Biphasic regulation of glutamine consumption by WNT during osteoblast differentiation

Leyao Shen, Deepika Sharma, Yilin Yu, Fanxin Long, Courtney M. Karner

Research output: Contribution to journalArticlepeer-review

Abstract

Osteoblasts are the principal bone-forming cells. As such, osteoblasts have enhanced demand for amino acids to sustain high rates of matrix synthesis associated with bone formation. The precise systems utilized by osteoblasts to meet these synthetic demands are not well understood. WNT signaling is known to rapidly stimulate glutamine uptake during osteoblast differentiation. Using a cell biology approach, we identified two amino acid transporters, γ(+)LAT1 and ASCT2 (encoded by Slc7a7 and Slc1a5, respectively), as the primary transporters of glutamine in response to WNT. ASCT2 mediates the majority of glutamine uptake, whereas γ(+)-LAT1 mediates the rapid increase in glutamine uptake in response to WNT. Mechanistically, WNT signals through the canonical β-catenin (CTNNB1)-dependent pathway to rapidly induce Slc7a7 expression. Conversely, Slc1a5 expression is regulated by the transcription factor ATF4 downstream of the mTORC1 pathway. Targeting either Slc1a5 or Slc7a7 using shRNA reduced WNT-induced glutamine uptake and prevented osteoblast differentiation. Collectively, these data highlight the critical nature of glutamine transport for WNT-induced osteoblast differentiation.

Original languageEnglish (US)
Article number251645
JournalJournal of cell science
Volume134
Issue number1
DOIs
StatePublished - Jan 2021
Externally publishedYes

Keywords

  • Glutamine
  • Osteoblast
  • Slc1a5
  • Slc7a7
  • WNT
  • β-catenin

ASJC Scopus subject areas

  • Cell Biology

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