Age and topographical comparison of telomere lengths in human corneal endothelial cells.
Age and topographical comparison of telomere lengths in human corneal endothelial cells.
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发表时间：
2007-07
期刊：
影响因子：
2.2
通讯作者：
K. Konomi;N. Joyce
中科院分区：
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作者：
K. Konomi;N. Joyce
目的人角膜内皮细胞在相对增殖能力和衰老特性方面表现出年龄相关性和地形性差异。这些研究的目的是比较年轻和老年供者角膜中央和周围区域的人角膜内皮细胞(HCEC)的端粒长度，以确定这些变化可能是由于复制性衰老还是应激诱导的早衰。方法用直径9.5 mm的环钻去除巩膜组织，用直径6.0 mm的环钻标记中央-外周边界，将5例65岁青年的角膜分成中央区和周边区。将其中一对角膜切成四份，用与端粒重复序列特异结合的多肽核酸(PNA)/异硫氰酸荧光素(PNA/FITC)探针进行染色。取第二角膜中央(0~6.0 mm)和周边(6.0~9.5 mm)的HCEC，用Cytspin固定在玻片上，用PNA/FITC探针染色。用荧光共聚焦显微镜获取数字图像。比较两个年龄组内和两个年龄组之间中心区和周边区细胞核的平均FITC强度。以Ccl185和1301细胞为对照。采用学生非配对t检验确定数据的统计学意义。结果中心内皮细胞平均荧光强度为205.8+/-4.2(青年)和194.2+/-10.5(老年)，外周内皮平均荧光强度为208.1+/-9.3(青年)和195.9+/-10.8(老年)。从中央内皮分离的单个细胞平均强度为113.9+/-31.1(年轻)和107.9+/-26.1(老年)，从外周分离的单个细胞平均强度为109.9+/-12.0(年轻)和106.9+/-32.4(老年)。Ccl185细胞和1301细胞的平均荧光强度分别为5 0.5+/-5.0和206.9+/-19.4。结果的比较表明，在每个组内的中央和外围区域之间，或者在年轻和老年组之间，在统计学上没有显著差异。结论在HCEC中观察到的相对增殖能力和衰老特征的年龄相关性和地形性降低不是由于端粒过短引起的复制性衰老，而是应激诱导的早衰是这些临床重要变化的原因之一。
PURPOSE Human corneal endothelium exhibits both age-related and topographical differences in relative proliferative capacity and in senescence characteristics. The purpose of these studies was to compare telomere lengths in human corneal endothelial cells (HCEC) from the central and peripheral areas of corneas from young and older donors to determine whether these changes may be due to replicative senescence or to stress-induced premature senescence. METHODS Pairs of corneas from five young (65 years old) were separated into central and peripheral areas using a 9.5 mm diameter trephine to remove scleral tissue and a 6.0 mm diameter trephine to mark the central-peripheral boundary. One of the pair of corneas was cut into quarters and stained with a peptide nucleic acid (PNA)/fluorescein isothiocyanate (PNA/FITC) probe that specifically binds to telomere repeats. HCEC from the central (0-6.0 mm) and peripheral areas (6.0-9.5 mm) were isolated from the second cornea, mounted on slides by Cytospin, and stained with the PNA/FITC probe. Fluorescence confocal microscopy was used to obtain digital images. The average FITC intensity of nuclei was compared between the central and peripheral areas within and between the two age groups. Ccl185 and 1301 cells were analyzed as controls. Student's unpaired t-test was used to determine the statistical significance of the data. RESULTS Average FITC intensity from the central endothelium was 205.8+/-4.2 (younger) and 194.2+/-10.5 (older) and from the peripheral endothelium was 208.1+/-9.3 (younger) and 195.9+/-10.8 (older). Average intensity of single cells isolated from central endothelium was 113.9+/-31.1 (younger) and 107.9+/-26.1 (older) and from the periphery was 109.9+/-12.0 (younger) and 106.9+/-32.4 (older). Average FITC intensity of Ccl185 cells and 1301 cells was 50.5+/-5.0 and 206.9+/-19.4, respectively. Comparison of the results indicates no statistically significant difference between the central and peripheral areas within each group or between the young and older age group. CONCLUSIONS Results indicate that the age-related and topographical reduction in relative proliferative capacity and senescence characteristics observed in HCEC are not due to replicative senescence caused by critically short telomeres but implicate stress-induced premature senescence as a cause of these clinically important changes.