Effects of growth hormone-releasing hormone agonistic analog MR-409 on insulin-secreting cells under cyclopiazonic acid-induced endoplasmic reticulum stress

Mol Cell Endocrinol. 2021 Sep 15:535:111379. doi: 10.1016/j.mce.2021.111379. Epub 2021 Jul 9.

Abstract

The endoplasmic reticulum (ER) stress is one of the mechanisms related to decreased insulin secretion and beta cell death, contributing to the progress of type 2 diabetes mellitus (T2D). Thus, investigating agents that can influence this process would help prevent the development of T2D. Recently, the growth-hormone-releasing hormone (GHRH) action has been demonstrated in INS-1E cells, in which it increases cell proliferation and insulin secretion. As the effects of GHRH and its agonists have not been fully elucidated in the beta cell, we proposed to investigate them by evaluating the role of the GHRH agonist, MR-409, in cells under ER stress. Our results show that the agonist was unable to ameliorate or prevent ER stress. However, cells exposed to the agonist showed less oxidative stress and greater survival even under ER stress. The mechanisms by which GHRH agonist, MR-409, leads to these outcomes require further investigation.

Keywords: Beta cell; Endoplasmic reticulum stress; GHRH agonists; Oxidative stress; Type 2 diabetes; Unfolded protein response.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Cell Proliferation / drug effects
  • Cell Survival
  • Endoplasmic Reticulum Stress / drug effects*
  • Gene Expression Regulation / drug effects
  • Growth Hormone-Releasing Hormone / agonists
  • Growth Hormone-Releasing Hormone / metabolism
  • Indoles / adverse effects*
  • Insulin-Secreting Cells / cytology*
  • Insulin-Secreting Cells / drug effects
  • Insulin-Secreting Cells / metabolism
  • Oxidative Stress / drug effects
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Rats
  • Sermorelin / analogs & derivatives*
  • Sermorelin / pharmacology

Substances

  • GHRH protein, human
  • Indoles
  • N-Me-Tyr1,D-Ala2,Asn8,Arg29-NHCH3-JI-38
  • Proto-Oncogene Proteins c-bcl-2
  • Sermorelin
  • Growth Hormone-Releasing Hormone
  • cyclopiazonic acid