Abstract:
The anterior lens epithelium has the ability to differentiate into lens fibres throughout its life. The present study aims to identify and functionally characterize the adult stem cells in the human lens epithelium. Whole mounts of lens epithelium from donor eyes (normal/cataract) were immunostained for SOX2, gap junction protein alpha 1 (GJA1), PAX6, α, β and γ-crystallins, followed by a confocal analysis. The functional property of adult stem cells was analysed by their sphere forming ability using cultured lens epithelial cells from different zones. Based on marker expression, the lens epithelium was divided into four zones: the central zone, characterized by a small population of PAX6+, GJA1-, β-crystallin- and γ-crystallin- cells; the germinative zone, characterized by PAX6+, GJA1+, β-crystallin- and γ-crystallin-; the transitional zone, characterized by PAX6+, GJA1+, β-crystallin+ and γ-crystallin-; and the equatorial zone, characterized by PAX6+/-, GJA1+, β-crystallin+, and γ-crystallin+ cells. The putative lens epithelial stem cells identified as SOX2+ and GJA1 membrane expression negative cells were located only in the central zone (1.89 ± 0.84%). Compared to the other zones, a significant percentage of spheres were identified in the central zone (1.68 ± 1.04%), consistent with the location of the putative adult lens epithelial stem cells. In the cataractous lens, an absence of SOX2 expression and a significant reduction in sphere forming ability (0.33 ± 0.11%) were observed in the central zone. The above findings confirmed the presence of putative stem cells in the central zone of the adult human lens epithelium and indicated their probable association with cataract development.
摘要:
晶状体前上皮具有在其整个生命周期中分化为晶状体纤维的能力。本研究旨在鉴定和功能表征人晶状体上皮中的成体干细胞。对来自供体眼(正常/白内障)的整个晶状体上皮进行SOX2,间隙连接蛋白α1(GJA1)免疫染色,PAX6,α,β和γ-晶状体蛋白,然后进行共焦分析。使用来自不同区域的培养的晶状体上皮细胞,通过成体干细胞的球体形成能力来分析成体干细胞的功能特性。基于标记表达,晶状体上皮分为四个区域:中央区,以少量PAX6+为特征,GJA1-,β-晶状体蛋白和γ-晶状体蛋白细胞;萌发区,以PAX6+为特征,GJA1+,β-晶状体蛋白和γ-晶状体蛋白;过渡区,以PAX6+为特征,GJA1+,β-晶状体蛋白+和γ-晶状体蛋白-;和赤道带,以PAX6+/-为特征,GJA1+,β-晶状体蛋白+,和γ-晶状体蛋白+细胞。鉴定为SOX2+和GJA1膜表达阴性细胞的假定晶状体上皮干细胞仅位于中央区(1.89±0.84%)。与其他地区相比,在中心区发现了相当大比例的球体(1.68±1.04%),与假定的成人晶状体上皮干细胞的位置一致。在白内障晶状体中,在中心区观察到SOX2表达缺失和球体形成能力显著降低(0.33±0.11%)。上述发现证实了成人晶状体上皮中央区域中假定的干细胞的存在,并表明它们可能与白内障发展有关。