Functional interplay of transcriptional activators in the regulation of the cytoprotective human CYP2J2 gene

人细胞色素P450 2J2在多种组织中均有表达。这种酶作用于多不饱和脂肪酸，形成环氧化物，控制离子流量、血管大小和炎症，还帮助细胞在缺氧和其他压力的破坏作用下生存下来。因此，无论是在正常细胞还是损伤细胞中，细胞色素P450-2都具有重要的作用。增加细胞内CYP2J2的含量在防御损伤中可能是非常有价值的。然而，直到最近，还没有治疗方法能够做到这一点，但我们现在知道，具有重要生物学意义的维生素A衍生物全反式维甲酸(ATRA)可以增加细胞内的CYP2J2。在这个项目中，我们将在这一新发现的基础上开发增加组织中CYP2J2的治疗方法。大约10%的人有一种变异的CYP2J2基因，它与普通形式的基因有一个核苷酸的差异。这种多态变异会降低CYP2J2酶的数量，增加心血管风险。我们发现，这种多态位于基因的关键控制区，影响基因对转录因子的反应。本项目将详细研究与该控制区结合的转录因子对CYP2J2基因及其自然产生的变体的调控。我们还将测试该基因的多态版本对压力刺激和ATRA等增加细胞中野生型基因数量的治疗有何反应。研究人类基因调控是困难的，因为我们不能轻易地测量它们在个体中的水平。因此，我们将制造转基因小鼠来研究人类CYP2J2的调控，并将测试我们在细胞中设计的治疗方法是否在体内也有效。这些研究将帮助我们设计药物策略来增加细胞内的CYP2J2。通过维持CYP2J2的有益效果，并了解这些变化是如何在变体中发生变化的，该项目的一个重要成果可能是心血管疾病的新疗法。

Human cytochrome P450 2J2 (CYP2J2) is expressed in many tissues. This enzyme acts on polyunsaturated fatty acids to form epoxides that control ion fluxes, the size of blood vessels and inflammation, and also help cells to survive the damaging effects of oxygen deprivation and other stresses. So CYP2J2 has an important role in both normal and injured cells. Increasing the amount of CYP2J2 in cells may be extremely valuable in the defence against injury. Until recently, however, no treatments have been able to do this but we now know that the biologically important vitamin A derivative all-trans-retinoic acid (ATRA) can increase CYP2J2 in cells. In this project we will build on this novel finding to develop treatments that increase CYP2J2 in tissues. About 10% of people have a variant CYP2J2 gene that differs from the common form by one nucleotide. This polymorphic variant can decrease the amount of the CYP2J2 enzyme and increase cardiovascular risk. We ve found that this polymorphism is located in a critical control region of the gene and affects how the gene responds to transcription factors. The present project will study in detail the regulation of the CYP2J2 gene and its naturally occurring variant by transcription factors that bind to this control region. We will also test how the polymorphic version of the gene responds to stress stimuli and to treatments like ATRA that increase the amount of the wild-type gene in cells. Studying human gene regulation is difficult because we cannot easily measure their levels in individuals. So we will make transgenic mice to study human CYP2J2 regulation and will test whether the treatments we devise in cells also work in vivo. These studies will help us to design pharmacological strategies to increase CYP2J2 in cells. By maintaining the beneficial effects of CYP2J2, and understanding how these are altered in the variant, a significant outcome of the project could be a new treatment of cardiovascular disease.