Expression of heme oxygenase‐1 is repressed by interferon‐γ and induced by hypoxia in human retinal pigment epithelial cells
Tóm tắt
The retinal pigment epithelium (RPE) is essential for maintenance of photoreceptors and normally functions under conditions enriched with reactive oxygen species. RPE therefore expresses various defense enzymes against oxidative stress, including heme oxygenase‐1 (HO‐1). HO‐1 catalyzes heme breakdown to release iron, carbon monoxide, and biliverdin, which is reduced to bilirubin, a potent radical scavenger. HO‐1 expression is induced by various environmental factors, which has been established as a defense mechanism. To explore the hypothesis that the expression level of HO‐1 is reduced in those RPE cells under certain conditions, we analyzed the effects of interferon‐γ and hypoxia, each of which represses the expression of HO‐1 mRNA in other types of human cells. Expression levels of HO‐1 mRNA were reduced by interferon‐γ in two human RPE cell lines, D407 and ARPE‐19, which was consistently associated with the induction of mRNA for Bach1, a transcriptional repressor for the
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Tài liệu tham khảo
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