5‐HT2 and 5‐HT2B antagonists attenuate pro‐fibrotic phenotype in human adult dermal fibroblasts by blocking TGF‐β1 induced non‐canonical signaling pathways including STAT3 : implications for fibrotic diseases like scleroderma. (12th September 2018)

• Record Type: Journal Article
• Authors: Chaturvedi, Saurabh; Misra, Durga Prasanna; Prasad, Narayan; Rastogi, Kailash; Singh, Harshit; Rai, Mohit Kumar; Agarwal, Vikas
• Is Part Of: International journal of rheumatic diseases. Volume 21:Number 12(2018)
• Page Start: 2128
• Page End: 2138
• Publication Date: 2018-09-12
• Subjects: Serotonin -- Serotonin antagonists -- Fibroblasts -- TGF‐β1 -- STAT3; Rheumatology -- Periodicals; Rheumatology -- Asia -- Periodicals; Rheumatology -- Pacific Area -- Periodicals; Rheumatic Diseases -- Periodicals; Connective Tissue Diseases -- Periodicals; Immune System Diseases -- Periodicals; 616.723
• DOI: 10.1111/1756-185X.13386
• Languages: English
• ISSNs: 1756-1841

Abstract

Abstract: Background: Release of 5‐hydroxytryptamine (5‐HT; serotonin) from activated platelets following microvascular injury leads to tissue fibrosis. 5‐HT strongly induces extracellular matrix synthesis in dermal fibroblasts in a transforming growth factor beta 1 (TGF‐β1)‐dependent manner. Aim: To evaluate anti‐fibrotic properties of inhibitors of 5‐HT2 and 5‐HT2B (terguride, SB204741) respectively in human adult dermal fibroblasts (HADF) derived from a patient with scleroderma. Methods: Anti‐fibrotic efficacy of 5‐HT2 and 5‐HT2B inhibitors was evaluated as per two strategies: HADF were incubated with 5‐HT (1 μM)/TGF‐β1 (10 ng/mL) for 1 hour followed by 5‐HT (1 μM)/TGF‐β1 (10 ng/mL) and terguride or SB204741 (1 μM, each) for 24 hours (post‐treatment strategy) and HADF were treated with terguride or SB204741 (1 μM, each) for 1 hour followed by 5‐HT (1 μM)/TGF‐β1 (10 ng/mL) for 24 hours (pre‐treatment strategy). Real time quantitative polymerase chain reaction for expression of pro‐fibrotic ( TGFΒ1, COL1A1, COL1A2, ACTA2, CTGF and FN1 ) and anti‐fibrotic genes ( MMP2 / TIMP1 ) was performed. Expression of type I collagen, alpha smooth muscle actin (α‐SMA), phosphorylation of Smad3, ERK1/2 and STAT3 was examined by immunoblotting. Results: Stimulation of HADF cells with 5‐HT/TGF‐β1 led to the increased expression of pro‐fibrotic genes which was significantly reduced by both terguride and SB204741. Expression of anti‐fibrotic genes was not affected upon incubation with the inhibitors. In 5‐HT‐stimulated HADF, treatment with terguride and SB204741 decreased type I collagen and α‐SMA. In 5‐HT/TGF‐β1 stimulated HADF, terguride and SB204741 treatment reduced ERK1/2 and STAT3 phosphorylation but did not influence Smad3 phosphorylation. Conclusion: Terguride and SB204741 reduce pro‐fibrotic potential of HADF cells and suppress TGF‐β1‐mediated non‐canonical pathways, ERK1/2 and STAT3 which have been implicated in the regulation of pro‐fibrotic genes and in the development of fibrosis. Taken together, our data suggest that 5‐HT inhibitors might reduce fibrosis via suppression of TGF‐beta1‐mediated non‐canonical signaling pathways. These observations have important therapeutic implications for fibrotic disorders like scleroderma.