Fibroblast Biology and Pulmonary Fibrosis

项目总结 特发性肺纤维化(IPF)是一种以肺部进行性瘢痕形成为特征的疾病，导致 肺功能恶化，中位生存期为3.5年。肺纤维化被认为是一种疾病 伤口愈合异常，其中纤维化反应的初始触发因素是对肺泡的损伤 然后是一种旺盛的、未溶解的伤口愈合反应。转化生长因子-β是血管生成中的关键细胞因子 肺纤维化的发病机制。转化生长因子-β诱导成纤维细胞分化为肌成纤维细胞是关键 肺纤维化的发病过程；然而，肌成纤维细胞激活的机制是 不能完全理解。 在使用微阵列研究的一种无偏见的方法中，我们确定了Anoctamin-1(ANO1)，也称为 TMEM16A作为转化生长因子-β高度上调的基因之一，促进细胞的增殖、迁移 肺成纤维细胞向肌成纤维细胞分化。我们的数据还表明，ANO1在 在IPF患者的肺部，定位于IPF肺纤维化区域。ANO1在肌成纤维细胞中的作用 活化和肺纤维化的研究一直很少。由于ANO1是一种钙激活的氯化物 通道中，我们用-NO-赖氨酸激酶-1(WNK1)评价了氯敏感蛋白激酶的作用。 与ANO1类似，ANO1有助于肌成纤维细胞的激活。根据我们的初步数据，我们假设 ANO1是一种促纤维化蛋白，通过WNK1促进肌成纤维细胞活化和肺纤维化 路径。为了验证我们的假设，我们提出了以下具体目标： 具体目标#1.确定ANO1介导的细胞内氯水平控制如何激活人肺 成纤维细胞(HLFS)。 特定目的#2.确定HLF中ANO1和WNK1激活成纤维细胞的信号机制。 特定目的#3.通过有条件地敲除ANO1，阐明ANO1在活体肺中的促纤维化作用 成纤维细胞。

PROJECT SUMMARY Idiopathic pulmonary fibrosis (IPF) is a disease characterized by progressive scarring of the lungs resulting in deterioration in lung function with a median survival of 3.5 years. Pulmonary fibrosis is thought to be a disorder of abnormal wound healing, wherein the initial trigger to the fibrotic response is injury to the alveolar epithelium, followed by an exuberant, non-resolving wound-healing response. TGF-β is the key cytokine in the pathogenesis of pulmonary fibrosis. TGF-β-driven differentiation of fibroblasts into myofibroblasts is a key process in the pathogenesis of pulmonary fibrosis; however, the mechanisms of myofibroblast activation are not completely understood. In an unbiased approach using microarray studies, we identified Anoctamin-1 (ANO1), also known as TMEM16A, as one of highly upregulated genes in response to TGF-β contributing to the proliferation, migration and differentiation of lung fibroblasts to myofibroblasts. Our data also suggest that ANO1 is increased in the lungs of IPF patients and is localized to the fibrotic areas in the IPF lung. The role of ANO1 in myofibroblast activation and pulmonary fibrosis has been poorly investigated. Since ANO1 is a calcium-activated chloride channel, we evaluated the role of chloride-sensitive protein kinase, With-No-Lysine Kinase-1 (WNK1), which similarly to ANO1 contributed to myofibroblast activation. Based on our preliminary data, we hypothesize that ANO1 is a pro-fibrotic protein promoting myofibroblast activation and pulmonary fibrosis through WNK1 pathway. To test our hypothesis, we propose the following specific aims: Specific Aim #1. Determine how ANO1-mediated control of intracellular chloride levels activates human lung fibroblasts (HLFs). Specific Aim #2. Determine the signaling mechanisms of fibroblast activation through ANO1 and WNK1 in HLF. Specific Aim #3. Elucidate the profibrotic role of ANO1 in the lung in vivo by a conditional knockout of ANO1 in fibroblasts.