Metabolic reprogramming of endothelial precursor cells in subretinal fibrosis

针对血管内皮生长因子(VEGF)的治疗药物取得了显著的效果 新血管型老年性黄斑变性(NAMD)患者治疗成功。一种新兴的 然而，临床问题是，许多NAMD患者在接受治疗后发展为视网膜下纤维化(SRF)。 抗血管内皮生长因子治疗。SRF可以对视网膜造成不可逆转的结构性损伤，是一个主要的愿景- 危险的并发症，没有有效的治疗。NAMD中SRF的发病机制主要是 未知。转化生长因子β(TGF-β)是纤维化的主要驱动力。转化生长因子-β的来源 SRF及其主要效应细胞尚未得到很好的定义。SRF可在自发性或慢性阻塞性肺疾病的小鼠中建立 实验诱导的脉络膜新生血管(CNV)。在我们发表的和初步的研究中，我们发现 极低密度脂蛋白受体(Vldlr)基因定向缺失的小鼠在以下情况下发生SRF CNV病变消退。通过单细胞RNA测序，我们鉴定了内皮前体细胞 (内皮祖细胞)作为一群主要的细胞，显示出纤维化的标志。JR5558也观察到了类似的发现 在小鼠和激光诱导的CNV中。内皮祖细胞具有干细胞样的特性，它们被招募到脉络膜 和视网膜新生血管，以促进血管修复。在视网膜下微环境中，内皮祖细胞逐渐丧失 它们的细胞结构和转分化为成纤维细胞样细胞。我们假设转化生长因子-β介导的 内皮祖细胞的代谢重新编程是一个关键的信号事件，有助于血管内皮细胞的形成和发展。 CNV后SRF。对于本申请中提出的项目，我们将确定EPC在鼠标中的角色 湿性AMD的CNV模型和人供体眼组织。我们还将检查新陈代谢 对转化生长因子-β反应的内皮祖细胞的重新编程。此外，我们将探讨穆勒细胞来源的IL-1是否 33促进巨噬细胞产生转化生长因子-β，以及抑制IL-33信号是否抑制 SRF。这些研究的结果将揭示SRF的新的分子和细胞机制，并定义新的 潜在治疗干预的目标。

Therapeutic agents that target the vascular endothelial growth factor (VEGF) have achieved remarkable success in patients with the neovascular form of age-related macular degeneration (nAMD). An emerging clinical problem, however, is that many of the nAMD patients develop subretinal fibrosis (SRF) after receiving anti-VEGF therapy. SRF can cause irreversible structural damage to the retina and is a major vision- threatening complication with no effective treatment. The disease mechanisms of SRF in nAMD are largely unknown. Transforming growth factor beta (TGF-beta) is a major driver of fibrosis. The source of TGF-beta in SRF, and its main effector cells, have not been well defined. SRF can be modeled in mice with spontaneous or experimentally-induced choroidal neovascularization (CNV). In our published and preliminary studies, we found that mice with targeted deletion in the very low-density lipoprotein receptor (Vldlr) gene developed SRF when their CNV lesions regressed. Using single cell RNA sequencing, we identified endothelial precursor cells (EPCs) as a major cluster of cells that displayed markers of fibrosis. Similar findings were observed in JR5558 mice and in laser-induced CNV. EPCs have stem cell-like properties, and they are recruited to the choroidal and retinal neovessels to facilitate the vascular repair. In the subretinal microenvironment, EPCs gradually lose their cellular structures and transdifferentiate into fibroblast-like cells. We hypothesize that TGF-beta-mediated metabolic reprograming of EPCs is a key signaling event that contributes to the formation and progression of SRF after CNV. For the project proposed in this application, we will determine the roles of EPCs in mouse models of CNV and in human donor eye tissues with wet AMD. We will also examine the metabolic reprogramming of EPCs in response to TGF-beta. Furthermore, we will explore whether Muller cell-derived IL- 33 promotes TGF-beta production from macrophages, and whether inhibiting the IL-33 signaling suppresses SRF. Results from these studies will reveal novel molecular and cellular mechanisms of SRF, and define new targets for potential therapeutic intervention.