Protective effects of CXCR3/HO‑1 gene‑modified BMMSCs on damaged intestinal epithelial cells: Role of the p38‑MAPK signaling pathway.

The purpose of the present study was to investigate whether bone marrow mesenchymal stem cells (BMMSCs) modified by CXC‑chemokine receptor type 3 (CXCR3) and heme oxygenase‑1 (HO‑1) genes can repair damaged intestinal epithelial cells in vitro, and the role of the p38 mitogen‑activated protein kinase (p38‑MAPK) pathway in this process. A model of intestinal epithelial crypt cell line‑6 (IEC‑6) damage was created, and BMMSCs were transfected with either the CXCR3 and/or HO‑1 gene in vitro. There were nine experimental groups in which the damaged IEC‑6 cells were co‑cultured with differentially‑treated BMMSCs and lymphocytes for 24 h. Reverse transcription‑quantitative polymerase chain reaction analysis, immunohistochemistry and a western blot analysis were performed to detect stem cell transfection, the repair of damaged intestinal epithelial cells and the expression of related molecules in the P38‑MAPK pathway, respectively. Crystal violet staining and live cell imaging were used to detect the chemotaxis of BMMSCs. Flow cytometry was used to detect T lymphocyte activity and the surface markers expressed on BMMSCs. An ELISA was used to quantify cytokine production. The adenovirus (Ad)‑CXCR3/MSCs exhibited the characteristics of stem cells and exhibited chemotaxis. The Ad‑CXCR3/MSCs and Ad‑(CXCR3 + HO)/MSCs exhibited increased expression of tight junction protein zonula occludens‑1 (ZO‑1) and anti‑proliferating cell nuclear antigen in the damaged IEC‑6 cells, and apoptosis of the damaged IEC‑6 cells was decreased. BMMSCs inhibited the phosphorylation of p38, in addition to downstream molecules of the p38MAPK signaling pathway. The Ad‑CXCR3/MSCs and Ad‑(CXCR3 + HO)/MSCs exhibited significantly decreased expression levels of downstream molecules, including phosphorylated (p)‑p38, p‑activated transcription factor 2, p‑C/EBP homologous protein‑10, and p‑myocyte enhancer factor 2C, and target molecules (e.g., apoptotic bodies). The effects of Ad‑(CXCR3 + HO)/MSCs on the repair of the damaged intestinal tract and inhibition of the p38‑MAPK pathway was more marked than those in other groups on day 7 post‑surgery in the rejection model for small bowel transplantation. BMMSCs modified by the CXCR3 and HO‑1 genes exhibited superior ability to repair damaged intestinal epithelial cells and served this role via the p38‑MAPK pathway.