INVOLVEMENT OF CALCIUM-INDEPENDENT PHOSPHOLIPASE A2? IN HIGH GLUCOSE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们在此报道，钙非依赖性磷脂酶A2在高糖诱导的RhoA/Rho-Kinase/CPI-17激活和糖尿病相关的血管平滑肌过度收缩中起关键作用。首先，我们证明了高糖增加了VSMC中iPLA2蛋白的表达和酶活性。此外，iPLA2的激活先于高糖诱导的CPI-17的激活。其次，使用三种独立的方法(药物抑制、基因缺失和腺病毒介导的功能恢复)，我们证明了iPLA2在高糖诱导的CPI-17磷酸化中是必不可少的。第三，我们证明脂氧合酶，特别是15-脂氧合酶，选择性地参与高糖诱导和iPLA2？介导的CPI-17的磷酸化。第四，我们证明iPLA2是高糖诱导的RhoA和Rho-Kinase激活所必需的。有趣的是，我们发现PKC是高糖诱导的iPLA2蛋白上调所必需的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We report here that calcium-independent phospholipase A2¿ (iPLA2¿) plays a critical role in high glucose-induced RhoA/Rho-kinase/CPI-17 activation and diabetes-associated vascular smooth muscle hypercontractility. First, we show that high glucose increases iPLA2¿ protein expression and enzymatic activity in VSMC. Moreover, activation of iPLA2¿ precedes high glucose-induced CPI-17 activation. Second, using three independent approaches (pharmacological inhibition, genetic deletion, and adenoviral-mediated functional restoration), we illustrate that iPLA2¿ is essential for high glucose-induced CPI-17 phosphorylation. Third, we demonstrate that lipoxygenases, and particularly 15-lipoxygenases, are selectively involved in high glucose-induced and iPLA2¿-mediated CPI-17 phosphorylation. Fourth, we show that iPLA2¿ is required for high glucose-induced RhoA and Rho-kinase activation. Interestingly, we find that PKC is required for high glucose-induced iPLA2¿ protein upregulation.