Objective    To observe the possibility that bone marrow mesenchymal stem cells (BMSCs) induced by fetal intestinal connective tissue differentiate into epithelial cells.     Methods    The fetal intestinal tissue lumps composed of mucosa and submucosa were prepared with informed consent and approval of the Ethics Committee of our university

and the intestinal epithelium was removed with enzymatic digestion. The 3

rd

generation cells of fetal BMSCs labeled with DAPI were planted on the surface of the bowel submucosa

and divided into group A (EGF added) and group B (without EGF addition). BMSCs attac

hed to cover glass were set as control groups C and D. After BMSCs were cultured in vitro for 12 d

their morphological

histochemical and immunohistochemical analysis was performed under light microscope and CLSM.     Results    The DAPI labeled cells could be seen on the surface of tissue lumps by fluorescence microscope

and in the same section stained by HE

these cells looked morphologically like epithelial cells. Immunohistochemical staining showed that the cells on the surface of tissue lumps in groups A

B and C expressed CK and CK20

but not in group D. EGF expressed in intestinal connective tissues. The double fluorescent labelling cells with blue DAPI and red CK or green EMA could be seen on the surface of tissue lumps observed by CLSM. The basal lamina-like structure appeared between the cells and connective tissues in PAS reaction.     Conclusion    The intestinal connective tissues could induce BMSCs to differentiate into epithelial cells

and the endogenous EGF may be one of factors in this process.