[Preliminary study on human bone marrow mesenchymal stem cells differentiation into epithelial-like cells].

Objective: To investigate the differentiation potential of human bone marrow mesenchymal stem cells (hMSC) inducing into epithelial-like cells, even corneal epithelial-like cells, and to discuss the plasticity that make hMSC the seed cells used in corneal tissue engineering.

Methods: hMSC were isolated and purified by density gradient centrifugation combined with an attachment culture method and passaged in vitro. hMSC were identified by flow cytometry. The passaged hMSC were planted on fresh pig corneal Bowman's membrane. The expression of CK12, ABCG2 and CK19 in hMSC was identified by immunofluorescence staining. We used in vitro method to obtain a multilayer culture of hMSC. When hMSC formed a monolayer, the cells were inserted to Millicell culture and grew into multilayers by using the air-lifting cultivation methodology. Four weeks later, after fixed and dehydrated, the hMSC were observed under the light microscope after hemotoxylin and eosin (HE) and immunohistochemistry staining.

Results: hMSC could be cultured, expanded in vitro, and showed great potential of proliferation. The result of flow cytometry showed that the positive staining percentage was 0.06% for CD45, 0.41% for CD34, 86.43% for CD44, 85.72% for CD29 and 90.72% for CD105. This indicated that hMSC expressed CD44, CD29, CD105 but not CD45 and CD34. After four weeks induction, part of hMSC expressed CK12 and CK19 but not ABCG2. In the in vitro stratification, HE and immunohistochemical staining showed that there were one or two layers epithelial-like cells, even corneal epithelial-like cells after using the air-lifting cultivation.

Conclusions: This study suggests that hMSC have the potential to differentiate into epithelial cells, even corneal epithelial cells. hMSC could be the option of cells used to reconstruct the corneal epithelium by tissue engineering technology.