| Research purposesExercise pre-adaptation is one of the research hotspots in sports medicine and life science,but the mechanism of exercise pre-adaptation to myocardial protection is not very clear.It has been found that the regulation of autophagy may be one of the mechanisms of exercise preconditioning myocardial protection.Autophagy is a conserved process of cell self-digestion and catabolism.JAK/STAT signaling pathway is involved in autophagy process,and the measurement of expression level of various key signaling molecules shows its involvement in autophagy regulation.Therefore,this study intends to use inhibitor technology to explore the autophagy regulation mechanism of exercise preconditioning myocardial protection effect from JAK/STAT signaling pathway,in order to provide basis for the study of preconditioning and autophagy mechanism.Research methodEight weeks old SD 80 male rats,Weight 260-300 g,Random cage feeding,After a week of adaptive feeding,Randomly divided into 8 groups,They were: exercise myocardial ischemia quiet control group(Q1),exercise myocardial ischemia non-inhibitory exercise group(F1),exercise myocardial ischemia AG490 inhibition exercise group(A1),exercise myocardial ischemia-reperfusion quiet control group(Q2),myocardial ischemia-reperfusion non-inhibitory exercise group(F2),myocardial ischemia-reperfusion AG490 inhibition exercise group(A2),myocardial ischemia-reperfusion exercise inhibition group(X2),each group of 10 rats.Sports training tools for rat runners,For eight weeks of exercise,Running 5 days a week,Take two days off.Exercise training model preparation refers to the Bedford of animal movement in accordance with the standard and Ding Shuzhe used by the rat platform increasing load model,After 24 h of training in week 8,To establish a model of exercise myocardial ischemia injury,myocardial ischemia reperfusion injury in vivo,After successful model building,femoral artery blood and myocardial tissue were taken,HE staining,pathological analysis,ELISA assay c Tn I、real-time fluorescence quantitative determination of myocardial tissue Beclin1 、 LC3-Ⅱ 、 LC3-Ⅰexpression,Western Blot determination of protein expression.Research result(1)The results of electrocardiogram showed that the model of exercise myocardial ischemia and ischemia-reperfusion injury was established successfully.In the exercise myocardial ischemia group,the elevation of J point in the quiet control group was significantly higher than that in the other three groups(P<0.01).Compared with the F1 group,the J point elevation was significantly different(P<0.J point elevation was significantly higher in the ischemia-reperfusion group than in the other three groups(P<0.05)in the quiet group compared with the F2 group;(2)HE staining showed that Q1 group compared with F1 group,The arrangement of cells is more disordered,the color is deeper,most of the cells rupture,F1 group compared with A1 group,X1 group,The cells are arranged neatly,and less staining;Q2 group compared to F2 group,The arrangement of cells is more disordered,Deep coloring,F2 group compared with A2 group,X2 group,The cells are arranged neatly,And less staining,Uniform size;(3)ELISA determination of cardiac troponin(c Tn I)in rats showed that compared with Q1,The content of c Tn I decreased significantly(P<0.01),A1、X1 were compared with F1(P<0.01),After eight weeks of training,After the inhibitor AG490、 sirolimus,myocardial injury level in rats was significantly higher than that in F1 group;F2 compared to Q2,The content of c Tn I decreased significantly(P less than 0.01),A2、X2 were compared with F2(P<0.01),After eight weeks of training,After the inhibitor AG490、 sirolimus,myocardial injury level in rats was significantly higher than that in F2 group;(4)Real-time fluorescence quantitative PCR detection of autophagy gene expression in rats showed that Q1 group compared with F1 group,Beclin1 gene expression level was higher(P<0.01),X1 group and A1 group compared with F1 group,Beclin1 gene expression decreased significantly(P <0.01,PP <0.05);Q2 group compared to F2 group,Beclin1 gene expression level was higher(P<0.01),X2 group and A2 group compared with F2 group,Beclin1 gene expression decreased significantly(P <0.05,PP <0.01).The expression ratio of LC3-Ⅱ/LC3-Ⅰgenes in Q1 group was significantly higher than that in F1 group,A significant difference in the ratio(P<0.01);F1 group compared with X1 group,A1 group,Gene expression levels were significantly different(P<0.01),The expression ratio of LC3-Ⅱ/LC3-Ⅰ genes in Q2 group was significantly higher than that in F2 group,A significant difference in the ratio(P<0.01);F2 group compared with X2 group,A2 group,Gene expression levels were significantly different(P<0.01).(5)The expression of JAK、STAT protein by Western blot assay showed that the F1 group compared with the Q1 group,The relative expression of JAK2 protein in F1 group was significantly lower than that in Q1 group,A1 group compared with F1 group,The relative expression of protein in A1 group was significantly different from that in F1 group(P<0.01).F2 group compared with Q2 group,The relative expression of JAK2 protein in F2 group was significantly lower than that in Q2 group,There were significant differences in protein expression between A2 group and F2 group(P<0.01);F1 group compared with Q1 group,The relative expression of STAT3 protein in F1 group was significantly lower than that in Q1 group,There was significant difference in protein expression between A1 group and F1 group(P<0.01).F2 group compared with Q2 group,The relative expression of STAT3 protein in F2 group was significantly lower than that in Q2 group,There was significant difference in protein expression between A2 group and F2 group(P<0.01).Analysis conclusionExercise preconditioning attenuates heart damage in acute exercise ischemia(physiologic ischemia)and myocardial ischemia-reperfusion(absolute ischemia),which increases myocardial autophagy to some extent.Exercise preconditioning activates JAK/STAT signaling pathways that regulate autophagy to produce myocardial protection. |
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