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Mahrous NN, Jamous YF, Almatrafi AM, Fallatah DI, Theyab A, Alanati BH, Alsagaby SA, Alenazi MK, Khan MI, Hawsawi YM. A Current Landscape on Alport Syndrome Cases: Characterization, Therapy and Management Perspectives. Biomedicines 2023; 11:2762. [PMID: 37893135 PMCID: PMC10604007 DOI: 10.3390/biomedicines11102762] [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: 09/09/2023] [Revised: 09/30/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
Alport syndrome (AS) is a rare genetic disorder categorized by the progressive loss of kidney function, sensorineural hearing loss and eye abnormalities. It occurs due to mutations in three genes that encode for the alpha chains of type IV collagen. Globally, the disease is classified based on the pattern of inheritance into X-linked AS (XLAS), which is caused by pathogenic variants in COL4A5, representing 80% of AS. Autosomal recessive AS (ARAS), caused by mutations in either COL4A3 or COL4A4, represents 15% of AS. Autosomal dominant AS (ADAS) is rare and has been recorded in 5% of all cases due to mutations in COL4A3 or COL4A4. This review provides updated knowledge about AS including its clinical and genetic characteristics in addition to available therapies that only slow the progression of the disease. It also focuses on reported cases in Saudi Arabia and their prevalence. Moreover, we shed light on advances in genetic technologies like gene editing using CRISPR/Cas9 technology, the need for an early diagnosis of AS and managing the progression of the disease. Eventually, we provide a few recommendations for disease management, particularly in regions like Saudi Arabia where consanguineous marriages increase the risk.
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Affiliation(s)
- Nahed N. Mahrous
- Department of Biological Sciences, College of Science, University of Hafr Al-Batin, Hafr Al-Batin 39524, Saudi Arabia;
| | - Yahya F. Jamous
- The National Center of Vaccines and Bioprocessing, King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia;
| | - Ahmad M. Almatrafi
- Department of Biological Sciences, College of Science, Taibah University, Madinah 42353, Saudi Arabia;
| | - Deema I. Fallatah
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia;
| | - Abdulrahman Theyab
- Department of Laboratory and Blood Bank, Security Forces Hospital, Makkah 11481, Saudi Arabia;
- Department of Biochemistry & Molecular Medicine, College of Medicine, Al-Faisal University, P.O. Box 50927, Riyadh 11533, Saudi Arabia
| | - Bayan H. Alanati
- Center for Synthetic Microbiology, Bioinformatics Core Facility, University of Marburg, 35032 Marburg, Germany;
| | - Suliman A. Alsagaby
- Department of Medicinal Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah 11952, Saudi Arabia;
| | - Munifa K. Alenazi
- Research Center, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah 21499, Saudi Arabia; (M.K.A.); (M.I.K.)
| | - Mohammed I. Khan
- Research Center, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah 21499, Saudi Arabia; (M.K.A.); (M.I.K.)
| | - Yousef M. Hawsawi
- Department of Biochemistry & Molecular Medicine, College of Medicine, Al-Faisal University, P.O. Box 50927, Riyadh 11533, Saudi Arabia
- Research Center, King Faisal Specialist Hospital and Research Center, P.O. Box 40047, Jeddah 21499, Saudi Arabia; (M.K.A.); (M.I.K.)
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Ning L, Suleiman HY, Miner JH. Synaptopodin deficiency exacerbates kidney disease in a mouse model of Alport syndrome. Am J Physiol Renal Physiol 2021; 321:F12-F25. [PMID: 34029143 DOI: 10.1152/ajprenal.00035.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Synaptopodin (Synpo) is an actin-associated protein in podocyte foot processes. By generating mice that completely lack Synpo, we previously showed that Synpo is dispensable for normal kidney function. However, lack of Synpo worsened adriamycin-induced nephropathy, indicating a protective role for Synpo in injured podocytes. Here, we investigated whether lack of Synpo directly impacts a genetic disease, Alport syndrome (AS), because Synpo is reduced in podocytes of affected humans and mice; whether this is merely an association or pathogenic is unknown. We used collagen type IV-α5 (Col4a5) mutant mice, which model X-linked AS, showing glomerular basement membrane (GBM) abnormalities, eventual foot process effacement, and progression to end-stage kidney disease. We intercrossed mice carrying mutations in Synpo and Col4a5 to produce double-mutant mice. Urine and tissue were taken at select time points to evaluate albuminuria, histopathology, and glomerular capillary wall composition and ultrastructure. Lack of Synpo in Col4a5-/Y, Col4a5-/-, or Col4a5+/- Alport mice led to the acceleration of disease progression, including more severe proteinuria and glomerulosclerosis. Absence of Synpo attenuated the shift of myosin IIA from the podocyte cell body and major processes to actin cables near the GBM in the areas of effacement. We speculate that this is mechanistically associated with enhanced loss of podocytes due to easier detachment from the GBM. We conclude that Synpo deletion exacerbates the disease phenotype in Alport mice, revealing the podocyte actin cytoskeleton as a target for therapy in patients with AS.NEW & NOTEWORTHY Alport syndrome (AS) is a hereditary disease of the glomerular basement with hematuria and proteinuria. Podocytes eventually exhibit foot process effacement, indicating actin cytoskeletal changes. To investigate how cytoskeletal changes impact podocytes, we generated Alport mice lacking synaptopodin, an actin-binding protein in foot processes. Analysis showed a more rapid disease progression, demonstrating that synaptopodin is protective. This suggests that the actin cytoskeleton is a target for therapy in AS and perhaps other glomerular diseases.
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Affiliation(s)
- Liang Ning
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Hani Y Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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Ozdemir G, Gulhan B, Atayar E, Saygılı S, Soylemezoglu O, Ozcakar ZB, Eroglu FK, Candan C, Demir BK, Soylu A, Yüksel S, Alpay H, Agbas A, Duzova A, Hayran M, Ozaltin F, Topaloglu R. COL4A3 mutation is an independent risk factor for poor prognosis in children with Alport syndrome. Pediatr Nephrol 2020; 35:1941-1952. [PMID: 32394188 DOI: 10.1007/s00467-020-04574-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND Alport syndrome (AS) is an inherited glomerular disease caused by mutations in COL4A3, COL4A4, or COL4A5. Associations between clinical manifestations and genotype are not yet well defined. Our study aimed to define clinical and genetic characteristics, establish genotype-phenotype correlations, and determine prognosis of AS in children. METHODS A total of 87 children with AS from 10 pediatric nephrology centers, whom had genetic analyses performed at the Hacettepe University Nephrogenetics Laboratory between February 2017 and February 2019, were included. Data regarding demographics, family history, clinical and laboratory characteristics, histopathological and genetic test results, treatments, and yearly follow-up results were retrospectively analyzed. RESULTS Of 87 patients, 16% presented with nephrotic syndrome. In patients with nephrotic syndrome, kidney biopsy findings showed focal segmental glomerulosclerosis (FSGS) in 79%, and COL4A3 mutations were the leading genetic abnormality (50%). Twenty-four percent of all patients progressed to chronic kidney disease (CKD). The rate of progression to CKD and the decline in the glomerular filtration rate of the patients with COL4A3 mutation were higher than other mutation groups (p < 0.001 and p = 0.04, respectively). In kidney survival analysis, nephrotic syndrome presentation, histopathology of FSGS, COL4A3 mutations, and autosomal recessive inheritance were found as independent risk factors for earlier progression to CKD. Cyclosporin A treatment did not improve kidney survival. CONCLUSIONS We emphasize that genetic testing is important for patients suspected as having AS. Furthermore, COL4A mutations should be considered in patients with FSGS and steroid-resistant nephrotic syndrome. This approach will shed light on the prognosis of patients and help with definitive diagnosis, preventing unnecessary and potentially harmful medications. Graphical abstract.
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Affiliation(s)
- Gulsah Ozdemir
- Division of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, 06230, Ankara, Turkey
| | - Bora Gulhan
- Division of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, 06230, Ankara, Turkey
| | - Emine Atayar
- Division of Pediatric Nephrology, Nephrogenetics Laboratory, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Seha Saygılı
- Division of Pediatric Nephrology, Faculty of Medicine, Istanbul University-Cerrahpaşa, Istanbul, Turkey
| | - Oguz Soylemezoglu
- Division of Pediatric Nephrology, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Zeynep Birsin Ozcakar
- Division of Pediatric Nephrology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Fehime Kara Eroglu
- Division of Pediatric Nephrology, Dr. Sami Ulus Maternity and Children's Health Hospital, Ankara, Turkey
| | - Cengiz Candan
- Division of Pediatric Nephrology, Göztepe Training and Research Hospital, Istanbul Medeniyet University, Istanbul, Turkey
| | - Belde Kasap Demir
- Division of Pediatric Nephrology, Tepecik Training and Research Hospital, Izmir, Turkey
| | - Alper Soylu
- Division of Pediatric Nephrology, Faculty of Medicine, Dokuz Eylül University, Izmir, Turkey
| | - Selçuk Yüksel
- Division of Pediatric Nephrology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - Harika Alpay
- Division of Pediatric Nephrology, Faculty of Medicine, Marmara University, Istanbul, Turkey
| | - Ayse Agbas
- Division of Pediatric Nephrology, Haseki Training and Research Hospital, Istanbul, Turkey
| | - Ali Duzova
- Division of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, 06230, Ankara, Turkey
| | - Mutlu Hayran
- Department of Preventive Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Fatih Ozaltin
- Division of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, 06230, Ankara, Turkey.,Division of Pediatric Nephrology, Nephrogenetics Laboratory, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Rezan Topaloglu
- Division of Pediatric Nephrology, Faculty of Medicine, Hacettepe University, 06230, Ankara, Turkey.
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Williams VR, Konvalinka A, Song X, Zhou X, John R, Pei Y, Scholey JW. Connectivity mapping of a chronic kidney disease progression signature identified lysine deacetylases as novel therapeutic targets. Kidney Int 2020; 98:116-132. [PMID: 32418621 DOI: 10.1016/j.kint.2020.01.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 01/03/2020] [Accepted: 01/09/2020] [Indexed: 12/25/2022]
Abstract
Tubulointerstitial injury is an important determinant of chronic kidney disease progression, yet treatment is limited. Accordingly, we derived a chronic kidney disease progression signature based on aging and disease in Col4a3-/- mice, a model associated with proteinuria and progressive loss of kidney function. Computational drug repurposing with the Connectivity Map identified vorinostat, a lysine deacetylase inhibitor, as a candidate treatment to reverse progression signature gene expression. Vorinostat administration significantly increased the lifespan of Col4a3-/- mice and attenuated tubulointerstitial fibrosis and JNK phosphorylation in the kidneys of Col4a3-/- mice. In vitro, vorinostat reduced albumin- and angiotensin II-induced activation of canonical mitogen-activated protein kinases in kidney tubular epithelial cells. Finally, a subset of murine progression signature genes was differentially expressed across kidney transcriptomic data from patients with focal segmental glomerulosclerosis, IgA nephropathy, and diabetic nephropathy. Thus, our findings suggest that lysine deacetylase inhibition may be a novel treatment to chronic kidney disease associated with proteinuria and progressive tubulointerstitial injury.
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Affiliation(s)
| | - Ana Konvalinka
- Institute of Medical Science, University of Toronto, Toronto, Canada; Toronto General Hospital Research Institute, University Health Network, Toronto, Canada; Division of Nephrology, University Health Network, Toronto, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Xuewen Song
- Division of Nephrology, University Health Network, Toronto, Canada
| | - Xiaohua Zhou
- Institute of Medical Science, University of Toronto, Toronto, Canada
| | - Rohan John
- Toronto General Hospital Research Institute, University Health Network, Toronto, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada; Department of Pathology, University Health Network, Toronto, Canada
| | - York Pei
- Institute of Medical Science, University of Toronto, Toronto, Canada; Toronto General Hospital Research Institute, University Health Network, Toronto, Canada; Division of Nephrology, University Health Network, Toronto, Canada
| | - James W Scholey
- Institute of Medical Science, University of Toronto, Toronto, Canada; Toronto General Hospital Research Institute, University Health Network, Toronto, Canada; Division of Nephrology, University Health Network, Toronto, Canada; Department of Physiology, University of Toronto, Toronto, Canada
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van Roeyen CRC, Martin IV, Drescher A, Schuett KA, Hermert D, Raffetseder U, Otten S, Buhl EM, Braun GS, Kuppe C, Liehn E, Boor P, Weiskirchen R, Eriksson U, Gross O, Eitner F, Floege J, Ostendorf T. Identification of platelet-derived growth factor C as a mediator of both renal fibrosis and hypertension. Kidney Int 2019; 95:1103-1119. [PMID: 30827511 DOI: 10.1016/j.kint.2018.11.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 11/15/2018] [Accepted: 11/21/2018] [Indexed: 02/06/2023]
Abstract
Platelet-derived growth factors (PDGF) have been implicated in kidney disease progression. We previously found that PDGF-C is upregulated at sites of renal fibrosis and that antagonism of PDGF-C reduces fibrosis in the unilateral ureteral obstruction model. We studied the role of PDGF-C in collagen 4A3-/- ("Alport") mice, a model of progressive renal fibrosis with greater relevance to human kidney disease. Alport mice were crossbred with PDGF-C-/- mice or administered a neutralizing PDGF-C antibody. Both PDGF-C deficiency and neutralization reduced serum creatinine and blood urea nitrogen levels and mitigated glomerular injury, renal fibrosis, and renal inflammation. Unexpectedly, systolic blood pressure was also reduced in both Alport and wild-type mice treated with a neutralizing PDGF-C antibody. Neutralization of PDGF-C reduced arterial wall thickness in the renal cortex of Alport mice. Aortic rings isolated from anti-PDGF-C-treated wildtype mice exhibited reduced tension and faster relaxation than those of untreated mice. In vitro, PDGF-C upregulated angiotensinogen in aortic tissue and in primary hepatocytes and induced nuclear factor κB (NFκB)/p65-binding to the angiotensinogen promoter in hepatocytes. Neutralization of PDGF-C suppressed transcript expression of angiotensinogen in Alport mice and angiotensin II receptor type 1 in Alport and wildtype mice. Finally, administration of neutralizing PDGF-C antibodies ameliorated angiotensin II-induced hypertension in healthy mice. Thus, in addition to its key role in mediating renal fibrosis, we identified PDGF-C as a mediator of hypertension via effects on renal vasculature and on the renin-angiotensin system. The contribution to both renal fibrosis and hypertension render PDGF-C an attractive target in progressive kidney disease.
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Affiliation(s)
- Claudia R C van Roeyen
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany.
| | - Ina V Martin
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Ana Drescher
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | | | - Daniela Hermert
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Ute Raffetseder
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Stephanie Otten
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Eva M Buhl
- Institute of Pathology, RWTH Aachen University, Aachen, Germany
| | - Gerald S Braun
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Christoph Kuppe
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Elisa Liehn
- Institute for Molecular Cardiovascular Research, RWTH Aachen University, Aachen, Germany
| | - Peter Boor
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany; Institute of Pathology, RWTH Aachen University, Aachen, Germany
| | - Ralf Weiskirchen
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry RWTH Aachen University, Aachen, Germany
| | - Ulf Eriksson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Oliver Gross
- Division of Nephrology and Rheumatology, University Medicine Göttingen, Göttingen, Germany
| | - Frank Eitner
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany; Kidney Diseases Research, Bayer AG, Wuppertal, Germany
| | - Jürgen Floege
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Tammo Ostendorf
- Division of Nephrology and Clinical Immunology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
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Yokota T, Omachi K, Suico MA, Kojima H, Kamura M, Teramoto K, Kaseda S, Kuwazuru J, Shuto T, Kai H. Bromide supplementation exacerbated the renal dysfunction, injury and fibrosis in a mouse model of Alport syndrome. PLoS One 2017; 12:e0183959. [PMID: 28873450 PMCID: PMC5584969 DOI: 10.1371/journal.pone.0183959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 08/15/2017] [Indexed: 11/18/2022] Open
Abstract
A seminal study recently demonstrated that bromide (Br-) has a critical function in the assembly of type IV collagen in basement membrane (BM), and suggested that Br- supplementation has therapeutic potential for BM diseases. Because salts of bromide (KBr and NaBr) have been used as antiepileptic drugs for several decades, repositioning of Br- for BM diseases is probable. However, the effects of Br- on glomerular basement membrane (GBM) disease such as Alport syndrome (AS) and its impact on the kidney are still unknown. In this study, we administered daily for 16 weeks 75 mg/kg or 250 mg/kg (within clinical dosage) NaBr or NaCl (control) via drinking water to 6-week-old AS mice (mouse model of X-linked AS). Treatment with 75 mg/kg NaBr had no effect on AS progression. Surprisingly, compared with 250 mg/kg NaCl, 250 mg/kg NaBr exacerbated the progressive proteinuria and increased the serum creatinine and blood urea nitrogen in AS mice. Histological analysis revealed that glomerular injury, renal inflammation and fibrosis were exacerbated in mice treated with 250 mg/kg NaBr compared with NaCl. The expressions of renal injury markers (Lcn2, Lysozyme), matrix metalloproteinase (Mmp-12), pro-inflammatory cytokines (Il-6, Il-8, Tnf-α, Il-1β) and pro-fibrotic genes (Tgf-β, Col1a1, α-Sma) were also exacerbated by 250 mg/kg NaBr treatment. Notably, the exacerbating effects of Br- were not observed in wild-type mice. These findings suggest that Br- supplementation needs to be carefully evaluated for real positive health benefits and for the absence of adverse side effects especially in GBM diseases such as AS.
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Affiliation(s)
- Tsubasa Yokota
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Kohei Omachi
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School “HIGO (Health Life science: Interdisciplinary and Glocal Oriented) Program”, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Mary Ann Suico
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Haruka Kojima
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Misato Kamura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School “HIGO (Health Life science: Interdisciplinary and Glocal Oriented) Program”, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Keisuke Teramoto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School “HIGO (Health Life science: Interdisciplinary and Glocal Oriented) Program”, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Shota Kaseda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School “HIGO (Health Life science: Interdisciplinary and Glocal Oriented) Program”, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Jun Kuwazuru
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Tsuyoshi Shuto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
| | - Hirofumi Kai
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School “HIGO (Health Life science: Interdisciplinary and Glocal Oriented) Program”, Kumamoto University, 5–1 Oe-honmachi, Chuo-ku, Kumamoto City, Kumamoto, Japan
- * E-mail:
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Yokota T, Omachi K, Suico MA, Kamura M, Kojima H, Fukuda R, Motomura K, Teramoto K, Kaseda S, Kuwazuru J, Takeo T, Nakagata N, Shuto T, Kai H. STAT3 inhibition attenuates the progressive phenotypes of Alport syndrome mouse model. Nephrol Dial Transplant 2017; 33:214-223. [DOI: 10.1093/ndt/gfx246] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 06/26/2017] [Indexed: 11/12/2022] Open
Affiliation(s)
- Tsubasa Yokota
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Kohei Omachi
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School Health Life Science: Interdisciplinary and Glocal Oriented Program, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Mary Ann Suico
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Misato Kamura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School Health Life Science: Interdisciplinary and Glocal Oriented Program, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Haruka Kojima
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Ryosuke Fukuda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Keishi Motomura
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Keisuke Teramoto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School Health Life Science: Interdisciplinary and Glocal Oriented Program, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Shota Kaseda
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School Health Life Science: Interdisciplinary and Glocal Oriented Program, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Jun Kuwazuru
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Toru Takeo
- Division of Reproductive Engineering, Center for Animal Resources and Development, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Naomi Nakagata
- Division of Reproductive Engineering, Center for Animal Resources and Development, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Tsuyoshi Shuto
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
| | - Hirofumi Kai
- Department of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan
- Program for Leading Graduate School Health Life Science: Interdisciplinary and Glocal Oriented Program, Kumamoto University, Kumamoto City, Kumamoto, Japan
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Murine recombinant angiotensin-converting enzyme 2 attenuates kidney injury in experimental Alport syndrome. Kidney Int 2017; 91:1347-1361. [DOI: 10.1016/j.kint.2016.12.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 01/11/2023]
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Savva I, Pierides A, Deltas C. RAAS inhibition and the course of Alport syndrome. Pharmacol Res 2016; 107:205-210. [PMID: 26995302 DOI: 10.1016/j.phrs.2016.03.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/04/2016] [Accepted: 03/14/2016] [Indexed: 12/26/2022]
Abstract
Alport syndrome (AS) is a hereditary progressive glomerulonephritis with a high life-time risk for end-stage renal disease (ESRD). Most patients will reach ESRD before the age of 30 years, while a subset of them with milder mutations will do so at older ages, even after 50 years. Frequent extrarenal manifestations are hearing loss and ocular abnormalities. AS is a genetically heterogeneous collagen IV nephropathy, with 85% of the cases caused by mutations in the X-linked COL4A5 gene and the rest by homozygous or compound heterozygous mutations in either the COL4A3 or the COL4A4 gene on chromosome 2q36-37. There is no radical cure for the disease and attempts to use various stem cell therapies in animal models have been met with ambiguous success. However, effective treatment has been accomplished with pharmacological intervention at the renin-angiotensin-aldosterone system (RAAS), first in animal models of AS and more recently in humans. Angiotensin converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) have been shown to significantly delay the progression of chronic kidney disease and the onset of ESRD. Also, renin inhibitors and aldosterone blockade were used with positive results, while the combination of ACEis and ARBs was met with mixed success. An important study, the EARLY-PROTECT, aims at evaluating the efficacy of ACEis when administered very early on in children with AS. Novel therapies are also tested experimentally or are under design in animal models by several groups, including the use of amniotic fluid stem cells and synthetic chaperones.
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Affiliation(s)
- Isavella Savva
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Cyprus
| | - Alkis Pierides
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Cyprus; Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus
| | - Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Cyprus.
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Chen S, Grover M, Sibai T, Black J, Rianon N, Rajagopal A, Munivez E, Bertin T, Dawson B, Chen Y, Jiang MM, Lee B, Yang T, Bae Y. Losartan increases bone mass and accelerates chondrocyte hypertrophy in developing skeleton. Mol Genet Metab 2015; 115:53-60. [PMID: 25779879 PMCID: PMC4426054 DOI: 10.1016/j.ymgme.2015.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/20/2015] [Accepted: 02/21/2015] [Indexed: 10/23/2022]
Abstract
Angiotensin receptor blockers (ARBs) are a group of anti-hypertensive drugs that are widely used to treat pediatric hypertension. Recent application of ARBs to treat diseases such as Marfan syndrome or Alport syndrome has shown positive outcomes in animal and human studies, suggesting a broader therapeutic potential for this class of drugs. Multiple studies have reported a benefit of ARBs on adult bone homeostasis; however, its effect on the growing skeleton in children is unknown. We investigated the effect of Losartan, an ARB, in regulating bone mass and cartilage during development in mice. Wild type mice were treated with Losartan from birth until 6 weeks of age, after which bones were collected for microCT and histomorphometric analyses. Losartan increased trabecular bone volume vs. tissue volume (a 98% increase) and cortical thickness (a 9% increase) in 6-weeks old wild type mice. The bone changes were attributed to decreased osteoclastogenesis as demonstrated by reduced osteoclast number per bone surface in vivo and suppressed osteoclast differentiation in vitro. At the molecular level, Angiotensin II-induced ERK1/2 phosphorylation in RAW cells was attenuated by Losartan. Similarly, RANKL-induced ERK1/2 phosphorylation was suppressed by Losartan, suggesting a convergence of RANKL and angiotensin signaling at the level of ERK1/2 regulation. To assess the effect of Losartan on cartilage development, we examined the cartilage phenotype of wild type mice treated with Losartan in utero from conception to 1 day of age. Growth plates of these mice showed an elongated hypertrophic chondrocyte zone and increased Col10a1 expression level, with minimal changes in chondrocyte proliferation. Altogether, inhibition of the angiotensin pathway by Losartan increases bone mass and accelerates chondrocyte hypertrophy in growth plate during skeletal development.
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Affiliation(s)
- Shan Chen
- Department of Biostatistics, University of Texas Health Science Center at Houston School of Public Health
| | - Monica Grover
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Tarek Sibai
- Boston University School of Medicine Orthopedic Surgery, Boston University, Boston, MA, USA
| | - Jennifer Black
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, USA
| | - Nahid Rianon
- Department of Internal Medicine, University of Texas Medical School at Houston, TX, USA
| | - Abbhirami Rajagopal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Elda Munivez
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Terry Bertin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Brian Dawson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Yuqing Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ming-Ming Jiang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Tao Yang
- Laboratory of Skeletal Biology, Center for Skeletal Disease and Tumor Metastasis, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Yangjin Bae
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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11
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Ortiz A, Sanchez-Niño MD, Izquierdo MC, Martin-Cleary C, Garcia-Bermejo L, Moreno JA, Ruiz-Ortega M, Draibe J, Cruzado JM, Garcia-Gonzalez MA, Lopez-Novoa JM, Soler MJ, Sanz AB. Translational value of animal models of kidney failure. Eur J Pharmacol 2015; 759:205-20. [PMID: 25814248 DOI: 10.1016/j.ejphar.2015.03.026] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/08/2015] [Accepted: 03/12/2015] [Indexed: 11/28/2022]
Abstract
Acute kidney injury (AKI) and chronic kidney disease (CKD) are associated with decreased renal function and increased mortality risk, while the therapeutic armamentarium is unsatisfactory. The availability of adequate animal models may speed up the discovery of biomarkers for disease staging and therapy individualization as well as design and testing of novel therapeutic strategies. Some longstanding animal models have failed to result in therapeutic advances in the clinical setting, such as kidney ischemia-reperfusion injury and diabetic nephropathy models. In this regard, most models for diabetic nephropathy are unsatisfactory in that they do not evolve to renal failure. Satisfactory models for additional nephropathies are needed. These include anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, IgA nephropathy, anti-phospholipase-A2-receptor (PLA2R) membranous nephropathy and Fabry nephropathy. However, recent novel models hold promise for clinical translation. Thus, the AKI to CKD translation has been modeled, in some cases with toxins of interest for human CKD such as aristolochic acid. Genetically modified mice provide models for Alport syndrome evolving to renal failure that have resulted in clinical recommendations, polycystic kidney disease models that have provided clues for the development of tolvaptan, that was recently approved for the human disease in Japan; and animal models also contributed to target C5 with eculizumab in hemolytic uremic syndrome. Some ongoing trials explore novel concepts derived from models, such TWEAK targeting as tissue protection for lupus nephritis. We now review animal models reproducing diverse, genetic and acquired, causes of AKI and CKD evolving to kidney failure and discuss the contribution to clinical translation and prospects for the future.
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Affiliation(s)
- Alberto Ortiz
- Nephrology, IIS-Fundacion Jimenez Diaz, Madrid, Spain; REDinREN, Madrid, Spain; Universidad Autonoma de Madrid, Madrid, Spain; IRSIN, Madrid, Spain
| | | | - Maria C Izquierdo
- Nephrology, IIS-Fundacion Jimenez Diaz, Madrid, Spain; REDinREN, Madrid, Spain
| | | | - Laura Garcia-Bermejo
- REDinREN, Madrid, Spain; Dpt. of Pathology, Instituto Ramón y Cajal de Investigación Sanitaria, IRYCIS, Madrid, Spain
| | - Juan A Moreno
- Nephrology, IIS-Fundacion Jimenez Diaz, Madrid, Spain
| | - Marta Ruiz-Ortega
- Nephrology, IIS-Fundacion Jimenez Diaz, Madrid, Spain; REDinREN, Madrid, Spain; Universidad Autonoma de Madrid, Madrid, Spain
| | - Juliana Draibe
- REDinREN, Madrid, Spain; Nephrology Department, Hospital Universitari de Bellvitge, IDIBELL, L׳Hospitalet de Llobregat, Barcelona, Spain
| | - Josep M Cruzado
- REDinREN, Madrid, Spain; Nephrology Department, Hospital Universitari de Bellvitge, IDIBELL, L׳Hospitalet de Llobregat, Barcelona, Spain
| | - Miguel A Garcia-Gonzalez
- REDinREN, Madrid, Spain; Laboratorio de Nefrología, Complexo Hospitalario de Santiago de Compostela (CHUS), Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - Jose M Lopez-Novoa
- REDinREN, Madrid, Spain; Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamnca, Spain
| | - Maria J Soler
- REDinREN, Madrid, Spain; Nephrology Department, Hospital del Mar, Barcelona, Spain
| | - Ana B Sanz
- Nephrology, IIS-Fundacion Jimenez Diaz, Madrid, Spain; REDinREN, Madrid, Spain.
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12
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Borza CM, Chen X, Zent R, Pozzi A. Cell Receptor-Basement Membrane Interactions in Health and Disease: A Kidney-Centric View. CURRENT TOPICS IN MEMBRANES 2015; 76:231-53. [PMID: 26610916 PMCID: PMC4913201 DOI: 10.1016/bs.ctm.2015.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell-extracellular matrix (ECM) interactions are essential for tissue development, homeostasis, and response to injury. Basement membranes (BMs) are specialized ECMs that separate epithelial or endothelial cells from stromal components and interact with cells via cellular receptors, including integrins and discoidin domain receptors. Disruption of cell-BM interactions due to either injury or genetic defects in either the ECM components or cellular receptors often lead to irreversible tissue injury and loss of organ function. Animal models that lack specific BM components or receptors either globally or in selective tissues have been used to help with our understanding of the molecular mechanisms whereby cell-BM interactions regulate organ function in physiological and pathological conditions. We review recently published works on animal models that explore how cell-BM interactions regulate kidney homeostasis in both health and disease.
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Affiliation(s)
- Corina M. Borza
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, 37232
| | - Xiwu Chen
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
| | - Roy Zent
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Medicine, Veterans Administration Hospital, Nashville, TN, 37232
| | - Ambra Pozzi
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, 37232
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN, 37232
- Department of Medicine, Veterans Administration Hospital, Nashville, TN, 37232
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13
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Ahmed R, Duerr U, Gavenis K, Hilgers R, Gross O. Challenges for academic investigator-initiated pediatric trials for rare diseases. Clin Ther 2014; 36:184-90. [PMID: 24529291 DOI: 10.1016/j.clinthera.2014.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/16/2014] [Accepted: 01/16/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Clinical trials require great effort, time, expertise, and money. For clinicians at university hospitals with their full work load of teaching and medical care, the planning of an investigator-initiated clinical trial seems almost unthinkable. Despite their expertise in distinct diseases, university clinicians lack the time necessary to organize the funding and to initiate and conduct Phase III clinical trials in adults or in children. OBJECTIVE We sought to determine whether the difficulties faced by a clinician conducting a pediatric clinical trial can be overcome by passionate motivation and external support. METHODS Critical aspects of the application process of the world's first clinical trial in children with the rare hereditary kidney disease Alport syndrome treated with an angiotensin-converting enzyme inhibitor (Early Prospective Therapy Trial to Delay Renal Failure in Children With Alport Syndrome [EARLY PRO-TECT Alport]; http://www.clinicaltrials.gov NCT01485978; EudraCT 2010-024300-10) are described. RESULTS The following crucial factors enabled the investigator to complete this trial: (1) support through clinical trial, biometrician, and regulatory experts (Institute for Applied Research and Clinical Studies [IFS], Göttingen, Germany); (2) advice from the university's ethics committee (University Medicine Göttingen, Göttingen, Germany); (3) public funding (€1 million from the German Federal Ministry of Education and Research); (4) support from the respective medical society, aiming at the resolution of an important clinical problem (German Society of Pediatric Nephrology); and (5) support from the investigator's university as the official sponsor of the trial, providing long-term commitment and covering financial risks (University Medical Center Göttingen, Göttingen, Germany). CONCLUSIONS The study could pave the way for approval of ramipril as a drug to treat children with Alport syndrome. Even though the study might not result in label changes, the EARLY PRO-TECT Alport trial provides the basis of an educational campaign to sensitize physicians, especially pediatricians, general practitioners, and nephrologists, to pay special attention to the early detection of kidney diseases in children, which could improve medical care for all children with kidney diseases.
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Affiliation(s)
- Raees Ahmed
- Institute for Applied Research and Clinical Trials GmbH, Georg August University Göttingen, Göttingen, Germany; Institute for Applied Research and Clinical Trials GmbH, Georg August University Göttingen, Göttingen, Germany
| | - Ulrike Duerr
- Institute for Applied Research and Clinical Trials GmbH, Georg August University Göttingen, Göttingen, Germany; Institute for Applied Research and Clinical Trials GmbH, Georg August University Göttingen, Göttingen, Germany
| | - Karsten Gavenis
- Institute for Applied Research and Clinical Trials GmbH, Georg August University Göttingen, Göttingen, Germany
| | - Reinhard Hilgers
- University Medical Center Göttingen, Institute of Medical Statistics, Göttingen, Germany
| | - Oliver Gross
- University Medical Center Göttingen, Clinic for Nephrology and Rheumatology, Göttingen, Germany.
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14
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Xiu X, Yuan J, Deng X, Xiao J, Xu H, Zeng Z, Guan L, Xu F, Deng S. A novel COL4A5 mutation identified in a Chinese Han family using exome sequencing. BIOMED RESEARCH INTERNATIONAL 2014; 2014:186048. [PMID: 25110662 PMCID: PMC4109303 DOI: 10.1155/2014/186048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/20/2014] [Indexed: 11/17/2022]
Abstract
Alport syndrome (AS) is a monogenic disease of the basement membrane (BM), resulting in progressive renal failure due to glomerulonephropathy, variable sensorineural hearing loss, and ocular anomalies. It is caused by mutations in the collagen type IV alpha-3 gene (COL4A3), the collagen type IV alpha-4 gene (COL4A4), and the collagen type IV alpha-5 gene (COL4A5), which encodes type IV collagen α3, α4, and α5 chains, respectively. To explore the disease-related gene in a four-generation Chinese Han pedigree of AS, exome sequencing was conducted on the proband, and a novel deletion mutation c.499delC (p.Pro167Glnfs*36) in the COL4A5 gene was identified. This mutation, absent in 1,000 genomes project, HapMap, dbSNP132, YH1 databases, and 100 normal controls, cosegregated with patients in the family. Neither sensorineural hearing loss nor typical COL4A5-related ocular abnormalities (dot-and-fleck retinopathy, anterior lenticonus, and the rare posterior polymorphous corneal dystrophy) were present in patients of this family. The phenotypes of patients in this AS family were characterized by early onset-age and rapidly developing into end-stage renal disease (ESRD). Our discovery broadens the mutation spectrum in the COL4A5 gene associated with AS, which may also shed new light on genetic counseling for AS.
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Affiliation(s)
- Xiaofei Xiu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
- Department of Pharmacy, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, Hunan 410008, China
| | - Jinzhong Yuan
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Xiong Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | | | - Hongbo Xu
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
| | - Zhaoyang Zeng
- Cancer Research Institute, Xiangya Medical School of Central South University, Changsha, Hunan 410008, China
| | - Liping Guan
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Fengping Xu
- BGI-Shenzhen, Shenzhen, Guangdong 518083, China
| | - Sheng Deng
- Center for Experimental Medicine and Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
- Department of Pharmacy, Xiangya Hospital, Central South University, Xiangya Road 87, Kaifu District, Changsha, Hunan 410008, China
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15
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Werk AN, Lefeldt S, Bruckmueller H, Hemmrich-Stanisak G, Franke A, Roos M, Küchle C, Steubl D, Schmaderer C, Bräsen JH, Heemann U, Cascorbi I, Renders L. Identification and characterization of a defective CYP3A4 genotype in a kidney transplant patient with severely diminished tacrolimus clearance. Clin Pharmacol Ther 2013; 95:416-22. [PMID: 24126681 DOI: 10.1038/clpt.2013.210] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 10/02/2013] [Indexed: 11/09/2022]
Abstract
Cytochrome P450 3A4 (CYP3A4) is a major drug-metabolizing enzyme that is widely investigated. So far, no homozygous inactive variant has been described. We report on a 19-year-old kidney transplant patient suffering from Alport syndrome, who experienced unexpected high tacrolimus plasma trough levels during immunosuppressant therapy. Because nonadherence, liver failure, or drug-drug interactions could be excluded, we hypothesized a diminished metabolism of the drug caused by mutations in the main detoxification enzyme, CYP3A4. Exome sequencing revealed a novel single-nucleotide polymorphism (c.802C>T) resulting in a premature stop codon in CYP3A4 exon 5. Accordingly, no CYP3A4 protein could be detected in kidney biopsy tissue, and there was lack of expression in HepG2 cells transiently transfected with the mutated CYP3A4. In addition, the patient harbored inactive CYP3A5*3, resulting in loss of function of the entire CYP3A locus, explaining the deteriorated tacrolimus clearance. This is, to our knowledge, the first case of a complete failure of CYP3A4 in humans.
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Affiliation(s)
- A N Werk
- Institute for Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - S Lefeldt
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
| | - H Bruckmueller
- Institute for Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - G Hemmrich-Stanisak
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - A Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - M Roos
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
| | - C Küchle
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
| | - D Steubl
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
| | - C Schmaderer
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
| | - J H Bräsen
- 1] Institute of Pathology Hamburg-West, Hamburg, Germany [2] Institute for Pathology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - U Heemann
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
| | - I Cascorbi
- Institute for Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - L Renders
- Department of Nephrology, University Hospital Klinikum rechts der Isar of the Technical University of Munich, Munich, Germany
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16
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Giani M, Mastrangelo A, Villa R, Turolo S, Marra G, Tirelli AS, Hopfer H, Edefonti A. Alport syndrome: the effects of spironolactone on proteinuria and urinary TGF-β1. Pediatr Nephrol 2013; 28:1837-42. [PMID: 23748277 DOI: 10.1007/s00467-013-2490-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/16/2013] [Accepted: 04/09/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Alport syndrome (AS) is a progressive hereditary glomerular disease. Recent data indicate that aldosterone promotes fibrosis mediated by the transforming growth factor-β1 (TGF-β1) pathway, which may worsen proteinuria. Spironolactone (SP) antagonizes aldosterone and this study aimed to evaluate the efficacy of SP in reducing proteinuria and urinary TGF-β1 excretion in proteinuric AS patients. METHODS The study involved ten children with AS, normal renal function, and persistent proteinuria (>6 months; uPr/uCr ratio >1). SP 25 mg once a day for 6 months was added to existing ACE inhibitor treatment with or without angiotensin-II receptor blockade. Urine and blood samples were examined monthly. Urinary TGF-β1 levels were measured twice before and three times during SP treatment. Plasma renin activity (PRA) and serum aldosterone levels were also measured. In eight patients, uProt/uCreat was also assessed after 9 months and 12 months of SP treatment. RESULTS After beginning SP therapy, all patients showed significant decrease in mean uProt/uCreat ratio (1.77 ± 0.8 to 0.86 ± 0.6; p < 0.001) and mean urinary TGF-β1 levels (104 ± 54 to 41 ± 20 pg/mgCreatinine; p < 0.01), beginning after 30 days of treatment and remaining stable throughout SP administration. PRA remain unchanged, and mean serum aldosterone increased from 105 ± 72 pg/ml to 303 ± 156 pg/ml (p < 0.001). The only side effect was gynecomastia in an obese boy. After 1 year of therapy, mean uProt/uCreat remains low (0.82 ± 0.48). CONCLUSIONS Addition of SP to ACE-I treatment with or without angiotensin II receptor blokers (ARB) significantly reduced proteinuria. This was mediated by decreased urinary TGF-β1 levels and not associated with major side effects.
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Affiliation(s)
- Marisa Giani
- Pediatric Nephrology and Dialysis Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via della Commenda 9, 20122, Milan, Italy
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Gyoneva L, Segal Y, Dorfman KD, Barocas VH. Mechanical response of wild-type and Alport murine lens capsules during osmotic swelling. Exp Eye Res 2013; 113:87-91. [PMID: 23707242 DOI: 10.1016/j.exer.2013.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 05/06/2013] [Accepted: 05/13/2013] [Indexed: 01/05/2023]
Abstract
The mechanical support of basement membranes, such as the lens capsule, is believed to arise from one of their main constituents - collagen IV. The basement membranes of the lens, kidney, and ear normally contain two different types of collagen IV networks, referred to as the major and minor chain networks. In Alport syndrome, a mutation in one of the minor chain COL4 genes leads to the absence of the minor chain network, causing life-threatening disturbances. We hypothesized that the absence of the minor chain network increases basement membrane distensibility, as measured in wild-type (n = 25) and Alport syndrome (n = 21) mice using the lens capsule as a model. Osmotic swelling experiments revealed direction-dependent changes. As a reflection of lens capsule properties, Alport lenses strained significantly more than wild-type lenses in the anterior-posterior direction, i.e. along their thickness, but not in the equatorial direction (p = 0.03 and p = 0.08, respectively). This is consistent with clinical data: Alport patients develop conical protrusions on the anterior and posterior lenticular poles. There was no evidence of significant change in total amount of collagen between Alport and wild-type lenses (p = 0.6). The observed differences in distensibility could indicate that the major chain network alone cannot fully compensate for the absence of the more highly cross-linked minor chain network, which is believed to be stronger, more stable, and resistant to deformation. The addition of mechanical information on Alport syndrome to the currently available biological data provides a fuller picture into the progression of the disease.
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Affiliation(s)
- Lazarina Gyoneva
- Department of Biomedical Engineering, University of Minnesota, 7-105 Nils Hasselmo Hall, 312 Church St. SE, Minneapolis, MN 55455, United States.
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18
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Webb NJA, Shahinfar S, Wells TG, Massaad R, Gleim GW, McCrary Sisk C, Lam C. Losartan and enalapril are comparable in reducing proteinuria in children with Alport syndrome. Pediatr Nephrol 2013. [PMID: 23207876 DOI: 10.1007/s00467-012-2372-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND A previous subgroup analysis of a 12-week, double-blind study demonstrated that losartan significantly lowered proteinuria versus placebo and amlodipine and was well tolerated in children (1-17 years old) with proteinuria secondary to Alport syndrome. The present subgroup analysis of the open-label, extension phase of this study assessed the long-term efficacy and tolerability of losartan versus enalapril. METHODS Patients who had completed the double-blind study were re-randomized to losartan or enalapril and followed for proteinuria and renal function for up to 3 years. RESULTS Twenty-seven patients with Alport syndrome were randomized to losartan (0.44-2.23 mg/kg/day; n = 15) or enalapril (0.07-0.72 mg/kg/day; n = 12). The least-squares (LS) mean percent change from week 12 in urinary protein to creatinine ratio (UPr/Cr was +1.1 % in the losartan group versus a further 13.9 % reduction in the enalapril group (GMR [95 % CI] = 1.2 [0.7, 2.0]); the LS mean change from week 12 in estimated glomerular filtration rate (eGFR) was -6.4 ml/min/1.73 m(2) in the losartan group versus -9.1 ml/min/1.73 m(2) in the enalapril group. The adverse event incidence was low and comparable in both treatment groups. CONCLUSIONS In children with proteinuria secondary to Alport syndrome, losartan maintained proteinuria reduction, and enalapril produced a further proteinuria reduction over the 3-year study period. Both agents were generally well tolerated.
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Affiliation(s)
- Nicholas J A Webb
- Department of Paediatric Nephrology and Wellcome Trust Children's Clinical Research Facility, Manchester Academic Health Science Centre, Royal Manchester Children's Hospital, The University of Manchester, Manchester, UK.
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Kashtan CE, Ding J, Gregory M, Gross O, Heidet L, Knebelmann B, Rheault M, Licht C. Clinical practice recommendations for the treatment of Alport syndrome: a statement of the Alport Syndrome Research Collaborative. Pediatr Nephrol 2013; 28:5-11. [PMID: 22461141 PMCID: PMC3505543 DOI: 10.1007/s00467-012-2138-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 01/29/2012] [Accepted: 01/31/2012] [Indexed: 12/21/2022]
Abstract
We present clinical practice recommendations for the treatment of children with Alport syndrome who are not enrolled in clinical trials. Our goal is to promote early initiation of a standard therapeutic approach that will facilitate assessment of the safety and efficacy of the protocol. The treatment protocol is based on the reduction of proteinuria, intraglomerular pressure, and renal fibrosis via interference with the renin-angiotensin-aldosterone system.
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Affiliation(s)
- Clifford E. Kashtan
- Department of Pediatrics, Division of Pediatric Nephrology, University of Minnesota Medical School, Minneapolis, MN USA
| | - Jie Ding
- Pediatric Department, Peking University First Hospital, Beijing, People’s Republic of China
| | - Martin Gregory
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT USA
| | - Oliver Gross
- Department of Nephrology and Rheumatology, University Medicine Goettingen, Goettingen, Germany
| | - Laurence Heidet
- Centre de référence pour les Maladies Rénales Héréditaires de l’Enfant et de l’Adulte (MARHEA) and Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants malades, Paris, France
| | - Bertrand Knebelmann
- Centre de référence pour les Maladies Rénales Héréditaires de l’Enfant et de l’Adulte (MARHEA) and Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants malades, Paris, France
| | - Michelle Rheault
- Department of Pediatrics, Division of Pediatric Nephrology, University of Minnesota Medical School, Minneapolis, MN USA
| | - Christoph Licht
- The Hospital for Sick Children, Division of Nephrology, Toronto, Canada
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Temme J, Kramer A, Jager KJ, Lange K, Peters F, Müller GA, Kramar R, Heaf JG, Finne P, Palsson R, Reisæter AV, Hoitsma AJ, Metcalfe W, Postorino M, Zurriaga O, Santos JP, Ravani P, Jarraya F, Verrina E, Dekker FW, Gross O. Outcomes of male patients with Alport syndrome undergoing renal replacement therapy. Clin J Am Soc Nephrol 2012; 7:1969-76. [PMID: 22997344 DOI: 10.2215/cjn.02190312] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Patients with the hereditary disease Alport syndrome commonly require renal replacement therapy (RRT) in the second or third decade of life. This study compared age at onset of RRT, renal allograft, and patient survival in men with Alport syndrome receiving various forms of RRT (peritoneal dialysis, hemodialysis, or transplantation) with those of men with other renal diseases. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Patients with Alport syndrome receiving RRT identified from 14 registries in Europe were matched to patients with other renal diseases. A linear spline model was used to detect changes in the age at start of RRT over time. Kaplan-Meier method and Cox regression analysis were used to examine patient and graft survival. RESULTS Age at start of RRT among patients with Alport syndrome remained stable during the 1990s but increased by 6 years between 2000-2004 and 2005-2009. Survival of patients with Alport syndrome requiring dialysis or transplantation did not change between 1990 and 2009. However, patients with Alport syndrome had better renal graft and patient survival than matched controls. Numbers of living-donor transplantations were lower in patients with Alport syndrome than in matched controls. CONCLUSIONS These data suggest that kidney failure in patients with Alport syndrome is now being delayed compared with previous decades. These patients appear to have superior patient survival while undergoing dialysis and superior patient and graft survival after deceased-donor kidney transplantation compared with patients receiving RRT because of other causes of kidney failure.
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Affiliation(s)
- Johanna Temme
- Dept Nephrology&Rheumatology, University Medical Center Göttingen, Göttingen, Germany
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Gross O, Friede T, Hilgers R, Görlitz A, Gavénis K, Ahmed R, Dürr U. Safety and Efficacy of the ACE-Inhibitor Ramipril in Alport Syndrome: The Double-Blind, Randomized, Placebo-Controlled, Multicenter Phase III EARLY PRO-TECT Alport Trial in Pediatric Patients. ISRN PEDIATRICS 2012; 2012:436046. [PMID: 22811928 PMCID: PMC3395192 DOI: 10.5402/2012/436046] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 04/11/2012] [Indexed: 01/27/2023]
Abstract
Introduction. Retrospective observational data show that ACE-inhibitor therapy delays renal failure and improves life expectancy in Alport patients with proteinuria. The EARLY PRO-TECT Alport trial assesses the safety and efficacy of early therapy onset with ramipril in pediatric Alport patients. Methods and analysis. This double-blind, randomized, placebo-controlled, multicenter phase III trial (NCT01485978; EudraCT-number 2010-024300-10) includes 120 pediatric patients aged 24 months to 18 years with early stages of Alport syndrome (isolated hematuria or microalbuminuria). From March 2012, up to 80 patients will be randomized 1:1 to ramipril or placebo. In the event of disease progression during 3-year treatment, patients are unblinded and ramipril is initiated, if applicable. Approximately 40 patients receive open-label ramipril contributing to the safety database. Primary end-points are “time to progression to next disease level” and “incidence of adverse drug events before disease progression.” Treatment effect estimates from the randomized comparison and Alport registry data will be combined in supportive analyses to maximize evidence. Conclusion. Without this trial, ACE inhibitors may become standard off-label treatment in Alport syndrome without satisfactory evidence base. The results are expected to be of relevance for therapy of all pediatric patients with kidney disease, and the trial protocol might serve as a model for other rare pediatric glomerulopathies.
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Affiliation(s)
- Oliver Gross
- Department of Nephrology and Rheumatology, University Medical Center Göttingen, Robert-Koch Stra β e 40, 37075 Göttingen, Germany
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Incidence of renal failure and nephroprotection by RAAS inhibition in heterozygous carriers of X-chromosomal and autosomal recessive Alport mutations. Kidney Int 2012; 81:779-83. [PMID: 22237748 DOI: 10.1038/ki.2011.452] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We studied here the clinical course of heterozygous carriers of X-linked Alport syndrome and a subgroup of patients with thin basement membrane disease due to heterozygous autosomal recessive Alport mutations whose prognosis may be worse than formerly thought. We analyzed 234 Alport carriers, including 29 with autosomal recessive mutations. Using Kaplan-Meier estimates and log-rank tests, autosomal and X-linked carriers were found to have similar incidences of renal replacement therapy, proteinuria, and impaired creatinine clearance. Further, age at onset of renal replacement therapy did not differ between X-chromosomal and autosomal carriers. Both groups showed an impaired life expectancy when reaching renal replacement therapy. RAAS inhibition significantly delayed the onset of end-stage renal failure. Not only carriers of X-linked Alport mutations but also heterozygous carriers of autosomal recessive mutations were found to have an increased risk for worse renal function. The risk of end-stage renal disease in both groups affected life expectancy, and this should cause a greater alertness toward patients presenting with what has been wrongly termed 'familial benign hematuria.' Timely therapy can help to delay onset of end-stage renal failure. Thus, yearly follow-up by a nephrologist is advised for X-linked Alport carriers and patients with thin basement membrane nephropathy, microalbuminuria, proteinuria, or hypertension.
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Early angiotensin-converting enzyme inhibition in Alport syndrome delays renal failure and improves life expectancy. Kidney Int 2011; 81:494-501. [PMID: 22166847 DOI: 10.1038/ki.2011.407] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Alport syndrome inevitably leads to end-stage renal disease and there are no therapies known to improve outcome. Here we determined whether angiotensin-converting enzyme inhibitors can delay time to dialysis and improve life expectancy in three generations of Alport families. Patients were categorized by renal function at the initiation of therapy and included 33 with hematuria or microalbuminuria, 115 with proteinuria, 26 with impaired renal function, and 109 untreated relatives. Patients were followed for a period whose mean duration exceeded two decades. Untreated relatives started dialysis at a median age of 22 years. Treatment of those with impaired renal function significantly delayed dialysis to a median age of 25, while treatment of those with proteinuria delayed dialysis to a median age of 40. Significantly, no patient with hematuria or microalbuminuria advanced to renal failure so far. Sibling pairs confirmed these results, showing that earlier therapy in younger patients significantly delayed dialysis by 13 years compared to later or no therapy in older siblings. Therapy significantly improved life expectancy beyond the median age of 55 years of the no-treatment cohort. Thus, Alport syndrome is treatable with angiotensin-converting enzyme inhibition to delay renal failure and therapy improves life expectancy in a time-dependent manner. This supports the need for early diagnosis and early nephroprotective therapy in oligosymptomatic patients.
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Vehaskari VM. Genetics and CKD. Adv Chronic Kidney Dis 2011; 18:317-23. [PMID: 21896372 DOI: 10.1053/j.ackd.2011.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 07/10/2011] [Accepted: 07/11/2011] [Indexed: 01/15/2023]
Abstract
The diagnosis of hereditary monogenic kidney diseases is frequently delayed, in part because of physicians' unfamiliarity with the relatively rare conditions or because of the late onset of symptoms in some patients. Molecular biology methods have clarified the underlying mutations in several types of CKD, and in the process have revealed previously unknown genes and pathogenetic pathways. Mutations affecting the integrity of the glomerular filtration barrier cause proteinuria or nephrotic syndrome; different types of Alport syndrome are caused by mutations in glomerular basement membrane type IV collagen; dysfunction of the primary cilium of tubule cells may lead to a variety of inherited progressive tubulointerstitial diseases; atypical hemolytic-uremic syndrome is frequently caused by inherited complement deficiencies; and progressive kidney injury develops in many inherited systemic or metabolic disorders. Some genetic diseases may not manifest until late childhood or adulthood. Accurate diagnosis is important for appropriate treatment, prognosis, genetic counseling, and possible renal transplantation.
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Mechanisms and consequences of TGF-ß overexpression by podocytes in progressive podocyte disease. Cell Tissue Res 2011; 347:129-40. [PMID: 21541658 PMCID: PMC3250617 DOI: 10.1007/s00441-011-1169-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 04/04/2011] [Indexed: 01/21/2023]
Abstract
In patients with progressive podocyte disease, such as focal segmental glomerulosclerosis (FSGS) and membranous nephropathy, upregulation of transforming growth factor-ß (TGF-ß) is observed in podocytes. Mechanical pressure or biomechanical strain in podocytopathies may cause overexpression of TGF-ß and angiotensin II (Ang II). Oxidative stress induced by Ang II may activate the latent TGF-ß, which then activates Smads and Ras/extracellular signal-regulated kinase (ERK) signaling pathways in podocytes. Enhanced TGF-ß activity in podocytes may lead to thickening of the glomerular basement membrane (GBM) by overproduction of GBM proteins and impaired GBM degradation in podocyte disease. It may also lead to podocyte apoptosis and detachment from the GBM, and epithelial-mesenchymal transition (EMT) of podocytes, initiating the development of glomerulosclerosis. Furthermore, activated TGF-ß/Smad signaling by podocytes may induce connective tissue growth factor and vascular endothelial growth factor overexpression, which could act as a paracrine effector mechanism on mesangial cells to stimulate mesangial matrix synthesis. In proliferative podocytopathies, such as cellular or collapsing FSGS, TGF-ß-induced ERK activation may play a role in podocyte proliferation, possibly via TGF-ß-induced EMT of podocytes. Collectively, these data bring new mechanistic insights into our understanding of the TGF-ß overexpression by podocytes in progressive podocyte disease.
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Webb NJA, Lam C, Shahinfar S, Strehlau J, Wells TG, Gleim GW, Le Bailly De Tilleghem C. Efficacy and safety of losartan in children with Alport syndrome--results from a subgroup analysis of a prospective, randomized, placebo- or amlodipine-controlled trial. Nephrol Dial Transplant 2011; 26:2521-6. [DOI: 10.1093/ndt/gfq797] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bassareo PP, Marras AR, Mercuro G. Ventricular septal defect in a child with Alport syndrome: a case report. BMC Cardiovasc Disord 2010; 10:48. [PMID: 20920374 PMCID: PMC2958932 DOI: 10.1186/1471-2261-10-48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 10/05/2010] [Indexed: 12/16/2022] Open
Abstract
Background Alport syndrome (AS) is a rare inherited disorder characterized by an inflammation of the kidneys and damage to the glomerular capillaries, ultimately leading to renal failure at an early age. To date, rare reports of cardiac involvement in AS have been described, due in the majority of cases to the higher risk of heart conduction abnormalities in these patients, at times requiring implantation of a transcutaneous pacemaker. An increased risk of hypertension is likewise commonly featured. Case presentation We report the case of a 17-year-old female affected by a very severe early form of AS. A previously unreported association of the syndrome with congenital heart disease (CHD), (in this case membranous ventricular septal defect), is also reported. A possible pathophysiological mechanism underlying the concomitant manifestation of these two disorders is suggested. Complications implicated in surgical treatment of CHD are described. Clinical and therapeutic management of AS with cardiovascular involvement are discussed, and a short literature review performed. Conclusions This first report of a cardiovascular association highlights the possible involvement of collagen mutations in the two pathologies. Even when drug-resistance appears to be responsible for the failure to control secondary hypertension in AS, clonidine may represent a safe, effective option in the normalization of high blood pressure.
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Affiliation(s)
- Pier Paolo Bassareo
- Department of Cardiovascular and Neurological Sciences, University of Cagliari, Cagliari, Italy.
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Kruegel J, Miosge N. Basement membrane components are key players in specialized extracellular matrices. Cell Mol Life Sci 2010; 67:2879-95. [PMID: 20428923 PMCID: PMC2921489 DOI: 10.1007/s00018-010-0367-x] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/17/2010] [Accepted: 03/24/2010] [Indexed: 01/11/2023]
Abstract
More than three decades ago, basement membranes (BMs) were described as membrane-like structures capable of isolating a cell from and connecting a cell to its environment. Since this time, it has been revealed that BMs are specialized extracellular matrices (sECMs) with unique components that support important functions including differentiation, proliferation, migration, and chemotaxis of cells during development. The composition of these sECM is as unique as the tissues to which they are localized, opening the possibility that such matrices can fulfill distinct functions. Changes in BM composition play significant roles in facilitating the development of various diseases. Furthermore, tissues have to provide sECM for their stem cells during development and for their adult life. Here, we briefly review the latest research on these unique sECM and their components with a special emphasis on embryonic and adult stem cells and their niches.
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Affiliation(s)
- Jenny Kruegel
- Tissue Regeneration Work Group, Department of Prosthodontics, Georg August University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Nicolai Miosge
- Tissue Regeneration Work Group, Department of Prosthodontics, Georg August University, Robert-Koch-Str. 40, 37075 Göttingen, Germany
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Massella L, Muda AO, Legato A, Di Zazzo G, Giannakakis K, Emma F. Cyclosporine A treatment in patients with Alport syndrome: a single-center experience. Pediatr Nephrol 2010; 25:1269-75. [PMID: 20238228 DOI: 10.1007/s00467-010-1484-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 01/06/2010] [Accepted: 01/27/2010] [Indexed: 11/30/2022]
Abstract
Limited and discordant data are available on cyclosporine A (CsA) treatment for proteinuria in Alport syndrome (AS). To address this lack of consistent data, we have studied 15 AS patients (14 males; mean age 15.3 +/- 6.0 years) treated with CsA. Patient selection criteria included a urinary protein/creatinine ratio > or =1 mg/mg and a creatinine clearance >40 ml/min/1.73 m(2). CsA treatment was started at an initial dose of 5 mg/kg/day and subsequently adjusted to reach target C2 levels of 500 ng/ml. Renal function, proteinuria, and blood pressure were monitored. Blood pressure was treated to avoid the administration of angiotensin converting enzyme or angiotensin receptor blockers for the first 2 years of therapy. The average follow-up was 3.5 years. Five patients had chronic renal failure at the beginning of treatment, of whom three and one reached end-stage renal failure within 1 and 3 years, respectively. In the remaining 11 patients, the glomerular filtration rate declined by 11 +/- 6% within 6 months, but remained stable thereafter. Proteinuria decreased by 63 +/- 21% from baseline, but returned nearly to baseline after 2.5 years of follow-up. Based on these results, we suggest that CsA is effective in reducing proteinuria in patients with Alport syndrome but that this effect is temporary. Our data do not support the use of CsA therapy for proteinuric patients with AS, particularly if they have chronic renal failure.
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Affiliation(s)
- Laura Massella
- Department of Nephrology and Urology, Bambino Gesù Children's Hospital and Research Institute, Nephrology and Dialysis Unit, Piazza S. Onofrio 4, 00165, Rome, Italy.
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