Increased resistance against oxidant-induced injury in the rat vascular smooth muscle cells transfected with human heme oxygenase-1 gene / 生理学报

ABSTRACT

The heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme metabolism, has been recently defined as a novel stress-stimulated protein, since the intracellular expression of HO-1 in response to various stimuli as oxidation, ischemia and endotoxin injury has been proved to be able to protect the cells from damage. In this study, a retroviral vector containing human HO-1 gene was constructed and transfected to rat vascular smooth muscle cells (VSMCs). Using Southern and Northern blot analyses, the integration and mRNA expression of HO-1 gene in the transfected cells were confirmed. The profound protein expression of HO-1 as well as HO enzyme activity in the transfected cells increased by 1.8-fold and 2.0-fold respectively as compared with the non-transfected cells. It was found that the HO-1 transfected-VSMCs presented dominant resistance to toxicity produced by exposure to H2O2, as a significant protective effect of HO-1 marked by cell survival and LDH leakage was observed when 200, 400 and 600 micromol/L of H2O2 were used. The protection of HO-1 rapidly declined after the transfected-VSMCs were pretreated 24 h with an HO-1 specific inhibitor (ZnPP-IX). The results of this investigation suggest that the functional expression of HO-1 gene within VSMCs raises an alternative ability to protect the vascular cells against active oxygen injury.