Macrophage-specific Pair Immunoglobulin-like Type 2 Receptor beta (PILRB) regulation of Pulmonary Hypertension

摘要 肺高压(PH)，由原发肺血管疾病引起或继发于许多其他疾病 这种疾病与高发病率和高死亡率有关。尽管最近在治疗方面取得了进展，但PH 住院和死亡率继续上升。开发有效的治疗方法是必要的，但受到 我们对调节肺血管的细胞和机制了解的基础知识差距 重塑是PH发生的基础。巨噬细胞(M？)在动物模型和 人类PH提示单核细胞/S在调节PH发病机制中的作用，我的K08奖集中在 明确单核细胞/M？S在PH发病中的作用。我证明了非经典单核细胞 (NcMOS)通过低氧诱导因子-1α(HIF1α)感知低氧，并分化为促血管生成 重塑间质M？S(IM？S)，促进PH的发展。有效针对性地促进这些疾病的发生 为了减轻疾病，细胞需要了解它们调节血管的机制 改建。我确定配对的免疫球蛋白样2型受体β(PILRβ)是NcMo来源的候选基因 IM？-特异性疾病介体。我们假设，作为对缺氧和HIF1α激活的反应：1)PILRβ 浸润性IM？S的表达增加；2)PILRβ与其受体CD99结合于血管结构细胞 (即内皮细胞、血管平滑肌细胞和成纤维细胞)以增加细胞因子的产生(例如 肿瘤坏死因子、白介素1β和白介素6)促进肺血管重塑和肺高压的发生发展。我们的初步研究 研究表明，在缺乏β的IM？S中，pILR-α的基因表达降低。 降低促血管重塑细胞因子(即肿瘤坏死因子、白介素1和白介素6)的表达，以及减轻高血压的严重程度 血管重塑与肺高压。这些发现表明，PILRβ是一种NcMo/IM？特异性的调节介质 PH发病机制。利用My K08期间开发的转基因动物和人PAH肺组织收集 目的1.确定PILRβ的表达模式 小鼠和人肺高压模型中的受体复合体及其HIF1α的调节NcMo特异性HIF1α 基因敲除小鼠将在低氧诱导的PH模型中进行检查，以确定PILRβ在 PH的发展历程。此外，还将检测PILRβ在人肺组织中的表达。目标2.确定 表达PILRβ配体CD99的细胞及其对慢性低氧反应的配体表达 在人类PH中也是如此。CD99的表达将在低氧诱导的PH形成过程中被检测 PH值和人PAH肺组织块。目的3.确定PH发育过程中的细胞因子反应，即 经调理通脉通络，促进血管重塑。PH病程中的细胞因子反应 将在NcMo特异的HIF1HIF1基因敲除小鼠和人类α肺外植体中检查发育情况。这个 拟议的研究将提供初步数据，以支持专注于检查PILRβ的R01应用程序 作为一种潜在的治疗策略。

ABSTRACT Pulmonary hypertension (PH), arising from primary pulmonary vascular disease or secondary to many other conditions, is associated with high morbidity and mortality. Despite recent therapeutic advancements, PH hospitalization and mortality continue to rise. Development of effective therapy is needed but is limited by a fundamental knowledge gap in our understanding of cells and mechanisms that regulate pulmonary vascular remodeling underlying PH development. Macrophage (MØ) accumulation is observed in animal models and human PH suggesting a role for monocytes/MØs in regulating PH pathogenesis, My K08 award centered on defining the contribution of monocytes/MØs to PH pathogenesis. I demonstrated that non-classical monocytes (NcMos) sense hypoxia, through hypoxia inducible factor-1α (HIF1α), and differentiate into pro-vascular remodeling interstitial MØs (IMØs) that promote PH development. Effective targeting of these disease promoting cells to alleviate disease will require an understanding of mechanisms by which they regulate vascular remodeling. I identified paired immunoglobulin-like type 2 receptor beta (PILRβ) as a candidate NcMo-derived IMØ-specific disease mediator. We hypothesize that, in response to hypoxia and activation of HIF1α: 1) PILRβ expression in infiltrating IMØs is increased and 2) PILRβ engages its receptor, CD99, on vascular structural cells (i.e. endothelial cells, vascular smooth muscle cells, and fibroblasts) to increase the production of cytokines (e.g. TNF, IL-1β, and IL-6) that promote pulmonary vascular remodeling and PH development. Our preliminary studies show that gene expression of PILRβ is decreased in Hif1α-deficient IMØs. This decrease is associated with lower expression of pro-vascular remodeling cytokines (i.e. TNF, IL-1, and IL6), as well as reduced severity of vascular remodeling and PH. These findings suggest that PILRβ is a NcMo/IMØ-specific mediator that modulates PH pathogenesis. Utilizing transgenic animal and human PAH lung tissue collection developed during my K08 award, we propose the following specific aims: Aim 1. To determine the expression patterns of PILRβ receptor complex and its regulation by HIF1α in a murine model and human PH. NcMo-specific Hif1α knockout mice will be examined in a model of hypoxia-induced PH to define PILRβ expression pattern over the course of PH development. PILRβ expression in human PAH lung will also be examined. Aim 2. To determine the cells that express CD99, a ligand for PILRβ, and ligand expression in response to chronic hypoxia and in human PH. CD99 expression will be examined over the course of PH development in hypoxia-induced PH and human PAH lung explants. Aim 3. To determine cytokine response during PH development that is modulated by infiltrating IMØs to promote vascular remodeling. Cytokine responses over the course of PH development will be examined in NcMo-specific Hif1α knockout mice and in human PAH lung explants. The proposed studies will provide the preliminary data to support an R01 application focused on examining PILRβ as a potential therapeutic strategy for PH.