[HTML][HTML] The mTORC1/4E-BP1 axis represents a critical signaling node during fibrogenesis

HV Woodcock, JD Eley, D Guillotin, M Platé… - Nature …, 2019 - nature.com
HV Woodcock, JD Eley, D Guillotin, M Platé, CB Nanthakumar, M Martufi, S Peace…
Nature communications, 2019nature.com
Myofibroblasts are the key effector cells responsible for excessive extracellular matrix
deposition in multiple fibrotic conditions, including idiopathic pulmonary fibrosis (IPF). The
PI3K/Akt/mTOR axis has been implicated in fibrosis, with pan-PI3K/mTOR inhibition currently
under clinical evaluation in IPF. Here we demonstrate that rapamycin-insensitive mTORC1
signaling via 4E-BP1 is a critical pathway for TGF-β1 stimulated collagen synthesis in
human lung fibroblasts, whereas canonical PI3K/Akt signaling is not required. The …
Abstract
Myofibroblasts are the key effector cells responsible for excessive extracellular matrix deposition in multiple fibrotic conditions, including idiopathic pulmonary fibrosis (IPF). The PI3K/Akt/mTOR axis has been implicated in fibrosis, with pan-PI3K/mTOR inhibition currently under clinical evaluation in IPF. Here we demonstrate that rapamycin-insensitive mTORC1 signaling via 4E-BP1 is a critical pathway for TGF-β1 stimulated collagen synthesis in human lung fibroblasts, whereas canonical PI3K/Akt signaling is not required. The importance of mTORC1 signaling was confirmed by CRISPR-Cas9 gene editing in normal and IPF fibroblasts, as well as in lung cancer-associated fibroblasts, dermal fibroblasts and hepatic stellate cells. The inhibitory effect of ATP-competitive mTOR inhibition extended to other matrisome proteins implicated in the development of fibrosis and human disease relevance was demonstrated in live precision-cut IPF lung slices. Our data demonstrate that the mTORC1/4E-BP1 axis represents a critical signaling node during fibrogenesis with potential implications for the development of novel anti-fibrotic strategies.
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