Defining the molecular landscape of hyperfiltration-mediated glomerular injury using kidney allografts as a model system

点击翻译按钮获取中文摘要

ABSTRACT: Long-term kidney allograft survival has not improved significantly over the last two decades. Accumulating data supports the hypothesis that progressive glomerular disease drives late kidney allograft failure, with hyper- filtration mediated glomerular injury being a putative driver. In addition, hyperfiltration is implicated in the progres- sion of kidney diseases such as in diabetes and obesity, both of which have reached epidemic proportions. How- ever, the molecular underpinnings of this shared mechanism of kidney disease progression remain unclear and forms the scientific basis of this proposal. My long-term goal is to understand disease mechanisms driving late allograft loss, with a focus on prolonging allograft lifespan. The overall objective of this application is to elucidate the molecular mechanisms by which hyperfiltration initiates and drives the podocyte detachment process in kidney allografts. We will also test whether parallel mechanisms are operating in an independent cohort of hyperfiltering diabetic patients. Towards achieving this objective my central hypothesis is that hyperfiltration leads to a characteristic molec- ular footprint in the glomerulus that drives podocyte stress and accelerated detachment. To identify the underlying molecular mechanism of hyperfiltration, a combination of bulk- and single cell RNA-sequencing technology will be used to identify glomerular cell-specific gene signatures as well as interactions between cells associated with the glomerular basement membrane that are known to drive podocyte detachment. To enable non-invasive mon- itoring of podocyte loss, we will use urine pellet podocyte detachment assays and measure hyperfiltration using filtration fraction studies. We will test the central hypothesis using three specific aims: Aim 1. Define the glomerular transcriptional response to hyperfiltration. Aim 2. Define the glomerular transcriptional profile that drives accelerated podocyte detachment and identify the effect of hyperfiltration on this relationship. Aim 3: Define the relationship of allograft hyperfiltration with podocyte stress and detachment. The research is innovative as it uses human kidney allografts as a model system to focus on hyperfiltration as a common mechanism of kidney disease progression analyzed by state-of-the-art technologies. The proposed research is significant as the identification of shared pathways of disease progression between kidney diseases could lead to the development of novel targeted therapeutic agents and non-invasive monitoring strategies. Ulti- mately, such knowledge will be crucial to slow down kidney disease progression regardless of its etiology.