51
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Poosti F, Bansal R, Yazdani S, Prakash J, Beljaars L, van den Born J, de Borst MH, van Goor H, Hillebrands JL, Poelstra K. Interferon gamma peptidomimetic targeted to interstitial myofibroblasts attenuates renal fibrosis after unilateral ureteral obstruction in mice. Oncotarget 2018; 7:54240-54252. [PMID: 27509062 PMCID: PMC5342338 DOI: 10.18632/oncotarget.11095] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/20/2016] [Indexed: 01/06/2023] Open
Abstract
Renal fibrosis cannot be adequately treated since anti-fibrotic treatment is lacking. Interferon-γ is a pro-inflammatory cytokine with anti-fibrotic properties. Clinical use of interferon-γ is hampered due to inflammation-mediated systemic side effects. We used an interferon-γ peptidomimetic (mimγ) lacking the extracellular IFNγReceptor recognition domain, and coupled it to the PDGFβR-recognizing peptide BiPPB. Here we tested the efficacy of mimγ-BiPPB (referred to as “Fibroferon”) targeted to PDGFβR-overexpressing interstitial myofibroblasts to attenuate renal fibrosis without inducing inflammation-mediated side effects in the mouse unilateral ureter obstruction model. Unilateral ureter obstruction induced renal fibrosis characterized by significantly increased α-SMA, TGFβ1, fibronectin, and collagens I and III protein and/or mRNA expression. Fibroferon treatment significantly reduced expression of these fibrotic markers. Compared to full-length IFNγ, anti-fibrotic effects of Fibroferon were more pronounced. Unilateral ureter obstruction-induced lymphangiogenesis was significantly reduced by Fibroferon but not full-length IFNγ. In contrast to full-length IFNγ, Fibroferon did not induce IFNγ-related side-effects as evidenced by preserved low-level brain MHC II expression (similar to vehicle), lowered plasma triglyceride levels, and improved weight gain after unilateral ureter obstruction. In conclusion, compared to full-length IFNγ, the IFNγ-peptidomimetic Fibroferon targeted to PDGFβR-overexpressing myofibroblasts attenuates renal fibrosis in the absence of IFNγ-mediated adverse effects.
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Affiliation(s)
- Fariba Poosti
- Department of Pathology and Medical Biology, Division of Pathology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Microbiology and Immunology, Laboratory of Molecular Immunology, Rega Institute, KU Leuven, Belgium
| | - Ruchi Bansal
- Department of Biomaterials Science and Technology, Division of Targeted Therapeutics, MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Saleh Yazdani
- Department of Biomaterials Science and Technology, Division of Targeted Therapeutics, MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Jai Prakash
- Department of Biomaterials Science and Technology, Division of Targeted Therapeutics, MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Leonie Beljaars
- Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands
| | - Jacob van den Born
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Harry van Goor
- Department of Pathology and Medical Biology, Division of Pathology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology, Division of Pathology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Klaas Poelstra
- Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands
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52
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Abstract
Kidney cell death plays a key role in the progression of life-threatening renal diseases, such as acute kidney injury and chronic kidney disease. Injured and dying epithelial and endothelial cells take part in complex communication with the innate immune system, which drives the progression of cell death and the decrease in renal function. To improve our understanding of kidney cell death dynamics and its impact on renal disease, a study approach is needed that facilitates the visualization of renal function and morphology in real time. Intravital multiphoton microscopy of the kidney has been used for more than a decade and made substantial contributions to our understanding of kidney physiology and pathophysiology. It is a unique tool that relates renal structure and function in a time- and spatial-dependent manner. Basic renal function, such as microvascular blood flow regulation and glomerular filtration, can be determined in real time and homeostatic alterations, which are linked inevitably to cell death and can be depicted down to the subcellular level. This review provides an overview of the available techniques to study kidney dysfunction and inflammation in terms of cell death in vivo, and addresses how this novel approach can be used to improve our understanding of cell death dynamics in renal disease.
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53
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Loganathan K, Salem Said E, Winterrowd E, Orebrand M, He L, Vanlandewijck M, Betsholtz C, Quaggin SE, Jeansson M. Angiopoietin-1 deficiency increases renal capillary rarefaction and tubulointerstitial fibrosis in mice. PLoS One 2018; 13:e0189433. [PMID: 29293543 PMCID: PMC5749705 DOI: 10.1371/journal.pone.0189433] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/24/2017] [Indexed: 01/06/2023] Open
Abstract
Presence of tubulointerstitial fibrosis is predictive of progressive decline in kidney function, independent of its underlying cause. Injury to the renal microvasculature is a major factor in the progression of fibrosis and identification of factors that regulate endothelium in fibrosis is desirable as they might be candidate targets for treatment of kidney diseases. The current study investigates how loss of Angipoietin-1 (Angpt1), a ligand for endothelial tyrosine-kinase receptor Tek (also called Tie2), affects tubulointerstitial fibrosis and renal microvasculature. Inducible Angpt1 knockout mice were subjected to unilateral ureteral obstruction (UUO) to induce fibrosis, and kidneys were collected at different time points up to 10 days after obstruction. Staining for aSMA showed that Angpt1 deficient kidneys had significantly more fibrosis compared to wildtype mice 3, 6, and 10 days after UUO. Further investigation 3 days after UUO showed a significant increase of Col1a1 and vimentin in Angpt1 deficient mice, as well as increased gene expression of Tgfb1, Col1a1, Fn1, and CD44. Kidney injury molecule 1 (Kim1/Havcr1) was significantly more increased in Angpt1 deficient mice 1 and 3 days after UUO, suggesting a more severe injury early in the fibrotic process in Angpt1 deficient mice. Staining for endomucin showed that capillary rarefaction was evident 3 days after UUO and Angpt1 deficient mice had significantly less capillaries 6 and 10 days after UUO compared to UUO kidneys in wildtype mice. RNA sequencing revealed downregulation of several markers for endothelial cells 3 days after UUO, and that Angpt1 deficient mice had a further downregulation of Emcn, Plvap, Pecam1, Erg, and Tek. Our results suggest that loss of Angpt1 is central in capillary rarefaction and fibrogenesis and propose that manipulations to maintain Angpt1 levels may slow down fibrosis progression.
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Affiliation(s)
| | - Ebtisam Salem Said
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Emily Winterrowd
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Martina Orebrand
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Liqun He
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, China
| | - Michael Vanlandewijck
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Integrated Cardio Metabolic Centre, Karolinska Institutet, Huddinge, Sweden
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Integrated Cardio Metabolic Centre, Karolinska Institutet, Huddinge, Sweden
| | - Susan E. Quaggin
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL, United States of America
- Division of Nephrology and Hypertension, Northwestern University, Chicago, IL, United States of America
| | - Marie Jeansson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- * E-mail:
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54
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Kim Y, Shim SC. Wolves Trapped in the NETs–The Pathogenesis of Lupus Nephritis. JOURNAL OF RHEUMATIC DISEASES 2018. [DOI: 10.4078/jrd.2018.25.2.81] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Young Kim
- Division of Internal Medicine, Daejeon Veterans Hospital, Daejeon, Korea
| | - Seung Cheol Shim
- Division of Rheumatology, Department of Internal Medicine, Daejeon Rheumatoid and Degenerative Arthritis Center, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea
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55
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Hultström M, Becirovic-Agic M, Jönsson S. Comparison of acute kidney injury of different etiology reveals in-common mechanisms of tissue damage. Physiol Genomics 2017; 50:127-141. [PMID: 29341864 DOI: 10.1152/physiolgenomics.00037.2017] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Acute kidney injury (AKI) is a syndrome of reduced glomerular filtration rate and urine production caused by a number of different diseases. It is associated with renal tissue damage. This tissue damage can cause tubular atrophy and interstitial fibrosis that leads to nephron loss and progression of chronic kidney disease (CKD). This review describes the in-common mechanisms behind tissue damage in AKI caused by different underlying diseases. Comparing six high-quality microarray studies of renal gene expression after AKI in disease models (gram-negative sepsis, gram-positive sepsis, ischemia-reperfusion, malignant hypertension, rhabdomyolysis, and cisplatin toxicity) identified 5,254 differentially expressed genes in at least one of the AKI models; 66% of genes were found only in one model, showing that there are unique features to AKI depending on the underlying disease. There were in-common features in the form of four genes that were differentially expressed in all six models, 49 in at least five, and 215 were found in common between at least four models. Gene ontology enrichment analysis could be broadly categorized into the injurious processes hypoxia, oxidative stress, and inflammation, as well as the cellular outcomes of cell death and tissue remodeling in the form of epithelial-to-mesenchymal transition. Pathway analysis showed that MYC is a central connection in the network of activated genes in-common to AKI, which suggests that it may be a central regulator of renal gene expression in tissue injury during AKI. The outlining of this molecular network may be useful for understanding progression from AKI to CKD.
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Affiliation(s)
- Michael Hultström
- Integrative Physiology, Department of Medical Cell Biology, Uppsala University , Uppsala , Sweden.,Anaesthesia and Intensive Care Medicine, Department of Surgical Sciences, Uppsala University , Uppsala , Sweden
| | - Mediha Becirovic-Agic
- Integrative Physiology, Department of Medical Cell Biology, Uppsala University , Uppsala , Sweden
| | - Sofia Jönsson
- Integrative Physiology, Department of Medical Cell Biology, Uppsala University , Uppsala , Sweden
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56
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Afsar B, Afsar RE, Dagel T, Kaya E, Erus S, Ortiz A, Covic A, Kanbay M. Capillary rarefaction from the kidney point of view. Clin Kidney J 2017; 11:295-301. [PMID: 29988260 PMCID: PMC6007395 DOI: 10.1093/ckj/sfx133] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/04/2017] [Indexed: 12/18/2022] Open
Abstract
Capillary rarefaction is broadly defined as a reduction in vascular density. Capillary rarefaction in the kidneys is thought to promote hypoxia, impair hemodynamic responses and predispose to chronic kidney disease (CKD) progression and hypertension development. Various mechanisms have been suggested to play a role in the development of capillary rarefaction, including inflammation, an altered endothelial-tubular epithelial cell crosstalk, a relative deficiency in angiogenic growth factors, loss of pericytes, increased activity of Transforming growth factor -β1 and thrombospondin-1, vitamin D deficiency, a link to lymphatic neoangiogenesis and INK4a/ARF (Cylin-dependent kinase inhibitor 2a; CDKN2A). In this review, we summarize the tools available to monitor capillary rarefaction noninvasively in the clinic, the contribution of capillary rarefaction to CKD and hypertension, the known mechanisms of capillary rarefaction, and potential future strategies to attenuate capillary rarefaction and reduce its negative impact. Therapeutic strategies to be explored in more detail include optimization of antihypertensive therapy, vitamin D receptor activators, sirtuin 1 activators, Hypoxia inducible factor prolyl hydroxylase inhibitors and stem cell therapy.
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Affiliation(s)
- Baris Afsar
- Division of Nephrology, Department of Internal Medicine, Suleyman Demirel University School of Medicine, Isparta, Turkey
| | - Rengin E Afsar
- Division of Nephrology, Department of Internal Medicine, Suleyman Demirel University School of Medicine, Isparta, Turkey
| | - Tuncay Dagel
- Department of Nephrology, Koc University Hospital, Istanbul, Turkey
| | - Ege Kaya
- Koc University School of Medicine, Istanbul, Turkey
| | - Suat Erus
- Department of Thoracic Surgery, Koc University Hospital, Istanbul, Turkey
| | - Alberto Ortiz
- Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Fundación Renal Iñigo Alvarez de Toledo, Madrid, Spain
| | - Adrian Covic
- Department of Nephrology, Grigore T. Popa University of Medicine and Pharmacy, Iasi, Romania
| | - Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
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57
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Schmitt R, Melk A. Molecular mechanisms of renal aging. Kidney Int 2017; 92:569-579. [DOI: 10.1016/j.kint.2017.02.036] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/05/2017] [Accepted: 02/14/2017] [Indexed: 12/31/2022]
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58
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Zhong J, Yang HC, Fogo AB. A perspective on chronic kidney disease progression. Am J Physiol Renal Physiol 2016; 312:F375-F384. [PMID: 27974318 DOI: 10.1152/ajprenal.00266.2016] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 11/29/2016] [Accepted: 12/08/2016] [Indexed: 12/24/2022] Open
Abstract
Chronic kidney disease (CKD) will progress to end stage without treatment, but the decline of renal function may not be linear. Compared with glomerular filtration rate and proteinuria, new surrogate markers, such as kidney injury molecule-1, neutrophil gelatinase-associated protein, apolipoprotein A-IV, and soluble urokinase receptor, may allow potential intervention and treatment in the earlier stages of CKD, which could be useful for clinical trials. New omic-based technologies reveal potential new genomic and epigenomic mechanisms that appear different from those causing the initial disease. Various clinical studies also suggest that acute kidney injury is a major risk for progressive CKD. To ameliorate the progression of CKD, the first step is optimizing renin-angiotensin-aldosterone system blockade. New drugs targeting endothelin, transforming growth factor-β, oxidative stress, and inflammatory- and cell-based regenerative therapy may have add-on benefit.
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Affiliation(s)
- Jianyong Zhong
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Hai-Chun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Agnes B Fogo
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee; .,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee; and.,Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
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59
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Jumar A, Harazny JM, Ott C, Friedrich S, Kistner I, Striepe K, Schmieder RE. Retinal Capillary Rarefaction in Patients with Type 2 Diabetes Mellitus. PLoS One 2016; 11:e0162608. [PMID: 27935938 PMCID: PMC5147800 DOI: 10.1371/journal.pone.0162608] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/25/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose In diabetes mellitus type 2, capillary rarefaction plays a pivotal role in the pathogenesis of end-organ damage. We investigated retinal capillary density in patients with early disease. Methods This cross-sectional study compares retinal capillary rarefaction determined by intercapillary distance (ICD) and capillary area (CapA), measured non-invasively and in vivo by scanning laser Doppler flowmetry, in 73 patients with type 2 diabetes, 55 healthy controls and 134 individuals with hypertension stage 1 or 2. Results In diabetic patients, ICD was greater (23.2±5.5 vs 20.2±4.2, p = 0.013) and CapA smaller (1592±595 vs 1821±652, p = 0.019) than in healthy controls after adjustment for differences in cardiovascular risk factors between the groups. Compared to hypertensive patients, diabetic individuals showed no difference in ICD (23.1±5.8, p = 0.781) and CapA (1556±649, p = 0.768). Conclusion In the early stage of diabetes type 2, patients showed capillary rarefaction compared to healthy individuals.
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Affiliation(s)
- Agnes Jumar
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Joanna M Harazny
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany.,Department of Pathophysiology, University of Warmia and Mazury Olsztyn, Poland
| | - Christian Ott
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Stefanie Friedrich
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Iris Kistner
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Kristina Striepe
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Roland E Schmieder
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
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60
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Gewin L, Zent R, Pozzi A. Progression of chronic kidney disease: too much cellular talk causes damage. Kidney Int 2016; 91:552-560. [PMID: 27773427 DOI: 10.1016/j.kint.2016.08.025] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/31/2016] [Accepted: 08/16/2016] [Indexed: 01/10/2023]
Abstract
Tubulointerstitial fibrosis, tubular atrophy, and peritubular capillary rarefaction are major hallmarks of chronic kidney disease. The tubulointerstitium consists of multiple cell components including tubular epithelial, mesenchymal (fibroblasts and pericytes), endothelial, and inflammatory cells. Crosstalk among these cell components is a key component in the pathogenesis of this complex disease. After severe or recurrent injury, the renal tubular epithelial cells undergo changes in structure and cell cycle that are accompanied by altered expression and production of cytokines. These cytokines contribute to the initiation of the fibrotic response by favoring activation of fibroblasts, recruitment of inflammatory cells, and loss of endothelial cells. This review focuses on how augmented growth factor and cytokine production induces epithelial crosstalk with cells in the interstitium to promote progressive tubulointerstitial fibrosis after renal injury.
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Affiliation(s)
- Leslie Gewin
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA; Veterans Affairs Medical Center, Nashville, Tennessee, USA
| | - Roy Zent
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA; Veterans Affairs Medical Center, Nashville, Tennessee, USA; Department of Cancer Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA.
| | - Ambra Pozzi
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee, USA; Veterans Affairs Medical Center, Nashville, Tennessee, USA; Department of Cancer Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA; Department of Molecular Physiology and Biophysics, Vanderbilt Medical Center, Nashville, Tennessee, USA
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61
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von Stillfried S, Apitzsch JC, Ehling J, Penzkofer T, Mahnken AH, Knüchel R, Floege J, Boor P. Contrast-enhanced CT imaging in patients with chronic kidney disease. Angiogenesis 2016; 19:525-35. [PMID: 27582011 DOI: 10.1007/s10456-016-9524-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 08/22/2016] [Indexed: 11/29/2022]
Abstract
Renal microvascular rarefaction characterizes chronic kidney disease (CKD). In murine models of CKD, micro-CT imaging reflected capillary rarefaction using quantification of renal relative blood volume (rBV). In addition, micro-CT imaging revealed morphological alterations of the intrarenal vasculature including reduced vascular branching and lumen diameter. Here, we retrospectively quantified rBV in contrast-enhanced CT angiography in patients and found that, compared to non-CKD patients, those with CKD and renal fibrosis had significantly reduced rBV in the renal cortex. rBV values closely mirrored capillary rarefaction in the corresponding nephrectomy specimens. In patients with follow-up CT angiography, reduction of renal function was paralleled by a decline in rBV. Using virtual autopsy, i.e., postmortem CT angiography, morphometry of intrarenal arteries in 3D-rendered CT images revealed significantly reduced arterial diameter and branching in CKD compared to non-CKD cases. In conclusion, in CKD patients, contrast-enhanced CT imaging with quantification of rBV correlates with functional renal vasculature, whereas virtual autopsy allows morphometric analyses of macrovascular changes. Importantly, the observed vascular alterations in CKD patients mirror those in animals with progressive CKD, suggesting a high relevance of animal models for studying vascular alterations in CKD and renal fibrosis.
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Affiliation(s)
- Saskia von Stillfried
- Institute of Pathology, Aachen University Hospital, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Jonas C Apitzsch
- Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Aachen, Germany.,Department of Diagnostic and Interventional Radiology, University Hospital, Philipps University Marburg, Marburg, Germany
| | - Josef Ehling
- Department of Experimental Molecular Imaging, University Clinic and Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany
| | - Tobias Penzkofer
- Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Aachen, Germany
| | - Andreas H Mahnken
- Department of Diagnostic and Interventional Radiology, RWTH Aachen University Hospital, Aachen, Germany.,Department of Diagnostic and Interventional Radiology, University Hospital, Philipps University Marburg, Marburg, Germany
| | - Ruth Knüchel
- Institute of Pathology, Aachen University Hospital, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Jürgen Floege
- Department of Nephrology, RWTH Aachen University Hospital, Aachen, Germany
| | - Peter Boor
- Institute of Pathology, Aachen University Hospital, Pauwelsstrasse 30, 52074, Aachen, Germany. .,Department of Nephrology, RWTH Aachen University Hospital, Aachen, Germany.
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62
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Kida Y, Zullo JA, Goligorsky MS. Endothelial sirtuin 1 inactivation enhances capillary rarefaction and fibrosis following kidney injury through Notch activation. Biochem Biophys Res Commun 2016; 478:1074-9. [PMID: 27524235 DOI: 10.1016/j.bbrc.2016.08.066] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 08/10/2016] [Indexed: 11/29/2022]
Abstract
Peritubular capillary (PTC) rarefaction along with tissue fibrosis is a hallmark of chronic kidney disease (CKD). However, molecular mechanisms of PTC loss have been poorly understood. Previous studies have demonstrated that functional loss of endothelial sirtuin 1 (SIRT1) impairs angiogenesis during development and tissue damage. Here, we found that endothelial SIRT1 dysfunction causes activation of endothelial Notch1 signaling, which leads to PTC rarefaction and fibrosis following kidney injury. In mice lacking functional SIRT1 in the endothelium (Sirt1 mutant), kidney injury enhanced apoptosis and senescence of PTC endothelial cells with impaired endothelial proliferation and expanded myofibroblast population and collagen deposition. Compared to wild-type kidneys, Sirt1 mutant kidneys up-regulated expression of Delta-like 4 (DLL4, a potent Notch1 ligand), Hey1 and Hes1 (Notch target genes), and Notch intracellular domain-1 (NICD1, active form of Notch1) in microvascular endothelial cells (MVECs) post-injury. Sirt1 mutant primary kidney MVECs reduced motility and vascular assembly and enhanced senescence compared to wild-type kidney MVECs. This difference in the phenotype was negated with Notch inhibition. Concurrent stimulation of DLL4 and transforming growth factor (TGF)-β1 increased trans-differentiation of primary kidney pericytes into myofibroblast more than TGF-β1 treatment alone. Collectively, these results indicate that endothelial SIRT1 counteracts PTC rarefaction by repression of Notch1 signaling and antagonizes fibrosis via suppression of endothelial DLL4 expression.
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Affiliation(s)
- Yujiro Kida
- Renal Research Institute, Department of Medicine, New York Medical College, Valhalla, NY, USA.
| | - Joseph A Zullo
- Renal Research Institute, Department of Medicine, New York Medical College, Valhalla, NY, USA; Renal Research Institute, Department of Physiology, New York Medical College, Valhalla, NY, USA
| | - Michael S Goligorsky
- Renal Research Institute, Department of Medicine, New York Medical College, Valhalla, NY, USA; Renal Research Institute, Department of Pharmacology, New York Medical College, Valhalla, NY, USA; Renal Research Institute, Department of Physiology, New York Medical College, Valhalla, NY, USA
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63
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Abstract
The longstanding focus in chronic kidney disease (CKD) research has been on the glomerulus, which is sensible because this is where glomerular filtration occurs, and a large proportion of progressive CKD is associated with significant glomerular pathology. However, it has been known for decades that tubular atrophy is also a hallmark of CKD and that it is superior to glomerular pathology as a predictor of glomerular filtration rate decline in CKD. Nevertheless, there are vastly fewer studies that investigate the causes of tubular atrophy, and fewer still that identify potential therapeutic targets. The purpose of this review is to discuss plausible mechanisms of tubular atrophy, including tubular epithelial cell apoptosis, cell senescence, peritubular capillary rarefaction and downstream tubule ischemia, oxidative stress, atubular glomeruli, epithelial-to-mesenchymal transition, interstitial inflammation, lipotoxicity and Na(+)/H(+) exchanger-1 inactivation. Once a a better understanding of tubular atrophy (and interstitial fibrosis) pathophysiology has been obtained, it might then be possible to consider tandem glomerular and tubular therapeutic strategies, in a manner similar to cancer chemotherapy regimens, which employ multiple drugs to simultaneously target different mechanistic pathways.
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64
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Yim HE, Yoo KH, Bae ES, Hong YS, Lee JW. Impaired angiogenesis in the enalapril-treated neonatal rat kidney. KOREAN JOURNAL OF PEDIATRICS 2016; 59:8-15. [PMID: 26893598 PMCID: PMC4753201 DOI: 10.3345/kjp.2016.59.1.8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/02/2015] [Accepted: 06/13/2015] [Indexed: 12/29/2022]
Abstract
PURPOSE Nephrogenesis is normally accompanied by a tightly regulated and efficient vascularization. We investigated the effect of angiotensin II inhibition on angiogenesis in the developing rat kidney. METHODS Newborn rat pups were treated with enalapril (30 mg/kg/day) or vehicle (control) for 7 days after birth. Renal histological changes were checked using Hematoxylin & Eosin staining. We also investigated the intrarenal expression of vascular endothelial growth factor (VEGF)-A, VEGF receptor 1 (VEGFR1), VEGFR2, platelet-derived growth factor (PDGF)-B, and PDGF receptor-β with Western blotting and immunohistochemical staining at postnatal day 8. Expression of the endothelial cell marker CD31 was examined to determine glomerular and peritubular capillary density. RESULTS Enalapril-treated rat kidneys showed disrupted tubules and vessels when compared with the control rat kidneys. In the enalapril-treated group, intrarenal VEGF-A protein expression was significantly higher, whereas VEGFR1 protein expression was lower than that in the control group (P<0.05). The expression of VEGFR2, PDGF-B, and PDGF receptor-β was not different between the 2 groups. The increased capillary CD31 expression on the western blots of enalapril-treated rat kidneys indicated that the total endothelial cell protein level was increased, while the cortical capillary density, assessed using CD31 immunohistochemical staining, was decreased. CONCLUSION Impaired VEGF-VEGFR signaling and altered capillary repair may play a role in the deterioration of the kidney vasculature after blocking of angiotensin II during renal development.
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Affiliation(s)
- Hyung Eun Yim
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
| | - Kee Hwan Yoo
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
| | - Eun Soo Bae
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
| | - Young Sook Hong
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
| | - Joo Won Lee
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
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Aplin AC, Nicosia RF. Hypoxia paradoxically inhibits the angiogenic response of isolated vessel explants while inducing overexpression of vascular endothelial growth factor. Angiogenesis 2016; 19:133-46. [PMID: 26748649 DOI: 10.1007/s10456-015-9493-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 12/30/2015] [Indexed: 01/08/2023]
Abstract
This study was designed to investigate how changes in O2 levels affected angiogenesis in vascular organ culture. Although hypoxia is a potent inducer of angiogenesis, aortic rings cultured in collagen paradoxically failed to produce an angiogenic response in 1-4 % O2. Additionally, aortic neovessels preformed in atmospheric O2 lost pericytes and regressed at a faster rate than control when exposed to hypoxia. Aortic explants remained viable in hypoxia and produced an angiogenic response when returned to atmospheric O2. Hypoxic aortic rings were unresponsive to VEGF, while increased oxygenation of the system dose-dependently enhanced VEGF-induced angiogenesis. Hypoxia-induced refractoriness to angiogenic stimulation was not restricted to the aorta because similar results were obtained with vena cava explants or isolated endothelial cells. Unlike endothelial cells, aorta-derived mural cells were unaffected by hypoxia. Hypoxia downregulated expression in aortic explants of key signaling molecules including VEGFR2, NRP1 and Prkc-beta while upregulating expression of VEGFR1. Medium conditioned by hypoxic cultures exhibited angiostatic and anti-VEGF activities likely mediated by sVEGFr1. Hypoxia reduced expression of VEGFR1 and VEGFR2 in endothelial cells while upregulating VEGFR1 in macrophages and VEGF in both macrophages and mural cells. Thus, changes in O2 levels profoundly affect the endothelial response to angiogenic stimuli. These results suggest that hypoxia-induced angiogenesis is fine-tuned by complex regulatory mechanisms involving not only production of angiogenic factors including VEGF but also differential regulation of VEGFR expression in different cell types and production of inhibitors of VEGF function such as sVEGFR1.
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Affiliation(s)
- Alfred C Aplin
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Roberto F Nicosia
- Department of Pathology, University of Washington, Seattle, WA, USA. .,Pathology and Laboratory Medicine Service (S-113-Lab), VA Puget Sound Health Care System, Seattle, WA, USA.
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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.
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Abstract
Despite marked improvements in the survival of patients with severe lupus nephritis over the past 50 years, the rate of complete clinical remission after immune suppression therapy is <50% and renal impairment still occurs in 40% of affected patients. An appreciation of the factors that lead to the development of chronic kidney disease following acute or subacute renal injury in patients with systemic lupus erythematosus is beginning to emerge. Processes that contribute to end-stage renal injury include continuing inflammation, activation of intrinsic renal cells, cell stress and hypoxia, metabolic abnormalities, aberrant tissue repair and tissue fibrosis. A deeper understanding of these processes is leading to the development of novel or adjunctive therapies that could protect the kidney from the secondary non-immune consequences of acute injury. Approaches based on a molecular-proteomic-lipidomic classification of disease should yield new information about the functional basis of disease heterogeneity so that the most effective and least toxic treatment regimens can be formulated for individual patients.
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68
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Muñoz-Félix JM, González-Núñez M, Martínez-Salgado C, López-Novoa JM. TGF-β/BMP proteins as therapeutic targets in renal fibrosis. Where have we arrived after 25 years of trials and tribulations? Pharmacol Ther 2015; 156:44-58. [PMID: 26493350 DOI: 10.1016/j.pharmthera.2015.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The understanding of renal fibrosis in chronic kidney disease (CKD) remains as a challenge. More than 10% of the population of developed countries suffer from CKD. Proliferation and activation of myofibroblasts and accumulation of extracellular matrix proteins are the main features of kidney fibrosis, a process in which a large number of cytokines are involved. Targeting cytokines responsible for kidney fibrosis development might be an important strategy to face the problem of CKD. The increasing knowledge of the signaling pathway network of the transforming growth factor beta (TGF-β) superfamily members, such as the profibrotic cytokine TGF-β1 or the bone morphogenetic proteins (BMPs), and their involvement in the regulation of kidney fibrosis, has stimulated numerous research teams to look for potential strategies to inhibit profibrotic cytokines or to enhance the anti-fibrotic actions of other cytokines. The consequence of all these studies is a better understanding of all these canonical (Smad-mediated) and non-canonical signaling pathways. In addition, the different receptors involved for signaling of each cytokine, the different combinations of type I-type II receptors, and the presence and function of co-receptors that can influence the biological response have been also described. However, are these studies leading to suitable strategies to block the appearance and progression of kidney fibrosis? In this review, we offer a critical perspective analyzing the achievements using the most important strategies developed up till now: TGF-β antibodies, chemical inhibitors of TGF-β receptors, miRNAs and signaling pathways and BMP agonists with a potential role as therapeutic molecules against kidney fibrosis.
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Affiliation(s)
- José M Muñoz-Félix
- Unidad de Fisiopatología Renal y Cardiovascular, Instituto Reina Sofía de Investigación Nefrológica, Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - María González-Núñez
- Unidad de Fisiopatología Renal y Cardiovascular, Instituto Reina Sofía de Investigación Nefrológica, Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Carlos Martínez-Salgado
- Unidad de Fisiopatología Renal y Cardiovascular, Instituto Reina Sofía de Investigación Nefrológica, Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain; Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL), Hospital Universitario de Salamanca, Salamanca, Spain
| | - José M López-Novoa
- Unidad de Fisiopatología Renal y Cardiovascular, Instituto Reina Sofía de Investigación Nefrológica, Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
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Boor P, Bábíčková J, Steegh F, Hautvast P, Martin IV, Djudjaj S, Nakagawa T, Ehling J, Gremse F, Bücher E, Eriksson U, van Roeyen CR, Eitner F, Lammers T, Floege J, Peutz-Kootstra CJ, Ostendorf T. Role of Platelet-Derived Growth Factor-CC in Capillary Rarefaction in Renal Fibrosis. THE AMERICAN JOURNAL OF PATHOLOGY 2015. [DOI: 10.1016/j.ajpath.2015.04.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Stefanska A, Eng D, Kaverina N, Duffield JS, Pippin JW, Rabinovitch P, Shankland SJ. Interstitial pericytes decrease in aged mouse kidneys. Aging (Albany NY) 2015; 7:370-82. [PMID: 26081073 PMCID: PMC4505164 DOI: 10.18632/aging.100756] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
With increasing age, the kidney undergoes characteristic changes in the glomerular and tubulo-interstitial compartments, which are ultimately accompanied by reduced kidney function. Studies have shown age-related loss of peritubular vessels. Normal peritubular vessel tone, function and survival depend on neighboring pericytes. Pericyte detachment leads to vascular damage, which can be accompanied by their differentiation to fibroblasts and myofibroblasts, a state that favors matrix production. To better understand the fate of pericytes in the aged kidney, 27 month-old mice were studied. Compared to 3 month-old young adult mice, aged kidneys showed a substantial decrease in capillaries, identified by CD31 staining, in both cortex and medulla. This was accompanied by a marked decrease in surrounding NG2+ / PDGFRβ+ pericytes. This decrease was more pronounced in the medulla. Capillaries devoid of pericytes were typically dilated in aged mice. Aged kidneys were also characterized by interstitial fibrosis due to increased collagen-I and -III staining. This was accompanied by an increase in the number of pericytes that acquired a pro-fibrotic phenotype, identified by increased PDGFRβ+ / αSMA+ staining. These findings are consistent with the decline in kidney interstitial pericytes as a critical step in the development of changes to the peritubular vasculature with aging, and accompanying fibrosis.
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Affiliation(s)
- Ania Stefanska
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Diana Eng
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Natalya Kaverina
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Jeremy S. Duffield
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
- Biogen Idec, Cambridge, MA 02142, USA
| | - Jeffrey W. Pippin
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Peter Rabinovitch
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
| | - Stuart J. Shankland
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, WA 98104, USA
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Boor P, Floege J. Renal allograft fibrosis: biology and therapeutic targets. Am J Transplant 2015; 15:863-86. [PMID: 25691290 DOI: 10.1111/ajt.13180] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 11/30/2014] [Accepted: 12/19/2014] [Indexed: 01/25/2023]
Abstract
Renal tubulointerstitial fibrosis is the final common pathway of progressive renal diseases. In allografts, it is assessed with tubular atrophy as interstitial fibrosis/tubular atrophy (IF/TA). IF/TA occurs in about 40% of kidney allografts at 3-6 months after transplantation, increasing to 65% at 2 years. The origin of renal fibrosis in the allograft is complex and includes donor-related factors, in particular in case of expanded criteria donors, ischemia-reperfusion injury, immune-mediated damage, recurrence of underlying diseases, hypertensive damage, nephrotoxicity of immunosuppressants, recurrent graft infections, postrenal obstruction, etc. Based largely on studies in the non-transplant setting, there is a large body of literature on the role of different cell types, be it intrinsic to the kidney or bone marrow derived, in mediating renal fibrosis, and the number of mediator systems contributing to fibrotic changes is growing steadily. Here we review the most important cellular processes and mediators involved in the progress of renal fibrosis, with a focus on the allograft situation, and discuss some of the challenges in translating experimental insights into clinical trials, in particular fibrosis biomarkers or imaging modalities.
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Affiliation(s)
- P Boor
- Division of Nephrology and Clinical Immunology, RWTH University of Aachen, Aachen, Germany; Department of Pathology, RWTH University of Aachen, Aachen, Germany; Institute of Molecular Biomedicine, Bratislava, Slovakia
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Poosti F, Bansal R, Yazdani S, Prakash J, Post E, Klok P, van den Born J, de Borst MH, van Goor H, Poelstra K, Hillebrands JL. Selective delivery of IFN-γ to renal interstitial myofibroblasts: a novel strategy for the treatment of renal fibrosis. FASEB J 2015; 29:1029-42. [PMID: 25466892 DOI: 10.1096/fj.14-258459] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Renal fibrosis leads to end-stage renal disease demanding renal replacement therapy because no adequate treatment exists. IFN-γ is an antifibrotic cytokine that may attenuate renal fibrosis. Systemically administered IFN-γ causes side effects that may be prevented by specific drug targeting. Interstitial myofibroblasts are the effector cells in renal fibrogenesis. Here, we tested the hypothesis that cell-specific delivery of IFN-γ to platelet-derived growth factor receptor β (PDGFRβ)-expressing myofibroblasts attenuates fibrosis in an obstructive nephropathy [unilateral ureteral obstruction (UUO)] mouse model. PEGylated IFN-γ conjugated to PDGFRβ-recognizing peptide [(PPB)-polyethylene glycol (PEG)-IFN-γ] was tested in vitro and in vivo for antifibrotic properties and compared with free IFN-γ. PDGFRβ expression was >3-fold increased (P < 0.05) in mouse fibrotic UUO kidneys and colocalized with α-smooth muscle actin-positive (SMA(+)) myofibroblasts. In vitro, PPB-PEG-IFN-γ significantly inhibited col1a1, col1a2, and α-SMA mRNA expression in TGF-β-activated NIH3T3 fibroblasts (P < 0.05). In vivo, PPB-PEG-IFN-γ specifically accumulated in PDGFRβ-positive myofibroblasts. PPB-PEG-IFN-γ treatment significantly reduced renal collagen I, fibronectin, and α-SMA mRNA and protein expression. Compared with vehicle treatment, PPB-PEG-IFN-γ preserved tubular morphology, reduced interstitial T-cell infiltration, and attenuated lymphangiogenesis (all P < 0.05) without affecting peritubular capillary density. PPB-PEG-IFN-γ reduced IFN-γ-related side effects as manifested by reduced major histocompatibility complex class II expression in brain tissue (P < 0.05 vs. free IFN-γ). Our findings demonstrate that specific targeting of IFN-γ to PDGFRβ-expressing myofibroblasts attenuates renal fibrosis and reduces systemic adverse effects.
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Affiliation(s)
- Fariba Poosti
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Ruchi Bansal
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Saleh Yazdani
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Jai Prakash
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Eduard Post
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Pieter Klok
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Jacob van den Born
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Martin H de Borst
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Harry van Goor
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Klaas Poelstra
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
| | - Jan-Luuk Hillebrands
- *Department of Pathology and Medical Biology, Division of Pathology, Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, and Department of Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands; and MIRA Institute, University of Twente, Enschede, The Netherlands
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Efficacy and safety of eculizumab in atypical hemolytic uremic syndrome from 2-year extensions of phase 2 studies. Kidney Int 2015; 87:1061-73. [PMID: 25651368 PMCID: PMC4424817 DOI: 10.1038/ki.2014.423] [Citation(s) in RCA: 288] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 09/30/2014] [Accepted: 10/30/2014] [Indexed: 12/11/2022]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare, possibly life-threatening disease characterized by platelet activation, hemolysis and thrombotic microangiopathy (TMA) leading to renal and other end-organ damage. We originally conducted two phase 2 studies (26 weeks and 1 year) evaluating eculizumab, a terminal complement inhibitor, in patients with progressing TMA (trial 1) and those with long duration of aHUS and chronic kidney disease (trial 2). The current analysis assessed outcomes after 2 years (median eculizumab exposure 100 and 114 weeks, respectively). At all scheduled time points, eculizumab inhibited terminal complement activity. In trial 1 with 17 patients, the platelet count was significantly improved from baseline, and hematologic normalization was achieved in 13 patients at week 26, and in 15 patients at both 1 and 2 years. The estimated glomerular filtration rate (eGFR) was significantly improved compared with baseline and year 1. In trial 2 with 20 patients, TMA event-free status was achieved by 16 patients at week 26, 17 patients at year 1, and 19 patients at year 2. Criteria for hematologic normalization were met by 18 patients at each time point. Improvement of 15 ml/min per 1.73 m2 or more in eGFR was achieved by 1 patient at week 26, 3 patients at 1 year, and 8 patients at 2 years. The mean change in eGFR was not significant compared with baseline, week 26, or year 1. Eculizumab was well tolerated, with no new safety concerns or meningococcal infections. Thus, a 2-year analysis found that the earlier clinical benefits achieved by eculizumab treatment of aHUS were maintained at 2 years of follow-up.
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74
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Edwards-Richards A, DeFreitas M, Katsoufis CP, Seeherunvong W, Sasaki N, Freundlich M, Zilleruelo G, Abitbol CL. Capillary rarefaction: an early marker of microvascular disease in young hemodialysis patients. Clin Kidney J 2014; 7:569-74. [PMID: 25859374 PMCID: PMC4389142 DOI: 10.1093/ckj/sfu106] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 09/22/2014] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Pediatric patients with chronic kidney disease (CKD) are at increased risk of early cardiovascular disease and premature death. Abnormalities in microvascular structure and function may presage end-organ damage including vascular calcification and myocardial ischemia associated with disordered mineral metabolism. Early detection of microvascular rarefaction (reduced density of capillaries) may identify at-risk patients and prompt timely therapeutic interventions. Our objective was to study capillary rarefaction in pediatric hemodialysis (HD) patients and to determine possible associations with mineral metabolism and cardiac risk biomarkers. METHODS Capillary density (CD) was measured by nailfold capillaroscopy in 19 pediatric HD patients and 20 healthy controls. Demographic and biochemical markers were collected at entry and 6-month follow-up. RESULTS CD was significantly decreased in HD patients compared with controls with a deficit of 24 and 31% at baseline and subsequent follow-up. Maximal CD correlated significantly with intact parathyroid hormone (iPTH) (r = -0.45; P = 0.005), serum calcium (r = -0.38; P = 0.02) and 25(OH) vitamin D levels (r = +0.36; P = 0.03) in HD patients. Capillary functional measures were similar to controls. By multivariate analysis, the primary negative determinants of CD were African American race and hyperparathyroidism; whereas, glomerular disease had a positive influence on capillary rarefaction (R (2) = 64.2% variance; P = 0.001). CONCLUSION Pediatric HD patients demonstrate a 'structural deficit' in CD but show preserved 'functional integrity'. Capillary rarefaction, an early risk factor of incipient vascular calcification, was strongly associated with biomarkers of altered mineral metabolism. Further studies are warranted to determine the impact of optimizing blood pressure and metabolic control on changes in capillary rarefaction in young CKD patients.
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Affiliation(s)
- Alcia Edwards-Richards
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Marissa DeFreitas
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Chryso P. Katsoufis
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Wacharee Seeherunvong
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Nao Sasaki
- Division of Pediatric Cardiology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Michael Freundlich
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Gaston Zilleruelo
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
| | - Carolyn L. Abitbol
- Division of Pediatric Nephrology, University of Miami/Holtz Children's Hospital, Miami, FL, USA
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Ergul A, Abdelsaid M, Fouda AY, Fagan SC. Cerebral neovascularization in diabetes: implications for stroke recovery and beyond. J Cereb Blood Flow Metab 2014; 34:553-63. [PMID: 24496174 PMCID: PMC3982092 DOI: 10.1038/jcbfm.2014.18] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/20/2013] [Accepted: 12/30/2013] [Indexed: 01/30/2023]
Abstract
Neovascularization is an innate physiologic response by which tissues respond to various stimuli through collateral remodeling (arteriogenesis) and new vessel formation from existing vessels (angiogenesis) or from endothelial progenitor cells (vasculogenesis). Diabetes has a major impact on the neovascularization process but the response varies between different organ systems. While excessive angiogenesis complicates diabetic retinopathy, impaired neovascularization contributes to coronary and peripheral complications of diabetes. How diabetes influences cerebral neovascularization remained unresolved until recently. Diabetes is also a major risk factor for stroke and poor recovery after stroke. In this review, we discuss the impact of diabetes, stroke, and diabetic stroke on cerebral neovascularization, explore potential mechanisms involved in diabetes-mediated neovascularization as well as the effects of the diabetic milieu on poststroke neovascularization and recovery, and finally discuss the clinical implications of these effects.
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Affiliation(s)
- Adviye Ergul
- 1] Charlie Norwood VA Medical Center, Augusta, Georgia, USA [2] Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA [3] Center for Pharmacy and Experimental Therapeutics, Medical College of Georgia and University of Georgia College of Pharmacy, Augusta, Georgia, USA
| | - Mohammed Abdelsaid
- 1] Charlie Norwood VA Medical Center, Augusta, Georgia, USA [2] Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA
| | - Abdelrahman Y Fouda
- 1] Charlie Norwood VA Medical Center, Augusta, Georgia, USA [2] Center for Pharmacy and Experimental Therapeutics, Medical College of Georgia and University of Georgia College of Pharmacy, Augusta, Georgia, USA
| | - Susan C Fagan
- 1] Charlie Norwood VA Medical Center, Augusta, Georgia, USA [2] Center for Pharmacy and Experimental Therapeutics, Medical College of Georgia and University of Georgia College of Pharmacy, Augusta, Georgia, USA [3] Department of Neurology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA
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76
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Kramann R, Tanaka M, Humphreys BD. Fluorescence microangiography for quantitative assessment of peritubular capillary changes after AKI in mice. J Am Soc Nephrol 2014; 25:1924-31. [PMID: 24652794 DOI: 10.1681/asn.2013101121] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
AKI predicts the future development of CKD, and one proposed mechanism for this epidemiologic link is loss of peritubular capillaries triggering chronic hypoxia. A precise definition of changes in peritubular perfusion would help test this hypothesis by more accurately correlating these changes with future loss of kidney function. Here, we have adapted and validated a fluorescence microangiography approach for use with mice to visualize, analyze, and quantitate peritubular capillary dynamics after AKI. A novel software-based approach enabled rapid and automated quantitation of capillary number, individual area, and perimeter. After validating perfusion in mice with genetically labeled endothelia, we compared peritubular capillary number and size after moderate AKI, characterized by complete renal recovery, and after severe AKI, characterized by development of interstitial fibrosis and CKD. Eight weeks after severe AKI, we measured a 40%±7.4% reduction in peritubular capillary number (P<0.05) and a 36%±4% decrease in individual capillary cross-sectional area (P<0.001) for a 62%±2.2% reduction in total peritubular perfusion (P<0.01). Whereas total peritubular perfusion and number of capillaries did not change, we detected a significant change of single capillary size following moderate AKI. The loss of peritubular capillary density and caliber at week 8 closely correlated with severity of kidney injury at day 1, suggesting irreparable microvascular damage. These findings emphasize a direct link between severity of acute injury and future loss of peritubular perfusion, demonstrate that reduced capillary caliber is an unappreciated long-term consequence of AKI, and offer a new quantitative imaging tool for understanding how AKI leads to future CKD in mouse models.
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Affiliation(s)
- Rafael Kramann
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany; and
| | - Mari Tanaka
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Benjamin D Humphreys
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Kidney Group, Harvard Stem Cell Institute, Cambridge, Massachussetts
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