The Protective Effect of HIF-1α in T Lymphocytes on Cardiac Damage in Diabetic Mice.

Diabetic cardiomyopathy (DCM) is associated with functional and structural pathological changes such as hypoxia and inflammation. Hypoxia-inducible factor-1α(HIF-1α) is a core transcription factor for restoring homeostasis in intracellular oxygen and has a crucial role in preventing the development of DCM. However, the effect of HIF-1α in T lymphocytes on DCM has not been reported. We established T lymphocyte-specific HIF-1α knockout homozygous mice that were injected with streptozotocin (STZ) for establishing diabetic models. Random blood glucose (RBG), body weight and the survival rate were detected. The cardiac pathological changes were evaluated by periodic acid-Schiff (PAS) staining, hematoxylin-eosin staining (HE) and Masson collagen staining. Cardiac function measurements were obtained by echocardiography. We observed the infiltration of T lymphocytes/CD3+ in the hearts by immunofluorescence stain. Also, we isolated splenic lymphocytes which would be in vitro cultured in the environment of high glucose and hypoxia. HIF-1α protein level of splenic lymphocytes was measured by Western blot. The results of this study indicate that the expression of HIF-1α in lymphocytes is activated in the complex environment of DCM consisting of hypoxia and high glucose. Also, HIF-1α in T cells plays a critical role in avoiding damage to the diabetic cardiac tissues.