Abstract 18673: JNK Inhibition Restores Endothelial Function in Type 2 Diabetes Mellitus

Abstract

Introduction: Diabetes mellitus type 2 is an increasingly public health problem and it is a major cause in the development of cardiovascular diseases. Endothelial dysfunction is a key mechanism that contributes to the pathogenesis of cardiovascular diseases and is a well-known feature of clinical diabetes. Prior studies have demonstrated an impaired nitric oxide bioavailability and a reduced endothelium-dependent vasodilation under diabetic conditions and in animal models, JNK activity has been widely described to be involved in systemic insulin resistance. Hypothesis: Our study aimed to evaluate the involvement of JNK in endothelial dysfunction, studying its potential role in altered eNOS activation and NO synthesis in diabetic patients. Methods: We measured endothelial function and JNK activity in freshly isolated endothelial cells from diabetic patients (n=38) and nondiabetic controls (n=40). Results: ECs from diabetic patients displayed impaired eNOS activation and reduced NO release after insulin and A23187 stimulation, consistent with the presence of endothelial dysfunction. JNK activation was higher in diabetic (**P=0.003), and was associated with lower flow-mediated dilation (r=-0.53, *P=0.02). In endothelial cells from diabetic patients, treatment with JNK chemical inhibitor (SP600125) restored eNOS activation and insulin response (***P<0.001). Nitric oxide bioactivity after A23187 stimuli with diabetes was also recovered in endothelial cells from patients with diabetes. Conclusions: In summary, our data suggest that JNK activation contributes to vascular insulin resistance and endothelial dysfunction in patients with type 2 diabetes and may represent a target in novel therapeutic opportunities.