The role of SPARC in lung fibrosis

SPARC在肺纤维化中的作用

• 批准号: 8432592
• 负责人: Elizabeth A Putnam
• 金额: $ 42万
• 依托单位: UNIVERSITY OF MONTANA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-21 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8432592
• 关键词: Address; Amphibole Asbestos; Amphiboles; Asbestos; Asbestosis; Attention; Breathing; Candidate Disease Gene; Cell Communication; Cell Line; Cells; Chronic; Crocidolite Asbestos; Cysteine; Deposition; Development; Disease; Disease Progression; Elements; Environmental Exposure; Exposure to; Extracellular Matrix; Fiber; Fibroblasts; Fibrosis; Gene Expression; Goals; Growth Factor; Hamman-Rich syndrome; Health; Home environment; Human; Human Cell Line; In Vitro; Incidence; Individual; Inflammation; Investigation; Lung; Lung diseases; Maintenance; Malignant neoplasm of lung; Measures; Mesothelioma; Mining; Molecular; Montana; Mus; Pathway interactions; Patients; Play; Population; Process; Production; Proteins; Public Health; Pulmonary Fibrosis; RNA Interference; Regulation; Research Design; Rest; Risk; Role; Signal Transduction; Site; Testing; Time; United States; United States Environmental Protection Agency; Wild Type Mouse; improved; in vivo; lung development; mouse model; new therapeutic target; operation; protein expression; public health relevance; response; superfund site; vermiculite

DESCRIPTION (provided by applicant): National attention has been drawn to asbestos-related diseases (ARD) due to the serious health situation in Libby, Montana. For almost 60 years Libby miners and residents were exposed to asbestos- contaminated vermiculite from a mining operation near town. Both occupationally- and environmentally- exposed individuals have shown a much higher incidence of ARD than the rest of the population (ATSDR, 2003). However, exposure to the asbestos-contaminated vermiculite is not limited to Libby residents: distribution of this vermiculite nationwide and the long latent period for disease development make asbestos-related diseases (ARD) a continuing public health issue. We previously investigated gene expression changes in a mouse model of asbestos exposure and identified a candidate gene for study that we hypothesize plays a role in disease progression. SPARC (secreted protein acidic and rich in cysteine) demonstrates reproducibly increased expression in mouse lungs exposed to several types of asbestos fibers, including the Libby amphibole. SPARC is a matricellular protein involved in the regulation of extracellular matrix (ECM) - cell interactions through a hypothesized modulation of growth factor activity. The goal of this project is to delineate the role of SPARC in response to exposure to the Libby amphibole and crocidolite asbestos as a positive control. The hypothesis to be tested in our studies is that expression of SPARC is a significant step in the development of lung fibrosis after asbestos exposure. To test the hypothesis, the specific aims will 1) ssess the in vivo expression of SPARC and proteins in the TGF-¿ signaling cascade in SPARC-null and matched wild-type mice after induction of lung fibrosis through intratracheal asbestos instillation, and compare this with the effects of subsequent RNAi transduction to control SPARC expression in wild-type mice, and 2) establish the in vitro gene and protein expression of SPARC as well as extracellular matrix production in mouse primary lung fibroblasts and an immortalized human lung fibroblast cell line stimulated by TGF-¿ or amphiboles before and after Sparc expression inhibition by RNAi. The investigation proposed here will further determine the role of SPARC in fibrosis development after amphibole exposure, specifically targeting how inhibition of SPARC expression can regulate ECM production. Proteins involved in pathways regulated by SPARC could provide targets for potential therapies that might also be beneficial for the treatment of similar, non-asbestos caused diseases such as idiopathic pulmonary fibrosis.

描述（由申请人提供）：由于蒙大拿州利比的严重健康状况，全国关注石棉相关疾病（ARD）。近60年来，利比的矿工和居民一直暴露在城镇附近采矿作业中石棉污染的蛭石中。职业和环境接触者的急性呼吸窘迫综合征发病率都比其他人群高得多（美国毒物与疾病登记署，2003年）。然而，接触石棉污染的蛭石并不限于利比居民：这种蛭石在全国范围内的分布和疾病发展的长期潜伏期使石棉相关疾病（ARD）成为一个持续的公共卫生问题。我们先前研究了石棉暴露小鼠模型中的基因表达变化，并确定了一个候选基因，我们假设该基因在疾病进展中起作用。在暴露于几种类型的石棉纤维（包括Libby闪石）的小鼠肺中，C18（分泌的酸性蛋白质，富含半胱氨酸）的表达可重复增加。细胞外基质（ECM）是一种基质细胞蛋白，通过假设的生长因子活性调节参与细胞外基质（ECM）-细胞相互作用的调节。本项目的目标是描述在暴露于利比角闪石和青石棉作为阳性对照时，石棉的作用。在我们的研究中要检验的假设是，在石棉暴露后肺纤维化的发展过程中，β-淀粉样蛋白的表达是一个重要的步骤。为了验证这一假设，具体的目的是：1）在通过气管内注入石棉诱导肺纤维化后，评估SPARC-敲除小鼠和匹配的野生型小鼠中TGF-β信号级联中的TGF-β和蛋白质的体内表达，并比较这一点。 与随后的RNAi转导的作用，以控制野生型小鼠中的Sparc表达，和2）在通过RNAi抑制Sparc表达之前和之后，在小鼠原代肺成纤维细胞和由TGF-β或闪石刺激的永生化人肺成纤维细胞系中建立Sparc的体外基因和蛋白表达以及细胞外基质产生。本文提出的研究将进一步确定角闪石暴露后，β-淀粉样蛋白在纤维化发展中的作用，特别是针对β-淀粉样蛋白表达的抑制如何调节ECM的产生。参与由石棉调节的途径的蛋白质可以为潜在的治疗提供靶点，这些治疗也可能有益于治疗类似的非石棉引起的疾病，如特发性肺纤维化。