Vascular Mechanisms of Hypertension-in-Pregnancy

项目概要/摘要 先兆子痫（PE）是一种以高血压（HTN-Preg）为特征的妊娠并发症， 胎儿宫内生长受限（IUGR），其发病机制尚不清楚，治疗方法有限。我们和其他人已经 显示：降低子宫灌注压（RUPP）和输注sFlt-1或TNF α在妊娠（Preg） 大鼠血管舒张减少，血管收缩（VC）和BP增加;然而，血管和子宫 目标不明确。正常妊娠涉及广泛的子宫胎盘和血管重塑， 金属蛋白酶（MMPs）和相关的A去整合素和金属蛋白酶（ADAM）家族维持足够的 组织重塑我们发现子宫胎盘和血管MMP-2和MMP-9降低， RUPP、sFlt-1和TNF α灌注的Preg大鼠中的MMP-1和MMP-7。我们还发现MMPs不仅 降解细胞外基质（ECM）蛋白，但也释放肽片段、生长因子和ET-1， 继而影响内皮细胞、血管平滑肌（VSM）和ECM（EVE），使得MMP-2和MMP-9 MMP-1和MMP-7是血管舒张剂（VD），而MMP-1和MMP-7是血管收缩剂（VC）。此外，为了寻找上游机制， 我们的数据表明，ADAM-17，一种脱落酶和TNF α转化酶， 在RUPP大鼠中增加，并且ADAM-17的升高导致MMP失衡，并增加循环TNF α， sFlt-1、VC和BP。这些新的发现使我们提出了新的假设，即VD/VC的破坏 MMP平衡是受损的EVT依赖性血管通路和HTN-Preg的主要机制。增加 ADAM-17活性触发MMP平衡的破坏。因此，纠正MMP失衡， 上调VD MMP-2和-9或下调VC MMP-1和-7，或降低上游ADAM-17 活性应改善EVE依赖性血管通路和HTN-Preg。将对Preg进行研究 大鼠; HTN-Preg的RUPP、sFlt-1和TNF α输注的大鼠模型;用MMP-2和MMP-9抑制剂处理的Preg大鼠， 中和抗体或siRNA或与ADAM-17、MMP-1或MMP-7;和MMP-2、MMP-9和MMP-7 KO小鼠。机械论 整个动物、子宫胎盘、微血管和分子水平的研究将提供深入的分析 将ADAM-17和MMP失衡与受损的EVT依赖性血管通路联系起来的机制， HTN-预浸料具体的目的是检验以下假设：1）VD/VC MMP平衡的破坏， 妊娠足以损害依赖于EVT的血管通路并引起HTN-Preg。2)增加 ADAM-17活性是触发VD/VC MMP平衡破坏的上游机制， 受损的EV依赖性血管通路和HTN-Preg. 3)基质金属蛋白酶失衡的干预性纠正 ADAM-17活性是改善EV依赖性血管通路和HTN-Preg的中心靶点。这些 研究应该提供对MMP失衡和ADAM-17在HTN-妊娠中的作用的更好理解， 强调纠正MMP失衡和ADAM-17活性在PE管理中的潜在有用性。

Project Summary/Abstract Preeclampsia (PE) is a complication of pregnancy characterized by hypertension (HTN-Preg) and intrauterine growth restriction (IUGR), with unclear mechanism and limited remedies. We and others have shown that: reduction in uterine perfusion pressure (RUPP) and infusion of sFlt-1 or TNF in pregnant (Preg) rats reduce vascular relaxation and increase vasoconstriction (VC) and BP; however, the vascular and uterine targets are unclear. Normal pregnancy involves extensive uteroplacental and vascular remodeling, and matrix metalloproteinases (MMPs) and related A Disintegrin And Metalloprotease (ADAM) family maintain adequate tissue remodeling. We have found decreases in uteroplacental and vascular MMP-2 and -9, and increases in MMP-1 and -7 in RUPP, and sFlt-1 and TNF infused Preg rats. We have also discovered that MMPs not only degrade extracellular matrix (ECM) proteins, but also release peptide fragments, growth factors and ET-1 and in turn affect the Endothelium, Vascular smooth muscle (VSM) and ECM (EVE), such that MMP-2 and -9 are vasodilators (VD) while MMP-1 and -7 are vasoconstrictors (VC). Also, in search for the upstream mechanisms that trigger the changes in MMPs, our data suggest that ADAM-17, a sheddase and TNF converting enzyme, is increased in RUPP rats, and elevation of ADAM-17 causes MMP imbalance, and increases circulating TNF and sFlt-1, VC and BP in Preg rats. These new findings led us to the novel hypothesis that disruption of VD/VC MMP balance is a major mechanism of impaired EVE-dependent vascular pathways and HTN-Preg. Increased ADAM-17 activity triggers disruption of MMP balance. Consequently, correcting MMP imbalance by upregulating VD MMP-2 and -9 or downregulating VC MMP-1 and -7, or reducing the upstream ADAM-17 activity should improve EVE-dependent vascular pathways and HTN-Preg. Studies will be performed on Preg rats; RUPP, sFlt-1 and TNF-infused rat models of HTN-Preg; Preg rats treated with MMP-2 and -9 inhibitors, neutralizing antibody or siRNA or with ADAM-17, MMP-1 or -7; and MMP-2, -9 and -7 KO mice. Mechanistic studies at the whole animal, uteroplacental, microvascular and molecular levels will provide in-depth analysis of the mechanisms linking ADAM-17 and MMP imbalance to impaired EVE-dependent vascular pathways and HTN-Preg. The specific aims are to test the hypotheses that: 1) Disruption of VD/VC MMP balance during pregnancy is sufficient to impair EVE-dependent vascular pathways and cause HTN-Preg. 2) Increased ADAM-17 activity is an upstream mechanism that triggers disruption of VD/VC MMP balance, leading to impaired EVE-dependent vascular pathways and HTN-Preg. 3) Interventional correction of MMP imbalance and ADAM-17 activity is a central target to improve EVE-dependent vascular pathways and HTN-Preg. These studies should provide a better understanding of the role of MMP imbalance and ADAM-17 in HTN-Preg, and highlight potential usefulness of correcting MMP imbalance and ADAM-17 activity in the management of PE.