Withaferin-A reduces type I collagen expression in vitro and inhibits development of myocardial fibrosis in vivo.
Type I collagen is the most abundant protein in the human body. Its excessive synthesis results in fibrosis of various organs. Fibrosis is a major medical problem without an existing cure. Excessive synthesis of type I collagen in fibrosis is primarily due to stabilization of collagen mRNAs. We recently reported that intermediate filaments composed of vimentin regulate collagen synthesis by stabilizing collagen mRNAs. Vimentin is a primary target of Withaferin-A (WF-A). Therefore, we hypothesized that WF-A may reduce type I collagen production by disrupting vimentin filaments and decreasing the stability of collagen mRNAs. This study is to determine if WF-A exhibits anti-fibrotic properties in vitro and in vivo and to elucidate the molecular mechanisms of its action. In lung, skin and heart fibroblasts WF-A disrupted vimentin filaments at concentrations of 0.5-1.5 µM and reduced 3 fold the half-lives of collagen α1(I) and α2(I) mRNAs and protein expression. In addition, WF-A inhibited TGF-β1 induced phosphorylation of TGF-β1 receptor I, Smad3 phosphorylation and transcription of collagen genes. WF-A also inhibited in vitro activation of primary hepatic stellate cells and decreased their type I collagen expression. In mice, administration of 4 mg/kg WF-A daily for 2 weeks reduced isoproterenol-induced myocardial fibrosis by 50%. Our findings provide strong evidence that Withaferin-A could act as an anti-fibrotic compound against fibroproliferative diseases, including, but not limited to, cardiac interstitial fibrosis.
Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America.
Azariyas A
AA
Challa
Milica
M
Vukmirovic
John
J
Blackmon
Branko
B
Stefanovic
D000818:Animals; D002460:Cell Line; D024042:Collagen Type I / Q000235:genetics* / Q000378:metabolism; D004719:Endomyocardial Fibrosis / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D055786:Gene Knockout Techniques; D055166:Hepatic Stellate Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007545:Isoproterenol / Q000009:adverse effects; D008297:Male; D051379:Mice; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic; D059748:Proteolysis / Q000187:drug effects; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051900:Smad3 Protein / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D014746:Vimentin / Q000235:genetics / Q000378:metabolism; D054358:Withanolides / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity
D024042:Collagen Type I; D012333:RNA, Messenger; D051900:Smad3 Protein; D053773:Transforming Growth Factor beta1; D014746:Vimentin; D054358:Withanolides; D007545:Isoproterenol; C009684:withaferin A