Therapeutic strategies and molecular mediators of renal pathology in cardiorenal syndrome type 2

心脏和肾脏功能障碍经常共存，形成一种病理生理循环，对短期和长期的发病率和死亡率产生不利影响。临床实体心肾综合征（CRS）描述心脏和肾脏的联合功能障碍。CRS 2型以慢性心力衰竭引起进行性慢性肾脏疾病（CKD）为特征，被认为是CRS最常见的亚型。在心力衰竭的情况下，肾功能恶化会显著增加不良后果，但减缓CKD进展和预防终末期肾病的治疗选择是有限的，需要扩大。虽然血流动力学参数（如灌注不足和肾充血）的影响被讨论为CRS 2型CKD发展的驱动力，但对CRS 2型CKD发病和进展相关的非血流动力学途径知之甚少。本项目旨在建立细胞外囊泡（EV）依赖的器官间通讯的作用，通过microRNA （miRNA）从心脏转移到肾细胞，作为与CRS 2型肾脏病理相关的非血流动力学因素，并探讨其治疗意义。该项目的基本假设是慢性心力衰竭条件下的心肌细胞分泌含有mirna的ev，这些mirna靶向肾成纤维细胞和周细胞，诱导肌成纤维细胞转分化并促进肾纤维形成。为了解决这一假设，我们设定了以下目标：（目标1）血管紧张素II治疗的心肌细胞来源的ev以及慢性心力衰竭小鼠的血清来源的ev在体内和体外对肾靶细胞（成纤维细胞和周细胞）的肌成纤维细胞转分化能力进行了表征和分析。通过体内成像系统（IVIS）和转基因诱导型绿色荧光蛋白（GFP） EV报告小鼠品系检测的荧光标记EV细胞培养物将用于体内肾靶细胞的鉴定。（目的2）模拟CRS 2型的主动脉横缩（TAC）模型将用于鉴定候选EV miRNAs（小RNA测序），这些miRNAs先于或伴随心功能、结构和组成的病理变化。（目的3）此外，Thomas Thums团队最近发现的先前存在的化合物，如石蒜碱，将因其抗纤维化能力而被测试其在原发性肾脏疾病和CRS 2型中的治疗潜力。

Cardiac and renal dysfunction frequently coexist and form a pathophysiological cycle with an adverse impact on short- and long-term morbidity and mortality. The clinical entity cardiorenal syndrome (CRS) describes the combined dysfunction of the heart and the kidney. CRS type 2 is characterized by chronic heart failure causing progressive chronic kidney disease (CKD) and recognized as the most frequent subtype of CRS. Worsening kidney function in the context of heart failure significantly increases adverse outcomes, but therapeutic options to slow progression of CKD and prevent end-stage renal disease are limited and in need for expansion. While the impact of hemodynamic parameters such as hypoperfusion and renal congestion are discussed as driving forces for the development of CKD in CRS type 2, little is known about the non-hemodynamic pathways relevant for the onset and progression of CKD in CRS type 2. This project aims to establish the role of extracellular vesicle (EV) dependent interorgan communication by microRNA (miRNA) transfer from cardiac to renal cells as a non-hemodynamic factor relevant for the renal pathology in CRS type 2 and to explore its therapeutic implications. The underlying hypothesis for this project is that cardiomyocytes under conditions of chronic heart failure secrete EVs containing miRNAs that target renal fibroblasts and pericytes which induce myofibroblast transdifferentiation and promote renal fibrogenesis. The following aims are set to address this hypothesis: (Aim 1) angiotensin II treated cardiomyocyte derived EVs as wells as serum derived EVs from mice suffering chronic heart failure are characterized and analyzed for the capacity of myofibroblast transdifferentiation of renal target cells (fibroblasts and pericytes) in vitro and in vivo. Cell culture derived fluorescently labeled EVs detected by in vivo imaging system (IVIS) and transgenic inducible green fluorescent protein (GFP) EV reporter mouse strains will be used to identify renal target cells in vivo. (Aim 2) The transverse aortic constriction (TAC) model mimicking CRS type 2 will be used to identify candidate EV miRNAs (small RNA sequencing) that precede or accompany pathologic changes in renal function, structure and composition in response to heart insufficiency. (Aim 3) In addition, preexisting compounds such as lycorine, that has been recently identified by Thomas Thums´ group, will be tested for its therapeutic potential in primary renal disease as well as CRS type 2 due to its antifibrotic capacity.