The Study On Engineered Bone Marrow-Derived Mesenchymal Stem Cells For Murine Colitis Treatment

Mesenchymal stem cells (MSCs) are a prototypic adult stem cell with capacity for self-renewal and differentiation with a broad tissue distribution. It can be isolated from bone marrow, adipose tissue, umbilical cord blood, and peripheral blood and have the in-vitro differentiation capabilities to adipocyte, chondrocytes, osteoblasts, myocytes and neurons. For the past few years, MSCs have shown great promise as a biological therapeutic for a diverse range of clinical treatment. The reasons for this are many and include:ease of isolation and expansion in culture, low immunogenicity, immunomodulatory properties and homing behavior.The inflammatory bowel diseases (IBDs), represented mainly by ulcerative colitis(UC) and Crohn disease(Crohn’s), is a kind of intestinal immune disease characterized by repeated episodes and difficulty to cure. As a new cell-based therapy for IBD, exogenous MSCs can migrate to inflammatory sites in colon and release pleiotropic cytokines to promote intestinal immunomodulation. The reported clinical trials employing MSCs to treat IBD include two main approaches:systemic MSCs administration in luminal IBD and local MSCs administration in perianal fistulizing CD. However, the loss of some surface molecules in the process of ex-vivo expanding culture has an impact on the efficiency of MSCs homing, which reduces the number of cells migrating to target tissues and shows minimal persistence for treatment.In order to enhance homing capacity of MSCs and improve the therapeutic efficiency of MSCs therapy for IBD, we constructed engineered BM-MSCs and study the therapeutic efficacy of murine colitis. We first isolated MSCs from murine bone marrow and constructed engineered BM-MSCs by transfecting with lentivirus carrying CX3CR1 and IL-25 genes. Then, we identified the proliferation and phenotype of engineered BM-MSCs and measured the in-vitro migration ability using Transwell method. Afterward, we systematically administrated engineered BM-MSCs into DSS-induced colitis model and demonstrated the migration to intestinal inflammatory sites by immunofluorescent staining. Finally, we used a series of experiments, including colon photography, body weight measurement, disease activity index, colon pathology, MPO and inflammatory cytokines expression test, to demonstrate that engineered BM-MSCs can improve the therapeutic efficiency in murine colitis treatment.The significance of this study lies in the successful construction of engineered BM-MSCs specifically expressing CX3CR1 and IL-25. The homing efficiency of BM-MSCs has been improved by CX3CL1-CX3CR1 axis which leads to more cells migrating to intestinal inflammatory sites. Moreover, the immunosuppression function of IL-25 in IBD has also been realized. Thus, we provide a new idea in MSCs therapy for IBD.