World Congress of Gastroenterology

WCOG 2019


 
Effects and mechanism of conditioned medium derived from bone marrow mesenchymal stem cell with inflammatory activation on regeneration of radiation-induced intestinal injury in vitro
CHEN ZHANG 1 HAO CHEN 1 WEIHONG SHA 1

1- GUANGDONG PROVINCIAL GERIATRICS INSTITUTE
 
Background/Aims:

 Conditioned medium from mesenchymal stem cells (MSC-CM) may represent a promising alternative to MSCs transplantation. Our previous study has demonstrated that MSC-CM with inflammatory activation improves the structural and functional restoration of the small intestine after radiation-induced intestinal injury, improving the survival status of rats with acute radiation injury, but its potential cellular mechanism has not been further explored. To observe the effect of MSC-CM with inflammatory activation on the proliferation and apoptosis of intestinal epithelial cells (IEC-6) after radiation injury and to investigate the cellular mechanism of pre-activated MSC-CM in repairing the small intestinal mucosa. 

Materials and Methods:

 IEC-6 cells were divided into four groups: control group, radiation injury group, normal MSC-CM (MSC-CMIEC-6(NOR)) group and inflammatory pre-activated MSC-CM (MSC-CMIEC-6(IR)) group. IEC-6 cells in the latter three groups were exposed to 10 Gy X-ray irradiation and cultured in DMEM-F12 medium, MSC-CMIEC-6(IR) and MSC-CMIEC-6(NOR) respectively. Cells in the control group were only cultured in DMEM-12 medium. Cultured cells were collected at 3 days after radiation to observe the proliferation of IEC-6 cells by using proliferating cell nuclear antigen immunofluorescence staining, and to observe the apoptosis by using TUNEL apoptosis staining and western blot assay.

Results:

 Compared with the radiation injury group, in the MSC-CMIEC-6(IR) group, the number of cells positive for proliferating cell nuclear antigen increased significantly (P < 0. 05), the number of TUNEL positive cells decreased significantly (P < 0. 05), and the expression of Caspases-3 decreased significantly (P < 0.05), However, there was no significant difference between the MSC-CMIEC-6(NOR) group and radiation injury group (P > 0.05). 

Conclusion:

 MSC-CMIEC-6(IR), but not non-activated MSC-CM, significantly promotes the proliferation and reduces apoptosis of intestinal epithelial cells after radiation injury and therefore repair the injured intestinal tissue.

Keywords:

Mesenchymal stem cells;Conditioned medium;Small intestine;Radiation-induced injury;Paracrine