Engineering a Kidney Organoid Model to Investigate Fibronectin-TGF-beta Signaling in Renal Fibrosis

设计肾脏类器官模型来研究肾纤维化中的纤连蛋白-TGF-β信号传导

• 批准号: 2302580
• 负责人: Christopher Lemmon
• 金额: $ 53.6万
• 依托单位: Virginia Commonwealth University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2302580&HistoricalAwards=false
• 关键词: Engineering; Kidney; Organoid; Model; Investigate

Chronic kidney disease (CKD) is estimated to affect approximately 11-13% of the global population. CKD is driven by scarring of kidney tissue, a process known as “renal fibrosis”. This process is dramatically affected by both the protein TGF-beta, which is secreted by inflammatory cells, and the protein fibronectin, which is a structural protein assembled into fibrils by cells to build new tissue. The process of fibrosis is confounded by two issues. First, TGF-beta induces cells to assemble fibronectin into fibrils, while fibronectin fibrils bind TGF-beta and induce cells to respond to it; this feedback makes it difficult to separate cause-and-effect in fibrosis. Second, multiple cell types in the kidney can secrete TGF-beta, secrete fibronectin, and assemble fibronectin into fibrils, making it difficult to distinguish the contributions of different cell types to the progression of fibrosis. This project will address this complexity by developing hollow spheres of kidney cells that mimic kidney tissue. Removal/ inhibition of specific cell types and/or elements of TGF-beta and fibronectin signaling will allow for a deeper understanding of how these proteins contribute to renal fibrosis. The impact of this work will be expanded by developing a four-session symposium targeted to high school students and community college students from under-represented communities that focuses on the fundamentals of kidney function and cell biology.CKD is driven by renal fibrosis, which is a process of excess assembly of extracellular matrix. The interplay between the immune cytokine TGF-beta and the extracellular matrix protein fibronectin in renal fibrosis is incompletely understood. In response to inflammatory signals, the cytokine TGF-beta is released from immune cells. TGF-beta drives increased secretion of the extracellular matrix protein fibronectin and subsequent assembly of fibronectin into a scaffold of fibrils. Immune cell-derived TGF-beta also drives an increased secretion of endogenous TGF-beta, which subsequently binds to the scaffold of fibronectin fibrils. Collectively, these drive alterations in renal tubule morphology, renal tubule function, and extracellular matrix remodeling that occur during renal fibrosis. In this work, a reductionist approach will be used to identify the contribution of fibronectin fibril assembly, endogenous TGF-beta secretion, and TGF-beta/fibronectin tethering to renal fibrosis and kidney damage. To better understand their respective roles, renal tubule spheroids will be engineered that will serve as a platform for investigating TGF-beta/fibronectin interactions in renal fibrosis. This renal tissue mimetic will consist of renal epithelial cells, fibroblasts, and pericytes, as well as relevant tubulo-interstitial extracellular matrix components. The work will first determine if these renal mimetics recapitulate kidney tubule polarity and tubular function and will demonstrate that known inducers of renal fibrosis drive similar changes in the renal spheroids. The following system elements will then be perturbed: i) the assembly of fibronectin into extracellular matrix fibrils, ii) the expression and secretion of endogenous TGF-beta, and iii) the localization and tethering of TGF-beta to fibronectin fibrils to better understand the interactions between these key constituents.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

据估计，慢性肾病 (CKD) 影响着全球约 11-13% 的人口。慢性肾病是由肾组织疤痕引起的，这一过程被称为“肾纤维化”。该过程受到 TGF-β 蛋白的显着影响。由炎症细胞分泌的纤维连接蛋白和纤维连接蛋白，这是一种由细胞组装成原纤维以构建新组织的结构蛋白。纤维化的过程受到两个问题的困扰。 TGF-β 诱导细胞将纤连蛋白组装成原纤维，而纤连蛋白原纤维结合 TGF-β 并诱导细胞对其做出反应；这种反馈使得很难区分纤维化的因果关系。分泌 TGF-β、分泌纤连蛋白并将纤连蛋白组装成原纤维，从而难以区分不同细胞类型对纤维化进展的贡献。该项目将解决这一问题。这种复杂性是由模拟肾组织的肾细胞空心球体形成的，去除/抑制特定细胞类型和/或 TGF-β 和纤连蛋白信号传导元件将有助于更深入地了解这些蛋白质如何导致肾纤维化。这项工作将通过举办一个针对代表性不足社区的高中生和社区学院学生的四次研讨会来扩大，重点关注肾功能和细胞生物学的基础知识。CKD 是由肾纤维化驱动的，肾纤维化是一个细胞外基质的过度组装。免疫细胞因子 TGF-β 和细胞外基质蛋白纤连蛋白在肾纤维化中的相互作用尚不完全清楚。响应炎症信号，免疫细胞释放细胞因子 TGF-β。细胞外基质蛋白纤连蛋白的分泌以及随后纤连蛋白组装成原纤维支架也驱动内源性分泌的增加。 TGF-β，随后与纤连蛋白原纤维的支架结合，共同驱动肾纤维化过程中发生的肾小管形态、肾小管功能和细胞外基质重塑的改变。纤连蛋白原纤维组装、内源性 TGF-β 分泌和 TGF-β/纤连蛋白束缚对肾纤维化和肾脏损伤的贡献，以更好地了解它们各自的作用。肾小管球体将被设计为研究肾纤维化中 TGF-β/纤连蛋白相互作用的平台。这种肾组织模拟物将由肾上皮细胞、成纤维细胞和周细胞以及相关的肾小管间质细胞外细胞组成。这项工作将首先确定这些肾模拟物是否重现肾小管极性和肾小管功能，并将证明已知的肾纤维化诱导剂驱动类似的作用。然后，以下系统元素将受到干扰：i) 纤连蛋白组装成细胞外基质原纤维，ii) 内源性 TGF-β 的表达和分泌，以及 iii) TGF-β 的定位和束缚。纤连蛋白原纤维，以更好地了解这些关键成分之间的相互作用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响进行评估，被认为值得支持审查标准。