Effects Of Transforming Growth Factor Beta 1 Preconditioning On Hypoxia/Reoxgenation-induced Injury Of Cardiomyocytes By Regulating The Protein Expression Of Hypoxia Inducible Factor-1 Alpha

Objective: To investigate transforming growth factor beta 1(TGF-β1)regulate the protein expression level of hypoxia inducible factor-1 alpha(HIF-1α) whether can effect the cardiomyocytes hypoxia/reoxgenation-induced. Methods: H9c2 cardiomyocytes were exposed to hypoxia/reoxgenation-induced injury and hypoxic preconditioning. The H9c2 cardiomyocytes were randomly divided into five groups:Control group(Control), hypoxia/reoxgenation group(H/R), hypoxic preconditioning(HPC), TGF-β1 preconditioning group(TGF-β1-Pre), TGF-β1 inhibitor group(group SB431542). The LDH activity, HIF-1α protein content and cardiomyocytes apoptosis rate were measured at the end of the experiment. Results: The LDH activity of Control group, H/R group, HPC group, TGF-β1-Pre group, SB431542 group were(201.2±48.9)U/L,(936.6±93.7)U/L,(727.0±75.9)U/L,(747.3±63.1)U/L,(957.3±55.3)U/L, respectively. The cell apoptosis rate of group Control group, H/R group, HPC group, TGF-β1-Pre group, SB431542 group were(25.5±3.2)%,(71.8±5.5)%,(42.8±6.1)%,(54.1±4.1)%,(82.8±9.7)%, respectively. HPC group, TGF-β1-Pre group reduced the LDH activity and cardiomyocytes apoptosis rate compared with H/R group, and increased the HIF-1α protein content, which had significantly statistical differences. Compared with HPC group, TGF-β1-Pre group had no significantly statistical difference. Conclusion: No matter in normoxia or hypoxia, TGF-β1 can increase the HIF-1α protein expression level, and play a role of antiapoptotic on hypoxia/reoxgenation-induced injury of cardiomyocytes, which associated with the protein expression level of HIF-1α.