Long-term repopulation effects of donor BMDCs on intestinal epithelium.

BACKGROUND: Bone marrow-derived cells (BMDCs) have the ability to differentiate into intestinal epithelial cells after transplantation and participate in the regeneration process of damaged epithelium. AIMS: To investigate whether BMDCs could differentiate into intestinal epithelium long term in chimeric mice after transplantation and without special treatment. METHODS: Forty irradiated C57BL/6 mice were used. Thirty of them (group A) received transplantation of BMDCs from GFP transgenic mice, and ten (group B) received PBS. The chimeric percentage at the 14th month was examined by flow cytometry. Engraftment of BMDCs was detected by immunohistochemistry in intestinal epithelium. Immunofluorescence observation was used to detect coexpression of PCK, CD45 and Chromogranin A with GFP. BMDCs in the epithelium were observed by an immune electron microscope. The percent of GFP(+) epithelial cells was also determined by flow cytometry. RESULTS: Mice in group A had a survival rate of 93.3% 1 week after transplantation. BMDCs could engraft into recipients' intestinal epithelium. These cells expressed epithelial cell marker PCK, but could not express CD45. Some of them differentiated into enteroendocrine cells expressing Chromogranin A. GFP(+) villous epithelial cells ranged from 9.41 to 16.07% in different subgroups of group A. BMDCs in epithelium developed the characteristics of enterocytes and goblet cells. GFP(+)/PCK(+) epithelial cells at the 6th month made up a proportion of 16.11% among all the isolated epithelial cells. CONCLUSIONS: Long term, BMDCs could repopulate recipient's intestinal epithelium even without any special treatment, which suggests a novel insight into the maintenance of the intestinal epithelial constitution.