1.Exploring Chemical Constituent Distribution in Blood/Brain(Hippocampus) and Emotional Regulatory Effect of Raw and Vinegar-processed Products of Citri Reticulatae Pericarpium Viride
Yi BAO ; Yonggui SONG ; Qianmin LI ; Zhifu AI ; Genhua ZHU ; Ming YANG ; Huanhua XU ; Qin ZHENG ; Yiting HUANG ; Zihan GAO ; Dan SU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):189-197
ObjectiveTo investigate the migration and distribution characteristics of chemical constituents in blood and hippocampal tissues before and after vinegar processing of Citri Reticulatae Pericarpium Viride(CRPV), and to explore the potential material basis and mechanisms underlying their regulatory effects on emotional disorders by comparing the effects of raw and vinegar-processed products of CRPV. MethodsUltra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) was employed to characterize and identify the chemical constituents of raw and vinegar-processed products of CRPV extracts, as well as their migrating components in blood and hippocampal tissues after oral administration. Reference standards, databases, and relevant literature were utilized for compound annotation, with data processing performed using PeakView 1.2 software. Seventy male C57BL/6 mice were randomly divided into seven groups, including the blank group, model group, diazepam group(2.5 mg·kg-1), raw CRPV low/high dose groups(0.6, 1.2 g·kg-1), and vinegar-processed CRPV low/high dose groups(0.6, 1.2 g·kg-1), with 10 mice per group. Except for the blank group, all other groups underwent chronic restraint stress(2 h·d-1) for 20 d. Each drug-treated group received oral administration at the predetermined dose starting 10 d after modeling, with a total treatment duration of 10 d. Following model-based drug administration, mice underwent open-field, forced swimming, and elevated plus maze tests. After anesthesia with isoflurane, whole brains were collected from each group of mice, and hippocampi were dissected. Reactive oxygen species(ROS) level in hippocampal tissues was quantified by enzyme-linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE) staining was used to observe hippocampal tissue morphology. Immunofluorescence was performed to detect neuronal nuclei(NeuN) and peroxisome proliferator-activated receptor alpha(PPARα) expressions in hippocampal tissue. Then, pharmacodynamic evaluations were conducted to assess the effects of raw and vinegar-processed CRPV on mood disorders, exploring the potential mechanisms. ResultsVinegar processing caused significant changes in the chemical composition of CRPV, with 18 components showing increased relative content and 35 components showing decreased relative content. The primary changes occurred in flavonoid compounds, including 20 flavonoids, 20 flavonoid glycosides, 3 triterpenes, 3 phenolic acids, 1 alkaloid, and 6 other compounds. Twenty-one components were detected in blood(15 methoxyflavones, 4 flavonoid glycosides, and 2 phenolic acids), with 17 shared between raw and vinegar-processed CRPV. Seven components reached hippocampal tissues(all common to both forms). In regulating emotional disorders, Vinegar-processed CRPV exhibited superior antidepressant-like effects compared to raw products. HE staining revealed that both treatments improved hippocampal neuronal morphology, particularly in the damaged CA1 and CA3 regions. Immunofluorescence and ELISA analyses demonstrated that both raw and vinegar-processed CRPV significantly modulated NeuN and PPARα expressions in hippocampal tissue while alleviating oxidative stress induced by excessive ROS(P<0.05). ConclusionThe chemical composition of CRPV undergoes changes after vinegar processing, but the migrating components in blood and hippocampus are primarily methoxyflavonoids. These components may serve as the potential material basis for activating the PPARα pathway, thereby negatively regulating ROS generation in the hippocampus, reducing oxidative stress, and promoting the development of NeuN-positive neurons. These findings provide experimental evidence for enhancing quality standards, pharmacodynamic material research, and active drug development of raw and vinegar-processed CRPV.
2.Expert consensus on the clinical application of parenteral direct thrombin inhibitors in special populations
Xin YAO ; Yuan BIAN ; Lizhu HAN ; Qinan YIN ; Yang LEI ; Zimeng WAN ; Luyao HUANG ; Danjie ZHAO ; Yu YAN ; Qin LI ; Baorong HU
China Pharmacy 2026;37(8):965-975
OBJECTIVE To form an expert consensus addressing clinical issues regarding the use of parenteral direct thrombin inhibitors (DTIs) in special populations. METHODS Led by the Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital(the Affiliated Hospital of UESTC), a multidisciplinary working group was formed comprising experts from multiple fields, including clinical pharmacy, cardiac surgery, obstetrics, pediatrics and evidence-based medicine. Through literature review and the Delphi method, clinical questions regarding the efficacy and safety of parenteral DTIs used in special populations were identified. A structured design was adopted using the “Population-Intervention-Comparison-Outcome” (PICO) framework;systematic searches were conducted in CJFD, PubMed, Embase and other databases. Relevant evidence from randomized controlled trials,cohort studies and systematic reviews were included and synthesized. Evidence quality was assessed using the Grading of Recommendations Assessment,Development and Evaluation (GRADE) approach, and recommendations were formulated through three rounds of Delphi surveys and expert consensus meetings. RESULTS &CONCLUSIONS Seven clinical questions were ultimately selected (with a consensus rate exceeding 90%), resulting in the formulation of seven recommendations on the use of parenteral DTIs in special populations, including children, pregnant women, patients with hepatic or renal impairment, patients with mesenteric venous thrombosis, and individuals with thrombophilia. These recommendations clarify the preferred agents, dosing ranges, monitoring parameters, and safety management strategies for parenteral DTIs in these special populations. This expert consensus, which is formulated based on the best available evidence, provides evidence-based guidance for standardized and individualized use of parenteral DTIs in special populations.
3.Transcriptomic responses of Bulinus globosus to extreme temperature and drought stress
Xinyao WANG ; Dandan PENG ; Ying YANG ; Jianfeng ZHANG ; Zhiqiang QIN ; Kun YANG ; Shizhu LI ; Jing XU
Chinese Journal of Schistosomiasis Control 2026;38(1):29-37
Objective To examine the impact of extreme temperature and drought stress on the survival of Bulinus globosus, so as to provide the theoretical evidence for the genomic research of Bulinus in absence of reference genes. Methods B. globosus snail samples were collected from Kiwani Shehia in Pemba Island, Zanzibar, Tanzania, and offspring snails were obtained through laboratory breeding and reproduction. A total of 120 10-week-old B. globosus snails from the same generation were selected and randomly assigned into four groups, including the high-temperature drought (HD) group, normal temperature drought (D) group, low-temperature drought (LD) group, and the control (C) group, of 30 snails in each group. Snails in HD, D, and LD groups were placed in beakers containing dry soil at the bottom and subsequently housed in climate chambers at 35, 26 ℃, and 10 ℃, respectively, while snails in Group C were maintained in 500 mL petri dishes containing dechlorinated tap water at 26 ℃. Following 3 days of breeding, living snails in each group were collected, and soft tissues were dissected and isolated. Total RNA was extracted from snail soft tissues for library construction, followed by high-throughput sequencing on the Illumina HiSeq 4000 sequencing system. De novo transcriptome assembly was performed using the Trinity software, and the longest transcripts were selected as unigenes. Gene functional annotations of unigenes were conducted using the Diamond software against Gene Ontology (GO) knowledgebase, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database, NCBI non-redundant (NR) protein sequences database, Protein Family (Pfam) database, and UniProtKB/Swiss-Prot (Swiss-Prot) knowledgebase. GO and KEGG enrichment analyses of differentially expressed genes (DEGs) were performed using the topGO and clusterProfiler software, respectively. In addition, four relevant genes were selected for validation using a real-time quantitative PCR (qRT-PCR) assay to verify the reliability of transcriptome sequencing results. Results Following 3 days of breeding, there were 7, 20, 28, and 30 survival B. globosus snails in HD, LD, D, and C groups, with corresponding survival rates of 23.33% (7/30), 66.67% (20/30), 93.33% (28/30), and 100.00% (30/30), respectively (χ2 = 52.72, P < 0.001). De novo transcriptome assembly generated 176 942 unigenes, with annotation rates of 0.98%, 13.49%, 26.46%, 12.48%, and 14.39% against GO knowledgebase, KEGG pathway database, NR protein sequences database, Pfam database, and Swiss-Prot knowledgebase, respectively. There were 33 up-regulated and 72 down-regulated genes in Group D, 483 up-regulated and 815 down-regulated genes in Group HD, and 245 up-regulated and 172 down-regulated genes in Group LD relative to in Group C. Following removal of overlapping genes across groups and unmatched genes, 11 candidate genes were identified. GO and KEGG analyses revealed 3 heat shock protein (HSP)-related DEGs in these 11 candidate genes, which were annotated as HSP12.2, HSP70, and HSP20 genes and were all significantly up-regulated in each treatment group. Three immune and nervous system-related DEGs were identified, and were all significantly down-regulated in each treatment group, which were involved in the neural cell adhesion molecule L1-like protein pathway, fibrinogen binding protein pathway, and leukocyte elastase inhibitor-like protein pathway. qRT-PCR assay quantified that the expression trends of four genes related to temperature and drought stress across different treatment groups were highly consistent with transcriptome sequencing data. Conclusion The survival rate of B. globosus significantly reduces under combined stresses of extreme temperature and drought, possibly due to an imbalance in its cellular homeostasis regulatory system.
4.Advances in detection techniques for congenital blood group chimerism
Shuo ZHANG ; Hongyan YANG ; Yuhan GAO ; Ranran QIN ; Xinrui WANG ; Ke ZHANG ; Yifan LI ; Ruiqin HOU
Chinese Journal of Blood Transfusion 2026;39(3):402-407
Congenital blood group chimerism refers to the coexistence of two or more distinct blood types within an individual, resulting from the presence of hematopoietic cell populations with different genotypes. Consequently, red blood cells in such individuals may express different blood group antigens. Based on the timing and mechanism of formation, blood group chimerism can be classified as either congenital or acquired. Although congenital blood group chimerism is rare and involves complex mechanisms, it holds significant implications in transfusion medicine, transplantation, and obstetrics. This article reviews the formation mechanisms, detection methods, and clinical significance of congenital blood group chimerism in transfusion medicine. Particular emphasis is placed on the principles, advantages, and limitations of various detection techniques. Furthermore, the potential applications of these technologies in clinical diagnosis are discussed, providing a technical foundation for the development of precise transfusion strategies.
5.Mechanisms of Bushen Tongluo Jiangzhuo Prescription in Improving Renal Fibrosis in Rats with Chronic Kidney Disease Based on PI3K/Akt/mTOR Signaling Pathway
Xincui BAO ; Baosheng ZHAO ; Lingling QIN ; Haiyan WANG ; Jing YANG ; You WANG ; Lijia WU ; Yujin LI ; Ming GAO ; Cuiyan LYU ; Tonghua LIU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(6):100-108
ObjectiveTo investigate the mechanisms by which Bushen Tongluo Jiangzhuo prescription improves renal fibrosis in rats with chronic kidney disease (CKD) through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. MethodsSeventy specific pathogen-free (SPF) Sprague-Dawley (SD) rats were randomly divided into a control group (n=15) and a modeling group (n=55). Rats in the modeling group were administered a 2.5% adenine suspension at a dose of 200 mg·kg-1·d-1 by gavage for 4 weeks to establish a CKD model. Successfully modeled rats were randomly divided into a model group, an irbesartan group (20.25 mg·kg-1·d-1), and Bushen Tongluo Jiangzhuo prescription low-, medium-, and high-dose groups (5.82, 11.64, and 23.28 g·kg-1·d-1, respectively), with 10 rats in each group. Each group was administered an equal volume of physiological saline, the corresponding concentration of irbesartan, or Bushen Tongluo Jiangzhuo prescription by gavage for 12 weeks. Body weight and renal function indices were dynamically monitored. Serum creatinine (SCr), blood urea nitrogen (BUN), urine albumin-to-creatinine ratio (ACR), 24-hour urinary total protein (24 hUTP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels were measured using an automatic biochemical analyzer. Renal histopathological changes were observed by hematoxylin-eosin (HE) and Masson staining. Immunohistochemistry (IHC) was used to detect the expression of PI3K, Akt, phosphorylated Akt (p-Akt), and mTOR in renal tissues. Western blot was performed to assess the protein expression of PI3K, p-Akt, Akt, phosphorylated mTOR (p-mTOR), and mTOR in renal tissues. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to determine the mRNA expression levels of PI3K, Akt, and mTOR in renal tissues. ResultsCompared with the model group, rats in the irbesartan group and the low-, medium-, and high-dose Bushen Tongluo Jiangzhuo prescription groups showed significantly decreased levels of SCr, BUN, ACR, 24 hUTP, IL-1β, IL-6, and TNF-α (P<0.01). AST levels were significantly increased (P<0.01), while no significant difference was observed in ALT levels. Histopathological examination revealed that, compared with the model group, renal tubular epithelial cell edema and necrosis and Bowman's capsule dilation were alleviated, inflammatory cell infiltration was reduced, and interstitial and glomerular fibrosis was markedly improved in all treatment groups, with the most pronounced effect observed in the high-dose Bushen Tongluo Jiangzhuo prescription group. Real-time PCR results showed that mRNA expression levels of PI3K, Akt, and mTOR were significantly downregulated in the high-dose group (P<0.01). IHC results demonstrated that PI3K and p-Akt expression levels in renal tissues were significantly decreased in the high-dose group (P<0.01). Western blot analysis further confirmed that the expression levels of PI3K, p-Akt/Akt, and p-mTOR/mTOR were significantly reduced in the high-dose group (P<0.01). ConclusionBushen Tongluo Jiangzhuo prescription improves renal function indices in CKD rats, reduces collagen deposition in renal tissues, and decreases serum inflammatory factor levels. Its protective effect on renal function may be achieved by activating autophagy through downregulation of the PI3K/Akt/mTOR signaling pathway, thereby alleviating renal fibrosis.
6.Qualitative and Quantitative Analysis of Chemical Constituents in Gualou Niubangtang by UPLC-Q-TOF-MS/MS and HPLC
Yiyi ZHANG ; Jing YANG ; Yuqing CHENG ; Huimin GAO ; Jin QIN ; Li YAO ; Xiyang DU ; Raorao LI
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(6):179-187
ObjectiveThis paper aims to clarify the material basis of Gualou Niubangtang and establish a quantitative analysis method for its main constituents, providing a reference for the overall quality control of this preparation. MethodsThe constituents in the formula were systematically characterized based on ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Identification was performed by matching with the UNIFI 9.6 software and utilizing database platforms such as PubChem, ChemicalBook, and ChemSpider, combined with relevant literature reports. A quantitative analysis method for the seven main constituents in Gualou Niubangtang was established by using high performance liquid chromatography (HPLC). ResultsUPLC-Q-TOF-MS/MS analysis identified 155 constituents, including 69 flavonoids, 36 terpenoids, 23 phenylpropanoids, 8 phenylethanoid glycosides, and 19 other types of constituents. In the established quantitative analysis method, the seven main constituents showed good linearity within their respective linear ranges. The precision, repeatability, stability, and spike recovery all met the required standards. The results showed that the content ranges of geniposide, liquiritin, hesperidin, arctiin, baicalin, oroxylin A-7-O-β-D-glucuronide, and wogonoside in 15 batches of Gualou Niubangtang were 13.67-21.25, 1.20-7.64, 5.45-7.45, 22.97-33.51, 29.95-39.07, 2.58-4.80, and 6.56-9.31 mg·g-1, respectively. ConclusionThis study successfully characterizes and attributes multi-category constituents in Gualou Niubangtang, clarifying that its material basis is primarily composed of flavonoids, terpenoids, phenylethanoid glycosides, and phenylpropanoids. Furthermore, it enables the quantification of seven constituents within the formula. This work lays a foundation for research on the quality control, action mechanism, and clinical application of this formula.
7.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
8.A Computational Perspective on Differences Between MHC-I and MHC-II in TCR-pMHC Structure Prediction Resources: Review and Benchmarking
Xiao-Qin WU ; Da-Wei LIU ; Bin-Yu LI ; Yang LIU ; Yang CAO ; Wen-Tao DAI
Progress in Biochemistry and Biophysics 2026;53(5):1376-1399
The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.
9.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
10.A Computational Perspective on Differences Between MHC-I and MHC-II in TCR-pMHC Structure Prediction Resources: Review and Benchmarking
Xiao-Qin WU ; Da-Wei LIU ; Bin-Yu LI ; Yang LIU ; Yang CAO ; Wen-Tao DAI
Progress in Biochemistry and Biophysics 2026;53(5):1376-1399
The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.

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