Glucocorticoids reprogram ß-cell signaling to preserve insulin secretion

Nicholas Fine, Craig Doig, Yasir Elhassan, Nicholas Vierra, Piero Marchetti, Marco Bugliani, Rita Nano, Lorenzo Piemonti, Guy Rutter, David A Jacobson, Gareth Lavery, David Hodson

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)
226 Downloads (Pure)

Abstract

Excessive glucocorticoid exposure has been shown to be deleterious for pancreatic beta cell function and insulin release. However, glucocorticoids at physiological levels are essential for many homeostatic processes, including glycemic control. Here, we show that corticosterone and cortisol and their less active precursors, 11-dehydrocorticosterone (11- DHC) and cortisone, suppress voltage-dependent Ca2+ channel function and Ca2+ 6 fluxes in rodent as well as human beta cells. However, insulin secretion, maximal ATP/ADP responses to glucose and beta cell identity were all unaffected. Further examination revealed the upregulation of parallel amplifying cAMP signals, and an increase in the number of membrane-docked insulin secretory granules. Effects of 11-DHC could be prevented by lipotoxicity and were associated with paracrine regulation of glucocorticoid activity, since global deletion of 11β-hydroxysteroid dehydrogenase type 1 normalized Ca2+ and cAMP responses. Thus, we have identified an enzymatically-amplified feedback loop whereby glucocorticoids boost cAMP to maintain insulin secretion in the face of perturbed ionic signals. Failure of this protective mechanism may contribute to diabetes in states of glucocorticoid excess such as Cushing’s syndrome, which are associated with frank dyslipidemia.
Original languageEnglish
Pages (from-to)278-290
JournalDiabetes
Volume67
Issue number2
Early online date4 Dec 2017
DOIs
Publication statusPublished - Feb 2018

Keywords

  • 11β-hydroxysteroid dehydrogenase 18 type 1
  • cAMP
  • insulin
  • islet
  • incretin
  • steroid
  • glucocorticoid
  • adenylate cyclase

Fingerprint

Dive into the research topics of 'Glucocorticoids reprogram ß-cell signaling to preserve insulin secretion'. Together they form a unique fingerprint.

Cite this