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- Title
Overactivation of NF-κB impairs insulin sensitivity and mediates palmitate-induced insulin resistance in C2C12 skeletal muscle cells.
- Authors
Jingwen Zhang; Wen Wu; Dongfeng Li; Ying Guo; Helin Ding
- Abstract
Abstract  Lipid-induced insulin resistance is associated with inflammatory state in epidemiological studies. However, it is still unclear whether the activation of NF-κB, a pivotal transcription factor of inflammation, plays a crucial role in mediating skeletal muscle insulin resistance. This study addressed what was the role of NF-κB in lipid-induced insulin resistance and whether NF-κB activation was sufficient to cause insulin resistance in C2C12 myotubes. A 16 h exposure of myotubes to palmitate reduced net insulin-stimulated glucose uptake by 48%, GLUT4 translocation by 52%, Akt phosphorylation by 54%, induced a 1.8-fold increase in insulin-stimulated insulin receptor substrate (IRS) phosphorylation, and doubled NF-κB activation. Myotubes transfected with NF-κB p65 siRNA for 24 h and followed by a treatment with palmitate for 16 h efficiently blocked NF-κB activation, and prevented the detrimental effects of palmitate on the metabolic actions of insulin. Transfection of myotubes with I-κBα siRNA for 24 h also led to a twofold induction of NF-κB activation, and reduced net insulin-stimulated glucose uptake by 30%, GLUT4 translocation by 35%, Akt phosphorylation by 31%, induced a 0.7-fold increase in insulin-stimulated IRS phosphorylation. These findings suggest that NF-κB overexpression per se is sufficient to impair insulin sensitivity and palmitate-induced insulin resistance is mediated by NF-κB in skeletal muscle cells.
- Subjects
NF-kappa B; INSULIN resistance; STRIATED muscle; PALMITIC acid; INSULIN receptors; PHOSPHORYLATION; NON-coding RNA; MUSCLE cells
- Publication
Endocrine (1355008X), 2010, Vol 37, Issue 1, p157
- ISSN
1355-008X
- Publication type
Article
- DOI
10.1007/s12020-009-9283-y