Effects of sarco/endoplasmic reticulum Ca~(2+)-ATPase2a overexpression on the protein expression of L-type voltage dependent calcium channel a1c subunit in a rabbit model of acute atrial fibrillation

Objective To explore the effects of sarco/endoplasmic reticulum calcium ATPase2a(SERCA2a) overexpression on the protein expression of L-type voltage dependent calcium channel(LVDCCalc) subunit in rabbit models of atrial fibrillation(AF).Methods Forty-eight New Zealand rabbits were randomly divided into four groups(n=12),including control group,AF group,rAAV9+EGFP+AF group and rAAV9+SERCA2a+EGFP+AF group.rAAV9-EGFP and rAAV9-SERCA2a-EGFP in a dose of 1.0×1012 v.g/μL for each animal were injected into pericardium of the animals of rAAV9+EGFP+AF and rAAV9+ SERCA2a+EGFP(enhanced green fluorescent protein)+AF groups at thirty days before rapid atrial pacing.Thirty days after gene transfection,AF was induced by rapid atrial pacing(600 beats/min) for 24 hours in each animal of the AF group,rAAV9+EGFP+AF group and rAAV9+SERCA2a+EGFP+AF group.The animals of the control group were not paced.The animals were sacrificed to observe the expression of green fluorescent protein in the frozen sections of myocardium of rabbits in the rAAV9+ EGFP+AF group under an inverted fluorescence microscope,to assess the right atrial tissue morphology and detect the expressions of SERCA2a protein and LVDCCalc protein in the right atrial tissue in each group using HE staining and immunohistochemistry at 24 hours after pacing.ResultsCompared with the AF group and rAAV9+EGFP+AF group(P0.05),expressions of SERCA2a protein and LVDCCalc protein in the right atrium of rabbits of the rAAV9+SERCA2a+EGFP+AF group were significantly upregulated,but there was no significant difference in expressions of SERCA2a protein and LVDCCalc protein in the right atrium of rabbits among rAAV9+SERCA2a+EGFP+AF group,AF group and rAAV9+EGFP+AF group(P0.05).Conclusions The transgenic SERCA2a-overexpression in atrial tissue significantly reduces the down-regulation of the expression of LVDCCalc protein and reverse acute AF electrical remodeling in rabbit models of atrial fibrillation.