Proteomic Analysis Of Human Bone Marrow-derived Mesenchymal Stem Cells Induced To Differentiate Into Osteoblasts

AIM: To analyze the difference of protein profiles between human bonemarrow-derived mesenchymal stem cells (MSC) and osteogenic differentiated MSC by proteomic approach.METHODS: The MSC were isolated primarily from bone marrow of adults and detected in cell purity by flow cytometry analyzing cell phenotypes and in cell function by multilineage potential test. The undifferentiated MSC and osteogenic differentiated MSC over a period of 14d were collected and cell total proteins were extracted for finding out the different expressing by proteomic including 2-D gel electrophoresis and Peptide Mass Fingerprinting technology.RESULTS: The MSC has been successfully obtained from human bonemarrow of adults. More than 80% MSC were fused on about 14d. Among surface antigens,CD73,CD105,CD166 were positive, while CD34,CD45 were negative. About 90% of MSC were found at G0-G1 phase by flow cytometry. To assess the adipogenic potential, cells were plated and cultured in adipogenic medium. The formation of neutral lipid vacuoles was noticeable as early as 1 week after induction and visualized by staining with oil-red O. To investigate the osteogenic potential, cells were plated and cultured in osteogenic medium, After 1 week of induction; The osteoblastic phenotype was shown by the expression of marker genes ALP. After 3 weeks.formed mineralized matrix as evidenced by von Kossa staining. The chondrogenic potential of MSC was evaluated by culturing under the pelleted micromass system in serum-free chondrogenic medium. After 3 weeks of differentiation, the expression of type II collagen was positive. The undifferentiated MSC and osteogenic differentiated MSC over a period of 14d were collected and cell total proteins were extracted for finding out the different expressing by proteomic including 2-D gel electrophoresis and Peptide Mass Fingerprinting technology. Twenty-four differently expressed proteins were identified by MALDI-TOF-MS analysis.CONCLUSION: Proteomic approach is a high throughput method to screen the key proteins which play important roles in MSC osteogenic differentiation.