PUBLICATION

Interrupted Glucagon Signaling Reveals Hepatic α Cell Axis and Role for L-Glutamine in α Cell Proliferation

Authors
Dean, E.D., Li, M., Prasad, N., Wisniewski, S.N., Von Deylen, A., Spaeth, J., Maddison, L., Botros, A., Sedgeman, L.R., Bozadjieva, N., Ilkayeva, O., Coldren, A., Poffenberger, G., Shostak, A., Semich, M.C., Aamodt, K.I., Phillips, N., Yan, H., Bernal-Mizrachi, E., Corbin, J.D., Vickers, K.C., Levy, S.E., Dai, C., Newgard, C., Gu, W., Stein, R., Chen, W., Powers, A.C.
ID
ZDB-PUB-170608-2
Date
2017
Source
Cell Metabolism   25: 1362-1373.e5 (Journal)
Registered Authors
Chen, Wenbiao, Li, Mingyu
Keywords
Slc38a5, alpha cell, amino acid, amino acid transport, glucagon, glucagon receptor, glutamine, liver, pancreatic islet, proliferation
MeSH Terms
  • Amino Acid Transport Systems, Neutral/genetics
  • Amino Acid Transport Systems, Neutral/metabolism
  • Animals
  • Cell Proliferation*
  • Glucagon/genetics
  • Glucagon/metabolism*
  • Glutamine/genetics
  • Glutamine/metabolism*
  • Liver/metabolism*
  • Mice
  • Mice, Knockout
  • Signal Transduction*
  • Zebrafish
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
28591638 Full text @ Cell Metab.
Abstract
Decreasing glucagon action lowers the blood glucose and may be useful therapeutically for diabetes. However, interrupted glucagon signaling leads to α cell proliferation. To identify postulated hepatic-derived circulating factor(s) responsible for α cell proliferation, we used transcriptomics/proteomics/metabolomics in three models of interrupted glucagon signaling and found that proliferation of mouse, zebrafish, and human α cells was mTOR and FoxP transcription factor dependent. Changes in hepatic amino acid (AA) catabolism gene expression predicted the observed increase in circulating AAs. Mimicking these AA levels stimulated α cell proliferation in a newly developed in vitro assay with L-glutamine being a critical AA. α cell expression of the AA transporter Slc38a5 was markedly increased in mice with interrupted glucagon signaling and played a role in α cell proliferation. These results indicate a hepatic α islet cell axis where glucagon regulates serum AA availability and AAs, especially L-glutamine, regulate α cell proliferation and mass via mTOR-dependent nutrient sensing.
Genes / Markers
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Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
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Antibodies
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Mapping