羊膜上皮细胞的生物学特性和骨向分化

Biological characteristics and osteogenic differentiation of amniotic epithelial cells

人羊膜上皮细胞(hAEC)位于羊膜最内层,外侧包绕人羊膜间质细胞(hAMC)和细胞外基质。hAEC具有典型的上皮细胞样形态和超微结构,而hAMC表现出上皮-间质混合超微结构特征。这些来自于羊膜的特殊干细胞群可表达八聚体4、关键蛋白、氧化还原调节器1和Y染色体性别决定区相关高速泳动族蛋白盒2等干细胞标志物,可能较成体干细胞具有更高的多向分化潜力。体外骨诱导培养均可促进hAEC和hAMC的碱性磷酸酶水平增高,1型胶原和骨钙蛋白等成骨标志物表达,细胞外矿化组织增加。最近的研究显示,将羊膜上皮细胞植入动物骨缺损后,可观察到细胞快速广泛地成骨分化,且细胞可在移植部位存活45 d并持续形成新生骨。作为一类处于胚胎干细胞和成体干细胞过渡阶段的特殊干细胞样细胞,hAEC在颌面部骨组织再生方面具有潜在的研究和应用价值,值得国内外同行共同探索研究。

Human amniotic epithelial cells（hAEC） are located in the inner layer of the amniotic membrane and surrounded by human amniotic mesenchymal cells（hAMC） and an extracellular matrix, hAEC has a typical epithelial cell-like morphology and an ultra-structure, whereas hAMC exhibits mixed epithelial-mesenchymal, ultrastructural features. These amniotic derived stem cells can express octamer 4, Nanog, redox regulator 1, sex determination region of Y chromosome-related high mobility group-box 2, and other stem cell markers, which may indicate a higher multi-lineage differentiation potential than adult stem cells. In vitro osteoblastic culture can promote the bone alkaline phosphatase level, osteoblast marker expression（such as type 1 collagen and osteocalcin）, and extracellular mineralization in hAEC and hAMC. A recent study have shown that amniotic epithelial cells implanted into an animal bone defect can undergo rapid osteogenic differentiation and survive for 45 d with the continuous formation of a new bone in the transplantation site. As a transitional class between embryonic and adult stem cells with special stem cell-like characteristics, hAEC possesses potential applications in research and maxillofacial bone regeneration; thus, researchers believe that hAEC is worthwhile to study.