Vactosertib also abrogated TGF-β1-induced enhancement of extracellular matrix protein production and hydroxyproline content in PD fibroblasts <i>in vitro</i> by hindering the TGF-β1-induced Smad2/3 phosphorylation and nuclear translocation, and fibroblast-to-myofibroblast transdifferentiation.
Knockdown of HDAC7 in PD fibroblasts inhibited TGF-β1-induced nuclear shuttle of Smad2 and Smad3, transdifferentiation of fibroblasts into myofibroblasts, and abrogated TGF-β1-induced production of extracellular matrix protein.
The experiments showed that the protein and messenger RNA levels of α-smooth muscle actin in non-PD TA cells and PD plaque-derived cells were significantly higher in cells exposed to TGF-β1 than those not treated with TGF-β1.
We observed that Ad-HDAC2 shRNA decreased inflammatory cell infiltration, reduced transnuclear expression of phospho-Smad3 and regressed fibrotic plaque of the tunica albuginea in PD rats in vivo. siRNA-mediated silencing of HDAC2 significantly decreased the TGF-β1-induced transdifferentiation of fibroblasts into myofibroblasts and collagen production, and induced apoptosis by downregulating the expression of PARP1, and decreased the expression of cyclin D1 (a positive cell-cycle regulator) in primary cultured fibroblasts derived from human PD plaque in vitro.
Knockdown of HDAC2 in PD fibroblasts abrogated TGF-β1-induced extracellular matrix production by blocking TGF-β1-induced phosphorylation and nuclear translocation of Smad2 and Smad3, and by inhibiting TGF-β1-induced transdifferentiation of fibroblasts into myofibroblasts.
Subsequently, we identified that both mice models share a similar fibrotic gene expression profile in penile tissue (including procollagen I, TGF-beta(1), and plasminogen activator inhibitor-1 mRNA), suggesting that they share similar signaling pathways for progression to penile fibrosis.
The genes upregulated in PD only were decorin (an inhibitor of transforming growth factor-beta1 and a part of fibroblast replication/collagen synthesis) and early growth response protein.
When L-arginine (2.25 g/kg/day), pentoxifylline (10 mg/kg/day), or sildenafil (10 mg/kg/day) was given individually in the drinking water for 45 days to rats with a PD-like plaque induced by TGF beta1, each treatment resulted in a 80-95% reduction in both plaque size and in the collagen/fibroblast ratio, as determined by Masson trichrome staining.
When L-arginine (2.25 g/kg/day), pentoxifylline (10 mg/kg/day), or sildenafil (10 mg/kg/day) was given individually in the drinking water for 45 days to rats with a PD-like plaque induced by TGF beta1, each treatment resulted in a 80-95% reduction in both plaque size and in the collagen/fibroblast ratio, as determined by Masson trichrome staining.
Our results indicate that the homozygous wild type of the G915C single nucleotide polymorphism in the coding region of the TGF-beta1 gene, which was recently associated with elevated TGF-beta1 production and pulmonary fibrosis, may influence the predisposition to Peyronie's disease.