Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism

SD Jordan, M Krüger, DM Willmes, N Redemann… - Nature cell …, 2011 - nature.com
SD Jordan, M Krüger, DM Willmes, N Redemann, FT Wunderlich, HS Brönneke, C Merkwirth
Nature cell biology, 2011nature.com
The contribution of altered post-transcriptional gene silencing to the development of insulin
resistance and type 2 diabetes mellitus so far remains elusive. Here, we demonstrate that
expression of microRNA (miR)-143 and 145 is upregulated in the liver of genetic and dietary
mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145,
impairs insulin-stimulated AKT activation and glucose homeostasis. Conversely, mice
deficient for the miR-143–145 cluster are protected from the development of obesity …
Abstract
The contribution of altered post-transcriptional gene silencing to the development of insulin resistance and type 2 diabetes mellitus so far remains elusive. Here, we demonstrate that expression of microRNA (miR)-143 and 145 is upregulated in the liver of genetic and dietary mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145, impairs insulin-stimulated AKT activation and glucose homeostasis. Conversely, mice deficient for the miR-143–145 cluster are protected from the development of obesity-associated insulin resistance. Quantitative-mass-spectrometry-based analysis of hepatic protein expression in miR-143-overexpressing mice revealed miR-143-dependent downregulation of oxysterol-binding-protein-related protein (ORP) 8. Reduced ORP8 expression in cultured liver cells impairs the ability of insulin to induce AKT activation, revealing an ORP8-dependent mechanism of AKT regulation. Our experiments provide direct evidence that dysregulated post-transcriptional gene silencing contributes to the development of obesity-induced insulin resistance, and characterize the miR-143–ORP8 pathway as a potential target for the treatment of obesity-associated diabetes.
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