Expression of Cell Surface Marker on Human Bone Marrow Derived Stromal Cells during Chondrogenic Differentiation / 대한류마티스학회지

ABSTRACT

OBJECTIVE: Multipotent bone marrow stromal cells have the ability to differentiate toward a variety of connective tissue lineages including cartilage. The future use of adult mesenchymal stem cells (MSCs) for human therapies depends on the establishment of preclinical studies. Therefore, in this preclinical study we demonstrated the expression of MSC surface markers CD29, CD105, and CD44 on human bone marrow derived stromal cells during chondrogenic differentiation. METHODS: Adult human bone marrow was collected from the iliac crest of 7 donors following informed consent. Mononuclear cells were isolated, incubated in monolayers, and embedded in alginate beads for three-dimensional cultures. Cellualr viability was assessed by MTT assay. Flow cytometry of alginate bead cultures was performed on days 0, 7, 14, 21, and 28 using monoclonal antibody against surface molecules, CD105, CD29, CD44, CD34 and CD45. Total contents of collagen and glycosaminoglycan (GAG) of the alginate beads was measured. SPSS 11.0 was used for data analysis. RESULTS: After 7 days of culture, 89% of the cells expressed the human integrin beta 1 antibody, CD29. The CD29-positive cells remained elevated at 83% on days 28. However, while only 18% expressed the type II TGF-beta receptor endoglin, CD105 on day 7, the CD105-positive cells increased abruptly 65% on day 14 remaining elevated up to day 28. The expression of CD44 was maximal in the first passage cell (63%). High concentration of TGF-beta 3 (10 ng/mL) was more favorable for sustaining cell viability than a low concentration (0.5 ng/mL)(n=4, p= 0.002, day 21). The total contents of collagen and GAG in the MSC-alginate beads increased during the three-dimensional culture (n=4, p=0.02, p=0.006) suggesting its differentiation into a chondrogenic lineage. CONCLUSION: CD29 was expressed earlier than CD105 during chondrogenic differentiation of human bone marrow MSC. CD44 expression was highest in the first passage cells and gradually decreased afterwards.