Acta Biomaterialia ( IF 9.4 ) Pub Date : 2018-03-07 , DOI: 10.1016/j.actbio.2018.02.037 Vijay Krishna Raghunathan 1 , Julia Benoit 2 , Ramesh Kasetti 3 , Gulab Zode 3 , Michelle Salemi 4 , Brett S Phinney 4 , Kate E Keller 5 , Julia A Staverosky 5 , Christopher J Murphy 6 , Ted Acott 5 , Janice Vranka 5
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Ocular hypertension is a causal risk-factor to developing glaucoma. This is associated with stiffening of the trabecular meshwork (TM), the primary site of resistance to aqueous-humor-outflow. The mechanisms underlying this stiffening or how pathologic extracellular matrix (ECM) affects cell function are poorly understood. It is recognized that mechanotransduction systems allow cells to sense and translate the intrinsic biophysical properties of ECM into intracellular signals to control gene transcription, protein expression, and cell behavior. Using an anterior segment perfusion model, we document that there are significantly more low flow regions that are much stiffer, and fewer high flow regions that are less stiff in glaucomatous TM (GTM) when compared to non-glaucomatous TMs (NTM). GTM tissue also has fewer cells overall when compared with NTM tissue. In order to study the role of pathologic ECM in glaucoma disease progression, we conducted studies using cell derived matrices (CDM). First, we characterized the mechanics, composition and organization of fibronectin in ECM deposited by GTM and NTM cells treated with glucocorticosteroids. Then, we determined that these GTM-derived ECM are able to induce stiffening of normal NTM cells, and alter their gene/protein expression to resemble that of a glaucomatous phenotype. Further, we demonstrate that GTM-derived ECM causes endoplasmic reticular stress in NTM. They also became resistant to being reorganized by these NTM cells. These phenomena were exacerbated by ECMs obtained from steroid treated glaucoma model groups. Collectively, our data demonstrates that CDMs represent a novel tool for the study of bidirectional interactions between TM cells and their immediate microenvironment.
Statement of Significance
Extracellular matrix (ECM) changes are prevalent in a number of diseases. The precise mechanisms by which changes in the ECM contribute to disease progression is unclear, primarily due to absence of appropriate models. Here, using glaucoma as a disease model, we document changes in cell derived matrix (CDM) and tissue mechanics that contribute to the pathology. Subsequently, we determine the effect that ECMs from diseased and healthy individuals have on healthy cell behaviors. Data emanating from this study demonstrate that CDMs are a potent tool for the study of cell-ECM interactions.
中文翻译：
青光眼细胞衍生的基质差异调节非青光眼小梁网细胞行为。
高眼压是发生青光眼的危险因素。这与小梁网（TM）的硬化有关，小梁网是抵抗房水流出的主要部位。这种硬化的机制或病理性细胞外基质 (ECM) 如何影响细胞功能尚不清楚。人们认识到，机械转导系统允许细胞感知 ECM 的内在生物物理特性并将其转化为细胞内信号，以控制基因转录、蛋白质表达和细胞行为。使用眼前节灌注模型，我们记录到与非青光眼 TM (NTM) 相比，青光眼 TM (GTM) 中明显有更多更硬的低流量区域，并且更少的高流量区域。与 NTM 组织相比，GTM 组织的细胞总数也较少。为了研究病理 ECM 在青光眼疾病进展中的作用，我们使用细胞衍生基质 (CDM) 进行了研究。首先，我们表征了经糖皮质激素处理的 GTM 和 NTM 细胞沉积的 ECM 中纤连蛋白的力学、组成和组织。然后，我们确定这些 GTM 衍生的 ECM 能够诱导正常 NTM 细胞硬化，并改变其基因/蛋白质表达以类似于青光眼表型。此外，我们证明 GTM 衍生的 ECM 会导致 NTM 中的内质网状应激。它们也对这些 NTM 细胞的重组产生了抵抗力。从类固醇治疗的青光眼模型组获得的 ECM 加剧了这些现象。总的来说，我们的数据表明，CDM 是研究 TM 细胞与其直接微环境之间双向相互作用的一种新工具。
重要性声明
细胞外基质（ECM）变化在许多疾病中普遍存在。 ECM 变化导致疾病进展的确切机制尚不清楚，主要是由于缺乏合适的模型。在这里，我们使用青光眼作为疾病模型，记录了细胞衍生基质（CDM）和组织力学对病理学的影响。随后，我们确定了来自患病和健康个体的 ECM 对健康细胞行为的影响。这项研究的数据表明，CDM 是研究细胞-ECM 相互作用的有效工具。
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