Research Project 2: Molecular analysis of developing post-natal mouse kidney in health and FSGS

摘要 出生后，肾脏在小鼠体内持续发育数周，在人类体内持续发育数月至数年。在.期间 这一时期，出生后的肾脏正在经历生长和成熟，这需要动态变化的肾脏 基因表达、新陈代谢和生理功能，并容易受到侮辱，造成永久性 形态变化和功能适应。出生后肾脏的生长和成熟起着重要作用 在发育性程序性疾病中的重要作用。例如，出生时有适度减少的儿童 肾单位数可能对代谢应激更敏感，如高脂肪或高盐饮食、肥胖和 因缺氧或肾毒素造成的肾脏损伤。许多研究已经生成了胎儿和成人的单细胞数据集 老鼠肾。然而，尽管产后侮辱在先天性心脏病的发生和发展中起着重要的作用 CKD，出生后肾脏的成熟还没有在分子水平上进行全面的研究。 使用最先进的技术。缺乏这一关键发展时期的参考地图集限制了我们 在儿童肾脏疾病模型中研究细胞状态变化和多样性的能力。 肾小球疾病，包括肾病综合征，是儿童肾脏疾病的重要原因。 疾病。局灶性和节段性肾小球硬化(FSGS)是一种频率越来越高的诊断，是 经常复发和治疗耐药，并导致终末期肾病。继发性肾小球硬化 蛋白尿发生在影响儿童的常见非肾小球疾病中，如CAKUT，并预示 进展为终末期肾功能衰竭的风险更高。目前，用于治疗的治疗选择有限。 这些疾病以及更好地了解疾病机制的迫切需要。其中一个主要机制是 细胞对压力或伤害的反应是通过利用染色质修饰机制对基因进行重新编程 监管网络。我们开发了一种新的由于转移功能丧失而导致的FSGS小鼠模型 相关蛋白2(Mta2)，NuRD染色质重塑复合体的核心成分。这些突变体 小鼠是一个很好的模型，可以用来研究临床上无症状的肾单位捐赠缺陷和 细胞分化改变可在青春期晚期/成年期早期表现为FSGS。 在这个方案中，我们将生成一个整合的单细胞和空间转录小鼠图谱 (PKidCAP)在出生后的时间点，与主要的生理和发育变化相吻合 肾脏。我们将确定细胞多样性、空间定位、单细胞基因表达的演变 健康和FSGS组织中发育中的出生后肾脏的特征和染色质可及性状态。 我们将应用芯片序列和表观基因组编辑来检验假设Jun/AP-1靶标在 Mta2突变体可促进炎症、细胞衰老和脂毒性。将这些数据集与 人类pKidCAP图谱(项目1)将创建一个独特的参考小组来识别在鼠标中发现的路径 与儿童肾脏疾病高度相关的模型。

Summary After birth, the kidney continues to develop for weeks in mice, and for months to years in humans. During this period, the post-natal kidney is undergoing growth and maturation, which requires dynamic changes in gene expression, metabolism, and physiological functions, and is susceptible to insults causing permanent morphological changes and functional adaptation. Post-natal growth and maturation of the kidney play an important role in developmentally programmed diseases. For e.g., children born with a moderate reduction in nephron number may be more sensitive to metabolic stresses, such as high fat or high salt diet, obesity, and renal injury from hypoxia or nephrotoxins. Many studies have generated single cell datasets for fetal and adult mouse kidney. However, in spite of the important role of post-natal insults in development and progression of CKD, post-natal maturation of the kidney has not been comprehensively investigated at the molecular level using state-of-the-art technologies. The lack of a reference atlas for this critical developmental period limits our ability to investigate alterations in cell states and diversity in models of pediatric kidney disease. Glomerular diseases, including nephrotic syndrome, represent an important cause of childhood kidney disease. Focal and segmental glomerulosclerosis (FSGS) is a diagnosis that is increasing in frequency, is often recurrent and treatment resistant, and leads to end stage kidney disease. Secondary glomerulosclerosis and albuminuria develop in common non-glomerular diseases affecting children, such as CAKUT, and portend a higher risk of progression to end stage kidney failure. Currently, there are limited therapeutic options to treat these disorders and a pressing need to better understand disease mechanisms. One of the major mechanisms by which cells respond to stress or injury is by utilizing the chromatin modifying machinery to reprogram gene regulatory networks. We developed a novel mouse model of FSGS due to loss of function of metastases associated protein 2 (Mta2), a core component of the NuRD chromatin remodeling complex. These mutant mice represent an excellent model to investigate how clinically silent defects in nephron endowment and altered cell differentiation can manifest as FSGS in late adolescence/early adulthood. In this proposal we will generate an integrated single cell and spatial transcriptomics mouse atlas (pKidCAP) at post-natal timepoints that coincide with major physiological and developmental changes in the kidney. We will determine the evolution of cell diversity, spatial localization, single cell gene expression signatures and chromatin accessibility states in the developing post-natal kidney in healthy and FSGS tissue. We will apply ChIP-seq and epigenomic editing to test the hypothesis that de-repression of Jun/AP-1 targets in Mta2 mutants promotes inflammation, cell senescence and lipotoxicity. Integration of these datasets with the human pKidCAP atlas (Project 1) will create a unique reference panel to identify pathways uncovered in mouse models that are highly relevant to kidney diseases in children.