Patek C E, Clayton R M
Department of Genetics, University of Edinburgh, U.K.
Exp Eye Res. 1990 Apr;50(4):345-54. doi: 10.1016/0014-4835(90)90135-h.
We have reported that 1-day-old post-hatch chick lens epithelial cells lose the capacity for lentoid body formation and delta-crystallin expression during long-term serial subculture, although they continue to synthesize, but not to accumulate, alpha- and beta-crystallins, even in cells with a transformed phenotype. Here we present evidence that dedifferentiation may reflect an age-related change in the capacity for response to regulatory signals. We have tested the capacity of these cells in serial subcultures to respond to agencies which affect lens cell growth and differentiation in primary culture: retinoic acid (RA), insulin, cAMP and bovine retinal extract (BRE). Secondary cultures responded only to RA and BRE, by an increase in lentoid formation and by alpha- and beta-accumulation, while RA also restored delta-crystallin expression. Later cultures showed no such responses. The results suggest that the process of lens cell dedifferentiation may, at first, be reversible but later becomes irreversible, despite the continuing persistence of low levels of crystallin expression.
我们曾报道，孵化后1日龄雏鸡晶状体上皮细胞在长期连续传代培养过程中丧失了形成类晶体体和表达δ-晶体蛋白的能力，尽管它们继续合成α-和β-晶体蛋白，但不进行积累，即使在具有转化表型的细胞中也是如此。在此，我们提供证据表明去分化可能反映了对调节信号反应能力的年龄相关变化。我们测试了这些连续传代培养细胞对影响原代培养中晶状体细胞生长和分化的因子的反应能力：视黄酸（RA）、胰岛素、环磷酸腺苷（cAMP）和牛视网膜提取物（BRE）。二代培养物仅对RA和BRE有反应，表现为类晶体形成增加以及α-和β-晶体蛋白积累，同时RA还恢复了δ-晶体蛋白的表达。后期培养物则无此类反应。结果表明，晶状体细胞去分化过程起初可能是可逆的，但后来变得不可逆，尽管晶体蛋白表达水平持续维持在较低水平。
