The Lin28/let-7 axis regulates glucose metabolism
Hao Zhu, Ng Shyh-Chang, Ayellet V Segrè, Gen Shinoda, Samar P Shah, William S Einhorn, Ayumu Takeuchi, Jesse M Engreitz, John P Hagan, Michael G Kharas, Achia Urbach, James E Thornton, Robinson Triboulet, Richard I Gregory, DIAGRAM Consortium, MAGIC Investigators, David Altshuler, George Q Daley
Abstract
The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by inhibiting let-7 biogenesis. We have uncovered unexpected roles for the Lin28/let-7 pathway in regulating metabolism. When overexpressed in mice, both Lin28a and LIN28B promote an insulin-sensitized state that resists high-fat-diet induced diabetes. Conversely, muscle-specific loss of Lin28a or overexpression of let-7 results in insulin resistance and impaired glucose tolerance. These phenomena occur, in part, through the let-7-mediated repression of multiple components of the insulin-PI3K-mTOR pathway, including IGF1R, INSR, and IRS2. In addition, the mTOR inhibitor, rapamycin, abrogates Lin28a-mediated insulin sensitivity and enhanced glucose uptake. Moreover, let-7 targets are enriched for genes containing SNPs associated with type 2 diabetes and control of fasting glucose in human genome-wide association studies. These data establish the Lin28/let-7 pathway as a central regulator of mammalian glucose metabolism.
Conflict of interest statement
COMPETING FINANCIAL INTERESTS
The authors declare no competing financial interests.
Copyright © 2011 Elsevier Inc. All rights reserved.
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Source: PubMed