1.Olfactory Receptors Expressed in The Intestine and Their Functions
Pei-Wen YANG ; Meng-Meng YUAN ; Ying ZHOU ; Peng LI ; Gui-Hong QI ; Ying YANG ; Zhong-Yi MAO ; Meng-Sha ZHOU ; Xiao-Shuang MAO ; Jian-Ping XIE ; Yi-Nan YANG ; Shi-Hao SUN
Progress in Biochemistry and Biophysics 2026;53(3):534-549
Olfactory receptors (ORs) form the largest superfamily of G protein-coupled receptors (GPCRs). Traditionally recognized for their role in the nasal olfactory epithelium, where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidneys. The intestine, as the primary site for nutrient digestion and absorption, harbors a highly complex chemical environment. To adapt to this environment, the gut employs a sophisticated network of “chemosensors” to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as crucial functional components, serving as a molecular bridge that connects environmental chemical signals—such as food-derived odorants—to specific physiological responses. This discovery has significantly deepened our understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Studies indicate that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a wide variety of ligands, including exogenous dietary components, gut microbiota metabolites such as short-chain fatty acids, and endogenous small molecules like azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to elucidate the molecular mechanisms by which these receptors regulate the secretion of gut hormones. Activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility. Furthermore, the review addresses the critical roles of ORs in immune regulation and pathology. Evidence suggests that specific ORs contribute to the maintenance of intestinal immune homeostasis and may offer protection against inflammation. Beyond their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation by remodeling the gut microbiome and metabolome. These findings collectively suggest that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and maintaining gut homeostasis. Additionally, the review explores the emerging role of ORs in cancer. Although OR expression is often downregulated in tumor tissues compared to normal mucosa, activation of specific ORs by certain ligands can inhibit tumor cell proliferation and migration and induce apoptosis via pathways such as MEK/ERK and p38 MAPK. Conversely, other receptors, such as OR7C1, may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut’s sensory network. The review also discusses the translational potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may thus emerge as promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases, and malignancies.
2.Synthesis of A New Naphthalenesulfonamide-based"Turn-on"Fluorescent Probe for Rapid Detection of Glyphosate
Rong-Rong ZHAO ; Hong-Lin LIU ; Ying-Ping HUANG ; Cui-Wen DENG ; Song-Yan LI ; Shui-Lian YU ; Mao-Sheng TAO ; Yi-Qun TIAN ; Xi YUAN
Chinese Journal of Analytical Chemistry 2025;53(6):903-913
Widespread utilization of glyphosate has led to environmental residues,posing potential threats to ecological systems and human health.Traditional methods for detection of glyphosate are limited by specialized equipment and operational techniques,resulting in inefficient responses.Therefore,it is urgent to develop a convenient,sensitive and accurate detection method for detection of glyphosate.Herein,a new naphthalenesulfonamide-based"Turn-on"fluorescent probe was synthesized using 2-chloroaniline and dansyl chloride as raw materials through a one-step process,which showed a good linear relationship between the glyphosate concentration in concentration range of 0.003-70 μmol/L and the fluorescence intensity(R2=0.995),with a detection limit of 2.73 nmol/L(S/N=3).Analytical techniques such as nuclear magnetic resonance(NMR)spectroscopy and high-resolution mass spectrometry(HRMS)were used to investigate the interaction mechanism between the fluorescent probe and glyphosate.The results indicated that a nucleophilic substitution reaction occurred between the probe and the secondary amine(—NH—)of glyphosate,inducing a photoinduced electron transfer(PET)effect which enhanced the fluorescence intensity by 11.2 times.The probe showed good anti-interference ability towards coexisting metal ions,anions and pesticides in water.When applied to determination of glyphosate in the samples such as tap water,river water(Xiangxi River Reservoir),soil,soybeans,and corn,the spiking recoveries ranged from 94.7%to 109.9%,demonstrating the high accuracy and broad applicability of this detection method.A portable test strip based on this fluorescent probe was developed for rapid semi-quantitative analysis of glyphosate.The developed method was rapid,sensitive,and portable,providing theoretical and technical support for on-site measurement of environmental contaminants.
3.Relationship between Serum IGFBP-3,IGF-1 and Cardiac Function and Short-Term Prognosis in Patients with Dilated Cardiomyopathy Complicated with Heart Failure
Li-juan YUAN ; Shi-yuan XIE ; Yan ZHOU ; Fa-mao LI ; Yi-wu ZHENG
Progress in Modern Biomedicine 2025;25(9):1576-1583
Objective:To observe the relationship between serum insulin-like growth factor binding protein-3(IGFBP-3),insulin-like growth factor-1(IGF-1)and cardiac function and short-term prognosis in patients with dilated cardiomyopathy(DCM)complicated with heart failure(HF).Methods:102 patients with DCM complicated with HF were selected as study group and they were divided into good prognosis group and poor prognosis group based on prognosis,and 100 patients with simple DCM during the same period were selected as the control group.The cardiac function indicators[left ventricular end systolic volume(LVESV),left ventricular ejection fraction(LVEF),left ventricular end diastolic volume(LVEDV)]and serum IGFBP-3 and IGF-1 levels between the control group and the study group were compared.The correlation between cardiac function and IGFBP-3,IGF-1 was analyzed by pearson analysis.The serum IGFBP-3 and IGF-1 leveles between good prognosis group and poor prognosis group were compared,the correlation between prognosis and IGFBP-3,IGF-1 was analyzed by spearman.Receiver operating characteristic(ROC)curves were used to analyze the predictive value of serum levels of IGFBP-3 and IGF-1 alone and in combination for the short-term prognosis of DCM complicated with HF patients.Results:Compared with control group,study group had higher LVEDV,LVESV,IGFBP-3,IGF-1,and lower LVEF(P<0.05).Pearson analysis results showed that,IGFBP-3 and IGF-1 were positively correlated with LVEDV and LVESV,while which was negatively correlated with LVEF(P<0.05).Compared with good prognosis group,poor prognosis group had higher IGFBP-3,IGF-1(P<0.05).Spearman correlation analysis results showed that,the levels of IGFBP-3 and IGF-1 were positively correlated with the poor prognosis of DCM complicated with HF patients(P<0.05).The area under the curve(AUC)of serum IGFBP-3,IGF-1 levels,and their combined use for short-term prognosis of DCM complicated with HF patients were 0.715,0.749,and 0.831,respectively.Conclusion:Serum IGFBP-3 and IGF-1 levels are elevated in patients with DCM complicated with HF,and the changes in these two indicators are associated with poor cardiac function and prognosis in patients.The combined detection of IGFBP-3 and IGF-1 levels has a high predictive value for the short-term prognosis of DCM combined with HF.
4.RICH1 regulates myocardial fibrosis through TGF-β/SMAD signaling pathway
Lu-xuan WAN ; Ying-qing HU ; Yuan-yuan LIU ; Yong-song TANG ; Jun-yi HUANG ; Zi-xuan ZHANG ; Xiao-xiao MAO ; Xin-wen NIE ; Zhan-hong REN
Chinese Pharmacological Bulletin 2025;41(11):2089-2096
Aim To reveal the mechanism of CIP4 homologs protein 1(RICH1)are involved in the regu-lation of myocardial fibrosis.Methods Mouse cardiac fibroblasts(MCFs)cells were treated with transforming growth factor-β(TGF-β1)to induce the formation of a myocardial fibrosis cell model;the level of the target protein was detected by Western blotting;and the RICH1 gene was detected by transfection of the cells with plasmid.The RICH1 gene was overexpressed(RICH 1 OE)using plasmid transfection;the RICH1 gene was silenced using siRNA fragment(siRICH1);and the expression levels of myocardial fibrosis marker genes,such as Col1 a1,Col3 a1,and Acta2,were de-tected using RT-qPCR.Results RICH1 was signifi-cantly down-regulated in TGF-β1-treated MCFs;the expression levels of myocardial fibrosis marker genes,such as Col1 a1,Col3a1,and Acta2,were down-regu-lated in the RICH1 OE+TGF-β1 group;and in the siRICH1+TGF-β1 group,myocardial fibrosis marker genes,such as Col1 a1,Col3a1 and Acta2 were up-regulated at the expression level;phosphorylated SMAD2(p-SMAD2)and phosphorylated SMAD3(p-SMAD3)levels were down-regulated in the siRICH1 OE+TGF-β1 group.p-SMAD2 and P-SMAD3 levels were upregulated in the siRICH1+TGF-β1 group.Conclusion RICH1 inhibits TGF-β1-induced myo-cardial fibrosis;RICH1 inhibits TGF-β1-induced myo-cardial fibrosis by negatively regulating the SMAD2/3 signaling pathway.
5.The Effects of the Combination of Curcumin,Berberine,and Puerarin on Lipid Levels in Hyperlipidemic Mice
Zhi-yuan FAN ; Yi-zhou XU ; Si-wei XU ; Xiong-hua XING ; Mao-lin LIU ; Xia YI
Progress in Modern Biomedicine 2025;25(13):2100-2109,2099
Objective:To investigate the effects of curcumin,berberine,and puerarin combination therapy on lipid levels in hyperlipidemic mice.Methods:A total of 40 male C57BL/6J mice were randomly divided into eight groups:normal control group(A),high-fat control group(B),curcumin group(C),berberine group(D),puerarin group(E),low-dose combination group of curcumin,berberine,and puerarin(F),high-dose combination group of curcumin,berberine,and puerarin(G),and positive control group(H),with 5 mice in each group.The normal control group was fed a standard diet,while the other groups were given a high-fat diet.After establishing the hyperlipidemic model,the mice were administered with physiological saline,curcumin(200 mg/kg),berberine(200 mg/kg),puerarin(300 mg/kg),low-dose combination of curcumin(50 mg/kg),berberine(50 mg/kg),and puerarin(100 mg/kg),high-dose combination of curcumin(200 mg/kg),berberine(200 mg/kg),and puerarin(300 mg/kg),or simvastatin(6 mg/kg)via gavage for three weeks.After treatment,serum was collected from the mice for biochemical analysis of lipid levels and liver function.Liver tissues were subjected to HE staining,Western blot analysis and real-time quantitative PCR.Results:Curcumin,berberine,and puerarin,whether administered individually or in combination,can reduce the body weight of hyperlipidemic mice(P<0.01).Treatment with curcumin,berberine,and puerarin individually significantly reduced lipid levels in hyperlipidemic mice(P<0.05)and alleviated liver damage caused by hyperlipidemia(P<0.05).Furthermore,the high-dose combination of curcumin,berberine,and puerarin exhibited a more pronounced effect on improving lipid levels(P<0.01)and provided greater protective effects on the liver compared to the positive control group(P<0.05).Additionally,curcumin,berberine,and puerarin administered individually can each promote the expression of the LDLR gene in high-fat diet mice(increased by 90%,85%,and 98%,respectively)and reduce the expression of the ACC gene(decreased by 42%,45%,and 43%,respectively).The combination of all three compounds enhances the expression of the LDLR gene in high-fat diet mice(increased by 90%with low-dose combination and 169%with high-dose combination)and reduces the expression of the ACC gene(decreased by 38%with low-dose combination and 42%with high-dose combination).Conclusion:The combination of curcumin,berberine,and puerarin significantly improves lipid levels in hyperlipidemic mice and mitigates liver damage associated with hyperlipidemia.
6.RICH1 regulates myocardial fibrosis through TGF-β/SMAD signaling pathway
Lu-xuan WAN ; Ying-qing HU ; Yuan-yuan LIU ; Yong-song TANG ; Jun-yi HUANG ; Zi-xuan ZHANG ; Xiao-xiao MAO ; Xin-wen NIE ; Zhan-hong REN
Chinese Pharmacological Bulletin 2025;41(11):2089-2096
Aim To reveal the mechanism of CIP4 homologs protein 1(RICH1)are involved in the regu-lation of myocardial fibrosis.Methods Mouse cardiac fibroblasts(MCFs)cells were treated with transforming growth factor-β(TGF-β1)to induce the formation of a myocardial fibrosis cell model;the level of the target protein was detected by Western blotting;and the RICH1 gene was detected by transfection of the cells with plasmid.The RICH1 gene was overexpressed(RICH 1 OE)using plasmid transfection;the RICH1 gene was silenced using siRNA fragment(siRICH1);and the expression levels of myocardial fibrosis marker genes,such as Col1 a1,Col3 a1,and Acta2,were de-tected using RT-qPCR.Results RICH1 was signifi-cantly down-regulated in TGF-β1-treated MCFs;the expression levels of myocardial fibrosis marker genes,such as Col1 a1,Col3a1,and Acta2,were down-regu-lated in the RICH1 OE+TGF-β1 group;and in the siRICH1+TGF-β1 group,myocardial fibrosis marker genes,such as Col1 a1,Col3a1 and Acta2 were up-regulated at the expression level;phosphorylated SMAD2(p-SMAD2)and phosphorylated SMAD3(p-SMAD3)levels were down-regulated in the siRICH1 OE+TGF-β1 group.p-SMAD2 and P-SMAD3 levels were upregulated in the siRICH1+TGF-β1 group.Conclusion RICH1 inhibits TGF-β1-induced myo-cardial fibrosis;RICH1 inhibits TGF-β1-induced myo-cardial fibrosis by negatively regulating the SMAD2/3 signaling pathway.
7.Relationship between Serum IGFBP-3,IGF-1 and Cardiac Function and Short-Term Prognosis in Patients with Dilated Cardiomyopathy Complicated with Heart Failure
Li-juan YUAN ; Shi-yuan XIE ; Yan ZHOU ; Fa-mao LI ; Yi-wu ZHENG
Progress in Modern Biomedicine 2025;25(9):1576-1583
Objective:To observe the relationship between serum insulin-like growth factor binding protein-3(IGFBP-3),insulin-like growth factor-1(IGF-1)and cardiac function and short-term prognosis in patients with dilated cardiomyopathy(DCM)complicated with heart failure(HF).Methods:102 patients with DCM complicated with HF were selected as study group and they were divided into good prognosis group and poor prognosis group based on prognosis,and 100 patients with simple DCM during the same period were selected as the control group.The cardiac function indicators[left ventricular end systolic volume(LVESV),left ventricular ejection fraction(LVEF),left ventricular end diastolic volume(LVEDV)]and serum IGFBP-3 and IGF-1 levels between the control group and the study group were compared.The correlation between cardiac function and IGFBP-3,IGF-1 was analyzed by pearson analysis.The serum IGFBP-3 and IGF-1 leveles between good prognosis group and poor prognosis group were compared,the correlation between prognosis and IGFBP-3,IGF-1 was analyzed by spearman.Receiver operating characteristic(ROC)curves were used to analyze the predictive value of serum levels of IGFBP-3 and IGF-1 alone and in combination for the short-term prognosis of DCM complicated with HF patients.Results:Compared with control group,study group had higher LVEDV,LVESV,IGFBP-3,IGF-1,and lower LVEF(P<0.05).Pearson analysis results showed that,IGFBP-3 and IGF-1 were positively correlated with LVEDV and LVESV,while which was negatively correlated with LVEF(P<0.05).Compared with good prognosis group,poor prognosis group had higher IGFBP-3,IGF-1(P<0.05).Spearman correlation analysis results showed that,the levels of IGFBP-3 and IGF-1 were positively correlated with the poor prognosis of DCM complicated with HF patients(P<0.05).The area under the curve(AUC)of serum IGFBP-3,IGF-1 levels,and their combined use for short-term prognosis of DCM complicated with HF patients were 0.715,0.749,and 0.831,respectively.Conclusion:Serum IGFBP-3 and IGF-1 levels are elevated in patients with DCM complicated with HF,and the changes in these two indicators are associated with poor cardiac function and prognosis in patients.The combined detection of IGFBP-3 and IGF-1 levels has a high predictive value for the short-term prognosis of DCM combined with HF.
8.The Effects of the Combination of Curcumin,Berberine,and Puerarin on Lipid Levels in Hyperlipidemic Mice
Zhi-yuan FAN ; Yi-zhou XU ; Si-wei XU ; Xiong-hua XING ; Mao-lin LIU ; Xia YI
Progress in Modern Biomedicine 2025;25(13):2100-2109,2099
Objective:To investigate the effects of curcumin,berberine,and puerarin combination therapy on lipid levels in hyperlipidemic mice.Methods:A total of 40 male C57BL/6J mice were randomly divided into eight groups:normal control group(A),high-fat control group(B),curcumin group(C),berberine group(D),puerarin group(E),low-dose combination group of curcumin,berberine,and puerarin(F),high-dose combination group of curcumin,berberine,and puerarin(G),and positive control group(H),with 5 mice in each group.The normal control group was fed a standard diet,while the other groups were given a high-fat diet.After establishing the hyperlipidemic model,the mice were administered with physiological saline,curcumin(200 mg/kg),berberine(200 mg/kg),puerarin(300 mg/kg),low-dose combination of curcumin(50 mg/kg),berberine(50 mg/kg),and puerarin(100 mg/kg),high-dose combination of curcumin(200 mg/kg),berberine(200 mg/kg),and puerarin(300 mg/kg),or simvastatin(6 mg/kg)via gavage for three weeks.After treatment,serum was collected from the mice for biochemical analysis of lipid levels and liver function.Liver tissues were subjected to HE staining,Western blot analysis and real-time quantitative PCR.Results:Curcumin,berberine,and puerarin,whether administered individually or in combination,can reduce the body weight of hyperlipidemic mice(P<0.01).Treatment with curcumin,berberine,and puerarin individually significantly reduced lipid levels in hyperlipidemic mice(P<0.05)and alleviated liver damage caused by hyperlipidemia(P<0.05).Furthermore,the high-dose combination of curcumin,berberine,and puerarin exhibited a more pronounced effect on improving lipid levels(P<0.01)and provided greater protective effects on the liver compared to the positive control group(P<0.05).Additionally,curcumin,berberine,and puerarin administered individually can each promote the expression of the LDLR gene in high-fat diet mice(increased by 90%,85%,and 98%,respectively)and reduce the expression of the ACC gene(decreased by 42%,45%,and 43%,respectively).The combination of all three compounds enhances the expression of the LDLR gene in high-fat diet mice(increased by 90%with low-dose combination and 169%with high-dose combination)and reduces the expression of the ACC gene(decreased by 38%with low-dose combination and 42%with high-dose combination).Conclusion:The combination of curcumin,berberine,and puerarin significantly improves lipid levels in hyperlipidemic mice and mitigates liver damage associated with hyperlipidemia.
9.Current Research and Development of Antigenic Epitope Prediction Tools
Zi-Hao LI ; Yuan WANG ; Tian-Tian MAO ; Zhi-Wei CAO ; Tian-Yi QIU
Progress in Biochemistry and Biophysics 2024;51(10):2532-2544
Adaptive immunity is a critical component of the human immune system, playing an essential role in identifying antigens and orchestrating a tailored immune response. This review delves into the significant strides made in the development of epitope prediction tools, their integration into vaccine design, and their pivotal role in enhancing immunotherapy strategies. The review emphasizes the transformative potential of these tools in refining our understanding and application of immune responses. Adaptive immunity distinguishes itself from innate immunity by its ability to recognize specific antigens and remember past infections, leading to quicker and more effective responses upon subsequent exposures. This facet of immunity involves complex interactions between various cell types, primarily B cells and T cells, which recognize distinct epitopes presented by antigens. Epitopes are small sequences or configurations on antigens that are recognized by the immune receptors on B cells and T cells, acting as the focal points of immune recognition and response. Epitopes can be broadly classified into two types: linear (or sequential) epitopes and conformational (or discontinuous) epitopes. Linear epitopes consist of a sequence of amino acids in a protein that are recognized by B cells and T cells in their primary structure form. Conformational epitopes, on the other hand, are formed by spatially distinct amino acids that come together in the tertiary structure of the protein, often recognized by the immune system only when the protein folds into its native conformation. The role of epitopes in the immune response is critical as they are the primary triggers for the activation of B cells and T cells. When an epitope is recognized, it can stimulate B cells to produce antibodies, mobilize helper T cells to secrete cytokines, or prompt cytotoxic T cells to kill infected cells. These actions form the basis of the adaptive immune response, tailored to eliminate specific pathogens or infected cells effectively. The prediction of B cell and T cell epitopes has evolved with advances in computational biology, leading to the development of several sophisticated tools that utilize a variety of algorithms to predict the likelihood of epitope regions on antigens. Tools employing machine learning methods, such as support vector machines (SVMs), XGBoost, random forest, analyze large datasets of known epitopes to classify new sequences as potential epitopes based on their similarity to known data. Moreover, deep learning has emerged as a powerful method in epitope prediction, leveraging neural networks capable of learning high-dimensional data from vast amounts of immunological inputs to identify patterns that may not be evident to other predictive models. Deep learning models, such as convolutional neural networks (CNNs), recurrent neural networks (RNNs) and ESM protein language model have demonstrated superior accuracy in mapping the nonlinear relationships inherent in protein structures and epitope interactions. The application of epitope prediction tools in vaccine design is transformative, enabling the development of epitope-based vaccines that can elicit targeted immune responses against specific parts of the pathogen. These vaccines, by focusing the immune response on highly specific regions of the pathogen, can offer high efficacy and reduced side effects. Similarly, in cancer immunotherapy, epitope prediction tools help identify tumor-specific antigens that can be targeted to develop personalized immunotherapeutic strategies, thereby enhancing the precision of cancer treatments. The future of epitope prediction technology appears promising, with ongoing advancements anticipated to enhance the precision and efficiency of these tools further. The integration of broader immunological data, such as patient-specific immune profiles and pathogen variability, along with advances in AI and machine learning, will likely drive the development of more adaptive, robust, and clinically relevant prediction models. This will not only improve the effectiveness of vaccines and immunotherapies but also contribute to our broader understanding of immune mechanisms, potentially leading to breakthroughs in the treatment and prevention of multiple diseases. In conclusion, the development and refinement of epitope prediction tools stand as a cornerstone in the advancement of immunological research and therapeutic design, highlighting a path toward more precise and personalized medicine. The ongoing integration of computational models with experimental immunology holds the promise of revolutionizing our approach to combating infectious diseases and cancer.
10.Effect and mechanism of dexmedetomidine on alleviating heat stroke related rhabdomyolysis in rats
Cheng-Cheng LI ; Yang LIU ; Han-Ding MAO ; Li-Na ZHAO ; Shu-Yuan LIU ; Yi SHAN
Medical Journal of Chinese People's Liberation Army 2024;49(8):922-929
Objective To explore whether dexmedetomidine(DEX)can alleviate exertional heatstroke(EHS)-induced rhabdomyolysis(RM)in rats by activating adrenergic α2 receptors,and to explore its potential mechanism based on the reactive oxygen species(ROS)/NOD-like receptor protein 3(NLRP3)/interleukin-1β(IL-1β)pathway.Methods Thirty-six male Sprague-Dawley(SD)rats,after a 7-day acclimatization training,were randomly divided into six groups:control group(CN group),EHS group,low-dose DEX group(EHS+low DEX group),high-dose DEX group(EHS+high DEX group),DEX combined with yohimbine(YOH)group(EHS+high DEX+YOH group),and YOH group(EHS+YOH),with six rats in each group.Before modeling,EHS+high DEX+YOH group and EHS+YOH group were intraperitoneally injected with YOH at 1 mg/kg,while the other four groups were injected intraperitoneally with an equal dose of physiological saline(0.9%NS).During modeling,except for CN group,the other 5 groups of rats were subjected to heat exercise in a high-temperature and high-humidity chamber to construct an EHS rat model.After successful modeling,EHS+low DEX group was intraperitoneally injected with DEX at 10 μg/kg,EHS+high DEX group and EHS+high DEX+YOH group were intraperitoneally injected with DEX at 30 μg/kg,and CN group,EHS group and DEX+YOH group were intraperitoneally injected with equal doses of saline.After 6 h of observation,all rats were anesthetized,and their blood from the abdominal aorta and gastrocnemius muscle tissue were taken.Enzyme-linked immunosorbent assay(ELISA)was used to detect the expression levels of serum tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-1β and myoglobin(MB)in rats;biochemical assay kit was used to measure the level of creatine kinase(CK)in rat serum;HE staining was used to observe pathological changes in rat gastrocnemius muscle tissues;transmission electron microscopy was used to observe ultrastructural changes in gastrocnemius muscle;2′,7′-dichlorofluorescent yellow diacetate(DCFH-DA)fluorescent probe was used to detect the level of reactive oxygen species(ROS);and Western blotting was performed to detect the expression levels of NOD-like receptors 3(NLRP3),aspartic protease-1(caspase-1)and adrenergic α2A receptor(ADRA2A).Results Compared with CN group,the levels of serum IL-6,IL-1β,TNF-α,CK and MB in EHS group rats were significantly elevated(P<0.01).HE staining results revealed that the gastrocnemius muscle tissues of rats in EHS group had these pathological manifestations such as disarray of muscle fibrous structure,hemorrhage,edema,and infiltration of inflammatory cells.Transmission electron microscopy results showed that the ultrastructure of the gastrocnemius muscle in EHS group exhibited myofibroblasts with swelling and enlarging in size,cytoplasmic vacuolization,and mitochondria with obvious swelling,degranulation,and disappearance of double cristae.Compared with CN group,the expression levels of ROS,NLRP3,and caspase-1 in gastrocnemius of rats in EHS group significantly increased(P<0.01);Compared with EHS group,the levels of TNF-α,IL-6,IL-1β,CK,MB and the expression levels of ROS,NLRP3,caspase-1 in gastrocnemius tissue of rats in EHS+low DEX group and EHS+high DEX group decreased in a dose-dependent manner(P<0.05),and the pathological damage observed with HE staining and transmission electron microscopy was alleviated by DEX.After YOH pretreatment,compared with the EHS+high DEX group,the serum levels of TNF-α,IL-6,IL-1β,CK,MB and ROS,NLRP3 and caspase-1 in the gastrocnemius muscle tissue of rats in EHS+high DEX+YOH group relatively increased(P<0.05),and the pathological damage observed with HE staining and transmission electron microscopy was exacerbated.The expression of ADRA2A in gastrocnemius muscle of EHS group significantly decreased compared with CN group(P<0.01),and the expression of ADRA2A in muscle of rats in DES+low DEX group and EHS+high DEX group was higher than that in EHS group(P<0.05).Conclusions DEX can alleviate EHS-induced RM by activating ADRA2A,potentially through inhibiting the ROS-dependent NLRP3/IL-1β inflammatory pathway.

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