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Title: Activation of double-stranded RNA-dependent protein kinase inhibits proliferation of pancreatic β-cells

Highlights: •PKR can be activated by glucolipitoxicity and pro-inflammatory cytokines in β-cells. •Activated PKR inhibited β-cell proliferation by arresting cell cycle at G1 phase. •Activated PKR fully abrogated the pro-proliferative effects of IGF-I on β-cells. -- Abstract: Double-stranded RNA-dependent protein kinase (PKR) is revealed to participate in the development of insulin resistance in peripheral tissues in type 2 diabetes (T2DM). Meanwhile, PKR is also characterized as a critical regulator of cell proliferation. To date, no study has focused on the impact of PKR on the proliferation of pancreatic β-cells. Here, we adopted insulinoma cell lines and mice islet β-cells to investigate: (1) the effects of glucolipotoxicity and pro-inflammatory cytokines on PKR activation; (2) the effects of PKR on proliferation of pancreatic β-cells and its underlying mechanisms; (3) the actions of PKR on pro-proliferative effects of IGF-I and its underlying pathway. Our results provided the first evidence that PKR can be activated by glucolipitoxicity and pro-inflammatory cytokines in pancreatic β-cells, and activated PKR significantly inhibited cell proliferation by arresting cell cycle at G1 phase. Reductions in cyclin D1 and D2 as well as increases in p27 and p53 were associated with the anti-proliferative effects of PKR, and proteasome-dependent degradation took partmore » in the reduction of cyclin D1 and D2. Besides, PKR activation abrogated the pro-proliferative effects of IGF-I by activating JNK and disrupting IRS1/PI3K/Akt signaling pathway. These findings indicate that the anti-proliferative actions of PKR on pancreatic β-cells may contribute to the pathogenesis of T2DM.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [1] ;  [2] ;  [4] ;  [3] ;  [1] ;  [2]
  1. Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing (China)
  2. (China)
  3. Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Nanjing (China)
  4. Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing (China)
Publication Date:
OSTI Identifier:
22242275
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 443; Journal Issue: 3; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ANIMAL TISSUES; CELL CYCLE; CELL PROLIFERATION; INFLAMMATION; INSULIN; LYMPHOKINES; MICE; PANCREAS; PATHOGENESIS; RNA