Endothelial Lipoxygenase Metabolites and Vascular Tone

内皮脂氧合酶代谢物和血管张力

基本信息

批准号：
8675910
负责人：
WILLIAM BRYSON CAMPBELL
金额：
$ 37.49万
依托单位：
MEDICAL COLLEGE OF WISCONSIN
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-06-01 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8675910
关键词：
Acetylcholine Acids Address Agonist Angiotensin II Angiotensins Apamin Arachidonate 15-Lipoxygenase Arachidonic Acids Arteries Binding Binding Sites Biochemical Biological Assay Blood Pressure Blood Vessels Calcium Cardiovascular Diseases Cell membrane Cells Cholesterol Contractile Proteins Coupled Diabetes Mellitus Eicosatrienoic Acid Endothelial Cells Endothelium Endothelium-Dependent Relaxing Factors Epoprostenol G-substrate GTP Binding GTP-Binding Proteins Goals Guanosine Triphosphate Health Heart failure Heterotrimeric GTP-Binding Proteins Hypertension Hypoxia Innovative Therapy Interleukins Knowledge Link Lipoxygenase Mediating Membrane Methods Molecular Molecular Mechanisms of Action Monomeric GTP-Binding Proteins Myocardial Ischemia Myosin Light Chains Nitric Oxide Nitric Oxide Synthase Norepinephrine Oryctolagus cuniculus Pathway interactions Potassium Potassium Channel Prostaglandin-Endoperoxide Synthase Proteins Regulation Relaxation Rho-associated kinase Role Signal Pathway Smooth Muscle Myocytes Testing Therapeutic Vascular Diseases Vasoconstrictor Agents Vasodilator Agents angiotensin hypertension blood pressure regulation constriction cyclooxygenase 2 endothelial dysfunction guanine nucleotide binding protein improved insight myosin phosphatase novel novel strategies novel therapeutic intervention patch clamp phospholipase inhibitor receptor relaxing factor vasoconstriction

项目摘要

DESCRIPTION (provided by applicant): Endothelial cells release nitric oxide, prostaglandin I2 and endothelium-derived hyperpolarizing factor (EDHF) that reduce vascular tone and counteract vasoconstriction. Ischemic heart disease, heart failure and hyperten- sion are associated with vasoconstriction that is attributed, in part, to reductions in endothelium-dependent di- lation. Therapeutic approaches restoring endothelial function represent promising new treatments for cardio- vascular diseases with a major impact on health. We have identified a 15-lipoxygenase (LO) metabolite of ara- chidonic acid, 11(R),12(S),15(S)-trihydroxy-eicosatrienoic acid (11,12,15-THETA), that acts as an EDHF. It relax arteries, in part, by activating apamin-sensitive, small conductance, calcium-activated potassium (SKCa) channels and hyperpolarizing smooth muscle cells (SMCs). It also acts by inhibition of RhoA activation. 11,12,15-THETA mediates a portion of the endothelium-dependent relaxations to acetylcholine (ACh), in- creases in flow and AA and opposes the action of vasoconstrictors. We will test the hypothesis that 11,12,15- THETA mediates relaxations to ACh and AA by a unique combination of mechanisms: (1) activating a hetero- trimeric guanine nucleotide binding protein (G protein) that opens SKCa channels resulting in hyperpolarization of SMCs and (2) inhibiting the activation of the small GTPase RhoA reducing the calcium sensitivity of contrac- tile proteins. These studies will indicate that 11,12,15-THETA is an EDHF and an endothelium-derived calcium (Ca) desensitizer. 11(R),12(S),15(S)-THETA increases GTP335S binding to rabbit arterial membranes implicat- ing a G protein-coupled binding site/receptor. Using biochemical and molecular methods, we will identify the G protein(s) that is coupled to 11,12,15-THETA action. Using patch clamp and bioassay methods, we will char- acterize the role of the G protein in the regulation of SKCa channel activity, hyperpolarization and dilation by 11,12,15-THETA. These studies will provide new insights into the molecular mechanism of action of 11,12,15- THETA and the regulation of vascular SKCa channel activity. Agonists such as norepinephrine and angiotensin promote constriction by activating the RhoA-Rho kinase cascade that sensitizes contractile proteins to Ca. 11,12,15-THETA decreases the formation of the active form of RhoA, RhoA-GTP. These studies will test the hypothesis that 11,12,15-THETA causes relaxation by inhibiting RhoA activation resulting in decreased Rho kinase activity increasing myosin light chain phosphatase activity and decreasing phosphorylated myosin light chain. These studies will access the effect of 11,12,15-THETA on RhoA activity in SMCs and arteries and de- termine the contribution of RhoA inhibition to the relaxations to 11,12,15-THETA. The role of a G protein in RhoA inhibition by 11,12,15-THETA will be determined. These studies will identify two new mechanisms of action for the endothelium-derived relaxing factor 11,12,15-THETA and provide a new therapeutic approach to enhancing endothelial function.

描述（由申请人提供）：内皮细胞释放一氧化氮，前列腺素I2和内皮衍生的超极化因子（EDHF），可降低血管张力和抵抗血管收缩。缺血性心脏病，心力衰竭和高血压与血管收缩有关，这部分归因于依赖内皮依赖性疾病的减少。恢复内皮功能的治疗方法代表了对心脏疾病的新疗法，对健康有重大影响。我们已经确定了15-脂氧酶（LO）的ara- chidonic酸代谢产物，11（r），12（s），15（s） - 三羟基 - 二十二酸酯酸（11,12,15-theta），可作为EDHF。它部分通过激活阿瓜蛋白敏感，小电导，钙激活的钾（SKCA）通道和超极化平滑肌细胞（SMC）来放松动脉。它也通过抑制RhoA激活来起作用。 11,12,15- theta介导一部分内皮依赖性松弛到乙酰胆碱（ACH），流动和AA中的折痕，并反对血管收缩剂的作用。 We will test the hypothesis that 11,12,15- THETA mediates relaxations to ACh and AA by a unique combination of mechanisms: (1) activating a hetero- trimeric guanine nucleotide binding protein (G protein) that opens SKCa channels resulting in hyperpolarization of SMCs and (2) inhibiting the activation of the small GTPase RhoA reducing the calcium sensitivity of构成蛋白质。这些研究将表明11,12,15-Theta是EDHF和内皮衍生的钙（CA）脱敏剂。 11（r），12（s），15（s）-Theta增加了与兔动脉膜结合的GTP335S，与G蛋白偶联的结合位点/受体有关。使用生化和分子方法，我们将识别G蛋白耦合到11,12,15-THETA作用。使用斑块夹和生物测定方法，我们将通过11,12,15-THETA来征服G蛋白在SKCA通道活性，超极化和扩张的调节中的作用。这些研究将提供有关11,12,15- theta和血管SKCA通道活性的分子作用机理的新见解。诸如去甲肾上腺素和血管紧张素之类的激动剂通过激活将收缩蛋白敏感的Rhoa-Rho激酶级联反应促进收缩。 11,12,15-Theta降低了Rhoa，Rhoa-GTP的活性形式的形成。这些研究将检验以下假设：11,12,15吨通过抑制RhoA激活导致松弛，从而导致Rho激酶活性降低，从而增加肌球蛋白轻链磷酸酶活性并降低磷酸化的肌球蛋白光链。这些研究将访问11,12,15-Theta对SMC和动脉中RhoA活性的影响，并终止RhoA抑制对松弛对11,12,15-Theta的贡献。将确定G蛋白在RhoA抑制11,12,15-THETA中的作用。这些研究将确定内皮衍生的放松因子11,12,15吨的两种新作用机理，并提供了增强内皮功能的新治疗方法。