Paricalcitol inhibits the Wnt/beta-catenin signaling pathway and ameliorates experimentally induced arthritis

Abstract

Background/aim: The Wnt/β-catenin pathway has important biological activities, including the differentiation of cells and jointformations. The aim of our study was to determine the effect of paricalcitol on experimentally induced arthritis.Materials and methods: Type II collagen combined with Freund’s adjuvant was applied to induce arthritis in Wistar albino female rats.Paricalcitol (0.3 µg/kg daily) was subcutaneously injected starting 1 day after collagen applications (prophylactic group) or 1 day afterthe onset of arthritis (therapeutic group), until day 29.Results: The 29th day arthritis scores were lower compared to the 13th day scores in the paricalcitol groups (P < 0.05), while they werehigher in the arthritis group (P < 0.05). Marked cartilage-bone destruction and extensive perisynovial inflammation were detected inthe arthritis group. Decreased cartilage-bone destruction and perisynovial inflammation in the paws were observed in the paricalcitolgroups. The tissue mRNA levels of DKK1, Wnt5a, and axin-2 were higher in the arthritis group than in the control group. In theparicalcitol groups, mRNA expressions were lower than in the arthritis group.Conclusion: The present study shows that the Wnt/β-catenin signaling pathway is active in arthritis. Moreover, paricalcitol amelioratesarthritis via inhibiting the Wnt/β-catenin pathway. Paricalcitol and the Wnt/β-catenin pathway are candidates for research in humanrheumatoid arthritis.