Growth factor receptor gene and protein expressions in the human lens
Growth factor receptor gene and protein expressions in the human lens
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DOI：
10.1016/s0047-6374(99)00111-6
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发表时间：
2000-02-15
影响因子：
5.3
通讯作者：
Bhuyan, KC
中科院分区：
文献类型：
--
作者：
Bhuyan, DK;Reddy, PG;Bhuyan, KC
本研究采用半定量逆转录聚合酶链式反应(RT-PCR)技术，对0.5~72岁正常人晶状体表皮生长因子受体(EGFR)、碱性成纤维细胞生长因子受体(FGFR-2)和胰岛素样生长因子受体(IGFR-1)基因进行了鉴定。晶状体中EGFR基因表达的调节不随年龄的增长而改变，FGFR-2和IGFR-1基因的表达也保持不变，直到53岁。然而，FGFR-2和IGFR-1基因的表达在60岁以上的年龄有所下降。免疫印迹法检测40~72岁大鼠晶状体上皮细胞膜中EGFR、FGFR-2和IGFR-1蛋白的表达。晶状体纤维细胞膜中未检测到EGFR蛋白表达，FGFR-2和IGFR-1蛋白表达水平明显低于上皮细胞膜。这些受体蛋白在晶状体纤维细胞膜中的低水平表明，它们可能在维持这些独特的透明细胞的分化功能方面发挥作用。值得注意的是，随着EGFR年龄的增加，晶状体上皮细胞膜中FGFR-2蛋白水平增加，48岁及以上出现一些降解产物，60岁及以上则出现FGFR-2蛋白增加。这似乎是晶状体对老化过程的一种补偿性保护反应，通过在赤道地区的萌发区增殖和分化其上皮细胞成新的纤维细胞，使其终生继续正常生长。这些结果为进一步研究生长因子受体基因和蛋白在晶状体老化和老年性白内障进展机制中的调控作用奠定了基础。(C)2000爱思唯尔爱尔兰科学有限公司。保留所有权利。
In this study the mRNAs encoding epidermal:growth factor receptor (EGFR), basic fibroblast growth factor receptor (FGFR-2) and insulin-like growth factor receptor (IGFR-1) genes of the human normal lenses at ages varying from 0.5 to 72 years, were identified by semiquantitative reverse transcript ase-polymerase chain react ion (RT-PCR). Regulation of EGFR gene expression in the lens did not change with aging, and of FGFR-2 and IGFR-1 genes also remained unaltered up to age 53 years.-However, expressions of FGFR-2 and IGFR-1 genes were decreased at ages above 60 years. EGFR, FGFR-2 and IGFR-1 proteins were detected by immunoblot analysis in the epithetial cell membranes of lens at age varying from 40 to 72 years. There was no detectable amount of EGFR protein in fiber cell membranes of the lens, and the levels of FGFR-2 and IGFR-1 proteins were much lower than those in the epithelial cell membranes. The low levels of these receptor proteins in the fiber cell membranes of lens, suggest their possible role in keeping the differentiated function of these unique transparent cells. The findings of the increased protein levels with age of EGFR with the appearance of some degradation products at age 48 years and higher, and the increased FGFR-2 protein at age 60 years and higher in the epithelial cell membranes of lens, were of interest. It appears that this could be a compensatory protective response of the lens to aging process for lifelong continuation of normal growth by proliferation and differentiation of its epithelial cells into new fiber cells in-the germinative zone at the equatorial region. Thus, these results could provide a basis for further studies on growth factor receptor gene and protein regulations in the mechanism of lens aging and progression of age-related human cataract. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.