Patek C E, Jeanny J C, Clayton R M
Division of Biological Sciences, University of Edinburgh, Scotland, U.K.
Exp Eye Res. 1993 Nov;57(5):527-37. doi: 10.1006/exer.1993.1157.
We have shown that cultured day-old chick lens epithelial cells undergo changes in crystallin expression during lens fibre (lentoid body) differentiation and ageing in serial subculture which are similar to those found in the adult lens in vivo. Here we have maintained neural retina cells, which transdifferentiate in vitro, for 250 days in serial subculture, in order to determine whether the tissue of origin affects the sequence of changes in crystallin expression and capacity for lentoid body formation both during fibre formation in primary culture and ageing in vitro. Alpha and beta-crystallins were detectable before delta-crystallin in primary cultures of both day-old chick lens epithelium and neural retina from 8-day embryos, but while beta 2 (26 kDa) was detected in pre-lentoid lens epithelial cultures it was not detected until after lentoids formed in neural retina cultures. The relative proportions of the alpha- and beta-crystallin polypeptides were similar in lentoid-rich lens epithelium and neural retina cultures, and both cultures underwent similar changes in serial subculture: a loss of lentoid forming capacity, an early preferential loss of delta-crystallin expression followed by a failure to accumulate first alpha- and then beta-crystallins. The order in which the beta-crystallin polypeptides were lost differed between the cultures. There is evidence for rapid turnover of alpha- and beta-crystallins while actin is the major component expressed in both types of aged cultures. Thus lens and retinal cells show some initial differences in the sequence of crystallin expression in primary cultures and in the eventual characteristics of aged cultures, but during the period beginning with lentoid formation and ending with the onset of senescence, lens cells from either source follow a broadly similar programme of ageing changes which are similar to those which occur during lens ageing in vivo.
我们已经表明，培养一天龄雏鸡晶状体上皮细胞在晶状体纤维（类晶状体）分化和连续传代培养老化过程中，晶状体蛋白表达会发生变化，这些变化与成年晶状体在体内所发现的变化相似。在此，我们对体外转分化的神经视网膜细胞进行了250天的连续传代培养，以确定组织来源是否会影响晶状体蛋白表达变化的顺序以及在原代培养纤维形成和体外老化过程中形成类晶状体的能力。在一天龄雏鸡晶状体上皮和8天胚胎的神经视网膜原代培养中，δ-晶状体蛋白之前可检测到α-和β-晶状体蛋白，但在类晶状体前的晶状体上皮培养中可检测到β2（26 kDa），而在神经视网膜培养中直到类晶状体形成后才检测到。富含类晶状体的晶状体上皮和神经视网膜培养中α-和β-晶状体蛋白多肽的相对比例相似，并且两种培养在连续传代中经历了相似的变化：类晶状体形成能力丧失，δ-晶状体蛋白表达早期优先丧失，随后无法积累α-晶状体蛋白，然后是β-晶状体蛋白。两种培养中β-晶状体蛋白多肽丧失的顺序不同。有证据表明α-和β-晶状体蛋白周转迅速，而肌动蛋白是两种老化培养中表达的主要成分。因此，晶状体和视网膜细胞在原代培养中晶状体蛋白表达顺序以及老化培养的最终特征方面存在一些初始差异，但在从类晶状体形成开始到衰老开始的这段时间内，来自任何一种来源的晶状体细胞都遵循大致相似的老化变化程序，这与体内晶状体老化过程中发生的变化相似。
