Berberine pretreatment enhances the homing and anti-inflammatory efficacy of dental pulp mesenchymal stem cells in TNBS-induced inflammatory bowel disease via activating the CXCR4/SDF-1 signaling pathway.

OBJECTIVE: Inflammatory bowel disease (IBD) is a chronic intestinal disorder characterized by immune dysregulation and persistent inflammation. Mesenchymal stem cell (MSC) therapy shows promise but is limited by low homing efficiency. This study aimed to investigate whether berberine (BBR) pretreatment enhances the homing capacity and therapeutic efficacy of dental pulp MSCs (DP-MSCs) in IBD, and to clarify the role of the CXCR4/SDF-1 signaling pathway in immunomodulation.

METHODS: Human dental pulp mesenchymal stem cells were isolated and identified. Through in vitro screening experiments (berberine, curcumin, quercetin, and liquiritigenin), 2 μmol/L BBR was determined to be the optimal pretreatment concentration (verified by CCK-8 and apoptosis experiments).A TNBS-induced mouse IBD model was established,and mice were randomized into Control,TNBS,TNBS+DP-MSC,TNBS+BBR-pretreated DP-MSC(BBR-DPMSC) groups,the DP-MSC + AMD3100 group, and the BBR-DPMSC+AMD3100 group.(n = 6/group). DP-MSCs or BBR-DPMSCs were administered via tail vein injection.AMD3100(CXCR4 pathway blocker) was administered by intraperitoneal injection.The intestinal inflammation and immune regulatory effects were evaluated by colon length measurement, disease activity index (DAI) score, HE staining and pathological score, and ELISA (IL-1β,IL-6,IL-10,TGF-β,SDF-1,CXCR4). In vivo live imaging assessed DP-MSC homing. Transwell assays and CXCR4 inhibitor AMD3100 were used to verify the CXCR4/SDF-1 pathway.

RESULTS: In vitro screening demonstrated that berberine had the best pro-proliferative and anti-apoptotic effects on DP-MSCs among the four natural compounds (P < 0.01). In the IBD mouse model, compared with the untreated DP-MSCs, BBR-DPMSCs alleviated colonic shortening, reduced DAI scores, decreased intestinal mucosal damage and inflammatory cell infiltration, and regulated cytokine levels: lowering serum IL-1β and IL-6, and increasing anti-inflammatory factors IL-10 and TGF-β.Live imaging demonstrated that berberine significantly enhanced the homing efficiency of DP-MSCs to the injured intestine. In the TNBS model, SDF-1 was mainly highly expressed in the intestinal tissue, forming a specific chemotactic gradient. Transwell experiments confirmed that berberine promoted the migration of DP-MSCs in an SDF-1 concentration-dependent manner. Meanwhile, BBR could up-regulate the expression of CXCR4 in DP-MSCs. After blocking the CXCR4/SDF-1 pathway with AMD3100, the homing enhancement effect and therapeutic effect of the BBR-DP-MSC group were significantly decreased.

CONCLUSION: BBR pretreatment enhances the intestinal homing capacity of DP-MSCs via activating the CXCR4/SDF-1 signaling pathway, and exerts synergistic anti-inflammatory effects by upregulating IL-10 and TGF-β secretion, ultimately improving the therapeutic efficacy in IBD. This study provides a novel strategy for optimizing MSC-based immunotherapy of IBD by combining natural compounds with stem cells.