Effect of Cyclophilin "A" and Cyclosporine "A" on DSS-Induced IBD in Syndecan-1 Knock out Mice in Presence and Absence of Probiotics

Abstract

Introduction: Inflammatory Bowel Disease (IBD) is a chronic relapsing autoimmune inflammatory disease that results from the interplay between genetic and environmental factors. Cyclosporine “A” (CysA) has been described for its potency in IBD therapy, however it has been known for its serious adverse effects such as infections and nephrotoxicity. It forms a complex with intracellular cyclophilin (CypA), thus suppressing the activation of T-cells. On the other hand, extracellular cyclophilin “A”, has been known for its proinflammatory action through its binding to its cell surface receptor CD147.The signaling of Cyp-CD147 interaction remains unknown and requires further investigations. In addition, several studies have demonstrated the importance of syndecan-1 in controlling inflammation. They have shown the exacerbated status of inflammation in the colons of DSS-induced syndecan-1 deficient mice. Regarding probiotics, studies have illustrated their effective role in ameliorating intestinal inflammation in DSS-induced colitis models.

Hypothesis and aims: Based on the literature, we hypothesized first that cyclosporine “A” would reduce inflammation in sdc-1 deficient mice, second, the formation of cyclosporine-cyclophilin complex would further decrease the severity of IBD and third, probiotics would have a positive effect in ameliorating inflammation. Consequently, the aim of this study is to assess the effect of cyclosporine “A”, cyclophilin “A”, (cyclosporine+cyclophilin) complex and probiotics on the expression of proinflammatory markers (IL-6. CD147), pAKT signaling pathway activation and T-cells (CD3) in DSS-induced IBD in sdc-1deficient mice.

Materials and Methods: A total of 42 adult sdc-1 mice were used. IBD was induced by administering 1.5% of DSS, where each cycle of DSS consisted of 7 days of DSS followed by two weeks drinking water. Cyclosporine was intraperitoneally injected to mice, 200 ug every other day for 2 weeks. Cyclophilin was intraperitoneally injected as well, 25mg/kg/day for 1 week. Additionally, 108 mg/kg/day of probiotics (ProbioLife) were administered for 2 weeks. All the treatments started at day 7 of DSS induction. On the third week, six animals of each group were sacrificed and intestinal biopsies were frozen for protein extraction and fixed in 10% formalin for routine light microscopy. Histological scoring was calculated for each group. In addition, western blot determination of IL-6, CD147, CD3 and pAKT was performed.

Results: This study demonstrated that DSS-treated group showed a significant colon inflammation with more than 50% loss of goblet cells. However, both (DSS+Cyp) and (DSS+Cys) separately treated groups revealed a mild inflammation with an improvement in the mucosal architecture and a 25% loss of goblet cells. Whereas, the DSS+(Cyp-Cys) complex group exhibited a severe inflammation showing a detrimental effect on the colonic histology with a complete loss of goblet cells and severe inflammation in the intestinal mucosa and submucosa. The addition of probiotics to DSS+(Cyp-Cys) complex group displayed a slight reduction in inflammation where about 25% of goblet cells were restored. On the other hand, a notable reduction in inflammation occurred when mice were treated with DSS and probiotics in the absence of (Cyp-Cys) complex where about 75% of mucus secreting cells were restored. Furthermore, (IL-6, CD147, pAKT, and CD3) were assessed in each group showing similar results correlating with the histological analysis.

Conclusion: In light of these results, cyclosporine is a potent therapeutic agent for IBD in DSS-induced sdc-1 deficient mice and cyclophilin “A” might have a therapeutic role as well in ameliorating inflammation. However, the (Cyp-Cys) complex has a worsened effect on the colons of these mice. On the other hand, probiotics have worked more effectively in the absence of the complex in relieving inflammation. The mechanism by which syndecan-1 mice responded to the induced IBD remains to be elucidated.