Anomalous expression of heat shock protein 27 and glucose regulated protein 78 contributed to cardiac allograft vasculopathy

Abstract

Objective To observe the protein expression of heat shock protein 27 (HSP27) and glucose regulated protein 78 (GRP78) in rats transplanted hearts,and provide some clues to elucidate the pathogenesis of cardiac allograft vasculopathy (CAV).Methods The hearts were transplanted from Lewis to Sprague-Dawely rats as allograft (n =8) and from Lewis to Lewis rats as isograft (n =8) based on Ono' s model.The protein expression of HSP27 and GRP78 was detected by using immunohistochemistry [streptavid-inperoxidase (SP) method].Results The expression of HSP27 and GRP78 was stained uniformly in cardiac isografts,but that was anomalous in cardiac allografts,which showed higher expression on cardiac muscle (2.24 ± 0.36 vs.1.04 ± 0.10,P ＜ 0.01 ; 1.51 ± 0.12 vs.0.85 ± 0.30,P ＜ 0.05) and lower expression on blood vessels in biopsies with CAV (2.24 ±0.36 vs.0.25 ±0.08,P ＜0.01 ; 1.51 ±0.12 vs.0.16 ± 0.10,P ＜ 0.01).Conclusion The less expression of HSP27 and GRP78 on blood vessels decreased the defense to immunologic injury,which stimulated the over-proliferation of vascular smooth muscle cells to repair the vessels damage in heart allografts.Meanwhile,these protective reactions could incur the development of CAV in heart allografts. Key words: Cardiac allograft; Vasculopathy; Heat shock protein 27; Glucose regulated protein 78