Effect And Mechanism Of Apelin-13on Neonatal Rat Cardiomyocytes Autophagy Induced By Glucose Deprivation

ObjectiveTo observe the effect of angiotensin1receptor-related apelin-13on glucosedeprivation (GD)-induced autophagy of injured cardiomyocytes and itsmechanism.MethodsCardiomyocytes from3days old Sprague Dawley suckling mice wereincubated in vitro. A cardiomyocyte injury model was induced by GD. Thecardiomyocytes were divided into five groups: normal control (Co), glucosedeprivation (GD), GD+Apelin-13, GD+Apelin-13treated with the Akt-specificinhibitor triciribine (GD+Apelin-13+Triciribine) and triciribine alone (Triciribine).After the experiment, The purity of primary myocardial cells were identified byimmunohistochemical method.Intracellular autophagosomes were observedunder transmission electron microscope. Expressions of autophagy-relatedmicrotubule light chain protein3(LC3) and signal pathway-related proteins(p-PI3K, p-Akt, and p-mTOR) were detected by Western blotting.Results1. The identification results of cardiomyocytes:10perspective, the averageratio of positive cells was90.80%, Cardiomyocytes high purity, which isbeneficial to the experiment.2. Observation of autophagosomes under TEM. The number ofautophagosomes in the GD group was significantly increased compared with in the Co group. The GD+Apelin-13group had markedly fewer autophagosomesthan the GD group. Conversely, the addition of triciribine, as in theGD+Apelin-13+Triciribine group, increased the number of autophagosomescompared with the GD+Apelin-13group. There was no significant differenceobserved between the Triciribine and Co groups3. Autophagy-related protein LC3expression. Compared with the Co group,the ratio of LC3-II/LC3-I in the GD group increased significantly (P<0.01).Conversely, the ratio was significantly decreased in the GD+Apelin-13groupcompared with the GD and GD+Apelin-13+Triciribine groups (both P<0.01). Asignificant difference was not observed between the Triciribine and Co groups4. Expression levels of PI3K/Akt/mTOR pathway-related proteins.Compared with the GD group, the p-PI3K、 p-Akt and p-mTOR expressionlevels in the GD+Apelin-13group were increased significantly (P<0.01), whichwere inhibited by the triciribine pretreatment except the p-PI3K (P<0.01).ConclusionGlucose deprivation induced suckling mice cardiomyocytes autophagy；Apelin-13is able to partially attenuate GD-induced autophagy by activatingthe components of the PI3K/Akt/mTOR signaling pathway.