Tubulointerstitial fibrosis is considered as a final common outcome of a wide range of chronic kidney diseases (CKD), regardless of the initial causes. The pathogenesis of interstitial fibrosis is a remarkably monotonous process characterized by de novo activation of the matrix-producing myofibroblasts. Evidence indicates that a large proportion of interstitial fibroblasts are actually originated from tubular epithelial cells via epithelial to mesenchymal transition (EMT). However, the mechanism underlying tubular EMT remains elusive. Studies from the applicant's laboratory demonstrate that integrin-linked kinase (ILK), an intracellular serine/threonine protein kinase that interacts with the cytoplasmic domains of (-integrins, plays an imperative role in mediating tubular EMT and renal interstitial fibrogenesis. The central hypotheses of this application are that: 1) ILK is a central element of a multi-component cellular machinery, and the function of ILK depends on its interactions with key partners; 2) ILK plays an imperative role in the maintenance of tubular cell phenotypes and matrix homeostasis in vivo; and 3) ILK is a prime molecular target for designing an effective therapy for chronic renal fibrosis. These hypotheses will be tested in the following four specific Aims.
Aim 1 is to investigate the ILK interactions with its partners and to elucidate their functional significance in mediating tubular EMT.
Aim 2 will delineate the role of PINCH, a key partner of ILK, in mediating tubular EMT and renal fibrosis.
Aim 3 is designed to investigate the physiologic and pathologic role of ILK in renal tubules in vivo by conditional knockout approach.
Aim 4 will evaluate the therapeutic efficacy of ILK inhibitor for renal interstitial fibrosis. These studies will not only provide mechanistic insights into understanding the regulation of tubular EMT in the setting of CKD, but also offer unique opportunities for designing rational strategies for the treatment of chronic renal fibrosis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK071040-03
Application #
7241478
Study Section
Pathobiology of Kidney Disease Study Section (PBKD)
Program Officer
Mullins, Christopher V
Project Start
2005-06-01
Project End
2009-05-31
Budget Start
2007-06-01
Budget End
2008-05-31
Support Year
3
Fiscal Year
2007
Total Cost
$251,097
Indirect Cost
Name
University of Pittsburgh
Department
Pathology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Liu, Youhua (2011) Cellular and molecular mechanisms of renal fibrosis. Nat Rev Nephrol 7:684-96
Wang, Dan; Dai, Chunsun; Li, Yingjian et al. (2011) Canonical Wnt/?-catenin signaling mediates transforming growth factor-?1-driven podocyte injury and proteinuria. Kidney Int 80:1159-1169
Dai, Chunsun; Wen, Xiaoyan; He, Weichun et al. (2011) Inhibition of proinflammatory RANTES expression by TGF-beta1 is mediated by glycogen synthase kinase-3beta-dependent beta-catenin signaling. J Biol Chem 286:7052-9
He, Weichun; Kang, Young Sun; Dai, Chunsun et al. (2011) Blockade of Wnt/ýý-catenin signaling by paricalcitol ameliorates proteinuria and kidney injury. J Am Soc Nephrol 22:90-103
He, Weichun; Tan, Ruoyun; Dai, Chunsun et al. (2010) Plasminogen activator inhibitor-1 is a transcriptional target of the canonical pathway of Wnt/beta-catenin signaling. J Biol Chem 285:24665-75
Hao, Sha; Shen, Hongmei; Hou, Yayi et al. (2010) tPA is a potent mitogen for renal interstitial fibroblasts: role of beta1 integrin/focal adhesion kinase signaling. Am J Pathol 177:1164-75
Liu, Youhua (2010) New insights into epithelial-mesenchymal transition in kidney fibrosis. J Am Soc Nephrol 21:212-22
Kang, Young Sun; Li, Yingjian; Dai, Chunsun et al. (2010) Inhibition of integrin-linked kinase blocks podocyte epithelial-mesenchymal transition and ameliorates proteinuria. Kidney Int 78:363-73
Dai, Chunsun; Saleem, Moin A; Holzman, Lawrence B et al. (2010) Hepatocyte growth factor signaling ameliorates podocyte injury and proteinuria. Kidney Int 77:962-73
Wen, Xiaoyan; Li, Yingjian; Liu, Youhua (2010) Opposite action of peroxisome proliferator-activated receptor-gamma in regulating renal inflammation: functional switch by its ligand. J Biol Chem 285:29981-8

Showing the most recent 10 out of 31 publications