CG9940基因过表达对幼龄和中龄果蝇心脏功能、攀爬能力运动应激敏感性的影响

The Effect of Overexpression of CG9940 mRNA on Exercise Stress Sensitivity of Cardiac Function and Climbing Ability in Young and Middle-age Drosophilas

目的:构建NAD合成酶基因CG9940全身过表达并进行运动干预,研究NAD合成酶基因CG9940过表达对幼龄和中龄果蝇心脏功能、攀爬能力运动应激敏感性的影响。方法:y[1]w[67c23]P{y[+m8]=Mae-UAS.6.11}CG9940[GG01267]雌性果蝇分别与W1 118雄性果蝇、arm-Gal4雄性果蝇杂交取F1代,分7d龄幼龄组和21 d龄中龄组,各年龄组分为对照组、运动组、过表达对照组和运动组,每组400只处女蝇。幼龄组饲养至第2 d龄开始训练,中龄组饲养至第16 d龄开始训练,连续训练5 d,分别于第7 d龄和21 d龄取材。qRT-PCR测定幼龄组CG9940基因mRNA表达量,M-mode心动图检测果蝇心脏心率和射血分数,测量攀爬指数。结果:析因结果表明CG9940基因过表达的构建对基因表达水平有影响(P<0.01),运动对CG9940基因表达水平无影响(P>0.05),过表达对照组CG9940 mRNA过表达率为155.2%,运动组为152.0%。在幼龄组中,与对照组相比,运动组、过表达对照组缩短分数增大(P<0.05),过表达运动组攀爬指数增大(P<0.05)、心率降低(P<0.05)、缩短分数升高(P<0.01),其余各组比较无显著性差异。中龄组中,与对照组相比,运动组心率降低(P<0.05)、缩短分数增大(P<0.05),过表达对照组心率降低(P<0.05)、缩短分数增大(P<0.05),过表达运动组攀爬指数增大(P<0.01)、心率降低(P<0.01)、缩短分数升高(P<0.01),其余各组比较无显著差异。结论:果蝇NAD合成酶基因过表达产生的NAD适应,能增强幼龄和中龄果蝇心脏泵血功能、心脏自律性、攀爬能力对运动训练的敏感性,产生明显运动效益,提示NAD合成酶基因表达改变可能会对运动敏感性产生影响;对于NAD合成酶基因表达上调个体,早期运动干预能更有效降低心脏疾病发生风险,增强心脏功能,提高运动能力。

Objective： To study the effect of overexpression of NAD synthase gene CG9940 mRNA on the exercise stress sensitivity of cardiac function and climbing ability in young and middle-age drosophila. Methods： For gene overexpression,y^[1]w^[67c23]P { y[＋ m8]= Mae-UAS. 6. 11 } CG9940^[GG01267]virgin females were crossed to arm-Gal4,and W1118 virgin females were crossed to armGal4 for control,F1 progeny virgin females of these two crosses were used as control（ C） group,exercise（ E） group,overexpression control（ OC） group and overexpression-exercise（ OE） group,as well as adult group,400 per group. The young group was reared to second days and trained,and the adult group was fed to sixteen days and trained,and then sampled at the 7thday and 21 stday after being trained 5 consecutive days. Determination of CG9940 gene expression of mRNA by qRT-PCR,the drosophilas＇ heart rate（ HR） and fraction shortening（ FS） were detected by M-mode,climbing index（ CI） for exercise capacity measurement.Results： the overexpression rate of mRNA in the OC group was155. 2%,and the overexpression rate in OE group was 152. 0%. In the young group,compared with the C group,the FS of E group and OC group was increased（ P〈0. 05）,the CI and FS of OE group were increased（ P〈0. 05 and P〈0. 01,respectively）,and the HR of OE group was decreased（ P〈0. 05）,while the other groups showed no significant difference. In the middle-aged group,compared to the C group,the HR of E group were decreased（ P〈0. 05）,the FS of E group were increased（ P〈0. 05）,the HR of OC group were decreased（ P〈0. 05）,and the FS of OC group were increased（ P〈0. 05）. The CI and FS of OE group were increased（ P〈0. 01）,and the HR of OE group were decreased（ P〈0. 01）.There was no significant difference in other groups. Conclusions：The overexpression of NAD synthetase gene mRNA can improve the physical training sensitivity of the climbing ability,automaticity of heart and heart pump function in young and middle-aged Drosophilas,which produces an obvious sports benefit. It suggests that NAD synthase gene polymorphism may produce effect on the susceptibility to exercise,and the early exercise intervention to increase the expression of NAD synthase gene was more likely to experience a lower risk of heart disease,and promote cardiac function and exercise ability.