1.Human umbilical cord mesenchymal stem cell-derived exosomes attenuate renal ischemia-reperfusion injury by up-regulating ATF3 to inhibit the TLR4/NF-κB pathway
Xingyu* WAN ; Yujia LIU ; Ruiyan WANG ; Hao WANG ; Yi ZHAO ; Lu GUO ; Zhihua YANG ; Xinghua LÜ
Organ Transplantation 2026;17(2):275-286
Objective To investigate the protective effect and underlying mechanism of human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Exo) on renal ischemia-reperfusion injury (IRI). Methods hucMSC-Exos were isolated and characterized. A mouse renal IRI model was established and the animals were divided into Sham, IRI, IRI+hucMSC-Exo, IRI+hucMSC-Exo+JY-2 and Sham+JY-2 groups. Serum creatinine (Scr) and blood urea nitrogen (BUN) were measured. Hematoxylin-eosin (HE) staining was used to evaluate renal histopathology. Enzyme-linked immune absorbent assay was performed to determine serum interleukin (IL)-1β and IL-18 levels. Western blotting was used to detect the expression of activating transcription factor 3 (ATF3), Toll-like receptor 4 (TLR4), nuclear factor (NF)-κB, NOD-like receptor protein 3 (NLRP3), cysteineyl aspartate specific proteinase (Caspase)-1 p20 and Gasdermin D(GSDMD). Real-time fluorescent quantitative polymerase chain reaction was employed to measure ATF3, TLR4 and NF-κB messenger RNA (mRNA). Immunohistochemistry was conducted to examine NLRP3, Caspase-1 p20 and GSDMD. An in vitro hypoxia/reoxygenation (H/R) model was established in HK-2 cells and divided into Control, H/R, H/R+hucMSC-Exo, H/R+hucMSC-Exo+JY-2 and Control+JY-2 groups. Western blotting was used to detect the expression of ATF3, TLR4 and NF-κB. Real-time fluorescent quantitative polymerase chain reaction was used to measure NLRP3, GSDMD and Caspase-1 mRNA. Results HucMSC-Exos were successfully isolated and identified. Compared with the Sham group, the IRI group exhibited elevated Scr and BUN, higher tubular injury scores, increased protein expression levels of ATF3, TLR4, NF-κB p65, NLRP3, Caspase-1 p20 and GSDMD, and raised mRNA expression levels of ATF3, TLR4, NF-κB. Compared with the IRI group, the IRI+hucMSC-Exo group showed decreased Scr and BUN, lower tubular injury scores, up-regulated ATF3 protein and mRNA, down-regulated TLR4, NF-κB p65, NLRP3, Caspase-1 p20 and GSDMD protein, and declined TLR4 and NF-κB mRNA. Compared with the IRI+hucMSC-Exo group, the IRI+hucMSC-Exo+JY-2 group exhibited increased Scr and BUN levels, elevated renal tubular injury scores, decreased ATF3 protein expression levels, elevated protein expression levels of TLR4, NF-κB p65, NLRP3, Caspase-1 p20, and GSDMD, decreased ATF3 mRNA expression levels, and elevated mRNA expression levels of TLR4 and NF-κB. (all P < 0.05). Compared with the Control group, the expression levels of ATF3, TLR4 and NF-κB p65 proteins were increased in the H/R group, and the expression levels of NLRP3, Caspase-1 and GSDMD mRNA were increased. Compared with the H/R group, the expression level of ATF3 protein was increased, the expression levels of TLR4 and NF-κB p65 proteins were decreased, and the expression levels of NLRP3, Caspase-1 and GSDMD mRNA were decreased in the H/R+hucMSC-Exo group. Compared with the H/R+hucMSC-Exo group, the expression level of ATF3 protein was decreased, the expression levels of TLR4 and NF-κB p65 proteins were increased, and the expression levels of NLRP3, Caspase-1 and GSDMD mRNA were increased in the H/R+hucMSC-Exo+JY-2 group (all P < 0.05). Conclusions HucMSC-Exos alleviate renal IRI by up-regulating ATF3, thereby negatively regulating the TLR4/NF-κB signaling pathway and subsequently inhibiting pyroptosis.
2.Introduction and enlightenment of the Recommendations and Expert Consensus for Plasma and Platelet Transfusion Strategies in Critically Ill Children Following Severe Trauma, Traumatic Brain Injury, and/or Intracranial Hemorrhage: From the Transfusion and Anemia Expertise Initiative-Control/Avoidance of Bleeding
Zhenzhen JIANG ; Rong GUI ; Rong HUANG ; Junhua ZHANG ; Jiaohui ZENG ; Hao TANG ; Zhi LIN ; Dan WAN ; Mingyi ZHAO ; Minghua YANG ; Lan GU ; Haiting LIU
Chinese Journal of Blood Transfusion 2026;39(2):285-293
Transfusion and Anemia Expertise Initiative-Control/Avoidance of Bleeding developed a strategy for platelet and plasma infusion management in critically ill children based on systematic reviews and consensus meetings of international multidisciplinary experts. One good practice statement and six expert consensus statements were proposed for plasma and platelet transfusions in critically ill children following severe trauma, traumatic brain injury, and/or intracranial hemorrhage. This article introduces the specific methods and basis for the formation of recommendations in this part of the guide.
3.Iron Homeostasis Imbalance Promotes Atherosclerosis and Therapeutic Mechanisms of Traditional Chinese Medicine
Maohong WANG ; Jianhua XIONG ; Hao ZHANG ; Xiaohong YAN ; Qiang WAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(19):279-286
Iron is an indispensable trace element for the human body to maintain normal physiological functions, widely participating in key processes such as oxygen transport, energy metabolism, and cell signal transduction. The homeostasis of iron is crucial for maintaining the structural integrity and functional stability of the cardiovascular system. Recent studies have shown that iron homeostasis imbalance, especially iron overload, has become a major risk factor for the occurrence and development of atherosclerosis (AS). The downstream-induced ferroptosis can form a "iron overload-lipid peroxidation-inflammation" vicious triangle through multiple pathways such as promoting oxidative stress, lipid peroxidation, and inflammatory response, and the three mutually reinforce each other to accelerate plaque formation and progression. Traditional Chinese medicine (TCM) has demonstrated unique advantages in the prevention and treatment of AS, with definite clinical efficacy. Its mechanism of action, in addition to improving lipid metabolism and protecting vascular endothelium, is closely related to the regulation of iron homeostasis in the body. From the new perspectives of systemic iron homeostasis imbalance and the "iron overload-lipid peroxidation-inflammation" vicious triangle, this article reviews the research progress in the association between iron homeostasis imbalance and AS in recent years, and integrate the mechanism of iron homeostasis imbalance in modern medicine with the TCM theory of stasis and toxin interconnection. It focuses on exploring the potential molecular mechanisms of TCM in regulating iron homeostasis through intervention in key pathways of iron overload and inhibition of ferroptosis, summarizes the "iron reduction-antioxidation-anti-inflammation" network constructed by TCM compound prescriptions, and the characteristics of TCM active components in synergistically resisting systemic iron homeostasis imbalance through sharing key targets such as nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor (NF)-κB. This article provides ideas and a theoretical basis that combine the characteristics of TCM theory with modern scientific evidence for the prevention and treatment of AS.
4.Xuefu Zhuyu Mixture Ameliorates Myocardial Injury in Coronary Heart Disease Rats by Modulating TLR4/PI3K/AKT/mTOR Signaling Pathway
Hao ZHU ; Lijuan HU ; Jing WAN
Journal of Guangzhou University of Traditional Chinese Medicine 2025;42(10):2539-2548
Objective To investigate the therapeutic effects and mechanisms of Xuefu Zhuyu Mixture(XFZY)in rats with coronary heart disease(CHD).Methods A CHD rat model was established.Successfully modeled rats were randomly divided into five groups(n=12 each):model group,Lipitor group,low-dose XFZY group(7.02 g·kg-1·d-1),high-dose XFZY group(14.04 g·kg-1·d-1),and high-dose XFZY+RS09[Toll-like receptor 4(TLR4)agonist]group(14.04 g·kg-1·d-1 XFZY+intraperitoneal RS09),with an additional normal control group(n=12).After treatment,following treatment completion,all rats underwent echocardiography to assess left ventricular end-diastolic diameter(LVDd),end-systolic diameter(LVDs),ejection fraction(LVEF),and fractional shortening(FS).Myocardial histopathology and vascular remodeling indices were evaluated via hematoxylin-eosin(HE)staining,while myocardial fibrosis was examined using Masson's trichrome staining.Enzyme-linked immunosorbent assay(ELISA)was employed to quantify inflammatory cytokine levels[tumor necrosis factorα(TNF-α),interleukin(IL)-1β,and IL-6]in myocardial tissues.Immunohistochemical analysis determined protein expression of B-cell lymphoma-2(Bc12)and Caspase 3 in myocardial tissues.Western Blot was performed to measure myocardial protein expression levels of TLR4,phosphatidylinositol 3-kinase(PI3K),phosphorylated protein kinase B(p-AKT),total AKT,phosphorylated mammalian target of rapamycin(p-mTOR),and total mTOR.Results Compared with the normal group,rats in the model group exhibited severe myocardial tissue damage,along with significantly elevated collagen volume fraction,LVDs,LVDd,myocardial levels of IL-6,TNF-α and IL-1β,cardiomyocyte apoptosis ratio,aortic media thickness,and protein expression of Caspase 3,TLR4,PI3K,p-AKT/AKT and p-mTOR/mTOR in myocardial tissue(P<0.05).Conversely,LVEF,FS,aortic luminal diameter,and Bcl-2 protein content were significantly reduced,the difference being statistically significant(P<0.05).Compared to the model group,both low-and high-dose XFZY groups as well as the Lipitor group demonstrated attenuated myocardial lesions,with significant reductions in collagen volume fraction,LVDs,LVDd,myocardial IL-6,TNF-α,IL-1β levels,cardiomyocyte apoptosis ratio,aortic media thickness,and protein expression of Caspase 3,TLR4,PI3K,p-AKT/AKT and p-mTOR/mTOR(P<0.05).Concurrently,LVEF,FS,aortic luminal diameter,and Bcl-2 protein content were significantly increased,the difference being statistically significant(P<0.05).No statistically significant differences were observed between the high-dose XFZY group and the Lipitor group for any aforementioned parameters(P>0.05).However,rats treated with high-dose XFZY plus RS09 showed aggravated myocardial injury with manifested interstitial fibrosis,alongside significantly intensified inflammatory response,cardiomyocyte apoptosis,and vascular remodeling compared to the high-dose XFZY alone group(all P<0.05).Conclusion XFZY alleviates CHD symptoms by suppressing TLR4/PI3K/AKT/mTOR pathway activation,thereby reducing myocardial inflammation,fibrosis,apoptosis,and vascular remodeling.
5.Inhibitory Effects of the Deep Underground Low Background Radiation Environment on the Proliferation and Migration of NP69 Human Nasopharyngeal Epithelial Cells and the Underlying Mechanisms
Zhizhen HAO ; Can LI ; Ling WANG ; Yuhao ZOU ; Jirui WEN ; Jiang WU ; Xuehong WAN ; Feng LIU ; Jifeng LIU
Journal of Sichuan University (Medical Sciences) 2025;56(5):1336-1343
Objective To investigate the effects of low background radiation environments in deep underground settings on the biological behavior of NP69 human nasopharyngeal epithelial cells(NP69 cells)and the underlying molecular mechanisms.Methods A parallel control experimental design was adopted and NP69 cells were synchronously cultured in settings of three underground depths at the China in situ Deep-Underground Facility&Life Observatory(DeUFO)—ground level(DeUFO-0 m),1 000 m underground(DeUFO-1 000 m),and 1 500 m underground(DeUFO-1 500 m).Changes in cell proliferation and migration capabilities were assessed using the Cell Counting Kit-8(CCK-8)assay and scratch assay,respectively.High-throughput RNA sequencing(RNA-Seq)was performed to identify differentially expressed genes(DEGs).Functional annotation and pathway enrichment analysis of the DEGs were performed using the Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.Results CCK-8 assay revealed that,after 72 h of culture,the absorbance value of the DeUFO-0 m group was 1.35 times and 1.27 times those of the those of the DeUFO-1 000 m and DeUFO-1 500 m groups,respectively(both P<0.000 1).After 96 h of culture,the absorbance value of the DeUFO-0 m group was 1.52 times and 1.41 times those of the DeUFO-1 000 m and DeUFO-1 500 m groups,respectively(both P<0.000 1).Colony formation assays revealed that the number of cell colonies in the DeUFO-0 m group was 1.59 times and 1.27 times those in the DeUFO-1 000 m group and DeUFO-1 500 m group,respectively(both P<0.001).The scratch assay revealed that the 36-hour wound healing rate of the DeUFO-0 m group was 2.22 times and 4.00 times those of the DeUFO-1 000 m group and DeUFO-1 500 m group,respectively(both P<0.000 1).Transwell assays revealed that the number of migrating cells in the DeUFO-0 m group was 2.08 times and 2.56 times those in the DeUFO-1 000 m group and DeUFO-1 500 m group,respectively(both P<0.000 1).Transcriptome sequencing analysis revealed consistent upregulation of CELF2,CELF4,CGB8,GRHL2,and DMRTA2 genes in the DeUFO-1 000 m and DeUFO-1 500 m groups.Pathway enrichment analysis indicated significant enrichment of extracellular matrix(ECM)remodeling-associated pathways and gene expression regulation pathways in the experimental groups(false discovery rate[FDR]<0.05).Conclusion The low background radiation environment in deep underground settings suppresses the proliferation and migration activities of NP69 cells by mediating ECM remodeling and post-transcriptional regulatory mechanisms through the regulation of target genes such as the CELF family.This study provides experimental evidence for establishing a dose-response relationship between environmental radiation and cellular effects.
6.Analysis of influencing factors on foot function recovery after distraction device-assisted repositioning of small incisions for Sanders type Ⅱ and Ⅲ calcaneal fractures
Bang-Yong ZONG ; Cai SONG ; Hao-Ran TIAN ; De-Yu WAN ; You-Fei FAN
Medical Journal of Chinese People's Liberation Army 2025;50(8):970-975
Objective To explore the influencing factors on foot function recovery after distraction device-assisted repositioning of small incisions treatment for Sanders Ⅱ and Ⅲ calcaneal fractures,and to provide guidance for timely clinical interventions.Methods A retrospective analysis was conducted on 80 patients with Sanders type Ⅱ and Ⅲ calcaneal fractures admitted to the People's Hospital of Bozhou from January 2021 to June 2023.Data were collected using a general information questionnaire,the hospital's electronic medical record system,the visual analog scale(VAS),the Marland foot function scale(MFS),the perceived social support scale(PSSS),and the perceived stress scale(PSS).The influencing factors of postoperative foot function recovery were analyzed using univariate factor analysis,multivariate linear regression,and structural equation modeling.Results The MFS scores of 80 patients at 6 months post-operation were significantly higher than preoperative scores(P<0.001).The rates of excellent,good,fair,and poor foot function at 6 months post-operation were 56.3%,31.3%,10.0%,and 2.5%,respectively.Univariate analysis revealed significant differences in MFS scores based on different ages,time to start full weight-bearing exercise,bone mineral density,surgical timing,body mass index(BMI),postoperative VAS score,PSSS score,PSS score,and the presence of postoperative peroneal muscle spasm and peroneal muscle tendon adhesion(P<0.05).Multivariate linear regression identified age,time to start full weight-bearing exercise,surgical timing,BMI,postoperative fibular muscle spasm,postoperative fibular muscle tendon adhesion,postoperative VAS score,PSSS score,and PSS score as significant factors affecting foot function recovery(P<0.05).Structural equation modeling indicated that age,time to start full weight-bearing exercise,bone density,operative timing,BMI,postoperative peroneal muscle spasm,postoperative peroneal tendon adhesion,and pain severity directly influenced postoperative foot functional recovery.Additionally,psychological stress not only directly affected postoperative foot functional recovery but also indirectly influenced it through the mediating effect of social support.Conclusions Foot function recovery after surgery for Sanders type Ⅱ and Ⅲ calcaneal fractures is influenced by multiple factors.Psychological stress not only directly affects the recovery of foot function after surgery,but also mitigates the harm to foot function through social support.
7.Specific extraction and analysis of synthesized proteins from mesenchymal stem cells transplanted into the ischemic heart
Wan-Er LU ; Ying DAI ; Mu-Han TANG ; Kang WEI ; Shu-Jia CHEN ; Huai HUANG ; Jing LIN ; Hao-Rong PENG ; Li-Xuan ZHOU ; Dun-Zheng HAN
Medical Journal of Chinese People's Liberation Army 2025;50(8):991-998
Objective To specifically extract and analyze nascent proteins synthesized by bone marrow mesenchymal stem cells(BMSCs)after transplantation into ischemic hearts using a technique employing mutant methionyl-tRNA synthetase(MetRSL247G)for nascent protein labeling,in order to explore the potential mechanisms of action in BMSCs post-transplantation.Methods Point mutation at position 274 of the MetRS gene in BMSCs was induced via lentiviral infection to enable azidonorleucine(ANL)-mediated labeling of nascent proteins in BMSCs.The labeling efficiency was verified by means of fluorescent non-canonical amino-acid tagging(FUNCAT).Thirty healthy female C57BL/6J mice(8-10 weeks old)were divided into control and experimental groups,with 15 mice in each group.The acute myocardial infarction model was constructed by ligating the left anterior descending coronary artery in experimental group,while control mice underwent only thoracotomy without coronary ligation.After modeling,both groups received intramyocardial injections of MetRSL247G-modified BMSCs(MetRSL247G-BMSCs)at 3 different sites in the peri-infarct ischemic region.Mice were intraperitoneally injected with ANL every 6 hours for 4 times on postoperative days 0,2,and 6(n=5 for each time point)respectively,euthanized 24 h after the last injection,and cardiac tissues were isolated.The newly synthesized and labeled proteins produced by BMSCs after transplantation into the myocardium of experimental and control groups were collected,using an enrichment technique for ANL-tagged proteins and liquid chromatography-tandem mass spectrometry(LC-MS)analysis.Gene ontology(GO)analysis,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,protein-protein interaction(PPI)analysis,and heatmap visualization analysis were performed to identify differentially expressed proteins at the 3 time points and screen key pathways and genes.Results Under fluorescence microscopy,the MetRSL247G lentivirus-infected BMSCs were observed to be labelled with mCherry signals,confirming the successful construction of the MetRSL247G-BMSCs cell line.Green fluorescent signals were detected only in nascent proteins in culture medium containing both MetRSL247G-BMSCs and ANL,validating the sensitivity and specificity of the labeling method.GO analysis revealed that differentially expressed proteins were primarily involved in basic cellular biological processes such as extracellular exosome formation,extracellular matrix organization,and focal adhesion.KEGG and PPI analyses indicated that the differential proteins were mainly involved in complement and coagulation cascade pathway,actin cytoskeleton regulation pathway,and apoptosis pathway.Heatmap analysis showed significantly upregulated expression of anti-apoptosis and cell adhesion-related factors in experimental group on day 1(P<0.05),upregulated anti-apoptotic factors,pro-apoptotic factors,and cell adhesion-related factors on day 3(P<0.05),and upregulated anti-apoptotic factors,cell differentiation-related factors,and cell adhesion-related factors on day 7(P<0.05)compared with control group.Expression of apoptosis-inducing factor 1 was significantly downregulated on days 1 and 7(P<0.05).On day 3,most differentially expressed proteins,including anti-apoptosis factors(Protein S100-A11,Clusterin,Gelsolin),pro-apoptosis factor(Cathepsin B),cell differentiation-related factor(Transgelin-2),and cell adhesion-related factors(Cofilin-1,Periostin,Fibronectin)were significantly upregulated(P<0.05).Conclusions The MetRSL247G mutation enables BMSCs to incorporate ANL and synthesize labeled proteins,confirming the feasibility of this nascent protein labeling technique.Nascent proteins of BMSCs in ischemic myocardium primarily contribute to extracellular exosome secretion and extracellular matrix organization.BMSCs may adapt to and respond to ischemic and hypoxic environments by influencing complement and coagulation cascades,activating inflammatory factors,regulating actin cytoskeleton structure,and modulating apoptosis,thereby maintaining the survival of BMSCs.
8.Exploring behavioral patterns and hippocampal neurogenesis in autism spectrum disorder mice
Xiao-Jie NIU ; Jiao LIU ; Xin-Wei ZHANG ; Ze-Tao WANG ; Ke-Qi YAN ; Qi-Yuan LIU ; Wan-Yun HAO ; Pei-Jun ZHANG
Acta Anatomica Sinica 2025;56(2):171-179
Objective To explore the behavioral patterns and hippocampal neurogenesis of CHD8+mice,and to provide behavioral and morphological basis for improving autism like behavior and neurogenesis.Methods Genotype of wild type(WT)and CHD8+/-mice was identified.Weight measurement was conducted on both male and female mice of the WT and CHD8+/-strains.Subsequently,a battery of behavioral tests was administered,which included three-chamber test,self-grooming test,nesting test,Y-maze spontaneous alternation test,food burial test,open-field test and light-dark transition test.Afterwards,the mice were administered 2%pentobarbital sodium(2 ml/kg)to induce anesthesia.Their brains were frozen with 4%paraformaldehyde,removed for photography and analysis to identify any alterations in brain size.Western blotting and immunofluorescent labeling were used to detect changes in the process of hippocampus neurogenesis.Results Western blotting analysis demonstrated a decrease in the amounts of chromodomain helicase DNA binding protein 8(CHD8)protein in both male and female mice with CHD8+genotype,as compared to WT mice.There were no notable disparities in body weight between male and female WT and CHD8+mice,as well as in brain size.The three-chamber social behavior test revealed that both male and female CHD8+/-mice had social deficiencies(P<0.05).During the open field test,there was no significant difference in the total distance moved by male and female WT and CHD8+/-mice.However,the amount of time spent in the central region was considerably lower in CHD8+/-mice compared to the WT mice(P<0.01).Furthermore,the light-dark transition test revealed that both male and female CHD8+/-mice spent considerably less time investigating the white box compared to the WT mice(P<0.05).Nevertheless,there were no notable alterations found in self-grooming,nesting,spontaneous alternation of Y-maze,and food burial experiments.In addition,Western blotting result demonstrated a significant drop in doublecortin(DCX)expression(P<0.001),and immunofluorescent staining revealed a notable reduction in the number of DCX+cells(P<0.01)in the hippocampus of CHD8+/-mice.Conclusion CHD8+/-mice exhibit social disorders and anxiety-like behaviors,with a decrease in the number of newly generated neurons in the hippocampus and neurogenesis disorders.
9.Mechanism of SOS1-IT1 promoting EZH2 expression in human endometrial cancer cells by regulating acetylation modification
Hong-Yang LIU ; Xue-Ling LOU ; Rong-Jing ZHANG ; Quan-Ling FENG ; Kai-Ge GUO ; Hao-Fan WANG ; Ying-Ying LI ; Jun-Hu WAN ; Lin-Dong ZHANG
Acta Anatomica Sinica 2025;56(4):444-451
Objective To explore the molecular mechanism by which SOS Ras/Rac guanine nucleotide exchange factor 1-intronic transcript 1(SOS1-IT1)affects enhancer of zeste homolog 2(EZH2)protein expression in endometrial cancer cells Ishikawa and RL95-2.Methods Lentiviral transfection of short hairpin RNA(shRNA)and overexpression plasmid were used in Ishikawa and RL95-2 cell lines to knock down and overexpress SOS1-IT1.The mechanism of EZH2 expression regulation was studied using Real-time PCR,Western blotting,and chromatin immunoprecipitation.Results The expression of SOS1-IT1 and EZH2 genes was positively correlated in endometrial cancer tissues.Knocking down SOS1-IT1 significantly reduces the expression of EZH2,inhibited the proliferation and migration of Ishikawa and RL95-2 cells,and could reduced the acetylation of histone H3 at position 27(H3K27)and the enrichment of CREB binding protein(CBP)in the EZH2 gene promoter region.Overexpression of SOS1-IT1 could increased the expression of EZH2 and enhance the acetylation of H3K27 and the enrichment of CBP.CBP could bind to SOS1-IT1 RNA,and this binding ability was weakened when CBP was knocked down.Conclusion SOS1-IT1 can promote the expression level of EZH2 in endometrial cancer cells Ishikawa and RL95-2 by regulating the acetylation modification level of the EZH2 gene promoter region,thereby affecting the proliferation and migration ability of endometrial cancer cells.
10.TRICHINELLA SPIRALIS NUCLEASE TS87 DEGRADES THE DNA BACKBONE OF MOUSE NEUTROPHILS EXTRACELLULAR TRAP
Ming-Ming ZHANG ; Yu-Wan HAO ; Yu-Li CHENG ; Jing-Jing HUANG ; Zhi-Hui JIA ; Xin-Ping ZHU
Acta Parasitologica et Medica Entomologica Sinica 2025;32(1):1-9,15
Objective This study aimed to investigate whether Trichinella spiralis Ts87 protein can facilitate immune evasion by degrading the mouse neutrophil extracellular traps(NETs).Methods First,we used bioinformatics tools to analyze the physicochemical properties of Ts87 and,through sequence homology alignment,confirmed its classification within the nuclease family.Molecular cloning and protein purification techniques were then employed to obtain high-purity Ts87 protein,and its nuclease activity was confirmed.Additionally,we compared the primary sequence of Ts87 with known active sites from human lysosomal DNase IIα and the structurally characterized Burkholderia thailandensis DNase II.This enabled us to predict potential active sites.Ts87 enzymatic mutants were generated using site-directed mutagenesis,and their functions were confirmed through enzymatic activity experiments.The extracellular nucleic acid content of mouse bone marrow neutrophils and the immunofluorescence staining of mouse NETs were assessed in vitro to verify whether the Ts87 protease mutants exhibited a decreased ability to degrade NETs.Finally,after immunizing mice with Ts87,calculated larvae burden and the degradation of NETs in vivo were observed by immunostaining the MPO and CitH3 expression in the intestinal NETs of the mice.Results High-purity Ts87 protein was successfully obtained and confirmed to possess nuclease activity,capable of degrading NETs in vitro.The Ts87 mutants exhibited reduced capacity in degrading NETs.In vivo experiments in mice demonstrated that the production of anti-Ts87 antibodies in immunized mice reduced the degradation of NETs,facilitating NET-mediated attack on the parasites and resulting in decreased larvae burden in the mice.Conclusions Trichinella spiralis can utilize Ts87 nuclease to evade capture by NETs,providing potential vaccine and drug targets for the prevention and treatment of trichinellosis.

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