The (patho)physiological role(s) of CYP450-mediated mechanism(s) in the ophthalmic artery

虽然血管相关的危险因素在青光眼的发病机制中不是一个新概念，但细胞信号传导机制和蛋白质组变化的改变仍然是未知的。我们的初步研究表明，细胞色素P450（CYP 450）途径在介导眼动脉血管舒张反应中起着关键作用。因此，本研究的主要目的是通过解决三个主要假设来研究CYP 450介导的信号传导或其缺乏在眼微循环中的（病理）生理作用。迄今为止，CYP 450衍生的类花生酸的身份，表达和机制，以及脂质介质的主要代谢酶可溶性环氧化物水解酶（sEH）在眼血管张力和重塑调节中的潜在作用尚未确定。因此，第一个假设是，当暴露于青光眼相关风险因素和损伤时，sEH抑制将通过增强眼动脉中CYP 450衍生的类花生酸的生物利用度来赋予血管保护作用。本研究将确定CYP 450/sEH信号传导如何维持眼动脉完整性以及涉及哪些特定途径和/或介质。我们还表明，这个血管床具有固有的代偿机制，保持血管舒张时，信号通路受损。因此，待检验的第二个假设是眼动脉能够补偿并保持慢性缺乏CYP 450的接近正常的血管反应。这项研究将阐明潜在的蛋白质组，细胞和血管结构的适应过程，努力缓冲潜在的不利影响，由于缺乏CYP 450介导的信号转导。第三个假设是膳食补充ω-3脂肪酸（ω3-PUFA）可作为替代底物，预防由于长期缺乏CYP 450而导致的血管功能障碍。本研究的结果旨在揭示眼动脉中PUFA引起的代偿性分子谱的潜在变化。另一方面，我们也证明了缝隙连接与CYP 450协同工作，并且首次发现Kv1.6通道参与介导血管舒张反应。然而，在这条动脉中，关于缝隙连接蛋白和Kv1.6通道的互补机制的知识仍然存在巨大的空白。因此，最后的调查将阐明细胞间通讯网络的两个组件和潜在的改变，在他们的相互作用时，CYP 450/sEH是缺乏。总之，本研究将表征眼动脉中CYP 450介导机制的（病理）生理作用，这将促进未来改善青光眼眼部灌注的转化工作。

While the vascular-related risk factor is not a new concept in the pathogenesis of glaucoma, alterations in cell signalling mechanisms and proteome changes underlying perturbed retrobulbar microcirculation, particularly the ophthalmic artery, are still unknown. Our preliminary studies have demonstrated that the cytochrome P450 (CYP450) pathway plays a key role in mediating ophthalmic arterial vasodilatory responses. Therefore, the main aim of this study is to investigate the (patho)physiological roles of the CYP450-mediated signalling or its lack thereof, in the ophthalmic microcirculation by addressing three major hypotheses. To date, the identity, expression and mechanisms of CYP450-derived eicosanoids and potential role of the main metabolizing enzyme of lipid mediators, soluble epoxide hydrolase (sEH), in the regulation of ophthalmic vascular tone and remodelling are uncharacterized. Hence, the first hypothesis is sEH inhibition would confer vasoprotection when exposed to glaucoma-related risk factors and insults by enhancing the bioavailability of CYP450-derived eicosanoids in the ophthalmic artery. This investigation will determine how the CYP450/sEH signalling maintains ophthalmic arterial integrity and what specific pathway(s) and/or mediator(s) are involved. We also demonstrated that this vascular bed possesses inherent compensatory mechanisms that preserve vasodilation when a signalling pathway is impaired. Thus, the second hypothesis to be tested is the ophthalmic artery is able to compensate and retain near-normal vascular responses in chronic lack of CYP450. This investigation will elucidate the underlying proteome, cellular and vascular structural adaptation processes that strive to buffer potential detrimental effects due to the lack of CYP450-mediated signal transduction. The third hypothesis is dietary supplementation with omega-3 fatty acids (ω3-PUFAs) would act as alternative substrates and prevent vascular dysfunction attributed to the chronic lack of CYP450. The findings of this investigation are envisioned to unravel potential shift(s) in the compensatory molecular profiles attributed to PUFAs in the ophthalmic artery. On the other hand, we have also demonstrated that gap junctions work in concert with CYP450 and the Kv1.6 channel is found for the first time to be involved in mediating vasodilatory responses. However, there is still a huge gap in knowledge about the complementary mechanisms involving gap junctional connexins and Kv1.6 channel in this artery. Thus, the final investigation will elucidate the intercellular communication networks of both components and potential alterations in their interactome when CYP450/sEH is lacking. In gist, this study will characterize the (patho)physiological role(s) of CYP450-mediated mechanism(s) in the ophthalmic artery that will facilitate future translational efforts in improving ocular perfusion in glaucoma.