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Tan RJ, Zhou D, Liu Y. Signaling Crosstalk between Tubular Epithelial Cells and Interstitial Fibroblasts after Kidney Injury. KIDNEY DISEASES 2016; 2:136-144. [PMID: 27921041 DOI: 10.1159/000446336] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 04/20/2016] [Indexed: 01/09/2023]
Abstract
BACKGROUND A wide variety of kidney diseases ultimately lead to tubulointerstitial damage. The initial site of injury is usually the renal tubules, with activation of fibroblasts occurring later. Self-limited disease is characterized by transient cellular activation with timed deactivation and ultimately a return to normal functioning, whereas sustained responses characterize chronic disease and the development of irreversible fibrosis. The underlying molecular and cellular mechanisms of this cascade of events remain an area of active research. Current data overwhelmingly support a role for crosstalk between the tubular epithelium and the interstitial fibroblast that mediates both repair/regeneration and progressive disease. This epithelial-mesenchymal communication (EMC) is regulated by a variety of soluble ligands binding to cell surface receptors to induce intracellular signaling events. SUMMARY EMC is an important mechanism whereby tubular epithelium and fibroblasts/mesenchymal cells crosstalk to affect renal physiology and pathology. Numerous soluble factors such as sonic hedgehog, Wnt ligands, transforming growth factor-β, hepatocyte growth factor, connective tissue growth factor, and angiotensin II all participate in bidirectional EMC. Recent studies have also identified exosomes as a vehicle to mediate EMC during kidney injury. In general, while the short-term activity of EMC factors is renoprotective, prolonged activation of these factors leads to chronic disease and fibrosis. KEY MESSAGES The discovery of a complex and intricate system of communication between tubular cells and fibroblasts is a new paradigm in our understanding of renal fibrosis. An appreciation of both their regenerative and pathologic functions will inform the development and use of targeted therapeutic interventions.
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Affiliation(s)
- Roderick J Tan
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA
| | - Dong Zhou
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA
| | - Youhua Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA; State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, Guangzhou, China
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52
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Sussman CR. Tgf-β, Notch, and HGF weave a tangled web of kidney repair. Am J Physiol Renal Physiol 2016; 310:F744-F745. [PMID: 26864936 DOI: 10.1152/ajprenal.00050.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Caroline R Sussman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
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53
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Agarwal A, Dong Z, Harris R, Murray P, Parikh SM, Rosner MH, Kellum JA, Ronco C. Cellular and Molecular Mechanisms of AKI. J Am Soc Nephrol 2016; 27:1288-99. [PMID: 26860342 DOI: 10.1681/asn.2015070740] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In this article, we review the current evidence for the cellular and molecular mechanisms of AKI, focusing on epithelial cell pathobiology and related cell-cell interactions, using ischemic AKI as a model. Highlighted are the clinical relevance of cellular and molecular targets that have been investigated in experimental models of ischemic AKI and how such models might be improved to optimize translation into successful clinical trials. In particular, development of more context-specific animal models with greater relevance to human AKI is urgently needed. Comorbidities that could alter patient susceptibility to AKI, such as underlying diabetes, aging, obesity, cancer, and CKD, should also be considered in developing these models. Finally, harmonization between academia and industry for more clinically relevant preclinical testing of potential therapeutic targets and better translational clinical trial design is also needed to achieve the goal of developing effective interventions for AKI.
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Affiliation(s)
- Anupam Agarwal
- Division of Nephrology, and Nephrology Research and Training Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Georgia Regents University, Augusta, Georgia
| | - Raymond Harris
- Division of Nephrology, Department of Medicine, Vanderbilt University, Nashville, Tennessee
| | - Patrick Murray
- Department of Medicine, University College of Dublin, Dublin, Ireland
| | - Samir M Parikh
- Division of Nephrology and Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Mitchell H Rosner
- Department of Medicine, Nephrology Division, and the Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - John A Kellum
- Center for Critical Care Nephrology, Clinical Research, Investigation and Systems Modeling of Acute Illness Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Claudio Ronco
- Department of Nephrology, Dialysis, and Transplantation, San Bortolo Hospital, and the International Renal Research Institute, 36100 Vicenza, Italy
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54
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Nlandu Khodo S, Neelisetty S, Woodbury L, Green E, Harris RC, Zent R, Gewin L. Deleting the TGF-β receptor in proximal tubules impairs HGF signaling. Am J Physiol Renal Physiol 2016; 310:F499-510. [PMID: 26739889 DOI: 10.1152/ajprenal.00446.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/30/2015] [Indexed: 01/26/2023] Open
Abstract
Transforming growth factor-β (TGF-β) and hepatocyte growth factor (HGF) play key roles in regulating the response to renal injury but are thought to mediate divergent effects on cell behavior. However, how TGF-β signaling alters the response to HGF in epithelia, the key site of HGF signaling in the injured kidney, is not well studied. Contrary to our expectation, we showed that deletion of the TGF-β type II receptor in conditionally immortalized proximal tubule (PT) cells impaired HGF-dependent signaling. This reduced signaling was due to decreased transcription of c-Met, the HGF receptor, and the TGF-β-dependent c-Met transcription and increased response to HGF in PT cells were mediated by the Notch pathway. The interactions of TGF-β, HGF, and Notch pathways had biologically significant effects on branching morphogenesis, cell morphology, migration, and proliferation. In conclusion, epithelial TGF-β signaling promotes HGF signaling in a Notch-dependent pathway. These findings suggest that TGF-β modulates PT responses not only by direct effects, but also by affecting other growth factor signaling pathways.
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Affiliation(s)
- Stellor Nlandu Khodo
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Surekha Neelisetty
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Luke Woodbury
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Elizabeth Green
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Raymond C Harris
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee; Department of Molecular Physiology and Biophysics, Vanderbilt Medical Center, Nashville, Tennessee; Department of Medicine, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Roy Zent
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee; Department of Cancer Biology, Vanderbilt Medical Center, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee; Department of Medicine, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Leslie Gewin
- Department of Research, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee; and Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee;
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55
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Carneiro MFH, Morais C, Small DM, Vesey DA, Barbosa F, Gobe GC. Thimerosal induces apoptotic and fibrotic changes to kidney epithelial cells in vitro. ENVIRONMENTAL TOXICOLOGY 2015; 30:1423-1433. [PMID: 24942245 DOI: 10.1002/tox.22012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 05/28/2014] [Indexed: 06/03/2023]
Abstract
Thimerosal is an ethyl mercury-containing compound used mainly in vaccines as a bactericide. Although the kidney is a key target for mercury toxicity, thimerosal nephrotoxicity has not received the same attention as other mercury species. The aim of this study was to determine the potential cytotoxic mechanisms of thimerosal on human kidney cells. Human kidney proximal tubular epithelial (HK2) cells were exposed for 24 h to thimerosal (0-2 µM), and assessed for cell viability, apoptosis, and cell proliferation; expression of proteins Bax, nuclear factor-κB subunits, and transforming growth factor-β1 (TGFβ1); mitochondrial health (JC-1, MitoTracker Red CMXRos); and fibronectin levels (enzyme-linked immunosorbent assay). Thimerosal diminished HK2 cell viability and mitosis, promoted apoptosis, impaired the mitochondrial permeability transition, enhanced Bax and TGFβ1 expression, and augmented fibronectin secretion. This is the first report about kidney cell death and pro-fibrotic mechanisms promoted by thimerosal. Collectively, these in vitro results demonstrate that (1) thimerosal induces kidney epithelial cell apoptosis via upregulating Bax and the mitochondrial apoptotic pathway, and (2) thimerosal is a potential pro-fibrotic agent in human kidney cells. We suggest that new evidence on toxicity as well as continuous surveillance in terms of fibrogenesis is required concerning thimerosal use.
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Affiliation(s)
- Maria Fernanda Hornos Carneiro
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Do Café, s/n, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Christudas Morais
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
| | - David M Small
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
| | - David A Vesey
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
| | - Fernando Barbosa
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Do Café, s/n, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Glenda C Gobe
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
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Camarata TD, Weaver GC, Vasilyev A, Arnaout MA. Negative Regulation of TGFβ Signaling by Stem Cell Antigen-1 Protects against Ischemic Acute Kidney Injury. PLoS One 2015; 10:e0129561. [PMID: 26053644 PMCID: PMC4460127 DOI: 10.1371/journal.pone.0129561] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/10/2015] [Indexed: 12/22/2022] Open
Abstract
Acute kidney injury, often caused by an ischemic insult, is associated with significant short-term morbidity and mortality, and increased risk of chronic kidney disease. The factors affecting the renal response to injury following ischemia and reperfusion remain to be clarified. We found that the Stem cell antigen-1 (Sca-1), commonly used as a stem cell marker, is heavily expressed in renal tubules of the adult mouse kidney. We evaluated its potential role in the kidney using Sca-1 knockout mice submitted to acute ischemia reperfusion injury (IRI), as well as cultured renal proximal tubular cells in which Sca-1 was stably silenced with shRNA. IRI induced more severe injury in Sca-1 null kidneys, as assessed by increased expression of Kim-1 and Ngal, rise in serum creatinine, abnormal pathology, and increased apoptosis of tubular epithelium, and persistent significant renal injury at day 7 post IRI, when recovery of renal function in control animals was nearly complete. Serum creatinine, Kim-1 and Ngal were slightly but significantly elevated even in uninjured Sca-1-/- kidneys. Sca-1 constitutively bound both TGFβ receptors I and II in cultured normal proximal tubular epithelial cells. Its genetic loss or silencing lead to constitutive TGFβ receptor—mediated activation of canonical Smad signaling even in the absence of ligand and to KIM-1 expression in the silenced cells. These studies demonstrate that by normally repressing TGFβ-mediated canonical Smad signaling, Sca-1 plays an important in renal epithelial cell homeostasis and in recovery of renal function following ischemic acute kidney injury.
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Affiliation(s)
- Troy D. Camarata
- Leukocyte Biology & Inflammation Program, Renal Division and Department of Medicine Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Grant C. Weaver
- Leukocyte Biology & Inflammation Program, Renal Division and Department of Medicine Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Alexandr Vasilyev
- Leukocyte Biology & Inflammation Program, Renal Division and Department of Medicine Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - M. Amin Arnaout
- Leukocyte Biology & Inflammation Program, Renal Division and Department of Medicine Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- Center For Regenerative Medicine, Department of Medicine, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- * E-mail:
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57
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Varrier M, Forni LG, Ostermann M. Long-term sequelae from acute kidney injury: potential mechanisms for the observed poor renal outcomes. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:102. [PMID: 25887052 PMCID: PMC4361133 DOI: 10.1186/s13054-015-0805-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2015 and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/annualupdate2015. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.
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Affiliation(s)
- Matt Varrier
- Department of Critical Care & Nephrology, Guy's & St Thomas' Foundation Hospital, London, UK. .,King's College London, London, UK.
| | - Lui G Forni
- Department of Intensive Care Medicine, Royal Surrey County Hospital, Surrey Peri-operative Anesthesia Critical Care Collaborative Research group (SPACeR), Guildford, UK.
| | - Marlies Ostermann
- Department of Critical Care & Nephrology, Guy's & St Thomas' Foundation Hospital, London, UK. .,King's College London, London, UK.
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58
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White WE, Yaqoob MM, Harwood SM. Aging and uremia: Is there cellular and molecular crossover? World J Nephrol 2015; 4:19-30. [PMID: 25664244 PMCID: PMC4317625 DOI: 10.5527/wjn.v4.i1.19] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/28/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
Many observers have noted that the morphological changes that occur in chronic kidney disease (CKD) patients resemble those seen in the geriatric population, with strikingly similar morbidity and mortality profiles and rates of frailty in the two groups, and shared characteristics at a pathophysiological level especially in respect to the changes seen in their vascular and immune systems. However, whilst much has been documented about the shared physical characteristics of aging and uremia, the molecular and cellular similarities between the two have received less attention. In order to bridge this perceived gap we have reviewed published research concerning the common molecular processes seen in aging subjects and CKD patients, with specific attention to altered proteostasis, mitochondrial dysfunction, post-translational protein modification, and senescence and telomere attrition. We have also sought to illustrate how the cell death and survival pathways apoptosis, necroptosis and autophagy are closely interrelated, and how an understanding of these overlapping pathways is helpful in order to appreciate the shared molecular basis behind the pathophysiology of aging and uremia. This analysis revealed many common molecular characteristics and showed similar patterns of cellular dysfunction. We conclude that the accelerated aging seen in patients with CKD is underpinned at the molecular level, and that a greater understanding of these molecular processes might eventually lead to new much needed therapeutic strategies of benefit to patients with renal disease.
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59
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Xavier S, Vasko R, Matsumoto K, Zullo JA, Chen R, Maizel J, Chander PN, Goligorsky MS. Curtailing endothelial TGF-β signaling is sufficient to reduce endothelial-mesenchymal transition and fibrosis in CKD. J Am Soc Nephrol 2014; 26:817-29. [PMID: 25535303 DOI: 10.1681/asn.2013101137] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Excessive TGF-β signaling in epithelial cells, pericytes, or fibroblasts has been implicated in CKD. This list has recently been joined by endothelial cells (ECs) undergoing mesenchymal transition. Although several studies focused on the effects of ablating epithelial or fibroblast TGF-β signaling on development of fibrosis, there is a lack of information on ablating TGF-β signaling in the endothelium because this ablation causes embryonic lethality. We generated endothelium-specific heterozygous TGF-β receptor knockout (TβRII(endo+/-)) mice to explore whether curtailed TGF-β signaling significantly modifies nephrosclerosis. These mice developed normally, but showed enhanced angiogenic potential compared with TβRII(endo+/+) mice under basal conditions. After induction of folic acid nephropathy or unilateral ureteral obstruction, TβRII(endo+/-) mice exhibited less tubulointerstitial fibrosis, enhanced preservation of renal microvasculature, improvement in renal blood flow, and less tissue hypoxia than TβRII(endo+/+) counterparts. In addition, partial deletion of TβRII in the endothelium reduced endothelial-to-mesenchymal transition (EndoMT). TGF-β-induced canonical Smad2 signaling was reduced in TβRII(+/-) ECs; however, activin receptor-like kinase 1 (ALK1)-mediated Smad1/5 phosphorylation in TβRII(+/-) ECs remained unaffected. Furthermore, the S-endoglin/L-endoglin mRNA expression ratio was significantly lower in TβRII(+/-) ECs compared with TβRII(+/+) ECs. These observations support the hypothesis that EndoMT contributes to renal fibrosis and curtailing endothelial TGF-β signals favors Smad1/5 proangiogenic programs and dictates increased angiogenic responses. Our data implicate endothelial TGF-β signaling and EndoMT in regulating angiogenic and fibrotic responses to injury.
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Affiliation(s)
- Sandhya Xavier
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and
| | - Radovan Vasko
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and Department of Nephrology and Rheumatology, University Medical Center, Goettingen, Germany
| | - Kei Matsumoto
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and
| | - Joseph A Zullo
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and
| | - Robert Chen
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and
| | - Julien Maizel
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and
| | | | - Michael S Goligorsky
- Departments of Medicine, Pharmacology, Physiology, and Renal Research Institute, New York Medical College, Valhalla, New York; and
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Carneiro MFH, Oliveira Souza JM, Grotto D, Batista BL, de Oliveira Souza VC, Barbosa F. A systematic study of the disposition and metabolism of mercury species in mice after exposure to low levels of thimerosal (ethylmercury). ENVIRONMENTAL RESEARCH 2014; 134:218-227. [PMID: 25173055 DOI: 10.1016/j.envres.2014.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 07/15/2014] [Accepted: 07/17/2014] [Indexed: 06/03/2023]
Abstract
Thimerosal (TM) is an ethylmercury (etHg)-containing preservative used in some vaccines despite very limited knowledge on the kinetics and direct interaction/effects in mammals׳ tissues after exposure. Thus, this study aimed to evaluate the kinetics of Hg species in mice in a time course analysis after intramuscular injection of TM, by estimating Hg half-lives in blood and tissues. Mice were exposed to one single intramuscular dose of 20 µg of Hg as TM. Blood, brain, heart, kidney and liver were collected at 0.5 hour (h), 1 h, 8 h, 16 h, 144 h, 720 h and 1980 h after TM exposure (n=4). Hg species in animal tissues were identified and quantified by speciation analysis via liquid chromatography hyphenated with inductively coupled mass spectrometry (LC-ICP-MS). It was found that the transport of etHg from muscle to tissues and its conversion to inorganic Hg (inoHg) occur rapidly. Moreover, the conversion extent is modulated in part by the partitioning between EtHg in plasma and in whole blood, since etHg is rapidly converted in red cells but not in a plasma compartment. Furthermore, the dealkylation mechanism in red cells appears to be mediated by the Fenton reaction (hydroxyl radical formation). Interestingly, after 0.5 h of TM exposure, the highest levels of both etHg and inoHg were found in kidneys (accounting for more than 70% of the total Hg in the animal body), whereas the brain contributed least to the Hg body burden (accounts for <1.0% of total body Hg). Thirty days after TM exposure, most Hg had been excreted while the liver presented the majority of the remaining Hg. Estimated half-lives (in days) were 8.8 for blood, 10.7 for brain, 7.8 for heart, 7.7 for liver and 45.2 for kidney. Taken together, our findings demonstrated that TM (etHg) kinetics more closely approximates Hg(2+) than methylmercury (meHg) while the kidney must be considered a potential target for etHg toxicity.
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Affiliation(s)
- Maria Fernanda Hornos Carneiro
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP, Brazil.
| | - Juliana Maria Oliveira Souza
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP, Brazil.
| | - Denise Grotto
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade de Sorocaba, Rodovia Raposo Tavares km 92.5, CEP 18023-000 Sorocaba, SP, Brazil.
| | - Bruno Lemos Batista
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP, Brazil; Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Bloco B, Avenida dos Estados 5001, CEP 0910-170 Santo André, SP, Brazil.
| | - Vanessa Cristina de Oliveira Souza
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP, Brazil.
| | - Fernando Barbosa
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP, Brazil.
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61
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Elias BC, Mathew S, Srichai MB, Palamuttam R, Bulus N, Mernaugh G, Singh AB, Sanders CR, Harris RC, Pozzi A, Zent R. The integrin β1 subunit regulates paracellular permeability of kidney proximal tubule cells. J Biol Chem 2014; 289:8532-44. [PMID: 24509849 DOI: 10.1074/jbc.m113.526509] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epithelial cells lining the gastrointestinal tract and kidney have different abilities to facilitate paracellular and transcellular transport of water and solutes. In the kidney, the proximal tubule allows both transcellular and paracellular transport, while the collecting duct primarily facilitates transcellular transport. The claudins and E-cadherin are major structural and functional components regulating paracellular transport. In this study we present the novel finding that the transmembrane matrix receptors, integrins, play a role in regulating paracellular transport of renal proximal tubule cells. Deleting the integrin β1 subunit in these cells converts them from a "loose" epithelium, characterized by low expression of E-cadherin and claudin-7 and high expression of claudin-2, to a "tight" epithelium with increased E-cadherin and claudin-7 expression and decreased claudin-2 expression. This effect is mediated by the integrin β1 cytoplasmic tail and does not entail β1 heterodimerization with an α-subunit or its localization to the cell surface. In addition, we demonstrate that deleting the β1 subunit in the proximal tubule of the kidney results in a major urine-concentrating defect. Thus, the integrin β1 tail plays a key role in regulating the composition and function of tight and adherens junctions that define paracellular transport properties of terminally differentiated renal proximal tubule epithelial cells.
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Affiliation(s)
- Bertha C Elias
- From the Division of Nephrology and Hypertension, Department of Medicine
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62
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Zhang MZ, Wang Y, Yao B, Gewin L, Wei S, Capdevila JH, Harris RC. Role of epoxyeicosatrienoic acids (EETs) in mediation of dopamine's effects in the kidney. Am J Physiol Renal Physiol 2013; 305:F1680-6. [PMID: 24154693 DOI: 10.1152/ajprenal.00409.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We have recently demonstrated that intrarenal dopamine plays an important role in preventing the development of systemic hypertension. Similarly, renal cytochrome P-450 (CYP)-epoxygenase-derived arachidonic acid metabolites, epoxyeicosatrienoic acids (EETs), also are antihypertensive through inhibiting sodium reabsorption and vasodilation. The potential interaction between renal dopamine and epoxygenase systems was investigated. Catechol-O-methyl-transferase (COMT)(-/-) mice with increased intrarenal dopamine levels and proximal tubule deletion of aromatic amino acid decarboxylase (ptAADC(-/-)) mice with renal dopamine deficiency were treated with a low-salt diet or high-salt diet for 2 wk. Wild-type or Cyp2c44(-/-) mice were treated with gludopa, which selectively increased renal dopamine levels. In low salt-treated mice, urinary EET levels were related to renal dopamine levels, being highest in COMT(-/-) mice and lowest in ptAADC(-/-) mice. In high salt-treated mice, total EET and individual EET levels in both the kidney and urine were also highest in COMT(-/-) mice and lowest in ptAADC(-/-) mice. Selective increases in renal dopamine in response to gludopa administration led to marked increases in both total and all individual EET levels in the kidney without any changes in blood levels. qRT-PCR and immunoblotting indicated that gludopa increased renal Cyp2c44 mRNA and protein levels. Gludopa induced marked increases in urine volume and urinary sodium excretion in wild-type mice. In contrast, gludopa did not induce significant increases in urine volume or urinary sodium excretion in Cyp2c44(-/-) mice. These studies demonstrate that renal EET levels are maintained by intrarenal dopamine, and Cyp2c44-derived EETs play an important role in intrarenal dopamine-induced natriuresis and diuresis.
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Affiliation(s)
- Ming-Zhi Zhang
- Div. of Nephrology, C3121 MCN, Vanderbilt Univ. School of Medicine and Nashville Veterans Affairs Hospital, Nashville, TN 37232.
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Loeffler I, Wolf G. Transforming growth factor-β and the progression of renal disease. Nephrol Dial Transplant 2013; 29 Suppl 1:i37-i45. [PMID: 24030832 DOI: 10.1093/ndt/gft267] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Transforming growth factor-β (TGF-β) is a profibrotic cytokine found in chronic renal diseases, which initiates and modulates a variety of pathophysiological processes. It is synthesized by many renal cell types and exerts its biological functions through a variety of signalling pathways, including the Smad and MAPK pathways. In renal diseases, TGF-β is upregulated and induces renal cells to produce extracellular matrix proteins leading to glomerulosclerosis as well as tubulointerstitial fibrosis. Different types of renal cells undergo different pathophysiological changes induced by TGF-β, leading to apoptosis, hypertrophy and abnormalities of podocyte foot processes, which ultimately result in renal dysfunction. In this review, we describe the effects of TGF-β on different renal cell types and the means by which TGF-β participates in the pathomechanisms of glomerular and tubulointerstitial diseases.
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Affiliation(s)
- Ivonne Loeffler
- Department of Internal Medicine III, University Hospital Jena, Jena, Germany
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Chung ACK, Lan HY. Molecular Mechanisms of TGF-β Signaling in Renal Fibrosis. CURRENT PATHOBIOLOGY REPORTS 2013. [DOI: 10.1007/s40139-013-0027-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gentle ME, Shi S, Daehn I, Zhang T, Qi H, Yu L, D'Agati VD, Schlondorff DO, Bottinger EP. Epithelial cell TGFβ signaling induces acute tubular injury and interstitial inflammation. J Am Soc Nephrol 2013; 24:787-99. [PMID: 23539761 DOI: 10.1681/asn.2012101024] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
TGFβ signaling plays a central role in the development of acute and chronic kidney diseases. Previous in vivo studies involved systemic alteration of TGFβ signaling, however, limiting conclusions about the direct role of TGFβ in tubular cell injury. Here, we generated a double transgenic mouse that inducibly expresses a ligand-independent constitutively active TGFβ receptor type 1 (TβR1) kinase specifically in tubular epithelial cells, with expression restricted by the Pax8 promoter. In this model, activation of TGFβ signaling in the tubular epithelium alone was sufficient to cause AKI characterized by marked tubular cell apoptosis and necrosis, oxidative stress, dedifferentiation and regenerative cell proliferation, reduced renal function, and interstitial accumulation of inflammatory cells. This tubular injury was associated with mitochondrial-derived generation of reactive oxygen species (ROS), but cell damage and apoptosis were partially independent of mitochondrial-derived ROS. TβR1 signaling-induced tubular injury also associated with significant leukocyte infiltration consisting of F4/80(+) macrophages, CD11c(+) F4/80(+) dendritic cells, CD11c(+) F4/80(-) Ly6C(high) dendritic cells/monocytes, and T cells. Inhibition of mitochondrial-derived ROS significantly reduced accumulation of CD11c(+) F4/80(+) dendritic cells and T cells, suggesting a role for ROS in the activation and recruitment of the adaptive immune response to tubular injury. Taken together, these results suggest that TGFβ signaling in the tubular epithelium alone is sufficient to cause acute tubular injury and inflammation; therefore, TGFβ may be a mechanistic link between acute injury and chronic progression of kidney disease.
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Affiliation(s)
- Madeleine E Gentle
- Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, USA
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