1.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.
2.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.
3.Expression and Clinical Significance of PLCβ4 Gene in Hepatocellular Carcinoma Analyzed Based on TCGA Database and Experimental Validation
Limei WEN ; Yali GUO ; Qiang HOU ; Dongxuan ZHENG ; Wu DAI ; Xiang GAO ; Jianhua YANG ; Junping HU
Cancer Research on Prevention and Treatment 2025;52(6):502-510
Objective To analyze the PLCβ4 gene mRNA expression and its clinical significance in hepatocellular carcinoma (HCC) based on TCGA database. Methods Based on the data on 424 clinical samples (including 374 cases of HCC tissues and 50 cases of nontumor liver tissues) in the TCGA database, Kaplan–Meier method, Cox regression analysis, and immune infiltration analysis were performed to evaluate the relationship between PLCβ4 gene and the clinical characteristics and survival prognosis of HCC patients. Correlation analysis between PLCβ4 gene and 24 types of immune cells was applied to investigate the relationship between PLCβ4 gene and immune cell infiltration and mRNA expression level of TP53 gene, a high-frequency mutation gene in HCC. In addition, paraffin sections of highly, moderately, and poorly differentiated tumor tissues and normal liver tissues from HCC patients were collected. The histopathological observation was carried out via HE staining method, and the expression levels of PLCβ4 and Ki-67 proteins in each clinical sample were verified through the immunohistochemical method. Results The expression level of PLCβ4 gene in HCC was significantly higher than that in normal tissues (P<0.01), and all patients in the PLCβ4 high-expression group had a significantly longer overall survival than those in the low-expression group (P<0.05), which suggested that PLCβ4 substantially affected the prognosis of HCC patients. Correlation analysis showed that the expression level of PLCβ4 gene was highly correlated with immune cell infiltration and the expression level of TP53 gene. As verified by clinical sample experiments, HE staining experiments and immunohistochemical results revealed that PLCβ4 gene expression in HCC tissue samples was significantly higher than that in normal tissues (P<0.001), and it was negatively correlated with the degree of differentiation. Conclusion PLCβ4 may serve as an independent prognostic factor in HCC and is expected to be a novel molecular target for HCC treatment.
4.Analysis of PIKFYVE gene expression, clinical significance, and experimental validation based on TCGA database in hepatocellular carcinoma
Limei WEN ; Yali GUO ; Dongxuan ZHENG ; Qiang HOU ; Wu DAI ; Xiang GAO ; Jianhua YANG
Chinese Journal of Hepatology 2025;33(2):159-169
Objective:To experimentally validate clinical samples, analyze the mRNA expression of the FYVE domain containing phosphatidylinositol 3-phosphate 5 kinase ( PIKFYVE) gene, and its clinical significance based on the Cancer Genome Atlas (TCGA) database in hepatocellular carcinoma (HCC). Methods:Data information on 424 clinical samples (including 374 cases of HCC tissues and 50 cases of non-tumorous liver tissues) were collected based on the TCGA database. Cox regression analysis and the Kaplan-Meier method were used to analyze the relationship between mRNA expression of the PIKFYVE gene and the clinical characteristics as well as survival prognosis in patients with HCC. The relationship between the PIKFYVE gene and immune cell infiltration was examined by correlation analysis with 24 kinds of immune cells. In addition, the mRNA expression level of the PIKFYVE gene and RAC-alpha serine/threonine-protein kinase ( AKT1), phosphatase and tensin homolog ( PTEN), protein kinase C alpha ( PRKCA), inositol polyphosphate-5-phosphatase ( INPP5D), phosphoinositide-3-kinase regulatory subunit 1 ( PIK3R1), inositol polyphosphate 4-phosphatase type II ( INPP4B) and phospholipase C beta 4 ( PLCB4) gene correlations were analyzed in HCC tissues. At the same time, paraffin sections of highly differentiated, moderately differentiated, poorly differentiated, and non-tumor liver tissues from patients with HCC were collected from the Department of Pathology of the First Affiliated Hospital of Xinjiang Medical University. The histopathological observation was performed by HE staining. Immunohistochemistry was used to verify the expression levels of the PIKFYVE and Ki67 proteins in each clinical sample. The t-test was used for intergroup comparison of continuous data. The χ2 test and Wilcoxon rank sum test were used for intergroup comparison of enumeration data. The Kaplan-Meier method was used for survival analysis. Results:The expression level of the PIKFYVE gene was higher in the HCC tumor than that in normal liver tissue ( P<0.01). The overall survival time of patients was significantly longer in the low expression group than that in the high expression group ( HR=1.57, 95% CI: 1.10~2.25, P=0.014). The results of univariate Cox regression analysis showed that tumor stage, pathological grade, tumor status, residual tumor, and PIKFYVE expression level all had an effect on OS ( P<0.05). The PIKFYVE prognostic risk model had a proportionate score of HR=1.533 (95% CI: 1.077~2.181, P=0.018). Multivariate Cox risk regression analysis showed that the PIKFYVE prognostic risk model had a proportionate score of HR=1.481 (95% CI: 0.886~2.476, P=0.134) and an area under the receiver operating characteristic curve of 0.559, indicating that it had predictive value for survival prediction. The results of the correlation analysis showed that the expression level of PIKFYVE was strongly correlated with immune cell infiltration and TP53 ( P<0.01). The results of immunohistochemical staining showed that the expression level of PIKFYVE was significantly higher in HCC tissue samples than that in non-tumor liver tissues ( P<0.01), and was negatively correlated with the degree of differentiation. Conclusion:PIKFYVE, as an independent risk factor, is expected to be developed into a biomarker for clinical diagnosis, offering a reference for novel therapeutic agents in HCC.
6.Validation of retinoblastoma mouse model based on fluorescence imaging technology
Cailing DAI ; Wei YANG ; Limei WANG ; Jinlong DAI ; Yuying WEN ; Jianmin GUO
International Eye Science 2025;25(5):706-713
AIM: To provide references for the non-clinical evaluation of therapeutic targets or drugs for retinoblastoma, fluorescently labeled Y79 cells are injected into the vitreous body of BALB/c-nu mice to establish a retinoblastoma model, and the Melphalan treatment group is used as a positive control, which is verified by fluorescence imaging technology.METHODS: BALB/c-nu mice were intravitreous injected with GFP transfected Y79 cells(1.0×107 cell/mL, 3 μL)to establish the model. On the 27th day, the mice were randomly divided into model control group and different doses of Melphalan groups(1, 3, 10 μg/eye groups)according to the fluorescence value of in vivo imaging, with vitreous body single administrated and ocular symptoms observed daily. Slit-lamp examination was performed at 12, 20, 29, 35, 42, 48, 55, 76, and 83 d after modeling. In vivo imaging was performed on 12, 20, 27, 41, 48, 55, 62, 69, 76, and 83 d. At the last treatment, the eyeball, brain and cerebellum tissues were removed for histopathological examination.RESULTS: From the sixth day of modeling, cloud-like substances could be seen in the eyes of the animals, and the cloud-like substances occupied the whole eyeball of the mice in the model control group at the later stage, accompanied by irregular growth of blood vessels. After 27 days of modeling, the fluorescence value was detected in all the animals, and the fluorescence value continued to increase with the extension of modeling time. The fluorescence value of the tumor reached the peak after 69-83 days of modeling. Histological examination showed severe proliferation of intraocular tumor cells in the model control group, and tumor cells were observed in the brain of 1 model animal. In the 10 μg/eye Melphalan group, the fluorescence value was significantly decreased at 17 d after administration. The fluorescence value of the 3 μg/eye Melphalan group was significantly inhibited at 59 d after administration. No tumor cells were found in the brain tissue of animals in all Melphalan groups.CONCLUSION: After vitreous injection of Y79/pCDH-LUC-copGFP cells in BALB/c-nu mice, significant ocular lesions and proliferation of tumor cells were observed in the eyes. Meanwhile, Melphalan intervention significantly inhibited tumor cells in a dose-dependent manner, indicating that the mouse model of retinoblastoma was successfully constructed.
7.Mechanisms of Zhuyuwan in Treating both Intrahepatic Cholestasis and Ulcerative Colitis Based on Homotherapy for Heteropathy
Jun HAN ; Yueqiang WEN ; Zongying XU ; Dan LUO ; Li ZHOU ; Xueyi LI ; Yufan DAI ; Lele YANG ; Tao SHEN ; Han YU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):46-53
ObjectiveThe theory of homotherapy for heteropathy is one of the classical rules in traditional Chinese medicine. Taking this theory as a breakthrough point, this study employed gas chromatography-mass spectrometry (GC-MS) to elucidate the mechanism underlying the therapeutic effects of Zhuyuwan on both intrahepatic cholestasis (IC) and ulcerative colitis (UC) from the viewpoint of serum metabolic homeostasis. MethodsThe rat models of α-naphthylisothiocyanate (ANIT)-induced cholestasis and 2,4,6-trinitro-benzenesulfonic acid (TNBS)-induced UC were treated with low (0.6 g·kg-1) and high (1.2 g·kg-1) doses of Zhuyuwan by gavage. In the experiment regarding IC, 24 Sprague-Dawley (SD) rats were randomly assigned into four groups: normal, ANIT model, low-dose Zhuyuwan, and high-dose Zhuyuwan. In the experiment regarding UC, 24 SD rats were randomly allocated into four groups: normal, TNBS model, low-dose Zhuyuwan, and high-dose Zhuyuwan. Firstly, the two disease models and the intervention effects of Zhuyuwan on the two diseases were evaluated based on serum levels of biochemical indicators [alanine aminotransferase (ALT), aspartate transaminase (AST), γ-glutamyltranspeptidase (γ-GT), and total bile acid (TBA)], colon damage score, colon weight index, disease activity index, and histopathological changes in rats. Secondly, the rat serum samples were analyzed by gas chromatography-mass spectrometry (GC-MS) to screen the common core pathways of the two disease models, and the expression of core genes in the pathways was determined by Real-time PCR, on the basis of which the biological mechanism of the treatment of the two disease models by Zhuyuwan was ultimately elucidated. ResultsThe results of the experiment regarding IC showed that the ANIT model group had higher ALT, AST, γ-GT, and TBA levels than the normal group (P<0.01). Compared with the ANIT model group, the low-dose Zhuyuwan group showed declined ALT and TBA levels (P<0.01) and the high-dose Zhuyuwan group showed lowered ALT, TBA, AST, and γ-GT levels (P<0.01). The results of the experiment regarding UC showed that compared with the normal group, the TNBS model group presented increases in the colonic damage score, colon weight index, and disease activity index (P<0.01). Compared with the TNBS model group, the low-dose Zhuyuwan group showcased declines in colon weight index (P<0.01) and disease activity index (P<0.05), and the high-dose Zhuyuwan group showed reductions in the colon damage score, colon weight index, and disease activity index (P<0.01). GC-MS metabolomics analysis combined with qRT-PCR demonstrated that Zhuyuwan had a similar inverse regulatory effect on arginine metabolism disruption in the above two disease models. ConclusionZhuyuwan exhibited definite therapeutic effects on both IC and UC, and the regulation of arginine biosynthesis pathway is the core mechanism for the treatment of both diseases by Zhuyuwan.
8.Mechanisms of Zhuyuwan in Treating both Intrahepatic Cholestasis and Ulcerative Colitis Based on Homotherapy for Heteropathy
Jun HAN ; Yueqiang WEN ; Zongying XU ; Dan LUO ; Li ZHOU ; Xueyi LI ; Yufan DAI ; Lele YANG ; Tao SHEN ; Han YU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(13):46-53
ObjectiveThe theory of homotherapy for heteropathy is one of the classical rules in traditional Chinese medicine. Taking this theory as a breakthrough point, this study employed gas chromatography-mass spectrometry (GC-MS) to elucidate the mechanism underlying the therapeutic effects of Zhuyuwan on both intrahepatic cholestasis (IC) and ulcerative colitis (UC) from the viewpoint of serum metabolic homeostasis. MethodsThe rat models of α-naphthylisothiocyanate (ANIT)-induced cholestasis and 2,4,6-trinitro-benzenesulfonic acid (TNBS)-induced UC were treated with low (0.6 g·kg-1) and high (1.2 g·kg-1) doses of Zhuyuwan by gavage. In the experiment regarding IC, 24 Sprague-Dawley (SD) rats were randomly assigned into four groups: normal, ANIT model, low-dose Zhuyuwan, and high-dose Zhuyuwan. In the experiment regarding UC, 24 SD rats were randomly allocated into four groups: normal, TNBS model, low-dose Zhuyuwan, and high-dose Zhuyuwan. Firstly, the two disease models and the intervention effects of Zhuyuwan on the two diseases were evaluated based on serum levels of biochemical indicators [alanine aminotransferase (ALT), aspartate transaminase (AST), γ-glutamyltranspeptidase (γ-GT), and total bile acid (TBA)], colon damage score, colon weight index, disease activity index, and histopathological changes in rats. Secondly, the rat serum samples were analyzed by gas chromatography-mass spectrometry (GC-MS) to screen the common core pathways of the two disease models, and the expression of core genes in the pathways was determined by Real-time PCR, on the basis of which the biological mechanism of the treatment of the two disease models by Zhuyuwan was ultimately elucidated. ResultsThe results of the experiment regarding IC showed that the ANIT model group had higher ALT, AST, γ-GT, and TBA levels than the normal group (P<0.01). Compared with the ANIT model group, the low-dose Zhuyuwan group showed declined ALT and TBA levels (P<0.01) and the high-dose Zhuyuwan group showed lowered ALT, TBA, AST, and γ-GT levels (P<0.01). The results of the experiment regarding UC showed that compared with the normal group, the TNBS model group presented increases in the colonic damage score, colon weight index, and disease activity index (P<0.01). Compared with the TNBS model group, the low-dose Zhuyuwan group showcased declines in colon weight index (P<0.01) and disease activity index (P<0.05), and the high-dose Zhuyuwan group showed reductions in the colon damage score, colon weight index, and disease activity index (P<0.01). GC-MS metabolomics analysis combined with qRT-PCR demonstrated that Zhuyuwan had a similar inverse regulatory effect on arginine metabolism disruption in the above two disease models. ConclusionZhuyuwan exhibited definite therapeutic effects on both IC and UC, and the regulation of arginine biosynthesis pathway is the core mechanism for the treatment of both diseases by Zhuyuwan.
9.Eccentric treadmill exercise promotes adaptive hypertrophy of gastrocnemius in rats.
Zhi-Qiang DAI ; Yu KE ; Yan ZHAO ; Ying YANG ; Hui-Wen WU ; Hua-Yu SHANG ; Zhi XIA
Acta Physiologica Sinica 2025;77(3):449-464
The present study aimed to investigate the effects of eccentric treadmill exercise on adaptive hypertrophy of skeletal muscle in rats. Thirty-two 3-month-old Sprague Dawley (SD) rats were selected and randomly assigned to one of the four groups based on their body weights: 2-week quiet control group (2C), 2-week downhill running exercise group (2E), 4-week quiet control group (4C), and 4-week downhill running exercise group (4E). The downhill running protocol for rats in the exercise groups involved slope of -16°, running speed of 16 m/min, training duration of 90 min, and 5 training sessions per week. Twenty-four hours after the final session of training, all the four groups of rats underwent an exhaustion treadmill exercise. After resting for 48 h, all the rats were euthanized and their gastrocnemius muscles were harvested for analysis. HE staining was used to measure the cross-sectional area (CSA) and diameter of muscle fibers. Transmission electron microscope was used to observe the ultrastructural changes in muscle fibers. Purithromycin surface labeling translation method was used to measure protein synthesis rate. Immunofluorescence double labeling was used to detect the colocalization levels of lysosomal-associated membrane protein 2 (Lamp2)-leucyl-tRNA synthetase (LARS) and Lamp2-mammalian target of rapamycin (mTOR). Western blot was used to measure the protein expression levels of myosin heavy chain (MHC) IIb and LARS, as well as the phosphorylation levels of mTOR, p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The results showed that, compared with the 2C group rats, the 2E group rats showed significant increases in wet weight of gastrocnemius muscle, wet weight/body weight ratio, running distance, running time, pre- and post-exercise blood lactate levels, myofibrillar protein content, colocalization levels of Lamp2-LARS and Lamp2-mTOR, and LARS protein expression. Besides these above changes, compared with the 4C group, the 4E group further exhibited significantly increased fiber CSA, fiber diameter, protein synthesis rate, and phosphorylation levels of mTOR, p70S6K, and 4E-BP1. Compared with the quiet control groups, the exercise groups exhibited ultrastructural damage of rat gastrocnemius muscle, which was more pronounced in the 4E group. These findings suggest that eccentric treadmill exercise may promote mTOR translocation to lysosomal membrane, activating mTOR signaling via up-regulating LARS expression. This, in turn, increases protein synthesis rate through the mTOR-p70S6K-4E-BP1 signaling pathway, promoting protein deposition and inducing adaptive skeletal muscle hypertrophy. Although the ultrastructural changes of skeletal muscle are more pronounced, the relatively long training cycles during short-term exercise periods have a more significant effect on promoting gastrocnemius muscle protein synthesis and adaptive hypertrophy.
Animals
;
Rats, Sprague-Dawley
;
Physical Conditioning, Animal/physiology*
;
Rats
;
Muscle, Skeletal/metabolism*
;
TOR Serine-Threonine Kinases/metabolism*
;
Male
;
Hypertrophy
;
Adaptation, Physiological/physiology*
;
Adaptor Proteins, Signal Transducing/metabolism*
;
Ribosomal Protein S6 Kinases, 70-kDa/metabolism*
;
Intracellular Signaling Peptides and Proteins
10.Carbon-friendly ecological cultivation mode of Dendrobium huoshanense based on greenhouse gas emission measurement.
Di TIAN ; Jun-Wei YANG ; Bing-Rui CHEN ; Xiu-Lian CHI ; Yan-Yan HU ; Sheng-Nan TANG ; Guang YANG ; Meng CHENG ; Ya-Feng DAI ; Shi-Wen WANG
China Journal of Chinese Materia Medica 2025;50(1):93-101
Ecological cultivation is an important way for the sustainable production of traditional Chinese medicine in the context of the carbon peaking and carbon neutrality goals. Facility cultivation and simulative habitat cultivation modes have been developed and applied to develop the endangered Dendrobium huoshanense on the basis of protection. However, the differences in the greenhouse gas emissions and global warming potential of these cultivation modes remain unexplored, which limits the accurate assessment of carbon-friendly ecological cultivation modes of D. huoshanense. Greenhouse gas emission flux monitoring based on the static chamber method provides an effective way to solve this problem. Therefore, this study conducted a field experiment in the facility cultivation and simulative habitat cultivation modes at a D. huoshanense cultivation base in Dabie Mountains, Anhui Province. From April 2023 to March 2024, samples of greenhouse gases were collected every month, and the concentrations of CO_2, CH_4, and N_2O of the samples were then detected by gas chromatography. The greenhouse gas emission fluxes, cumulative emissions, and global warming potential were further calculated, and the following results were obtained.(1)The two cultivation modes of D. huoshanense showed significant differences in greenhouse gas emission fluxes, especially the CO_2 emission flux, with a pattern of facility cultivation>simulative habitat cultivation [(35.60±11.70)mg·m~(-2)·h~(-1) vs(2.10±4.59)mg·m~(-2)·h~(-1)].(2) The annual cumulative CO_2 emission flux in the case of facility cultivation was significantly higher than that of simulative habitat cultivation[(3 077.00±842.00)kg·hm~(-2) vs(221.00±332.00)kg·hm~(-2)], while no significant difference was found in annual cumulative CH_4 and N_2O emission fluxes.(3) The facility cultivation mode had a significantly higher global warming potential than the simulative habitat cultivation mode [(3 053.00±847.00)kg·hm~(-2) vs(196.00±362.00)kg·hm~(-2)]. Overall, the simulative habitat cultivation of D. huoshanense has obvious carbon-friendly characteristics compared with facility cultivation, which is in line with the concept of ecological cultivation of medicinal plants. This study is of great reference significance for the implementation and promotion of the ecological cultivation mode of D. huoshanense under carbon peaking and carbon neutrality goals.
Dendrobium/chemistry*
;
Greenhouse Gases/metabolism*
;
Carbon/analysis*
;
Ecosystem
;
Carbon Dioxide/metabolism*
;
China
;
Global Warming

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