Vascular Mechanisms of Hypertension-in-Pregnancy

项目摘要/摘要 子痫前期(PE)是妊娠期的并发症，以高血压(HTN-Preg)和 宫内生长受限(IUGR)，机制不明，治疗有限。我们和其他人有 结果显示：降低子宫灌注压(RUPP)和在妊娠期间输注sFlt-1或肿瘤坏死因子(PREG) 大鼠血管舒张性降低，血管收缩(VC)和血压升高；而血管和子宫 目标尚不清楚。正常妊娠涉及广泛的子宫胎盘和血管重构，以及基质 金属蛋白酶(MMPs)及相关的去整合素和金属蛋白酶(ADAM)家族维持充足 组织重塑。我们发现子宫胎盘和血管中的基质金属蛋白酶-2和-9的表达减少，而子宫-胎盘和血管中的基质金属蛋白酶-2和-9的表达增加。 RUPP中MMP1和MMP7，sFlt-1和肿瘤坏死因子注入PREG大鼠。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和 进而影响血管内皮细胞、血管平滑肌(VSM)和细胞外基质(EVE)，从而使基质金属蛋白酶-2和-9 血管扩张剂(VD)，而基质金属蛋白酶-1和-7是血管收缩药(VC)。此外，在寻找上游机制时， 我们的数据表明，脱落酶和肿瘤坏死因子转换酶ADAM-17， 在RUPP大鼠中，AS升高，ADAM-17升高导致基质金属蛋白酶失衡，并增加循环中肿瘤坏死因子 妊娠期大鼠sFlt-1、VC、BP。这些新的发现引导我们提出了一个新的假设，即VD/VC的中断 基质金属蛋白酶平衡是EVE依赖的血管通路和HTN-Preg受损的主要机制。增加了 ADAM-17的活性触发了基质金属蛋白酶平衡的破坏。因此，通过以下方式纠正基质金属蛋白酶失衡 上调血管内皮细胞基质金属蛋白酶-2和-9或下调血管内皮细胞基质金属蛋白酶-1和-7，或减少上游的ADAM-17 活动应该改善EVE依赖的血管通路和HTN-Preg。研究将在PREG上进行 RUPP、sFlt-1和肿瘤坏死因子注射大鼠hTN-Preg模型，应用MMP2和-9抑制剂治疗的大鼠， 中和抗体或siRNA或与ADAM-17、MMP1或-7，以及MMP2、MMP9和MMP7 KO小鼠。机械论 对整个动物、子宫胎盘、微血管和分子水平的研究将提供深入的分析 ADAM-17和基质金属蛋白酶失衡与EVE依赖的血管通路受损和 HTN-Preg.具体目的是验证以下假设：1)VD/VC的基质金属蛋白酶平衡在 怀孕足以损害EVE依赖的血管通路，并导致HTN-Preg。2)增加 ADAM-17活性是一种上游机制，可触发VD/VC基质金属蛋白酶平衡的破坏，导致 EVE依赖的血管通路受损和HTN-Preg。3)基质金属蛋白酶失衡的介入性矫正 而ADAM-17活性是改善EVE依赖的血管通路和HTN-Preg的中心靶点。这些 研究应该更好地了解基质金属蛋白酶失衡和ADAM-17在HTN-Preg中的作用，以及 强调纠正基质金属蛋白酶失衡和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.