Saeideh Jafarinejad-Farsangi1, Ali Farazmand2, Farhad Gharibdoost3, Elham Karimizadeh1, Farshid Noorbakhsh4, Habibeh Faridani3, Mahdi Mahmoudi3, Ahmad Reza Jamshidi5. 1. Department of Cell and Molecular Biology, University of Tehran, Tehran, Iran. 2. Department of Cell and Molecular Biology, University of Tehran, Tehran, Iran. afarazmand@khayam.ut.ac.ir. 3. Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. 4. Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 5. Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. jamshida@tums.ac.ir.
Abstract
BACKGROUND: Prolonged activation of dermal fibroblasts is the main cause of progressive fibrosis in systemic sclerosis (SSc). It seems that inhibition of apoptosis in SSc fibroblasts deregulates fibrosis. MicroRNA-21 (miR-21) is a pro-fibrotic factor with high expression in lesional areas of SSc skin and fibroblasts. METHODS: The effects of miR-21 on expression of Bcl-2 and Bax, two apoptotic genes, in dermal fibroblasts of SSc patients were evaluated using real-time polymerase chain reaction and Western blot analysis. Apoptotic cells were detected using flow cytometry and Hoechst 33258 staining assays. RESULTS: Overexpression of miR-21 using synthetic miR-21 RNA increased expression of Bcl-2, an inhibitor of apoptosis, and decreased the Bax : Bcl-2 expression ratio, a cell fate determinant, in SSc fibroblasts. Antisense inhibition of miR-21 induced a high rate of apoptosis in SSc fibroblasts. We propose that this may be associated with a decrease in Bcl-2 expression and a shift in the Bax : Bcl-2 ratio. CONCLUSIONS: Although further studies are necessary to determine the underlying apoptotic pathway, we propose that inhibition of miR-21 in dermal fibroblasts from lesional skin may be useful in harnessing progressive fibrosis in SSc.
BACKGROUND: Prolonged activation of dermal fibroblasts is the main cause of progressive fibrosis in systemic sclerosis (SSc). It seems that inhibition of apoptosis in SSc fibroblasts deregulates fibrosis. MicroRNA-21 (miR-21) is a pro-fibrotic factor with high expression in lesional areas of SSc skin and fibroblasts. METHODS: The effects of miR-21 on expression of Bcl-2 and Bax, two apoptotic genes, in dermal fibroblasts of SSc patients were evaluated using real-time polymerase chain reaction and Western blot analysis. Apoptotic cells were detected using flow cytometry and Hoechst 33258 staining assays. RESULTS: Overexpression of miR-21 using synthetic miR-21 RNA increased expression of Bcl-2, an inhibitor of apoptosis, and decreased the Bax : Bcl-2 expression ratio, a cell fate determinant, in SSc fibroblasts. Antisense inhibition of miR-21 induced a high rate of apoptosis in SSc fibroblasts. We propose that this may be associated with a decrease in Bcl-2 expression and a shift in the Bax : Bcl-2 ratio. CONCLUSIONS: Although further studies are necessary to determine the underlying apoptotic pathway, we propose that inhibition of miR-21 in dermal fibroblasts from lesional skin may be useful in harnessing progressive fibrosis in SSc.
Authors: Arjan van Caam; Madelon Vonk; Frank van den Hoogen; Peter van Lent; Peter van der Kraan Journal: Front Immunol Date: 2018-11-13 Impact factor: 7.561