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Tang X, Dai H, Hu Y, Liu W, Zhao Q, Jiang H, Feng Z, Zhang N, Rui H, Liu B. Experimental models for elderly patients with membranous nephropathy: Application and advancements. Exp Gerontol 2024; 185:112341. [PMID: 38042380 DOI: 10.1016/j.exger.2023.112341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 12/04/2023]
Abstract
Membranous nephropathy (MN) occurs predominantly in middle-aged and elderly individuals and ranks among the most prevalent etiologies of elderly nephrotic syndrome. As an autoimmune glomerular disorder characterized by glomerular basement membrane thickening and immune complex deposition, conventional MN animal models, including the Heymann nephritis rat model and the c-BSA mouse model, have laid a foundation for MN pathogenesis research. However, differences in target antigens between rodents and humans have impeded this work. In recent years, researchers have created antigen-specific MN animal models, primarily centered on PLA2R1 and THSD7A, employing diverse techniques that provide innovative in vivo research platforms for MN. Furthermore, significant advancements have been made in the development of in vitro podocyte models relevant to MN. This review compiles recent antigen-specific MN animal models and podocyte models, elucidates their immune responses and pathological characteristics, and offers insights into the future of MN experimental model development. Our aim is to provide a comprehensive resource for research into the pathogenesis of MN and the development of targeted therapies for older patients with MN to prolong lifespan and improve quality of life.
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Affiliation(s)
- Xinyue Tang
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
| | - Haoran Dai
- Department of Nephrology, Shunyi Hospital, Beijing Traditional Chinese Medicine Hospital, Station East 5, Shunyi District, Beijing 101300, China
| | - Yuehong Hu
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
| | - Wenbin Liu
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, No. 11, North Third Ring Road, Chaoyang District, Beijing 100029, China
| | - Qihan Zhao
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
| | - Hanxue Jiang
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
| | - Zhendong Feng
- Pinggu Hospital, Beijing Hospital of Traditional Chinese Medicine, No. 6, Pingxiang Road, Pinggu District, Beijing 101200, China
| | - Naiqian Zhang
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China
| | - Hongliang Rui
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China; Beijing Institute of Chinese Medicine, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China.
| | - Baoli Liu
- Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Dongcheng District, Beijing 100010, China; Laboratory for Clinical Medicine, Capital Medical University, Beijing 100069, China.
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Nurcombe ZW, Hehr CL, McFarlane S. Plexina4 and cell survival in the developing zebrafish hindbrain. Dev Dyn 2023; 252:1323-1337. [PMID: 37283310 DOI: 10.1002/dvdy.633] [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: 11/20/2022] [Revised: 04/27/2023] [Accepted: 05/01/2023] [Indexed: 06/08/2023] Open
Abstract
BACKGROUND Growth factors are important in the developing and mature nervous system to support the survival of neurons. Developmental signaling molecules are known for their roles in controlling neurogenesis and neural circuit formation. Whether or not these molecules also have roles in cell survival in the developing nervous system is poorly understood. Plexins are a family of transmembrane receptors that bind Semaphorin ligands and are known to function in the guidance of developing axons and blood vessels. RESULTS In embryonic zebrafish, plexina4 is expressed widely in the brain, becoming largely restricted to the hindbrain as neurogenesis and differentiation proceed. Apoptosis is increased in the embryonic hindbrain of a plexina4ca307/ca307 CRISPR mutant. Based on the literature, we tested the secreted heat shock protein, Clusterin, as a candidate ligand to mediate cell survival through Plexina4. clusterin is expressed by the floor plate of the embryonic zebrafish hindbrain, in proximity to plexina4-expressing hindbrain cells. Morpholino-mediated knockdown of Clusterin increases cell apoptosis in the hindbrain, with additional cell death observed in epistasis experiments where Clusterin is knocked down in a plexina4 mutant background. CONCLUSIONS Our data suggest that Plexina4 promotes cell survival in the developing zebrafish hindbrain, likely through a pathway independent of Clusterin.
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Affiliation(s)
- Zachary W Nurcombe
- Department Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
- Graduate Program in Neuroscience, University of Calgary, Calgary, Alberta, Canada
| | - Carrie Lynn Hehr
- Department Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Sarah McFarlane
- Department Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
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Sang Y, Tsuji K, Nakanoh H, Fukushima K, Kitamura S, Wada J. Role of Semaphorin 3A in Kidney Development and Diseases. Diagnostics (Basel) 2023; 13:3038. [PMID: 37835781 PMCID: PMC10572269 DOI: 10.3390/diagnostics13193038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
Kidney diseases are worldwide public health problems affecting millions of people. However, there are still limited therapeutic options against kidney diseases. Semaphorin 3A (SEMA3A) is a secreted and membrane-associated protein, which regulates diverse functions, including immune regulation, cell survival, migration and angiogenesis, thus involving in the several pathogeneses of diseases, including eyes and neurons, as well as kidneys. SEMA3A is expressed in podocytes and tubular cells in the normal adult kidney, and recent evidence has revealed that excess SEMA3A expression and the subsequent signaling pathway aggravate kidney injury in a variety of kidney diseases, including nephrotic syndrome, diabetic nephropathy, acute kidney injury, and chronic kidney disease. In addition, several reports have demonstrated that the inhibition of SEMA3A ameliorated kidney injury via a reduction in cell apoptosis, fibrosis and inflammation; thus, SEMA3A may be a potential therapeutic target for kidney diseases. In this review article, we summarized the current knowledge regarding the role of SEMA3A in kidney pathophysiology and their potential use in kidney diseases.
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Affiliation(s)
- Yizhen Sang
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan; (Y.S.)
- Department of Rheumatology and Immunology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Kenji Tsuji
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan; (Y.S.)
| | - Hiroyuki Nakanoh
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan; (Y.S.)
| | - Kazuhiko Fukushima
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan; (Y.S.)
- Center for Systems Biology, Program in Membrane Biology, Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Shinji Kitamura
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan; (Y.S.)
- Department of Nursing Science, Faculty of Health and Welfare Science, Okayama Prefectural University, Okayama 719-1197, Japan
| | - Jun Wada
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan; (Y.S.)
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Caravaca-Fontán F, Yandian F, Fervenza FC. Future landscape for the management of membranous nephropathy. Clin Kidney J 2023; 16:1228-1238. [PMID: 37529655 PMCID: PMC10387398 DOI: 10.1093/ckj/sfad041] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Indexed: 08/03/2023] Open
Abstract
Among all glomerular diseases, membranous nephropathy (MN) is perhaps the one in which major progress has been made in recent decades, in both the understanding of the pathogenesis and treatment. Despite the overall significant response rates to these therapies-particularly rituximab and cyclical regimen based on corticosteroids and cyclophosphamide-cumulative experience over the years has shown, however, that 20%-30% of cases may confront resistant disease. Thus, these unmet challenges in the treatment of resistant forms of MN require newer approaches. Several emerging new agents-developed primarily for the treatment of hematological malignancies or rheumatoid diseases-are currently being evaluated in MN. Herein we conducted a narrative review on future therapeutic strategies in the disease. Among the different novel therapies, newer anti-CD20 agents (e.g. obinutuzumab), anti-CD38 (e.g. daratumumab, felzartamab), immunoadsorption or anti-complement therapies (e.g. iptacopan) have gained special attention. In addition, several technologies and innovations developed primarily for cancer (e.g. chimeric antigen receptor T-cell therapy, sweeping antibodies) seem particularly promising. In summary, the future therapeutic landscape in MN seems encouraging and will definitely move the management of this disease towards a more precision-based approach.
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Affiliation(s)
| | - Federico Yandian
- Department of Nephrology, Hospital de Clínicas “Dr Manuel Quintela”, Montevideo, Uruguay
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Kretschmer K, Stichel J, Bellmann-Sickert K, Baumann L, Bierer D, Riedl B, Beck-Sickinger AG. Pinpointing the interaction site between semaphorin-3A and its inhibitory peptide. J Pept Sci 2023; 29:e3460. [PMID: 36285908 DOI: 10.1002/psc.3460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/05/2022]
Abstract
Semaphorin-3A (Sema-3A) is a chemorepellant protein with various biological functions, including kidney development. It interacts with a protein complex consisting of the receptors neuropilin-1 (NRP-1) and plexin-A1. After acute kidney injury, Sema-3A is overexpressed and secreted, leading to a loss of kidney function. The development of peptide inhibitors is a promising approach to modulate the interaction of Sema-3A with its receptor NRP-1. Few interaction points between these binding partners are known. However, an immunoglobulin-like domain-derived peptide of Sema-3A has shown a positive effect on cell proliferation. To specify these interactions between the peptide inhibitor and the Sema-3A-NRP-1 system, the peptides were modified with the photoactivatable amino acids 4-benzoyl-l-phenylalanine or photo-l-leucine by solid-phase peptide synthesis. Activity was tested by an enzyme-linked immunosorbent-based binding assay, and crosslinking experiments were analyzed by Western blot and mass spectrometry, demonstrating a specific binding site of the peptide at Sema-3A. The observed signals for Sema-3A-peptide interaction were found in a defined area of the Sema domain, which was also demonstrated to be involved in NRP-1 binding. The presented data identified the interaction site for further development of therapeutic peptides to treat acute kidney injury by blocking the Sema-3A-NRP-1 interaction.
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Affiliation(s)
- Kevin Kretschmer
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Leipzig, Germany
| | - Jan Stichel
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Leipzig, Germany
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Tanaka Y, Yamamoto M, Nozu K, Hara S. An 8-month-old boy with infantile nephrotic syndrome caused by semaphorin 3B-associated membranous nephropathy. CEN Case Rep 2022:10.1007/s13730-022-00763-6. [PMID: 36504250 PMCID: PMC10393917 DOI: 10.1007/s13730-022-00763-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022] Open
Abstract
We present a case of nephrotic syndrome caused by semaphorin 3B-associated membranous nephropathy. The patient was an 8-month-old male infant who presented with severe proteinuria and hypertension. He was treated with prednisolone (PSL) for nephrotic syndrome; however, remission was not achieved within 4 weeks. He was diagnosed with steroid-resistant nephrotic syndrome and underwent kidney biopsy. Pathological examination revealed membranous nephropathy with IgG deposits on both the glomerular basement membrane (GBM) and the tubular basement membrane (TBM). He was treated with cyclosporine (CsA) in addition to PSL and achieved complete remission. However, frequent relapses occurred after the discontinuation or tapering of immunosuppressants. Two years after treatment initiation, a second biopsy was performed and showed worsening of the disease, which required treatment with several immunosuppressants to achieve complete remission. After that, we performed additional immunostaining for semaphorin 3B, which confirmed the diagnosis of semaphorin 3B-associated membranous nephropathy. Although extremely rare in infantile cases, semaphorin 3B-associated membranous nephropathy should be considered in the differential diagnosis, as strong treatment with immunosuppressants might be needed. In addition, mycophenolate mofetil showed an effective clinical response in this case, indicating that it can be considered for future treatment strategies.
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Chung EYM, Wang YM, Keung K, Hu M, McCarthy H, Wong G, Kairaitis L, Bose B, Harris DCH, Alexander SI. Membranous nephropathy: Clearer pathology and mechanisms identify potential strategies for treatment. Front Immunol 2022; 13:1036249. [PMID: 36405681 PMCID: PMC9667740 DOI: 10.3389/fimmu.2022.1036249] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/19/2022] [Indexed: 11/07/2022] Open
Abstract
Primary membranous nephropathy (PMN) is one of the common causes of adult-onset nephrotic syndrome and is characterized by autoantibodies against podocyte antigens causing in situ immune complex deposition. Much of our understanding of the disease mechanisms underpinning this kidney-limited autoimmune disease originally came from studies of Heymann nephritis, a rat model of PMN, where autoantibodies against megalin produced a similar disease phenotype though megalin is not implicated in human disease. In PMN, the major target antigen was identified to be M-type phospholipase A2 receptor 1 (PLA2R) in 2009. Further utilization of mass spectrometry on immunoprecipitated glomerular extracts and laser micro dissected glomeruli has allowed the rapid discovery of other antigens (thrombospondin type-1 domain-containing protein 7A, neural epidermal growth factor-like 1 protein, semaphorin 3B, protocadherin 7, high temperature requirement A serine peptidase 1, netrin G1) targeted by autoantibodies in PMN. Despite these major advances in our understanding of the pathophysiology of PMN, treatments remain non-specific, often ineffective, or toxic. In this review, we summarize our current understanding of the immune mechanisms driving PMN from animal models and clinical studies, and the implications on the development of future targeted therapeutic strategies.
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Affiliation(s)
- Edmund Y. M. Chung
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
| | - Yuan M. Wang
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
| | - Karen Keung
- Department of Nephrology, Prince of Wales Hospital, Randwick, NSW, Australia
| | - Min Hu
- The Centre for Transplant and Renal Research, Westmead Institute of Medical Research, Westmead, NSW, Australia
| | - Hugh McCarthy
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, Sydney Children’s Hospital, Randwick, NSW, Australia
| | - Germaine Wong
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, Westmead Hospital, Westmead, NSW, Australia
| | - Lukas Kairaitis
- Department of Nephrology, Blacktown Hospital, Blacktown, NSW, Australia
| | - Bhadran Bose
- Department of Nephrology, Nepean Hospital, Kingswood, NSW, Australia
| | - David C. H. Harris
- The Centre for Transplant and Renal Research, Westmead Institute of Medical Research, Westmead, NSW, Australia
- Department of Nephrology, Westmead Hospital, Westmead, NSW, Australia
| | - Stephen I. Alexander
- Centre for Kidney Research, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Department of Nephrology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
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8
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Huang G, Liu F, Yu L, Wang J, Chen J, Mao J. Pediatric membranous nephropathy: In the novel antigens era. Front Immunol 2022; 13:962502. [PMID: 36016931 PMCID: PMC9396344 DOI: 10.3389/fimmu.2022.962502] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/21/2022] [Indexed: 01/10/2023] Open
Abstract
Membranous nephropathy (MN) falls within the scope of a glomerular disease. MN exhibits subepithelial immune- complex deposition and capillary wall thickening which could occur in all age groups. In comparison with adult patients with MN, MN in pediatric population has a lower incidence and more secondary factors (e.g., systemic lupus erythematosus, infection, malignancy, or drug toxicity). Two target antigens for the immune complexes, PLA2R (identified in 2009) and THSD7A (in 2014), found in previous studies and first presented in adult MN, are found in pediatric patients suffering from MN and their antibodies are now an effective tool for diagnosis and monitoring in children and adolescents. Several novel antigens have been identified (e.g., EXT1/EXT2, NELL1, Sema3B, PCDH7, HTRA1, and NCAM1) over the past few years. Each of them represents different clinical and pathologic findings. In-depth research should be conducted to gain insights into the outcomes and pathophysiology of the above novel antigen-associated MN. Targeted treatment opinions for different novel antigen-related MN are under development both in adults and pediatric patients.
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Salvadori M, Tsalouchos A. New antigens involved in membranous nephropathy beyond phospholipase A2 receptor. World J Nephrol 2022; 11:115-126. [PMID: 36161266 PMCID: PMC9353762 DOI: 10.5527/wjn.v11.i4.115] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/24/2022] [Accepted: 07/11/2022] [Indexed: 02/06/2023] Open
Abstract
When the physiopathology of membranous nephropathy was first described, almost 30% of cases were recognized to be secondary to well-known diseases such as autoimmune diseases, tumors or infections. The remaining 70% cases were called primary membranous nephropathy as the exact mechanism or pathogenic factor involved was unknown. The discovery of the M type phospholipase A2 receptor and thrombospondin type 1 domain containing 7A as causative antigens in these “so called” primary membranous nephropathies provided new insights into the effective causes of a large proportion of these cases. Novel techniques such as laser microdissection and tandem mass spectrometry as well as immunochemistry with antibodies directed against novel proteins allowed the confirmation of new involved antigens. Finally, using confocal microscopy to localize these new antigens and immunoglobulin G and Western blot analysis of serum samples, these new antigens were detected on the glomerular membrane, and the related antibodies were detected in serum samples. The same antigens have been recognized in some cases of secondary membranous disease due to autoimmune diseases, tumors and infections. This has allowed examination of the relationship between antigens in primary membranous nephropathy and their presence in some secondary nephropathies. The aim of this study is to describe the characteristics of the new antigens discovered and their association with other diseases.
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Affiliation(s)
- Maurizio Salvadori
- Department of Renal Transplantation, Careggi University Hospital, Florence 50139, Tuscany, Italy
| | - Aris Tsalouchos
- Division of Nephrology, Santa Maria Annunziata, Florence 50012, Tuscany, Italy
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Caravaca-Fontán F, Fernandez-Juarez GM, Floege J, Goumenos D, Kronbichler A, Turkmen K, van Kooten C, Frangou E, Stevens KI, Segelmark M, Tesar V, Anders HJ, Bruchfeld A. The management of membranous nephropathy - an update. Nephrol Dial Transplant 2021; 37:1033-1042. [PMID: 34748001 DOI: 10.1093/ndt/gfab316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Indexed: 11/13/2022] Open
Abstract
In the last decades several important advances have taken place in the understanding of the pathogenesis underlying membranous nephropathy, which have sparked renewed interest in its management. Four landmark trials in membranous nephropathy, and a fifth clinical trial-which was a pilot study-, have been published in the last years. The results from some of these trials have had a significant impact in the recommendations included in the 2021 Kidney Disease: Improving Global Outcomes (KDIGO) Guideline for the Management of Glomerular Diseases, which represent a significant step forward compared to the previous guideline in several aspects such as diagnosis, disease monitoring and treatment strategies. However, considering the rapidly evolving advances in the knowledge of membranous nephropathy and the recent publication of the STARMEN and RI-CYCLO trials, several recommendations contained in the guideline warrant updates. This manuscript provides a perspective of the Immunonephrology Working Group of the European Renal Association (ERA) regarding the management of membranous nephropathy in native kidneys of adult patients.
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Affiliation(s)
| | | | - Jürgen Floege
- Division of Nephrology, RWTH Aachen University Hospital, Aachen, Germany
| | - Dimitrios Goumenos
- Department of Nephrology and Renal Transplantation, Patras University Hospital, Patras, Greece
| | | | - Kultigin Turkmen
- Division of Nephrology, Department of Internal Medicine, Necmettin Erbakan University, Konya, Turkey
| | - Cees van Kooten
- Division of Nephrology and Transplant Medicine, Department of Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Eleni Frangou
- Department of Nephrology and Transplantation, Nicosia General Hospital, Nicosia, Cyprus. Medical School, University of Cyprus, Nicosia, Cyprus
| | - Kate I Stevens
- Department of Nephrology and Transplantation, Queen Elizabeth University Hospital, Glasgow, United Kingdom
| | - Mårten Segelmark
- Division of Nephrology, Department of Clinical Sciences Lund, Lund University and Skane University Hospital, Lund, Sweden.,Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Vladimir Tesar
- Department of Nephrology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Hans-Joachim Anders
- Department of Internal Medicine IV, Hospital of the Ludwig Maximilians University, Munich, Germany
| | - Annette Bruchfeld
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Department of Renal Medicine, Karolinska University Hospital and CLINTEC Karolinska Institutet, Stockholm, Sweden
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11
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Sang Y, Tsuji K, Fukushima K, Takahashi K, Kitamura S, Wada J. Semaporin3A-inhibitor ameliorates renal fibrosis through the regulation of JNK signaling. Am J Physiol Renal Physiol 2021; 321:F740-F756. [PMID: 34747196 DOI: 10.1152/ajprenal.00234.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Renal fibrosis is the common pathological pathway in progressive renal diseases. In the study, we analyzed the roles of Semaphorin 3A (SEMA3A) on renal fibrosis and the effect of SEMA3A-inhibitor (SEMA3A-I) using unilateral ureteral obstruction (UUO) mouse model. The expression of SEMA3A in the proximal tubulus and neuropilin-1 (NRP1), a recepor of SEMA3A, in fibloblast and tubular cells were increased in the UUO kidneys. The increased expression of myofibroblast marker tenascin-C and fibronection as well as renal fibrosis were increased in UUO kidneys, all of which were ameliorated by SEMA3A-I. In addition, c-Jun N-terminal kinase (JNK) signaling pathway known as the target of SEMA3A signaling, was activated in proximal tubular cells and fibroblast cells after UUO surgery while SEMA3A-I significantly attenuated the activation. In vitro, treatments with SEMA3A as well as transforming growth factor-β1 (TGF-β1) in human proximal tubular cells lost epithelial cell characters while SEMA3A-I significantly ameliorated this transformation. JNK inhibitor, SP600125, partially reversed SEMA3A and TGF-β1-induced cell transformation, indicating that JNK signaling is involved in SEMA3A-induced renal fibrosis. In addition, the treatment with SEMA3A in fibroblast cells activated the expression of tenascin-C, collagen type I and fibronection, indicating that SEMA3A may accelerate renal fibrosis through the activation of fibroblast cells. The analysis of human data revealed the positive correlation between urinary SEMA3A and urinary N-acetyl-β-D-glucosaminidase, indicating the association between SEMA3A and tubular injury. In conclusion, SEMA3A signaling is involved in renal fibrosis through JNK signaling pathway and SEMA3A-I might be the therapeutic option for protecting from renal fibrosis.
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Affiliation(s)
- Yizhen Sang
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University, Okayama, Japan
| | - Kenji Tsuji
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University, Okayama, Japan
| | - Kazuhiko Fukushima
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University, Okayama, Japan
| | - Kensaku Takahashi
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University, Okayama, Japan
| | - Shinji Kitamura
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University, Okayama, Japan
| | - Jun Wada
- Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University, Okayama, Japan
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12
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Liu W, Huang G, Rui H, Geng J, Hu H, Huang Y, Huo G, Liu B, Xu A. Course monitoring of membranous nephropathy: Both autoantibodies and podocytes require multidimensional attention. Autoimmun Rev 2021; 21:102976. [PMID: 34757091 DOI: 10.1016/j.autrev.2021.102976] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/18/2021] [Accepted: 10/24/2021] [Indexed: 01/15/2023]
Abstract
A variety of podocyte antigens have been identified in human membranous nephropathy (MN), which is divided into various antigen-dominated subtypes, confirming the concept that MN is the common pattern of glomerular injury in multiple autoimmune responses. The detection of autoantibodies has been widely used, which promoted the clinical practice of MN toward personalized precision medicine. However, given the potential risks of immunosuppressive therapy, more autoantibodies and biomarkers need to be identified to predict the prognosis and therapeutic response of MN more accurately. In this review, we attempted to summarize the autoantigens/autoantibodies and autoimmune mechanisms that can predict disease states based on the current understanding of MN pathogenesis, especially the podocyte injury manifestations. In conclusion, both the autoimmune response and podocyte injury require multidimensional attention in the disease course of MN.
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Affiliation(s)
- Wenbin Liu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Guangrui Huang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Hongliang Rui
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Jie Geng
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Haikun Hu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Yujiao Huang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Guiyang Huo
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Baoli Liu
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China.
| | - Anlong Xu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China.
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13
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Low Urine Secretion of Semaphorin3A in Lupus Patients with Proteinuria. Inflammation 2021; 45:603-609. [PMID: 34562225 DOI: 10.1007/s10753-021-01570-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 10/20/2022]
Abstract
Immune semaphorins are important in controlling both innate and adaptive immune responses. The regulatory role of semaphorin3A (sema3A) in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and other autoimmune diseases is widely reported. Decreased levels of serum sema3A were shown to correlate with SLE disease activity. The aim was to assess urine concentrations of sema3A in SLE patients and its correlation with renal involvement and disease activity. Urine levels of sema3A were analyzed in 38 SLE patients, 13 with renal involvement, and were compared to 10 healthy volunteers and 8 RA patients (disease control group). The excretion of urine sema3A was found to be significantly lower in SLE patients compared to healthy volunteers and RA patients (4.9 ± 3.9 ng/ml, 8.5 ± 2.7 ng/ml, 9.85 ± 1.7 ng/ml, respectively, p = 0.0006). Urine sema3A was significantly lower in SLE patients with lupus nephritis than in patients without nephritis (4.0 ± 3.4 ng/ml vs. 6.5 ± 3.8 ng/ml, p = 0.03). Urine sema3A inversely correlated with proteinuria and SLE disease activity. Urine sema3A is decreased in lupus patients and should be further evaluated as a possible biomarker for disease activity and renal involvement.
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Róka B, Tod P, Kaucsár T, Bukosza ÉN, Vörös I, Varga ZV, Petrovich B, Ágg B, Ferdinandy P, Szénási G, Hamar P. Delayed Contralateral Nephrectomy Halted Post-Ischemic Renal Fibrosis Progression and Inhibited the Ischemia-Induced Fibromir Upregulation in Mice. Biomedicines 2021; 9:biomedicines9070815. [PMID: 34356879 PMCID: PMC8301422 DOI: 10.3390/biomedicines9070815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 12/12/2022] Open
Abstract
(1) Background: Ischemia reperfusion (IR) is the leading cause of acute kidney injury (AKI) and results in predisposition to chronic kidney disease. We demonstrated that delayed contralateral nephrectomy (Nx) greatly improved the function of the IR-injured kidney and decelerated fibrosis progression. Our aim was to identify microRNAs (miRNA/miR) involved in this process. (2) Methods: NMRI mice were subjected to 30 min of renal IR and one week later to Nx/sham surgery. The experiments were conducted for 7-28 days after IR. On day 8, multiplex renal miRNA profiling was performed. Expression of nine miRNAs was determined with qPCR at all time points. Based on the target prediction, plexin-A2 and Cd2AP were measured by Western blot. (3) Results: On day 8 after IR, the expression of 20/1195 miRNAs doubled, and 9/13 selected miRNAs were upregulated at all time points. Nx reduced the expression of several ischemia-induced pro-fibrotic miRNAs (fibromirs), such as miR-142a-duplex, miR-146a-5p, miR-199a-duplex, miR-214-3p and miR-223-3p, in the injured kidneys at various time points. Plexin-A2 was upregulated by IR on day 10, while Cd2AP was unchanged. (4) Conclusion: Nx delayed fibrosis progression and decreased the expression of ischemia-induced fibromirs. The protein expression of plexin-A2 and Cd2AP is mainly regulated by factors other than miRNAs.
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Affiliation(s)
- Beáta Róka
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (B.R.); (P.T.); (T.K.); (É.N.B.); (G.S.)
| | - Pál Tod
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (B.R.); (P.T.); (T.K.); (É.N.B.); (G.S.)
- Institute for Translational Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Tamás Kaucsár
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (B.R.); (P.T.); (T.K.); (É.N.B.); (G.S.)
| | - Éva Nóra Bukosza
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (B.R.); (P.T.); (T.K.); (É.N.B.); (G.S.)
| | - Imre Vörös
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089 Budapest, Hungary; (I.V.); (Z.V.V.); (B.P.); (B.Á.); (P.F.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, 1089 Budapest, Hungary
| | - Zoltán V. Varga
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089 Budapest, Hungary; (I.V.); (Z.V.V.); (B.P.); (B.Á.); (P.F.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, 1089 Budapest, Hungary
| | - Balázs Petrovich
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089 Budapest, Hungary; (I.V.); (Z.V.V.); (B.P.); (B.Á.); (P.F.)
| | - Bence Ágg
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089 Budapest, Hungary; (I.V.); (Z.V.V.); (B.P.); (B.Á.); (P.F.)
- Pharmahungary Group, 6722 Szeged, Hungary
| | - Péter Ferdinandy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089 Budapest, Hungary; (I.V.); (Z.V.V.); (B.P.); (B.Á.); (P.F.)
- Pharmahungary Group, 6722 Szeged, Hungary
| | - Gábor Szénási
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (B.R.); (P.T.); (T.K.); (É.N.B.); (G.S.)
| | - Péter Hamar
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (B.R.); (P.T.); (T.K.); (É.N.B.); (G.S.)
- Institute for Translational Medicine, Medical School, University of Pécs, 7624 Pécs, Hungary
- Correspondence: ; Tel.: +36-20-825-9751
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15
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Ronco P, Debiec H. Membranous nephropathy: current understanding of various causes in light of new target antigens. Curr Opin Nephrol Hypertens 2021; 30:287-293. [PMID: 33480620 PMCID: PMC8048721 DOI: 10.1097/mnh.0000000000000697] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Membranous nephropathy is an autoimmune disease caused by antibodies mostly directed to podocyte antigens. PLA2R and THSD7A antigens were described in 2009 and 2014 using classical immunochemical techniques. In the last 2 years, thanks to the combination of laser microdissection of glomeruli and mass spectrometry of solubilized digested proteins, several antigens associated with various causes have been described in patients with membranous nephropathy. The purpose of this review is to report on those "new" antigens and to analyse the clinicopathological correlations that make each of this antigen unique. RECENT FINDINGS This article covers the literature of the last 2 years devoted to the description of those new antigens and biomarkers including NELL-1 and Semaphorin 3B in primary membranous nephropathy, and exostosins 1 and 2 and NCAM in lupus class V membranous nephropathy, which will be compared with the previously described antigens. These findings will lead to propose a new classification of membranous nephropathy based on serology and tissue antigen identification that could/should substitute for the classical distinction between primary and secondary membranous nephropathy. SUMMARY The discovery of the latest antigens has major implications for the care of patients with membranous nephropathy as they drive the etiologic investigations and provide invaluable markers for treatment monitoring.
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Affiliation(s)
- Pierre Ronco
- Sorbonne Université, Université Pierre et Marie Curie Paris 06, and Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S1155, Paris
- Centre Hospitalier du Mans, Department of Nephrology, Le Mans, France
| | - Hanna Debiec
- Sorbonne Université, Université Pierre et Marie Curie Paris 06, and Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S1155, Paris
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16
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Mechanisms of Primary Membranous Nephropathy. Biomolecules 2021; 11:biom11040513. [PMID: 33808418 PMCID: PMC8065962 DOI: 10.3390/biom11040513] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 12/11/2022] Open
Abstract
Membranous nephropathy (MN) is an autoimmune disease of the kidney glomerulus and one of the leading causes of nephrotic syndrome. The disease exhibits heterogenous outcomes with approximately 30% of cases progressing to end-stage renal disease. The clinical management of MN has steadily advanced owing to the identification of autoantibodies to the phospholipase A2 receptor (PLA2R) in 2009 and thrombospondin domain-containing 7A (THSD7A) in 2014 on the podocyte surface. Approximately 50–80% and 3–5% of primary MN (PMN) cases are associated with either anti-PLA2R or anti-THSD7A antibodies, respectively. The presence of these autoantibodies is used for MN diagnosis; antibody levels correlate with disease severity and possess significant biomarker values in monitoring disease progression and treatment response. Importantly, both autoantibodies are causative to MN. Additionally, evidence is emerging that NELL-1 is associated with 5–10% of PMN cases that are PLA2R- and THSD7A-negative, which moves us one step closer to mapping out the full spectrum of PMN antigens. Recent developments suggest exostosin 1 (EXT1), EXT2, NELL-1, and contactin 1 (CNTN1) are associated with MN. Genetic factors and other mechanisms are in place to regulate these factors and may contribute to MN pathogenesis. This review will discuss recent developments over the past 5 years.
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17
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Liu J, Zhao Y, Li ZQ, Chen Q, Luo CQ, Su JX, Wang YM. Biomarkers for detecting and improving AKI after liver transplantation: From diagnosis to treatment. Transplant Rev (Orlando) 2021; 35:100612. [PMID: 33721594 DOI: 10.1016/j.trre.2021.100612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/25/2021] [Accepted: 02/27/2021] [Indexed: 11/18/2022]
Abstract
Orthotopic liver transplantation (OLT) is a well-established treatment for patients with liver failure. The shortage of donor organs and postoperative complications remain major obstacles for improving patient survival. Among these complications, acute kidney injury (AKI) is one of the most frequent types, contributing to graft loss. The timely detection and reversal of AKI can reduce its adverse influences on graft and patient outcomes. Traditional markers for detecting AKI are often limited with regard to their accuracy and specificity, and the discovery of better AKI markers and therapeutic targets assumes great importance. During past decades, studies directed toward early detection and treatment of AKI in OLT have been available. This review summarizes the evidence of these biomarkers for the prediction, diagnosis, treatment and prognosis stratification of AKI associated with OLT.
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Affiliation(s)
- Jing Liu
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yi Zhao
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zhen-Qiong Li
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Qing Chen
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Chang-Qing Luo
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jin-Xuan Su
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yu-Mei Wang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
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18
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Ronco P, Plaisier E, Debiec H. Advances in Membranous Nephropathy. J Clin Med 2021; 10:607. [PMID: 33562791 PMCID: PMC7915386 DOI: 10.3390/jcm10040607] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 12/12/2022] Open
Abstract
Membranous nephropathy (MN) is a rare auto-immune disease where the glomerulus is targeted by circulating auto-antibodies mostly against podocyte antigens, which results in the formation of electron-dense immune complexes, activation of complement and massive proteinuria. MN is the most common cause of nephrotic syndrome in adults leading to severe thrombotic complications and kidney failure. This review is focused on the recent therapeutic and pathophysiological advances that occurred in the last two years. For a long time, we were lacking a head-to-head comparison between cyclophosphamide considered as the gold standard therapy and other medications, notably rituximab. Substantial progress has been achieved owing to three randomized controlled trials. MENTOR (Membranous Nephropathy Trial of Rituximab) and STARMEN (Sequential Therapy with Tacrolimus and Rituximab in Primary Membranous Nephropathy) conclusively established that calcineurin inhibitor-based regimens are slower to result in an immunologic response than rituximab or cyclophosphamide, achieve fewer complete clinical remissions, and are less likely to maintainremission. Rituximab Versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO) suggested that competition between cyclophosphamide and rituximab remains open. Given the technological leap combining laser microdissection of glomeruli and mass spectrometry of solubilized digested proteins, four "new antigens" were discovered including NELL-1 and Semaphorin 3B in so-called primary MN, and exostosins 1 and 2 and NCAM 1 in lupus MN. NELL-1 is associated with about 8% of primary MN and is characterized by segmental immune deposits and frequent association with cancer (30%). Semaphorin 3B-associated MN usually occurs in children, often below the age of two years, where it is the main antigen, representing about 16% of non-lupus MN in childhood. Exostosins 1/2 and NCAM 1 are associated with 30% and 6% of lupus MN, respectively. Exostosins 1/2 (EXT1/2) staining is associated with a low rate of end-stage kidney disease (ESKD) even in mixed classes III/IV+V. These findings already lead to revisiting the diagnostic and therapeutic algorithms toward more personalized medicine.
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Affiliation(s)
- Pierre Ronco
- Unité Mixte de Recherche S1155, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université Pierre et Marie Curie Paris 06, Hôpital Tenon, 75020 Paris, France; (E.P.); (H.D.)
- Reference Center of Rare Disease-Idiopathic Nephrotic Syndrome, Hôpital Tenon, 75020 Paris, France
- Department of Nephrology, Centre Hospitalier du Mans, 72000 Le Mans, France
| | - Emmanuelle Plaisier
- Unité Mixte de Recherche S1155, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université Pierre et Marie Curie Paris 06, Hôpital Tenon, 75020 Paris, France; (E.P.); (H.D.)
- Reference Center of Rare Disease-Idiopathic Nephrotic Syndrome, Hôpital Tenon, 75020 Paris, France
- Day Hospital of Nephrology, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, 75020 Paris, France
| | - Hanna Debiec
- Unité Mixte de Recherche S1155, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université Pierre et Marie Curie Paris 06, Hôpital Tenon, 75020 Paris, France; (E.P.); (H.D.)
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19
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Abstract
Membranous nephropathy (MN) occurs due to deposition of immune complexes along the subepithelial region of glomerular basement membrane. Two previously identified target antigens for the immune complexes, PLA2R (identified in 2009) and THSD7A (in 2014), account for approximately 60% of all MN, both primary and secondary. In the remaining MN, target antigens were unknown. Use of laser microdissection and mass spectrometry enabled identification of new "antigens." This approach led to the identification of four novel types of MN: exotosin 1 (EXT1)- and exotosin 2 (EXT2)-associated MN, NELL1-associated MN, Sema3B-associated MN, and PCDH7-associated MN. Each of these represents a distinct disease entity, with different clinical and pathologic findings. In this review, the structure of the proteins and the clinical and pathologic findings of the new types of MN are discussed. The role of mass spectrometry for accurate diagnosis of MN cannot be overemphasized. Finally, any classification of MN should be made on the basis of the antigens that are detected. Further studies are required to understand the pathophysiology, response to treatment, and outcomes of these new MNs.
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Affiliation(s)
- Sanjeev Sethi
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
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20
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Semaphorin 3B-associated membranous nephropathy is a distinct type of disease predominantly present in pediatric patients. Kidney Int 2020; 98:1253-1264. [PMID: 32534052 DOI: 10.1016/j.kint.2020.05.030] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 05/01/2020] [Accepted: 05/07/2020] [Indexed: 12/15/2022]
Abstract
Membranous nephropathy results from subepithelial antigen-antibody complex deposition along the glomerular basement membrane. Although PLA2R, THSD7A, and NELL-1 account for a majority (about 80%) of the target antigens, the target antigen in the remaining cases is not known. Using laser microdissection of PLA2R-negative glomeruli of patients with membranous nephropathy followed by mass spectrometry we identified a unique protein, Semaphorin 3B, in three cases. Mass spectrometry failed to detect Semaphorin-3B in 23 PLA2R-associated cases of membranous nephropathy and 88 controls. Semaphorin 3B in all three cases was localized to granular deposits along the glomerular basement membrane by immunohistochemistry. Next, an additional eight cases of Semaphorin 3B-associated membranous nephropathy were identified in three validation cohorts by immunofluorescence microscopy. In four of 11 cases, kidney biopsy also showed tubular basement membrane deposits of IgG on frozen sections. Confocal microscopy showed that both IgG and Semaphorin 3B co-localized to the glomerular basement membrane. Western blot analysis of five available sera showed reactivity to reduced Semaphorin 3B in four of four patients with active disease and no reactivity in one patient in clinical remission; there was also no reactivity in control sera. Eight of the 11 cases of Semaphorin 3B-associated membranous nephropathy were pediatric cases. Furthermore, in five cases, the disease started at or below the age of two. Thus, Semaphorin 3B-associated membranous nephropathy appears to be a distinct type of disease; more likely to be present in pediatric patients.
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21
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Sang Y, Tsuji K, Inoue-Torii A, Fukushima K, Kitamura S, Wada J. Semaphorin3A-Inhibitor Ameliorates Doxorubicin-Induced Podocyte Injury. Int J Mol Sci 2020; 21:ijms21114099. [PMID: 32521824 PMCID: PMC7312798 DOI: 10.3390/ijms21114099] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 05/30/2020] [Accepted: 06/05/2020] [Indexed: 12/16/2022] Open
Abstract
Podocyte injury is an independent risk factor for the progression of renal diseases. Semaphorin3A (SEMA3A), expressed in podocytes and tubular cells in the mammalian adult kidneys, has been reported to regulate diverse biological functions and be associated with renal diseases. Here, we investigated pathological roles of SEMA3A signaling on podocyte injury using a doxorubicin (Dox)-induced mouse model and examined the therapeutic effect of SEMA3A-inhibitor (SEMA3A-I). We demonstrated that Dox caused massive albuminuria and podocyte apoptosis as well as an increase of SEMA3A expression in podocytes, all of which were ameliorated with SEMA3A-I treatment. In addition, c-Jun N-terminal kinase (JNK), known as a downstream of SEMA3A signaling, was activated in Dox-injected mouse podocytes while SEMA3A-I treatment partially blocked the activation. In vitro, SEMA3A-I protected against Dox-induced podocyte apoptosis and recombinant SEMA3A caused podocyte apoptosis with activation of JNK signaling. JNK inhibitor, SP600125, attenuated SEMA3A-induced podocyte apoptosis, indicating that the JNK pathway would be involved in SEMA3A-induced podocyte apoptosis. Furthermore, the analysis of human data revealed a positive correlation between levels of urinary SEMA3A and protein, suggesting that SEMA3A is associated with podocyte injury. In conclusion, SEMA3A has essential roles in podocyte injury and it would be the therapeutic target for protecting from podocyte injury.
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Affiliation(s)
| | | | | | | | - Shinji Kitamura
- Correspondence: ; Tel.: +81-86-235-7235; Fax: +81-86-222-5214
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22
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Sema 3A as a biomarker of the activated mTOR pathway during hexavalent chromium-induced acute kidney injury. Toxicol Lett 2018; 299:226-235. [DOI: 10.1016/j.toxlet.2018.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 09/09/2018] [Accepted: 09/16/2018] [Indexed: 12/13/2022]
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23
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Zhang M, Zhou Q, Luo Y, Nguyen T, Rosenblatt MI, Guaiquil VH. Semaphorin3A induces nerve regeneration in the adult cornea-a switch from its repulsive role in development. PLoS One 2018; 13:e0191962. [PMID: 29370308 PMCID: PMC5785010 DOI: 10.1371/journal.pone.0191962] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 01/15/2018] [Indexed: 12/25/2022] Open
Abstract
The peripheral sensory nerves that innervate the cornea can be easily damaged by trauma, surgery, infection or diabetes. Several growth factors and axon guidance molecules, such as Semaphorin3A (Sema3A) are upregulated upon cornea injury. Nerves can regenerate after injury but do not recover their original density and patterning. Sema3A is a well known axon guidance and growth cone repellent protein during development, however its role in adult cornea nerve regeneration remains undetermined. Here we investigated the neuro-regenerative potential of Sema3A on adult peripheral nervous system neurons such as those that innervate the cornea. First, we examined the gene expression profile of the Semaphorin class 3 family members and found that all are expressed in the cornea. However, upon cornea injury there is a fast increase in Sema3A expression. We then corroborated that Sema3A totally abolished the growth promoting effect of nerve growth factor (NGF) on embryonic neurons and observed signs of growth cone collapse and axonal retraction after 30 min of Sema3A addition. However, in adult isolated trigeminal ganglia or dorsal root ganglia neurons, Sema3A did not inhibited the NGF-induced neuronal growth. Furthermore, adult neurons treated with Sema3A alone produced similar neuronal growth to cells treated with NGF and the length of the neurites and branching was comparable between both treatments. These effects were replicated in vivo, where thy1-YFP neurofluorescent mice subjected to cornea epithelium debridement and receiving intrastromal pellet implantation containing Sema3A showed increased corneal nerve regeneration than those receiving pellets with vehicle. In adult PNS neurons, Sema3A is a potent inducer of neuronal growth in vitro and cornea nerve regeneration in vivo. Our data indicates a functional switch for the role of Sema3A in PNS neurons where the well-described repulsive role during development changes to a growth promoting effect during adulthood. The high expression of Sema3A in the normal and injured adult corneas could be related to its role as a growth factor.
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Affiliation(s)
- Min Zhang
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Qiang Zhou
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Yuncin Luo
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Tara Nguyen
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Mark I. Rosenblatt
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Victor H. Guaiquil
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
- * E-mail:
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24
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Naudin C, Smith B, Bond DR, Dun MD, Scott RJ, Ashman LK, Weidenhofer J, Roselli S. Characterization of the early molecular changes in the glomeruli of Cd151 -/- mice highlights induction of mindin and MMP-10. Sci Rep 2017; 7:15987. [PMID: 29167507 PMCID: PMC5700190 DOI: 10.1038/s41598-017-15993-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/26/2017] [Indexed: 01/06/2023] Open
Abstract
In humans and FVB/N mice, loss of functional tetraspanin CD151 is associated with glomerular disease characterised by early onset proteinuria and ultrastructural thickening and splitting of the glomerular basement membrane (GBM). To gain insight into the molecular mechanisms associated with disease development, we characterised the glomerular gene expression profile at an early stage of disease progression in FVB/N Cd151 -/- mice compared to Cd151 +/+ controls. This study identified 72 up-regulated and 183 down-regulated genes in FVB/N Cd151 -/- compared to Cd151 +/+ glomeruli (p < 0.05). Further analysis highlighted induction of the matrix metalloprotease MMP-10 and the extracellular matrix protein mindin (encoded by Spon2) in the diseased FVB/N Cd151 -/- GBM that did not occur in the C57BL/6 diseased-resistant strain. Interestingly, mindin was also detected in urinary samples of FVB/N Cd151 -/- mice, underlining its potential value as a biomarker for glomerular diseases associated with GBM alterations. Gene set enrichment and pathway analysis of the microarray dataset showed enrichment in axon guidance and actin cytoskeleton signalling pathways as well as activation of inflammatory pathways. Given the known function of mindin, its early expression in the diseased GBM could represent a trigger of both further podocyte cytoskeletal changes and inflammation, thereby playing a key role in the mechanisms of disease progression.
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Affiliation(s)
- Crystal Naudin
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.,Hunter Medical Research Institute, New Lambton, New South Wales, Australia.,Emory University, Atlanta, Georgia, USA
| | - Brian Smith
- School of Mathematics and Physical Sciences, University of Newcastle, Newcastle, New South Wales, Australia
| | - Danielle R Bond
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.,Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Matthew D Dun
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.,Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Rodney J Scott
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.,Hunter Medical Research Institute, New Lambton, New South Wales, Australia.,Hunter Area Pathology Service, John Hunter Hospital, New Lambton, New South Wales, Australia
| | - Leonie K Ashman
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.,Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Judith Weidenhofer
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.,Hunter Medical Research Institute, New Lambton, New South Wales, Australia
| | - Séverine Roselli
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia. .,Hunter Medical Research Institute, New Lambton, New South Wales, Australia.
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Inoue-Torii A, Kitamura S, Wada J, Tsuji K, Makino H. The level of urinary semaphorin3A is associated with disease activity in patients with minimal change nephrotic syndrome. Int J Nephrol Renovasc Dis 2017; 10:167-174. [PMID: 28790860 PMCID: PMC5489052 DOI: 10.2147/ijnrd.s132980] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Semaphorin3A is a secreted protein known to be involved in organogenesis, immune responses and cancer. In the kidney, semaphorin3A is expressed in the glomerular podocytes, distal tubules and collecting tubules, and believed to play a role in the regulation of the kidney development and function. We examined the serum and urinary semaphorin3A levels in 72 patients with renal disease and 5 healthy volunteers. The patients had been diagnosed with thin basement membrane disease (n=4), minimal change nephrotic syndrome (MCNS; n=22), IgA nephritis (n=21), membranous nephropathy (n=16) and focal segmental glomerular sclerosis (n=9). The level of urinary semaphorin3A in MCNS patients tended to be relatively high among all disease groups. We also investigated the urinary semaphorin3A level in 7 patients with MCNS from disease onset to remission during the drug therapy. MCNS patients in pre-remission states had higher urinary semaphorin3A levels than those in post-remission states receiving immunosuppressive therapies. These results suggested that the urinary semaphorin3A level correlates with the MCNS activity. Semaphorin3A has the potential as a biomarker for MCNS to clarify the reactivity for therapy and may be useful in examining other glomerular diseases with proteinuria as well.
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Affiliation(s)
- Akiko Inoue-Torii
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Shinji Kitamura
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Jun Wada
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kenji Tsuji
- Center for Systems Biology, Program in Membrane Biology, Division of Nephrology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, MA, USA
| | - Hirofumi Makino
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Abstract
Podocytes are complex epithelial cells with foot processes that are essential for the integrity and function of the kidney glomerular filters. Podocyte foot processes linked by slit diaphragms constitute signaling platforms that tightly regulate the cell shape and the function of the filtration barrier. Semaphorin (Sema) 3A is a class 3 semaphorin secreted by podocytes that has autocrine and paracrine functions in the kidney. We have shown that Sema3A regulates podocyte shape and that excess Sema3A signaling induces glomerular disease and aggravates diabetic nephropathy. MICAL-1 is an actin-binding protein that mediates Sema3A signals in podocytes. This chapter describes the methods used to examine how Sema3A signaling regulates podocyte shape.
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Affiliation(s)
- Alda Tufro
- Department of Pediatrics/Nephrology, Cell & Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520-8064, USA.
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Goshima Y, Yamashita N, Nakamura F, Sasaki Y. Regulation of dendritic development by semaphorin 3A through novel intracellular remote signaling. Cell Adh Migr 2016; 10:627-640. [PMID: 27392015 DOI: 10.1080/19336918.2016.1210758] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Numerous cell adhesion molecules, extracellular matrix proteins and axon guidance molecules participate in neuronal network formation through local effects at axo-dendritic, axo-axonic or dendro-dendritic contact sites. In contrast, neurotrophins and their receptors play crucial roles in neural wiring by sending retrograde signals to remote cell bodies. Semaphorin 3A (Sema3A), a prototype of secreted type 3 semaphorins, is implicated in axon repulsion, dendritic branching and synapse formation via binding protein neuropilin-1 (NRP1) and the signal transducing protein PlexinAs (PlexAs) complex. This review focuses on Sema3A retrograde signaling that regulates dendritic localization of AMPA-type glutamate receptor GluA2 and dendritic patterning. This signaling is elicited by activation of NRP1 in growth cones and is propagated to cell bodies by dynein-dependent retrograde axonal transport of PlexAs. It also requires interaction between PlexAs and a high-affinity receptor for nerve growth factor, toropomyosin receptor kinase A. We propose a control mechanism by which retrograde Sema3A signaling regulates the glutamate receptor localization through trafficking of cis-interacting PlexAs with GluA2 along dendrites; this remote signaling may be an alternative mechanism to local adhesive contacts for neural network formation.
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Affiliation(s)
- Yoshio Goshima
- a Department of Molecular Pharmacology and Neurobiology , Yokohama City University Graduate School of Medicine , Yokohama , Japan
| | - Naoya Yamashita
- a Department of Molecular Pharmacology and Neurobiology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.,c Department of Biology , Johns Hopkins University , Baltimore , MD , USA
| | - Fumio Nakamura
- a Department of Molecular Pharmacology and Neurobiology , Yokohama City University Graduate School of Medicine , Yokohama , Japan
| | - Yukio Sasaki
- b Functional Structural, Biology Laboratory, Department of Medical Life Science , Yokohama City University Graduate School of Medical Life Science , Suehirocho, Tsurumi-ku, Yokohama , Japan
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Yamashita N, Yamane M, Suto F, Goshima Y. TrkA mediates retrograde semaphorin 3A signaling through plexin A4 to regulate dendritic branching. J Cell Sci 2016; 129:1802-14. [PMID: 26945060 DOI: 10.1242/jcs.184580] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/26/2016] [Indexed: 02/03/2023] Open
Abstract
Semaphorin 3A (Sema3A), a secretory semaphorin, exerts various biological actions through a complex between neuropilin-1 and plexin-As (PlexAs). Sema3A induces retrograde signaling, which is involved in regulating dendritic localization of GluA2 (also known as GRIA2), an AMPA receptor subunit. Here, we investigated a possible interaction between retrograde signaling pathways for Sema3A and nerve growth factor (NGF). Sema3A induces colocalization of PlexA4 (also known as PLXNA4) signals with those of tropomyosin-related kinase A (TrkA, also known as NTRK1) in growth cones, and these colocalized signals were then observed along the axons. The time-lapse imaging of PlexA4 and several TrkA mutants showed that the kinase and dynein-binding activity of TrkA were required for Sema3A-induced retrograde transport of the PlexA4-TrkA complex along the axons. The inhibition of the phosphoinositide 3-kinase (PI3K)-Akt signal, a downstream signaling pathway of TrkA, in the distal axon suppressed Sema3A-induced dendritic localization of GluA2. The knockdown of TrkA suppressed Sema3A-induced dendritic localization of GluA2 and that suppressed Sema3A-regulated dendritic branching both in vitro and in vivo These findings suggest that by interacting with PlexA4, TrkA plays a crucial role in redirecting local Sema3A signaling to retrograde axonal transport, thereby regulating dendritic GluA2 localization and patterning.
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Affiliation(s)
- Naoya Yamashita
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Masayuki Yamane
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
| | - Fumikazu Suto
- National Center of Neurology and Psychiatry, National Institute of Neuroscience, Department of Ultrastructural Research, 4-1-1, Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
| | - Yoshio Goshima
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
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Xia J, Worzfeld T. Semaphorins and Plexins in Kidney Disease. Nephron Clin Pract 2016; 132:93-100. [PMID: 26844545 DOI: 10.1159/000443645] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/17/2015] [Indexed: 11/19/2022] Open
Abstract
Semaphorins are soluble or membrane-bound cues, which control multiple aspects of cell-cell communication, differentiation, morphology and function. Most of their effects are mediated by a family of transmembrane receptors called plexins. Semaphorins and plexins have emerged as central regulators of diverse physiological and pathophysiological processes in various organs. This review summarizes the role of semaphorins and plexins in renal pathophysiology and their potential use as biomarkers of kidney disease.
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Affiliation(s)
- Jingjing Xia
- Department of Dermatology, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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Mahdaviani K, Chess D, Wu Y, Shirihai O, Aprahamian TR. Autocrine effect of vascular endothelial growth factor-A is essential for mitochondrial function in brown adipocytes. Metabolism 2016; 65:26-35. [PMID: 26683794 PMCID: PMC4684900 DOI: 10.1016/j.metabol.2015.09.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 08/31/2015] [Accepted: 09/19/2015] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The obesity epidemic in the United States, as well as the accompanying condition of type 2 diabetes, puts a majority of the population at an increased risk of developing cardiovascular diseases including coronary artery disease, stroke, and myocardial infarction. In contrast to white adipose tissue (WAT), brown adipose tissue (BAT) is well vascularized, rich in mitochondria, and highly oxidative. While it is known that the angiogenic factor VEGF-A is required for brown adipocyte development, the functional consequences and exact mechanism remain to be elucidated. Here, we show that VEGF-A plays an essential autocrine role in the function of BAT. MATERIALS AND METHODS Mouse models were generated with an adipose-specific and macrophage-specific ablation of VEGF-A. Adipose tissue characteristics and thermogenic response were analyzed in vivo, and mitochondrial morphology and oxidative respiration were analyzed in vitro to assess effects of endogenous VEGF-A ablation. RESULTS VEGF-A expression levels are highest in adipocyte precursors compared to immune or endothelial cell populations within both WAT and BAT. Loss of VEGF-A in adipocytes, but not macrophages, results in decreased adipose tissue vascularization, with remarkably diminished thermogenic capacity in vivo. Complete ablation of endogenous VEGF-A decreases oxidative capacity of mitochondria in brown adipocytes. Further, acute ablation of VEGF-A in brown adipocytes in vitro impairs mitochondrial respiration, despite similar mitochondrial mass compared to controls. CONCLUSION These data demonstrate that VEGF-A serves to orchestrate the acquisition of thermogenic capacity of brown adipocytes through mitochondrial function in conjunction with the recruitment of blood vessels.
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Affiliation(s)
- Kiana Mahdaviani
- Section of Endocrinology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - David Chess
- Section of Endocrinology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Yuanyuan Wu
- Section of Endocrinology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Orian Shirihai
- Section of Endocrinology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Tamar R Aprahamian
- Renal Section, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
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31
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Bondeva T, Wolf G. Role of Neuropilin-1 in Diabetic Nephropathy. J Clin Med 2015; 4:1293-311. [PMID: 26239560 PMCID: PMC4485001 DOI: 10.3390/jcm4061293] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/28/2015] [Accepted: 06/09/2015] [Indexed: 02/07/2023] Open
Abstract
Diabetic nephropathy (DN) often develops in patients suffering from type 1 or type 2 diabetes mellitus. DN is characterized by renal injury resulting in proteinuria. Neuropilin-1 (NRP-1) is a single-pass transmembrane receptor protein devoid of enzymatic activity. Its large extracellular tail is structured in several domains, thereby allowing the molecule to interact with multiple ligands linking NRP-1 to different pathways through its signaling co-receptors. NRP-1’s role in nervous system development, immunity, and more recently in cancer, has been extensively investigated. Although its relation to regulation of apoptosis and cytoskeleton organization of glomerular vascular endothelial cells was reported, its function in diabetes mellitus and the development of DN is less clear. Several lines of evidence demonstrate a reduced NRP-1 expression in glycated-BSA cultured differentiated podocytes as well as in glomeruli from db/db mice (a model of type 2 Diabetes) and in diabetic patients diagnosed with DN. In vitro studies of podocytes implicated NRP-1 in the regulation of podocytes’ adhesion to extracellular matrix proteins, cytoskeleton reorganization, and apoptosis via not completely understood mechanisms. However, the exact role of NRP-1 during the onset of DN is not yet understood. This review intends to shed more light on NRP-1 and to present a link between NRP-1 and its signaling complexes in the development of DN.
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Affiliation(s)
- Tzvetanka Bondeva
- Department of Internal Medicine III, University Hospital Jena, Jena, 07747, Germany.
| | - Gunter Wolf
- Department of Internal Medicine III, University Hospital Jena, Jena, 07747, Germany.
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Aggarwal PK, Veron D, Thomas DB, Siegel D, Moeckel G, Kashgarian M, Tufro A. Semaphorin3a promotes advanced diabetic nephropathy. Diabetes 2015; 64:1743-59. [PMID: 25475434 PMCID: PMC4407856 DOI: 10.2337/db14-0719] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 11/26/2014] [Indexed: 01/06/2023]
Abstract
The onset of diabetic nephropathy (DN) is highlighted by glomerular filtration barrier abnormalities. Identifying pathogenic factors and targetable pathways driving DN is crucial to developing novel therapies and improving the disease outcome. Semaphorin3a (sema3a) is a guidance protein secreted by podocytes. Excess sema3a disrupts the glomerular filtration barrier. Here, using immunohistochemistry, we show increased podocyte SEMA3A in renal biopsies from patients with advanced DN. Using inducible, podocyte-specific Sema3a gain-of-function (Sema3a(+)) mice made diabetic with streptozotocin, we demonstrate that sema3a is pathogenic in DN. Diabetic Sema3a(+) mice develop massive proteinuria, renal insufficiency, and extensive nodular glomerulosclerosis, mimicking advanced DN in humans. In diabetic mice, Sema3a(+) exacerbates laminin and collagen IV accumulation in Kimmelstiel-Wilson-like glomerular nodules and causes diffuse podocyte foot process effacement and F-actin collapse via nephrin, αvβ3 integrin, and MICAL1 interactions with plexinA1. MICAL1 knockdown and sema3a inhibition render podocytes not susceptible to sema3a-induced shape changes, indicating that MICAL1 mediates sema3a-induced podocyte F-actin collapse. Moreover, sema3a binding inhibition or podocyte-specific plexinA1 deletion markedly ameliorates albuminuria and abrogates renal insufficiency and the diabetic nodular glomerulosclerosis phenotype of diabetic Sema3a(+) mice. Collectively, these findings indicate that excess sema3a promotes severe diabetic nephropathy and identifies novel potential therapeutic targets for DN.
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Affiliation(s)
- Pardeep K Aggarwal
- Department of Pediatrics/Nephrology, Yale University School of Medicine, New Haven, CT
| | - Delma Veron
- Department of Pediatrics/Nephrology, Yale University School of Medicine, New Haven, CT
| | - David B Thomas
- Department of Pathology, University of Miami Miller School of Medicine, Miami, FL
| | - Dionicio Siegel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA
| | - Gilbert Moeckel
- Department of Pathology, Yale University School of Medicine, New Haven, CT
| | - Michael Kashgarian
- Department of Pathology, Yale University School of Medicine, New Haven, CT
| | - Alda Tufro
- Department of Pediatrics/Nephrology, Yale University School of Medicine, New Haven, CT
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Pawar RD, Goilav B, Xia Y, Herlitz L, Doerner J, Chalmers S, Ghosh K, Zang X, Putterman C. B7x/B7-H4 modulates the adaptive immune response and ameliorates renal injury in antibody-mediated nephritis. Clin Exp Immunol 2015; 179:329-43. [PMID: 25205493 DOI: 10.1111/cei.12452] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2014] [Indexed: 12/12/2022] Open
Abstract
Kidney disease is one of the leading causes of death in patients with lupus and other autoimmune diseases affecting the kidney, and is associated with deposition of antibodies as well as infiltration of T lymphocytes and macrophages, which are responsible for initiation and/or exacerbation of inflammation and tissue injury. Current treatment options have relatively limited efficacy; therefore, novel targets need to be explored. The co-inhibitory molecule, B7x, a new member of the B7 family expressed predominantly by non-lymphoid tissues, has been shown to inhibit the proliferation, activation and functional responses of CD4 and CD8 T cells. In this study, we found that B7x was expressed by intrinsic renal cells, and was up-regulated upon stimulation with inflammatory triggers. After passive administration of antibodies against glomerular antigens, B7x(-/-) mice developed severe renal injury accompanied by a robust adaptive immune response and kidney up-regulation of inflammatory mediators, as well as local infiltration of T cells and macrophages. Furthermore, macrophages in the spleen of B7x(-/-) mice were polarized to an inflammatory phenotype. Finally, treatment with B7x-immunoglobulin (Ig) in this nephritis model decreased kidney damage and reduced local inflammation. We propose that B7x can modulate kidney damage in autoimmune diseases including lupus nephritis and anti-glomerular basement membrane disease. Thus, B7x mimetics may be a novel therapeutic option for treatment of immune-mediated kidney disease.
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Affiliation(s)
- R D Pawar
- The Division of Rheumatology, Albert Einstein College of Medicine, NY, USA; Department of Microbiology & Immunology, Albert Einstein College of Medicine, NY, USA
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Wedel J, Bruneau S, Kochupurakkal N, Boneschansker L, Briscoe DM. Chronic allograft rejection: a fresh look. Curr Opin Organ Transplant 2015; 20:13-20. [PMID: 25563987 PMCID: PMC4461362 DOI: 10.1097/mot.0000000000000155] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW New developments suggest that the graft itself and molecules expressed within the graft microenvironment dictate the phenotype and evolution of chronic rejection. RECENT FINDINGS Once ischemia-reperfusion injury, cellular and humoral immune responses target the microvasculature, the associated local tissue hypoxia results in hypoxia-inducible factor 1α-dependent expression of pro-inflammatory and proangiogenic growth factors including vascular endothelial growth factor (VEGF) as a physiological response to injury. Local expression of VEGF can promote the recruitment of alloimune T cells into the graft. mTOR/Akt signaling within endothelial cells regulates cytokine- and alloantibody-induced activation and proliferation and their proinflammatory phenotype. Inhibition of mTOR and/or Akt results in an anti-inflammatory phenotype and enables the expression of coinhibitory molecules that limit local T cell reactivation and promotes immunoregulation. Semaphorin family molecules may bind to neuropilin-1 on regulatory T cell subsets to stabilize functional responses. Ligation of neuropilin-1 on Tregs also inhibits Akt-induced responses suggesting common theme for enhancing local immunoregulation and long-term graft survival. SUMMARY Events within the graft initiated by mTOR/Akt-induced signaling promote the development of chronic rejection. Semaphorin-neuropilin biology represents a novel avenue for targeting this biology and warrants further investigation.
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Affiliation(s)
- Johannes Wedel
- Transplant Research Program, Pediatric Transplant Center, Boston Children's Hospital, Boston MA
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Boston, MA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Sarah Bruneau
- Transplant Research Program, Pediatric Transplant Center, Boston Children's Hospital, Boston MA
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Boston, MA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Nora Kochupurakkal
- Transplant Research Program, Pediatric Transplant Center, Boston Children's Hospital, Boston MA
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Boston, MA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Leo Boneschansker
- Transplant Research Program, Pediatric Transplant Center, Boston Children's Hospital, Boston MA
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Boston, MA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - David M. Briscoe
- Transplant Research Program, Pediatric Transplant Center, Boston Children's Hospital, Boston MA
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Boston, MA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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Ito T, Bai T, Tanaka T, Yoshida K, Ueyama T, Miyajima M, Negishi T, Kawasaki T, Takamatsu H, Kikutani H, Kumanogoh A, Yukawa K. Semaphorin 4D induces vaginal epithelial cell apoptosis to control mouse postnatal vaginal tissue remodeling. Mol Med Rep 2014; 11:829-36. [PMID: 25351707 PMCID: PMC4262505 DOI: 10.3892/mmr.2014.2773] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 09/09/2014] [Indexed: 11/18/2022] Open
Abstract
The opening of the mouse vaginal cavity to the skin is a postnatal tissue remodeling process that occurs at approximately five weeks of age for the completion of female genital tract maturation at puberty. The tissue remodeling process is primarily composed of a hormonally triggered apoptotic process predominantly occurring in the epithelium of the distal section of the vaginal cavity. However, the detailed mechanism underlying the apoptotic induction remains to be elucidated. In the present study, it was observed that the majority of BALB/c mice lacking the class 4 semaphorin, semaphorin 4D (Sema4D), developed imperforate vagina and hydrometrocolpos resulting in a perpetually unopened vaginal cavity regardless of a normal estrogen level comparable with that in wild-type (WT) mice. Administration of β-estradiol to infant Sema4D-deficient (Sema4D−/−) mice did not induce precocious vaginal opening, which was observed in WT mice subjected to the same β-estradiol administration, excluding the possibility that the closed vaginal phenotype was due to insufficient estrogen secretion at the time of vaginal opening. In order to assess the role of Sema4D in the postnatal vaginal tissue remodeling process, the expression of Sema4D and its receptor, plexin-B1, was examined as well as the level of apoptosis in the vaginal epithelia of five-week-old WT and Sema4D−/− mice. Immunohistochemical analyses confirmed the localization of Sema4D and plexin-B1 in the mouse vaginal epithelia. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and immunohistochemistry detecting activated caspase-3 revealed significantly fewer apoptotic cells in situ in the vaginal mucosa of five-week-old Sema4D−/− mice compared with WT mice. The addition of recombinant Sema4D to Sema4D−/− vaginal epithelial cells in culture significantly enhanced apoptosis of the vaginal epithelial cells, demonstrating the apoptosis-inducing activity of Sema4D. The experimental reduction of plexin-B1 expression in vaginal epithelial cells demonstrated the integral role of plexin-B1 in Sema4D-induced apoptotic cell death. These results suggest a non-redundant role of Sema4D in the postnatal tissue remodeling process in five-week-old BALB/c mice, which involves the induction of vaginal epithelial cell apoptosis through Sema4D binding to plexin-B1.
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Affiliation(s)
- Takuji Ito
- Department of Physiology, Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468‑8503, Japan
| | - Tao Bai
- Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama 641‑8509, Japan
| | - Tetsuji Tanaka
- Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama 641‑8509, Japan
| | - Kenji Yoshida
- Department of Physiology, Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468‑8503, Japan
| | - Takashi Ueyama
- Department of Anatomy, Wakayama Medical University, Wakayama 641‑8509, Japan
| | - Masayasu Miyajima
- Institute for Animal Experimentation, Wakayama Medical University, Wakayama 641‑8509, Japan
| | - Takayuki Negishi
- Department of Physiology, Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468‑8503, Japan
| | - Takahiko Kawasaki
- Division of Brain Function, National Institute of Genetics, Graduate University for Advanced Studies (Sokendai), Mishima 411‑8540, Japan
| | - Hyota Takamatsu
- Department of Immunopathology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565‑0871, Japan
| | - Hitoshi Kikutani
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565‑0871, Japan
| | - Atsushi Kumanogoh
- Department of Immunopathology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565‑0871, Japan
| | - Kazunori Yukawa
- Department of Physiology, Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468‑8503, Japan
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Ito T, Bai T, Tanaka T, Yoshida K, Ueyama T, Miyajima M, Negishi T, Kawasaki T, Takamatsu H, Kikutani H, Kumanogoh A, Yukawa K. Estrogen-dependent proteolytic cleavage of semaphorin 4D and plexin-B1 enhances semaphorin 4D-induced apoptosis during postnatal vaginal remodeling in pubescent mice. PLoS One 2014; 9:e97909. [PMID: 24841081 PMCID: PMC4026538 DOI: 10.1371/journal.pone.0097909] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/25/2014] [Indexed: 01/15/2023] Open
Abstract
Around the fifth week after birth, the vaginal cavity in female mouse pups opens to the overlaying skin. This postnatal tissue remodeling of the genital tract occurs during puberty, and it largely depends upon hormonally induced apoptosis that mainly occurs in the epithelium at the lower part of the mouse vaginal cavity. Previously, we showed that most BALB/c mice lacking the class IV Semaphorin (Sema4D) develop imperforate vagina and hydrometrocolpos; therefore, we reasoned that the absence of Sema4D-induced apoptosis in vaginal epithelial cells may cause the imperforate vagina. Sema4D signals via the Plexin-B1 receptor; nevertheless detailed mechanisms mediating this hormonally triggered apoptosis are not fully documented. To investigate the estrogen-dependent control of Sema4D signaling during the apoptosis responsible for mouse vaginal opening, we examined structural and functional modulation of Sema4D, Plexin-B1, and signaling molecules by analyzing both wild-type and Sema4D−/− mice with or without ovariectomy. Both the release of soluble Sema4D and the conversion of Plexin-B1 by proteolytic processing in vaginal tissue peaked 5 weeks after birth of wild-type BALB/c mice at the time of vaginal opening. Estrogen supplementation of ovariectomized wild-type mice revealed that both the release of soluble Sema4D and the conversion of Plexin-B1 into an active form were estrogen-dependent and concordant with apoptosis. Estrogen supplementation of ovariectomized Sema4D−/− mice did not induce massive vaginal apoptosis in 5-week-old mice; therefore, Sema4D may be an essential apoptosis-inducing ligand that acts downstream of estrogen action in vaginal epithelium during this postnatal tissue remodeling. Analysis of ovariectomized mice also indicated that Sema4D contributed to estrogen-dependent dephosphorylation of Akt and ERK at the time of vaginal opening. Based on our results, we propose that apoptosis in vaginal epithelium during postnatal vaginal opening is induced by enhanced Sema4D signaling that is caused by estrogen-dependent structural changes of Sema4D and Plexin-B1.
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Affiliation(s)
- Takuji Ito
- Department of Physiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | - Tao Bai
- Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama, Japan
| | - Tetsuji Tanaka
- Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama, Japan
| | - Kenji Yoshida
- Department of Physiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | - Takashi Ueyama
- Department of Anatomy and Cell Biology, Wakayama Medical University, Wakayama, Japan
| | - Masayasu Miyajima
- Laboratory Animal Center, Wakayama Medical University, Wakayama, Japan
| | - Takayuki Negishi
- Department of Physiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | - Takahiko Kawasaki
- Division of Brain Function, National Institute of Genetics, Graduate University for Advanced Studies (Sokendai), Mishima, Japan
| | - Hyota Takamatsu
- Department of Immunopathology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Hitoshi Kikutani
- Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Atsushi Kumanogoh
- Department of Immunopathology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Kazunori Yukawa
- Department of Physiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
- * E-mail:
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Aghajanian H, Choi C, Ho VC, Gupta M, Singh MK, Epstein JA. Semaphorin 3d and semaphorin 3e direct endothelial motility through distinct molecular signaling pathways. J Biol Chem 2014; 289:17971-9. [PMID: 24825896 DOI: 10.1074/jbc.m113.544833] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Class 3 semaphorins were initially described as axonal growth cone guidance molecules that signal through plexin and neuropilin coreceptors and since then have been established to be regulators of vascular development. Semaphorin 3e (Sema3e) has been shown previously to repel endothelial cells and is the only class 3 semaphorin known to be capable of signaling via a plexin receptor without a neuropilin coreceptor. Sema3e signals through plexin D1 (Plxnd1) to regulate vascular patterning by modulating the cytoskeleton and focal adhesion structures. We showed recently that semaphorin 3d (Sema3d) mediates endothelial cell repulsion and pulmonary vein patterning during embryogenesis. Here we show that Sema3d and Sema3e affect human umbilical vein endothelial cells similarly but through distinct molecular signaling pathways. Time-lapse imaging studies show that both Sema3d and Sema3e can inhibit cell motility and migration, and tube formation assays indicate that both can impede tubulogenesis. Endothelial cells incubated with either Sema3d or Sema3e demonstrate a loss of actin stress fibers and focal adhesions. However, the addition of neuropilin 1 (Nrp1)-blocking antibody or siRNA knockdown of Nrp1 inhibits Sema3d-mediated, but not Sema3e-mediated, cytoskeletal reorganization, and siRNA knockdown of Nrp1 abrogates Sema3d-mediated, but not Sema3e-mediated, inhibition of tubulogenesis. On the other hand, endothelial cells deficient in Plxnd1 are resistant to endothelial repulsion mediated by Sema3e but not Sema3d. Unlike Sema3e, Sema3d incubation results in phosphorylation of Akt in human umbilical vein endothelial cells, and inhibition of the PI3K/Akt pathway blocks the endothelial guidance and cytoskeletal reorganization functions of Sema3d but not Sema3e.
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Affiliation(s)
- Haig Aghajanian
- From the Department of Cell and Developmental Biology and the Cardiovascular Institute and Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Connie Choi
- From the Department of Cell and Developmental Biology and the Cardiovascular Institute and Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Vivienne C Ho
- From the Department of Cell and Developmental Biology and the Cardiovascular Institute and Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Mudit Gupta
- From the Department of Cell and Developmental Biology and the Cardiovascular Institute and Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Manvendra K Singh
- From the Department of Cell and Developmental Biology and the Cardiovascular Institute and Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Jonathan A Epstein
- From the Department of Cell and Developmental Biology and the Cardiovascular Institute and Institute for Regenerative Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
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Tufro A. Semaphorin3a signaling, podocyte shape, and glomerular disease. Pediatr Nephrol 2014; 29:751-5. [PMID: 24464477 PMCID: PMC3992269 DOI: 10.1007/s00467-013-2743-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 12/17/2013] [Accepted: 12/18/2013] [Indexed: 12/21/2022]
Abstract
Semaphorin3a (sema3a), a member of class 3 semaphorins, is a guidance protein that regulates angiogenesis, branching morphogenesis, axon growth, and cell migration, and has pleiotropic roles on organogenesis, immune response, and cancer. Sema3a is secreted by podocytes and is required for normal kidney patterning and glomerular filtration barrier development. We recently discovered that after completion of kidney development, Sema3a gain-of-function in podocytes leads to proteinuric glomerular disease in mice. Excess sema3a causes foot process effacement, glomerular basement lamination, and endothelial damage in vivo, and disrupts cell autonomously podocyte shape by down-regulating nephrin and inhibiting αvβ3 integrin. We identified a novel direct interaction between nephrin and plexinA1, the sema3a signaling receptor. Nephrin-plexinA1 interaction links the slit-diaphragm signaling complex to extracellular sema3a signals. Hence, sema3a functions as an extracellular negative regulator of the structure and function of the glomerular filtration barrier.
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Affiliation(s)
- Alda Tufro
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, PO Box 208064, New Haven, CT, 06520-8064, USA,
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A multicolor podocyte reporter highlights heterogeneous podocyte changes in focal segmental glomerulosclerosis. Kidney Int 2013; 85:972-80. [PMID: 24284512 PMCID: PMC3987991 DOI: 10.1038/ki.2013.463] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 08/19/2013] [Accepted: 09/19/2013] [Indexed: 02/06/2023]
Abstract
In contrast to most glomerular diseases, the injury pattern in focal segmental glomerulosclerosis (FSGS) is highly heterogeneous, even though podocytes are genetically identical and exposed to the same environmental factors. To understand changes in individual podocytes, we generated and analyzed a stochastic multicolor Cre-reporter, encoding four fluorescent proteins. In these animals podocytes were randomly labeled allowing individual cells and their foot processes to be distinguished. In healthy animals podocyte size and structure showed little cell to cell variability. In the doxorubicin-induced FSGS model, fluorescent-labeled glomerular podocyte numbers decreased and fluorescent cells could be recovered from the urine. The size of the remaining podocytes showed a high degree of heterogeneity, some cells remained small, while others enlarged. Both enlarged and non-enlarged podocytes showed alterations in their foot process morphology. Thus, by the virtue of a multicolor cre-reporter, individual podocytes could be viewed in real time at a cellular resolution indicating a heterogeneous podocyte injury response during the pathogenesis of FSGS.
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Reidy KJ, Aggarwal PK, Jimenez JJ, Thomas DB, Veron D, Tufro A. Excess podocyte semaphorin-3A leads to glomerular disease involving plexinA1-nephrin interaction. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:1156-1168. [PMID: 23954273 DOI: 10.1016/j.ajpath.2013.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/23/2013] [Accepted: 06/26/2013] [Indexed: 12/29/2022]
Abstract
Semaphorin-3A (Sema3a), a guidance protein secreted by podocytes, is essential for normal kidney patterning and glomerular filtration barrier development. Here, we report that podocyte-specific Sema3a gain-of-function in adult mice leads to proteinuric glomerular disease involving the three layers of the glomerular filtration barrier. Reversibility of the glomerular phenotype upon removal of the transgene induction provided proof-of-principle of the cause-and-effect relationship between podocyte Sema3a excess and glomerular disease. Mechanistically, excess Sema3a induces dysregulation of nephrin, matrix metalloproteinase 9, and αvβ3 integrin in vivo. Sema3a cell-autonomously disrupts podocyte shape. We identified a novel direct interaction between the Sema3a signaling receptor plexinA1 and nephrin, linking extracellular Sema3a signals to the slit-diaphragm signaling complex. We conclude that Sema3a functions as an extracellular negative regulator of the structure and function of the glomerular filtration barrier in the adult kidney. Our findings demonstrate a crosstalk between Sema3a and nephrin signaling pathways that is functionally relevant both in vivo and in vitro.
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Affiliation(s)
- Kimberly J Reidy
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York
| | - Pardeep K Aggarwal
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Juan J Jimenez
- Imaging Facility, Albert Einstein College of Medicine, Bronx, New York
| | - David B Thomas
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York
| | - Delma Veron
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Alda Tufro
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut.
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Hughes A, Kleine-Albers J, Helfrich MH, Ralston SH, Rogers MJ. A class III semaphorin (Sema3e) inhibits mouse osteoblast migration and decreases osteoclast formation in vitro. Calcif Tissue Int 2012; 90:151-62. [PMID: 22227882 PMCID: PMC3271215 DOI: 10.1007/s00223-011-9560-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 12/04/2011] [Indexed: 12/11/2022]
Abstract
Originally identified as axonal guidance cues, semaphorins are expressed throughout many different tissues and regulate numerous non-neuronal processes. We demonstrate that most class III semaphorins are expressed in mouse osteoblasts and are differentially regulated by cell growth and differentiation: Sema3d expression is increased and Sema3e expression decreased during proliferation in culture, while expression of Sema3a is unaffected by cell density but increases in cultures of mineralizing osteoblasts. Expression of Sema3a, -3e, and -3d is also differentially regulated by osteogenic stimuli; inhibition of GSK3β decreased expression of Sema3a and -3e, while 1,25-(OH)(2)D(3) increased expression of Sema3e. Parathyroid hormone had no effect on expression of Sema3a, -3b, or -3d. Osteoblasts, macrophages, and osteoclasts express the Sema3e receptor PlexinD1, suggesting an autocrine and paracrine role for Sema3e. No effects of recombinant Sema3e on osteoblast proliferation, differentiation, or mineralization were observed; but Sema3e did inhibit the migration of osteoblasts in a wound-healing assay. The formation of multinucleated, tartrate-resistant acid phosphatase-positive osteoclasts was decreased by 81% in cultures of mouse bone marrow macrophages incubated with 200 ng/mL Sema3e. Correspondingly, decreased expression of osteoclast markers (Itgb3, Acp5, Cd51, Nfatc1, CalcR, and Ctsk) was observed by qPCR in macrophage cultures differentiated in the presence of Sema3e. Our results demonstrate that class III semaphorins are expressed by osteoblasts and differentially regulated by differentiation, mineralization, and osteogenic stimuli. Sema3e is a novel inhibitor of osteoclast formation in vitro and may play a role in maintaining local bone homeostasis, potentially acting as a coupling factor between osteoclasts and osteoblasts.
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Affiliation(s)
- Alun Hughes
- Musculoskeletal Research Programme, School of Medicine & Dentistry, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB252ZD UK
| | - Jennifer Kleine-Albers
- Musculoskeletal Research Programme, School of Medicine & Dentistry, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB252ZD UK
| | - Miep H. Helfrich
- Musculoskeletal Research Programme, School of Medicine & Dentistry, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB252ZD UK
| | - Stuart H. Ralston
- Molecular Medicine Centre, Western General Hospital, University of Edinburgh, Crewe Road, Edinburgh, EH42XU UK
| | - Michael J. Rogers
- Musculoskeletal Research Programme, School of Medicine & Dentistry, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB252ZD UK
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Evans TL, Blice-Baum AC, Mihailescu MR. Analysis of the Fragile X mental retardation protein isoforms 1, 2 and 3 interactions with the G-quadruplex forming semaphorin 3F mRNA. ACTA ACUST UNITED AC 2012; 8:642-9. [DOI: 10.1039/c1mb05322a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Vadasz Z, Ben-Izhak O, Bejar J, Sabo E, Kessel A, Storch S, Toubi E. The involvement of immune semaphorins and neuropilin-1 in lupus nephritis. Lupus 2011; 20:1466-1473. [DOI: 10.1177/0961203311417034] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Background and objectives: Neuropilin-1 (NP-1), a functional vascular endothelial growth factor (VEGF) receptor, is important in the priming of resting T cells and contributes to the development of peripheral tolerance. Semaphorins, a family of axon guidance molecules, has been found to be involved in regulating the immune system.The aim of this study was to explore the involvement of NP-1 and semaphorins in lupus glomerulonephritis (LGN).Methods: Twelve kidney biopsies from LGN patients and five normal biopsies were examined in this study. In addition, eight biopsies from patients with primary nephropathy and proteinuria were included serving as a disease control group. Biopsies were stained with anti-VEGF, NP-1, and semaphorins. The Image Pro-Plus software was used to measure the intensity and extent of staining. The correlation with clinico-pathological parameters was evaluated.Results: VEGF expression was slightly higher in LGN. NP-1 and semaphorins were stained with significantly higher intensity in LGN when compared with both the normal and the disease control groups. NP-1 deposits were found only in damaged glomerulus areas and positively correlated with clinico-pathological parameters of renal disease (a statistical trend). However, the semaphorins were found in inverse correlations.Discussion: Being present in normal and slightly increased in diseased glomeruli, VEGF is considered protective during inflammation. Increased NP-1 expression in LGN may intensify the possible protective effect of VEGF, thereby preventing endothelial damage. However, one should consider the possibility that increased NP-1 expression is harmful and could play a role in the damage of LGN. NP-1 is suggested to be a reliable marker differentiating focal versus diffuse LGN. Semaphorin 3A can serve as a histological marker for tubular damage. The altered ability of kidneys to secrete semaphorins during advanced renal damage may in part explain its inverse correlation with renal function. Further work is needed in order to better understand the role of NP-1 and semaphorins in LGN.
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Affiliation(s)
- Z Vadasz
- Division of Allergy and Clinical Immunology, Bnai-Zion Medical Center, Haifa, Israel
| | - O Ben-Izhak
- Department of Pathology, Rambam Medical Center, Haifa, Israel
| | - J Bejar
- Department of Pathology, Bnai Zion Medical Center, Haifa, Israel
| | - E Sabo
- Department of Pathology, Rambam Medical Center, Haifa, Israel
| | - A Kessel
- Division of Allergy and Clinical Immunology, Bnai-Zion Medical Center, Haifa, Israel
| | - S Storch
- Nephrology Unit, Bnai Zion Medical Center and The Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - E Toubi
- Division of Allergy and Clinical Immunology, Bnai-Zion Medical Center, Haifa, Israel
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Brunskill EW, Georgas K, Rumballe B, Little MH, Potter SS. Defining the molecular character of the developing and adult kidney podocyte. PLoS One 2011; 6:e24640. [PMID: 21931791 PMCID: PMC3169617 DOI: 10.1371/journal.pone.0024640] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 08/15/2011] [Indexed: 02/01/2023] Open
Abstract
Background The podocyte is a remarkable cell type, which encases the capillaries of the kidney glomerulus. Although mesodermal in origin it sends out axonal like projections that wrap around the capillaries. These extend yet finer projections, the foot processes, which interdigitate, leaving between them the slit diaphragms, through which the glomerular filtrate must pass. The podocytes are a subject of keen interest because of their key roles in kidney development and disease. Methodology/Principal Findings In this report we identified and characterized a novel transgenic mouse line, MafB-GFP, which specifically marked the kidney podocytes from a very early stage of development. These mice were then used to facilitate the fluorescent activated cell sorting based purification of podocytes from embryos at E13.5 and E15.5, as well as adults. Microarrays were then used to globally define the gene expression states of podocytes at these different developmental stages. A remarkable picture emerged, identifying the multiple sets of genes that establish the neuronal, muscle, and phagocytic properties of podocytes. The complete combinatorial code of transcription factors that create the podocyte was characterized, and the global lists of growth factors and receptors they express were defined. Conclusions/Significance The complete molecular character of the in vivo podocyte is established for the first time. The active molecular functions and biological processes further define their unique combination of features. The results provide a resource atlas of gene expression patterns of developing and adult podocytes that will help to guide further research of these incredible cells.
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Affiliation(s)
- Eric W. Brunskill
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
| | - Kylie Georgas
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Bree Rumballe
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Melissa H. Little
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - S. Steven Potter
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center and the University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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Reidy K, Tufro A. Semaphorins in kidney development and disease: modulators of ureteric bud branching, vascular morphogenesis, and podocyte-endothelial crosstalk. Pediatr Nephrol 2011; 26:1407-12. [PMID: 21336944 PMCID: PMC3397149 DOI: 10.1007/s00467-011-1769-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/12/2010] [Accepted: 01/06/2011] [Indexed: 12/14/2022]
Abstract
Semaphorins are guidance proteins that play important roles in organogenesis and disease. Expression of class 3 semaphorins and their receptors is regulated during kidney development. Gain- and loss-of-function experiments demonstrated that tight semaphorin3a gene dosage is required for podocyte differentiation, and for the establishment of a normal glomerular filtration barrier. Sema3a modulates kidney vascular patterning acting as a negative regulator of endothelial cell migration and survival. Excess podocyte semaphorin3a expression causes glomerular disease in mice. In addition, Sema3a is a negative regulator of ureteric bud branching, whereas Sema3c is a positive regulator of ureteric bud and endothelial cell branching morphogenesis. In summary, secreted semaphorins modulate ureteric bud branching, vascular patterning, and podocyte-endothelial crosstalk, suggesting that they play a role in renal disease. Understanding the signaling pathways downstream from semaphorin receptors will provide insight into the mechanism of action of semaphorins in renal pathology.
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Affiliation(s)
- Kimberly Reidy
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alda Tufro
- Yale University School of Medicine, 333 Cedar Avenue, New Haven, CT 06520, USA
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Veron D, Bertuccio CA, Marlier A, Reidy K, Garcia AM, Jimenez J, Velazquez H, Kashgarian M, Moeckel GW, Tufro A. Podocyte vascular endothelial growth factor (Vegf₁₆₄) overexpression causes severe nodular glomerulosclerosis in a mouse model of type 1 diabetes. Diabetologia 2011; 54:1227-41. [PMID: 21318407 PMCID: PMC3397150 DOI: 10.1007/s00125-010-2034-z] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 11/19/2010] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS The pathogenic role of excessive vascular endothelial growth factor (VEGF)-A in diabetic nephropathy has not been defined. We sought to test whether increased podocyte VEGF-A signalling determines the severity of diabetic glomerulopathy. METHODS Podocyte-specific, doxycycline-inducible Vegf₁₆₄ (the most abundant Vegfa isoform) overexpressing adult transgenic mice were made diabetic with low doses of streptozotocin and examined 12 weeks after onset of diabetes. We studied diabetic and non-diabetic transgenic mice fed a standard or doxycycline-containing diet. VEGF-A and albuminuria were measured by ELISA, creatinine was measured by HPLC, renal morphology was examined by light and electron microscopy, and gene expression was assessed by quantitative PCR, immunoblotting and immunohistochemistry. RESULTS Podocyte Vegf₁₆₄ overexpression in our mouse model of diabetes resulted in advanced diabetic glomerulopathy, characterised by Kimmelstiel-Wilson-like nodular glomerulosclerosis, microaneurysms, mesangiolysis, glomerular basement membrane thickening, podocyte effacement and massive proteinuria associated with hyperfiltration. It also led to increased VEGF receptor 2 and semaphorin3a levels, as well as nephrin and matrix metalloproteinase-2 downregulation, whereas circulating VEGF-A levels were similar to those in control diabetic mice. CONCLUSIONS/INTERPRETATION Collectively, these data demonstrate that increased podocyte Vegf₁₆₄ signalling dramatically worsens diabetic nephropathy in a streptozotocin-induced mouse model of diabetes, resulting in nodular glomerulosclerosis and massive proteinuria. This suggests that local rather than systemic VEGF-A levels determine the severity of diabetic nephropathy and that semaphorin3a signalling and matrix metalloproteinase-2 dysregulation are mechanistically involved in severe diabetic glomerulopathy.
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Affiliation(s)
- D. Veron
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, P.O. Box 208064, New Haven, CT 06520-8064, USA
| | - C. A. Bertuccio
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, P.O. Box 208064, New Haven, CT 06520-8064, USA
| | - A. Marlier
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - K. Reidy
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - A. M. Garcia
- Department of Internal Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - J. Jimenez
- Analytical Imaging Facility, Albert Einstein College of Medicine, Bronx, NY, USA
| | - H. Velazquez
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - M. Kashgarian
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - G. W. Moeckel
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - A. Tufro
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, P.O. Box 208064, New Haven, CT 06520-8064, USA
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Gene expression of neuropilin-1 and its receptors, VEGF/Semaphorin 3a, in normal and cancer cells. Cell Biochem Biophys 2011; 59:39-47. [PMID: 20711684 DOI: 10.1007/s12013-010-9109-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Extracellular domains of the transmembrane glycoprotein, neuropilin-1 (Np1), specifically bind an array of factors and co-receptors including class-3 semaphorins (Sema3a), vascular endothelial growth factor (VEGF), hepatocyte growth factor, platelet-derived growth factor BB, transforming growth factor-β 1 (TGF-β1), and fibroblast growth factor2 (FGF2). Np1 may have a role in immune response, tumor cell growth, and angiogenesis, but its relative expression in comparison to its co-primary receptors, VEGF and Sema3a, is not known. In this study we determined the mRNA expression of Np1 and its co-receptors, VEGF and Sema3a, and the ratio of VEGF/Sema3a in different human and rodent cell lines. Expression of Np1, VEGF and Sema3a is very low in cells derived from normal tissues, but these proteins are highly expressed in tumor-derived cells. Furthermore, the ratio of VEGF/Sema3a is highly variable in different tumor cells. The elevated mRNA expression of Np1 and its putative receptors in tumor cells suggests a role for these proteins in tumor cell migration and angiogenesis. As different tumor cells exhibit varying VEGF/Sema3a ratios, it appears that cancer cells show differential response to angiogenic factors. These results bring to light the individual variation among the cancer-related genes, Np1, VEGF, and Sema3a, and provide an important impetus for the possible personalized therapeutic approaches for cancer patients.
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48
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Gay CM, Zygmunt T, Torres-Vázquez J. Diverse functions for the semaphorin receptor PlexinD1 in development and disease. Dev Biol 2011; 349:1-19. [PMID: 20880496 PMCID: PMC2993764 DOI: 10.1016/j.ydbio.2010.09.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 09/14/2010] [Accepted: 09/18/2010] [Indexed: 01/13/2023]
Abstract
Plexins are a family of single-pass transmembrane proteins that serve as cell surface receptors for Semaphorins during the embryonic development of animals. Semaphorin-Plexin signaling is critical for many cellular aspects of organogenesis, including cell migration, proliferation and survival. Until recently, little was known about the function of PlexinD1, the sole member of the vertebrate-specific PlexinD (PlxnD1) subfamily. Here we review novel findings about PlxnD1's roles in the development of the cardiovascular, nervous and immune systems and salivary gland branching morphogenesis and discuss new insights concerning the molecular mechanisms of PlxnD1 activity.
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Affiliation(s)
- Carl M Gay
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University Langone Medical Center, 540 First Avenue, 4th floor, lab 14, New York, NY 10016, USA
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Warsow G, Greber B, Falk SSI, Harder C, Siatkowski M, Schordan S, Som A, Endlich N, Schöler H, Repsilber D, Endlich K, Fuellen G. ExprEssence--revealing the essence of differential experimental data in the context of an interaction/regulation net-work. BMC SYSTEMS BIOLOGY 2010; 4:164. [PMID: 21118483 PMCID: PMC3012047 DOI: 10.1186/1752-0509-4-164] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 11/30/2010] [Indexed: 12/15/2022]
Abstract
Background Experimentalists are overwhelmed by high-throughput data and there is an urgent need to condense information into simple hypotheses. For example, large amounts of microarray and deep sequencing data are becoming available, describing a variety of experimental conditions such as gene knockout and knockdown, the effect of interventions, and the differences between tissues and cell lines. Results To address this challenge, we developed a method, implemented as a Cytoscape plugin called ExprEssence. As input we take a network of interaction, stimulation and/or inhibition links between genes/proteins, and differential data, such as gene expression data, tracking an intervention or development in time. We condense the network, highlighting those links across which the largest changes can be observed. Highlighting is based on a simple formula inspired by the law of mass action. We can interactively modify the threshold for highlighting and instantaneously visualize results. We applied ExprEssence to three scenarios describing kidney podocyte biology, pluripotency and ageing: 1) We identify putative processes involved in podocyte (de-)differentiation and validate one prediction experimentally. 2) We predict and validate the expression level of a transcription factor involved in pluripotency. 3) Finally, we generate plausible hypotheses on the role of apoptosis, cell cycle deregulation and DNA repair in ageing data obtained from the hippocampus. Conclusion Reducing the size of gene/protein networks to the few links affected by large changes allows to screen for putative mechanistic relationships among the genes/proteins that are involved in adaptation to different experimental conditions, yielding important hypotheses, insights and suggestions for new experiments. We note that we do not focus on the identification of 'active subnetworks'. Instead we focus on the identification of single links (which may or may not form subnetworks), and these single links are much easier to validate experimentally than submodules. ExprEssence is available at http://sourceforge.net/projects/expressence/.
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Affiliation(s)
- Gregor Warsow
- Institute for Biostatistics and Informatics in Medicine and Ageing Research, University of Rostock, Ernst-Heydemann-Strasse 8, Rostock, Germany
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Recombinant bacterial expression and purification of human fragile X mental retardation protein isoform 1. Protein Expr Purif 2010; 74:242-7. [PMID: 20541608 DOI: 10.1016/j.pep.2010.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 06/04/2010] [Accepted: 06/04/2010] [Indexed: 01/30/2023]
Abstract
The loss of expression of the fragile X mental retardation protein (FMRP) leads to fragile X syndrome. FMRP has two types of RNA binding domains, two K-homology domains and an arginine-glycine-glycine box domain, and it is proposed to act as a translation regulator of specific messenger RNA. The interest to produce sufficient quantities of pure recombinant FMRP for biochemical and biophysical studies is high. However, the recombinant bacterial expression of FMRP has had limited success, and subsequent recombinant eukaryotic and in vitro expression has also resulted in limited success. In addition, the in vitro and eukaryotic expression systems may produce FMRP which is posttranslationally modified, as phosphorylation and arginine methylation have been shown to occur on FMRP. In this study, we have successfully isolated the conditions for recombinant expression, purification and long-term storage of FMRP using Escherichia coli, with a high yield. The expression of FMRP using E. coli renders the protein devoid of the posttranslational modifications of phosphorylation and arginine methylation, allowing the study of the direct effects of these modifications individually and simultaneously. In order to assure that FMRP retained activity throughout the process, we used fluorescence spectroscopy to assay the binding activity of the FMRP arginine-glycine-glycine box for the semaphorin 3F mRNA and confirmed that FMRP remained active.
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