Short-and middle-period therapeutic effects of recombinant adeno-associated viral gene transfer of sarcoplasmic reticulum Ca2+ ATPase on chronic congestive heart failure rats

Haipeng HUI; Xiaoying LI; Xiuhua LIU; Xiaochun LU; Wei YANG; Sheng SUN

ABSTRACT

BACKGROUND:

In chronic congestive heart failure (CHF),both protein expression and activity of sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA2a) are decreased, which results in abnormal regulation of calcium ion and systole and diastole dysfunction.

OBJECTIVE:

To observe the short-and middle-term therapeutic effects of adeno-associated viral gene transfer of SERCA2a in treatment of CHF in rats,and to investigate the possible mechanisms.

DESIGN:

Randomized-controlled design.

SETTING:

Department of Geriatric Cardiology and Department of Pathophysiology,General Hospital of Chinese PLA.

METHODS:

Male Sprague-Dawiey rats,were randomized into 4 groupssham-operation group,CHF group,CHF+ green fluorescent protein (GFP) group and CHF+SERCA2a group. Gene transfer 10 and 30 days two time points were set in each group.CHF rat models were established by coarctation of abdominal aorta.At postoperative 18 to 20 weeks,the successful rats in CHF group were intraperitoneally injected with 500 μL aseptic normal saline,and those in the CHF+ GFP group and CHF+ SERCA2a group were injected with the same dose of Adeno-associated viral gene with GFP and SERCA2a gene respectively.MAIN OUTCOME

MEASURES:

①At 10 and 30 days after gene transfer,hemodynamic parameters,the SERCA2a protein expression was analyzed by Western Blot,and SERCA2a activity was carded out by modified Jones method.②The difference of proteome of hearts was detected by expression proteomics in between CHF+ SERCA2a group and CHF group at 30 days.③Electrophoretic separation and quantitation of cardiac myosin heavy chain(MHC) isoforrns were done at 30 days.

RESULTS:

①In CHF group and CHF+GFP group, SERCA2a expression and activity were lower than those in sham-operation group.At 10 days after gene transfer.SERCA2a expression was increased by 80.7%and still lower than that of sham-operation group,and activity was also increased by 89.9%,but still lower than that of sham-operation group.And at 30 days,the SERCA2a protein expression and activity in the CHF+SERCA2a group reached to levels of sham-operation group. ②At day 10,LVSP and LV +dp/dtmax and LV-dp/dtmax were increased and LVEDP was decreased dramatically,but they still did not reach to the levels of sham-operation group.At day 30,the parameters were normalized back to control levels.There were no significant differences in each index between CHF+SERCA2a group and sham-operation group.③Overexpression of SERCA2a increased some energy metabolic enzymes of hearts at 30 days.④There were a downregulation of α-MHC and an upregulation of 3-MHC in failing hearts.Overexpression of SERCA2a increased the expression of α-MHC and decreased the expression of β-MHC to the levels of sham-operation group at 30 days.

CONCLUSION:

Adeno-associated viral gene transfer of SERCA2a can enhance SERCA2a functions, maintain calcium homeostasis,improve cardiac energy metabolism,and normalize the expression of MHC isoforms in CHF rats.As a result,the heart functions can be improved. So adeno-associated viral gene transfer of SERCA2a has good therapy effects on CHF rats in short and relatively long periods.