PLoS ONE (Jan 2020)

TGF-β-induced activation of conjunctival fibroblasts is modulated by FGF-2 and substratum stiffness.

  • Tomoyo Matsumura,
  • Tomokazu Fujimoto,
  • Akiko Futakuchi,
  • Yuji Takihara,
  • Fumika Watanabe-Kitamura,
  • Eri Takahashi,
  • Miyuki Inoue-Mochita,
  • Hidenobu Tanihara,
  • Toshihiro Inoue

DOI
https://doi.org/10.1371/journal.pone.0242626
Journal volume & issue
Vol. 15, no. 11
p. e0242626

Abstract

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PurposeThis study aimed to investigate the effects of substratum stiffness on the sensitivity of human conjunctival fibroblasts to transforming growth factor (TGF)-β, and to explore the molecular mechanism of action.MethodsHuman conjunctival fibroblasts were cultured on collagen-coated plastic or silicone plates. The stiffness of the silicone plates was 0.2 or 64 kPa. Cells were treated by 2.5 ng/mL TGF-β2 with or without fibroblast growth factor (FGF)-2 (0-100 ng/mL) for 24 h or 48 h. The protein expression levels were determined by Western blot analysis. Cell proliferation was assessed using the WST-8 assay.ResultsFGF-2 suppressed the TGF-β-induced expression of α-smooth muscle actin (SMA) and collagen type I (Col I), but not fibronectin (FN). Both FGF-2 and TGF-β2 increased cell proliferation without an additive effect. The induction of α-SMA by TGF-β2 was decreased on the soft substratum, without any change in the expression level or subcellular location of Yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ). FGF-2 suppressed TGF-β-induced α-SMA expression even on the soft substratum.ConclusionsFGF-2 treatment and a soft substratum suppressed TGF-β-induced transdifferentiation of conjunctival fibroblasts into myofibroblasts. FGF-2 attenuated the TGF-β-induced expression of α-SMA, even on a soft substratum.