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골수 유래 중간엽 줄기세포의 연골화 분화에 저강도 초음파의 자극이 미치는 영향
- Alternative Title
- Hyun Jung Lee
- Author(s)
- 이현정
- Alternative Author(s)
- Hyun Jung Lee
- Advisor
- 민병현
- Department
- 일반대학원 분자과학기술학과
- Publisher
- The Graduate School, Ajou University
- Publication Year
- 2007-08
- Language
- eng
- Keyword
- Low-intensity ultrasound; chondrogenic differentiationa bone marrow mesenchymal stem cells; alginate culture; viability; apoptosis; surface markers; flow cytometry
- Alternative Abstract
- Bone marrow mesenchymal stem cells (MSC) are known as progenitor cells capable of differentiation into osteoblasts, chondrocytes, adipocytes, myocytes. Many growth factors, cytokines and mechanical stimulation are known to affect chondrogenic differentiation of MSC, however, the mechanisms of how these factors affect chondrogenic differentiation remain unclear. To date, three-dimensional (3-D) culture and TGF-β are known as one of essential factors for chondrogenic differentiation. Recently, low-intensity ultrasound (LIUS) has been demonstrated to have the effects on the enhancement of fracture healing via increasing the chondrogenesis, which suggests that LIUS could affect in chondrogenic differentiation of MSC. The aim of these studies is to investigate the effect of LIUS treatment on the chondrogenic differentiation of MSCs. When LIUS is applied on the chondrogenesis of rabbit MSCs (rMSCs) in a 3-D alginate culture and after replating them on a monolayer culture, we found the increases of the matrix formation, the expression of chondrogenic markers such as collagen type II, aggrecan, and Sox-9, the expression of tissue inhibitor of metalloprotease - 2 implicated in the integrity of cartilage matrix, and the capacity to maintain the chondrogenic phenotypes in a monolayer culture. The 3-D alginate culture and the TGF-β1 treatment on chondrogenic differentiation system of human MSCs (hMSCs) resulted in the decrease of cell viability, which appeared to be mediated by apoptosis. In contrast, co-treatment of LIUS clearly enhanced cell viability and inhibited apoptosis under the same condition. The LIUS effect on the apoptotic event was further supported by the changes in the expression of apoptosis/viability related genes of p53, bax, bcl-2 and PCNA. Next, we examined the surface markers showing specific changes during the chondrogenic differentiation and dedifferentiation of hMSCs. hMSCs from adult bone marrow were subjected to chondrogenic differentiation in 3-D alginate culture with TGF-β3 for 2 weeks, followed by dedifferentiation in monolayer for 1 week. Surface antigens were selected from those showing expression changes during dedifferentiation of human articular chondrocytes (hACs). The results from flow cytometry identified 3 groups of surface antigens with differential expression patterns, but showed quite different from those shown in hACs reported previously. The groups 1 and 2 antigens were expressed at high levels in hMSCs. The expression of group 1 antigens (CD44, CD58, CD90, CD105 and CD166) decreased non-specifically just by 3-D alginate culture, while that of group 2 antigens (CD49c, CD49e, CD81 and CD151) decreased depending on the chondrogenic differentiation. The expression of group 3 antigens was not significantly observed at all experimental stages. Interestingly, the LIUS treatment showed no effect at all on the changes in their expression during the stages. Notably, LIUS effects were clearly shown even without TGF-β treatment. These finding demonstrate that LIUS stimulated chondrogenic differentiation of bone marrow MSC. LIUS treatment could be a valuable tool for cartilage tissue engineering using MSCs by enhancing the cell viability as well as by directing the chondrogenic differentiation process, its well-known activity. Our observation shows that the noninvasive ultrasound function as a kind of chondrogenic mechanical stimulus suggests potential clinical applications in cartilage repair.
- Fulltext
- Appears in Collections:
- Graduate School of Ajou University > Department of Molecular Science and Technology > 3. Theses(Master)
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