Effects Of Intermittent Hypoxia Combined With Regular Exercise Mediated Akh Gene On Cardiac Function In Drosophila

1 ObjectiveIn this study,we used the UAS-Gal4 system to intervene in the Drosophila akh gene;Use hypoxia and exercise training devices to implement hypoxia intervention,exercise intervention and hypoxia combined exercise intervention on drosophila,and explore the effect of hypoxia combined exercise on the cardiac function（heart tube function）of fruit flies;Next,by knocking down the akh gene,we will study the effects of exercise,hypoxia and hypoxia combined exercise on the heart function of drosophila.To study the relationship between hypoxia,exercise and hypoxia combined exercise to promote cardiac function of drosophila and the akh gene,it provides a theoretical basis for hypoxia combined exercise to promote cardiac function.2 MethodsBy using the USA/GAL4 system,the Adipokinetic hormone regulatory gene UAS-RNAi strain Drosophila（akh）was crossed with the akh-gal4 strain and w¹¹¹⁸ to achieve the knock-down and normal expression of the Drosophila Adipokinetic hormone gene.Collect the F1 generation virgin flies of the above-mentioned hybrid two groups（the pupal does not exceed 8 hours）and randomly divided into: Quiet group（N）,Exercise group（NE）,Hypoxic group（NH）,Hypoxic combined exercise group（N-HE）,Gene Knockdown control group（Kd）,Gene knockdown exercise group（Kd-E）,Gene knockdown hypoxia group（Kd-H）,Gene knockdown hypoxia combined exercise group（Kd-HE）,a total of 8 groups,each group 400 only.The intervention group will intervene at the 8th day of age,and exercise intervention for 1.5 hours every day from 15:00 to 16:30;hypoxia intervention will be carried out during the period of 18:00 to 24:00;In the Hypoxic combined exercise group,exercise intervention first,rest for 1.5 hours,and then hypoxia intervention;all fruit flies were intervened for two weeks（intervention for 5 days,rest for 2 days,then intervention for 5 days）,and the samples were collected at a uniform time after the intervention.This experiment uses SPSS20.0 for data analysis,mainly using independent sample T test,single factor and two factor analysis of variance,non-parametric test methods,etc.to process and analyze the obtained results.3 Results3.1 Test results of qRT-PCR resultCompared with the N group,the relative expression of akh in the Kd group was down-regulated by 54%,indicating that the gene knockdown Drosophila model was successfully constructed;Compared with the N group,the N-E group had a relative overexpression of akh by 127%,The relative overexpression of Kd-E group was 63%,It suggesting that exercise can promote the expression of akh;Compared with the N group,the relative expression of akh in the N-H group was reduced by 31%,and the relative expression of akh in the Kd-H group was reduced by 75%;Point out: Hypoxia will inhibit the activity of akh.Compared with the N group,the relative expression of akh in the N-HE group was overexpressed by 68%,the relative expression of akh in the Kd-HE group was reduced by 60%;However,the Kd-HE group was overexpressed by15% relative to the Kd-H group.After hypoxia intervention,the relative expression of sima gene increased regardless of the normal gene expression of Drosophila or gene knockdown Drosophila,which is consistent with the relevant research results and the trend of related experimental results in this laboratory.3.2 Test results of TriglycerideThe systemic triglycerides of the Kd group were extremely significantly higher than that of the N group（P<0.01）;The systemic triglycerides of the NE group were extremely significantly lower than that of the N group（P<0.01）;At the same time,the Kd-E group had Systemic triglycerides were also extremely significantly lower than those in the Kd group（P<0.01）;The systemic triglycerides in the NH group were extremely significantly higher than those in the N group（P<0.01）;The systemic triglycerides in the N-HE group were extremely Significantly lower than the NH group（P<0.01）;3.3 Test results of Drosophila heart functionCompared with N,the Systolic Intervals of the Kd group showed a significant increase（P<0.01）.In the Systolic Diameter and the Diastolic Diameter,the Kd group was significantly larger than the N group（P<0.01）.Compared with the N group,the Kd group showed a significant increase in Arrhythmia Index（P<0.01）.Compared with the N group,the Kd group showed a significant increase in Fibrillation（P<0.05）.Compared with N group,the heart rate of N-E group decreased（P <0.05）;Compared with the KD group,the Systolic Intervals in the KD-E group was significantly shortened（P < 0.01）.Compared with N group,Fraction Shortening in N-E group was significantly increased（P < 0.01）.Compared with the Kd group,the Diastolic Diameter and Systolic Diameter of the Kd-E group were significantly decreased（P < 0.01）,but the Fraction Shortening was significantly increased（P < 0.01）.Compared with the N group,the Arrhythmia Index in the N-E group was significantly lower（P < 0.01）.At the same time,compared with the Kd group,the Arrhythmia Index of Kd-E was also significantly decreased（P< 0.01）.Compared with the Kd group,the Fibrillation was significantly decreased in the Kd-E group（P < 0.01）.The effect of hypoxia on the Heart Rhythm of drosophila is divided into two aspects: pure hypoxia can improve the heart function of drosophila,but the combination of genes needs further discussion.（1）In the drosophila with normal gene expression: Compared with the N group,the Heart Rate of the N-H group was significantly lower（P<0.05）;（2）In the drosophila with gene knockdown intervention: Compared with the Kd group,the heart rate of the drosophila in the Kd-H group was increased（P<0.01）,while the Diastolic Intervals and Systolic Intervals was decreased（P<0.01）.Compared with the Kd group,the Diastolic Diameter and Systolic Diameter of Drosophila in the Kd-H group were significantly decreased（P<0.01）.Hypoxic combined exercise can significantly reduce the Systolic Interval of the Drosophila heart（P<0.01）.Compared with the N group,the Diastolic and Systolic Diameters of the N-HE group decreased significantly（P<0.01）,but the Fraction Shortening was relatively significantly increased（P<0.01）;compared with the Kd group,the Diastolic Diameter of the Kd-HE group Both Systolic Diameter and Systolic Diameter decreased significantly（P<0.01）,and the Fraction Shortening increased significantly（P<0.01）.Compared with the N group,the Arrhythmia Index of N-HE significant decreased（P<0.01）.4 Conclusion4.1 Knockdown of akh gene can induce decreased heart function and abnormal lipid metabolism in Drosophila,mainly manifested in prolonged Systolic Interval,significantly increased Arrhythmia Index and Fibrillation,and increased triglyceride accumulation throughout the body.4.2 Exercise can improve the heart function of Drosophila and reduce the lipid accumulation of the whole body,and the improvement of the heart function of Drosophila by exercise is related to the akh gene.4.3 Hypoxia can promote the heart function of drosophila,but hypoxia cannot improve the heart function of drosophila by promoting the overexpression of akh gene.4.4 Hypoxia combined exercise can improve the heart function of Drosophila and reduce the body’s lipid accumulation,and it is related to the akh gene.