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Local complement factor H protects kidney endothelial cell structure and function. Kidney Int 2021; 100:824-836. [PMID: 34139209 DOI: 10.1016/j.kint.2021.05.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 05/09/2021] [Accepted: 05/20/2021] [Indexed: 12/25/2022]
Abstract
Factor H (FH) is a critical regulator of the alternative complement pathway and its deficiency or mutation underlie kidney diseases such as dense deposit disease. Since vascular dysfunction is an important facet of kidney disease, maintaining optimal function of the lining endothelial cells is important for vascular health. To investigate the molecular mechanisms that are regulated by FH in endothelial cells, FH deficient and sufficient mouse kidney endothelial cell cultures were established. Endothelial FH deficiency resulted in cytoskeletal remodeling, increased angiogenic potential, loss of cellular layer integrity and increased cell proliferation. FH reconstitution prevented these FH-dependent proliferative changes. Respiratory flux analysis showed reduced basal mitochondrial respiration, ATP production and maximal respiratory capacity in FH deficient endothelial cells, while proton leak remained unaltered. Similar changes were observed in FH deficient human glomerular endothelial cells indicating the translational potential of these studies. Gene expression analysis revealed that the FH-dependent gene changes in mouse kidney endothelial cells include significant upregulation of genes involved in inflammation and the complement system. The transcription factor nuclear factor-kB, that regulates many biological processes, was translocated from the cytoplasm to the nucleus in the absence of FH. Thus, our studies show the functional relevance of intrinsic FH in kidney endothelial cells in man and mouse.
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Thorenz A, Derlin K, Schröder C, Dressler L, Vijayan V, Pradhan P, Immenschuh S, Jörns A, Echtermeyer F, Herzog C, Chen R, Rong S, Bräsen JH, van Kooten C, Kirsch T, Klemann C, Meier M, Klos A, Haller H, Hensen B, Gueler F. Enhanced activation of interleukin-10, heme oxygenase-1, and AKT in C5aR2-deficient mice is associated with protection from ischemia reperfusion injury-induced inflammation and fibrosis. Kidney Int 2018; 94:741-755. [PMID: 29935951 DOI: 10.1016/j.kint.2018.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 03/30/2018] [Accepted: 04/05/2018] [Indexed: 02/06/2023]
Abstract
Severe ischemia reperfusion injury (IRI) results in rapid complement activation, acute kidney injury and progressive renal fibrosis. Little is known about the roles of the C5aR1 and C5aR2 complement receptors in IRI. In this study C5aR1-/- and C5aR2-/- mice were compared to the wild type in a renal IRI model leading to renal fibrosis. C5a receptor expression, kidney morphology, inflammation, and fibrosis were measured in different mouse strains one, seven and 21 days after IRI. Renal perfusion was evaluated by functional magnetic resonance imaging. Protein abundance and phosphorylation were assessed with high content antibody microarrays and Western blotting. C5aR1 and C5aR2 were increased in damaged tubuli and even more in infiltrating leukocytes after IRI in kidneys of wild-type mice. C5aR1-/- and C5aR2-/- animals developed less IRI-induced inflammation and showed better renal perfusion than wild-type mice following IRI. C5aR2-/- mice, in particular, had enhanced tubular and capillary regeneration with less renal fibrosis. Anti-inflammatory IL-10 and the survival/growth kinase AKT levels were especially high in kidneys of C5aR2-/- mice following IRI. LPS caused bone marrow-derived macrophages from C5aR2-/- mice to release IL-10 and to express the stress response enzyme heme oxygenase-1. Thus, C5aR1 and C5aR2 have overlapping actions in which the kidneys of C5aR2-/- mice regenerate better than those in C5aR1-/- mice following IRI. This is mediated, at least in part, by differential production of IL-10, heme oxygenase-1 and AKT.
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Affiliation(s)
- Anja Thorenz
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Katja Derlin
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | | | | | - Vijith Vijayan
- Department of Transfusion Medicine, Hannover Medical School, Hannover, Germany
| | - Pooja Pradhan
- Department of Transfusion Medicine, Hannover Medical School, Hannover, Germany
| | - Stephan Immenschuh
- Department of Transfusion Medicine, Hannover Medical School, Hannover, Germany
| | - Anne Jörns
- Department of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Frank Echtermeyer
- Department of Anesthesiology and Intensive Care Medicine, Hannover Medical School, Hannover, Germany
| | - Christine Herzog
- Department of Anesthesiology and Intensive Care Medicine, Hannover Medical School, Hannover, Germany
| | - Rongjun Chen
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Song Rong
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | | | - Cees van Kooten
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - Torsten Kirsch
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Christian Klemann
- Department of Pediatric Surgery, Center of Surgery, Hannover Medical School, Hannover, Germany; Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Martin Meier
- Imaging Center of the Institute of Laboratory Animal Sciences, Hannover Medical School, Hannover, Germany
| | - Andreas Klos
- Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Hermann Haller
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Bennet Hensen
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Faikah Gueler
- Department of Nephrology, Hannover Medical School, Hannover, Germany.
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van Werkhoven MB, Damman J, Daha MR, Krikke C, van Goor H, van Son WJ, Hillebrands JL, van Dijk MC, Seelen MA. Novel insights in localization and expression levels of C5aR and C5L2 under native and post-transplant conditions in the kidney. Mol Immunol 2013; 53:237-45. [DOI: 10.1016/j.molimm.2012.08.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 10/27/2022]
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Ernandez T, Mayadas TN. Immunoregulatory role of TNFalpha in inflammatory kidney diseases. Kidney Int 2009; 76:262-76. [PMID: 19436333 DOI: 10.1038/ki.2009.142] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tumor necrosis factor alpha (TNFalpha), a pleiotropic cytokine, plays important inflammatory roles in renal diseases such as lupus nephritis, anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis and renal allograft rejection. However, TNFalpha also plays critical immunoregulatory roles that are required to maintain immune homeostasis. These complex biological functions of TNFalpha are orchestrated by its two receptors, TNFR1 and TNFR2. For example, TNFR2 promotes leukocyte infiltration and tissue injury in an animal model of immune complex-mediated glomerulonephritis. On the other hand, TNFR1 plays an immunoregulatory function in a murine lupus model with a deficiency in this receptor that leads to more severe autoimmune symptoms. In humans, proinflammatory and immunoregulatory roles for TNFalpha are strikingly illustrated in patients on anti-TNFalpha medications: These treatments are greatly beneficial in certain inflammatory diseases such as rheumatoid arthritis but, on the other hand, are also associated with the induction of autoimmune lupus-like syndromes and enhanced autoimmunity in multiple sclerosis patients. The indication for anti-TNFalpha treatments in renal inflammatory diseases is still under discussion. Ongoing clinical trials may help to clarify the potential benefit of such treatments in lupus nephritis and ANCA-associated glomerulonephritis. Overall, the complex biology of TNFalpha is not fully understood. A greater understanding of the function of its receptors may provide a framework to understand its contrasting proinflammatory and immunoregulatory functions. This may lead the development of new, more specific anti-inflammatory drugs.
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Affiliation(s)
- Thomas Ernandez
- Department of Pathology, Center for Excellence in Vascular Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Abstract
Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. Active and passive Heymann nephritis (HN) in rats are valuable experimental models because their features so closely resemble human MN. In HN, subepithelial immune deposits form in situ as a result of circulating antibodies. Complement activation leads to assembly of C5b-9 on glomerular epithelial cell (GEC) plasma membranes and is essential for sublethal GEC injury and the onset of proteinuria. This review revisits HN and focuses on areas of substantial progress in recent years. The response of the GEC to sublethal C5b-9 attack is not simply due to disruption of the plasma membrane but is due to the activation of specific signaling pathways. These include activation of protein kinases, phospholipases, cyclooxygenases, transcription factors, growth factors, NADPH oxidase, stress proteins, proteinases, and others. Ultimately, these signals impact on cell metabolic pathways and the structure/function of lipids and key proteins in the cytoskeleton and slit-diaphragm. Some signals affect GEC adversely. Thus C5b-9 induces partial dissolution of the actin cytoskeleton. There is a decline in nephrin expression, reduction in F-actin-bound nephrin, and loss of slit-diaphragm integrity. Other signals, such as endoplasmic reticulum stress, may limit complement-induced injury, or promote recovery. The extent of complement activation and GEC injury is dependent, in part, on complement-regulatory proteins, which act at early or late steps within the complement cascade. Identification of key steps in complement activation, the cellular signaling pathways, and the targets will facilitate therapeutic intervention in reversing GEC injury in human MN.
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Affiliation(s)
- Andrey V Cybulsky
- Renal Section, EBRC 504, Boston Univ. Medical Ctr., 650 Albany St., Boston, MA 02118, USA
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Loeffler DA. Using animal models to determine the significance of complement activation in Alzheimer's disease. J Neuroinflammation 2004; 1:18. [PMID: 15479474 PMCID: PMC529311 DOI: 10.1186/1742-2094-1-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Accepted: 10/12/2004] [Indexed: 12/11/2022] Open
Abstract
Complement inflammation is a major inflammatory mechanism whose function is to promote the removal of microorganisms and the processing of immune complexes. Numerous studies have provided evidence for an increase in this process in areas of pathology in the Alzheimer's disease (AD) brain. Because complement activation proteins have been demonstrated in vitro to exert both neuroprotective and neurotoxic effects, the significance of this process in the development and progression of AD is unclear. Studies in animal models of AD, in which brain complement activation can be experimentally altered, should be of value for clarifying this issue. However, surprisingly little is known about complement activation in the transgenic animal models that are popular for studying this disorder. An optimal animal model for studying the significance of complement activation on Alzheimer's – related neuropathology should have complete complement activation associated with senile plaques, neurofibrillary tangles (if present), and dystrophic neurites. Other desirable features include both classical and alternative pathway activation, increased neuronal synthesis of native complement proteins, and evidence for an increase in complement activation prior to the development of extensive pathology. In order to determine the suitability of different animal models for studying the role of complement activation in AD, the extent of complement activation and its association with neuropathology in these models must be understood.
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Affiliation(s)
- David A Loeffler
- Department of Neurology, William Beaumont Hospital Research Institute, Royal Oak, MI 48073, USA.
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