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Obesity-Induced miR-455 Upregulation Promotes Adaptive Pancreatic β-cell Proliferation Through the CPEB1/CDKN1B Pathway

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posted on 14.01.2022, 13:13 by Ada AdminAda Admin, Qianxing Hu, Jinming Mu, Yuhong Liu, Yue Yang, Yue Liu, Yi Pan, Yanfeng Zhang, Ling Li, Dechen Liu, Jianqiu Chen, Fangfang Zhang, Liang Jin
Pancreatic β-cell adapt to compensate for increased metabolic demand during obesity. Although the microRNA (miRNA) pathway has an essential role in β-cell expansion, whether it is involved in adaptive proliferation is largely unknown. First, we report that EGR2 binding to the miR-455 promoter induced miR-455 upregulation in the pancreatic islets of obesity mouse models. Then, in vitro gain- or loss-of-function studies showed that miR-455 overexpression facilitated β-cell proliferation. Knockdown of miR-455 in ob/ob mice via pancreatic intraductal infusion prevented compensatory β-cell expansion. Mechanistically, our results revealed that increased miR-455 expression inhibits the expression of its target cytoplasmic polyadenylation element binding protein 1 (CPEB1), an mRNA binding protein that plays an important role in regulating insulin resistance and cell proliferation. Decreased CPEB1 expression inhibits elongation of the poly-A tail and the subsequent translation of Cdkn1b mRNA, reducing the CDKN1B expression level and finally promoting β-cell proliferation. Taken together, our results show that the miR-455/CPEB1/CDKN1B pathway contributes to adaptive proliferation of β-cells to meet metabolic demand during obesity.

Funding

This work was supported by National Natural Science Foundation of China (Grant No. 82070801, 82100858); This study was supported by the open fund of state key laboratory of Pharmaceutical Biotechnology, Nan-jing University, China (Grant no. KF-GN-202103). Supported by grants from the ‘111’ project (B16046); Supported by Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD); Supported by China Postdoctoral Science Foundation (2020M671661); Supported by Jiangsu Province Science Foundation for Youths (BK20200569); Supported by Jiangsu Province Research Founding for Postdoctoral (1412000016).

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