Progressive kidney disease is characterized by the accumulation of fibrotic mediators in the kidney. Glomerulonephritis, diabetic nephropathy, pyelonephritis, and renovascular disease together account for over 75% of patients requiring renal transplants. In these conditions it is chronic progressive renal fibrosis with associated loss of functioning nephrons that results in irreversible renal injury. While the renin angiotensin system (RAS) has traditionally been viewed as a circulating axis, evidence is accumulating that an active intrarenal RAS plays an important role in chronic kidney disease and fibrosis. Based on recent evidence reported from our lab that mast cells express and release active renin, we hypothesize that renin released from mast cells infiltrating the kidney triggers intra-renal RAS and local angiotensin (ANG II) formation. The overall objective of this proposal is addressing the important issue of whether infiltrating mast cells and mast-cell renin, play a significant role in ischemic organ damage and fibrosis. Using a model of progressive renal fibrosis (unilateral ureteral obstruction (DUO)) we will study the role of mast cell renin and local ANG II production in this process as well as investigate the role of adenosine in regulating mast cell renin gene expression. Our preliminary results demonstrate: 1. Human and rodent kidney mast cells express active renin. 2. Mast cell deficient mice do not develop renal fibrosis with UUO 3. Stabilizing mast cells in rat UUO kidney prevents renal fibrosis. 4. Inhibiting the renin released from mast cells reduces vasoconstriction in isolated and perfused kidney. 5. Stimulating the adenosine A2b receptor increases mast cell renin gene expression.
In Specific Aim I. we will characterize the molecular identity of mast cell renin and examine the effects of mast cell renin and local ANG II formation on fibrosis and vasoconstriction in UUO. These experiments will be done with mast cells isolated from human and rodent kidney and with HMC-1 cells, a cultured cell model of human mast cells. The UUO animal studies will be carried out in rat and mast cell- deficient c-Kit knockout mice and their congenic controls.
Specific Aim II. will examine regulation of mast cell renin expression, synthesis, and release by adenosine. These experiments will be done with isolated human kidney mast cells and with HMC-1 cells. If our hypothesis is proven correct then we will have identified a novel therapeutic target (mast cell renin) for ameliorating renal function in chronic kidney disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
3R01DK060726-07S1
Application #
7849380
Study Section
Pathobiology of Kidney Disease Study Section (PBKD)
Program Officer
Flessner, Michael Francis
Project Start
2001-12-01
Project End
2011-06-30
Budget Start
2009-07-01
Budget End
2010-06-30
Support Year
7
Fiscal Year
2009
Total Cost
$67,593
Indirect Cost
Name
Weill Medical College of Cornell University
Department
Physiology
Type
Schools of Medicine
DUNS #
060217502
City
New York
State
NY
Country
United States
Zip Code
10065
O'Connor, Nathan; Silver, Randi B (2013) Ratio imaging: practical considerations for measuring intracellular Ca2+ and pH in living cells. Methods Cell Biol 114:387-406
Veerappan, Arul; Reid, Alicia C; O'Connor, Nathan et al. (2012) Mast cells are required for the development of renal fibrosis in the rodent unilateral ureteral obstruction model. Am J Physiol Renal Physiol 302:F192-204
Veerappan, Arul; Reid, Alicia C; Estephan, Racha et al. (2008) Mast cell renin and a local renin-angiotensin system in the airway: role in bronchoconstriction. Proc Natl Acad Sci U S A 105:1315-20
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O'Connor, Nathan; Silver, Randi B (2007) Ratio imaging: practical considerations for measuring intracellular Ca2+ and pH in living cells. Methods Cell Biol 81:415-33
Reid, Alicia C; Silver, Randi B; Levi, Roberto (2007) Renin: at the heart of the mast cell. Immunol Rev 217:123-40
Mackins, Christina J; Kano, Seiichiro; Seyedi, Nahid et al. (2006) Cardiac mast cell-derived renin promotes local angiotensin formation, norepinephrine release, and arrhythmias in ischemia/reperfusion. J Clin Invest 116:1063-70
Seyedi, Nahid; Mackins, Christina J; Machida, Takuji et al. (2005) Histamine H3-receptor-induced attenuation of norepinephrine exocytosis: a decreased protein kinase a activity mediates a reduction in intracellular calcium. J Pharmacol Exp Ther 312:272-80
Silver, Randi B; Reid, Alicia C; Mackins, Christina J et al. (2004) Mast cells: a unique source of renin. Proc Natl Acad Sci U S A 101:13607-12

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