FoxM1 regulates endothelial repair following lung vascular injury

描述（由申请人提供）：肺血管损伤后内皮完整性的恢复是血管稳态的一个知之甚少的方面。我们的长期目标是使用分子，细胞和体内方法来阐明血管损伤后内皮屏障修复的机制，并确定新的治疗靶点，以防止持续性肺血管损伤和与脓毒症诱导的急性肺损伤相关的微血管渗漏。FoxM 1是细胞增殖所必需的转录因子叉头盒（Fox）家族的成员。小鼠中的FoxM 1无效突变由于有丝分裂的不正确执行以及由此产生的心脏和肝脏中的多倍体细胞而导致胚胎死亡。我们将检验FoxM 1是肺血管损伤后内皮修复的关键决定因素的一般假设。我们的目的是确定FoxM 1在调节内皮细胞增殖和重新退火内皮连接，从而恢复肺血管损伤后的内皮完整性中的重要作用。这些研究将针对以下具体目标：1.探讨肺血管损伤后FoxM 1表达的调控机制。我们将剖析LPS诱导的肺血管损伤后介导FoxM 1诱导的肺微血管信号通路。我们将检验以下假设：肺血管损伤后内皮细胞-细胞接触丧失通过PI 3 K/Akt依赖性下调p27 Kip 1（细胞接触抑制的关键决定因素）诱导内皮细胞中FoxM 1表达。2.阐明FoxM 1调控内皮细胞增殖的分子机制。我们将表征FoxM 1缺陷型肺内皮细胞的细胞周期进展缺陷，并确定内皮细胞增殖所必需的基因FoxM 1转录网络。我们还将剖析FoxM 1调控p27 Kip 1的机制。3.确定FoxM 1在恢复内皮完整性机制中的作用。我们将讨论FoxM 1在肺血管损伤后重组内皮细胞-细胞连接中起重要作用的可能性。我们还将在具有内皮细胞限制性FoxM 1缺陷的小鼠中检查LPS诱导的血管损伤后肺血管的渗漏和修复失败的超微结构缺陷和细胞性质。

DESCRIPTION (provided by applicant): Recovery of endothelial integrity after lung vascular injury is a poorly understood aspect of vascular homeostasis. Our long term goals using molecular, cellular, and in vivo approaches are to elucidate mechanisms of endothelial barrier repair following vascular injury and identify novel therapeutic targets to prevent persistent lung vascular injury and leaky microvessels associated with sepsis-induced acute lung injury. FoxM1 is a member of the Forkhead box (Fox) family of transcription factors essential for cell proliferation. FoxM1-null mutation in mice causes embryonic lethality due to improper execution of mitosis and the resulting polyploid cells in heart and liver. We will test the general HYPOTHESIS that FoxM1 is a critical determinant of endothelial repair following lung vascular injury. Our objective is to determine the essential role of FoxM1 in regulating endothelial cell proliferation and re-annealing endothelial junctions, thereby restoring endothelial integrity following lung vascular injury. The studies will address the following Specific Aims: 1. To determine the mechanisms of regulation of FoxM1 expression in response to lung vascular injury. We will dissect the signaling pathways that mediate FoxM1 induction in the pulmonary microvasculature following LPS-induced lung vascular injury. We will test the hypothesis that loss of endothelial cell-cell contact following lung vascular injury induces FoxM1 expression in endothelial cells through PI3K/Akt-dependent downregulation of p27Kip1, a key determinant of cell contact inhibition. 2. To elucidate the molecular mechanisms of FoxM1-regulated endothelial cell proliferation. We will characterize the defects in cell cycle progression of FoxM1 -deficient pulmonary endothelial cells and identify the FoxM1 transcriptional network of genes essential for endothelial cell proliferation. We will also dissect the mechanisms involved in FoxM1 regulation of p27Kip1. 3. To determine the role of FoxM1 in the mechanism of restoring endothelial integrity. We will address the possibility that FoxM1 plays an important role in re-organizing the endothelial cell-cell junctions following lung vascular injury. We will also examine following LPS-induced vascular injury the ultrastructural defects and the cellular nature of the leaks and repair failure of the pulmonary vasculature in mice with endothelial cell- restricted deficiency of FoxM1.