201
|
Relevance of VEGF and nephrin expression in glomerular diseases. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2011:718609. [PMID: 21808734 PMCID: PMC3144718 DOI: 10.1155/2011/718609] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 05/25/2011] [Indexed: 12/23/2022]
Abstract
The glomerular filtration barrier is affected in a large number of acquired and inherited diseases resulting in extensive leakage of plasma albumin and larger proteins, leading to nephrotic syndrome and end-stage renal disease. Unfortunately, the molecular mechanisms governing the development of the nephrotic syndrome remain poorly understood. Here, I give an overview of recent investigations that have focused on characterizing the interrelationships between the slit diaphragm components and podocytes-secreted VEGF, which have a significant role for maintaining the normal podocyte structure and the integrity of the filtering barrier.
Collapse
|
202
|
Johnson S, Waters A. Is complement a culprit in infection-induced forms of haemolytic uraemic syndrome? Immunobiology 2011; 217:235-43. [PMID: 21852019 DOI: 10.1016/j.imbio.2011.07.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Revised: 06/30/2011] [Accepted: 07/18/2011] [Indexed: 12/25/2022]
Abstract
Haemolytic uraemic syndrome (HUS) accounts for the most common cause of childhood acute renal failure. Characterized by the classical triad of a microangiopathic haemolytic anaemia, thrombocytopaenia and acute renal failure, HUS occurs as a result of Shiga-toxin producing microbes in 90% of cases. The remaining 10% of cases represent a heterogeneous subgroup in which inherited and acquired forms of complement dysregulation have been described in up to 60%. Emerging evidence suggests that microbes associated with HUS exhibit interaction with the complement system. With the advent of improved genetic diagnosis, it is likely that certain cases of infection-induced HUS may be attributed to underlying defects in complement components. This review summarises the interplay between complement and infection in the pathogenesis of HUS.
Collapse
Affiliation(s)
- Sally Johnson
- Department of Paediatric Nephrology, Great North Children's Hospital, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle Upon Tyne, UK.
| | | |
Collapse
|
203
|
Piscione TD, Licht C. Genetics of proteinuria: an overview of gene mutations associated with nonsyndromic proteinuric glomerulopathies. Adv Chronic Kidney Dis 2011; 18:273-89. [PMID: 21782134 DOI: 10.1053/j.ackd.2011.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 06/02/2011] [Accepted: 06/16/2011] [Indexed: 02/08/2023]
Abstract
Heritable causes of proteinuria are rare and account for a relatively small proportion of all cases of proteinuria affecting children and adults. Yet, significant contributions to understanding the mechanistic basis for proteinuria have been made through genetic and molecular analyses of a small group of syndromic and nonsyndromic proteinuric disorders which are caused by mutations encoding structural components of the glomerular filtration barrier. Technological advances in genomic analyses and improved accessibility to mutational screening at clinically approved laboratories have facilitated diagnosis of proteinuria in the clinical setting. From a clinical standpoint, it may be argued that a genetic diagnosis mitigates exposure to potentially ineffective and harmful treatments in instances where a clear genotype-phenotype correlation exists between a specific gene mutation and treatment nonresponsiveness. However, cautious interpretation of risk may be necessitated in cases with phenotypic heterogeneity (eg, variability in clinical or histological presentation). This review summarizes gene mutations which are known to be associated with proteinuric glomerulopathies in children and adults.
Collapse
|
204
|
Ma J, Matsusaka T, Yang HC, Zhong J, Takagi N, Fogo AB, Kon V, Ichikawa I. Induction of podocyte-derived VEGF ameliorates podocyte injury and subsequent abnormal glomerular development caused by puromycin aminonucleoside. Pediatr Res 2011; 70:83-9. [PMID: 21451433 PMCID: PMC3113658 DOI: 10.1203/pdr.0b013e31821bdf1c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Our previous studies using puromycin aminonucleoside (PAN) established that podocyte damage leads to glomerular growth arrest during development and glomerulosclerosis later in life. This study examined the potential benefit of maintaining podocyte-derived VEGF in podocyte defense and survival after PAN injury using conditional transgenic podocytes and mice, in which human VEGF-A (hVEGF) transgene expression is controlled by tetracycline responsive element (TRE) promoter and reverse tetracycline transactivator (rtTA) in podocytes. In vitro experiments used primary cultured podocytes harvested from mice carrying podocin-rtTA and TRE-hVEGF transgenes, in which hVEGF can be induced selectively. Induction of VEGF in PAN-exposed podocytes resulted in preservation of intrinsic VEGF, α-actinin-4 and synaptopodin, antiapoptotic marker Bcl-xL/Bax, as well as attenuation in apoptotic marker cleaved/total caspase-3. In vivo, compared with genotype controls, PAN-sensitive neonatal mice with physiologically relevant levels of podocyte-derived VEGF showed significantly larger glomeruli. Furthermore, PAN-induced up-regulation of desmin, down-regulation of synaptopodin and nephrin, and disruption of glomerular morphology were significantly attenuated in VEGF-induced transgenic mice. Our data indicate that podocyte-derived VEGF provides self-preservation functions, which can rescue the cell after injury and preempt subsequent deterioration of the glomerulus in developing mice.
Collapse
Affiliation(s)
- Ji Ma
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
| | | | | | | | | | | | | | | |
Collapse
|
205
|
CORRECTION. J Am Soc Nephrol 2011; 22:1390. [PMID: 37001047 DOI: 10.1681/01.asn.0000926932.40856.61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023] Open
|
206
|
Wei C, Reiser J. Minimal change disease as a modifiable podocyte paracrine disorder. Nephrol Dial Transplant 2011; 26:1776-7. [PMID: 21414975 PMCID: PMC3145403 DOI: 10.1093/ndt/gfr124] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 12/12/2022] Open
Affiliation(s)
- Changli Wei
- Division of Nephrology and Hypertension, Leonard Miller School of Medicine, University of Miami, Miami, FL, USA.
| | | |
Collapse
|
207
|
Jeansson M, Gawlik A, Anderson G, Li C, Kerjaschki D, Henkelman M, Quaggin SE. Angiopoietin-1 is essential in mouse vasculature during development and in response to injury. J Clin Invest 2011; 121:2278-89. [PMID: 21606590 DOI: 10.1172/jci46322] [Citation(s) in RCA: 331] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 04/20/2011] [Indexed: 12/19/2022] Open
Abstract
Angiopoietin-1/Tek signaling is a critical regulator of blood vessel development, with conventional knockout of angiopoietin-1 or Tek in mice being embryonically lethal due to vascular defects. In addition, angiopoietin-1 is thought to be required for the stability of mature vessels. Using a Cre-Lox conditional gene targeting approach, we have studied the role of angiopoietin-1 in embryonic and adult vasculature. We report here that angiopoietin-1 is critical for regulating both the number and diameter of developing vessels but is not required for pericyte recruitment. Cardiac-specific knockout of angiopoietin-1 reproduced the phenotype of the conventional knockout, demonstrating that the early vascular abnormalities arise from flow-dependent defects. Strikingly, deletion in the entire embryo after day E13.5 produced no immediate vascular phenotype. However, when combined with injury or microvascular stress, angiopoietin-1 deficiency resulted in profound organ damage, accelerated angiogenesis, and fibrosis. These findings redefine our understanding of the biological roles of angiopoietin-1: it is dispensable in quiescent vessels but has a powerful ability to modulate the vascular response after injury.
Collapse
Affiliation(s)
- Marie Jeansson
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Canada
| | | | | | | | | | | | | |
Collapse
|
208
|
Sato W, Tanabe K, Kosugi T, Hudkins K, Lanaspa MA, Zhang L, Campbell-Thompson M, Li Q, Long DA, Alpers CE, Nakagawa T. Selective stimulation of VEGFR2 accelerates progressive renal disease. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:155-66. [PMID: 21640973 DOI: 10.1016/j.ajpath.2011.03.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 03/09/2011] [Accepted: 03/29/2011] [Indexed: 01/17/2023]
Abstract
Vascular endothelial growth factor A (VEGF-A) can play both beneficial and deleterious roles in renal diseases, where its specific function might be determined by nitric oxide bioavailability. The complexity of VEGF-A in renal disease could in part be accounted for by the distinct roles of its two receptors; VEGFR1 is involved in the inflammatory responses, whereas VEGFR2 predominantly mediates angiogenesis. Because nondiabetic chronic renal disease is associated with capillary loss, we hypothesized that selective stimulation of VEGFR2 could be beneficial in this setting. However, VEGFR2 activation may be deleterious in the presence of nitric oxide deficiency. We systematically overexpressed a mutant form of VEGF-A binding only VEGFR2 (Flk-sel) using an adeno-associated virus-1 vector in wild-type and eNOS knockout mice and then induced renal injury by uninephrectomy. Flk-sel treatment increased angiogenesis and lowered blood pressure in both mouse types. Flk-sel overexpression caused mesangial injury with increased proliferation associated with elevated expression of PDGF, PDGF-β receptor, and VEGFR2; this effect was greater in eNOS knockout than in wild-type mice. Flk-sel also induced tubulointerstitial injury, with some tubular epithelial cells expressing α-smooth muscle actin, indicating a phenotypic evolution toward myofibroblasts. In conclusion, prestimulation of VEGFR2 can potentiate subsequent renal injury in mice, an effect enhanced in the setting of nitric oxide deficiency.
Collapse
Affiliation(s)
- Waichi Sato
- Division of Nephrology, University of Florida, Gainesville, Florida, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
209
|
George M, Rainey MA, Naramura M, Foster KW, Holzapfel MS, Willoughby LL, Ying G, Goswami RM, Gurumurthy CB, Band V, Satchell SC, Band H. Renal thrombotic microangiopathy in mice with combined deletion of endocytic recycling regulators EHD3 and EHD4. PLoS One 2011; 6:e17838. [PMID: 21408024 PMCID: PMC3052385 DOI: 10.1371/journal.pone.0017838] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Accepted: 02/15/2011] [Indexed: 11/19/2022] Open
Abstract
Eps15 Homology Domain-containing 3 (EHD3), a member of the EHD protein family that regulates endocytic recycling, is the first protein reported to be specifically expressed in the glomerular endothelium in the kidney; therefore we generated Ehd3(-/-) mice and assessed renal development and pathology. Ehd3(-/-) animals showed no overt defects, and exhibited no proteinuria or glomerular pathology. However, as the expression of EHD4, a related family member, was elevated in the glomerular endothelium of Ehd3(-/-) mice and suggested functional compensation, we generated and analyzed Ehd3(-/-); Ehd4(-/-) mice. These mice were smaller, possessed smaller and paler kidneys, were proteinuric and died between 3-24 weeks of age. Detailed analyses of Ehd3(-/-); Ehd4(-/-) kidneys demonstrated thrombotic microangiopathy (TMA)-like glomerular lesions including thickening and duplication of glomerular basement membrane, endothelial swelling and loss of fenestrations. Other changes included segmental podocyte foot process effacement, mesangial interposition, and abnormal podocytic and mesangial marker expression. The glomerular lesions observed were strikingly similar to those seen in human pre-eclampsia and mouse models of reduced VEGF expression. As altered glomerular endothelial VEGFR2 expression and localization and increased apoptosis was observed in the absence of EHD3 and EHD4, we propose that EHD-mediated endocytic traffic of key surface receptors such as VEGFR2 is essential for physiological control of glomerular function. Furthermore, Ehd3(-/-); Ehd4(-/-) mice provide a unique model to elucidate mechanisms of glomerular endothelial injury which is observed in a wide variety of human renal and extra-renal diseases.
Collapse
Affiliation(s)
- Manju George
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail: (MG); (MN); (HB)
| | - Mark A. Rainey
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Mayumi Naramura
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail: (MG); (MN); (HB)
| | - Kirk W. Foster
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Melissa S. Holzapfel
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Laura L. Willoughby
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - GuoGuang Ying
- Oncology Central Laboratory, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Rasna M. Goswami
- Abbott Laboratories, Abbott Park, Illinois, United States of America
| | - Channabasavaiah B. Gurumurthy
- Department of Genetics, Cell Biology and Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Vimla Band
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Genetics, Cell Biology and Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | | | - Hamid Band
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Genetics, Cell Biology and Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Departments of Biochemistry and Molecular Biology, and Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail: (MG); (MN); (HB)
| |
Collapse
|
210
|
Jeong IK, King GL. New perspectives on diabetic vascular complications: the loss of endogenous protective factors induced by hyperglycemia. Diabetes Metab J 2011; 35:8-11. [PMID: 21537407 PMCID: PMC3080576 DOI: 10.4093/dmj.2011.35.1.8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diabetic vascular complications are among the leading causes of morbidity and mortality in diabetic patients. In the past, many studies have focused on the mechanisms of hyperglycemia-induced chronic vascular complications via the formation of toxic metabolites such as oxidative stress, advanced glycosylated end products, persistent activation of protein kinase C, and increased sorbitol concentrations. However, vascular complications result from imbalances caused by increases in systemic toxic metabolites, such as those that occur under conditions of hyperglycemia and dyslipidemia, and by reductions in endogenous protective factors such as insulin, vascular endothelial growth factor, and platelet derived growth factor. This review outlines some of the evidence supporting the importance of enhancing endogenous regenerative factors.
Collapse
Affiliation(s)
- In-Kyung Jeong
- Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea
| | - George L. King
- Section on Vascular Cell Biology, Joslin Diabetes Center, Harvard University, Boston, MA, USA
| |
Collapse
|
211
|
Renal involvement in preeclampsia: similarities to VEGF ablation therapy. J Pregnancy 2010; 2011:176973. [PMID: 21494322 PMCID: PMC3066648 DOI: 10.1155/2011/176973] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2010] [Accepted: 11/01/2010] [Indexed: 11/17/2022] Open
Abstract
Glomerular VEGF expression is critical for the maintenance and function of an intact filtration barrier. Alterations in glomerular VEGF bioavailability result in endothelial as well as in podocyte damage. Renal involvement in preeclampsia includes proteinuria, podocyturia, elevated blood pressure, edema, glomerular capillary endotheliosis, and thrombotic microangiopathy. At least the renal signs, symptoms, and other evidence can sufficiently be explained by reduced VEGF levels. The aim of this paper was to summarize our pathophysiological understanding of the renal involvement of preeclampsia and point out similarities to the renal side effects of VEGF-ablation therapy.
Collapse
|
212
|
Abstract
Shiga toxin-producing Escherichia coli is a contaminant of food and water that in humans causes a diarrheal prodrome followed by more severe disease of the kidneys and an array of symptoms of the central nervous system. The systemic disease is a complex referred to as diarrhea-associated hemolytic uremic syndrome (D+HUS). D+HUS is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. This review focuses on the renal aspects of D+HUS. Current knowledge of this renal disease is derived from a combination of human samples, animal models of D+HUS, and interaction of Shiga toxin with isolated renal cell types. Shiga toxin is a multi-subunit protein complex that binds to a glycosphingolipid receptor, Gb3, on select eukaryotic cell types. Location of Gb3 in the kidney is predictive of the sites of action of Shiga toxin. However, the toxin is cytotoxic to some, but not all cell types that express Gb3. It also can cause apoptosis or generate an inflammatory response in some cells. Together, this myriad of results is responsible for D+HUS disease.
Collapse
Affiliation(s)
- Tom G Obrig
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, 685 W. Baltimore St., HSF I Suite 380, Baltimore, MD 21201, USA; ; Tel.: +1-410-706-6917
| |
Collapse
|
213
|
|
214
|
|