The kidney, like many epithelial organs, consists mainly of tubules lined by a monolayer of polarized epithelial cells. Though we have learned a great deal about the genes that control kidney development, we know much less about the mechanisms by which cells rearrange themselves into tubules. Weuse a simplified model system of Madin-Darbycanine kidney (MDCK) cells grown in a 3 dimensionalcollagen gel. Single MDCK cellsgrow to form hollow cysts lined by a monolayer of epithelial cells. When these cysts are stimulated with Hepatocyte Growth Factor (HGF), they form tubules over a period of ~3 days. This is a good model system for studying renal tubule formation, and can also provide informationon several pathophysiological processes, such as recovery from acute tubular necrosis, renal fibrosis, polycystickidney disease and perhaps renal regeneration from stem cells.We will study the signaling pathways by which cells respond to HGF. The kinetics of activation of ERKsuggest that it is activated by a MAPK cascadeinvolving B-Raf, rather than the better known Raf-1. We will test this hypothesis by studying activation of components of the B-Raf pathway and by using dominant negatives and RNAi. We will test the involvement of Rho family GTPases, Rho Kinase and lipid rafts in the early stages of tubulogenesis, especially the formation of extensions from the basolateral surface of cells in cysts. We will use time lapse confocal microscopy to observe the effects of perturbing these molecular components on extension formation.We will test the involvement of phosphatidyl inositol (3,4,5)P3 [PI(3,4,5)P3]in extension formation. We have found that exogenous PI(3,4,5)P3 induces extension formation and we will test if these extensions are identical to those produced by HGF. We will analyze possible effectors of PI(3,4,5)P3. Kidney diseases, including developmental defects, kidney injury and genetic conditions that form multiple cysts in the kidney, are major health problems. The kidney consists of many narrow tubes lined by cells. We are using a simple model system where kidney cells are grown in culture and produce such tubes, to study tube formation and how we can influence this to treat and prevent kidney diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK074398-02
Application #
7337382
Study Section
Cellular and Molecular Biology of the Kidney Study Section (CMBK)
Program Officer
Hoshizaki, Deborah K
Project Start
2007-01-01
Project End
2010-11-30
Budget Start
2007-12-01
Budget End
2008-11-30
Support Year
2
Fiscal Year
2008
Total Cost
$252,902
Indirect Cost
Name
University of California San Francisco
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
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Gao, Lei; Yang, Zhufeng; Hiremath, Chitkale et al. (2017) Afadin orients cell division to position the tubule lumen in developing renal tubules. Development 144:3511-3520
Datta, Anirban; Sandilands, Emma; Mostov, Keith E et al. (2017) Fibroblast-derived HGF drives acinar lung cancer cell polarization through integrin-dependent RhoA-ROCK1 inhibition. Cell Signal 40:91-98
Kwon, Sang-Ho; Oh, Sekyung; Nacke, Marisa et al. (2016) Adaptor Protein CD2AP and L-type Lectin LMAN2 Regulate Exosome Cargo Protein Trafficking through the Golgi Complex. J Biol Chem 291:25462-25475
Nedvetsky, Pavel I; Zhao, Xiaocheng; Mathivet, Thomas et al. (2016) cAMP-dependent protein kinase A (PKA) regulates angiogenesis by modulating tip cell behavior in a Notch-independent manner. Development 143:3582-3590
Peng, Juan; Awad, Aline; Sar, Sokhavuth et al. (2015) Phosphoinositide 3-kinase p110? promotes lumen formation through the enhancement of apico-basal polarity and basal membrane organization. Nat Commun 6:5937
Kim, Minji; M Shewan, Annette; Ewald, Andrew J et al. (2015) p114RhoGEF governs cell motility and lumen formation during tubulogenesis through a ROCK-myosin-II pathway. J Cell Sci 128:4317-27
Nedvetsky, Pavel I; Emmerson, Elaine; Finley, Jennifer K et al. (2014) Parasympathetic innervation regulates tubulogenesis in the developing salivary gland. Dev Cell 30:449-62
Bryant, David M; Roignot, Julie; Datta, Anirban et al. (2014) A molecular switch for the orientation of epithelial cell polarization. Dev Cell 31:171-87
Tran, Cindy S; Eran, Yoni; Ruch, Travis R et al. (2014) Host cell polarity proteins participate in innate immunity to Pseudomonas aeruginosa infection. Cell Host Microbe 15:636-43

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