Purchase this article with an account.
Kiyoshi Akeo, Tomoo Funayama, Yasuhiko Kobayashi, Yoko Akeo; Expression of Glutathione Peroxidase, p53, Bcl-2, and BAX Genes in Gamma-Irradiated Human Retinal Vascular Endothelial Cells. Invest. Ophthalmol. Vis. Sci. 2011;52(14):514.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Damaged retinal endothelial cells (RE) are characteristic senile macular degeneration and diabetic retinopathy pathogenesis. A retrospective study on macular degeneration treatment using gamma knife radiosurgery (GKR) reported that after treatment with a single shot of 12 Gy. However, further studies were required to better define the role of GKR in the treatment of macular degeneration . Glutathione peroxidase (GPX) is a lipid peroxide-scavenging enzyme with concomitant glutathione oxidation . Gamma irradiation is known to result in a dose-dependent decline in GPX activity in the skin of mice . Faucher previously measured the expression of pro-apoptotic BAX and anti-apoptotic Bcl-2 genes in human endothelial-like cell -lines overexpressing GPX . We found that gamma irradiation prevented programmed cell death regulated by the p53 and Bcl-2 genes in organ -cultured ciliary bodies. We applied gamma rays to induce oxidative stress, which influenced GPX expression in the RE cells; further, we measured the expression GPX by a quantitative real-time-reverse-transcriptase polymerase chain reaction (RT-PCR) using the LightCycler® system. We investigated how gamma irradiation influenced GPX and its prevention of phospholipid damage in RE cell membrane, and how the expression of GPX was related to the expression of p53, Bcl-2, and BAX genes regulating programmed cell death.
Human RE cells in vitro were exposed to 20Gy gamma ray radiation (60Co). We collected RE cells after 0, 4, 8, 24 hrs of irradiation, extracted total cellular RNA, and then synthesized cDNA. The cDNA of GPX, p53, Bcl-2, BAX, and 18S RNA were RT-PCR- amplified using designed primers. After mixing the cDNA, the primers, and SYBR green®, the expression of 18S RNA and GPX was measured using the LightCycler® system.
Gamma irradiation significantly increased the expression of GPX and p53genes in RE cells. The increase in p53 expression was significantly more than that in GPX expression. Furthermore, gamma irradiation increased the expression of BAX genes more significantly than that of Bcl-2 genes.
Gamma irradiation induced programmed cell death by the expression of p53 genes promoted by pro-apoptotic BAX genes, competing with anti-apoptotic Bcl-2 genes. The increase in GPX indicated a defense mechanism against gamma irradiation induced lipid peroxidation in RE cells.
This PDF is available to Subscribers Only