1
|
Finch NC, Neal CR, Welsh GI, Foster RR, Satchell SC. The unique structural and functional characteristics of glomerular endothelial cell fenestrations and their potential as a therapeutic target in kidney disease. Am J Physiol Renal Physiol 2023; 325:F465-F478. [PMID: 37471420 PMCID: PMC10639027 DOI: 10.1152/ajprenal.00036.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023] Open
Abstract
Glomerular endothelial cell (GEnC) fenestrations are a critical component of the glomerular filtration barrier. Their unique nondiaphragmed structure is key to their function in glomerular hydraulic permeability, and their aberration in disease can contribute to loss of glomerular filtration function. This review provides a comprehensive update of current understanding of the regulation and biogenesis of fenestrae. We consider diseases in which GEnC fenestration loss is recognized or may play a role and discuss methods with potential to facilitate the study of these critical structures. Literature is drawn from GEnCs as well as other fenestrated cell types such as liver sinusoidal endothelial cells that most closely parallel GEnCs.
Collapse
Affiliation(s)
- Natalie C Finch
- Bristol Renal, University of Bristol, United Kingdom
- Langford Vets, University of Bristol, United Kingdom
| | - Chris R Neal
- Bristol Renal, University of Bristol, United Kingdom
| | - Gavin I Welsh
- Bristol Renal, University of Bristol, United Kingdom
| | | | | |
Collapse
|
2
|
Staruschenko A, Ma R, Palygin O, Dryer SE. Ion channels and channelopathies in glomeruli. Physiol Rev 2023; 103:787-854. [PMID: 36007181 PMCID: PMC9662803 DOI: 10.1152/physrev.00013.2022] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 11/22/2022] Open
Abstract
An essential step in renal function entails the formation of an ultrafiltrate that is delivered to the renal tubules for subsequent processing. This process, known as glomerular filtration, is controlled by intrinsic regulatory systems and by paracrine, neuronal, and endocrine signals that converge onto glomerular cells. In addition, the characteristics of glomerular fluid flow, such as the glomerular filtration rate and the glomerular filtration fraction, play an important role in determining blood flow to the rest of the kidney. Consequently, disease processes that initially affect glomeruli are the most likely to lead to end-stage kidney failure. The cells that comprise the glomerular filter, especially podocytes and mesangial cells, express many different types of ion channels that regulate intrinsic aspects of cell function and cellular responses to the local environment, such as changes in glomerular capillary pressure. Dysregulation of glomerular ion channels, such as changes in TRPC6, can lead to devastating glomerular diseases, and a number of channels, including TRPC6, TRPC5, and various ionotropic receptors, are promising targets for drug development. This review discusses glomerular structure and glomerular disease processes. It also describes the types of plasma membrane ion channels that have been identified in glomerular cells, the physiological and pathophysiological contexts in which they operate, and the pathways by which they are regulated and dysregulated. The contributions of these channels to glomerular disease processes, such as focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy, as well as the development of drugs that target these channels are also discussed.
Collapse
Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, Texas
| |
Collapse
|
3
|
Finch NC, Fawaz SS, Neal CR, Butler MJ, Lee VK, Salmon AJ, Lay AC, Stevens M, Dayalan L, Band H, Mellor HH, Harper SJ, Shima DT, Welsh GI, Foster RR, Satchell SC. Reduced Glomerular Filtration in Diabetes Is Attributable to Loss of Density and Increased Resistance of Glomerular Endothelial Cell Fenestrations. J Am Soc Nephrol 2022; 33:1120-1136. [PMID: 35292439 PMCID: PMC9161794 DOI: 10.1681/asn.2021030294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 03/01/2022] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Glomerular endothelial cell (GEnC) fenestrations are recognized as an essential component of the glomerular filtration barrier, yet little is known about how they are regulated and their role in disease. METHODS We comprehensively characterized GEnC fenestral and functional renal filtration changes including measurement of glomerular Kf and GFR in diabetic mice (BTBR ob-/ob- ). We also examined and compared human samples. We evaluated Eps homology domain protein-3 (EHD3) and its association with GEnC fenestrations in diabetes in disease samples and further explored its role as a potential regulator of fenestrations in an in vitro model of fenestration formation using b.End5 cells. RESULTS Loss of GEnC fenestration density was associated with decreased filtration function in diabetic nephropathy. We identified increased diaphragmed fenestrations in diabetes, which are posited to increase resistance to filtration and further contribute to decreased GFR. We identified decreased glomerular EHD3 expression in diabetes, which was significantly correlated with decreased fenestration density. Reduced fenestrations in EHD3 knockdown b.End5 cells in vitro further suggested a mechanistic role for EHD3 in fenestration formation. CONCLUSIONS This study demonstrates the critical role of GEnC fenestrations in renal filtration function and suggests EHD3 may be a key regulator, loss of which may contribute to declining glomerular filtration function through aberrant GEnC fenestration regulation. This points to EHD3 as a novel therapeutic target to restore filtration function in disease.
Collapse
Affiliation(s)
- Natalie C. Finch
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Sarah S. Fawaz
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Chris R. Neal
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Matthew J. Butler
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Vivian K. Lee
- Translational Vision Research, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Andrew J. Salmon
- Renal Service, Waitemata District Health Board, Auckland, New Zealand
| | - Abigail C. Lay
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Megan Stevens
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Lusyan Dayalan
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Hamid Band
- Eppley Institute for Research in Cancer, and Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska
| | - Harry H. Mellor
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Steven J. Harper
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - David T. Shima
- Translational Vision Research, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Gavin I. Welsh
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Rebecca R. Foster
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Simon C. Satchell
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
4
|
Stevens M, Neal CR, Craciun EC, Dronca M, Harper SJ, Oltean S. The natural drug DIAVIT is protective in a type II mouse model of diabetic nephropathy. PLoS One 2019; 14:e0212910. [PMID: 30865689 PMCID: PMC6415805 DOI: 10.1371/journal.pone.0212910] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 02/10/2019] [Indexed: 02/06/2023] Open
Abstract
There is evidence to suggest that abnormal angiogenesis, inflammation, and fibrosis drive diabetic nephropathy (DN). However, there is no specific treatment to counteract these processes. We aimed to determine whether DIAVIT, a natural Vaccinium myrtillus (blueberry) and Hippophae Rhamnoides (sea buckthorn) extract, is protective in a model of type II DN. Diabetic db/db mice were administered DIAVIT in their drinking water for 14 weeks. We assessed the functional, structural, and ultra-structural phenotype of three experimental groups (lean+vehicle, db/db+vehicle, db/db+DIAVIT). We also investigated the angiogenic and fibrotic pathways involved in the mechanism of action of DIAVIT. Diabetic db/db mice developed hyperglycaemia, albuminuria, and an increased glomerular water permeability; the latter two were prevented by DIAVIT. db/db mice developed fibrotic glomeruli, endothelial insult, and glomerular ultra-structural changes, which were not present in DIAVIT-treated mice. Vascular endothelial growth factor A (VEGF-A) splicing was altered in the db/db kidney cortex, increasing the pro-angiogenic VEGF-A165 relative to the anti-angiogenic VEGF-A165b. This was partially prevented with DIAVIT treatment. Delphinidin, an anthocyanin abundant in DIAVIT, increased the VEGF-A165b expression relative to total VEGF-A165 in cultured podocytes through phosphorylation of the splice factor SRSF6. DIAVIT, in particular delphinidin, alters VEGF-A splicing in type II DN, rescuing the DN phenotype. This study highlights the therapeutic potential of natural drugs in DN through the manipulation of gene splicing and expression.
Collapse
Affiliation(s)
- Megan Stevens
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail: (MS); (SO)
| | - Christopher R. Neal
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Elena C. Craciun
- Department of Pharmaceutical Biochemistry and Clinical Laboratory, School of Pharmacy, University of Medicine and Pharmacy “Iuliu Hatieganu” Cluj-Napoca, Romania
| | - Maria Dronca
- Department of Medical Biochemistry, School of Medicine, University of Medicine and Pharmacy “Iuliu Hatieganu” Cluj-Napoca, Romania
| | - Steven J. Harper
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail: (MS); (SO)
| |
Collapse
|
5
|
Kikuchi R, Stevens M, Harada K, Oltean S, Murohara T. Anti-angiogenic isoform of vascular endothelial growth factor-A in cardiovascular and renal disease. Adv Clin Chem 2019; 88:1-33. [PMID: 30612603 DOI: 10.1016/bs.acc.2018.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Accumulating evidence suggests that pathologic interactions between the heart and the kidney can contribute to the progressive dysfunction of both organs. Recently, there has been an increase in the prevalence of cardiovascular disease (CVD) and chronic kidney disease (CKD) due to increasing obesity rates. It has been reported that obesity causes various heart and renal disorders and appears to accelerate their progression. Vascular endothelial growth factor-A (VEGF-A) is a major regulator of angiogenesis and vessel permeability, and is associated with CVD and CKD. It is now recognized that alternative VEGF-A gene splicing generates VEGF-A isoforms that differ in their biological actions. Proximal splicing that includes an exon 8a sequence results in pro-angiogenic VEGF-A165a, whereas distal splicing inclusive of exon 8b yields the anti-angiogenic isoform of VEGF-A (VEGF-A165b). This review highlights several recent preclinical and clinical studies on the role of VEGF-A165b in CVD and CKD as a novel function of VEGF-A. This review also discusses potential therapeutic approaches of the use of VEGF-A in clinical settings as a potential circulating biomarker for CVD and CKD.
Collapse
Affiliation(s)
- Ryosuke Kikuchi
- Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
| | - Megan Stevens
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Kazuhiro Harada
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|
6
|
Błochowiak K, Sokalski J, Golusińska E, Trzybulska D, Witmanowski H, Bodnar M, Marszałek A. Salivary levels and immunohistochemical expression of selected angiogenic factors in benign and malignant parotid gland tumours. Clin Oral Investig 2018; 23:995-1006. [DOI: 10.1007/s00784-018-2524-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 06/11/2018] [Indexed: 01/06/2023]
|
7
|
Bates DO, Beazley-Long N, Benest AV, Ye X, Ved N, Hulse RP, Barratt S, Machado MJ, Donaldson LF, Harper SJ, Peiris-Pages M, Tortonese DJ, Oltean S, Foster RR. Physiological Role of Vascular Endothelial Growth Factors as Homeostatic Regulators. Compr Physiol 2018; 8:955-979. [PMID: 29978898 DOI: 10.1002/cphy.c170015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The vascular endothelial growth factor (VEGF) family of proteins are key regulators of physiological systems. Originally linked with endothelial function, they have since become understood to be principal regulators of multiple tissues, both through their actions on vascular cells, but also through direct actions on other tissue types, including epithelial cells, neurons, and the immune system. The complexity of the five members of the gene family in terms of their different splice isoforms, differential translation, and specific localizations have enabled tissues to use these potent signaling molecules to control how they function to maintain their environment. This homeostatic function of VEGFs has been less intensely studied than their involvement in disease processes, development, and reproduction, but they still play a substantial and significant role in healthy control of blood volume and pressure, interstitial volume and drainage, renal and lung function, immunity, and signal processing in the peripheral and central nervous system. The widespread expression of VEGFs in healthy adult tissues, and the disturbances seen when VEGF signaling is inhibited support this view of the proteins as endogenous regulators of normal physiological function. This review summarizes the evidence and recent breakthroughs in understanding of the physiology that is regulated by VEGF, with emphasis on the role they play in maintaining homeostasis. © 2017 American Physiological Society. Compr Physiol 8:955-979, 2018.
Collapse
Affiliation(s)
- David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | | | - Andrew V Benest
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nikita Ved
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Richard P Hulse
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Shaney Barratt
- Academic Respiratory Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Maria J Machado
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Lucy F Donaldson
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Steven J Harper
- School of Physiology, Pharmacology & Neuroscience, Medical School, University of Bristol, Bristol, United Kingdom
| | - Maria Peiris-Pages
- Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
| | - Domingo J Tortonese
- Centre for Comparative and Clinical Anatomy, University of Bristol, Bristol, United Kingdom
| | - Sebastian Oltean
- Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Rebecca R Foster
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
8
|
Modulation of VEGF-A Alternative Splicing as a Novel Treatment in Chronic Kidney Disease. Genes (Basel) 2018; 9:genes9020098. [PMID: 29462869 PMCID: PMC5852594 DOI: 10.3390/genes9020098] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 01/05/2023] Open
Abstract
Vascular endothelial growth factor A (VEGF-A) is a prominent pro-angiogenic and pro-permeability factor in the kidney. Alternative splicing of the terminal exon of VEGF-A through the use of an alternative 3' splice site gives rise to a functionally different family of isoforms, termed VEGF-Axxxb, known to have anti-angiogenic and anti-permeability properties. Dysregulation of the VEGF-Axxx/VEGF-Axxxb isoform balance has recently been reported in several kidney pathologies, including diabetic nephropathy (DN) and Denys-Drash syndrome. Using mouse models of kidney disease where the VEGF-A isoform balance is disrupted, several reports have shown that VEGF-A165b treatment/over-expression in the kidney is therapeutically beneficial. Furthermore, inhibition of certain splice factor kinases involved in the regulation of VEGF-A terminal exon splicing has provided some mechanistic insight into how VEGF-A splicing could be regulated in the kidney. This review highlights the importance of further investigation into the novel area of VEGF-A splicing in chronic kidney disease pathogenesis and how future studies may allow for the development of splicing-modifying therapeutic drugs.
Collapse
|
9
|
Stevens M, Neal CR, Salmon AHJ, Bates DO, Harper SJ, Oltean S. Vascular Endothelial Growth Factor-A165b Restores Normal Glomerular Water Permeability in a Diphtheria-Toxin Mouse Model of Glomerular Injury. Nephron Clin Pract 2018; 139:51-62. [PMID: 29393270 DOI: 10.1159/000485664] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 11/24/2017] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND/AIMS Genetic cell ablation using the human diphtheria toxin receptor (hDTR) is a new strategy used for analysing cellular function. Diphtheria toxin (DT) is a cytotoxic protein that leaves mouse cells relatively unaffected, but upon binding to hDTR it ultimately leads to cell death. We used a podocyte-specific hDTR expressing (Pod-DTR) mouse to assess the anti-permeability and cyto-protective effects of the splice isoform vascular endothelial growth factor (VEGF-A165b). METHODS The Pod-DTR mouse was crossed with a mouse that over-expressed VEGF-A165b specifically in the podocytes (Neph-VEGF-A165b). Wild type (WT), Pod-DTR, Neph-VEGF-A165b and Pod-DTR X Neph-VEGF-A165b mice were treated with several doses of DT (1, 5, 100, and 1,000 ng/g bodyweight). Urine was collected and the glomerular water permeability (LpA/Vi) was measured ex vivo after 14 days. Structural analysis and podocyte marker expression were also assessed. RESULTS Pod-DTR mice developed an increased glomerular LpA/Vi 14 days after administration of DT (all doses), which was prevented when the mice over-expressed VEGF-A165b. No major structural abnormalities, podocyte ablation or albuminuria was observed in Pod-DTR mice, indicating this to be a mild model of podocyte disease. However, a change in expression and localisation of nephrin within the podocytes was observed, indicating disruption of the slit diaphragm in the Pod-DTR mice. This was prevented in the Pod-DTR X Neph-VEGF-A165b mice. CONCLUSION Although only a mild model of podocyte injury, over-expression of the anti-permeability VEGF-A165b isoform in the podocytes of Pod-DTR mice had a protective effect. Therefore, this study further highlights the therapeutic potential of VEGF-A165b in glomerular disease.
Collapse
Affiliation(s)
- Megan Stevens
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom.,School of Physiology, Pharmacology and Neurosciences, Bristol, United Kingdom.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Christopher R Neal
- School of Physiology, Pharmacology and Neurosciences, Bristol, United Kingdom.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Andrew H J Salmon
- School of Physiology, Pharmacology and Neurosciences, Bristol, United Kingdom.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - David O Bates
- Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Steven J Harper
- School of Physiology, Pharmacology and Neurosciences, Bristol, United Kingdom.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom.,School of Physiology, Pharmacology and Neurosciences, Bristol, United Kingdom.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
10
|
Antiangiogenic Therapy for Diabetic Nephropathy. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5724069. [PMID: 28835895 PMCID: PMC5556994 DOI: 10.1155/2017/5724069] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/16/2017] [Accepted: 06/13/2017] [Indexed: 12/28/2022]
Abstract
Angiogenesis has been shown to be a potential therapeutic target for early stages of diabetic nephropathy in a number of animal experiments. Vascular endothelial growth factor (VEGF) is the main mediator for abnormal angiogenesis in diabetic glomeruli. Although beneficial effects of anti-VEGF antibodies have previously been demonstrated in diabetic animal experiments, recent basic and clinical evidence has revealed that the blockade of VEGF signaling resulted in proteinuria and renal thrombotic microangiopathy, suggesting the importance of maintaining normal levels of VEGF in the kidneys. Therefore, antiangiogenic therapy for diabetic nephropathy should eliminate excessive glomerular angiogenic response without accelerating endothelial injury. Some endogenous antiangiogenic factors such as endostatin and tumstatin inhibit overactivation of endothelial cells but do not specifically block VEGF signaling. In addition, the novel endothelium-derived antiangiogenic factor vasohibin-1 enhances stress tolerance and survival of the endothelial cells, while inhibiting excess angiogenesis. These factors have been demonstrated to suppress albuminuria and glomerular alterations in a diabetic mouse model. Thus, antiangiogenic therapy with promising candidates will possibly improve renal prognosis in patients with early stages of diabetic nephropathy.
Collapse
|
11
|
Stevens M, Neal CR, Salmon AHJ, Bates DO, Harper SJ, Oltean S. VEGF-A 165 b protects against proteinuria in a mouse model with progressive depletion of all endogenous VEGF-A splice isoforms from the kidney. J Physiol 2017; 595:6281-6298. [PMID: 28574576 PMCID: PMC5621502 DOI: 10.1113/jp274481] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/17/2017] [Indexed: 01/25/2023] Open
Abstract
Key points Progressive depletion of all vascular endothelial growth factor A (VEGF‐A) splice isoforms from the kidney results in proteinuria and increased glomerular water permeability, which are both rescued by over‐expression of VEGF‐A165b only. VEGF‐A165b rescues the increase in glomerular basement membrane and podocyte slit width, as well as the decrease in sub‐podocyte space coverage, produced by VEGF‐A depletion. VEGF‐A165b restores the expression of platelet endothelial cell adhesion molecule in glomerular endothelial cells and glomerular capillary circumference. VEGF‐A165b has opposite effects to VEGF‐A165 on the expression of genes involved in endothelial cell migration and proliferation.
Abstract Chronic kidney disease is strongly associated with a decrease in the expression of vascular endothelial growth factor A (VEGF‐A). However, little is known about the contribution of VEGF‐A splice isoforms to kidney physiology and pathology. Previous studies suggest that the splice isoform VEGF‐A165b (resulting from alternative usage of a 3′ splice site in the terminal exon) is protective for kidney function. In the present study, we show, in a quad‐transgenic model, that over‐expression of VEGF‐A165b alone is sufficient to rescue the increase in proteinuria, as well as glomerular water permeability, in the context of progressive depletion of all VEGF‐A isoforms from the podocytes. Ultrastructural studies show that the glomerular basement membrane is thickened, podocyte slit width is increased and sub‐podocyte space coverage is reduced when VEGF‐A is depleted, all of which are rescued in VEGF‐A165b over‐expressors. VEGF‐A165b restores the expression of platelet endothelial cell adhesion molecule‐1 in glomerular endothelial cells and glomerular capillary circumference. Mechanistically, it increases VEGF receptor 2 expression both in vivo and in vitro and down‐regulates genes involved in migration and proliferation of endothelial cells, otherwise up‐regulated by the canonical isoform VEGF‐A165. The results of the present study indicate that manipulation of VEGF‐A splice isoforms could be a novel therapeutic avenue in chronic glomerular disease. Progressive depletion of all vascular endothelial growth factor A (VEGF‐A) splice isoforms from the kidney results in proteinuria and increased glomerular water permeability, which are both rescued by over‐expression of VEGF‐A165b only. VEGF‐A165b rescues the increase in glomerular basement membrane and podocyte slit width, as well as the decrease in sub‐podocyte space coverage, produced by VEGF‐A depletion. VEGF‐A165b restores the expression of platelet endothelial cell adhesion molecule in glomerular endothelial cells and glomerular capillary circumference. VEGF‐A165b has opposite effects to VEGF‐A165 on the expression of genes involved in endothelial cell migration and proliferation.
Collapse
Affiliation(s)
- Megan Stevens
- School of Physiology, Pharmacology and Neurosciences, University of Bristol, UK.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK.,Present address: Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Christopher R Neal
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Andrew H J Salmon
- School of Physiology, Pharmacology and Neurosciences, University of Bristol, UK.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, UK
| | - Steven J Harper
- School of Physiology, Pharmacology and Neurosciences, University of Bristol, UK.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Sebastian Oltean
- School of Physiology, Pharmacology and Neurosciences, University of Bristol, UK.,Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, UK.,Present address: Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| |
Collapse
|
12
|
Reina-Torres E, Wen JC, Liu KC, Li G, Sherwood JM, Chang JYH, Challa P, Flügel-Koch CM, Stamer WD, Allingham RR, Overby DR. VEGF as a Paracrine Regulator of Conventional Outflow Facility. Invest Ophthalmol Vis Sci 2017; 58:1899-1908. [PMID: 28358962 PMCID: PMC5374885 DOI: 10.1167/iovs.16-20779] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose Vascular endothelial growth factor (VEGF) regulates microvascular endothelial permeability, and the permeability of Schlemm's canal (SC) endothelium influences conventional aqueous humor outflow. We hypothesize that VEGF signaling regulates outflow facility. Methods We measured outflow facility (C) in enucleated mouse eyes perfused with VEGF-A164a, VEGF-A165b, VEGF-D, or inhibitors to VEGF receptor 2 (VEGFR-2). We monitored VEGF-A secretion from human trabecular meshwork (TM) cells by ELISA after 24 hours of static culture or cyclic stretch. We used immunofluorescence microscopy to localize VEGF-A protein within the TM of mice. Results VEGF-A164a increased C in enucleated mouse eyes. Cyclic stretch increased VEGF-A secretion by human TM cells, which corresponded to VEGF-A localization in the TM of mice. Blockade of VEGFR-2 decreased C, using either of the inhibitors SU5416 or Ki8751 or the inactive splice variant VEGF-A165b. VEGF-D increased C, which could be blocked by Ki8751. Conclusions VEGF is a paracrine regulator of conventional outflow facility that is secreted by TM cells in response to mechanical stress. VEGF affects facility via VEGFR-2 likely at the level of SC endothelium. Disruption of VEGF signaling in the TM may explain why anti-VEGF therapy is associated with decreased outflow facility and sustained ocular hypertension.
Collapse
Affiliation(s)
- Ester Reina-Torres
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Joanne C Wen
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Katy C Liu
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Guorong Li
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Joseph M Sherwood
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Jason Y H Chang
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Pratap Challa
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Cassandra M Flügel-Koch
- Department of Anatomy II, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - R Rand Allingham
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Darryl R Overby
- Department of Bioengineering, Imperial College London, London, United Kingdom
| |
Collapse
|
13
|
Majumder S, Advani A. VEGF and the diabetic kidney: More than too much of a good thing. J Diabetes Complications 2017; 31:273-279. [PMID: 27836681 DOI: 10.1016/j.jdiacomp.2016.10.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 10/18/2016] [Indexed: 02/06/2023]
Abstract
Over a decade and a half has passed since the publication of early reports hinting at a pathogenetic role for vascular endothelial growth factor ("VEGF") in the development of diabetic kidney disease. In diabetic rats, renal mRNA levels of the VEGF-A isoform were upregulated and administration of a VEGF-A neutralizing antibody attenuated albuminuria: VEGF was "bad" in diabetic nephropathy. Since that time, our understanding of the complexity of the renal VEGF system has advanced. Unlike its experimental counterpart, human diabetic nephropathy is associated with diminished VEGF-A levels and experience in the oncological setting has taught us that VEGF blocking therapy can cause adverse renal effects in patients. Correspondingly, investigational studies in cultured cells and rodent models have demonstrated that the biological effects of the VEGF system are dependent not only on the amount of VEGF, but also the type of VEGF, its sites of action and the prevailing milieu. Here we reflect back on the discoveries that have been made since those initial reports that shone the spotlight on the importance of the VEGF system in the diabetic kidney and we consider that the role of VEGF in diabetic nephropathy extends well beyond being "too much of a good thing".
Collapse
Affiliation(s)
- Syamantak Majumder
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada.
| |
Collapse
|
14
|
Abstract
The glomerulus is a highly specialized microvascular bed that filters blood to form primary urinary filtrate. It contains four cell types: fenestrated endothelial cells, specialized vascular support cells termed podocytes, perivascular mesangial cells, and parietal epithelial cells. Glomerular cell-cell communication is critical for the development and maintenance of the glomerular filtration barrier. VEGF, ANGPT, EGF, SEMA3A, TGF-β, and CXCL12 signal in paracrine fashions between the podocytes, endothelium, and mesangium associated with the glomerular capillary bed to maintain filtration barrier function. In this review, we summarize the current understanding of these signaling pathways in the development and maintenance of the glomerulus and the progression of disease.
Collapse
Affiliation(s)
- Christina S Bartlett
- Feinberg Cardiovascular Research Institute and Division of Nephrology and Hypertension, Northwestern University, Chicago, Illinois 60611; ,
| | - Marie Jeansson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 751 85, Sweden;
| | - Susan E Quaggin
- Feinberg Cardiovascular Research Institute and Division of Nephrology and Hypertension, Northwestern University, Chicago, Illinois 60611; ,
| |
Collapse
|
15
|
Loffredo S, Bova M, Suffritti C, Borriello F, Zanichelli A, Petraroli A, Varricchi G, Triggiani M, Cicardi M, Marone G. Elevated plasma levels of vascular permeability factors in C1 inhibitor-deficient hereditary angioedema. Allergy 2016; 71:989-96. [PMID: 26873113 DOI: 10.1111/all.12862] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Hereditary angioedema with C1 inhibitor deficiency (C1-INH-HAE) is a rare inherited genetic disease characterized by recurrent swelling episodes of the skin, gastrointestinal tract, and upper airways. Angioedema attacks result from increased vascular permeability due to the release of bradykinin from high molecular weight kininogen. Currently, there are no biomarkers predicting the frequency of angioedema attacks. Vascular permeability is modulated by several factors, including vascular endothelial growth factors (VEGFs) and angiopoietins (Angs). As increased circulating levels of VEGFs and Angs have been observed in diseases associated with higher vascular permeability (e.g., systemic capillary leak syndrome and sepsis), we sought to analyze plasma concentrations of VEGFs and Angs in patients with C1-INH-HAE. METHODS Sixty-eight healthy controls and 128 patients with C1-INH-HAE were studied. Concentrations of angiogenic (VEGF-A, Ang1, Ang2), anti-angiogenic (VEGF-A165b ) and lymphangiogenic (VEGF-C) factors were evaluated by ELISA. C1-INH functional activity was assessed by EIA. RESULTS Plasma concentrations of VEGF-A, VEGF-C, Ang1, and Ang2 were higher in patients with C1-INH-HAE in remission than in healthy controls. Concentration of VEGF-A was further increased in patients with lower C1-INH functional activity. Patients with C1-INH-HAE experiencing more than 12 angioedema attacks per year were characterized by higher plasma levels of VEGF-A, VEGF-C, and Ang2 compared with the other patients. CONCLUSIONS We hypothesize that VEGFs and Angs induce a state of 'vascular preconditioning' that may predispose to angioedema attacks. In addition, the identification of increased plasma levels of VEGFs and Angs in patients with C1-INH-HAE may prompt the investigation of VEGFs and Angs as biomarkers of C1-INH-HAE severity.
Collapse
Affiliation(s)
- S. Loffredo
- Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI); University of Naples Federico II; Naples Italy
| | - M. Bova
- Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI); University of Naples Federico II; Naples Italy
| | - C. Suffritti
- Department of Biomedical and Clinical Sciences Luigi Sacco; Luigi Sacco Hospital Milan; University of Milan; Milan Italy
| | - F. Borriello
- Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI); University of Naples Federico II; Naples Italy
| | - A. Zanichelli
- Department of Biomedical and Clinical Sciences Luigi Sacco; Luigi Sacco Hospital Milan; University of Milan; Milan Italy
| | - A. Petraroli
- Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI); University of Naples Federico II; Naples Italy
| | - G. Varricchi
- Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI); University of Naples Federico II; Naples Italy
| | - M. Triggiani
- Division of Allergy and Clinical Immunology; University of Salerno; Salerno Italy
| | - M. Cicardi
- Department of Biomedical and Clinical Sciences Luigi Sacco; Luigi Sacco Hospital Milan; University of Milan; Milan Italy
| | - G. Marone
- Department of Translational Medical Sciences and Center for Basic and Clinical Immunology Research (CISI); University of Naples Federico II; Naples Italy
- CNR Institute of Experimental Endocrinology and Oncology ‘G. Salvatore’; Naples Italy
| |
Collapse
|
16
|
Abstract
Kidney glomeruli ultrafilter blood to generate urine and they are dysfunctional in a variety of kidney diseases. There are two key vascular growth factor families implicated in glomerular biology and function, namely the vascular endothelial growth factors (VEGFs) and the angiopoietins (Angpt). We present examples showing not only how these molecules help generate and maintain healthy glomeruli but also how they drive disease when their expression is dysregulated. Finally, we review how manipulating VEGF and Angpt signalling may be used to treat glomerular disease.
Collapse
|
17
|
Oltean S, Qiu Y, Ferguson JK, Stevens M, Neal C, Russell A, Kaura A, Arkill KP, Harris K, Symonds C, Lacey K, Wijeyaratne L, Gammons M, Wylie E, Hulse RP, Alsop C, Cope G, Damodaran G, Betteridge KB, Ramnath R, Satchell SC, Foster RR, Ballmer-Hofer K, Donaldson LF, Barratt J, Baelde HJ, Harper SJ, Bates DO, Salmon AHJ. Vascular Endothelial Growth Factor-A165b Is Protective and Restores Endothelial Glycocalyx in Diabetic Nephropathy. J Am Soc Nephrol 2014; 26:1889-904. [PMID: 25542969 DOI: 10.1681/asn.2014040350] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 10/15/2014] [Indexed: 01/11/2023] Open
Abstract
Diabetic nephropathy is the leading cause of ESRD in high-income countries and a growing problem across the world. Vascular endothelial growth factor-A (VEGF-A) is thought to be a critical mediator of vascular dysfunction in diabetic nephropathy, yet VEGF-A knockout and overexpression of angiogenic VEGF-A isoforms each worsen diabetic nephropathy. We examined the vasculoprotective effects of the VEGF-A isoform VEGF-A165b in diabetic nephropathy. Renal expression of VEGF-A165b mRNA was upregulated in diabetic individuals with well preserved kidney function, but not in those with progressive disease. Reproducing this VEGF-A165b upregulation in mouse podocytes in vivo prevented functional and histologic abnormalities in diabetic nephropathy. Biweekly systemic injections of recombinant human VEGF-A165b reduced features of diabetic nephropathy when initiated during early or advanced nephropathy in a model of type 1 diabetes and when initiated during early nephropathy in a model of type 2 diabetes. VEGF-A165b normalized glomerular permeability through phosphorylation of VEGF receptor 2 in glomerular endothelial cells, and reversed diabetes-induced damage to the glomerular endothelial glycocalyx. VEGF-A165b also improved the permeability function of isolated diabetic human glomeruli. These results show that VEGF-A165b acts via the endothelium to protect blood vessels and ameliorate diabetic nephropathy.
Collapse
Affiliation(s)
| | - Yan Qiu
- School of Physiology and Pharmacology and
| | | | | | - Chris Neal
- School of Physiology and Pharmacology and
| | | | - Amit Kaura
- School of Physiology and Pharmacology and
| | | | | | | | | | | | | | - Emma Wylie
- School of Physiology and Pharmacology and Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | | | | | - George Cope
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | | | | | - Raina Ramnath
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | - Simon C Satchell
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | - Rebecca R Foster
- Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom
| | - Kurt Ballmer-Hofer
- Biomolecular Research, Molecular Cell Biology, Paul Scherrer Institut, Villigen, Switzerland
| | - Lucy F Donaldson
- School of Physiology and Pharmacology and School of Life Sciences and
| | - Jonathan Barratt
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and
| | - Hans J Baelde
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - David O Bates
- Cancer Biology, Division of Oncology, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Andrew H J Salmon
- School of Physiology and Pharmacology and Academic Renal Unit, School of Clinical Science, University of Bristol, Bristol, United Kingdom;
| |
Collapse
|
18
|
Liu MW, Wang YH, Qian CY, Li H. Xuebijing exerts protective effects on lung permeability leakage and lung injury by upregulating Toll-interacting protein expression in rats with sepsis. Int J Mol Med 2014; 34:1492-504. [PMID: 25269519 PMCID: PMC4214342 DOI: 10.3892/ijmm.2014.1943] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 09/16/2014] [Indexed: 01/07/2023] Open
Abstract
Xuebijing (XBJ) is a type of traditional Tibetan medicine, and previous pharmacological studies have shown that the ethanol extract is derived from Chuanxiong, Chishao, Danshen and Honghua. Chuanxiong, Chishao, Danshen and Honghua possesses potent anti-inflammatory activity, and has been used in the treatment of inflammatory infectious diseases. In the present study, we investigated the effects of XBJ on pulmonary permeability and lung injury in cecal ligation and puncture (CLP)-induced sepsis in rats. A CLP sepsis model was established for the control and treatment groups, respectively. Approximately 2 h prior to surgery, an amount of 100 mg/kg XBJ injection was administered to the treatment group. Reverse transcription polymerase chain reaction (PT-PCR) and western blot analysis were used to examine the expression of Toll-interacting protein (Tollip), interleukin-1 receptor-associated kinase 1 (IRAK1), Toll-like receptor 4 (TLR4), nuclear factor-κB65 (NF-κB65) and TNF receptor-associated factor 6 (TRAF6) in lung tissue. ELISA was applied to detect changes of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), interleukin-4 (IL-4) and interleukin-10 (IL-10) levels in bronchoalveolar lavage (BAL) fluid, and intercellular adhesion molecule 1 (ICAM-1) and von Willebrand factor (vWF) in serum. The number of neutrophils, albumin and total cells in the BAL fluid were measured. For histological analysis, hematoxylin and eosin (H&E) stains were evaluated. Lung permeability, the wet/dry weight ratio (W/D) and the lung pathology score were determined following the induction of ALI by CLP for 24 h. The results demonstrated that XBJ upregulated Tollip expression and blocked the activity of IRAK1, TLR4, NF-κβ65 and TRAF6. Additionally, the number of neutrophils and total cells were significantly decreased in the XBJ group compared to that in the control group. Lung permeability, the wet/dry weight ratio (W/D) and the lung pathology score were significantly decreased in the XBJ group. The histological results also demonstrated the attenuation effect of XBJ on CLP-induced lung inflammation. The results of the present study indicated that XBJ has a significantly reduced CLP-induced lung permeability by upregulating Tollip expression. The protective effects of XBJ suggest its therapeutic potential in CLP-induced acute lung injury treatment.
Collapse
Affiliation(s)
- Ming-Wei Liu
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Yun-Hui Wang
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Chuan-Yun Qian
- Department of Emergency, The First Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Hui Li
- Surgical Intensive Care Unit, The Second Hospital Affiliated To Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| |
Collapse
|
19
|
Abstract
PURPOSE OF REVIEW The vascular endothelial growth factor (VEGF) system is a multifarious network and an exemplar of an intraglomerular signalling pathway. Here, we review recent advances that highlight the subtle nature of the renal VEGF system and its influencers. RECENT FINDINGS The VEGF system is no longer considered as a simple paracrine, ligand-receptor interaction under the regulatory control of a soluble 'decoy', soluble fms-like tyrosine kinase-1 (sFLT1). Rather, the abundantly expressed, podocyte-derived VEGF isoform, VEGF-A, is now recognized to mediate both paracrine effects across the filtration barrier and autocrine actions, functioning to preserve the integrity of the cells from which it arises. Autocrine actions of the podocyte VEGF system extend beyond those of the VEGF-A isoform, however, with sFLT1 itself now appreciated as regulating podocyte morphology by binding to lipid microdomains. These and other functions of the VEGF system are profoundly affected by the presence, nature and abundance of influencers both intrinsic and extrinsic to the pathway, the latter most readily exemplified by the role of the cytokine in the diabetic kidney. SUMMARY The glomerular VEGF system plays a delicate, yet critical, role in preserving renal homeostasis. It may be intricate, but 'in all things of nature there is something of the marvellous'.
Collapse
|
20
|
Hayman SR, Calle JC, Jatoi A, Craici IM, Wagner SJ, Weaver AL, Greene EL, Grande JP, Garovic VD. Urinary podocyte excretion and proteinuria in patients treated with antivascular endothelial growth factor therapy for solid tumor malignancies. Oncology 2014; 86:271-8. [PMID: 24902997 DOI: 10.1159/000360180] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 01/29/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Urinary podocyte excretion (podocyturia) may function as a more specific marker of ongoing glomerular damage. This study sought to analyze the relationship between proteinuria and podocyturia in cancer patients treated with antivascular endothelial growth factor (anti-VEGF) agents. METHODS Thirty-seven patients treated with anti-VEGF medications were analyzed in a single-institution, cross-sectional study. Podocyte cultures were performed on random urine collections (50-100 ml), and podocytes were identified by positive podocin staining. The corresponding urine samples were analyzed for protein and creatinine (Cr) measurements. RESULTS Proteinuria ≥0.5 g/g Cr was found in 30% of the patients (median, 0.12; interquartile range, 0.04-0.86), and 62% had podocyturia. There was a significant difference in the amount of podocyturia between patients with proteinuria ≥0.5 g/g Cr and those with a value <0.5 g/g Cr (median podocyturia, 1.08 cells/mg Cr, range, 0-14.55 vs. 0.03 cells/mg Cr, range, 0-1.64, respectively; p < 0.001). A statistically significant correlation was observed between the cumulative dose of bevacizumab and both proteinuria (r = 0.48, p = 0.004) and podocyturia (r = 0.34, p = 0.045) as well as between proteinuria and podocyturia (r = 0.63, p < 0.001), suggesting that these are mechanistically related. DISCUSSION Ongoing podocyte loss may be mechanistically related to the onset and severity of proteinuria in patients treated with anti-VEGF agents.
Collapse
|
21
|
Beazley-Long N, Hua J, Jehle T, Hulse RP, Dersch R, Lehrling C, Bevan H, Qiu Y, Lagrèze WA, Wynick D, Churchill AJ, Kehoe P, Harper SJ, Bates DO, Donaldson LF. VEGF-A165b is an endogenous neuroprotective splice isoform of vascular endothelial growth factor A in vivo and in vitro. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:918-29. [PMID: 23838428 DOI: 10.1016/j.ajpath.2013.05.031] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 05/19/2013] [Accepted: 05/31/2013] [Indexed: 01/13/2023]
Abstract
Vascular endothelial growth factor (VEGF) A is generated as two isoform families by alternative RNA splicing, represented by VEGF-A165a and VEGF-A165b. These isoforms have opposing actions on vascular permeability, angiogenesis, and vasodilatation. The proangiogenic VEGF-A165a isoform is neuroprotective in hippocampal, dorsal root ganglia, and retinal neurons, but its propermeability, vasodilatatory, and angiogenic properties limit its therapeutic usefulness. In contrast, a neuroprotective effect of endogenous VEGF-A165b on neurons would be advantageous for neurodegenerative pathologies. Endogenous expression of human and rat VEGF-A165b was detected in hippocampal and cortical neurons. VEGF-A165b formed a significant proportion of total VEGF-A in rat brain. Recombinant human VEGF-A165b exerted neuroprotective effects in response to multiple insults, including glutamatergic excitotoxicity in hippocampal neurons, chemotherapy-induced cytotoxicity of dorsal root ganglion neurons, and retinal ganglion cells (RGCs) in rat retinal ischemia-reperfusion injury in vivo. Neuroprotection was dependent on VEGFR2 and MEK1/2 activation but not on p38 or phosphatidylinositol 3-kinase activation. Recombinant human VEGF-A165b is a neuroprotective agent that effectively protects both peripheral and central neurons in vivo and in vitro through VEGFR2, MEK1/2, and inhibition of caspase-3 induction. VEGF-A165b may be therapeutically useful for pathologies that involve neuronal damage, including hippocampal neurodegeneration, glaucoma diabetic retinopathy, and peripheral neuropathy. The endogenous nature of VEGF-A165b expression suggests that non-isoform-specific inhibition of VEGF-A (for antiangiogenic reasons) may be damaging to retinal and sensory neurons.
Collapse
Affiliation(s)
- Nicholas Beazley-Long
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
SRPK1 inhibition in vivo: modulation of VEGF splicing and potential treatment for multiple diseases. Biochem Soc Trans 2012; 40:831-5. [PMID: 22817743 DOI: 10.1042/bst20120051] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
SRPK1 (serine-arginine protein kinase 1) is a protein kinase that specifically phosphorylates proteins containing serine-arginine-rich domains. Its substrates include a family of SR proteins that are key regulators of mRNA AS (alternative splicing). VEGF (vascular endothelial growth factor), a principal angiogenesis factor contains an alternative 3' splice site in the terminal exon that defines a family of isoforms with a different amino acid sequence at the C-terminal end, resulting in anti-angiogenic activity in the context of VEGF165-driven neovascularization. It has been shown recently in our laboratories that SRPK1 regulates the choice of this splice site through phosphorylation of the splicing factor SRSF1 (serine/arginine-rich splicing factor 1). The present review summarizes progress that has been made to understand how SRPK1 inhibition may be used to manipulate the balance of pro- and anti-angiogenic VEGF isoforms in animal models in vivo and therefore control abnormal angiogenesis and other pathophysiological processes in multiple disease states.
Collapse
|
23
|
Abstract
Anti-angiogenic vascular endothelial growth factor A (VEGF) 165b and pro-angiogenic VEGF 165 are generated from the same transcript, and their relative amounts are dependent on alternative splicing. The role of VEGF 165b has not been investigated in as much detail as VEGF 165, although it appears to be highly expressed in non-angiogenic tissues and, in contrast with VEGF 165, is downregulated in tumors and other pathologies associated with abnormal neovascularization such as diabetic retinopathy or Denys Drash syndrome. VEGF 165b inhibits VEGFR2 signaling by inducing differential phosphorylation, and it can be used to block angiogenesis in in vivo models of tumorigenesis and angiogenesis-related eye disease. Recent reports have identified three serine/arginine-rich proteins, SRSF1, SRSF2 and SRSF6, and studied their role in regulating terminal splice-site selection. Since the balance of VEGF isoforms is lost in cancer and angiogenesis-related conditions, control of VEGF splicing could also be used as a basis for therapy in these diseases.
Collapse
Affiliation(s)
- Maria Peiris-Pagès
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
| |
Collapse
|
24
|
Oltean S, Neal CR, Mavrou A, Patel P, Ahad T, Alsop C, Lee T, Sison K, Qiu Y, Harper SJ, Bates DO, Salmon AHJ. VEGF165b overexpression restores normal glomerular water permeability in VEGF164-overexpressing adult mice. Am J Physiol Renal Physiol 2012; 303:F1026-36. [PMID: 22811490 DOI: 10.1152/ajprenal.00410.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Vascular endothelial growth factor (VEGF)-A, a family of differentially spliced proteins produced by glomerular podocytes, maintains glomerular filtration barrier function. The expression of VEGF molecules is altered in human nephropathy. We aimed to determine the roles of the angiogenic VEGF(164) isoform, and the antiangiogenic VEGF(165)b isoform in mature, adult glomeruli in vivo using conditional, inducible transgenic overexpression systems in mice. Podocyte-specific VEGF(164) overexpression (up to 100 days) was induced by oral administration of doxycycline to adult podocin-rtTA/TetO-VEGF(164) double transgenic mice. The consequences of simultaneous overexpression of VEGF(164) and VEGF(165)b were assessed in triple-transgenic podocin-rtTA/TetO-VEGF(164)/nephrin-VEGF(165)b mice. Persistent VEGF(164) overexpression did not cause proteinuria but did increase glomerular ultrafiltration coefficient between days 3 and 7. Despite persistently increased VEGF(164) levels, glomerular ultrafiltration coefficient normalized by day 14 and remained normal up to 100 days. Decreased subpodocyte space (SPS) coverage of the glomerular capillary wall accompanied increased glomerular hydraulic conductivity in VEGF(164)-overexpressing mice. The changes in glomerular ultrafiltration coefficient and SPS coverage induced by 7 days of overexpression of VEGF(164) were not present in triple transgenic VEGF(164) and VEGF(165)b overexpressing mice. These results indicate that 1) the adult mouse glomerulus is relatively resistant to induced VEGF(164) overexpression. VEGF(164) overexpression altered glomerular permeability but did not cause proteinuria in these mature, adult animals; 2) the SPS is a dynamic VEGF-responsive modulator of glomerular function; and 3) the balance of VEGF isoforms plays a critical role in the regulation of glomerular permeability. VEGF(165)b is capable of preventing VEGF(164)-induced changes in glomerular permeability and ultrastructure in vivo.
Collapse
Affiliation(s)
- Sebastian Oltean
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Univ. of Bristol, Preclinical Veterinary School, Southwell St., Bristol, United Kingdom. BS2 8EJ
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Caires KC, de Avila JM, Cupp AS, McLean DJ. VEGFA family isoforms regulate spermatogonial stem cell homeostasis in vivo. Endocrinology 2012; 153:887-900. [PMID: 22147017 PMCID: PMC3275389 DOI: 10.1210/en.2011-1323] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The objective of the present study was to investigate vascular endothelial growth factor A (VEGFA) isoform regulation of cell fate decisions of spermatogonial stem cells (SSC) in vivo. The expression pattern and cell-specific distribution of VEGF isoforms, receptors, and coreceptors during testis development postnatal d 1-180 suggest a nonvascular function for VEGF regulation of early germ cell homeostasis. Populations of undifferentiated spermatogonia present shortly after birth were positive for VEGF receptor activation as demonstrated by immunohistochemical analysis. Thus, we hypothesized that proangiogenic isoforms of VEGF (VEGFA(164)) stimulate SSC self-renewal, whereas antiangiogenic isoforms of VEGF (VEGFA(165)b) induce differentiation of SSC. To test this hypothesis, we used transplantation to assay the stem cell activity of SSC obtained from neonatal mice treated daily from postnatal d 3-5 with 1) vehicle, 2) VEGFA(164), 3) VEGFA(165)b, 4) IgG control, 5) anti-VEGFA(164), and 6) anti-VEGFA(165)b. SSC transplantation analysis demonstrated that VEGFA(164) supports self-renewal, whereas VEGFA(165)b stimulates differentiation of mouse SSC in vivo. Gene expression analysis of SSC-associated factors and morphometric analysis of germ cell populations confirmed the effects of treatment on modulating the biological activity of SSC. These findings indicate a nonvascular role for VEGF in testis development and suggest that a delicate balance between VEGFA(164) and VEGFA(165)b isoforms orchestrates the cell fate decisions of SSC. Future in vivo and in vitro experimentation will focus on elucidating the mechanisms by which VEGFA isoforms regulate SSC homeostasis.
Collapse
Affiliation(s)
- Kyle C Caires
- Department of Animal Sciences, Center for Reproductive Biology, Washington State University, Pullman, Washington 99164, USA
| | | | | | | |
Collapse
|
26
|
Amin EM, Oltean S, Hua J, Gammons MVR, Hamdollah-Zadeh M, Welsh GI, Cheung MK, Ni L, Kase S, Rennel ES, Symonds KE, Nowak DG, Royer-Pokora B, Saleem MA, Hagiwara M, Schumacher VA, Harper SJ, Hinton DR, Bates DO, Ladomery MR. WT1 mutants reveal SRPK1 to be a downstream angiogenesis target by altering VEGF splicing. Cancer Cell 2011; 20:768-80. [PMID: 22172722 PMCID: PMC3574979 DOI: 10.1016/j.ccr.2011.10.016] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 06/10/2011] [Accepted: 10/17/2011] [Indexed: 12/19/2022]
Abstract
Angiogenesis is regulated by the balance of proangiogenic VEGF(165) and antiangiogenic VEGF(165)b splice isoforms. Mutations in WT1, the Wilms' tumor suppressor gene, suppress VEGF(165)b and cause abnormal gonadogenesis, renal failure, and Wilms' tumors. In WT1 mutant cells, reduced VEGF(165)b was due to lack of WT1-mediated transcriptional repression of the splicing-factor kinase SRPK1. WT1 bound to the SRPK1 promoter, and repressed expression through a specific WT1 binding site. In WT1 mutant cells SRPK1-mediated hyperphosphorylation of the oncogenic RNA binding protein SRSF1 regulated splicing of VEGF and rendered WT1 mutant cells proangiogenic. Altered VEGF splicing was reversed by wild-type WT1, knockdown of SRSF1, or SRPK1 and inhibition of SRPK1, which prevented in vitro and in vivo angiogenesis and associated tumor growth.
Collapse
Affiliation(s)
- Elianna M Amin
- Centre for Research in Biomedicine, University of the West of England, Bristol, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
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
|
28
|
Bills VL, Salmon AH, Harper SJ, Overton TG, Neal CR, Jeffery B, Soothill PW, Bates DO. Impaired vascular permeability regulation caused by the VEGF165b splice variant in pre-eclampsia. BJOG 2011; 118:1253-61. [DOI: 10.1111/j.1471-0528.2011.02925.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
29
|
Affiliation(s)
- Janaka Karalliedde
- Unit for Metabolic Medicine, Cardiovascular Division, King's College, London, UK
| | | |
Collapse
|
30
|
Wyss HM, Henderson JM, Byfield FJ, Bruggeman LA, Ding Y, Huang C, Suh JH, Franke T, Mele E, Pollak MR, Miner JH, Janmey PA, Weitz DA, Miller RT. Biophysical properties of normal and diseased renal glomeruli. Am J Physiol Cell Physiol 2011; 300:C397-405. [PMID: 21123730 PMCID: PMC3063968 DOI: 10.1152/ajpcell.00438.2010] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 11/30/2010] [Indexed: 11/22/2022]
Abstract
The mechanical properties of tissues and cells including renal glomeruli are important determinants of their differentiated state, function, and responses to injury but are not well characterized or understood. Understanding glomerular mechanics is important for understanding renal diseases attributable to abnormal expression or assembly of structural proteins and abnormal hemodynamics. We use atomic force microscopy (AFM) and a new technique, capillary micromechanics, to measure the elastic properties of rat glomeruli. The Young's modulus of glomeruli was 2,500 Pa, and it was reduced to 1,100 Pa by cytochalasin and latunculin, and to 1,400 Pa by blebbistatin. Cytochalasin or latrunculin reduced the F/G actin ratios of glomeruli but did not disrupt their architecture. To assess glomerular biomechanics in disease, we measured the Young's moduli of glomeruli from two mouse models of primary glomerular disease, Col4a3(-/-) mice (Alport model) and Tg26(HIV/nl) mice (HIV-associated nephropathy model), at stages where glomerular injury was minimal by histopathology. Col4a3(-/-) mice express abnormal glomerular basement membrane proteins, and Tg26(HIV/nl) mouse podocytes have multiple abnormalities in morphology, adhesion, and cytoskeletal structure. In both models, the Young's modulus of the glomeruli was reduced by 30%. We find that glomeruli have specific and quantifiable biomechanical properties that are dependent on the state of the actin cytoskeleton and nonmuscle myosins. These properties may be altered early in disease and represent an important early component of disease. This increased deformability of glomeruli could directly contribute to disease by permitting increased distension with hemodynamic force or represent a mechanically inhospitable environment for glomerular cells.
Collapse
Affiliation(s)
- Hans M Wyss
- Physics, Harvard University, Cambridge, Massachusetts, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Harper SJ, Bates DO. Glomerular filtration barrier and molecular segregation: guilty as charged? J Am Soc Nephrol 2010; 21:2009-11. [PMID: 21071522 DOI: 10.1681/asn.2010101071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
|
32
|
|
33
|
|
34
|
Abstract
Vascular endothelial growth factors (VEGFs) are key regulators of permeability. The principal evidence behind how they increase vascular permeability in vivo and in vitro and the consequences of that increase are addressed here. Detailed analysis of the published literature has shown that in vivo and in vitro VEGF-mediated permeability differs in its time course, but has common involvement of many specific signalling pathways, in particular VEGF receptor-2 activation, calcium influx through transient receptor potential channels, activation of phospholipase C gamma and downstream activation of nitric oxide synthase. Pathways downstream of endothelial nitric oxide synthase appear to involve the guanylyl cyclase-mediated activation of the Rho–Rac pathway and subsequent involvement of junctional signalling proteins such as vascular endothelial cadherin and the tight junctional proteins zona occludens and occludin linked to the actin cytoskeleton. The signalling appears to be co-ordinated through spatial organization of the cascade into a signalplex, and arguments for why this may be important are considered. Many proteins have been identified to be involved in the regulation of vascular permeability by VEGF, but still the mechanisms through which these are thought to interact to control permeability are dependent on the experimental system, and a synthesis of existing data reveals that in intact vessels the co-ordination of the pathways is still not understood.
Collapse
Affiliation(s)
- David O Bates
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, School of Veterinary Sciences, Bristol Heart Institute, University of Bristol, Southwell Street, Bristol, UK.
| |
Collapse
|