NF-κB-Inducing Kinase Rewires Metabolic Homeostasis and Promotes Diet-Induced Obesity

Abstract

AbstractObesity is a predominant risk factor for metabolic syndrome, which refers to a cluster of disorders that include diabetes, cardiovascular disease and fatty liver disease. Obesity and overnutrition are associated with aberrant immune and inflammatory responses resulting in increased local fat deposition, insulin resistance and systemic metabolic dysregulation. Here we show NF-κB-inducing kinase (NIK), a critical regulator of immunity and inflammation has local and systemic effects on metabolic processes. We demonstrate that NIK has NF-κB-independent and -dependent roles on adipose development and function. Independently of noncanonical NF- κB, NIK deficiency regulates mitochondrial spare respiratory capacity (SRC) and proton leak but establishes higher basal oxygen consumption and glycolytic capacity in preadipocytes and ex vivo adipose tissue. In addition, we demonstrate NIK promotes adipogenesis through its role in activation of the noncanonical NF-κB pathway. Strikingly, when challenged with a high fat diet, NIK deficient mice are protected against diet-induced obesity and insulin insensitivity. Overall, mice lacking NIK exhibit decreased overall fat mass and increased energy expenditure. Our results establish that, through its influences on adipose development, metabolic homeostasis and rewiring, NIK is a driver of pathologies associated with metabolic dysfunction.