Role of FKBP12/12.6 in Endothelial Function

说明(申请人提供)：免疫抑制药物可降低移植后器官排斥反应的发生率，但这些药物会导致内皮功能障碍和高血压。我们的长期目标是阐明免疫抑制剂雷帕霉素和FK506降低一氧化氮(NO)和升高血压的机制，以便未来能够开发出不会促进高血压和心血管疾病的药物。我们推测，这些作用是由于FKBP12/12.6从细胞内钙释放通道中移除，导致内皮细胞基础钙水平升高和内皮型一氧化氮合酶(ENOS)磷酸化所致。为了验证这一假设，我们将：1)确定FKBP12/12.6缺失对细胞内钙稳态的影响，2)确定cPKC在eNOS磷酸化、NO产生和FKBP12/12.6改变后血压升高中的作用，以及3)评估FKBP12/12.6在内皮功能和血压调节中的作用。我们将使用FKBP12/12.6的药理和/或遗传干扰的组合，并测量其对血压、内皮依赖性扩张、NO产生、eNOS和PKC表达及磷酸化的影响。我们还将测量内皮细胞中FKBP12/12.6的缺失如何改变细胞内钙稳态，包括细胞内钙动员的大小、持续时间和位置的变化。抑制免疫系统的药物在器官移植后非常重要，但这些药物可能会导致高血压。我们的研究将使用各种转基因小鼠和技术来了解这一过程的机制，希望开发出未来不会对心血管产生负面影响的免疫抑制药物。

DESCRIPTION (provided by applicant): Immunosuppressive drugs reduce the incidence of organ rejection following transplantation, however these drugs can cause endothelial dysfunction and hypertension. Our long-term goal is to elucidate the mechanisms by which the immunosuppressive drugs rapamycin and FK506 decrease nitric oxide (NO) and increase blood pressure so that future drugs can be developed that do not promote hypertension and cardiovascular disease. We hypothesize that these effects arise from removal of FKBP12/12.6 from intracellular calcium release channels resulting in increased basal endothelial cell calcium levels and phosphorylation of endothelial NO synthase (eNOS). To test this hypothesis we will: 1) Determine the effects of FKBP12/12.6 depletion on intracellular calcium homeostasis, 2) Determine the role of cPKC in eNOS phosphorylation, NO production, and blood pressure elevation following alterations of FKBP12/12.6, and 3) Assess the role of FKBP12/12.6 in endothelial function and blood pressure regulation. We will use a combination of pharmacologic and/or genetic perturbations of FKBP12/12.6 and measure the effects on blood pressure, endothelium-dependent dilation, NO production, and eNOS and PKC expression and phosphorylation. We will also measure how FKBP12/12.6 depletion in endothelial cells alters intracellular calcium homeostasis including changes in the magnitude, duration, and location of intracellular calcium mobilization. Drugs that suppress the immune system are extremely important following organ transplantation, however these drugs can cause high blood pressure. Our research will use various genetically altered mice and techniques to understand the mechanisms of how this happens in hopes of developing future immunosuppressive drugs that will not have negative cardiovascular side effects.