The objective of this K99/R00 application is to utilize a new animal model system that I have developed for the study of molecular mechanisms of nephrotic syndrome and podocyte regeneration. This will aid the transition of my research career toward an independent investigator position. Nephrotic syndrome (NS) is a kidney disease characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia, due to the disruption of renal glomerular filtration barrier (GFB) function. The causes of over 75% of steroid resistant nephrotic syndrome (SRNS) cases are still unknown and no effective therapy is available for the disease, which results in focal segmental glomerular sclerosis (FSGS) and leads to end-stage kidney disease (ESKD). Recent discoveries of genetic causes of SRNS and studies of rodent models of podocyte damage revealed the pivotal role of podocytes in the normal function of GFB and the pathogenesis of NS. However, rodent models for NS are not suitable for high-throughput screening of therapeutical agents for the disease. Recent studies have identified a subset of renal progenitor cells in adult human kidney that are capable of regenerating renal epithelial cells, including podocytes, suggesting a novel stem/progenitor cell-based approach for the treatment of nephrotic syndrome. However, little is known about the regenerative mechanism of podocytes. To address these questions, I propose to establish zebrafish mesonephros as a new model system for nephrotic syndrome by: (1) utilizing the transgenic zebrafish models that I have generated to screen for chemicals ameliorating proteinuria;(2) investigating the potential of wt1b-expressing renal progenitor cell to regenerate podocytes in zebrafish and gene expression during podocyte regeneration;(3) using the established GFB assay(s) to screen for temperature-sensitive nephrotic zebrafish mutants and identify novel genetic causes of NS. Accomplishment of the proposed research will provide (1) new chemical compounds that can lead to therapies for NS;(2) new insights into the mechanism of podocyte regeneration;(3) new genes that are involved in the pathogenesis of NS;and (4) new zebrafish models for the disease. Being a postdoctoral research fellow in the Department of Pediatrics and Communicable Diseases, University of Michigan, I am committed to develop zebrafish mesonephros into a new animal model system for nephrotic syndrome as my immediate career goal. My long-term career goal is to establish myself as an independent investigator in the field of kidney research, focusing on animal models of kidney diseases. The training (K99) phase of this award will be mentored by Dr. Friedhelm Hildebrandt, who is an investigator of Howard Hughes Medical Institute and internationally recognized leader in the fields of human genetics of pediatric kidney diseases, including nephrotic syndrome. University of Michigan has dozens of active and collaborative research groups working on kidney development, kidney diseases, and zebrafish development and genetics, which provides an ideal environment for my training and career development.

Public Health Relevance

Renal glomerular diseases account for 90% of end-stage kidney disease at a cost of $20 billion per year in the US. Nephrotic syndrome is due to the defective glomerular filtration barrier. Recent studies reveal dysfunction of podocytes and renal progenitor cells play critical roles in renal glomerular pathogenesis. This notion suggests podocytes and renal progenitor cells as new therapeutical targets for the disease. Generation of new zebrafish models of nephrotic syndrome and podocyte injury, which are amenable for large-scale chemical and genetic screenings, will allow for studies of molecular mechanisms of glomerular pathogenesis and search for novel therapy for glomerular diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Transition Award (R00)
Project #
4R00DK091405-03
Application #
8630209
Study Section
Special Emphasis Panel (NSS)
Program Officer
Rasooly, Rebekah S
Project Start
2013-06-01
Project End
2016-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
3
Fiscal Year
2013
Total Cost
$249,000
Indirect Cost
$66,622
Name
University of Michigan Ann Arbor
Department
Pediatrics
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Hosono, Yasuyuki; Niknafs, Yashar S; Prensner, John R et al. (2017) Oncogenic Role of THOR, a Conserved Cancer/Testis Long Non-coding RNA. Cell 171:1559-1572.e20
Wan, Xiaoyang; Lee, Mi-Sun; Zhou, Weibin (2016) Dosage-dependent role of Rac1 in podocyte injury. Am J Physiol Renal Physiol 310:F777-F784
Chen, Z; Wan, X; Hou, Q et al. (2016) GADD45B mediates podocyte injury in zebrafish by activating the ROS-GADD45B-p38 pathway. Cell Death Dis 7:e2068
Wan, Xiaoyang; Chen, Zhaohong; Choi, Won-Il et al. (2016) Loss of Epithelial Membrane Protein 2 Aggravates Podocyte Injury via Upregulation of Caveolin-1. J Am Soc Nephrol 27:1066-75
Ma, Guolin; Wei, Ming; He, Lian et al. (2015) Inside-out Ca(2+) signalling prompted by STIM1 conformational switch. Nat Commun 6:7826
Schueler, Markus; Braun, Daniela A; Chandrasekar, Gayathri et al. (2015) DCDC2 mutations cause a renal-hepatic ciliopathy by disrupting Wnt signaling. Am J Hum Genet 96:81-92
Lee, Mi-Sun; Hwang, Kyu-Seok; Oh, Hyun-Woo et al. (2015) IFT46 plays an essential role in cilia development. Dev Biol 400:248-57
Zhao, Ming; Wan, Xiaoyang; Li, Yu et al. (2015) Multiplexed 3D FRET imaging in deep tissue of live embryos. Sci Rep 5:13991
Gee, Heon Yung; Zhang, Fujian; Ashraf, Shazia et al. (2015) KANK deficiency leads to podocyte dysfunction and nephrotic syndrome. J Clin Invest 125:2375-84
Zhao, Ming; Zhang, Han; Li, Yu et al. (2014) Cellular imaging of deep organ using two-photon Bessel light-sheet nonlinear structured illumination microscopy. Biomed Opt Express 5:1296-308

Showing the most recent 10 out of 21 publications