Fleming T P, Song Z, Andley U P
Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Invest Ophthalmol Vis Sci. 1998 Jul;39(8):1387-98.
Peptide growth factors including hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF) are mitogens for many cell types and may act as regulators of lens epithelial cell growth and differentiation. The present study was undertaken to investigate the expression of growth factor receptors and crystallin genes in the human lens epithelial cell line HLE B-3, created by infection with Adeno12-simian virus 40 (Ad12-SV40) hybrid virus.
Reverse transcriptase-polymerase chain reaction (RT-PCR) with gene-specific primers was used to detect transcripts, and Southern and western blot analyses were used for identification of gene products. Functional analysis of PDGF receptor was performed by measuring the effect of PDGF-BB on Ca2+ release, cell growth, and western blot analysis, by using an antiphosphotyrosine antibody.
Human lens epithelial B-3 cells expressed the growth factor receptors HGF-R, EGF-R, and PDGF-Rbeta, but not PDGF-Ralpha, and also expressed the oncogenes H-ras and raf and the growth inhibitor transforming growth factor-beta1. Stimulation of PDGF-Rbeta with PDGF-BB in HLE B-3 cells increased phosphorylation of the receptor, was associated with an increase in intracellular Ca2+ levels, and produced a small increase in cell growth. In addition, HLE B-3 cells expressed transcripts for alphaA-, alphaB-, and betaB2-crystallins, and expressed the corresponding proteins. The transcripts for alphaA-crystallin decreased markedly at higher passages.
The above findings suggest that the increased growth potential of human lens epithelial cells by Ad12-SV40 infection maintained certain lens-specific properties and response to PDGF.
包括肝细胞生长因子（HGF）、血小板衍生生长因子（PDGF）和表皮生长因子（EGF）在内的肽生长因子是多种细胞类型的有丝分裂原，可能作为晶状体上皮细胞生长和分化的调节因子。本研究旨在调查通过腺病毒12 - 猴病毒40（Ad12 - SV40）杂交病毒感染建立的人晶状体上皮细胞系HLE B - 3中生长因子受体和晶状体蛋白基因的表达。
使用基因特异性引物的逆转录聚合酶链反应（RT - PCR）检测转录本，Southern和western印迹分析用于鉴定基因产物。通过测量PDGF - BB对Ca2 +释放、细胞生长的影响以及使用抗磷酸酪氨酸抗体进行western印迹分析，对PDGF受体进行功能分析。
人晶状体上皮B - 3细胞表达生长因子受体HGF - R、EGF - R和PDGF - Rβ，但不表达PDGF - Rα，还表达癌基因H - ras和raf以及生长抑制因子转化生长因子 - β1。用PDGF - BB刺激HLE B - 3细胞中的PDGF - Rβ会增加受体的磷酸化，与细胞内Ca2 +水平升高相关，并使细胞生长略有增加。此外，HLE B - 3细胞表达αA -、αB -和βB2 -晶状体蛋白的转录本，并表达相应的蛋白质。αA -晶状体蛋白的转录本在较高传代时显著减少。
上述发现表明，Ad12 - SV40感染导致人晶状体上皮细胞生长潜力增加，同时维持了某些晶状体特异性特性以及对PDGF的反应。
