Purchase this article with an account.
Ajay Sharma, David L. Phillips, Rajiv R. Mohan; A Possible Molecular Mechanism For Trichostatin-A-mediated Inhibition Of Corneal Fibrosis. Invest. Ophthalmol. Vis. Sci. 2011;52(14):2034.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
TG-Interacting Factor (TGIF) is a transcriptional repressor protein that binds to other transcriptional regulators such as HDAC, mSin3A and CtBP and interacts with Smads, suggesting that TGIF may act as a negative regulator of TGFβ signaling. We tested the hypothesis that (a) TGIF and its close homologue,TGIF2, are expressed in the cornea and (b) inhibition of TGFβ-driven fibrosis in the cornea by trichostatin-A (TSA) involves TGIF.
Fibrosis in human corneal fibroblasts (HSF) was produced by growing cultures in TGFβ (1ng/ml) under serum-free conditions. Cultures were treated with a vehicle, TGFβ1 (1ng/ml), TSA (250 or 500nM) or TGFβ1 (1ng/ml) + TSA (250 or 500nM) for various time points (30 min, 60 min, 2h and 24h) for studying the role of TGIF in TGFβ-driven inhibition of corneal fibrosis by TSA. Real-time PCR, immunocytochemistry and immunoblotting were used to analyze the levels of fibrosis markers [alpha smooth muscle actin (SMA) and fibronectin] and transcription factors (TGIF, TGIF2).
We demonstrated the expression of TGIF and TGIF2 transcription factors in human corneal fibroblasts. The expression of TGIF in HSF has not been previously reported. Our results show that TSA substantially enhanced TGIF and TGIF2 mRNA and protein (1.5-2 fold p<0.01) expression in HSF. The largest TGIF and TGIF2 expression was detected at 2h and 24h of TSA treatment. Fibrosis in HSF after TGFβ1 treatment was confirmed by increased mRNA and protein levels of fibrosis markers (SMA and fibronectin). TSA treatment significantly inhibited SMA and fibronectin mRNA and protein expression (60-75%±9; p<0.05-0.001) and showed substantial increase in TGIF and TGIF2 expression (2.5-3.0 fold) in cultures grown in presence of TGFβ1 under serum-free conditions. More experiments and quantification studies are underway.
The anti-fibrotic effects of TSA in the cornea are likely mediated, at least partly, through a mechanism dependent on TGIF signaling.
This PDF is available to Subscribers Only