Effects Of AnxB9 Gene Knockdown And Regular Exercise Training On Cardiac Function Of Aging Drosophila

1 ObjectiveUSA-Gal 4 systemwas used to regul ate the expression of Ca2+regulatory gene—AnxB9 in Drosophila melanogaster.Drosophila was used to carry out regul ar exerciseintervention in different age groups.The effects of AnxB9expression decrease on the cardiac function of Drosophila were studied by detecting the changes of the corresponding indexes of Drosophila cardiacfunction.At the sametime,we will explore the role of AnxB9 expressi on in the adaptive changes of exerci se heart and the anti aging function of exercise.2 Materials and methodsAnxB9 female flies(W[1118];P{GD11750}v27493)were hybridized with wild W1118 male fly and arm-Gal4 male fly,and F1 generation was taken.Then the F1 generation dividedinto quiet and control group(1-42d-AnxB9/w1118),quiet and knockdown group(1-42d-AnxB9/arm-Gal4),long training and control group(2-42d-AnxB9/w11118),ong trai ni ng and knockdown group(2-42d-AnxB9/arm-Gal 4),latetraining and control group(28-42d-AnxB9/w1118),late trai ni ng and knockdown group(28-42d-AnxB9/arm-Gal4),a total of 6 groups.Each group collected rare than 300 virginflies,in constant temperature(about 25?)and hum di ty(about 50%,simulated sunshine timeto give light irradiation.According to the program the fruit fly was used to carryout regular exercisetraining(To maintaina constant load,themovement speed of 0.20 r/s,a week of exercise for 5 days,dailyexercise 2.5h).After the end of the exercise program24h,wecarried out anatomical sampling of Drosophila.Detecti on:We will detect the expression level of AnxB9 inthe control group(AnxB9/W1118)and knock down group(AnxB9/arm-Gal 4)by qRT-PCR technique.At the age of 43 daysof Drosophi la(in the middle of the aging model),we randomlyselected a total of 40 flies in each group using M-modeechocardi ography to detect the cardiac function.At the sametime,we randomly selected 120 flies stat is tical life cycle.3 Results3.1 Detection of AnxB9 expressionThe results showed t hat compared with the AnxB9/W118 group,the relative expression of AnxB9 in the AnxB9/armGal4 groupdecreased by 29%,with a very significant difference(p<0.01).3.2 The result of M-mode cardiac functions in drosophilaTwo-way analysis of variance showed significant interaction effect(p<0.05)of HP,DH,FS,AI,Q;SI,FL shoved no i nteract i on(p>0.05),no nain effect(p>0.05).HP analysis results show that in the gene expression level-AnxB9/W1118 level,2-42d group was significantly higher than that of 1-42d group(p<0.05);in thegene expression level-AnxB9/armGal 4 level,there were no significant differences between the groups(p>0.05).I n the exercise level=1-42d,AnxB9/arm Gal 4 group was significantly higher than that of AnxB9/w1118 group(p<0.01);in the exercise level=2-426,AnxB9/arm-Ga/4group and AnxB9/w1118 group had no significant difference(p>0.05);the exercise level of level=28-42d,AnxB9/arm-Gal4 group was si gni f i cant I y hi gher than that in AnxB9/w1118 group(p<0.01).The results of DI analysis shoved that in the gene expression level-AnxB9/w1118 level,2-42d group was significantly hi gher than 1-42d group(p<0.01);the gene expressi on level=AnxB9/arm Gal4 1-42d group,2-42d group,28-42d group showed no signi ficant di ff erence(p>0.05).At the level of exercise level=1-42d and 28-42d,AnxB9/arm-Gal4 in group was significantly higher than that in group AnxB9/w1118(p<0.01).There was no significant di ff erence between AnxB9/arm-Gal4group and AnxB9/w1118group(p>0.05)at the level of exerciselevel=2-42d.AI analysis showed t hat in gene expressionlevel=AnxB9/w1118,1-42d group,2-42d group,28-42d group.There was no significant difference(p>0.05);gene expression level=AnxB9/arm Gal4,1-42d group and 28-42d group were significantly higher than that of group 2-42d(p<0.01).At the level of exercise level=1-42d or 2-42d,there was no significant difference between AnxB9/armGal4 group and AnxB9/w1118 group(p>0.05).The anxb9/armgal 4 group was significantly higher than that of group AnxB9/w1118(p<0.01)at the level of exercise.FS analysis shoved that in the gene expression level=AnxB9/w11118 level,2-42d group was significantly higher than that of 1-42d group(p<0.05);gene expressi on in the level-AnxB9/armGal 4 level,the di fferences were not significant(p>0.05).At t he level of exercise level=1-42d,the AnxB9/armGal4 group was significantly higher than that of AnxB9/w1118 group(p<0.01).There was no significant difference in exercise level=2-42d and 28-42d levels(p>0.05).In addition,SI,FL the interaction and the maineffect analysis showed no signif icant di fference between the groups(p>0.05).3.3 Analysis results of exercise ability testCI analysis showed that the AnxB9/arm Gal 4 group wassignificantly higher than AnxB9/W1118 group(p<0.01)atexercise level =1-42d.In the gene expression level =AnxB9/w1118level,2-42d group was signifi cantly higher than that of 1-42dgroup(p<0.01)and 28-42d group(p<0.01);at thelevel=AnxB9/arm Gal 4 level,there was no significantdifference between 1-42d group and 2-42d group,the two groupswere significantly higher than 28-42d group(p<0.01,p<0.01).3.4 The result of mortality of drosophilaIn exercise level =1-42d,2-42d and 28-42d inAnxB9/arm Gal4 group,the average survival period were higherthan that of group AnxB9/W1118(p<0.01).In geneexpression=AnxB9/arm Gal 4 or gene expression=AnxB9/W1118,the 2-42d group and 28-42d group average survival period weresignificantly higher than 1-42d group(p<0.01).Conpared withthe 1-42d-AnxB9/W1118 group,the other groups with time trendline position shifted to the right.Compared with 1-42d-AnxB9/W1118 group,the average survivaltime was 61.13 days,the average survival time of the1-42d-AnxB9/arm Gal 4 group was 70.15 days,and the percentageof life extension was up to 14.8%The 2-42d-AnxB9/W1118 group the average survival period of 69.74 days,the life prolonging rate reached 14.1%;2-42d-AnxB9/arm Gal 4 group the averagesurvival period of 73.75 days,the life prolonging rate reached20.6%the 28-42d-AnxB9/W1118 group t he average survival periodof 66.93 days,the life prolonging rate reached 9.5%;28-42d-AnxB9/arm-Gal 4 group the average survival period of73.90 days,the life prolonging rate reached 20.9%4 Conclusion(1)When the expression of AnxB9 was reduced or regularexercise training was carried out,it could significantlyincrease the cardiac cycle of the aging Drosophila.In theabsence of long-term exercise training,reducedAnxB9expression could improve the shortening fraction ofDrosophila.While the AnxB9 expression was not reduced,exercise coul dimprove the shortening fraction of Drosophila.(2)The results showed that the incidence of cardiac arrestand the symptoms of prolonged contraction increased when theAnxB9 expression decreased,while the rate of diastolicdysfunction was lower than that of the control group.Thedecrease of AnxB9 expression and the participation oflong-termregular exercise training can reduce the incidenceof arrhythmia.(3)Long term regular exercise training is helpful to improve the motor ability of Drosophila,and AnxB9 expression can also improve the motor ability of Drosophila.In the absence of AnxB9 expressi on,exercise training in the elderly may reduce the motor ability of Drosophila.(4)The results showed that the decrease of anxb9 gene expressi on or the participation of regul ar exercise training could prolong the life cycle of Drosophila.