Blockade of the Nuclear Factor-κB Pathway in the Endothelium Prevents Insulin Resistance and Prolongs Life Spans

Abstract

BACKGROUND: Nuclear factor-κB (NF-κB) signaling plays critical roles in physiological and pathological processes such as responses to inflammation and oxidative stress. METHODS AND RESULTS: To examine the role of endothelial NF-κB signaling in vivo, we generated transgenic mice expressing dominant-negative IκB under the Tie2 promoter/enhancer (E-DNIκB mice). These mice exhibited functional inhibition of NF-κB signaling specifically in endothelial cells. Although E-DNIκB mice displayed no overt phenotypic changes when young and lean, they were protected from the development of insulin resistance associated with obesity, whether diet- or genetics-induced. Obesity-induced macrophage infiltration into adipose tissue and plasma oxidative stress markers were decreased and blood flow and mitochondrial content in muscle and active-phase locomotor activity were increased in E-DNIκB mice. In addition to inhibition of obesity-related metabolic deteriorations, blockade of endothelial NF-κB signaling prevented age-related insulin resistance and vascular senescence and, notably, prolonged life span. These antiaging phenotypes were also associated with decreased oxidative stress markers, increased muscle blood flow, enhanced active-phase locomotor activity, and aortic upregulation of mitochondrial sirtuin-related proteins. CONCLUSIONS: The endothelium plays important roles in obesity- and age-related disorders through intracellular NF-κB signaling, thereby ultimately affecting life span. Endothelial NF-κB signaling is a potential target for treating the metabolic syndrome and for antiaging strategies.