不沾黏生物分子對間葉幹細胞分化為軟骨細胞的影響

軟骨的復元是極為緩慢的，對關節軟骨受傷的病患，目前多以軟骨移植的手段幫助關節恢復功能，但人體自身可取用的軟骨極為有限，這成為修復關節軟骨的一大障礙。間葉幹細胞具有分化為表皮、肌肉、脂肪、軟骨及骨母等細胞的能力，已經成功的用於關節軟骨的修補，但對於生長環境對間葉幹細胞分化路徑的影響，目前的了解還是有限。關節軟骨的組成以水分最多，其次是第二型膠原蛋白(Collagen II)和胺多醣 (Glycosaminoglycans，GAG)。軟骨細胞可份泌膠原蛋白與胺多醣，軟骨便是由於collagen II和胺多醣結合，規則而緊密的排列而形成，文獻中顯示以第一型膠原蛋白(collagen I)為基質會誘導間葉幹細胞朝骨細胞分化，而在第一型膠原蛋白加入胺多醣，則會使間葉幹細胞朝軟骨細胞分化。另外有研究顯示，以瓊脂(agarose)包覆細胞進行培養，則間葉幹細胞也會朝軟骨細胞分化。由此，我們懷疑培養間葉幹細胞基質的表面性質，將影響其分化方向，特別是表面的黏著性與細胞的貼附性。本研究擬以貼附性極佳的第一型膠原蛋白為基質，控制組是接上chondroitin sulfate做為適合軟骨細胞生長的控制組，實驗組是以 iodopropionic acid 進行collagen I的表面改質，形成降低蛋白貼附性的zwitterionic結構，用以降低細胞在基質表面的貼附性，試圖以改變間葉幹細胞的貼附性來探討貼附性對其分化的影響。我們以細胞內aggrecan，collagen II，及SOX9 mRNA的表現來偵測間葉幹細胞也會朝軟骨細胞分化的程度，結果發現增加chondrotin sulfate在collagen I的接枝量，的確會增加aggrecan，collagen II，及SOX9的表現量，而隨著增加1 wt%、3wt%、5 wt%、7 wt% Iodopropionic acid的接枝量，同樣會使aggrecan，collagen II，及SOX9的表現量增加，直到改質9wt% Iodopropionic acid，其aggrecan，collagen II，及SOX9的表現量呈現減少的狀態。關鍵詞: 表面沾粘性、軟骨、間葉幹細胞

關鍵字

表面沾粘性；間葉幹細胞；軟骨

並列摘要

Cartilages are poorly vascularized tissues with weak capacity for self-repair. Therre are many causes of cartilage degeneration. The degenerated cartilages will never heal. Autologous transplants has been developed to repair articular cartilage and shown some success. Brittberg et al. has seeded autologous chondrocytes in wounded sites by extracting chondrocytes from a low weight-bearing region of the body and expanded in vitro. But we usually lacks the source of autologous chondrocytes. Mesenchymal stem cells (MSCs) have the capacity to differentiate toward epithelials, adiposes, myoblasts, osteoblasts, or chondrocytes, and have been successfully adopted in cartilage repair. However, the process of chondrogenesis of MSC has not been fully understood. The major component of cartilage is water, and the rest are type II collagen and glycosaminoglycans. The type II collagen and glycosaminoglycans are actually secreted by chondrocytes. Studies has shown that type I collagen induced MSCs to differentiate toward osteoblasts. But the addition of GAGs shifted the differentiation toward chondrocytes. Other studies showed that MSCs cultivated on agarose differentiated toward chondrocytes. This study aims at finding out the effect of surface adhesivity on mesenchymal stem cell differentiation. We tried to cultivate MSCs on the surface of collagen I. The surface adhesivity of collagen I was altered by grafting various amount of non-adhesive polymer, Iodopropionic acid. The expression of aggrecan, collagen II, and SOX9 were measured as the indication of chondrogenesis. It was found that the expression of aggrecan, collagen II，and SOX9 increased as the grafting density of chondroitin sulfate increased. Similarly, the chondrogenesis indication also increased with the increase in Iodopropionic acid content. Key words: Surface adhesivity,Chondrocyes,Mesencymal stem cell

並列關鍵字

Surface adhesivity ； Mesencymal stem cell ； Chondrocytes

參考文獻

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不沾黏生物分子對間葉幹細胞分化為軟骨細胞的影響

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