Elucidating the role of cardiac myofibroblasts on matrix and vasculature remodeling

在各种形式的心脏病中，细胞外基质(ECM)的分泌被激活 成纤维细胞或肌成纤维细胞会导致心脏纤维化。纤维化阻碍合规性和 泵功能，最终导致心力衰竭，由于左心室扩张和丧失 机械功能。对血管内皮细胞和血管对血管的适应知之甚少 环境或局部力学和化学如何影响体内的血管结构和流动。 成纤维细胞和细胞外基质与内皮细胞的机械和化学串扰 未知。此外，旨在评估血管对细胞外环境适应性的体外模型 环境缺乏生理上相关的ECM，而是提供外源ECM 组件，以优化变量控制。一种体内、细胞特异性表型的系统 操作将允许器官水平上的受控扰动，同时保持相关的， 随着时间的推移，天然的细胞外基质重塑。因此，我建议用心脏转基因小鼠进行检测。 成纤维细胞特异性过表达有丝分裂原激活的蛋白激酶 激酶6(MKK6)研究成纤维细胞和细胞外基质的血管重塑 秘密的。这些小鼠先前被证明在 16-20周的MKK6基因激活无损伤刺激，起到了有效的 跨增龄、高血压、主动脉病变的间质纤维化模型 狭窄，以及其他心脏疾病。重要的是，在这些疾病中看到的重塑 并不像心肌梗死那样涉及心肌细胞的大量丧失，而是 保守的成纤维细胞表型改变，细胞外间隙改变，和/或受限 随着时间的推移，血管流动。同样，对MKK6通路的操纵也允许过度表达 或抑制心脏成纤维细胞的激活，对应于细胞外基质增加或无法 分别分泌ECM作为对刺激的反应。首先，我建议研究 ECM的生化、结构和机械性能以及宏观和 微血管对心脏成纤维细胞表型的激活、静止和控制的反应 活着。其次，具有可控成纤维细胞和细胞外基质的三维血管样结构将 被设计成体外平台来定义血管重塑的分子调节 由微环境线索引起的。组合信令的影响将通过以下方式解决 全局性描述以及一种简化论的方法。这项工作的目的是让心灵知道 通过提供指导心脏血管重塑的靶点进行治疗。

In every form of heart disease, the secretion of extracellular matrix (ECM) by activated fibroblasts, or myofibroblasts, results in cardiac fibrosis. Fibrosis impedes compliance and pumping function, ultimately leading to heart failure due to left ventricular dilation and loss of mechanical function. Little is known about endothelial cell and vessel adaptations to the environment or how local mechanics and chemistry impact vessel structure and flow in vivo. Combinatorial fibroblast and ECM mechanical and chemical crosstalk with endothelial cells are unknown. Moreover, in vitro models aiming to assess vascular adaptations to an extracellular environment lack physiologically relevant ECMs and instead provide exogenous ECM components to optimize control of variables. A system for in vivo, cell-specific phenotypic manipulation will allow for controlled perturbations at an organ level while maintaining relevant, native ECM remodeling over time. Thus, I propose to examine transgenic mice with cardiac fibroblast-specific overexpression of a constitutively active mitogen-activated protein kinase kinase 6 (MKK6) to study vascular remodeling with respect to the fibroblasts and the ECM they secrete. These mice were previously shown to develop interstitial and perivascular fibrosis after 16-20 weeks of the MKK6 gene activation without an injury stimulus, serving as an effective model of the interstitial fibrosis preserved across the results of aging, hypertension, aortic stenosis, and other diseases of the heart. Importantly, the remodeling seen in these diseases does not involve a massive loss of cardiomyocytes, as in a myocardial infarction, but rather a conserved fibroblast phenotypic change, an altered extracellular space, and/or restricted vascular flow over time. Similarly, manipulation of the MKK6 pathway allows for overexpression or knockdown of cardiac fibroblast activation, corresponding to increased ECM or the inability to secrete ECM as a response to a stimulus, respectively. First, I propose to study the biochemical, structural, and mechanical properties of the ECM as well as the macro- and microvascular responses to activated, quiescent, and control cardiac fibroblast phenotypes in vivo. Second, three-dimensional vessel-like structures with controlled fibroblasts and ECMs will be engineered as in vitro platforms to define the molecular regulators of vascular remodeling induced by microenvironmental cues. The effects of combined signaling will be resolved by global characterization along with a reductionist method. The goal of this work is to inform heart therapies by providing targets for steering cardiac vascular remodeling.