Inhibition of Fgr Prevents Pulmonary Fibrosis

肺纤维化可自发发生，如特发性肺纤维化(IPF)或电离后 辐射、二氧化硅暴露或新冠肺炎感染。衰老与辐射诱导的 肺纤维化(RIPF)和IPF。新冠肺炎报道，小鼠肾间质纤维化发生在衰老之前 病人。用抗衰老药物清除衰老细胞(SCs)是一种有吸引力的抗纤维化策略。 然而，感觉剂可能是非特异性的，可以去除潜在的有益和有害的SC。小才是 知道衰老细胞如何导致肺纤维化。SCS退出细胞周期，诱导p16增加 衰老相关β-半乳糖苷酶(SA-𝝱-GAL)和分泌衰老相关分泌 表型(SASP)蛋白。SASP包括可能引发和加剧纤维化的促炎细胞因子。 因此，利用辐射作为诱导衰老的模型系统，我们建议建立并验证 通过靶向一种衰老蛋白而不去除干细胞来特效缓解肺纤维化。由RNA-seq of 通过对受照肺的单细胞RNA-seq(ScRNAseq)分析，我们发现酪氨酸激酶FGR是 在衰老细胞中高度诱导。FGR阳性小鼠肺细胞体外诱导纤维化生物标志物 抑制剂，TL02-59处理，消除了促纤维化基因的诱导。我们的初步数据显示：1)在 小鼠肺衰老细胞，FGR抑制剂TL02-59可阻断靶细胞中促纤维化基因的诱导，2) 在FGR基因敲除小鼠的肺细胞中，辐射引起衰老，但不能诱导肺纤维化基因的表达。 靶细胞，3)来自RIPF、矽肺和IPF的人肺显示FGR和衰老标志物的诱导 P16，4)TL02-59减少促纤维化SASP趋化因子的分泌以吸引免疫细胞，5)抑制 在体内，TL02-59或衰老抑制剂MMS350的FGR可减少纤维化基因的表达。我们 假设，衰老细胞中的FGR通过分泌促炎性SASP蛋白启动肺纤维化 并通过将炎性免疫细胞招募到肺部。我们进一步假设对FGR的抑制是通过小剂量的 分子TL02-59或通过衰老抑制剂MMS350间接作用可预防肺纤维化。我们将使用 C57BL/6对照和FGR基因敲除(FGR-/-)小鼠原代肺细胞在体内确认FGR的作用 在C57BL/6和C57BL/6 FGR-/-小鼠中。最后，我们将确定FGR的特异性抑制可以预防肺 纤维化症。特定目标1将确定肺细胞衰老诱导FGR并启动肺纤维化 通过分泌型促炎因子SASP和骨髓向肺的募集作用 衍生的炎性细胞。特定目标2将使用FGR-/-确定肺纤维化需要FGR 老鼠。具体目标3将确定FGR的特异性和靶向性药物抑制可阻断肺纤维化。 我们的创新方法将建立FGR在衰老肺细胞中的诱导 通过分泌促炎性SASP蛋白和趋化募集 炎性细胞。我们建议的研究将导致开发一种新的肺纤维化缓解剂。

Pulmonary fibrosis can arise spontaneously as in idiopathic pulmonary fibrosis (IPF), or following ionizing irradiation, silica exposure, or COVID-19 infection. Senescence has been implicated in both radiation-induced pulmonary fibrosis (RIPF) and IPF. Senescence precedes fibrosis in mouse RIPF and reported in COVID-19 patients. Clearance of senescent cells (SCs) by senolytic drugs present an attractive anti-fibrosis strategy. However, senolytics may be non-specific and remove potentially beneficial as well as harmful SCs. Little is known about how senescent cells induce pulmonary fibrosis. SCs exit cell cycle, induce p16, increase senescence associated beta-galactosidase (SA-𝝱-gal), and secrete senescence associated secretory phenotype (SASP) proteins. SASP include proinflammatory cytokines that may initiate and exacerbate fibrosis. Therefore, using radiation as a model system to induce senescence, we propose to establish and validate a specific mitigator of lung fibrosis by targeting one senescent protein while not removing the SCs. By RNA-seq of pure SCs and by single cell RNA-seq (scRNAseq) of irradiated lungs, we discovered that tyrosine kinase Fgr is highly induced in senescent cells. Fgr positive mouse lung cells induce biomarkers of fibrosis in vitro, and Fgr inhibitor, TL02-59 treatment, abrogates the induction of profibrotic genes. Our preliminary data show: 1) in mouse lung senescent cells, Fgr inhibitor TL02-59 abrogates the induction of profibrotic genes in target cells, 2) in lung cells from Fgr knockout mouse, senescence occurs with radiation, but fail to induce profibrotic genes in target cells, 3) human lungs from RIPF, silicosis, and IPF show induction of Fgr and senescent marker p16, 4) TL02-59 reduces secretion of profibrotic SASP chemokines for attracting immunocytes, 5) inhibition of Fgr in vivo, either by TL02-59, or by senescence inhibitor MMS350, reduces expression of fibrotic genes. We hypothesize, Fgr in senescent cells initiates pulmonary fibrosis by secretion of proinflammatory SASP proteins and by recruiting inflammatory immunocytes to the lungs. We further hypothesize that inhibition of Fgr by small molecule TL02-59 or indirectly by the senescence inhibitor, MMS350, will prevent lung fibrosis. We will use mouse primary lung cells from C57BL/6 control and Fgr knockout (Fgr-/-) mice to confirm the role of Fgr in vivo in C57BL/6 and C57BL/6 Fgr-/- mice. Finally, we will establish that specific inhibition of Fgr prevents lung fibrosis. Specific Aim 1 will establish that lung cell senescence induces Fgr and initiates pulmonary fibrosis by the actions of secreted proinflammatory SASP and recruitment to the lungs of bone marrow derived inflammatory cells. Specific Aim 2 will establish that Fgr is required for pulmonary fibrosis using Fgr -/- mice. Specific Aim 3 will establish that specific and targeted pharmacologic inhibition of Fgr blocks lung fibrosis. Our innovative approach will establish that Fgr induction in senescent lung cells causes pulmonary fibrosis through secretion of proinflammatory SASP proteins and chemotactic recruitment of inflammatory cells. Our proposed studies will lead to the development of a new mitigator of pulmonary fibrosis.