RT Journal Article
SR Electronic
T1 Effects of Macitentan and Its Active Metabolite on Cultured Human Systemic Sclerosis and Control Skin Fibroblasts
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.141070
DO 10.3899/jrheum.141070
A1 Maurizio Cutolo
A1 Paola Montagna
A1 Renata Brizzolara
A1 Vanessa Smith
A1 Elisa Alessandri
A1 Barbara Villaggio
A1 Alberto Sulli
A1 Pietro Paolo  Tavilla
A1 Carmen Pizzorni
A1 Stefano Soldano
YR 2015
UL http://www.jrheum.org/content/early/2015/01/07/jrheum.141070.abstract
AB Objective To investigate the effects of the endothelin 1 (ET-1) receptor antagonists (ETRA) macitentan, its active metabolite ACT-132577, and bosentan on myofibroblast activation and extracellular matrix production induced by ET-1 in cultured systemic sclerosis (SSc) and control skin fibroblasts. Methods Fibroblasts were obtained from skin biopsies of 6 patients with SSc and 5 healthy subjects. Some cultured cells were untreated or treated with macitentan, ACT-132577, or bosentan alone (10 μM). Other cultured cells were treated with ET-1 alone (100 nM) or with ETRA, and after 1 h, also with ET-1. After 48 h of treatment, myofibroblast activation was investigated to evaluate the α-smooth muscle actin (α-SMA) expression by immunofluorescence; type I collagen (COL-1) and fibronectin (FN) were investigated by immunocytochemistry, Western blotting, and quantitative real-time PCR (qRT-PCR). Statistical analysis was performed by the nonparametric Mann-Whitney U test. Results In cultured SSc skin fibroblasts, only the treatment with macitentan significantly reduced the basal level of α-SMA expression (p = 0.03 vs untreated cells). Macitentan also significantly reduced the basal level of COL-1 synthesis, similarly to bosentan (p < 0.05 vs untreated cells). Macitentan or ACT-132577 antagonized the ability of ET-1 to further induce α-SMA expression (p = 0.03), COL-1, and FN synthesis (p = 0.03, p = 0.005); bosentan showed similar effects. These results obtained by immunofluorescence and immunocytochemistry were confirmed by Western blotting and qRT-PCR. The downregulatory effects exerted by ETRA were observed also in cultured human control skin fibroblasts. Conclusion Macitentan and ACT-132577 seem to downregulate in vitro the profibrotic myofibroblast phenotype induced by ET-1 in cultured human SSc skin fibroblasts.