Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder that causes the development of bilateral focal cysts which ultimately result in renal failure and the need for renal replacement therapy such as dialysis or transplantation. Considering the disease affects over 600,000 people in the United States patients with ADPKD account for approximately 4% of all renal replacement therapy. Although the disease is associated with a mutation of either PKD1 (85% of cases) or PKD2 (15% of cases), there is a high level of variability between patients with respect to onset of cyst formation and disease severity. Due to a limited understanding of the disease pathogenesis there are no specific treatments for ADPKD and there is currently a lack of in vitro tissue models capable of elucidating the mechanisms behind cyst development. The goal of this project is to develop a 3D microperfusion model of ADPKD as a completely novel approach for investigating cytogenesis. The proposed methodology is a unique combination of tissue engineering and microfluidics which enables studies of cyst formation in response to mechanosensory cues, such as fluid flow, that is unattainable in current approaches. Fluid flow within this system can be used to evaluate the response of the tissue to changes in flow associated with renal injury and to introduce conditions mimicking renal repair. To achieve these goals a custom 3D perfusion system consisting of a microscale channel in a porous silk protein scaffold will be developed to provide the appropriate cell environment (aim 1a). A 3D in vitro human kidney tubule ADPKD disease model developed to have a controllable knockdown of PKD1 will be incorporated into the perfusion system for a comparison of normal and diseased tissues under perfusion and static conditions (aim 1b). The response of the normal and diseased tissues to injury based changes in fluid flow and subsequent repair stimulation will be characterized (aim 2). It is hypothesized that the forces mimicking injury will ultimately result in increased cell proliferation and cyst formation in the ADPKD model as the result of aberrant activation of affiliated pathways such as mTOR and STAT6. An increased understanding of the cellular pathways and external forces associated with cyst formation will ultimately assist in the development of targeted treatments for the disease. The structure of this proposal requires concurrent training in a diverse skill set including cell and molecular biology, biomaterials desig and engineering and bioreactor design and implementation and imaging. The diversity of research within the Kaplan lab provides the appropriate environment for pursuing the above proposal and desired training.
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a hereditary disease that affects over 600,000 people in the United States and due to the disease severity a majority of patients requires regular kidney dialysis or kidney transplantation. Although scientists know the genetic mutations that cause the disease there are no specific treatments available due to a limited understanding of how the disease develops in the body. An increased understanding of the disease requires the development of diseased tissue models that can be studied and controllably manipulated in a laboratory setting and the subsequent findings can be used to develop a treatment for the disease which currently lacks one.