. However, the conditions for humidity detection depend on the specific application. Breath monitoring and skin humidity detection are among the main applications of humidity sensors for human healthcare detection. Some researchers have successfully implemented SAW humidity sensors for respiration monitoring and noncontact detection of finger motion ,69,73,78u et al.  develope11) of about 15.44 dB with the SiO2 film coated on the surface of the SAW resonator, as shown in 2 film coated on the entire SAW device, and the loss was further increased with the deposition of PVA and graphene/PVA on the delay path of the SAW device, as shown in The overlaid sensing film works as the core element whose existence predominantly characterizes the humidity sensing of the SAW device. The deposition of any kind of sensing membrane permanently changes the device parameters such as resonant frequency, quality factor, signal amplitude, etc. Yan et al.  observed2/GO-based humidity sensors, as shown in 2-based SAW humidity sensor in [The decrease in quality factor and loss in magnitude further increases with the absorption of water molecules due to the change in mass loading of sensing film. In , with thensor in . Buvailoensor in  comparedensor in ,61,68,69Moreover, the parameters such as thickness, density, viscosity, etc., of the sensing film also influence the characteristics of the SAW device. Mostly the thicker films are utilized to obtain high sensitivity, which increases the mass loading, affecting the device characteristics, i.e., reducing the amplitude of the resonant peak and broader bandwidth . It shouThe significant change in device characteristics is mostly observed for polymer films and thicker coatings. The moderate loss can be acceptable as it originates from the change in mass loading on the SAW device, but the significant loss limits the practical implementation of the sensor. Therefore it is crucial to consider both the sensing characteristics and the performance parameters of the SAW device. There exist few studies that have addressed this issue. In  small-si2, etc., causes a significant change in the SAW device characteristics. To the best of our knowledge, the existing humidity sensors are based on traditional SAW device structures. According to [2 films at different areas of the two port SAW resonator structure consisting of three IDTs as illustrated in As mentioned previously, the deposition of some sensing materials, i.e., polymers, SiOrding to , the deprding to  investigrding to  analyzedTaking these findings as a foundation, our recommendation for the future development of humidity sensors is to modify the conventional SAW device and deposit the sensing film on the optimal regions of the modified design. This can be carried out by changing the design parameters and configuration of the SAW device so that the wave energy concentrate at the required regions of the device. As discussed before, the reflector-coated SAW sensor provides better device characteristics but low sensitivity, as the wave energy is concentrated toward IDTs. Our idea is to confine a part of the wave at the reflectors by delaying the wave energy and this can be conducted with the variation in the design parameters of the SAW device. So, the deposition of sensing film only on the reflectors can result in improved sensitivity, reduce the mass loading, and also aid in minimizing the significant loss of device characteristics that originate from the large mass loading of sensing film on the entire surface of the SAW device.This article summarizes the research on SAW humidity sensors. SAW devices are effectively utilized for humidity detection due to their tremendous features. Current studies are more focused on exploring new sensing materials to get the optimal performance of humidity sensors. Polymers, metal oxides, ceramics, and nanostructured and carbon-based materials are most commonly used as humidity-sensing films for SAW devices. Each of these materials has its advantages and disadvantages. A huge number of polymer-based humidity sensors with good performance characteristics were presented. However, the stability and repeatability of these sensors are adversely affected at high temperatures, which is one of the most sounded shortcomings. Contrarily, metal oxides are found as a good alternative due to their stability in different environmental conditions. Furthermore, ceramics, nanostructures, and carbon-based materials have captured particular attention owing to their porous and large surface areas, which provide the facility of vapor molecules absorption within sensing film, resulting in enhanced sensing characteristics. The overlaid sensing layer is the core element of humidity sensors, as the response highly depends on its interaction with absorbed water molecules. Hence, most of the current studies focus on exploring and altering sensing materials to enhance sensing characteristics such as sensitivity, detection range, linearity, hysteresis, response, and recovery time. As highlighted in this review, the deposition of some sensing materials causes a significant deterioration in the performance parameter of the SAW device, i.e., signal amplitude, bandwidth, insertion loss, Q factor, etc. This loss in device characteristics becomes worst with the absorption of water molecules, especially at high humidity levels, due to large mass loading. Therefore, despite exhibiting good sensing characteristics, such sensors cannot be implemented, as a narrow bandwidth, high-quality factor, and low loss are preferred for practical applications. It is necessary to consider the significance of device characteristics while optimizing the sensing characteristics to make the sensor suitable for practical applications. Few studies addressed this issue and attempted to overcome it by small mass loading effect and deposition of sensing film over the specific regions of the SAW device. Taking these works as a foundation, our recommendation is to modify the traditional SAW device  and deposit the sensing film over optimum regions of the modified design instead of covering the whole area of the traditional device. This can be a good step in the future development of SAW-based humidity sensors.


Secondary electron emission (SEE) is a fundamental phenomenon of particle/surface interaction, and the multipactor effect induced by SEE can result in disastrous impacts on the performance of microwave devices. To suppress the SEE-induced multipactor, an Ni (111) surface covered with a monolayer of graphene was proposed and studied theoretically via the density functional theory (DFT) method. The calculation results indicated that redistribution of the electron density at the graphene/Ni (111) interface led to variations in the work function and the probability of SEE. To validate the theoretical results, experiments were performed to analyze secondary electron yield (SEY). The measurements showed a significant decrease in the SEY on an Ni (111) surface covered with a monolayer of graphene, accompanied by a decrease in the work function, which is consistent with the statistical evidence of a strong correlation between the work function and SEY of metals. A discussion was given on explaining the experimental phenomenon using theoretical calculation results, where the empty orbitals lead to an electron trapping effect, thereby reducing SEY. Secondary electron emission (SEE) under electron bombardment is a very important effect of electron solid interactions, and plays an important role in many fields of applied physics such as magnetron sputtering, plasma physics, spacecraft potential, gas discharge, scanning electron microscope, etc. ,3,4,5,6.To date, many investigations have been conducted to reduce the SEY to suppress multipactor effects. Mature techniques for low SEY mainly include surface roughening ,13,14,15In addition, as early as 1950, Baroody  pointed Therefore, the aim of this work was to investigate the characters of the graphene/Ni (111) interface through theoretical calculations, and to design a feasible solution of low SEY based on this which could withstand the experimental verification. The greater expectation was to further obtain the underlying mechanisms and a practical law for seeking low SEY. Specifically, we were interested in how the calculated electronic properties affect the work function value and how this effect reflected on the SEY. All DFT calculations in this work were performed using Vienna Ab-initio Simulation Package (VASP) within the generalized gradient approximation (GGA) ,39 for tk-point mesh of 15 × 15 × 1. The cut-off energy for the plane wave basis was 1.3 times the maximum energy value based on experiential rules and so it was set to 520 eV, and the energy convergence criterion was set to 10−10 Hartree. Ground state calculations and optimization of the studied systems were performed using the pseudopotentials of the Perdew–Burke–Ernzerhof functional with the projector augmented wave (PAW-PBE). In the structural relaxation, one layer of atoms at the bottom of the substrate metal was fixed to simulate the bulk material, whereas the three layers on the surface were released. Relaxation ended when the maximum value of the interatomic force was less than 0.02 eV/Å. Furthermore, the work function φ calculated in this study was obtained by self-consistent calculations, as given by:z-axis averaging the electrostatic potential output LOCPOT, and The length of the vacuum gap was set to 16.57 Å, and the initial distance between surface nickel atoms and carbon atoms was 3 Å. With the convergence test, the first Brillouin zone was sampled using a Experiments were designed to verify the theoretical calculations. In the experimental preparation, single-crystal Ni (111) (cubic phase) samples were machined into dimensions of 10 mm × 10 mm × 1 mm in a class 1000 clean room . The nominal uncertainty of these samples was ±3 Å in the crystal direction, and the surface roughness was less than 100 Å. Then, graphene was grown on copper foils  via low-pressure chemical vapor deposition and later transferred to the surface of the nickel samples. The specific steps of this process are shown in The Ni (111) and graphene/Ni (111) surfaces were characterized by X-ray diffraction, a field emission scanning electron microscope (FE-SEM) , and Raman spectrometry (HR800). The X-ray diffraction pattern was used to determine the crystalline phase of the nickel surface, and the SEM images were used to show the morphology of graphene on the Ni (111) surface. The Raman spectra of the graphene-covered samples were obtained using an excitation laser at 532 nm to investigate the monolayer graphene.−1 and the G’ peak at 2690 cm−1, which can be seen in the Figure, indicating the presence of graphene. The G peak can be slightly different for graphene on different substrates such as Si, glass, and NiFe [The characterization results confirmed the applicability of the experimental samples. The crystal plane of the Ni (111) surface was confirmed by the characteristic angle of 44.7° in the X-ray diffraction pattern . Figure and NiFe ,42,43, cand NiFe .p-PDOS, the density peaks of the carbon atom in the composite were lower in the energy range of −15–10 eV, while the density peaks of the red nickel atom in the composite were higher in the energy range of 0–17 eV. For the d-PDOS from s- and p-electrons are the main contributors to the charge transfer. To show more detail, s and p orbitals of Ni, as well as the p orbitals of carbon. This implies the hybridization between the nickel atom and the carbon atom, which contributes to the transfer of electrons.More results of DFT calculations will support this deduction as presented in z-axis direction of the graphene/Ni (111) interface can be further used in a future correction of SEY Monte Carlo simulation. Considering the variation of fermi energy level after the composite, the work function φ can be calculated for this composite structure, as shown in the second column of In addition, the redistribution of the electron density at the graphene/Ni (111) interface leads to a variation in the electrostatic potential, thus affecting the probability of electrons emitting and exiting the interface as well as the work function as Equation (1). Work function and SEY were measured before and after the coverage. The SEY measurement was carried out using a home-made SEY system as outlined in sulators .(2)δ=Is−10 mbar and the irradiation of 21.22 eV photons (He I line).The ultraviolet photoelectron spectra of the Ni (111) surface and the graphene covered ones were obtained using an ultraviolet photoelectron spectrometer (UPS)   composite interface to suppress SEY, which were validated by the results from an experimental study of surface modification with graphene on an Ni (111) surface. Moreover, the results of theoretical calculations provided a way to reveal the mechanism of SEE suppression and work function decrease on graphene/Ni (111) surfaces. A general strategy for achieving low SEY surface modification was summarized, which manifested that the work function fication ,51,52. T


Ventilator-associated pneumonia (VAP) is commonly overdiagnosed & a primary driver of antibiotic overuse within intensive care units (ICUs). Antimicrobial stewardship programs have successfully leveraged diagnostic stewardship interventions (DSIs) to prevent overdiagnosis/overtreatment of diverse clinical syndromes, yet this approach has not been extended to VAP. In this trial, we aimed to evaluate the safety, feasibility & efficacy of a novel DSI care bundle (DSI-CB) targeting VAP.The DIVA trial (NCT05176353) was a pilot/feasibility trial conducted in 2 ICUs at Michigan Medicine from February 2022-February 2023. A DSI-CB targeting the respiratory culture testing pathway was implemented sequentially in study ICUs, using an interruptive electronic health record clinical decision support tool & modifications to microbiology laboratory workflows (Table 1). Providers were counseled on DSI-CB use during bimonthly educational sessions during trial rollout & via monthly email reminders thereafter. Rates of prespecified co-primary safety and secondary efficacy outcomes were compared between the postintervention study cohort & 5-year preintervention historical controls using negative binomial regression. Interrupted time series analysis was used to evaluate ICU antibiotic utilization rates (ICU-AURs) to account for temporal trends.1810 patients were admitted to study ICUs following DSI-CB implementation, 29% of whom were eligible for DSI-CB use. DSI-CB was utilized in 77% of eligible patients. Patient demographics, comorbidities & measures of acute severity of illness were similar pre- & post-intervention. DSI-CB implementation was not associated with increases in primary adverse safety outcomes (Table 2). DSI-CB implementation was associated with significant reductions in rates of total respiratory cultures ordered, rates of positive respiratory cultures & reductions in both total & broad-spectrum ICU-AURs .Implementation of a novel VAP DSI-CB was safe, feasible & associated with significant reductions in rates of respiratory culture positivity and ICU-AURs. This represents the first trial of a DSI targeting VAP & a novel avenue for ICU antimicrobial stewardship. Large-scale trials are warranted.Owen Albin, MD, Biomeriux: Grant/Research Support|Charles River Laboratories: Advisor/Consultant|Shionogi: Advisor/Consultant Weirauch J. Andrew, RRT, Drager Medical: Equipment loaned for research purposes, but no monetary funds were provided.|Jones and Bartlett Learning: Honoraria Krishna Rao, MD, MS, Merck & Co.: Grant/Research Support|Rebiotix: Advisor/Consultant|Seres Therapeutics: Advisor/Consultant|Summit Therapeutics: Advisor/Consultant Keith S. Kaye, MD, MPH, Entasis: Advisor/Consultant|Entasis: Honoraria|GSK: Advisor/Consultant|GSK: Honoraria|Merck: Advisor/Consultant|Merck: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|VenatoRx: Advisor/Consultant|VenatoRx: Honoraria


Since its initial involvement in numerous neurodegenerative pathologies in 2006, either as a principal actor or as a cofactor, new pathologies implicating transactive response (TAR) DNA-binding protein 43 (TDP-43) are regularly emerging also beyond the neuronal system. This reflects the fact that TDP-43 functions are particularly complex and broad in a great variety of human cells. In neurodegenerative diseases, this protein is often pathologically delocalized to the cytoplasm, where it irreversibly aggregates and is subjected to various post-translational modifications such as phosphorylation, polyubiquitination, and cleavage. Until a few years ago, the research emphasis has been focused particularly on the impacts of this aggregation and/or on its widely described role in complex RNA splicing, whether related to loss- or gain-of-function mechanisms. Interestingly, recent studies have strengthened the knowledge of TDP-43 activity at the chromatin level and its implication in the regulation of DNA transcription and stability. These discoveries have highlighted new features regarding its own transcriptional regulation and suggested additional mechanistic and disease models for the effects of TPD-43. In this review, we aim to give a comprehensive view of the potential epigenetic (de)regulations driven by (and driving) this multitask DNA/RNA-binding protein. Epigenetic mechanisms in both general and specific neurodegenerative diseases are gaining momentum ,3,4,5,6.TDP-43 gained momentum in the neurodegeneration field when it was first discovered that almost all amyotrophic lateral sclerosis (ALS) cases and as many as half of frontotemporal dementia (FTD) cases present pathological ubiquitinated inclusions of TDP-43 ,8. SinceAt the functional level, TDP-43 is a highly conserved protein involved in the regulation of RNA processing. Mechanistically, TDP-43 is able to bind with different affinity both single-stranded (ss)RNA and ssDNA but also double-stranded DNA (dsDNA). From a structural point of view, the binding of TDP-43 to nucleic acids is mediated by two RNA recognition motif (RRM) domains in its N-terminal region ,21,22,23In agreement with its strong affinity for nucleic acids, TDP-43 localization is mainly nuclear, and cytoplasmic aggregation is attributed to pathological processes. However, it is now well recognized that TDP-43 is capable of shuttling back and forth from the nucleus to the cytoplasm, even under normal physiological conditions . On the Being a DNA/RNA-binding protein, TDP-43 is highly involved in many aspects of RNA metabolism, such as the control of alternative splicing (AS), microRNA (miRNA) processing, and messenger RNA (mRNA) stability and transport ,34,35,36UG-repeated sequences within RNA [During the last decade, TDP-43 has been mostly studied for the functions linked to its RNA-binding properties. Notwithstanding this focus, initial studies established the capacity of TDP-43 to bind to ssDNA TG repeats with at least the same efficiency as it does to thin RNA ,16,19,22thin RNA . Insteadthin RNA ,20,21 anthin RNA .More recently, additional studies have found TDP-43 to be able to specifically bind DNA sequences in promoter regions and affect the expression of several genes ,47,48,49As already mentioned, the function of TDP-43 as a more general transcriptional activator/repressor has been known for about a decade . Its invDrosophila leg, Sreedharan et al. identified three factors, namely, sgg/GSK3, hat-trick, and xmas-2, needed to mediate TDP-43Q331K toxicity [xmas-2 or hat-trick, implicated in chromatin remodeling and RNA export, affected TDP-43 post-transcriptionally, resulting in a reduction in TDP-43 protein level [For example, using a mosaic genetic screen to study motor neuron degeneration in the toxicity . Interestoxicity . Among ttoxicity . In paratoxicity ,55. Finain level .Drosophila photoreceptor neurons [In addition to this evidence, two recent studies using the suppressor screen techniques have led to the identifications of other epigenetic modifiers able to contrast TDP-43 neurotoxicity. In these two studies, human TDP-43 was over-expressed in a subset of  neurons , motor n neurons . Then, u neurons , while B neurons .e(y)3/PHF10; polybromo/BAF180; ash1/ASH1L; enok/KAT6A; br/-; Br140/BRPF1; and mor/BAF170S/MARCC2. The remaining, the Chromodomain-helicase-DNA binding protein 1 (Chd1) with two human homologues, CHD1/CHD2, is an ATPase involved in the remodeling and assembly of chromatin [Numerous genes implicated in nucleocytoplasmic transport or in pathways that are deregulated in TDP-43-related neurodegeneration were identified among the glial and motoneuronal TDP-43 suppressors of toxicity. However TDP-43-phenotype suppressors were principally composed of chromatin remodeling and basal transcription machinery factors. In particular, 25% of them were chromatin remodelers. Seven out of eight of these factors promote open chromatin as part of the Trithorax and SWI/SNF (Brahma) complexes, most of them with human known homologues: hromatin . Furtherhromatin . By hijahromatin . The ChdChd1 KD could cause an opposite effect on TDP-43 overexpression-mediated toxicity; in particular, instead of counteracting the effects of TDP-43 overexpression upon motor neurons KD, an exacerbation of toxicity was observed upon glial and photoreceptor neurons KD [Importantly, according to the different brain cells investigated, it was also observed that urons KD ,52. Thesurons KD .C. elegans, it was found that the TDP-43 homolog, TDP-1, could regulate the chromatin localization of another chromatin remodeler, HPL-2, the heterochromatin protein 1 homolog [tdp-1 mutant worm [Changing the model organism to  homolog . Direct ant worm . As a siant worm ,35. At tC9orf72 GC expansion (C9ALS) or sALS without mutations in common ALS-linked genes [Additional evidence of TDP-43 function in chromatin remodeling and its relevance to neurodegenerative diseases comes from the study of nBAFs proteins in cultured mouse motor neurons expressing ALS-linked mutant (G418C and A315T) human TDP-43 . The Braed genes .M337V, whereas TDP-43WT overexpression led to a significant increase in H3K9me3. On the contrary, no relevant global losses or gains of these epigenetic marks were observed for the TDP-43A382T mutant [The contribution of TDP-43, and especially of its ALS-related mutants to more global epigenome alteration, was also recently tested in the human neuroblastoma SH-SY5Y cell line, together with other ALS-causative proteins, SOD1 and FUS . In thisT mutant .WT expression [In line with these findings, the fly Chd1-TDP-43 interaction study previously mentioned was part of a broad in vivo RNAi screen to search for TDP-43 toxicity modifiers . This scpression . Note thpression .HDAC6 mRNA, regulating both its mRNA and protein expression in neuronal and non-neuronal cell lines [Drosophila model of TDP-43 proteinopathy reduced the amount of insoluble poly-ubiquitinated proteins and ameliorated the lifespan and climbing defects associated with the overexpression of both TDP-43 and Ataxin-2 (ATXN2). These results indicated that HDAC6 could modulate, albeit in a non-enzymatic manner, the TDP-43 activity via the autophagy–lysosome pathway (ALP) [Finally, two HDACs, HDAC1 and HDAC6, have been shown to influence and to be influenced by TDP-43, respectively. Thus, it has been shown that the silencing of both HDAC1 in SH-SY5Y and its fly ortholog Rpd3 in Drosophila is able to mitigate the toxic effect induced by TDP-43 expression . Notablyll lines ,60. In oll lines . On the ll lines . In 2020ll lines . They foay (ALP) . NAP1L1 genes, on the contrary, were all downregulated [Hist1h3 and Hist1h4 mRNAs were aberrantly polyadenylated, while at least 10 out of 15 variant histones were slightly but significantly downregulated in the TDPΔNLS bigenic mice [At the level of gene expression, substantial alterations were observed in the cortices of transgenic mice expressing inducible WT or mutant hTDP-43 lacking the nuclear localization signal (tTA/TDPΔNLS). These alterations appeared even before the onset of significant gliosis and neuronal cell loss . Despiteegulated . Althougegulated . In partnic mice . In partnic mice , thus fuTo relate these findings to the human pathological condition, it is now known that not all cells in the brain of a patient present a reduced load of nuclear TDP-43, and the transcriptome of these cellular populations was recently investigated . To achiDNA methylation is another major epigenetic modification, acting on DNA itself, rather than on the chromatin or nucleosomal proteins wrapped around it. At the biological level, DNA methylation is established via DNA methyltransferases (DNMTs) and is passively erased during DNA replication or, as can be more relevant for neuronal cells, by active replication-independent mechanisms involving oxidations steps mediated by the ten-eleven translocation (TET) enzymes and base excision repair ,67,68. DC9orf72, TARDBP, SOD1, or FUS, as well as datasets from patients’ biopsies [No relevant changes in global DNA methylation were observed by Masala et al. in the human neuroblastoma SH-SY5Y cell line overexpressing WT or mutant ALS-linked proteins, including TDP-43, as cited above ; howeverbiopsies . Analysibiopsies . These rbiopsies . In addibiopsies . MeCP2 ibiopsies .Cell cycle alterations have also been reported following TDP-43 suppression. In two recent publications, TDP-43 activity was linked to sister chromatid cohesion through the splicing regulation of a cohesin complex subunit, namely, Stromal Antigen 2 (STAG2). In particular, depletion of TDP-43 in HeLa and neuroblastoma cell lines upregulated STAG2 exon 30b inclusion ,78. AccoTAF1, and e(y)1 orthologs of the mammalian TAF1 and TAF9 transcription factors, members of the TFIID initiation complex, and also Tombola involved in the transcriptional activation of the male germline during meiosis [Finally, genes related to transcriptional machinery constitute another broad category of TDP-43-phenotype suppressors that have been identified thanks to several screening techniques. These genes include the transcription elongation factor, Su(Tpl) ,79, whic meiosis . The alt meiosis , thus reTaken together, these studies on chromatin factors interacting with, modified by, or phenotypically rescuing TDP-43, indicate a potentially important role of TDP-43 as an epigenetic regulator with a high capacity for modulating chromatin, transcriptional processes, and DNA damage/repair pathways. A synthesis of the identified factors can be found in Since 1995, when TARDBP was first identified as being able to bind TAR motif within HIV proviral DNA , a dozenAcrv1 gene coding for the sperm acrosomal protein SP-10 led to the discovery that TDP-43 can bind and repress this gene [Acrv1 was found to occur in vitro via two GTGTGT motifs located within the Acrv1 promoter and the N-terminal RRM1 domain of TDP-43. TDP-43 was able to tether Acrv1 at the nuclear matrix, impeding promoter–enhancer interaction, thus acting as an insulator [Acrv1 gene promoter in several non-neuronal tissues and cell lines, with different intensities, but it was not always able to maintain transcriptional silencing. However, TDP-43 presence in spermatocytes was necessary in order to Acrv1 silencing at this stage. As the authors mentioned, this suggests that biological conditions exist under which TDP-43 does not act as a transcriptional repressor [Acrv1 promoter TDP-43-mediated repression was specifically associated with histone H3 dimethylated K9 (H3K9me2) [For example, studies on the testis-specific mouse his gene ,39,40. Ac-fos core promoter by using a fusion construct between the DNA-binding domain (DBD) of Gal4 protein and TDP-43, and by coding Gal4-binding sequences upstream of the c-fos promoter. In HeLa cells, the use of this system led to the repression of the downstream luciferase reporter gene, respective to the use of Gal4 DBD protein alone. Similar constructs with Gal4 DBD fused to p53 protein, on the contrary, enhanced luciferase expression [This study also illustrated a potential generic repressor function of TDP-43. This property was demonstrated by artificially bringing TDP-43 in proximity of the pression , therefoParticularly relevant for ALS is the work of Schwenk et al., that revealed a mechanistic link between nuclear loss of TDP-43, TDP-43 gene expression regulatory functions and trophic signaling alteration in neurons . The autneuroLNC and found it to strictly localize in the cell nucleus and to be implicated in synaptic vesicle (SV) release. neuroLNC lncRNA is conserved from rodents to humans, and its expression appears highly restricted to the brain, and more specifically to neuronal cells. Interestingly, mass spectrometry (MS) analysis for protein interactors highlighted TDP-43 as the highest and only highly significant enriched protein interacting with neuroLNC. Further IP assays against TDP-43 confirmed their interaction and featured the importance of the neuroLNC RNA UG-repeats in the interaction, since a neuroLNC with mutated UG-repeats loses its ability to bind to TDP-43. At the functional level, downregulation of TDP-43 abolished the effects of neuroLNC overexpression on synaptic vesicles, and the UG-repeats-mutated neuroLNC was unable to potentiate SV release. Like TDP-43, neuroLNC is chromatin-associated, as shown by DNA ChIRP-seq analysis, and localized chiefly at intronic regions (82%) and at the upstream regulatory regions (13%) of genes. The ChiRP also revealed the binding of neuroLNC to several classes of RNA. Gene ontology (GO) analysis of the DNA- and RNA-bound elements highlighted several neuronal genes implicated in neurotransmitter release, synapse organization, glutamatergic signaling, and regulation of neuritogenesis [neuroLNC in the nucleoplasm or on chromatin has not been clearly established, and whether neuroLNC promotes the transcription of these genes and/or the stabilization of the mRNAs that are bound will deserve future studies [neuroLNC in ChIRP experiments are only partially overlapping [neuroLNC that may not all be related to TDP-43. Another additional mechanism potentially linking TDP-43 nuclear functions to neuronal signaling was recently identified [neuroLnC is the best-characterized example of a neuron-specific lncRNA- TDP-43 interaction with implications on the regulation of gene/chromatin. However, there are additional examples already documented in other tissues that suggest a wider role for TDP-43–lncRNA interaction. For example, a previous study showed that TDP-43 is part of a proteins–lncRNA Xist condensate, and is required for anchoring Xist to the inactive X (Xi) and for the silencing of the Xi-territory in ESCs [Cyp8b1 transcription [lncLSTR, a liver-enriched nuclear lncRNA with lipid-lowering effects. Direct interaction of lncLSTR with TDP-43 was demonstrated via reciprocal pulldown experiments in liver tissue [At present,  in ESCs  . In this way, TDP-43 was found to act as a mediator of LPS promotion of the pro-inflammatory factor TNF-alpha, a result confirmed by both siRNA knockdown and the overexpression of TDP-43 [TNF-alpha mRNA upregulation [TNF-alpha promoter, and suggested that TDP-43 could be the factor by which NF-kB reaches the TNF-alpha promoter [Surprisingly, other examples of recent evidence indicate a role for TDP-43 in the positive regulation of the transcription of other genes. One example is represented by TNF-alpha activation in human monocytic cells THP-1, differentiated into macrophages by PMA and stimulated by LPS . Analysif TDP-43  , not acetylation-null (KK-AA) in the RRM1–RRM2 region of TDP-43, were found to abolish CHOP transcriptional activation. On the contrary, CHOP promoter activity was enhanced by HDAC1, which deacetylated WT TDP-43 [TNF-alpha and CHOP promoters are still unknown.Another recent study reported a case of TDP-43 behaving as a transcriptional activator using both ChIP and a luciferase reporter assay in SH-SY5Y, this time activating the C/EBP-homologous protein (CHOP) promoter, also known as DNA-damage-inducible transcript 3 (GADD153) . Indeed,radation . Recent promoter   [Myolinc and TDP-43 are critical to activating myogenic regulatory networks for the differentiation of myoblasts into myocytes and for the subsequent formation of multinucleated myotubes. Lack of Myolinc relocalized TDP-43 to other regions and abrogated activation of the myogenic regulatory network [Myolinc has been observed in other tissues, including in the brain, albeit at lower levels. In addition, an siRNA against TDP-43 not only significantly reduced the gene expression levels of these muscle genes but also that of Myolinc, suggesting that the Myolinc gene itself is also under the control of the TDP-43 protein [MyoD1 in Porcine muscle satellite progenitor cells, thus representing another lncRNA involved in TDP-43-mediated muscle differentiation. Although the precise underlying mechanisms at play are yet to be elucidated, H19 has already been reported to directly interact with TDP-43 [As shown for TDP-43-mediated gene repression, gene activation can also be mediated by lncRNA-TDP-43 interaction. Thus, in mouse skeletal muscle, the interaction of TDP-43 with a muscle-enriched lncRNA called  Filip1)   repeat expansions, and the PCR2 HMT subunit EZH2 was found largely insoluble [About 7 years later, a higher resolution of the genome localization of TDP-43 was first given on its Drosophila homolog, TBPH, by a plethora of experiments based on ChIP-seq, RNAi depletion, transcription blockade, affinity chromatography, and immunoprecipitation conducted in Drosophila . This stnsoluble . Interesnsoluble . TDP-43 nsoluble . siRNA-insoluble . Still, nsoluble . As TDP-C9orf72 poly(PR) ((PR)50) mutant and the interesting finding that (PR)50-induced neuronal death can be dampened via p53 inhibition, the authors nonetheless obtained very interesting findings regarding TDP-43 neuronal overexpression. Despite the neurodegeneration looking “grossly similar”, the modifications of the underlying chromatin and gene expression programs were different. TDP-43 and C9orf72 (PR)50 conveyed unique chromatin and transcriptional footprints. Loss of chromatin accessibility was observed for all lentiviral-treated cultures, even the GFP control; however, a gain in chromatin accessibility was observed for TDP-43 after 60 h and associated with a chromatin more accessible for a variety of TFs, as evidenced via ChromVar, and several gene co-expression networks were deregulated [At the beginning of 2021, Maor-norf and colleagues, working on mouse cortical culture and combining ATAC-seq and RNA-seq, investigated the consequences on the chromatin accessibility of ALS-related protein overexpression . Though egulated , findingAs a result of these investigations, it appears that TDP-43 has a broad ability to affect the transcription of all categories of genes, from coding to non-coding classes, to a degree that is greater than had been previously appreciated. This can be achieved indirectly through the modulation of genes involved in chromatin remodeling and transcription, or directly via association with genes promoters. While direct, multimodal regulation, either repressive or activating, has, as discussed above, been reported for several genes, understanding of the general function of TDP-43 at the TSS of active genes genome-wide still requires further investigation. It was proposed that the transcription-independent binding of TBPH, and hence possibly of TDP-43, could serve to reduce the fluctuations in the levels of transcription over time, with the intriguing possibility that the aggregate-prone low-complexity C terminal domains in TBPH might also facilitate enhancer–promoter looping or loops stabilization .Acrv1 gene promoter activity during mouse spermatogenesis [Remarkably, Nie and colleagues reported very recently on the requirement of the maternal (oocyte) TDP-43 protein to activate the zygotic genome during embryogenesis by promoting RNA Pol II transition from a paused to an elongating state . Experimogenesis , the herogenesis . Overallogenesis , myogeneogenesis , and embogenesis ).Alongside the TDP-43 function in gene transcriptional regulation, several recent studies have strengthened the potential role of TDP-43 in genome stability and DNA repair ,94,95,96Upon DNA damage induced in pluripotent stem cell (iPSCs)-derived motor neurons from a healthy subject, or in differentiated neuronal line SH-SY5Y, normal TDP-43 is rapidly recruited at double-stranded breaks (DSB) sites. TDP-43 was shown to stably interact with DNA damage response (DDR) and neighbor homologous end-joining (NHEJ) repair factors. Specifically, it acted as a scaffold protein for the DDR complex  and the break-sealing XRCC4-DNA ligase 4 complex , mediating its recruitment at induced DSB sites ,93. In vitro experiments further showed that TDP-43 can directly bind dsDNA oligonucleotides with free blunted ends, but not if ends are biotin-blocked or in case of a ssDNA break , thus suAs expected from these findings, deprivation of TDP-43 led to an accumulation of DNA damage. As such, TDP-43 deprivation in cycling iPSCs-derived NPCs and SH-SY5Y conveyed an accumulation of endogenous DSBs, despite DDR activation, with an increase in γH2AX, p53BP1, and pATM at 96 h after TDP-43 KD . SubsequListeria monocytogenes [Listeria monocytogenes causes SIRT2 accumulation in the nuclear and chromatin spaces. SIRT2 is a deacetylase and its translocation to the chromatin provoked a global loss of H3 Lysine 18 acetylation (H3K18ac), a mark enriched at the TSS of transcriptionally active and poised genes. On a local scale, both SIRT2 and H3K18ac were redistributed. SIRT2 enriched at the TSS of a large subgroup of genes that lost H3K18ac and became repressed, and get depleted at other genes that gained increased H3K18ac and became activated [Additional insights into the protective role of TDP-43 against DNA damage and the mechanism behind it come from a recent work on the bacterial pathogen ytogenes . Upon inctivated . Eldridgctivated . Mechanictivated . As obsectivated . In the ctivated . In the ctivated , but itsPOLDIP3 exon 3 was significantly altered in different cell lines depleted for TDP-43 and other hnRNPs linked to TDP-43 functions [In addition to a direct intervention of TDP-43 at DSB site, TDP-43 was shown to be important for the production of two proteins involved in DNA repair, SIRT1 and POLDIP3 . SIRT1 is a Sirtuin implicated in dsDBR and is required for cell survival. RNA-IP and RNA pull-down assays in human neuroblastoma SH-SY5Y and embryonic kidney HEK293T cells demonstrated that TDP-43, in complex with FMRP  and STAU1 (Staufen) proteins, specifically binds to the 3′-UTR of SIRT1 mRNA and positively regulates its stability and hence its protein production  Figure D. In a cunctions ,77,78, aunctions . Althougunctions ,106. HowInterestingly, a role in the prevention and/or repair of DNA damage has also been proposed for FUS, another well-characterized fALS-linked protein, both in the motor neuron-differentiated neuronal cell line and in non-neuronal dividing cells ,107,108.Apart from their gene regulatory function, R-loops can also function to promote DNA repair, particularly in the context of transcriptionally coupled repair ,110. IntLnc530, localizes to R-loops, controls their levels, and preserves genomic stability. To understand how Lnc530 regulates R-loops, they performed in vivo RNA pull-down with MS analysis and found two strong candidates, DEAD-box RNA helicase 5 (DDX5) and TDP-43, with whom the Lnc530 forms a DDX5- Lnc530-TDP-43 complex that prevents unwanted R-loop formation and elevates the concentration of DDX5 and TDP-43. [Lnc530-TDP-43 complex, probably elevating the local concentrations of DDX5 and TDP-43 to regulate the resolving of R-loops [Lnc530 expression is much less abundant in differentiated cells, its ectopic expression in such cells effectively increased the recruitment of DDX5-TDP-43 at R-loops and reduced their aberrant formation [Lnc530 expression in different brain regions of mice at even higher levels than that in mESCs. If Lnc530 participate in TDP-43, R-loop regulation in mice brain is should be further examined. Similarly, the functionality of the human Lnc530, reported to show only partial conservation with mice Lnc530 [The key role of TDP-43 in preventing R-loop accumulation has been further highlighted in the recent work of Gong et al. . Studyin TDP-43. . RNA-pul R-loops . While Lormation . Interese Lnc530 , and it Q331K had a reduced interaction with XRCC4 and Ligase 4, both in unstressed and irradiated cells, and prevented XRCC4-Lig4 nuclear translocation. The authors showed that in addition to defective DNA repair, Q331K expression induced ROS stress, at least in cycling cells, thus fueling the vicious cycle [The link between TDP-43 function in DNA stability and ALS features was also supported by the fact that the spinal cord DNA of a ALS patient presenting the TDP-43 Q331K mutation showed a higher level of γH2AX, a DNA single- and double-stranded break marker, compared to age-matched controls . In the us cycle . Loss ofus cycle . This waus cycle . Finallyus cycle  . In parallel, their subsequent within-germline propagations by means of retrotranspositions or reinfections (copy–paste-like mechanisms) over millions of years led to the formation of several multicopy families that group under the long terminal repeat (LTR) class of TEs. Retroviral ORFs , pro/int/pol , env (envelope glycoprotein), and accessory proteins) accumulated disruptive nonsense mutations and proviruses often recombined leading to solo-LTRs. In the human, HERV-derived copies and fragments represent about 8% of our genomic DNA ,115,116.The long interspersed elements (LINEs) constitute another important class of retrotransposons; they are able to conduct autonomous self-propagation via another copy–paste mechanism thanks to their ORFs encoding ribonucleoproteins, endonuclease, and reverse transcriptase. They account for 17% of the human genome, and several of them, albeit representing a small fraction, are polymorphic within the population . They diOverall, TE subfamilies are species specific, but they rely on the same molecular mechanisms for their control and propagation , notablyBeing highly repetitive by nature, TEs are routinely dismissed from deep-sequencing analyses if not under specific focus, although new sequencing modes have greatly improved their mappability. However, by reanalyzing a series of deep sequencing datasets from RIP-seq and iCLIP-seq from normal brains of rat, mouse, and human, the group of Dubnau uncovered an extensive binding of TDP-43 to TE transcripts . In thisSOD1 mRNA (61%), or a strong bias for inflammation and pan-glial cells activation (19%).Importantly, this physiological binding of TDP-43 to TEs was observed to be altered in at least two of the major TDP-43 proteinopathies: FTLD and in a specific subtype of ALS ,138. In These conclusions were broadly supported by analyses performed in human SH-SY5Y neuroblastoma cells, where the use of CLAM, a tool designed to handle repetitive reads on sequencing data of TDP-43-bound RNA obtained by using enhanced cross-linking and immunoprecipitation (eCLIP-seq), unmasked 439 TE-derived RNA bound to TDP-43, corresponding to 31% of all mapping reads . SpecifiAll these data support a specific functional and conserved role for TDP-43 in the repression/regulation of TE elements. Importantly, misregulated TE expression can have a number of detrimental impacts on chromatin, such as those observed in ALS and other neurodegenerative diseases. They may include genome instability via the spurious integrations of new repeats, activation of the DNA-damage stress response, or deregulation of the neighboring genes A.pol gene containing mRNA, identified several actively transcribed loci in the HERV-K HML-2 and 3 subfamilies, including specific copies with protein coding potential lying within a candidate interval for MND, in which the susceptibility genes were not identified [gag, pol, and env retroviral genes regions in a correlated dose-dependent manner, supporting the activation of proviral forms of HERV-K [An increased expression of the primate specific ERV-K family in a subgroup of sALS patients was reported in at least two studies ,141, andentified . Expressentified . In the Mechanistically, the knockdown of endogenous TDP-43 with siRNA reduced HERV-K expression, thus arguing against a derepression of a HERV-K copy (or copies) caused by overexpression-mediated nuclear depletion of TDP-43 in the neurons of these patients or in vitro. In addition, ChIP assays, together with in vitro luciferase assays on the HERV-K LTR in HeLa cells, confirmed the activating effects of TDP-43 load and binding onto the LTR . FurtherHeterochromatic regions are typically enriched for different types of intergenic repeats and depleted from genes. In agreement, the loss of heterochromatin identified in post-mortem human ALS brain nuclei without TDP-43 by Liu and colleagues via ATAC-seq was enriched for a particular class of interspersed intergenic repeat, i.e., the LINE1 elements . ImportaThese results suggest that there may be an accumulation of LINE1 nucleic acids in TDP-43-negative nuclei, which can potentially increase LINE1 DNA content, even in the absence of complete retrotransposition leading to truncated L1 . IncreasL1 RNA was shown to negatively regulate the enzymatic activity of the H3K9me3 SUV39H1, thus sustaining heterochromatin loss [Therefore, in the brain of ALS patients, TDP-43 alterations may lead to LINE-1 reactivation via H3K9me3 reduction and chromatin decondensation, but in some instances, they could also be directly linked to the increase in L1 new copies integrated into the neurons genome. It is interesting to stress that in another pathological condition, i.e., a mouse model of progeria, tin loss . A schemDcr-2 mRNA and protein, regulating both its levels and activity [Flies have often represented a good model for TDP-43 deregulation and ALS. For this reason, TDP-43 impact on TE was recently examined  has also been demonstrated to be effective in partially reverting the locomotion defects in TDPH-deficient flies induced by RTEs activation, with azidotimidine been the most efficient. Enotaxin, a compound capable of activating the siRNA pathway and able to counteract RTE activation, was also able to restore the locomotive behaviors and the formation of neuromuscular synapsis .Naturally occurring splice variant isoforms of TDP-43 leading to shorter TDP-43 proteins have been revealed on several occasions since the early 2000s ,157, butAcrv1 gene regulation by TDP-43, the author identified several RNA isoforms of mTDP-43 in testicular tissue [Acrv1 promoter in GC-2 cells or minimal c-fos promoter in HeLa cells, these variants were able, like the TDP-43 FL, to repress their expression [For example, in the study on the r tissue . These Tr tissue . When prpression  , a result that is in accordance with the lack of the glycine reach C-term region . Their pAnother intriguing finding of the work performed by Giannini and colleagues is the presence of the TDP-35 form at chromatin at R-loop, as highlighted by co-IP in both whole-cell lysates and chromatin fractions of lymphoblastoid cell lines (LCL). Regarding the importance of TDP-43 disease-associated mutations, it is interesting to note that this interaction was higher in for LCL carrying the A382T mutation of TDP-43 .2+-activated calpain cleavage produces N-term fragments identified to be of about 36, 34, and 32 kDa [Malat-1 lncRNA binding to TDP-43 in the nucleus [The authors initially understood TDP-35 to correspond to CTF35, a C-terminal fragment of 35 kDA, resulting from the truncation TDP-43  using and 32 kDa . Anotherd 32 kDa . Notablyd 32 kDa ,163. Thid 32 kDa  could be nucleus . In any  nucleus . Finally nucleus ,159 or t nucleus . Indeed,TARDBP mutations have been identified mostly in familial ALS patients but also in sporadic FTD, AD, and PD cases, and more than 50 TDP-43 variants have been linked to the incidence of ALS/FTD ,166. TheFew TDP-43 models carrying null or point mutations have been investigated to explore the association of pathological TDP with altered epigenetics treats. We have reported them in the previous sections in relation to their impact on chromatin in their dedicated sections. In the present paragraph, we condense the impact of TDP-43 mutations on chromatin homeostasis from a mutation point of view. Acrv1 promoter [CHOP transcriptional activation [Depending on the regions hinted by mutations, different scenarios on chromatin impact can be envisaged. Indeed, mutations in the C-term—known to guide nuclear loss—are expected to have a broad impact on TDP-43 functions both at the RNA and the DNA levels. This might naturally hold true for mutations within the NLS or the NES controlling the nucleocytoplasmic shuttling. Instead, mutations in the N-term, whether at the RRM1 or RRM2, may have a more focalized impact on the RNA-processing aspect or on chromatin, whether linked to RNA processing aspects or lncRNA-related functions of TDP-43 on chromatin, but also on TDP-43′s ability to bind ssDNA or dsDNA, as has been documented in different studies ,20,21,22promoter  and on ipromoter . In additivation . Insteadtivation . Expresstivation ,64) convAll ALS/FTD TDP-43 mutations reported to date to have an impact on chromatin are concentrated in the C-term region and lead to either a defect in DNA methylation or DNA damage or to both, and some also impact TDP-43 own regulation .Finally, as we detail further in the next section  with different susceptibility according to the cell type and/or differentiation stage ,159,160 y SUP-46 . In party SUP-46 . SUP-46 y SUP-46 ,182. TheOne thing that can be said, however, is that the TDP-43 isoforms appear comparatively much less expressed than TDP-43 FL mRNA in human iNeurons and WT mouse cortex . HoweverTARDBP transcripts, sTDP43-1 and sTDP43-2 splice events were found to be highly enriched in lumbar motor neurons, reaching 17% and 22% of total TARDBP transcripts, respectively. In the human, by re-examining available RNA-seq data, the authors consistently observed significant expression of sTDP43-1 but not sTDP43-2 in several different regions of the CNS, including but not limited to the spinal cord ventral horn, spinal motor neurons, cerebellum, and frontal cortex, making from 30% up to 55% of the TARBDP transcripts. In the lumbar motor neurons, sTDP43-1 even reached almost 70% of the total transcripts against less than 10% of TDP-43 mRNA. Lumbar glial cells also contained significant amounts of the isoform proteins. No significant differences between control, sALS, and C9ALS  patient samples were identified [Thus, in mouse, compared to frontal cortex homogenate where they contribute around 1% of entified . These dentified . In addientified . As for Although TDP-43 is ubiquitously expressed and can regulate/maintain its own expression through the negative feedback loop discussed above, some observations suggest that its overall expression level is not frozen but can also experience regulated variations in time and space. In particular, each tissue has its specific amount of TDP-43, and these are adequately compensated in Tardbp +/− mice in physiological condition . In addiThus, regulation of its expression might also occur at a more classical transcriptional level through its promoter. While the mechanisms of it auto-regulation by splicing and NMD decay have been the focus of many efforts, the promoter features have been less intensively investigated until the last two years ,173,186.In 2009, prediction of the TARDBP promoter identified a bipartite promoter made from the about 500 bp before the exon1 TSS and two regions within the intron1 . From a ChIP-seq tracks from the UCSC Genome Browser show that the histone mark H3K4me3, the enrichment of which marks active promoter regions, is indeed found from upstream exon 1 (TSS) down to exon 2 in the human cortex  and in oThe TSS of TDP-43 FL NM_007374.4 results as the main TSS , but adChIP analyses in HEK293T cells revealed that TDP-43 binds to its own upstream-and intron1 bipartite promoter . SpecifiIn parallel, hnRNP-K, another hnRNP, was shown to bind to the TARDBP promoter, most probably at its predicted i-motif located upstream (at −371_−309) of the reference TSS, which represents a motif particularly well-conserved between human and mice. At the functional level, hnRNP-K binds to TARDBP promoter and appears to act as a dose-dependent activator of transcription in luciferase assays , possiblIn addition, the upstream promoter region of TARDBP appears to drive high transcriptional activity in cell lines of neuronal origin and in HeLa when compared to the non-neural human embryonic kidney 293 cells , suggestIn the 2009 study, non-coding DNA variants investigated in the upstream promoter or intron 1 region of the TARDBP gene were detected quite frequently (35%) in the brain  of sALS patients (16/46), including two promoter variants found more frequently in sALS patients than in controls . These dTardbp mRNA and TDP-43 expression as observed in normal aging mice in muscle and brain. It is therefore probable that similar epigenetic modifications modulate the expression of human TARDBP locus . In addition, no such epigenetic changes were noted in the liver, suggesting some tissue-specific susceptibility [A second potential line of regulation of TDP-43 transcription involves epigenetic modifications. Specifically, DNA methylation at CpGs has been found to be important for TDP-43 nonsense-mediated decay-isoform production and autoregulation, as reported above. In addition, CpG methylation is well known to regulate gene expression at promoter regulatory regions. The human TARDBP holds a large CpG island with at least three CpG clusters along upstream-intron1 bipartite promoter, accounting for 123 CpG ,186. In The treatment for ALS involves the multidisciplinary management of symptoms and the use of drugs, principally neuroprotective, neurotrophic, anti-inflammatory, antioxidative, and anti-glutamatergic drugs . Many efClinicalTrials.gov Identifier: NCT05193994). Here, it is important also to underline that, apart from the ARV effect on HERV-K, lamivudine is also a well-known inhibitor of the LINE-1 retrotransposition [Alongside TDP-43 itself, the many studies reported in this review also open routes to new targets for treatment, notably pharmacologic inhibition of retrotransposons, even in the absence of overt retrotransposition, or endogenous retroviruses proteins. In particular, inhibition of the HERV-K family env protein may mitigate the neurotoxic effects and/or spreading of TDP-43 pathology. The therapeutic use of an antiretroviral (ARV) cocktail has already been explored to some extent. Some HIV-infected patients develop ALS-like symptoms (HALS) , maybe lposition , widely ClinicalTrials.gov identifiers: NCT03574428 and NCT03179423) [HERV-K env glycoprotein, when produced in the diseased cells, should be directed to the cell plasma membrane and exposed at the surface. Indeed, focal accumulations of HERV-K env at the cell membrane of cortical neurons and motor neurons in the lumbar spinal cord have been evidenced in some ALS patients . Thus, i3179423) ,203).Epigenetic modifications do not modify the DNA sequence but are generally stable. Many are reversible, and pathological TDP-43-related modifications, either caused by TDP-43 or causing TDP-43 alterations, could constitute a new era of therapeutic target investigations for TDP-43 proteinopathies. Targeted delivery of molecules modulating the toxic impact of TDP-43 alterations, such as the ones presented in the first paragraph on chromatin modifiers, could represent a path for new therapies and could, notably, benefit from novel pharmacological approaches derived from research against cancer .C9orf72 repeat expansion in patients-derived iPSCs and the promoter of the APP protein involved in Alzheimer’s disease in HEK293T. The manipulation of DNA methylation notably employed HDR, not NEHJ [Moreover, a more meticulous investigation on functions and targets specifically related to the short protein isoforms of TDP-43 on chromatin would bring further insight to the TDP-43/TARDBP pathologies and onset. Furthermore, it will bring a deeper understanding of TARDBP gene regulation and isoforms modulations, hopefully providing reliable future directions for new therapies. In particular, targeted manipulation of the DNA methylation status of the TARDBP 3′UTR could represent another way of correcting TDP-43 autoregulation. Technologies using dCas9-DNMT3a fusion protein constructs can direct specific on-site targeting of DNMT3a by accurately designing guide RNAs , or the not NEHJ ; thus, inot NEHJ . AlthougIn this review, we have emphasized the broad role of TDP-43 in the chromatin context, and, conversely, the potential role that could be played by the epigenetics on its own regulation. The results of all these studies show that TDP-43  has many interconnections with chromatin and can profoundly impact chromatin homeostasis and gene expression through a range of different modalities. TDP-43 thus appears to be a pleiotrophic protein whose perturbation alters a wide variety of crucial cellular functions. It is important to state that most of the reported works have been performed on cellular models or on brain samples from ALS and FTD–ALS patients post-mortem. Therefore, we still lack confirmation in advanced disease models and in human early disease stages. Gaining information at earlier stages could presumably allow us to identify some targets as early biomarkers. In addition, as described in the introduction, ALS and FTD–ALS are not the unique neurodegenerative contexts in which TDP-43 abnormalities are observed. Notably, TDP-43 abnormalities in LATE, Alzheimer’s and Huntington’s diseases and brains after traumatic brain injury (TBI) have already been well described. However, TDP-43 inclusions are now shown to appear in a large panel of neurological and muscular disorders, as presented in a recent review . TherefoAttention must also be drawn to the diversity of the lncRNAs interacting with TDP-43. We reported a variety of them, which we discussed in relation to the process in which their functional interaction with TDP-43 has been shown. However, we limited our review to the processes with a direct impact on chromatin: either chromatin eviction or targeting for transcriptional regulation, or else for DNA repair. Still, it is worth underlining that TDP-43 interaction with at least two other lncRNAs has been described, namely. NEAT1 long isoform (NEAT1_2) and LCETRL3. NEAT1 promotes TDP-43 inclusion in NEAT1 nuclear paraspeckles by liquid–liquid phase separation in case of stress, forming protective nuclear bodies . The proQ331K knock-in mouse reported weight gain and age-dependent increases in food intake and a generally intact innate exploratory digging behavior in the mutant female compare to the male [An additional factor to be considered in TDP-43-linked pathologies is the role that gender has in the prognosis of ALS-FTD. Population-based datasets have highlighted a male prevalence of ALS cases with a 2:1 gender ratio , althougthe male . Thus, fFinally, the new technological possibilities enabling single-cell analysis or TDP-43 nuclear loss-based differential sorting appear crucial. Such cell partitioning can be used for single or multi-omic data analysis, for example, such as in transcription, DNA methylation, or chromatin accessibility , to idenSources specific to the epigenetic aspects regarding TDP-43 for this review were identified via PubMed searches using the key terms “TDP-43”, “TDP43”, or “TARDBP” AND the epigenetic features “DNA methylation”, “Methylation ”, “Chromatin”, “Chromatin associated”, or “Epigenetics”, or the RNA/DNA elements “lncRNA ”, “miRNA”, “Retrotransposons”, or technical methods “ChIP”, “RIP”, “RNA-IP”, or “ATAC-seq”. No time limitation was applied (up to July 2023), with the aim of covering the thematic of the review as exhaustively as possible, including its implication for neurodegenerative pathologies. Additional sources were taken from the references used in the above-retained research or review articles and from the publications already known by the authors. No bias was assigned for authors or institutions. Manual curation was performed to remove protein post-translational modifications  not directly linked to TDP-43 epigenetic regulation. Likewise, resources treating the implication of TDP-43 in RNA splicing with no clear consequences for epigenetic processes or in miRNA processing were not included as they were already covered by other recent reviews. When a review was used as a resource, it was cited in the text.