Bone marrow mesenchymal stem cells from pigs inhibit inflammatory response induced by lipopolysaccharide and improve islet cell dysfunction in pigs / 中国组织工程研究

ABSTRACT

BACKGROUND: Porcine pancreatic islet transplantation is a common treatment for diabetes mellitus, but inflammatory reaction and oxidative stress can lead to poor long-term effect. It has been confirmed that transplantation of porcine bone marrow mesenchymal stem cells with islets can improve graft function. However, it has not been reported that porcine bone marrow mesenchymal stem cells regulate the expression of miR-299-5p in islet cells to regulate the function and survival rate of islet β cells. OBJECTIVE: To investigate the effects of bone marrow mesenchymal stem cells in pigs on functional impairment of islet in pig by regulating the JNK/C-Jun pathway through the miR-299-5p/SIAH1 molecular axis. METHODS: Lipopolysaccharide was used to induce functional impairment of porcine islet cells, which were co-cultured with bone marrow mesenchymal stem cells for 24 hours. Interleukin-6, interleukin-1β, tumor necrosis factor-α, reactive oxygen species, superoxide dismutase and insulin levels in islet cells were detected by ELISA. Hoechst 33258 staining was used to observe apoptosis. Annexin V-FITC/PI was used to detect the apoptosis rate of porcine islet cells. Western blotting was used to detect the expression of SIAH1 and proteins associated with JNK/C-Jun pathway. The expression of miRNAs in porcine islet cells was detected by qPCR. The dual-luciferase reporter gene assay verified the targeting relationship between miR-299-5p and SIAH1. RESULTS AND CONCLUSION: (1) Bone marrow mesenchymal stem cells in pigs inhibited the up-regulation of interleukin-6, interleukin-1β, tumor necrosis factor-α, reactive oxygen species and pro-apoptotic effects, and also inhibited the down-regulation of superoxide dismutase and insulin secretion induced by lipopolysaccharide. (2) Bone marrow mesenchymal stem cells of pigs significantly upregulated miR-299-5p expression. miR-299-5p inhibited activation of the JNK/C-Jun pathway by down-regulating SIAH1 expression. (3) Results indicate that bone marrow mesenchymal stem cells of pigs inhibit the activation of the JNK/C-Jun pathway, inhibit the inflammatory response, oxidative stress and apoptosis of islet cells in pigs, and promote the secretion of insulin by regulating the miR-299-5p/SIAH1 axis, hereby improving the functional damage of porcine islet cells.