Disruption of protein-tyrosine phosphatase 1B expression in the pancreas affects β-cell function

Siming Liu, Yannan Xi, Ahmed Bettaieb, Kosuke Matsuo, Izumi Matsuo, Rohit N. Kulkarni, Fawaz Haj

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and energy balance. However, the role of PTP1B in pancreatic endocrine function remains largely unknown. To investigate the metabolic role of pancreatic PTP1B,wegenerated mice with pancreas PTP1B deletion (panc-PTP1B KO). Mice were fed regular chow or a high-fat diet, and metabolic parameters, insulin secretion and glucose tolerance were determined. On regular chow, panc-PTP1B KO and control mice exhibited comparable glucose tolerance whereas aged panc-PTP1B KO exhibited mild glucose intolerance. Furthermore, high-fat feeding promoted earlier impairment of glucose tolerance and attenuated glucose-stimulated insulin secretion in panc-PTP1B KO mice. The secretory defect in glucose-stimulated insulin secretion was recapitulated in primary islets ex vivo, suggesting that the effects were likely cell-autonomous. At the molecular level, PTP1B deficiency in vivo enhanced basal and glucose-stimulated tyrosyl phosphorylation of EphA5 in islets. Consistently, PTP1B overexpression in the glucose-responsive MIN6 β-cell line attenuated EphA5 tyrosyl phosphorylation, and substrate trapping identified EphA5 as a PTP1B substrate. In summary, these studies identify a novel role forPTP1Bin pancreatic endocrine function. Copyright

Original languageEnglish (US)
Pages (from-to)3329-3338
Number of pages10
JournalEndocrinology
Volume155
Issue number9
DOIs
StatePublished - Sep 1 2014

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ASJC Scopus subject areas

  • Endocrinology

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