Prophylactic administration of all-trans retinoic acid alleviates inflammation in rats with collagen-induced arthritis

doi:10.3969/j.issn.1673-4254.2017.02.05

Abstract：Objective To investigate the effects of prophylactic administration of all-trans retinoic acid (ATRA) in relieving inflammation in a rat model of collagen-induced arthritis (CIA).Methods Female Wistar rats (6 to 8 weeks old) were randomly divided into normal control group,solvent control group,and prophylactic ATRA treatment (0.05,0.5,and 5 mg/kg) groups.All the rats except for those in normal control group were subjected to subcutaneous injection of type Ⅱ collagen and incomplete Freund adjuvant in the tails to induce CIA,followed by injection on the following day with saline,corn off or different doses of ATRA 3 times a week.The arthritis index (AI) scores,histological scores,serum levels of TNF-α,IL-17A,and IL-10,and expressions of proteases related with cartilage damage were evaluated.Results On the 15th day after the primary immumza tion,the AI scores increased significantly in all but the normal control groups;the scores increased progressively in all the 3 ATRA groups but remained lower than that in the solvent control group,which was stable over time.The rats in the 3 ATRA groups showed obvious pathologies in the knee and ankle joints,but the semi-quantitative scores of pathology damage showed no significance among them.Compared with those in solvent control group,the serum IL-17A and TNF-α levels decreased,serum IL-10 level increased,and the expressions of ADAMT-4 and MMP-3 proteins decreased significantly in the knees in the 3 ATRA groups.Conclusion ATRA can reduce the production of TNF-α and IL-17A and increase the production of IL-10 to alleviate the inflammation in rats with CIA.ATRA may delay the progression of RA by correcting the imbalance of Th1/Th2 and Th17/Treg.