c-Jun N-terminal kinase 2 deficiency protects against hypercholesterolemia-induced endothelial dysfunction and oxidative stress.

BACKGROUND: Hypercholesterolemia-induced endothelial dysfunction due to excessive production of reactive oxygen species is a major trigger of atherogenesis. The c-Jun-N-terminal kinases (JNKs) are activated by oxidative stress and play a key role in atherogenesis and inflammation. We investigated whether JNK2 deletion protects from hypercholesterolemia-induced endothelial dysfunction and oxidative stress. METHODS AND RESULTS: Male JNK2 knockout (JNK2(-/-)) and wild-type (WT) mice (8 weeks old) were fed either a high-cholesterol diet (HCD; 1.25% total cholesterol) or a normal diet for 14 weeks. Aortic lysates of WT mice fed a HCD showed an increase in JNK phosphorylation compared with WT mice fed a normal diet (P<0.05). Endothelium-dependent relaxations to acetylcholine were impaired in WT HCD mice (P<0.05 versus WT normal diet). In contrast, JNK2(-/-) HCD mice did not exhibit endothelial dysfunction (96+/-5% maximal relaxation in response to acetylcholine; P