Changes in Expressions of HSP27, HSP70 and Soluble Glycoprotein in Heart Failure Rats Complicated with Pulmonary Edema and Correlations with Cardiopulmonary Functions Running title: Expressions of HSP27, HSP70 and Soluble Glycoprotein in Heart Failure

Abstract

Objective: The study aimed to investigate the changes in expressions of heat shock protein 27 (HSP27), HSP70 and soluble glycoprotein (SGP) in heart failure (HF) rats complicated with pulmonary edema, and explore their potential correlations with cardiopulmonary functions. Methods: The rat model of HF was established, and the rats were divided into HF model group (model group, n=15) and normal group (n=15). After successful modeling, MRI and ECG were applied to detect the cardiac function indexes of the rats. The myocardial function indexes were determined, the injury of myocardial tissues was observed via hematoxylin and eosin (HE) staining, and the content of myeloperoxidase (MPO), matrix metalloproteinase-9 (MMP-9) and tumor necrosis factor-alpha (TNF-a) in the blood was measured. The partial pressure of oxygen (Pa02) and oxygenation index (01) were observed, and the airway resistance and lung compliance were examined. Moreover, quantitative polymerase chain reaction (qPCR) and Western blotting assay were performed to detect the gene and protein expression levels of HSP27, HSP70 and SGP130. Results: The levels of serum creatine kinase (CK), creatine (Cr) and blood urea nitrogen (BUN) were increased markedly in model group (p<0.05). Model group had notably decreased fractional shortening (FS) and ejection fraction (EF) compared with normal group (p<0.05), while the opposite results of left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) were detected. In model group, the content of serum MPO, MMP-9 and TNF-a was raised remarkably (p<0.05), 01 and Pa02were reduced notably (p<0.05), the airway resistance was increased (p<0.05), and the lung compliance was decreased (p<0.05). Obviously elevated gene and protein expression levels of HSP27, HSP70 and SGP130 were detected in model group (p<0.05). Conclusion: The expressions of HSP27, HSP70 and SGP130 are increased in HF rats complicated with pulmonary edema, seriously affecting the cardiopulmonary functions of the rats.