The reported incidence of acute kidney injury (AKI) varies from 5% in all hospitalized patients to 30-50% in intensive care units. Following acute injury, the kidney possesses a remarkable, but not inexhaustible capacity to repair itself. The factors stimulating this repair, and the source and role of autocrine, paracrine and/or endocrine growth factors in mediating the epithelial proliferation and repair remain uncertain. Numerous studies have indicated that infiltrating cells play an important role in the initiation and propagation of the tubule dysfunction and structural injury. The role of macrophages is of particular interest because they can exhibit distinctly different functional phenotypes, broadly characterized as proinflammatory (M1 or """"""""classically activated"""""""") and tissue reparative (M2 or """"""""alternatively activated"""""""") phenotypes. Macrophage infiltration is seen within one hour of reperfusion in ischemia/reperfusion models. These macrophages infiltrating early after ischemia/reperfusion injury have a distinct phenotype consistent with """"""""inflammatory"""""""" or """"""""M1"""""""" macrophages. Macrophages are one source of proinflammatory cytokines such as IL-1, IL-6 and TNF-? that are detected following AKI. Depletion of monocytes prior to ischemia/reperfusion injury provides significant functional and structural protection. In contrast, there is increasing evidence that monocyte-derived cells may play an essential role in tissue repair in other organs and recent data suggest an important role in repair following acute kidney injury. We propose that there is an important role for resident macrophages and dendritic cells to mediate recovery from acute tissue injury. Resident macrophages and tissue dendritic cells demonstrate significant overlap in surface marker expression with M2 macrophages. The overall questions to be addressed are: What are the relative roles of infiltrating macrophages vs. resident macrophages and/or dendritic cells in recovery from AKI and what are the signals and mechanisms by which these monocyte-derived cells promote renal epithelial cell repair? To answer these questions, we propose three specific aims:
Specific Aim I will determine the mechanisms by which renal macrophages/dendritic cells increase in response to acute kidney injury;
Specific Aim 2 will determine the role of resident macrophage/dendritic cell phagocytosis of apoptotic cells (""""""""Efferocytosis"""""""") in promoting epithelial regeneration after AKI;
Specific Aim II will determine mechanisms by which resident macrophages/dendritic cells stimulate epithelial cell regeneration. We propose that these studies will provide new and important insights into mechanisms of renal epithelial repair following acute injury and may lead to development of new treatment modalities for AKI, which are greatly needed.

Public Health Relevance

The proposed studies will investigate the role of resident renal macrophages and dendritic cells in the mediation of recovery from acute kidney injury. The studies will investigate mechanisms by which this population of cells may expand in response to acute injury and the mechanisms by which these cells mediate nephron cell regeneration, examining their roles to phagocytose apopototic cells, inhibit inflammation and secrete pro-proliferative cytokines and growth factors.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
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Special Emphasis Panel (KMBD)
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Rys-Sikora, Krystyna E
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Vanderbilt University Medical Center
Internal Medicine/Medicine
Schools of Medicine
United States
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Chiba, Takuto; Skrypnyk, Nataliya I; Skvarca, Lauren Brilli et al. (2016) Retinoic Acid Signaling Coordinates Macrophage-Dependent Injury and Repair after AKI. J Am Soc Nephrol 27:495-508
Perrien, Daniel S; Saleh, Mohamed A; Takahashi, Keiko et al. (2016) Novel methods for microCT-based analyses of vasculature in the renal cortex reveal a loss of perfusable arterioles and glomeruli in eNOS-/- mice. BMC Nephrol 17:24
Nlandu Khodo, Stellor; Neelisetty, Surekha; Woodbury, Luke et al. (2016) Deleting the TGF-β receptor in proximal tubules impairs HGF signaling. Am J Physiol Renal Physiol 310:F499-510
Cheng, Huifang; Fan, Xiaofeng; Lawson, William E et al. (2015) Telomerase deficiency delays renal recovery in mice after ischemia-reperfusion injury by impairing autophagy. Kidney Int 88:85-94
Zhang, Ming-Zhi; Yao, Bing; Wang, Yinqiu et al. (2015) Inhibition of cyclooxygenase-2 in hematopoietic cells results in salt-sensitive hypertension. J Clin Invest 125:4281-94
Wang, Yinqiu; Chang, Jian; Yao, Bing et al. (2015) Proximal tubule-derived colony stimulating factor-1 mediates polarization of renal macrophages and dendritic cells, and recovery in acute kidney injury. Kidney Int 88:1274-1282
Chang, Jian; Vacher, Jean; Yao, Bing et al. (2015) Prostaglandin E receptor 4 (EP4) promotes colonic tumorigenesis. Oncotarget 6:33500-11
Chen, Jianchun; Chen, Jian-Kang; Harris, Raymond C (2015) EGF receptor deletion in podocytes attenuates diabetic nephropathy. J Am Soc Nephrol 26:1115-25
Jiang, Li; Cheng, Qi; Zhang, Bin-Hao et al. (2015) Circulating microRNAs as biomarkers in hepatocellular carcinoma screening: a validation set from China. Medicine (Baltimore) 94:e603
Neelisetty, Surekha; Alford, Catherine; Reynolds, Karen et al. (2015) Renal fibrosis is not reduced by blocking transforming growth factor-β signaling in matrix-producing interstitial cells. Kidney Int 88:503-14

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