Bcl10 links saturated fat overnutrition with hepatocellular NF-kB activation and insulin resistance.
Excess serum free fatty acids (FFAs) are fundamental to the pathogenesis of insulin resistance. With high-fat feeding, FFAs activate NF-kB in target tissues, initiating negative crosstalk with insulin signaling. However, the mechanisms underlying FFA-dependent NF-kB activation remain unclear. Here, we demonstrate that the saturated FA, palmitate, requires Bcl10 for NF-kB activation in hepatocytes. Uptake of palmitate, metabolism to diacylglycerol, and subsequent activation of protein kinase C (PKC) appear to mechanistically link palmitate with Bcl10, known as a central component of a signaling complex that, along with CARMA3 and MALT1, activates NF-kB downstream of selected cell surface receptors. Consequently, Bcl10-deficient mice are protected from hepatic NF-kB activation and insulin resistance following brief high-fat diet, suggesting that Bcl10 plays a major role in the metabolic consequences of acute overnutrition. Surprisingly, while CARMA3 also participates in the palmitate response, MALT1 is completely dispensable, thereby revealing an apparent nonclassical role for Bcl10 in NF-kB signaling.
Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Matthew
M
Van Beek
Katherine I
KI
Oravecz-Wilson
Phillip C
PC
Delekta
Shufang
S
Gu
Xiangquan
X
Li
Xiaohong
X
Jin
Ingrid J
IJ
Apel
Katy S
KS
Konkle
Yongjia
Y
Feng
Daniel H
DH
Teitelbaum
Jürgen
J
Ruland
Linda M
LM
McAllister-Lucas
Peter C
PC
Lucas
D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000074018:B-Cell CLL-Lymphoma 10 Protein; D053468:CARD Signaling Adaptor Proteins / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D059305:Diet, High-Fat; D005227:Fatty Acids / Q000494:pharmacology*; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D023421:Models, Animal; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D016328:NF-kappa B / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism; D044343:Overnutrition / Q000378:metabolism; D010168:Palmitates / Q000494:pharmacology; D051381:Rats
D048868:Adaptor Proteins, Signal Transducing; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; C488088:Bcl10 protein, mouse; D053468:CARD Signaling Adaptor Proteins; C430880:CARD10 protein, human; C498975:Card10 protein, mouse; D005227:Fatty Acids; D016328:NF-kappa B; D009363:Neoplasm Proteins; D010168:Palmitates; D020169:Caspases; C400109:MALT1 protein, human; C498509:Malt1 protein, mouse; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein