Promoter activity and regulation of the corneal CYP4B1 gene by hypoxia
Tóm tắt
Hypoxic injury to the ocular surface provokes an inflammatory response that is mediated, in part, by corneal epithelial‐derived 12‐hydroxyeicosanoids. Recent studies indicate that a cytochrome P450 (CYP) monooxygenase, identified as CYP4B1, is involved in the production of these eicosanoids which exhibit potent inflammatory and angiogenic properties. We have isolated and cloned a corneal epithelial CYP4B1 full‐length cDNA and demonstrated that the CYP4B1 mRNA is induced by hypoxia in vitro and in vivo. To further understand the molecular regulation that underlies the synthesis of these potent inflammatory eicosanoids in response to hypoxic injury, we isolated and cloned the CYP4B1 promoter region. GenomeWalker libraries constructed from rabbit corneal epithelial genomic DNA were used as templates for primary and nested PCR amplifications with gene‐ and adaptor‐specific primers. A 3.41‐kb DNA fragment of the 5′‐flanking region of the CYP4B1 promoter was isolated, cloned, sequenced, and analyzed by computer software for the presence of known
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