Rho kinase (ROCK) is a serine/threonine protein kinase which functions as one of the downstream effectors for the small G-protein RhoA. The RhoA/ROCK pathway has an important role in mediating various cellular processes, including cytoskeletal remodeling, cell proliferation, and gene expression. More recently, the RhoA/ROCK pathway has emerged as a promising target in the treatment of coronary vasospasm, stroke, erectile dysfunction, and hypertension. In this proposal, we argue that ROCK also plays a critical role in the pathogenesis of diabetic nephropathy (DN) via its involvement in modulating the reactive oxygen species (ROS) signaling pathway. Our hypothesis is based on several novel observations: 1) RhoA/ROCK pathway is involved in glucose-induced signaling (Danesh FR et al. Proc. Natl. Acad. Sci. 2002), 2) Blockade of ROCK ameliorates progression of DN in the db/db model of type 2 diabetes (Kolavennu V et al. Diabetes 2007), and 3) our preliminary data suggesting that ROCK activation plays a pivotal role in both mitochondrial and NADPH redox signaling. Based upon these initial observations, we now propose an integrated in vitro and in vivo approach to test three specific aims.
Aim 1 : To test the hypothesis that at the cellular level, ROCK mediates the cross-talk between mitochondrial- and NADPH-derived ROS overproduction in the diabetic milieu.
Aim 2 : To test the hypothesis that selective inhibition of ROCK in the experimental models of type 1 and type 2 diabetes ameliorates the progression of DN by inhibiting ROCK-mediated ROS production.
Aim 3 : To test the effect of tissue-specific conditional gene targeting of ROCK in DN. The findings of this application will provide a significant advance in three aspects: first, the successful completion of this proposal is not only relevant to kidney research, but it will also provide a framework for understanding the spatial and temporal behavior of redox signaling. Second, it will assess the role of RhoA/ROCK signaling in the kidney. And third, it will lead to development of novel therapeutic strategies in DN.

Public Health Relevance

Diabetic nephropathy remains the leading cause of renal failure in the U.S. The current study will focus on a novel pathway possibly involved in the progression of diabetic kidney disease. We propose that inhibition of the RhoA/ROCK pathway holds promise as a novel therapeutic strategy to improve microvascular outcomes in diabetes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK078900-02
Application #
7762180
Study Section
Special Emphasis Panel (ZRG1-RUS-B (02))
Program Officer
Rys-Sikora, Krystyna E
Project Start
2009-02-01
Project End
2014-01-31
Budget Start
2010-02-01
Budget End
2011-01-31
Support Year
2
Fiscal Year
2010
Total Cost
$363,182
Indirect Cost
Name
Baylor College of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Galvan, Daniel L; Green, Nathanael H; Danesh, Farhad R (2017) The hallmarks of mitochondrial dysfunction in chronic kidney disease. Kidney Int 92:1051-1057
Galvan, Daniel L; Badal, Shawn S; Long, Jianyin et al. (2017) Real-time in vivo mitochondrial redox assessment confirms enhanced mitochondrial reactive oxygen species in diabetic nephropathy. Kidney Int 92:1282-1287
Badal, Shawn S; Wang, Yin; Long, Jianyin et al. (2016) miR-93 regulates Msk2-mediated chromatin remodelling in diabetic nephropathy. Nat Commun 7:12076
Long, Jianyin; Badal, Shawn S; Ye, Zengchun et al. (2016) Long noncoding RNA Tug1 regulates mitochondrial bioenergetics in diabetic nephropathy. J Clin Invest 126:4205-4218
Galvan, Daniel L; Danesh, Farhad R (2016) Paradoxical Role of IL-17 in Progression of Diabetic Nephropathy. J Am Soc Nephrol 27:657-8
Ayanga, Bernard A; Badal, Shawn S; Wang, Yin et al. (2016) Dynamin-Related Protein 1 Deficiency Improves Mitochondrial Fitness and Protects against Progression of Diabetic Nephropathy. J Am Soc Nephrol 27:2733-47
Badal, Shawn S; Danesh, Farhad R (2015) Diabetic Nephropathy: Emerging Biomarkers for Risk Assessment. Diabetes 64:3063-5
Badal, Shawn S; Danesh, Farhad R (2015) MicroRNAs and their applications in kidney diseases. Pediatr Nephrol 30:727-40
Badal, Shawn S; Danesh, Farhad R (2014) New insights into molecular mechanisms of diabetic kidney disease. Am J Kidney Dis 63:S63-83
Long, Jianyin; Badal, Shawn S; Wang, Yin et al. (2013) MicroRNA-22 is a master regulator of bone morphogenetic protein-7/6 homeostasis in the kidney. J Biol Chem 288:36202-14

Showing the most recent 10 out of 18 publications