The MDM2-p53-pyruvate carboxylase signalling axis couples mitochondrial metabolism to glucose-stimulated insulin secretion in pancreatic β-cells

Xiaomu Li, Kenneth K.Y. Cheng, Zhuohao Liu, Jin Kui Yang, Baile Wang, Xue Jiang, Yawen Zhou, Philip Hallenborg, Ruby L.C. Hoo, Karen S.L. Lam, Yasuhiro Ikeda, Xin Gao, Aimin Xu

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

Mitochondrial metabolism is pivotal for glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells. However, little is known about the molecular machinery that controls the homeostasis of intermediary metabolites in mitochondria. Here we show that the activation of p53 in β-cells, by genetic deletion or pharmacological inhibition of its negative regulator MDM2, impairs GSIS, leading to glucose intolerance in mice. Mechanistically, p53 activation represses the expression of the mitochondrial enzyme pyruvate carboxylase (PC), resulting in diminished production of the TCA cycle intermediates oxaloacetate and NADPH, and impaired oxygen consumption. The defective GSIS and mitochondrial metabolism in MDM2-null islets can be rescued by restoring PC expression. Under diabetogenic conditions, MDM2 and p53 are upregulated, whereas PC is reduced in mouse β-cells. Pharmacological inhibition of p53 alleviates defective GSIS in diabetic islets by restoring PC expression. Thus, the MDM2-p53-PC signalling axis links mitochondrial metabolism to insulin secretion and glucose homeostasis, and could represent a therapeutic target in diabetes.

Original languageEnglish (US)
Article number11740
JournalNature communications
Volume7
DOIs
StatePublished - Jun 6 2016

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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    Li, X., Cheng, K. K. Y., Liu, Z., Yang, J. K., Wang, B., Jiang, X., Zhou, Y., Hallenborg, P., Hoo, R. L. C., Lam, K. S. L., Ikeda, Y., Gao, X., & Xu, A. (2016). The MDM2-p53-pyruvate carboxylase signalling axis couples mitochondrial metabolism to glucose-stimulated insulin secretion in pancreatic β-cells. Nature communications, 7, [11740]. https://doi.org/10.1038/ncomms11740