Low birth weight, uterine infection, and nitric oxide

描述(由申请人提供)：泌尿生殖系统感染和宿主因素通常与低出生体重有关，特别是在少数族裔人口中。大多数病原体，包括大肠杆菌，都会形成独特的毒力机制来定植和入侵泌尿生殖道。细菌粘附素，如E-COL的DR菌毛，与宿主组织受体相互作用，从而导致向上感染和相关并发症。一氧化氮(NO)是一种气体分子，具有多种功能，包括调节感染和免疫功能，据报道由子宫胎盘组织产生。这个项目的目标是评估NO是否通过调节细菌侵入细胞来调节子宫感染的严重程度。我们推测，NO系统调节子宫胎盘细菌受体，衰变加速因子(DAF)，从而调节细菌侵袭。我们认为，这种新的机制可以在感染的严重性和围产期的发病率，如低出生体重发挥作用。这些假设将通过追求三个具体目标来检验。具体目标1将确定NO是否抑制DR E线圈附着和内化到上皮细胞，以及这是否通过抑制DAF表达而发生。子目标1.1将描述子宫上皮细胞系、石川细胞、RL-95细胞和HEC-1细胞中的NO产生、NO合成酶(NOS)酶。如果操纵这些细胞中的NO合成会改变DR E线圈的附着和内化，则子目标1.2将检验这一假说。子目标1.3将检验上皮细胞DAF蛋白和信使核糖核酸含量受NO系统调控的假设。具体目标2将确定，在实验性宫内感染中，通过改变子宫DAF含量和血管系统，调节大鼠体内NO合成将改变感染的严重程度。子目标2.1将检验这样一个假设，即子宫胎盘组织中的DR*E线圈或B组链球菌(GBS)感染随着NO合成的增加而减少，随着NO合成的抑制而增加。次级目标2.2将检验子宫胎盘和血管组织中DAF含量的变化与NO合成的变化有关的假设。具体目标3将检查抑制NO合成和实验性宫内DR E线圈或GBS感染是否会导致大鼠胎儿生长受限，如果是的话，是否没有供体可以逆转胎儿生长受限。分目标3.1将检验这样一种假设，即抑制NO合成与宫内DR E线圈或GBS感染相结合，对胎儿和胎盘生长具有协同有害影响。子目标3.2将检验这样一个假设，即没有供体可以逆转子宫胎盘和血管组织以及胎儿生长受限中DAF表达的增加。

DESCRIPTION (provided by applicant): Urogenital infections and host factors are often associated with low birth weight, especially in minority populations. Most pathogens, including Escherichia coli, develop unique virulence mechanisms to colonize and invade the urogenital tract. Bacterial adhesins such as Dr fimbriae of E col interact with host tissue receptors allowing ascending infection and associated complications. Nitric oxide (NO), a gaseous molecule with versatile functions including the modulation of infection and immunity, is reported to be produced by uteroplacental tissues. The goal of this project is to assess if NO modulates severity of uterine infection through the regulation of bacterial invasion into cells. We hypothesize that the NO system regulates the uteroplacental bacterial receptor, decay accelerating factor (DAF), and therefore bacterial invasion. We propose that this novel mechanism could play a role in severity of infection and perinatal morbidities such as low birth weight. These hypotheses will be tested by pursuing three specific aims. Specific Aim 1 will determine whether NO inhibits Dr+ E coil attachment and internalization into epithelial cells and whether this occurs through suppression of DAF expression. Sub-aim 1.1 will characterize NO production, NO synthase (NOS) enzymes in uterine epithelial cell lines, Ishikawa, RL-95 and HEC-1 cells. Sub-aim 1.2 will test the hypothesis if manipulation of NO synthesis in these cells will alter Dr +E coil attachment and internalization. Sub-aim 1.3 will test the hypothesis that the epithelial cell DAF protein and mRNA contents are regulated by NO system. Specific Aim 2 will establish that modulation of NO synthesis in rats will alter severity of infection through the changes in DAF content of the uterus and vasculature in experimental intrauterine infection. Sub-aim 2.1 will test the hypothesis that Dr* E coil or group B streptococcus (GBS) infection in uteroplacental tissues is reduced with increases in NO synthesis and is increased with the inhibition of NO synthesis. Sub-aim 2.2 will test the hypothesis that changes in DAF content of uteroplacental and vascular tissues are related to changes in NO synthesis. Specific Aim 3 will examine if inhibition of NO synthesis and experimental intrauterine Dr E coil or GBS infection results in fetal growth restriction in rats, and if so, whether NO donor can reverse the fetal growth restriction. Sub-aim 3.1 will test the hypothesis that inhibition of NO synthesis combined with intrauterine Dr+E coil or GBS infection has synergistic detrimental effects on fetal and placental growth. Sub aim 3.2 will test the hypothesis that NO donor can reverse the increases in DAF expression in uteroplacental and vascular tissues and in fetal growth restriction.