Pilot & Feasibility Program Awardees

David Kaplan, PhD (Professor)
Years Funded: 2014-2015
Title: Human and mouse 3D models to study PKD/fibrosis and microperfusion
Institution: Tufts University

Justification: The proposed research will establish in vitro 3D tissue models to study hepatorenal fibrocystic diseases and related mechano-sensory signaling.   Establishing this system would be a major benefit for therapeutic screening.

Description/Progress: Polycystic kidney disease is a monogenic disorder that causes the development of bilateral focal cysts and severe fibrosis which ultimately result in renal failure and the need for renal replacement therapy. The goal of this research is to develop 3D mouse and human renal epithelial tissue models containing inducible diseased renal epithelial cells and fibroblasts. Additionally, we will develop “healthy” renal epithelial tissue models cultured under flow conditions with a confluent epithelial layer on a silk protein scaffold infused with an ECM hydrogel. The hypothesis is that these tissue models can be used to study disease progression, tissue repair after injury and how misregulation of repair leads to persistent renal damage. The developed models will allow us to monitor disease progression or multiple injury events over several months, desirable for disease studies and drug testing. Aim 1 will focus on renal fibrosis and PKD to develop combined in vitro 3D fibrosis/PKD models using human and mouse epithelial cells and fibroblasts cultured under static conditions. In Aim 2, a custom 3D perfusion culture system consisting of a porous silk protein scaffold will be developed to provide a system to study mechano-sensory cues. While establishing these two focus areas, we will develop/apply techniques to monitor fibrosis, cell-matrix interactions and phenotype changes associated with disease. These models will provide a framework for studying other kidney-related diseases, including ARPKD using mouse cells from the Oak Ridge Polycystic Kidney Disease mouse model.

Michele Pritchard, PhD  (Assistant Professor)
Years Funded: 2014-2015
Title: Role of hepatic mast cells in progression of CHF in ARPKD
Institution: University of Kansas

Justification: This study looks at whether mast cells (MC) contribute to CHF/ARPKD pathogenesis through degranulation, thereby allowing rapid translation of clinically approved MC stabilizing agents for use in CHF/ARPKD patients. Second, if MCs are important for proliferation and fibrosis in the CHF/ARPKD livers, then MCs will also play a pathogenic role in polycystic liver disease of other genetic etiologies, thus broadening the clinical utility of anti-MC therapeutic strategies.

Description/Progress: Congenital hepatic fibrosis in autosomal recessive polycystic kidney disease (CHF/ARPKD) is a serious medical condition for which few therapeutic strategies exist. Hepatic and renal disease in the PCK rat recapitulates human CHF/ARPKD due to mutations in a gene (Pck) orthologous to the human PKHD1 gene. Our preliminary data using the PCK rat revealed robust recruitment of mast cells (MC), innate immune effector cells, to the area immediately around the liver cysts. MC effector activity, which includes, in part, release of preformed mediators such as chymase, tryptase and histamine from large cytoplasmic granules into the extracellular environment, is responsible for MC-mediated effector function. Interestingly, the recruitment of MC into livers from PCK rats occurs concomitantly with a rapid increase in cyst number, liver to body weight ratio, markers associated with cyst wall epithelial cell (CWEC) proliferation, and expansion of pericystic fibrosis. This proposal was designed to test the hypothesis that MCs are essential for CWEC proliferation (Aim 1) and pericysitc fibrosis (Aim 2). We will test these hypotheses through pharmacologic manipulation of MC granule release. Specifically, we will prevent MC degranulation using the MC stabilizer, cromolyn sodium, and force MC degranulation using compound 48/80 in PCK rats, and then assess the effects these manipulations have on CWEC proliferation and pericystic fibrosis. If MC degranulation contributes to disease pathogenesis, then rapid translation of FDA-approved MC stabilizers such as cromolyn sodium for use in CHF patients will be possible, providing a significant advance in the therapeutic management for CHF/ARPKD patients.