• 생체재료학회지
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• 제22권4호
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• pp.271-278
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• 2018

Background: The chondrogenic differentiation of mesenchymal stem cells (MSCs) is regulated by many factors, including oxygen tensions, growth factors, and cytokines. Evidences have suggested that low oxygen tension seems to be an important regulatory factor in the proliferation and chondrogenic differentiation in various MSCs. Recent studies report that synovium-derived mesenchymal stem cells (SDSCs) are a potential source of stem cells for the repair of articular cartilage defects. But, the effect of low oxygen tension on the proliferation and chondrogenic differentiation in SDSCs has not characterized. In this study, we investigated the effects of hypoxia on proliferation and chondrogenesis in SDSCs. Method: SDSCs were isolated from patients with osteoarthritis at total knee replacement. To determine the effect of oxygen tension on proliferation and colony-forming characteristics of SDSCs, A colony-forming unit (CFU) assay and cell counting-based proliferation assay were performed under normoxic (21% oxygen) or hypoxic (5% oxygen). For in vitro chondrogenic differentiation, SDSCs were concentrated to form pellets and subjected to conditions appropriate for chondrogenic differentiation under normoxia and hypoxia, followed by the analysis for the expression of genes and proteins of chondrogenesis. qRT-PCR, histological assay, and glycosoaminoglycan assays were determined to assess chondrogenesis. Results: Low oxygen condition significantly increased proliferation and colony-forming characteristics of SDSCs compared to that of SDSCs under normoxic culture. Similar pellet size and weight were found for chondrogensis period under hypoxia and normoxia condition. The mRNA expression of types II collagen, aggrecan, and the transcription factor SOX9 was increased under hypoxia condition. Histological sections stained with Safranin-O demonstrated that hypoxic conditions had increased proteoglycan synthesis. Immunohistochemistry for types II collagen demonstrated that hypoxic culture of SDSCs increased type II collagen expression. In addition, GAG deposition was significantly higher in hypoxia compared with normoxia at 21 days of differentiation. Conclusion: These findings show that hypoxia condition has an important role in regulating the synthesis ECM matrix by SDSCs as they undergo chondrogenesis. This has important implications for cartilage tissue engineering applications of SDSCs.

• 대한방사선기술학회지:방사선기술과학
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• 제25권2호
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• pp.77-82
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• 2002

이미 분화된 연골세포의 성숙과정에 미치는 X-선의 작용에 대해서는 잘 알려져 있다. 그러나 연골세포나 섬유아세포, 근육세포로 분화될 수 있는 미분화 간충직 세포의 분화과정에 미치는 X-선의 영향에 대해서는 잘 알려져 있지 않아, 본 연구에서는 초기 분화연구에 좋은 대상이 되는 계배 미분화 간충직세포를 이용하여 선량(1-10Gy)에 따라 연골세포 분화 과정에 X-선이 어떤 영향을 미치는가를 조사하였다. 연구결과 선량 의존적으로 연골세포분화가 억제됨을 alcian blue로 sulfated proteoglycan을 염색한 결과를 통해 알 수 있었다. 이는 X-선이 간충직세포와 같은 성숙 이전의 연골성 세포들에게는 모두 영향을 미침을 보여주는 것이다. 또한 이미 알려진 바와 같이 X-선은 분화된 연골세포의 성숙과정에 영향을 주기도 하지만 상기 연구를 통해서 간충직세포로부터 연골세포로 분화하는 과정을 억제시키기도 함을 보여줌으로써 간충직세포로부터 성숙된 연골세포로 되는 전과정에 X-선이 영향을 미친다는 사실과, 분화가 이루어지지 않은 세포일수록 X-선 조사의 영향을 크게 받음을 알 수 있다.