Critical metabolic roles of β-cell M3 muscarinic acetylcholine receptors

Life Sci. 2012 Nov 27;91(21-22):986-91. doi: 10.1016/j.lfs.2012.04.010. Epub 2012 Apr 13.


Muscarinic acetylcholine (ACh) receptors (mAChRs; M(1)-M(5)) regulate the activity of an extraordinarily large number of important physiological processes. We and others previously demonstrated that pancreatic β-cells are endowed with M(3) mAChRs which are linked to G proteins of the G(q) family. The activation of these receptors by ACh or other muscarinic agonists leads to the augmentation of glucose-induced insulin release via multiple mechanisms. Interestingly, in humans, ACh acting on human β-cell mAChRs is released from adjacent α-cells which express both choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter (vAChT), indicative of the presence of a non-neuronal cholinergic system in human pancreatic islets. In order to shed light on the physiological roles of β-cell M(3) receptors, we recently generated and analyzed various mutant mouse models. Specifically, we carried out studies with mice which overexpressed M(3) receptors or mutant M(3) receptors in pancreatic β-cells or which selectively lacked M(3) receptors or M(3)-receptor-associated proteins in pancreatic β-cells. Our findings indicate that β-cell M(3) receptors play a key role in maintaining proper insulin release and whole body glucose homeostasis and that strategies aimed at enhancing signaling through β-cell M(3) receptors may prove useful to improve β-cell function for the treatment of type 2 diabetes (T2D).

Publication types

  • Research Support, N.I.H., Intramural
  • Review

MeSH terms

  • Animals
  • Diabetes Mellitus, Type 2 / genetics
  • Diabetes Mellitus, Type 2 / metabolism*
  • Gene Expression Regulation
  • Glucose / metabolism
  • Humans
  • Insulin / metabolism
  • Insulin-Secreting Cells / metabolism*
  • Mice
  • Mutation
  • RGS Proteins / metabolism
  • Receptor, Muscarinic M3 / genetics
  • Receptor, Muscarinic M3 / metabolism*


  • Insulin
  • RGS Proteins
  • Receptor, Muscarinic M3
  • RGS4 protein
  • Glucose