[The significance of the changes in expressions of heat shock protein 70 and heme oxygenase-1 in the myocardium in patients died suddenly due to acute myocardial infarction].

OBJECTIVE

To investigate the changes and its clinical significance of the expressions of the mRNA and protein of heat shock protein 70 (HSP70) and heme oxygenase-1 (HO-1) genes in the myocardium of acute myocardial infarction (AMI) areas in patients who died suddenly due to AMI.

METHODS

Specimens of myocardial tissue at infarct site was obtained during autopsy from 18 patients who died suddenly due to AMI, and they were enlisted as study group, and that of myocardial tissue from 17 normal hearts of patients died rapidly after accidents were as control group. The levels of mRNA expression of HSP70 and HO-1 genes were measured in all the specimens by reverse transcription-polymerase chain reaction (RT-PCR) using cDNA samples, and the levels and locations of HSP70 and HO-1 protein expressions in myocardial cells of all specimens were examined by immunohistochemistry (IHC), and the pathological changes in the myocardial tissue were observed.

RESULTS

The expressions of HSP70 mRNA (0.841+/-0.058), HO-1 mRNA (0.918+/-0.161) and HSP70 protein (3 556.68+/-574.19), HO-1 protein (4 336.68+/-865.30) in the myocardium of the AMI areas in the study group were significantly higher than those in control group (the expressions of HSP70 mRNA: 0.105+/-0.034, HO-1 mRNA: 0.086+/-0.053, HSP70 protein: 289.21+/-68.51, HO-1 protein: 1 556.78+/-506.26, all P<0.01), and a weak expression of HSP70 and HO-1 protein was found in the cardiocytes of the AMI area in study group. In the control group, HSP70 protein expression was negative in the cardiocytes, and there was a weak expression of HO-1 protein in the cardiocytes. There was a significant positive correlation between the expressions of mRNA and protein of HSP70 and HO-1 genes at the cardiocytes of patients died suddenly of AMI in study group (r(1)=0.865, r(2)=0.816, both P<0.01).

CONCLUSION

HSP70 and HO-1 probably were both involved in the pathological and physiological processes of AMI, while HO-1 may express in cardiocytes, but it is more abundant in the cardiocytes in the AMI area.