Oxidant Stress Mechanisms in Preeclampsia

描述(申请人提供)：这项研究中要检验的最重要的假设是，中性粒细胞渗透引起的血管炎症对先兆子痫的病理生理学至关重要。中性粒细胞渗入血管系统可通过释放有毒化合物，如活性氧物种(ROS)、肿瘤坏死因子？和血栓素而引起炎症和血管收缩。在特定的目标1中，我们将确定中性粒细胞的母体血管渗透是否是先兆子痫的标志，并与血管炎症相关。收集妊娠患者的皮下脂肪、大网膜脂肪和胎盘组织，用免疫组织化学方法评估正常未妊娠、正常妊娠和先兆子痫妇女的血管表型，并确定中性粒细胞是否仅限于母室。我们将对组织进行CD66b(中性粒细胞标记物)、细胞间黏附分子-1(中性粒细胞内皮细胞黏附分子)、白介素8(一种强有力的中性粒细胞趋化因子)、核因子-β和环氧合酶-2(炎症标志物)、髓过氧化物酶(一种强有力的氧化酶)以及基质金属蛋白酶1和8的染色。这一目的观察到的血管病理的原位发现将推动AIMS 2-4的机制研究，这将探讨中性粒细胞诱导的血管炎症和血管收缩的机制。在特定的目标2中，我们将评估已经渗透到内膜间隙的中性粒细胞是否通过与人血管平滑肌细胞共培养而负责将炎症传递到血管平滑肌。我们将通过转染和细胞培养来确定中性粒细胞是否能够激活人血管平滑肌细胞(VSMC)中的核因子-β，并诱导COX-2、IL-8和血栓素的表达。在具体目标3中，我们将使用分离的大网膜血管和VSMC细胞培养的肌图系统来研究中性粒细胞引起血管收缩和/或增强血管对血管收缩药的反应性的细胞机制。在特定的目标4中，我们将确定中性粒细胞或中性粒细胞产品是否会导致与炎症相关的血管平滑肌基因的表观遗传学变化，从而可能对母亲的心血管功能产生不利的长期影响。候选基因的甲基化模式将通过亚硫酸氢盐DNA序列分析和COBRA(联合亚硫酸盐限制分析)评估正常妊娠妇女和先兆子痫妇女血管中的甲基化模式。我们还将确定中性粒细胞或中性粒细胞产物(ROS，TNF？)在培养的VSMC中，以类似的模式改变这些基因的甲基化状态。这一新的假设可能解释未来的健康问题，包括复发的子痫前期和未来的心血管疾病风险。 公共卫生相关性：先兆子痫是母婴发病率和死亡率的主要原因。这项研究将检验这一假设，即中性粒细胞浸润引起的血管炎症对先兆子痫的病理生理至关重要。这一假说包含了对恶性循环的分子解释，这种恶性循环加剧了子痫前期的血管炎症，并在母亲的血管系统中产生了表观遗传印记，可能使女性容易患上慢性心血管疾病。

DESCRIPTION (provided by applicant): The over-arching hypothesis to be tested in this research is that vascular inflammation due to neutrophil infiltration is critical to the pathophysiology of preeclampsia. Neutrophils infiltrating the vasculature could cause inflammation and vasoconstriction by release of toxic compounds, such as reactive oxygen species (ROS), TNF??and thromboxane. In Specific Aim 1, we will determine if maternal vascular infiltration by neutrophils is a hallmark of preeclampsia, and associated with vascular inflammation. Subcutaneous fat, omental fat and placental tissue from pregnant patients will be collected and evaluated by immunohisto chemistry to assess vascular phenotypes of normal nonpregnant, normal pregnant and preeclamptic women, and to determine if neutrophil infiltration is restricted to the maternal compartment. We will stain tissues for CD66b (a neutrophil marker), intercellular adhesion molecule-1 (an endothelial adhesion molecule for neutrophils), interleukin-8 (IL-8, a potent neutrophil chemokine), NF-?B and COX-2 (hallmarks of inflammation), myeloperoxidase (a potent oxidizing enzyme), and matrix metalloproteinases 1 and 8. The in situ findings of vascular pathology observed in this Aim will drive the mechanistic studies of Aims 2-4 which will examine mechanisms for neutrophil induced vascular inflammation and vasoconstriction. In Specific Aim 2, we will evaluate whether neutrophils that have infiltrated into the intimal space could be responsible for transmitting inflammation to the vascular smooth muscle by co-culturing neutrophils with human vascular smooth cells. We will use transfection and cell culture to determine if neutrophils can activate NF-?B and induce expression of COX-2, IL-8 and thromboxane in human vascular smooth muscle cells (VSMC). In Specific Aim 3, we will use a myograph system with isolated omental vessels and cell culture of VSMC to examine cellular mechanisms whereby neutrophils could cause vasoconstriction and/or enhance vessel reactivity to vasoconstrictors. In Specific Aim 4, we will determine if neutrophils or neutrophil products induce epigenetic changes in vascular smooth muscle genes related to inflammation, and thus, may program adverse long-term effects on maternal cardiovascular function. Methylation patterns of candidate genes will be evaluated in vessels from women with normal pregnancies and women with preeclampsia by bisulfite DNA sequence analysis and COBRA (Combined Bisulfite Restriction Analysis). We will also determine if neutrophils or neutrophil products (ROS, TNF?) alter the methylation status of these genes in a similar pattern in cultured VSMC. This novel hypothesis may explain future health issues, including recurrent preeclampsia and future risk of cardiovascular disease. PUBLIC HEALTH RELEVANCE: Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. This research will test the hypothesis that vascular inflammation due to neutrophil infiltration is critical to the pathophysiology of preeclampsia. This hypothesis encompasses molecular explanations for a vicious cycle that reinforces vascular inflammation in preeclampsia, and creates an epigenetic imprint in the maternal vascular system that may predispose women to chronic cardiovascular disease.