Optogenetic control of vascular function during pregnancy

胎儿宫内生长受限(IUGR)会增加死产和新生儿死亡的风险。胎儿宫内发育迟缓的不良影响远远超出围产期，增加了晚年患心血管疾病等疾病的风险。血管对妊娠的适应性受损是导致IUGR的主要因素。为了了解子宫血管受损对母婴健康的影响，我们建议使用光遗传学技术来操纵活体动物的子宫血流。光遗传学是一种创新技术，基因修饰细胞表达光激活的微生物视蛋白(如通道视紫红质-2，ChR2)，然后在体内被光选择性地刺激。我们的目标是利用光遗传学开发一种新颖、可靠和生理上相关的IUGR小鼠模型。为了实现这一目标，我们提出了两个综合的科学目标。在目的1中，我们将确定体外光刺激对妊娠肌特异性ChR2转基因小鼠子宫动脉功能的影响。目标2将解决光刺激在体内收缩子宫动脉的能力，减少子宫动脉的血流量并产生IUGR。目前用于减少子宫血流量的小鼠模型需要结扎子宫动脉，这会导致胎儿死亡率高、重复性低等不良后果。我们的光生IUGR模型将更好地控制血流操纵的程度，增强实验之间的重复性，改善刺激的选择性，并降低胎儿死亡率。该项目将首次将光遗传学应用于活体子宫血管功能的研究。重要的是，我们的建议可以为将光遗传学应用于体内其他血管床的研究提供基础。

Intrauterine growth restriction (IUGR) increases the risk of stillbirth and neonatal death. The adverse effects of being born IUGR extend well beyond the perinatal period, increasing the risk of cardiovascular disease, among others, in later life. Impaired vascular adaptation to pregnancy is a predominant contributor to IUGR. To understand the effects of impaired uterine vasculature on maternal and infant health, we propose using optogenetics technology for manipulating uterine blood flow in live animals. Optogenetics is an innovative technique in which genetically modified cells express light-activated microbial opsins (e.g., channelrhodopsin- 2, ChR2), which can then be selectively stimulated by light in vivo. Our goal is to develop a novel, reliable and physiologically relevant murine model of IUGR using optogenetics. To address this goal, we propose to conduct two integrated scientific aims. In Aim 1, we will determine the effect of in vitro light stimulation on uterine artery function in pregnant smooth muscle specific ChR2 transgenic mice. Aim 2 will address the capacity for light stimulation to constrict the uterine artery in vivo, reducing uterine artery blood flow and producing IUGR. Current murine models for reducing uterine blood flow require uterine artery ligations, which have undesirable consequences such as high rate of fetal death and low reproducibility. Our optogenetic IUGR model will provide better control of the degree of blood flow manipulation, enhanced reproducibility among experiments, improved selectivity of the stimulation, and reduced fetal mortality. This project will be the first to apply optogenetics to the study of uterine vascular function in vivo. Importantly, our proposal can provide the foundation for applying optogenetics to the study of other vascular beds in vivo.