Nuclear factor ?B?inducing kinase activation as a mechanism of pancreatic ? cell failure in obesity
The nuclear factor ?B (NF-?B) pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic ? cell dysfunction in the metabolic syndrome. Whereas canonical NF-?B signaling is well studied, there is little information on the divergent noncanonical NF-?B pathway in the context of pancreatic islet dysfunction. Here, we demonstrate that pharmacological activation of the noncanonical NF-?B?inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. We identify NIK as a critical negative regulator of ? cell function, as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of noncanonical NF-?B components p100 to p52, and accumulation of RelB. TNF and receptor activator of NF-?B ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive ? cell?intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the noncanonical NF-?B transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to ? cell failure. These studies reveal that NIK contributes a central mechanism for ? cell failure in diet-induced obesity.
|Authors||Malle, E.K.; Zammit, N.W.; Walters, S.N.; Koay, Y.C.; Wu, J.; Tan, B.M.; Villanueva, J.; Brink, R.; Loudovaris, T.; Cantley, J.; McAlpine, S.R.; Hesselson, D.; Grey, S.T.|
|Publisher Name||J EXP MED|
|Published Date||2015-06-29 00:00:00|