German Matthew J, Pollock Hubert M, Zhao Bojun, Tobin Mark J, Hammiche Azzedine, Bentley Adam, Cooper Leanne J, Martin Francis L, Fullwood Nigel J
Biomedical Sciences, Department of Biological Sciences, Lancaster University, UK.
Invest Ophthalmol Vis Sci. 2006 Jun;47(6):2417-21. doi: 10.1167/iovs.05-1254.
High-resolution synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopy coupled with multivariate analysis was used to investigate the characteristics of putative adult stem cell (SC), transiently amplified (TA) cell, and terminally differentiated (TD) cell populations of the corneal epithelium.
Spectra of individual cells in situ in cryosections of bovine cornea were collected by using a synchrotron microspectroscopy facility at Daresbury Laboratory (United Kingdom). The resultant spectra were analyzed by multivariate analysis.
The median spectra of the three different cell populations showed marked differences, which correlated with their degree of differentiation and proliferative capacity. Multivariate (principal component) analysis (PCA) showed that the three cell populations could be segregated into discrete clusters, with only a slight overlap between the SC and TA cell populations. Further analysis (Mann-Whitney test) indicated that the most significant (P<0.001) spectral differences between the SC and TA cell populations were chiefly associated with changes in nucleic acid conformation.
SR-FTIR microspectroscopy coupled with PCA appears to enable the identification of SC, TA cell, and TD cell populations. The results also suggest that a small subpopulation of cells in the corneal epithelial SC niche possess TA cell-like characteristics. The most significant spectral characteristics associated with the SCs appear to relate to differences in nucleic acid conformation. This finding is consistent with recent theories suggesting that the control of differentiation is related to major changes in chromatin structure.
采用基于高分辨率同步辐射的傅里叶变换红外（SR-FTIR）显微光谱技术并结合多变量分析，研究角膜上皮中假定的成体干细胞（SC）、短暂扩增（TA）细胞和终末分化（TD）细胞群体的特征。
利用英国达累斯伯里实验室的同步辐射显微光谱设备，收集牛角膜冰冻切片中单个细胞的原位光谱。对所得光谱进行多变量分析。
三种不同细胞群体的中位光谱显示出明显差异，这与其分化程度和增殖能力相关。多变量（主成分）分析（PCA）表明，这三种细胞群体可分为离散的簇，SC和TA细胞群体之间只有轻微重叠。进一步分析（曼-惠特尼检验）表明，SC和TA细胞群体之间最显著（P<0.001）的光谱差异主要与核酸构象的变化有关。
SR-FTIR显微光谱技术结合PCA似乎能够识别SC、TA细胞和TD细胞群体。结果还表明，角膜上皮SC生态位中的一小部分细胞亚群具有TA细胞样特征。与SCs相关的最显著光谱特征似乎与核酸构象的差异有关。这一发现与最近提出的分化控制与染色质结构的重大变化有关的理论一致。
