GRK 2 level in peripheral blood lymphocytes of elderly patients with acute myocardial infarction.

OBJECTIVE: To investigate the G protein-coupled receptor kinase 2 (GRK 2) level in peripheral blood lymphocytes with cardiac function in elderly patients with acute myocardial infarction. METHODS: This study enrolled 40 patients with acute ST-segment elevation myocardial infarction (STEMI) and 40 patients with unstable angina. All patients were 65 years or older. Cardiac function was evaluated by echocardiography, and the GRK 2 level in peripheral blood lymphocytes was measured. Patients with STEMI were followed up for 2 years. RESULTS: The GRK 2 level in peripheral blood lymphocytes was significantly higher in patients with STEMI than in patients with unstable angina, and was negatively correlated with left ventricular ejection fraction, cardiac output, stroke volume, and left ventricular fractional shortening. The GRK 2 level was significantly elevated in some patients with acute STEMI and poor cardiac function. CONCLUSIONS: Increased GRK 2 level in patients with acute STEMI may contribute to poor myocardial systolic function and myocardial remodeling. Measurement of the GRK 2 level in peripheral blood lymphocytes may assist in the evaluation of cardiac function and myocardial remodeling in elderly patients with acute STEMI.

[Treatment of chronic heart failure by overexpressing sarcoplasmic reticulum calcium ATPase through gene therapy: an experiment with rats].

OBJECTIVE: To evaluate the value of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a) in the gene therapy of congestive heart failure. METHODS: (1) The abdominal aortas of 51 male SD rats were isolated and ligated so as to establish models of heart failure caused by contraction of abdominal aortas. 20 rats undergoing isolation of the abdominal aorta without ligation were used as controls. 18 approximately 20 days after the operation heart failure occurred, then the rats with contraction of abdominal aorta and heart failure were randomly divided into 3 groups: rAAV-SERCA2a group (recombinant adeno-associated virus containing SERCA2a cDNA, rAAV-SERCA2a, of the concentration of 2 x 10(11) v.g was injected via diaphragm into the pericardia cavity), heart failure control group (without trentment) and rAAV2-EGFP group (the control virus rAAV2-EGFP of the concentration of 2 x 10(11) v.g was injected via diaphragm into the pericardial cavity). 10 and 30 days after virus injection, a catheter was inserted through the jugular vein into the left ventricle to record the left ventricle systole pressure (LVSP), left ventricle end diastole pressure (LVEDP), left ventricle pressure maximum increase speed (+dp/dt), and left ventricle pressure maximum decrease speed (-dp/dt), and heart rate (HR). Then all the rats were killed and their hearts were taken out to examine the expression of the SERCA2a protein. (2) The left coronary arteries of 25 male SD rats were ligated so as to establish the models of cardiac infarction. 9 rats underwent isolation of the left coronary arteries without ligation and were used as controls. Four weeks after the operation thoracotomy was performed on the rats with heart failure caused by heart infarction, rAV-SERCA2a or rAV2-EGFP were injected into the myocardium, and dilute solution was injected to the control rats. 21 days later all the rats were performed hemodynamic exams. RESULTS: (1) Thirty days after the transfection the LVSP, +dp/dt, and -dp/dt of the rAAV-SERCA2a group were significantly higher than those of the rAAV2-EGFP group by 57% (94 mm Hg vs 147 mm Hg), 110% (5350 mm Hg/s vs 11 225 mm Hg/s), and 99.8% (4198 mm Hg/s vs 8390 mm Hg/s) respectively, meanwhile the LVEDP was significantly lower by 60% (22 mm Hg vs 9 mm Hg). These homodynamic parameters of the rAAV-SERCA2a group were not significantly different from those of the control group. Thirty days after transfection the expression of SERCA2a protein of the SERCA2a group was significantly higher than those of the control heart failure and rAAV2-EGFP groups. (2) Twenty-one days after the transfection, the LVSP, +dp/dt, and -dp/dt of the SERCA2a group were significantly higher than those of the control group by 28% (86 mm Hg vs 110 mm Hg), 41% (4272 mm Hg/s vs 6026 mm Hg/s), and 71% (2789 mm Hg/s vs 4756 mm Hg/s) respectively, and the LVEDP was significantly lower by 70% (3.89 mm Hg vs -5.34 mm Hg), however, these homodynamic parameters of the rAV-SERCA2a group were all worse compared with the control false operation group. CONCLUSION: The recombinant viruses, rAAV-SERCA2a and rAV-SERCA2a, effectively deliver the SERCA2a gene and improve the homodynamic state.

[Adeno-associated viral gene transfer of SERCA2a improves heart function in chronic congestive heart failure rats].

OBJECTIVE: To study the therapy effect of adeno-associated viral gene transfer of sarcoplasmic reticulum Ca(2+)-ATPase 2a (SERCA2a) on chronic congestive heart failure (HF) in 30 days, and the possible mechanism of the therapy effect. METHODS: The rats were divided into four groups: control group, HF group, Group HF + EGFP, and Group HF + SERCA2a. HF rats were obtained by creating descending aortic constriction. 0.9% sodium chloride solution, recombinant adeno-associated virus carrying enhanced green fluorescent protein gene (rAAV2.eGFP) and recombinant adeno-associated virus carrying SERCA2a gene (rAAV2.SERCA2a), were respectively delivered to pericardium of HF rats in different groups by intrapericardial injection with a trans-diaphragmatic approach. 30 days after gene transfer, hemodynamic parameters, SERCA2a protein expression and SERCA2a activity were analyzed. The proteome difference from rat hearts between Groups HF + SERCA2a and HF was detected by expression proteomics. Electrophoretic separation and quantitation of cardiac myosin heavy chain isoforms of hearts in different groups were performed at 30 days. RESULTS: At 30 days, left ventricular function improved significantly in HF rats infected with rAAV2.SERCA2a (LVSP 146.52 +/- 13.86 vs 97.91 +/- 12.13, LVEDP 7.88 +/- 2.88 vs 21.15 +/- 3.57, LV +dp/dt 11 206.16 +/- 1730.11 vs 5948.93 +/- 1283.43, LV -dp/dt -8249.54 +/- 1076.09 vs -4497.50 +/- 652.12; P < 0.05). The recovered cardiac function in Group HF + SERCA2a rats was comparable to control rats, and had lower LV-weight/Body-weight ratio (2.46 +/- 0.17 vs 2.71 +/- 0.24, P < 0.05). Overexpression of SERCA2a increased both the protein content (0.39 +/- 0.11 vs 1.11 +/- 0.18, P < 0.05) and activity (228.62 +/- 25.11 vs 82.55 +/- 14.13, P < 0.05) up to nonfailing levels. Expressions of some energy metabolic enzymes in hearts of Group HF + SERCA2a were much higher than those of HF group. They included creatine kinase-muscle, enolase beta, fructose-bisphosphate aldolase, mitochondrial H(+)-ATP synthase alpha subunit, electron transfer flavoprotein alpha-subunit, H(+)-transporting ATP synthase and heart fatty acid binding protein. Downregulation of alpha-MHC and upregulation of beta-MHC in failing hearts were observed. Gene transfer of SERCA2a could increase the expression of alpha-MHC [(74.48 +/- 3.74)% vs (53.57 +/- 2.30)%, P < 0.05], and decrease the expression of beta-MHC [(25.52 +/- 3.74)% vs (46.43 +/- 2.30)%, P < 0.05] in HF rats. The expression profiles of alpha-MHC and beta-MHC and the ratio of alpha-MHC/beta-MHC were similar to those in controls. CONCLUSIONS: Adeno-associated viral gene transfer of SERCA2a can enhance SERCA2a functions, maintain calcium homeostasis, improve cardiac energy metabolism, and normalize the expression of cardiac myosin heavy chain isoforms in HF rats. As a result, the ventricular systolic and diastolic functions can be improved significantly, and the hypertrophy of the heart may be reduced in clinic. Adeno-associated viral gene transfer of SERCA2a demonstrated good therapy effects on HF rats.