TGF-β Coordinates Alanine Synthesis and Import for Myofibroblast Differentiation in Pulmonary Fibrosis.

ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease marked by aberrant fibroblast-to-myofibroblast differentiation, a process that requires metabolic reprogramming. We identify alanine as a critical metabolite that confers metabolic flexibility to support differentiation. TGF-β increases alanine by activating both its synthesis and import in normal and IPF lung fibroblasts. Alanine is synthesized primarily by GPT2, which is regulated by a glutamine-glutamate-α-ketoglutarate axis. Inhibiting GPT2 depletes alanine and suppresses TGF-β-induced expression of α-SMA and COL1A1, an effect reversed by alanine supplementation. We also identify SLC38A2 as a key transporter of both alanine and glutamine that is upregulated by TGF-β and alanine deprivation. Together, SLC38A2

SUBMITTER: Li F 

PROVIDER: S-EPMC12330655 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature