CAJ | 학술논문

目的：明确Toll样受体4（TLR4）在百草枯（PQ）所致的心肌损伤是否具有作用，并分析其相关意义。方法雄性C57BL/6J野生（WT）小鼠和TLR4基因敲除（TLR4?ko）小鼠，分为4组：对照组（WT小鼠，n=6）、TLR4?ko组（TLR4?ko小鼠，n=6）、WT+PQ组（WT小鼠，n=30）、TLR4?ko+PQ组（TLR4?ko小鼠，n=30）。对照组和TLR4?ko组小鼠腹腔注射生理盐水，WT+PQ组和TLR4?ko+PQ组腹腔注射PQ（75 mg/kg）。染毒后2，4，8，16，24 h，分别选取6只WT+PQ组和TLR4?ko+PQ组小鼠处死，留取心肌组织标本用于组织病理学分析，WT+PQ组小鼠检测TLR4 mRNA表达。染毒2、8、24 h后，2组小鼠检测心肌组织中肿瘤坏死因子α（TNF?α）和白细胞介素1β（IL?1β）表达，Western blot检测WT+PQ组小鼠心肌中TLR4蛋白表达。对照组和TLR4?ko组小鼠在生理盐水处理后8 h，以同样的方法留取标本并进行相应检测。此外，在接受PQ或生理盐水处理后8 h，4组小鼠均使用2维超声M模式超声心动图仪评价心脏形态和心功能。结果 WT+PQ组小鼠在PQ致心肌损伤过程中，心肌组织出现了显著的病理损伤改变，心功能明显下降，心肌组织中TNF?α和IL?1β表达增加。与WT+PQ组小鼠比较，TLR4?ko组小鼠心肌功能下降程度和病理损伤程度减轻，相应的细胞因子TNF?α和IL?1β表达减少。结论 TLR4基因表达与PQ中毒后心脏功能下降和病理损伤之间存在密切联系，其作用机制涉及到下游信号细胞因子TNF?α和IL?1β。TLR4信号系统在PQ所致的心肌损伤中具有重要的作用。
목적：명학Toll양수체4（TLR4）재백초고（PQ）소치적심기손상시부구유작용，병분석기상관의의。방법웅성C57BL/6J야생（WT）소서화TLR4기인고제（TLR4?ko）소서，분위4조：대조조（WT소서，n=6）、TLR4?ko조（TLR4?ko소서，n=6）、WT+PQ조（WT소서，n=30）、TLR4?ko+PQ조（TLR4?ko소서，n=30）。대조조화TLR4?ko조소서복강주사생리염수，WT+PQ조화TLR4?ko+PQ조복강주사PQ（75 mg/kg）。염독후2，4，8，16，24 h，분별선취6지WT+PQ조화TLR4?ko+PQ조소서처사，류취심기조직표본용우조직병이학분석，WT+PQ조소서검측TLR4 mRNA표체。염독2、8、24 h후，2조소서검측심기조직중종류배사인자α（TNF?α）화백세포개소1β（IL?1β）표체，Western blot검측WT+PQ조소서심기중TLR4단백표체。대조조화TLR4?ko조소서재생리염수처리후8 h，이동양적방법류취표본병진행상응검측。차외，재접수PQ혹생리염수처리후8 h，4조소서균사용2유초성M모식초성심동도의평개심장형태화심공능。결과 WT+PQ조소서재PQ치심기손상과정중，심기조직출현료현저적병리손상개변，심공능명현하강，심기조직중TNF?α화IL?1β표체증가。여WT+PQ조소서비교，TLR4?ko조소서심기공능하강정도화병리손상정도감경，상응적세포인자TNF?α화IL?1β표체감소。결론 TLR4기인표체여PQ중독후심장공능하강화병리손상지간존재밀절련계，기작용궤제섭급도하유신호세포인자TNF?α화IL?1β。TLR4신호계통재PQ소치적심기손상중구유중요적작용。
Objective To clarify the role and significance of Toll?like receptor 4(TLR4)in myocardial damage following paraquat(PQ)poisoning in mice. Methods Male wild type C57BL/6J mice(WT)and male TLR4 deficient mice(TLR4?ko)were divided into four groups in the study:(1)control group(WT mice,n=6);(2)TLR4?ko group(TLR4?ko mice,n=6);(3)WT+PQ group(WT mice,n=30);(4)TLR4?ko+PQ group (TLR4?ko mice,n=30). The mice in group 1 and group 2 were injected intraperitoneally with saline;mice in group 3 and group 4 were injected in?traperitoneally with 75 mg/kg of PQ. At 2 h,4 h,8 h,16 h and 24 h after PQ administration,6 mice of WT+PQ group and TLR4?ko+PQ group were euthanized and the heart tissue specimens were harvested. All the specimens were analysed by histology,while the expression of TLR4 mRNA was only detected in samples of WT+PQ mice. The specimens at 2 h,8 h and 24 h after PQ administration were used for cytokines detection for WT+PQ group and TLR4?ko+PQ group;in addition,Western blot analysis was performed for WT+PQ group. At 8 h after treatment,control mice and TLR4?ko mice were euthanized by the same method. Mice were anesthetized for cardiac geometry and functional assessment using a 2?D guide M?mode echocardiography at 8 h following injection of either PQ or saline. Results During myocardial damage due to PQ exposure in WT+PQ mice,obvious histopathological changes were observed,as well as a noticeable decrease of heart function and increased expressions of TNF?αand IL?1β. Compared with the WT mice,TNF?αand IL?1βprotein levels,changes in heart function and histopathological changes were significantly attenuated following PQ exposure in myocardial damage in TLR4?ko mice. Conclusion The TLR4gene is involved with in heart functional injury and histopathological changes in myocardial damage following PQ poisoning in mice,which may through the regulation of TNF?αand IL?1βexpression. Our findings indi?cate that TLR4 plays an important role in mediating myocardial injury due to PQ.