Molecular Dynamic Simulation Study on Replacement of Methane Hydrates with Carbon Dioxide Under Different Temperatures, Pressures, and Concentrations of Ethylene Glycol.

In order to alleviate the world energy resources crisis, the research and development of natural gas hydrates has a very important economic value and strategic significance. The CH4-CO2 replacement method can not only achieve geological storage of carbon dioxide but also more effectively mine natural gas hydrates. Based on molecular dynamics theory and the properties of natural gas hydrates, this paper delves into the replacement of methane hydrate with carbon dioxide under different temperatures, pressures, and concentrations of ethylene glycol (EG). We established a CO2-Hydrate model and three CO2/EG-Hydrate models with different concentrations of EG, and we simulated the radial distribution function (RDF), mean square displacement (MSD), and relative density distribution of each particle in the system in different conditions. The higher the temperature, the more unstable the methane hydrates are, and the methane hydrates are more prone to decomposition. Compared with 280 and 290 K, the temperature of 270 K is more favorable for carbon dioxide molecules to enter the hydrate layer and form carbon dioxide hydrates. The changes in pressure have little impact on the decomposition of methane hydrates, the rupture of water cages of methane hydrates, and the number of carbon dioxide molecules entering the hydrate layer under temperatures of 280 K and pressures of 1, 4, and 7 MPa. But overall, a pressure of 1 MPa is more conducive for carbon dioxide molecules to enter the hydrate layer and form carbon dioxide hydrates. Adding EG to CO2 molecules can inhibit the decomposition of methane hydrates. However, the higher the concentration of EG, the faster the decomposition of methane hydrates. The degree of fracture of the water cages in methane hydrates is greater under pure CO2 conditions. Adding EG to CO2 molecules is more conducive for CO2 molecules to enter the hydrate layer and form carbon dioxide hydrates. This review is of great significance to improve the mining efficiency and CO2 storage efficiency of the replacement of natural gas hydrates with CO2.

Rapid and Complete Digestion of Refractory Geological Samples Using Ultrafine Powder for Accurate Analyses of Trace Elements.

Complete sample digestion is a prerequisite for acquiring high-quality analytical results for geological samples. Closed-vessel acid digestion (bomb) has typically been used for the total digestion of refractory geological samples. However, the long digestion time (4-5 days) and insoluble fluoride complexes still pose challenges for digesting refractory geological samples using this approach. In this study, an efficient and simplified digestion technique combining ultrafine powders from planetary ball milling with bomb digestion was developed for trace element analysis of refractory geological samples: peridotite and granitoid. The method shows two significant improvements compared with previous approaches. (1) By performing dry planetary ultrafine milling, the initial 200 mesh peridotite (<74 µm) could be reduced to 800 mesh (<20 µm) in 6 min at a ball-to-powder mass ratio of approximately 15 using 3 mm tungsten carbide milling balls. (2) Complete peridotite and granitoid dissolution were achieved in approximately 2 h, 60 times faster than what is achievable using previous methods (2 h vs 120 h). Moreover, ultrafine powders effectively suppressed insoluble fluoride formation during bomb digestion. A suite of peridotite and granitoid reference materials were measured to evaluate the stability of this method. This efficient, simple, and reliable sample digestion method could benefit geological, food, environmental, and other fields requiring solid sample decomposition via wet acid, fusion, combustion, or dry ashing.

Ubiquitin-specific proteinase 1 stabilizes PRRSV nonstructural protein Nsp1ß to promote viral replication by regulating K48 ubiquitination.

The porcine reproductive and respiratory syndrome virus (PRRSV) can lead to severe reproductive problems in sows, pneumonia in weaned piglets, and increased mortality, significantly negatively impacting the economy. Post-translational changes are essential for the host-dependent replication and long-term infection of PRRSV. Uncertainty surrounds the function of the ubiquitin network in PRRSV infection. Here, we screened 10 deubiquitinating enzyme inhibitors and found that the ubiquitin-specific proteinase 1 (USP1) inhibitor ML323 significantly inhibited PRRSV replication in vitro. Importantly, we found that USP1 interacts with nonstructural protein 1ß (Nsp1ß) and deubiquitinates its K48 to increase protein stability, thereby improving PRRSV replication and viral titer. Among them, lysine at position 45 is essential for Nsp1ß protein stability. In addition, deficiency of USP1 significantly reduced viral replication. Moreover, ML323 loses antagonism to PRRSV rSD16-K45R. This study reveals the mechanism by which PRRSV recruits the host factor USP1 to promote viral replication, providing a new target for PRRSV defense.IMPORTANCEDeubiquitinating enzymes are critical factors in regulating host innate immunity. The porcine reproductive and respiratory syndrome virus (PRRSV) nonstructural protein 1ß (Nsp1ß) is essential for producing viral subgenomic mRNA and controlling the host immune system. The host inhibits PRRSV proliferation by ubiquitinating Nsp1ß, and conversely, PRRSV recruits the host protein ubiquitin-specific proteinase 1 (USP1) to remove this restriction. Our results demonstrate the binding of USP1 to Nsp1ß, revealing a balance of antagonism between PRRSV and the host. Our research identifies a brand-new PRRSV escape mechanism from the immune response.

Accelerated and Biopredictive In Vitro Release Testing Strategy for Single Agent and Combination Long-Acting Injectables.

The purpose of this study was to develop an in vitro release testing (IVRT) strategy to predict the pre-clinical performance of single agent and combination long acting injectable (LAI) suspension products. Two accelerated IVRT methods were developed using USP apparatus 2 to characterize initial, intermediate, and terminal phases of drug release. Initial and intermediate phases were captured using a suspension cup with moderate agitation to ensure a constant, low surface area exposure of the LAI suspension to the release media. The terminal phase was obtained by exposing the LAI suspension to a high initial paddle speed. This resulted in smaller suspension particulates with high cumulative surface area that were dispersed throughout the release media, enabling rapid drug release. The in vitro release profiles obtained with these two methods in 48 h or less were independently time scaled to reflect the in vivo time scale of approximately 1800 h. Level-A in vitro in vivo correlations (IVIVCs) were separately developed for each method and active pharmaceutical ingredient (API) using in vivo absorption profiles obtained by deconvolution of rat plasma concentration-time profiles. The IVIVCs were successfully validated for each API. This work provides a framework for evaluating individual phases of drug release of complex LAIs to ultimately predict their in vivo performance.

Space-time cube uncovers spatiotemporal patterns of basin ecological quality and their relationship with water eutrophication.

Maintaining an optimal eco-environment is important for sustainable regional development. However, existing methods are inadequate for examining both spatial and temporal dimensions. Here, we propose a systematic procedure for spatiotemporal examination of the eco-environment using the space-time cube (STC) model and describe a preliminary investigation of the coupling relationships between basin ecological quality and water eutrophication in upstream of the Han River basin between 2000 and 2020. The STC model considers the temporal dimension as the third dimension in calculations. We first categorized the basin into three sub-watershed types: forest, cultivated land, and artificial surface. Subsequently, the ecological quality and driving factors were assessed and identified using the remote sensing ecological index (RSEI) and Geodetector method, respectively. The findings indicated that the forest basin and artificial surface basin had the highest and lowest ecological quality, respectively. The spatiotemporal cold spots of ecological quality during the past 20 years were mostly located in the vicinity of reservoirs, rivers, and artificial surface areas. Human activity, precipitation, and the percentage of cultivated land were other important driving factors in the artificial surface, forest, and cultivated land sub-watersheds, respectively, in addition to the dominant factors of elevation and temperature. The results also indicated that when the ecological quality degraded to a certain extent, water eutrophication was significantly coupled with the ecological quality of the catchments. The findings of this study are useful for ecological restoration and sustainable river basin development.

Preparation and epitope mapping of monoclonal antibodies against African swine fever virus p22 protein.

African swine fever (ASF), caused by the African swine fever virus (ASFV), is now widespread in many countries and severely affects the commercial rearing of swine. Rapid and early diagnosis is crucial for the prevention of ASF. ASFV mature virions comprise the inner envelope protein, p22, making it an excellent candidate for the serological diagnosis and surveillance of ASF. In this study, the prokaryotic-expressed p22 recombinant protein was prepared and purified for immunization in mice. Four monoclonal antibodies (mAbs) were identified using hybridoma cell fusion, clone purification, and immunological assays. The epitopes of mAbs 14G1 and 22D8 were further defined by alanine-scanning mutagenesis. Our results showed that amino acids C39, K40, V41, D42, C45, G48, E49, and C51 directly bound to 14G1, while the key amino acid epitope for 22D8 included K161, Y162, G163, D165, H166, I167, and I168. Homologous and structural analysis revealed that these sites were highly conserved across Asian and European ASFV strains, and the amino acids identified were located on the surface of p22. Thus, our study contributes to a better understanding of the antigenicity of the ASFV p22 protein, and the results could facilitate the prevention and control of ASF.

RhoA suppresses pseudorabies virus replication in vitro.

The porcine pseudorabies virus (PRV) is one of the most devastating pathogens and brings great economic losses to the swine industry worldwide. Viruses are intracellular parasites that have evolved numerous strategies to subvert and utilize different host processes for their life cycle. Among the different systems of the host cell, the cytoskeleton is one of the most important which not only facilitate viral invasion and spread into neighboring cells, but also help viruses to evade the host immune system. RhoA is a key regulator of cytoskeleton system that may participate in virus infection. In this study, we characterized the function of RhoA in the PRV replication by chemical drugs treatment, gene knockdown and gene over-expression strategy. Inhibition of RhoA by specific inhibitor and gene knockdown promoted PRV proliferation. On the contrary, overexpression of RhoA or activation of RhoA by chemical drug inhibited PRV infection. Besides, our data demonstrated that PRV infection induced the disruption of actin stress fiber, which was consistent with previous report. In turn, the actin specific inhibitor cytochalasin D markedly disrupted the normal fibrous structure of intracellular actin cytoskeleton and decreased the PRV replication, suggesting that actin cytoskeleton polymerization contributed to PRV replication in vitro. In summary, our data displayed that RhoA was a host restriction factor that inhibited PRV replication, which may deepen our understanding the pathogenesis of PRV and provide further insight into the prevention of PRV infection and the development of anti-viral drugs.

Fragmentation of continental subduction is ending the Himalayan orogeny.

After two continents collide, plate convergence and orogenesis are sustained because subducted continental lithosphere continues pulling the surface plate. It remains controversial how, why, and when continental plate convergence and collision slow down and eventually cease. We use an unprecedented data coverage and present a regional-scale seismic tomographic image of the mantle structure beneath the Tibetan Plateau. In the mantle transition zone, we identify multiple high-velocity anomalies and interpret them as detached pieces of the Indian continental slab. Facilitated by internal heterogeneity of the continental lithosphere, piecewise slab detachments could reduce the slab pull force, resulting in the Miocene slowdown of the India-Eurasia convergence and coeval diachronous potassic volcanism in southern Tibet. We propose that slab detachment is a mechanism that eventually will lead to the end of the Indo-Eurasian continental collision and the Himalayan orogeny.

Genomic analysis of almost 8,000 Salmonella genomes reveals drivers and landscape of antimicrobial resistance in China.

IMPORTANCE: We established the largest Salmonella genome database from China and presented the landscape and spatiotemporal dynamics of antimicrobial resistance genes. We also found that economic, climatic, and social factors can drive the rise of antimicrobial resistance. The Chinese local Salmonella genome database version 2 was released as an open-access database (https://nmdc.cn/clsgdbv2) and thus can assist surveillance studies across the globe. This database will help inform interventions for AMR, food safety, and public health.

Effects of environmental factors on the river water quality on the Tibetan Plateau: a case study of the Xoirong River, China.

Climate, topography, and landscape patterns affect river water quality through processes that influence non-point source pollution. However, little is known about the response of the water quality of rivers on China's Tibetan Plateau to these environmental factors. Based on the water quality parameters data of the Xoirong River on the Tibetan Plateau in western China, the redundancy analysis and variation partitioning analysis were adopted to determine the main influencing factors affecting river water quality and their spatial scale effects. The major water pollutants were further analyzed using the partial least square-structural equation modeling (PLS-SEM). Another mountainous river with a similar latitude, the same stream order, and low anthropogenic disturbance in central China, the Jinshui River, was also selected for comparative discussion. The results indicated that the overall river water quality on the Tibetan Plateau was superior to that of the Jinshui River. At the catchment scale, the cumulative explanatory powers of the influencing factors of both rivers were greatest. Landscape composition and configuration were the determinant factors for the overall water quality of the two rivers, while the river on the Tibetan Plateau was also significantly affected by climatic and topographical factors. Regarding the main water quality issue, i.e., total nitrogen, agricultural production activities might be the main cause of the river on the Tibetan Plateau. This study unveiled that the river water quality on the Tibetan Plateau is sensitive to climate and topography through comparative studies.

GID complex regulates the differentiation of neural stem cells by destabilizing TET2.

Brain development requires a delicate balance between self-renewal and differentiation in neural stem cells (NSC), which rely on the precise regulation of gene expression. Ten-eleven translocation 2 (TET2) modulates gene expression by the hydroxymethylation of 5-methylcytosine in DNA as an important epigenetic factor and participates in the neuronal differentiation. Yet, the regulation of TET2 in the process of neuronal differentiation remains unknown. Here, the protein level of TET2 was reduced by the ubiquitin-proteasome pathway during NSC differentiation, in contrast to mRNA level. We identified that TET2 physically interacts with the core subunits of the glucose-induced degradation-deficient (GID) ubiquitin ligase complex, an evolutionarily conserved ubiquitin ligase complex and is ubiquitinated by itself. The protein levels of GID complex subunits increased reciprocally with TET2 level upon NSC differentiation. The silencing of the core subunits of the GID complex, including WDR26 and ARMC8, attenuated the ubiquitination and degradation of TET2, increased the global 5-hydroxymethylcytosine levels, and promoted the differentiation of the NSC. TET2 level increased in the brain of the Wdr26+/- mice. Our results illustrated that the GID complex negatively regulates TET2 protein stability, further modulates NSC differentiation, and represents a novel regulatory mechanism involved in brain development.

Utilization of deep neuromuscular blockade combined with reduced abdominal pressure in laparoscopic radical gastrectomy for gastric cancer: An academic perspective.

BACKGROUND: Few studies have examined the specific efficacy of deep neuromuscular blockade (NMB) combined with pneumoperitoneal pressure reduction in laparoscopic radical gastrectomy (LRG) in the elderly. AIM: To investigate the application effect of deep neuromuscular blockade (NMB) combined with reduced pneumoperitoneum pressure in LRG for gastric cancer (GC) in elderly patients and its influence on inflammation. METHODS: Totally 103 elderly patients with GC treated in our hospital between January 2020 and January 2022 were retrospectively analyzed. Among them, 45 patients treated with surgery based on deep NMB and conventional pneumoperitoneum pressure were assigned to the control group, while the rest of the 58 patients who underwent surgery based on deep NMB and reduced pneumoperitoneum pressure were assigned to the observation group. The two groups were compared in the changes of the Leiden-surgical rating scale score, serum tumor necrosis fact-α (TNF-α) and interleukin 6 (IL-6) before and after therapy. The visual analogue scale (VAS) was adopted for evaluating the shoulder pain of patients at 8 h, 24 h and 48 h after the operation. The driving pressure of the two groups at different time points was also compared. Additionally, the operation time, pneumoperitoneum time, infusion volume, blood loss, extubation time after surgery, residence time in the resuscitation room, TOF% = 90% time and post-anesthetic recovery room (PACU) stay time were all recorded, and adverse PACU-associated respiratory events were also recorded. The postoperative hospitalization time and postoperative expenses of the two groups were counted and compared. RESULTS: No significant difference was found between the two groups at the time of skin incision, 60 minutes since the operation and abdominal closure after surgery (P > 0.05). The observation group exhibited significantly lower VAS scores than the control group at 24 and 48h after surgery (P < 0.05). Additionally, the observation group had significantly lower driving pressure than the control group at 5 min and 60 min after the establishment of pneumoperitoneum (P < 0.05). Additionally, the two groups were similar in terms of the operation time, pneumoperitoneum time, infusion volume, blood loss, extubation time after surgery, residence time in the resuscitation room and TOF% = 90% time (P > 0.05), and the observation group showed significantly lower TNF-α and IL-6 Levels than the control group at 24 h after therapy (P < 0.05). Moreover, the incidence of adverse events was not significantly different between the two groups (P > 0.05), and the observation group experienced significantly less hospitalization time and postoperative expenses than the control group (P < 0.05). CONCLUSION: Deep NMB combined with reduced pneumoperitoneum pressure can decrease the VAS score of shoulder pain and inflammatory reaction, without hindering the surgical vision and increasing adverse PACU-associated respiratory events, and can thus shorten the hospitalization time and treatment cost for patient.

Cross-Subject Transfer Method Based on Domain Generalization for Facilitating Calibration of SSVEP-Based BCIs.

In steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs), various spatial filtering methods based on individual calibration data have been proposed to alleviate the interference of spontaneous activities in SSVEP signals for enhancing the SSVEP detection performance. However, the time-consuming calibration session would increase the visual fatigue of subjects and reduce the usability of the BCI system. The key idea of this study is to propose a cross-subject transfer method based on domain generalization, which transfers the domain-invariant spatial filters and templates learned from source subjects to the target subject with no access to the EEG data from the target subject. The transferred spatial filters and templates are obtained by maximizing the intra- and inter-subject correlations using the SSVEP data corresponding to the target and its neighboring stimuli. For SSVEP detection of the target subject, four types of correlation coefficients are calculated to construct the feature vector. Experimental results estimated with three SSVEP datasets show that the proposed cross-subject transfer method improves the SSVEP detection performance compared to state-of-art methods. The satisfactory results demonstrate that the proposed method provides an effective transfer learning strategy requiring no tedious data collection process for new users, holding the potential of promoting practical applications of SSVEP-based BCI.

The African swine fever virus I10L protein inhibits the NF-κB signaling pathway by targeting IKKß.

Proinflammatory factors play important roles in the pathogenesis of African swine fever virus (ASFV), which is the causative agent of African swine fever (ASF), a highly contagious and severe hemorrhagic disease. Efforts in the prevention and treatment of ASF have been severely hindered by knowledge gaps in viral proteins responsible for modulating host antiviral responses. In this study, we identified the I10L protein (pI10L) of ASFV as a potential inhibitor of the TNF-α- and IL-1ß-triggered NF-κB signaling pathway, the most canonical and important part of host inflammatory responses. The ectopically expressed pI10L remarkably suppressed the activation of NF-κB signaling in HEK293T and PK-15 cells. The ASFV mutant lacking the I10L gene (ASFVΔI10L) induced higher levels of proinflammatory cytokines production in primary porcine alveolar macrophages (PAMs) compared with its parental ASFV HLJ/2018 strain (ASFVWT). Mechanistic studies suggest that pI10L inhibits IKKß phosphorylation by reducing the K63-linked ubiquitination of NEMO, which is necessary for the activation of IKKß. Morever, pI10L interacts with the kinase domain of IKKß through its N-terminus, and consequently blocks the association of IKKß with its substrates IκBα and p65, leading to reduced phosphorylation. In addition, the nuclear translocation efficiency of p65 was also altered by pI10L. Further biochemical evidence supported that the amino acids 1-102 on pI10L were essential for the pI10L-mediated suppression of the NF-κB signaling pathway. The present study clarifies the immunosuppressive activity of pI10L, and provides novel insights into the understanding of ASFV pathobiology and the development of vaccines against ASF. IMPORTANCE African swine fever (ASF), caused by the African swine fever virus (ASFV), is now widespread in many countries and severely affects the commercial rearing of swine. To date, few safe and effective vaccines or antiviral strategies have been marketed due to large gaps in knowledge regarding ASFV pathobiology and immune evasion mechanisms. In this study, we deciphered the important role of the ASFV-encoded I10L protein in the TNF-α-/IL-1ß-triggered NF-κB signaling pathway. This study provides novel insights into the pathogenesis of ASFV and thus contributes to the development of vaccines against ASF.

Tet2 acts in the lateral habenula to regulate social preference in mice.

The lateral habenula (LHb) has been considered a moderator of social behaviors. However, it remains unknown how LHb regulates social interaction. Here, we show that the hydroxymethylase Tet2 is highly expressed in the LHb. Tet2 conditional knockout (cKO) mice exhibit impaired social preference; however, replenishing Tet2 in the LHb rescues social preference impairment in Tet2 cKO mice. Tet2 cKO alters DNA hydroxymethylation (5hmC) modifications in genes that are related to neuronal functions, as is confirmed by miniature two-photon microscopy data. Further, Tet2 knockdown in the glutamatergic neurons of LHb causes impaired social behaviors, but the inhibition of glutamatergic excitability restores social preference. Mechanistically, we identify that Tet2 deficiency reduces 5hmC modifications on the Sh3rf2 promoter and Sh3rf2 mRNA expression. Interestingly, Sh3rf2 overexpression in the LHb rescues social preference in Tet2 cKO mice. Therefore, Tet2 in the LHb may be a potential therapeutic target for social behavior deficit-related disorders such as autism.

Evaluating the global, regional, and national impact of syphilis: results from the global burden of disease study 2019.

Syphilis is a global public health concern. This study aimed to assess the global and regional burden of syphilis from 1990 to 2019. Disease burden was evaluated using disability-adjusted life-years (DALYs) and prevalence. Data were extracted from the 2019 global burden of disease Study, an open database available for download. Age-standardized rates (ASR) and estimated annual percentage changes (EAPC) were calculated to evaluate the syphilis burden over time. In 2019, the total number of prevalent cases of syphilis was 49.71 million worldwide. The ASR of prevalence was stable from 1990 to 2019 with an EAPC of 0.00 (95% CI - 0.10-0.11). The number of DALYs caused by syphilis was 7.36 million in 2019, reflecting a reduction of 16.38% compared with that in 1990 (8.80 million). The ASR of DALYs exhibited a decreasing trend from 1990 to 2019 (EAPC = - 1.01; 95% CI - 1.19 to - 0.84), with the highest rates observed in the younger age group (< 14 years old). In 2019, the highest ASR of DALYs was found in low sociodemographic index (SDI) regions (239.21/100,000), and the lowest in high SDI regions (3.14/100,000). Generally, the ASR of DALYs decreased as the SDI increased. The top three countries with the highest ASR of DALYs for syphilis were the Solomon Islands, Equatorial Guinea, and Liberia. While the global prevalence of syphilis remained persistently high from 1990 to 2019, there has been a recent decrease in the ASR of DALYs. Increased attention should be dedicated to younger populations and regions characterized by low SDIs.

Nucleus Pulposus Cells Induce M2 Polarization of RAW264.7 via CX3CL1/CX3CR1 Pathway and M2 Macrophages Promote Proliferation and Anabolism of Nucleus Pulposus Cells.

Background: The mechanisms underlying M2 macrophage polarization induced by nucleus pulposus (NP) cells are unclear. The effects that M2-polarized macrophages have on NP cells are also controversial. Methods: Transcriptome sequencing was performed to detect the gene change profiles between NP cells from ruptured intervertebral disc (IVD) and normal IVD. The main difference on biological activities between the two cell groups were analyzed by GO analysis and KEGG analysis. Virus transduction, flow cytometry, immunofluorescence, RT-PCR, western blot, CCK-8, TUNEL staining, and AO/EB staining were performed to explore the interactions between NP cells and RAW264.7 macrophages. Statistics were performed using SPSS26. Results: 801 upregulated and 276 downregulated genes were identified in NP cells from ruptured IVD in mouse models. According to GO and KEGG analysis, we found that the differentially expressed genes (DEG) were dominantly enriched in inflammatory response, extracellular matrix degradation, blood vessel morphogenesis, immune effector process, ossification, chemokine signaling pathway, macrophage activation, etc. CX3CL1 was one of the top 20% DEG, and we confirmed that both NP tissue and cells expressed remarkably higher level of CX3CL1 in mouse models (p < 0.001∗). Besides, we further revealed that both the recombinant CX3CL1 and NP cells remarkably induced M2 polarization of RAW264.7 (p < 0.001∗), respectively, while this effect was significantly reversed by si-CX3CL1 or JMS-17-2 (p < 0.001∗). Furthermore, we found that M2 macrophages significantly decreased the apoptosis rate (p < 0.001∗) and the catabolic gene levels (p < 0.001∗) of NP cells, while increased the viability, proliferation as well as the anabolic gene levels of NP cells (p < 0.01∗). Conclusions: Via regulating CX3CL1/CX3CR1 pathway, NP cells can induce the M2 macrophage polarization. M2 polarized macrophages can further promote NP cell viability, proliferation, and anabolism, while inhibit NP cell apoptosis and catabolism.

5hmC modification regulates R-loop accumulation in response to stress.

R-loop, an RNA-DNA hybrid structure, arises as a transcriptional by-product and has been implicated in DNA damage and genomic instability when excessive R-loop is accumulated. Although previous study demonstrated that R-loop is associated with ten-eleven translocation (Tet) proteins, which oxidize 5-methylcytosine to 5-hydroxymethylcytosine (5hmC), the sixth base of DNA. However, the relationship between R-loop and DNA 5hmC modification remains unclear. In this study, we found that chronic restraint stress increased R-loop accumulation and decreased 5hmC modification in the prefrontal cortex (PFC) of the stressed mice. The increase of DNA 5hmC modification by vitamin C was accompanied with the decrease of R-loop levels; on the contrary, the decrease of DNA 5hmC modification by a small compound SC-1 increased the R-loop levels, indicating that 5hmC modification inversely regulates R-loop accumulation. Further, we showed that Tet deficiency-induced reduction of DNA 5hmC promoted R-loop accumulation. In addition, Tet proteins immunoprecipitated with Non-POU domain-containing octamer-binding (NONO) proteins. The deficiency of Tet proteins or NONO increased R-loop levels, but silencing Tet proteins and NONO did not further increase the increase accumulation, suggesting that NONO and Tet proteins formed a complex to inhibit R-loop formation. It was worth noting that NONO protein levels decreased in the PFC of stressed mice with R-loop accumulation. The administration of antidepressant fluoxetine to stressed mice increased NONO protein levels, and effectively decreased R-loop accumulation and DNA damage. In conclusion, we showed that DNA 5hmC modification negatively regulates R-loop accumulation by the NONO-Tet complex under stress. Our findings provide potential therapeutic targets for depression.

Role of regulatory T cells in spinal cord injury.

Spinal cord injury is an intricate process involving a series of multi-temporal and multi-component pathological events, among which inflammatory response is the core. Thus, it is crucial to find a way to prevent the damaging effects of the inflammatory response. The research has found that Treg cells can suppress the activation, proliferation, and effector functions of many parenchymal cells by multiple mechanisms. This review discusses how Treg cells regulate the inflammatory cells to promote spinal cord recovery. These parenchymal cells include macrophages/microglia, oligodendrocytes, astrocytes, and others. In addition, we discuss the adverse role of Treg cells, the status of treatment, and the prospects of cell-based therapies after spinal cord injury. In conclusion, this review provides an overview of the regulatory role of Treg cells in spinal cord injury. We hope to offer new insights into the treatment of spinal cord injury.

Identification of a Linear B Cell Epitope on p54 of African Swine Fever Virus Using Nanobodies as a Novel Tool.

African swine fever (ASF) has received great attention from the swine industry due to the pandemic and the lack of vaccines or effective treatments. In the present study, 13 African swine fever virus (ASFV) p54-specific nanobodies (Nbs) were successfully screened based on Bactrian camel immunization of p54 protein and phage display technology, and their reactivity with the p54 C-terminal domain (p54-CTD) was determined; however, only Nb8-horseradish peroxidase (Nb8-HRP) exhibited the best reactivity. Immunoperoxidase monolayer assay (IPMA) and immunofluorescence assay (IFA) results indicated that Nb8-HRP specifically reacted with ASFV-infected cells. Then, the possible epitopes of p54 were identified using Nb8-HRP. The results showed that Nb8-HRP could recognize p54-CTD truncated mutant p54-T1. Then, 6 overlapping peptides covering p54-T1 were synthesized to determine the possible epitopes. Dot blot and peptide-based enzyme-linked immunosorbent assay (ELISA) results suggested that one novel minimal linear B cell epitope, 76QQWVEV81, which had never been reported before, was identified. Alanine-scanning mutagenesis revealed that 76QQWV79 was the core binding site for Nb8. Epitope 76QQWVEV81 was highly conserved among genotype II ASFV strains and could react with inactivated ASFV antibody-positive serum from naturally infected pigs, indicating that it was a natural linear B cell epitope. These findings provide valuable insights for vaccine design and p54 as an effective diagnostic tool. IMPORTANCE The ASFV p54 protein plays an important role in inducing neutralization antibodies in vivo after viral infection and is often used as a candidate protein for subunit vaccine development. The full understanding of the p54 protein epitope provides a sufficient theoretical basis for p54 as a vaccine candidate protein. The present study uses a p54-specific nanobody as a probe to identify a highly conserved antigenic epitope, 76QQWVEV81, among different ASFV strains, and it can induce humoral immune responses in pigs. This is the first report using virus-specific nanobodies as a tool to identify some special epitopes that cannot be recognized by conventional monoclonal antibodies. This study opens up nanobodies as a new tool for identifying epitopes and also provides a theoretical basis for understanding p54-induced neutralizing antibodies.