1.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.
2.Medicinal properties and compatibility application of aromatic traditional Chinese medicine monomer components based on action of volatile components against viral pneumonia.
Yin-Ming ZHAO ; Lin-Yuan WANG ; Jian-Jun ZHANG ; Chun WANG ; Yi LI ; Xiao-Fang WU ; Qi ZHANG ; Xing-Yu ZHAO ; Lin-Ze LI ; Rui-Lin LYU
China Journal of Chinese Materia Medica 2025;50(8):2013-2021
Aromatic traditional Chinese medicine(TCM) has played an important role against epidemics and viruses, and volatile components are the main components that exert the pharmacological effects of aromatic TCM. By screening the related monomer components in aromatic TCM against epidemic and viruses and analyzing and endowing TCM with medicinal properties based on its clinical application and pharmacological research according to the theoretical thinking of TCM, the key technical issues of compatibility of TCM monomer components were solved from a theoretical perspective, providing new ideas and methods for screening raw materials and formulas for the development of new TCM drugs. Based on the conditions of antiviral activity, clinical application foundation, definite therapeutic effect, and high safety, a gradient screening of aromatic TCM was carried out. Firstly, 30 aromatic TCM were screened from anti-epidemic literature and clinical trial formulas, and seven volatile monomers were further screened from them. Then, four monomer components with significant effects, namely patchouli alcohol, carvacrol, p-cymene, and eucalyptol were screened. By adopting the "four-step method for a systematic study of TCM properties", the four monomer components were endowed with medicinal properties, and compatibility and combination studies were conducted to explore the theoretical basis of monomer formulas and form monomer formulas guided by TCM theory. The screening results of volatile monomers in aromatic TCM against viral pneumonia included patchouli alcohol, carvacrol, p-cymene, and eucalyptol. The medicinal properties and compatibility theory of volatile monomer components in TCM were explored. Patchouli alcohol was the main herb, with a cool and pungent nature. It entered the lung meridian to dispel evil Qi and has the effects of aromatization, detoxification, and epidemic prevention. Carvacrol was a minister drug with a cool and pungent taste. It had the effects of aromatizing, moistening, and dissolving the exterior, as well as strengthening the spleen and stomach. p-Cymene was an adjunctive medicine with a mild and pungent nature. It entered the lungs and kidneys and had the effects of aromatic purification, cough relief, and asthma relief. Eucalyptol was also an adjunctive medicine with a pungent and warm taste. It had the functions of aromatic purification, cough relief, phlegm reduction, and pain relief. The combination of the four medicines had the effects of aromatizing, moistening, detoxifying, and epidemic prevention, as well as relieving cough and asthma and strengthening the spleen and stomach. They were used to treat viral pneumonia caused by upper respiratory tract viral infections, with symptoms such as chest tightness, cough, wheezing, fatigue, nasal congestion, runny nose, nausea, and vomiting. This study has laid a literature and theoretical foundation for further drug efficacy verification experiments, compatibility efficacy experiments, and subsequent product development and clinical applications, and it serves as an innovative practice that combines literature research, theoretical research, experimental research, and clinical practice to develop new products.
Drugs, Chinese Herbal/therapeutic use*
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Antiviral Agents/pharmacology*
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Humans
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Pneumonia, Viral/virology*
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Medicine, Chinese Traditional
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Volatile Organic Compounds/pharmacology*
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Animals
3.Influence of eucalyptol on biological effects of spleen cold and spleen heat syndromes in rats and mechanism of regulating spleen channel with its warm nature based on TRP ion channel.
Xing-Yu ZHAO ; Yi LI ; Xiao-Fang WU ; Qi ZHANG ; Lin-Ze LI ; Yin-Ming ZHAO ; Chun WANG ; Jian-Jun ZHANG ; Lin-Yuan WANG
China Journal of Chinese Materia Medica 2025;50(8):2022-2031
This paper aims to investigate the influence of eucalyptol on the biological effects of spleen cold and spleen heat syndromes in rats and its regulation of transient receptor potential vanilloid 1(TRPV1), transient receptor potential melastatin 8(TRPM8), and uncoupling protein 1(UCP1), so as to explore the cold-heat properties of eucalyptol. Rats were randomly divided into groups as follows: blank group, spleen cold syndrome model group, spleen cold syndrome+Atractylodis Rhizoma group, spleen cold syndrome + low-dose eucalyptol group, and spleen cold syndrome+high-dose eucalyptol group, as well as blank group, spleen heat syndrome model group, spleen heat syndrome+Coptidis Rhizoma group, spleen heat syndrome + low-dose eucalyptol group, and spleen heat syndrome + high-dose eucalyptol group. Spleen cold and spleen heat syndromes were induced by disorders of hunger and satiety combined with bitter cold drugs, as well as a high-fat diet combined with liquor. Except for the blank and model groups, the other groups were administered once a day during the modeling process for 14 consecutive days. The general condition and body weight of rats in each group were observed, and the histopathological morphology of the gastric antrum and small intestine was observed by hematoxylin-eosin(HE) staining. The contents of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), Na~+-K~+-ATPase, total cholesterol(TC), triglyceride(TG), gastrin(GAS), motilin(MTL), D-xylose, and other related indices were detected in rats. The expression levels of TRPV1, TRPM8, and UCP1 in small intestine tissue of rats with spleen cold syndrome were detected. The results showed that eucalyptol had a certain degree of improvement in the overall state and body weight of rats with spleen cold syndrome. Compared with the spleen cold syndrome model group, high-dose eucalyptol significantly increased the levels of serum cAMP, cAMP/cGMP, TG, and TC in rats with spleen cold syndrome(P<0.05, P<0.01), decreased the content of cGMP, and significantly elevated the levels of gastrointestinal function-related indicators GAS, MTL, and D-xylose(P<0.05, P<0.01). Low-dose eucalyptol significantly increased the level of cAMP/cGMP in the serum and Na~+-K~+-ATPase levels in hepatic tissue(P<0.05, P<0.01), and significantly increased the levels of GAS and D-xylose(P<0.01). Eucalyptol showed similar effects to Atractylodis Rhizoma with a warm nature on rats with spleen cold syndrome. Compared with the spleen heat syndrome model group, the high-dose and low-dose eucalyptol groups showed a trend of increase in gastrointestinal indicators, with no significant changes in other indicators. In addition, high-dose eucalyptol increased the expression of TRPV1 and UCP1 and decreased the expression of TRPM8 in the small intestine tissue of rats with spleen cold syndrome. Eucalyptol could affect the cyclic nucleotide and material energy metabolism levels of rats with spleen cold syndrome and had a certain improvement effect on their gastrointestinal digestion and absorption function, thereby improving spleen cold syndrome. Eucalyptol had no significant improvement effect on rats with spleen heat syndrome, suggesting that eucalyptol may have a warm nature and regulate spleen meridians. It is speculated that eucalyptol may exhibit its medicinal properties by activating the TRPV1 pathway, promoting the expression of UCP1, and inhibiting the TRPM8 channel.
Animals
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Rats
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Spleen/metabolism*
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Male
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TRPV Cation Channels/genetics*
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Rats, Sprague-Dawley
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Eucalyptol/administration & dosage*
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TRPM Cation Channels/genetics*
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Uncoupling Protein 1/genetics*
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Humans
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Drugs, Chinese Herbal/administration & dosage*
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Cold Temperature
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Cyclic GMP/metabolism*
4.Medicinal properties and mechanisms of p-cymene with mild and warm nature based on deficiency-cold and deficiency-heat syndrome models.
Xiao-Fang WU ; Yi LI ; Xing-Yu ZHAO ; Lin-Ze LI ; Qi ZHANG ; Yin-Ming ZHAO ; Ying-Li ZHU ; Chun WANG ; Jian-Jun ZHANG ; Lin-Yuan WANG
China Journal of Chinese Materia Medica 2025;50(8):2032-2040
This paper aims to study the effect of p-cymene on mice with deficiency-cold syndrome induced by hydrocortisone and deficiency-heat syndrome induced by dexamethasone and explore the medicinal properties and mechanism of p-cymene with mild and warm nature based on the dominant characteristics of the two-way applicable conditions of mild drugs. A total of 80 KM mice were randomly divided into blank group, deficiency-cold syndrome model group, deficiency-cold syndrome + ginseng group, and deficiency-cold syndrome + low-dose and high-dose p-cymene groups, as well as blank group, deficiency-heat syndrome model group, deficiency-heat syndrome + American ginseng group, and deficiency-heat syndrome + low-dose and high-dose p-cymene groups. Hydrocortisone and dexamethasone solution were intragastrically administered for 14 consecutive days to prepare deficiency-cold syndrome and deficiency-heat syndrome models. Except for the blank group and the model group intragastrically administered with normal saline, the other groups were intragastrically administrated with drugs for 14 days. The levels of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), total cholesterol(TC), triglyceride(TG), immunoglobin G(IgG), and immunoglobin M(IgM) in serum, as well as the activity of Na~+-K~+-ATPase in liver tissue were detected. The expression of transient receptor potential melastatin 8(TRPM8), transient receptor potential vanilloid 1(TRPV1), and uncoupling protein 1(UCP1) in brown adipose tissue of deficiency-cold syndrome model after intervention with p-cymene was studied. The results showed that p-cymene could effectively improve the levels of cAMP, cAMP/cGMP, TC, IgM, and IgG in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and reduce the content of cGMP. The effects on T3, T4, and TG were not statistically significant. At the same time, p-cymene could reduce the levels of cAMP, cAMP/cGMP, and T4 in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and increase the levels of cGMP, IgM, and IgG, and it had no effect on T3, TC, and TG. In addition, p-cymene could up-regulate the expression of TRPV1 and UCP1 in brown fat of mice with deficiency-cold syndrome and down-regulate the expression of TRPM8. In summary, p-cymene could significantly regulate the syndrome indexes of mice with deficiency-cold syndrome, and some indexes of mice with deficiency-heat syndrome could be improved, but the effects on lipid metabolism and energy metabolism indexes were not obvious, indicating that the regulation effect of p-cymene on deficiency-cold syndrome model was more prominent and that the medicinal properties of p-cymene were mild and warm. The regulation of TRPV1/TRPM8/UCP1 channel expression may be the molecular biological mechanism of p-cymene with mild and warm nature affecting the energy metabolism of the body.
Animals
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Cymenes
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Mice
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Drugs, Chinese Herbal/administration & dosage*
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Male
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Disease Models, Animal
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Humans
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Cyclic AMP/metabolism*
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Monoterpenes/administration & dosage*
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Liver/metabolism*
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Cyclic GMP/metabolism*
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TRPV Cation Channels/genetics*
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Uncoupling Protein 1/genetics*
5.Diagnostic and treatment strategies for testicular torsion.
Qing-Song MENG ; Wan-Ze ZHANG ; Ming ZHANG ; Jiang-Hua JIA ; Xin WANG ; Wan-Li MA ; Yao-Hua WANG ; Ya-Xuan WANG
National Journal of Andrology 2025;31(3):222-225
OBJECTIVE:
To investigate the differences between high-frequency ultrasound-guided manual detorsion combined with surgery (MD+S) and surgery alone in the treatment of testicular torsion, and to provide some new evidence for the timely diagnosis and treatment of the disease.
METHODS:
We retrospectively analyzed the clinical data on 134 cases of unilateral testicular torsion within 48 hours treated in our hospital by MD+S or by surgery alone from January 2015 to May 2022. We statistically analyzed the age distribution, and duration and degrees of testicular torsion, followed by comparison between the two groups.
RESULTS:
In the 134 cases, the median age of onset was 15 (13-19) years old, the median onset-to-visit time was 15 (8-25) hours, and the median degree of torsion was 360° (180°-1080°). Of the total number of patients, 21 underwent testicular excision and the other 113 were treated with the testis preserved, with no statistically significant difference in age distribution between the two groups (P>0.05), and a higher rate of testis resection in those with longer duration and greater angle of torsion (P<0.05). Totally, 33 of the patients were assigned to the MD+S group and 101 to the surgery alone group. According to the actual clinical conditions and excluding those with torsion time longer than 24 hours and torsion angle greater than 720 °, 28 of the patients underwent ultrasound-guided MD+S (with 1 case of testis resection, 3.6%), and 68 received surgery alone (with 7 cases of testis resection, 10.3%). The rate of testis resection was higher in the surgery alone than that in the MD+S group, but with no statistically significant difference between the two groups (P>0.05), which was considered to be related to the small sample size in this study.
CONCLUSION
The popularization of testicular torsion knowledge can shorten the onset-to-visit time, and reasonable manual detorsion before emergency surgery can reduce the rate of testis resection.
Humans
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Male
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Spermatic Cord Torsion/therapy*
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Retrospective Studies
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Adolescent
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Young Adult
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Ultrasonography
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Testis/surgery*
;
Adult
6.Variation rules of main secondary metabolites in Hedysari Radix before and after rubbing strip
Xu-Dong LUO ; Xin-Rong LI ; Cheng-Yi LI ; Peng QI ; Ting-Ting LIANG ; Shu-Bin LIU ; Zheng-Ze QIANG ; Jun-Gang HE ; Xu LI ; Xiao-Cheng WEI ; Xiao-Li FENG ; Ming-Wei WANG
Chinese Traditional Patent Medicine 2024;46(3):747-754
AIM To investigate the variation rules of main secondary metabolites in Hedysari Radix before and after rubbing strip.METHODS UPLC-MS/MS was adopted in the content determination of formononetin,ononin,calycosin,calycosin-7-glucoside,medicarpin,genistein,luteolin,liquiritigenin,isoliquiritigenin,vanillic acid,ferulic acid,γ-aminobutyric acid,adenosine and betaine,after which cluster analysis,principal component analysis and orthogonal partial least squares discriminant analysis were used for chemical pattern recognition to explore differential components.RESULTS After rubbing strip,formononetin,calycosin,liquiritigenin and γ-aminobutynic acid demonstrated increased contents,along with decreased contents of ononin,calycosin-7-glucoside and vanillic acid.The samples with and without rubbing strip were clustered into two types,calycosin-7-glucoside,formononetin,γ-aminobutynic acid,vanillic acid,calycosin-7-glucoside and formononetin were differential components.CONCLUSION This experiment clarifies the differences of chemical constituents in Hedysari Radix before and after rubbing strip,which can provide a reference for the research on rubbing strip mechanism of other medicinal materials.
7.Nanomaterial-based Therapeutics for Biofilm-generated Bacterial Infections
Zhuo-Jun HE ; Yu-Ying CHEN ; Yang ZHOU ; Gui-Qin DAI ; De-Liang LIU ; Meng-De LIU ; Jian-Hui GAO ; Ze CHEN ; Jia-Yu DENG ; Guang-Yan LIANG ; Li WEI ; Peng-Fei ZHAO ; Hong-Zhou LU ; Ming-Bin ZHENG
Progress in Biochemistry and Biophysics 2024;51(7):1604-1617
Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.
8.Role of TGF-β/Smads signaling pathway in myocardial fibrosis of heart failure and research status of traditional Chinese medicine intervention
Yao-Hui HUO ; Jing ZHANG ; Li-Rong ZHOU ; Xiao-Gang ZHANG ; Yong-Ze GAO ; Li-Ming LIU ; Kai LIU
The Chinese Journal of Clinical Pharmacology 2024;40(3):444-448
During the progression of heart failure(HF),abnormal transduction of the transforming growth factor-β(TGF-β)/Smads signaling pathway is important mechanism of myocardial fibrosis(MF)in HF.TGF-β,a key factor in MF,is in an overexpression state in the process of MF in HF,and Smads is a major effector downstream of TGF-β.The TGF-β/Smads pathway induces abnormal proliferation of myofibroblasts,aggravates myocardial extracellular matrix deposition,and reduces the ability of the cardiac tissues to resist fibrosis,which plays a complex role in the pathogenesis of MF in HF.Traditional Chinese medicine(TCM)has the efficacy of unequivocal inhibiting myocardial collagen deposition,anti-MF,protecting the myocardium and improving cardiac function in the prevention and treatment of MF in HF and so on,and the TGF-β/Smads pathway is one of the key pathways through which TCM monomers,TCM combinations,and proprietary medicines can exert their cardioprotective effects on the HF.This paper reviews the existing experimental research results of TCM intervening in the TGF-β/Smads pathway for the treatment of MF in HF over the past 10 years,with a view to providing theoretical basis for the prevention and treatment of HF MF well as the development and of new drugs.
9.Effects of 5'-N-ethylocarbo-xamidoad-enosine on brain ischemia-reperfusion oxidative injury and levels of miR-29b and miR-125b in rats
Ze LI ; Jun TAN ; Qiu-Li MING ; Yan-Wei LI
The Chinese Journal of Clinical Pharmacology 2024;40(10):1448-1452
Objective To investigate the effects of 5'-N-ethylocarbo-xamidoad-enosine(NECA)on cerebral ischemia-reperfusion oxidative injury and the levels of miR-29b and miR-125b in rats.Methods SD rats were divided into sham-operation,model,experimental and positive control groups with 12 rats in each group.Cerebral ischemia-reperfusion model was established in all the other 3 groups except control group.7 days before modeling,sham-operation group and model group were intraperitoneally injected with the same amount of normal saline,and experimental group was injected with 1.5 mg·kg-1 NECA,and positive control group was injected with 2.0 mg·kg-1 nimodipine.The rats in 4 groups were given the drug once a day for 7 days.Cerebral ischemia-reperfusion model was established by middle cerebral artery embolization in all the other 3 groups except sham-operation group.After the modeling was successful,the serum oxidative stress indexes glutathione(GSH),superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA)of rats were determined by enzyme-linked immunosorbent assay,and the levels of miR-29b and miR-125b in brain tissue were detected by real-time fluorescence quantitative polymerase chain reaction.Results The SOD levels of sham-operation,model,experimental and positive control groups were(57.82±6.87),(10.75±0.24),(32.24±3.42)and(29.45±4.11)U·mL-1;the levels of GSH were(20.62±3.12),(9.45±1.92),(16.78±1.85)and(15.39±2.02)U·mg-1;the levels of CAT were(3.25±0.42),(0.85±0.11),(2.18±0.34)and(1.98±0.32)U·L-1;the levels of MDA were(0.42±0.09),(1.35±0.42),(0.75±0.06)and(0.72±0.08)nmol·mg-1;the expression levels of miR-29b in brain tissue were 1.02±0.11,0.42±0.02,0.84±0.08 and 0.87±0.10;the expression levels of miR-125b in brain tissue were 1.00±0.11,0.48±0.05,0.75±0.08 and 0.74±0.07,respectively.There were statistically significant differences between sham-operation group and model group(all P<0.05).Compared with experimental group and positive control group,there were statistically significant differences in the above indexes(all P<0.05).Conclusion NECA can improve oxidative damage and increase the expression levels of miR-29b and miR-125b in cerebral ischemia-reperfusion rats.
10.Immunological characteristics of the PhoP protein of two-component system in Mycobacterium tuberculosis
Xue LI ; Huan-Huan NING ; Jian KANG ; Ming-Ze XU ; Ruo-Nan CUI ; Ting DAI ; Yan-Zhi LU ; Sa XUE ; Yin-Lan BAI
Chinese Journal of Zoonoses 2024;40(4):352-358
In this study,the immunological characteristics of the PhoP protein were explored with a two-component system of Mycobacterium tuberculosis(Mtb).Bioinformatics was used to predict the B and T cell epitopes of the PhoP protein.A re-combinant expression plasmid was constructed by PCR analysis of the phoP sequence and cloning into the prokaryotic expres-sion vector pET-28a(+).Competent Escherichia coli BL21 cells were transformed with the recombinant plasmid and expres-sion was induced with IPTG.The recombinant PhoP protein was purified by affinity chromatography.Serum levels of PhoP-specific antibodies in Mtb-infected mice and tuberculosis(TB)patients were analyzed with an ELISA.BALB/c mice were im-munized with the PhoP recombinant protein by intramuscular injection.Sera of mice were collected and antibody titers were detected with an ELISA and specificity was assessed by West-ern blot analysis.Mouse splenocytes were isolated and the pro-portions of IFN-y-positive cells and cytokine levels were detec-ted with an ELISpot and ELISA,respectively.Bioinformatics i-dentified 24 B cell and 11 T cell epitopes of the PhoP protein.A prokaryotic recombinant vector of PhoP was successfully con-structed and the recombinant PhoP protein was obtained by purification.Specific antibody levels to PhoP in sera of Mtb in-fected mice and TB patients increased significantly,with preci-sion of 99.9%and 82.5%,and specificity of 100%,respectively.PhoP protein immunization successfully induced production of specific antibodies in mice.Stimulated by antigens in vitro,IL-2 and IFN-γ levels were significantly increased in the splenocytes of immunized mice.Immunization with the PhoP protein induce a humoral immune response and Thl-dominated cellular immu-nity,indicating that the PhoP protein was immunogenic with diagnostic efficacy for TB.These results lay a foundation to clari-fy the role of PhoP in Mtb infection and application for diagnosis and prevention of TB.

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