PUBLICATION

Hyperaminoacidemia induces pancreatic α cell proliferation via synergism between the mTORC1 and CaSR-Gq signaling pathways

Authors
Gong, Y., Yang, B., Zhang, D., Zhang, Y., Tang, Z., Yang, L., Coate, K.C., Yin, L., Covington, B.A., Patel, R.S., Siv, W.A., Sellick, K., Shou, M., Chang, W., Danielle Dean, E., Powers, A.C., Chen, W.
ID
ZDB-PUB-230117-12
Date
2023
Source
Nature communications   14: 235235 (Journal)
Registered Authors
Chen, Wenbiao
Keywords
none
MeSH Terms
  • Animals
  • Calcium/metabolism
  • Cell Proliferation
  • Female
  • Glucagon
  • Glucagon-Secreting Cells*/metabolism
  • Male
  • Mechanistic Target of Rapamycin Complex 1*/metabolism
  • Mice
  • Receptors, Calcium-Sensing*/metabolism
  • Signal Transduction*
  • Zebrafish/metabolism
PubMed
36646689 Full text @ Nat. Commun.
Abstract
Glucagon has emerged as a key regulator of extracellular amino acid (AA) homeostasis. Insufficient glucagon signaling results in hyperaminoacidemia, which drives adaptive proliferation of glucagon-producing α cells. Aside from mammalian target of rapamycin complex 1 (mTORC1), the role of other AA sensors in α cell proliferation has not been described. Here, using both genders of mouse islets and glucagon receptor (gcgr)-deficient zebrafish (Danio rerio), we show α cell proliferation requires activation of the extracellular signal-regulated protein kinase (ERK1/2) by the AA-sensitive calcium sensing receptor (CaSR). Inactivation of CaSR dampened α cell proliferation, which was rescued by re-expression of CaSR or activation of Gq, but not Gi, signaling in α cells. CaSR was also unexpectedly necessary for mTORC1 activation in α cells. Furthermore, coactivation of Gq and mTORC1 induced α cell proliferation independent of hyperaminoacidemia. These results reveal another AA-sensitive mediator and identify pathways necessary and sufficient for hyperaminoacidemia-induced α cell proliferation.
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