HIF-1α Overexpression and Experimental Murine Atherosclerosis

BACKGROUND: Lymphocytes play an important role in the progression of atherosclerosis. Recently, hypoxia inducible factor-1 (HIF-1) was found to attenuate inflammation by regulating T cell activation and cytokine production. We studied the effects of overexpression of HIF-1alpha in ApoE knockout murine lymphocytes, on experimental atherosclerosis. METHODS AND RESULTS: ApoE-/- mice were submitted to intravenous hydrodynamic injection of empty plasmid or HIF-1alphaP564A (HIF-1alpha mutated stabilized construct). Robust expression of HIF-1alpha was evident in spleen cells of recipient animals. Increased expression of IL-10 as well as decreased expression of IFN-gamma was measured in splenocytes of HIF-1alpha-treated mice by RT-PCR. One week postinjection, antibody array analysis revealed a pattern consistent with a T helper 1 to T helper 2 shift. On sacrifice, assessment of aortic sinus lesions revealed a significant reduction in plaque size in HIF-1alpha injected mice. A reduced expression of IFN-gamma was evident in CD4+ spleen-derived lymphocytes and aortas of HIF-1alpha-injected mice. CONCLUSIONS: HIF-1alpha expression in mouse lymphocytes is associated with a reduced IFN-gamma expression and attenuation of experimental atherosclerosis.