2012年10月31日 訊 /生物谷BIOON/ --來自杜克大學(xué)醫(yī)學(xué)中心的研究人員利用誘導(dǎo)性多能干細(xì)胞(iPSC)人工構(gòu)建出軟骨組織,，而且還能成功地培養(yǎng)出這種組織，從而可能利用它進(jìn)行組織修復(fù),，以及研究軟骨損傷和骨關(guān)節(jié)炎,。這一發(fā)現(xiàn)提示著iPSC可能一種重要的能夠被用來構(gòu)建出病人特異性的關(guān)節(jié)軟骨組織的來源。相關(guān)研究結(jié)果于10月29日在線刊登在PNAS期刊上。
論文第一作者Brian O. Diekman說,，“這種產(chǎn)生iPSC的技術(shù)是先獲取成體干細(xì)胞，然后對(duì)它們進(jìn)行轉(zhuǎn)化而讓它們具有胚胎干細(xì)胞的性質(zhì),。”
在一項(xiàng)新的研究中,，研究人員將在體外利用培養(yǎng)基培養(yǎng)的成年小鼠成纖維細(xì)胞重編程為iPSC，接著他們誘導(dǎo)iPSC分化為軟骨細(xì)胞,。他們同時(shí)對(duì)iPSC進(jìn)行改造,，從而讓它們只在分化為軟骨細(xì)胞時(shí)才表達(dá)綠色熒光蛋白(GFP),。當(dāng)iPSC分化時(shí)，發(fā)生綠色熒光的軟骨細(xì)胞很容易被鑒定出和從其他不想要的細(xì)胞中被分離開來,。
這些經(jīng)過改造的iPSC也產(chǎn)生更加大量的軟骨組分,，包括骨膠原，并且表現(xiàn)出天然軟骨的特征性硬度,，這就提示著它們將很可能能夠修復(fù)體內(nèi)的軟骨缺陷,。
Diekman說，“這是一個(gè)多步驟的方法：首先進(jìn)行分化,，然后進(jìn)行分離,，最后利用分離到的細(xì)胞構(gòu)建組織。這項(xiàng)研究證實(shí)iPSC能夠被用來制造出高質(zhì)量的軟骨來作為替換組織或者被用來研究疾病或開發(fā)出潛在的治療方法,。”
doi: 10.1073/pnas.1210422109
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PMID:
Cartilage tissue engineering using differentiated and purified induced pluripotent stem cells
Brian O. Diekmana,b, Nicolas Christoforoub,c, Vincent P. Willarda, Haosi Suna,b, Johannah Sanchez-Adamsa, Kam W. Leongb, and Farshid Guilak
The development of regenerative therapies for cartilage injury has been greatly aided by recent advances in stem cell biology. Induced pluripotent stem cells (iPSCs) have the potential to provide an abundant cell source for tissue engineering, as well as generating patient-matched in vitro models to study genetic and environmental factors in cartilage repair and osteoarthritis. However, both cell therapy and modeling approaches require a purified and uniformly differentiated cell population to predictably recapitulate the physiological characteristics of cartilage. Here, iPSCs derived from adult mouse fibroblasts were chondrogenically differentiated and purified by type II collagen (Col2)-driven green fluorescent protein (GFP) expression. Col2 and aggrecan gene expression levels were significantly up-regulated in GFP+ cells compared with GFP− cells and decreased with monolayer expansion. An in vitro cartilage defect model was used to demonstrate integrative repair by GFP+ cells seeded in agarose, supporting their potential use in cartilage therapies. In chondrogenic pellet culture, cells synthesized cartilage-specific matrix as indicated by high levels of glycosaminoglycans and type II collagen and low levels of type I and type X collagen. The feasibility of cell expansion after initial differentiation was illustrated by homogenous matrix deposition in pellets from twice-passaged GFP+ cells. Finally, atomic force microscopy analysis showed increased microscale elastic moduli associated with collagen alignment at the periphery of pellets, mimicking zonal variation in native cartilage. This study demonstrates the potential use of iPSCs for cartilage defect repair and for creating tissue models of cartilage that can be matched to specific genetic backgrounds
