CRFR1 activation protects against cytokine-induced β-cell death

Lykke Blaabjerg, Gitte L Christensen, Masahito Matsumoto, Talitha van der Meulen, Mark O Huising, Nils Billestrup, Wylie W Vale

Publikation: Bidrag til tidsskriftTidsskriftsartikelForskningpeer review

Abstract

During the development of diabetes β-cells are exposed to elevated concentrations of proinflammatory cytokines, TNFα and IL1β, which in vitro induce β-cell death. The class B G-protein-coupled receptors (GPCRs): corticotropin-releasing factor receptor 1 (CRFR1) and CRFR2 are expressed in pancreatic islets. As downstream signaling by other class B GPCRs can protect against cytokine-induced β-cell apoptosis, we evaluated the protective potential of CRFR activation in β-cells in a pro-inflammatory setting. CRFR1/CRFR2 ligands activated AKT and CRFR1 signaling and reduced apoptosis in human islets. In rat and mouse insulin-secreting cell lines (INS-1 and MIN6), CRFR1 agonists upregulated insulin receptor substrate 2 (IRS2) expression, increased AKT activation, counteracted the cytokine-mediated decrease in BAD phosphorylation, and inhibited apoptosis. The anti-apoptotic signaling was dependent on prolonged exposure to corticotropin-releasing factor family peptides and followed PKA-mediated IRS2 upregulation. This indicates that CRFR signaling counteracts proinflammatory cytokine-mediated apoptotic pathways through upregulation of survival signaling in β-cells. Interestingly, CRFR signaling also counteracted basal apoptosis in both cultured INS-1 cells and intact human islets.

OriginalsprogEngelsk
TidsskriftJournal of Molecular Endocrinology
Vol/bind53
Udgave nummer3
Sider (fra-til)417-27
Antal sider11
ISSN0952-5041
DOI
StatusUdgivet - dec. 2014
Udgivet eksterntJa

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