Hara E, Takahashi K, Tominaga T, Kumabe T, Kayama T, Suzuki H, Fujita H, Yoshimoto T, Shirato K, Shibahara S
Department of Applied Physiology and Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan.
Biochem Biophys Res Commun. 1996 Jul 5;224(1):153-8. doi: 10.1006/bbrc.1996.0999.
Heme oxygenase-1, a key enzyme in heme catabolism, and inducible nitric oxide synthase (iNOS) are responsible for production of carbon monoxide and nitric oxide (NO), respectively. Expression of each enzyme has been shown to be modulated by heme and NO, raising a possibility for the coordinated regulation of the two enzymes. We therefore analyzed the expression levels of both mRNA in humans using brain tumors. Either heme oxygenase-1 or iNOS mRNA was expressed at higher levels in brain tumors compared to the brain tissue, but their expression levels were not apparently correlated. In the brain tumor cell lines, treatment with cytokines increased the expression of iNOS mRNA but not heme oxygenase-1 mRNA, whereas treatment with an NO donor increased the expression of heme oxygenase-1 mRNA but not iNOS mRNA. These results suggest the separate regulation of expression of both enzyme mRNA in humans.
血红素加氧酶-1是血红素分解代谢中的关键酶，诱导型一氧化氮合酶（iNOS）则分别负责一氧化碳和一氧化氮（NO）的生成。研究表明，每种酶的表达都受到血红素和NO的调节，这增加了两种酶协同调节的可能性。因此，我们利用脑肿瘤分析了人类中这两种mRNA的表达水平。与脑组织相比，脑肿瘤中血红素加氧酶-1或iNOS mRNA的表达水平均较高，但它们的表达水平并无明显相关性。在脑肿瘤细胞系中，细胞因子处理可增加iNOS mRNA的表达，但不增加血红素加氧酶-1 mRNA的表达，而NO供体处理则可增加血红素加氧酶-1 mRNA的表达，但不增加iNOS mRNA的表达。这些结果表明，人类中这两种酶mRNA的表达受到独立调节。
