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Novel and Founder Pathogenic Variants in X-Linked Alport Syndrome Families in Greece. Genes (Basel) 2022; 13:genes13122203. [PMID: 36553470 PMCID: PMC9778032 DOI: 10.3390/genes13122203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/08/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022] Open
Abstract
Alport syndrome (AS) is the most frequent monogenic inherited glomerulopathy and is also genetically and clinically heterogeneous. It is caused by semi-dominant pathogenic variants in the X-linked COL4A5 (NM_000495.5) gene or recessive variants in the COL4A3/COL4A4 (NM_000091.4/NM_000092.4) genes. The disease manifests in early childhood with persistent microhematuria and can progress to proteinuria and kidney failure in adolescence or early adulthood if left untreated. On biopsy, pathognomonic features include alternate thinning, thickening and lamellation of the glomerular basement membrane (GBM), in the presence of podocyte foot process effacement. Although previous studies indicate a prevalence of AS of about 1/50,000, a recent publication reported a predicted rate of pathogenic COL4A5 variants of 1/2320. We herewith present 98 patients (40 M/58 F) from 26 Greek families. We are selectively presenting the families segregating the X-linked form of AS with pathogenic variants in the COL4A5 gene. We found 21 different pathogenic variants, 12 novel: eight glycine and one proline substitutions in the collagenous domain, one cysteine substitution in the NC1 domain, two premature termination of translation codons, three splicing variants, one 5-bp insertion/frameshift variant, one indel-frameshift variant and four gross deletions. Notably, patients in six families we describe here and three families we reported previously, carried the COL4A5-p.G624D substitution, a founder defect encountered all over Europe which is hypomorphic with mostly milder symptomatology. Importantly, on several occasions, the correct genetic diagnosis reclassified patients as patients with AS, leading to termination of previous immunosuppressive/cyclosporine A therapy and a switch to angiotensin converting enzyme inhibitors (ACEi). With the understanding that all 98 patients span a wide range of ages from infancy to late adulthood, 15 patients (11 M/4 F) reached kidney failure and 11 (10 M/1 F) received a transplant. The prospects of avoiding lengthy diagnostic investigations and erroneous medications, and the advantage of delaying kidney failure with very early administration of renin-angiotensin-aldosterone system (RAAS) blockade, highlights the importance of timely documentation of AS by genetic diagnosis.
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Cortvrindt C, Speeckaert R, Delanghe JR, Speeckaert MM. Urinary Epidermal Growth Factor: A Promising "Next Generation" Biomarker in Kidney Disease. Am J Nephrol 2022; 53:372-387. [PMID: 35537382 DOI: 10.1159/000524586] [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: 01/29/2022] [Accepted: 04/06/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND The epidermal growth factor (EGF) is a globular protein that is generated in the kidney, especially in the loop of Henle and the distal convoluted tubule. While EGF is nonexistent or hardly detectable in plasma, it is present in normal people's urine. Until now, risk stratification and chronic kidney disease (CKD) diagnosis have relied on estimated glomerular filtration rate (eGFR) and urine albumin/creatinine ratio (uACR), both of which reflect glomerular function or impairment. Tubular dysfunction, on the other hand, may also be associated with renal failure. SUMMARY Because decreased urine EGF (uEGF) indicates tubular atrophy and interstitial fibrosis, this biomarker, together with eGFR and uACR, may be employed in the general population for risk assessment and diagnosis of CKD. uEGF levels have been shown to correlate with intrarenal EGF mRNA expression and have been found to decrease in a variety of glomerular and non-glomerular kidney disorders. KEY MESSAGE uEGF, uEGF/creatinine, or uEGF/monocyte chemotactic peptide-1 are possible "new generation" biomarkers linked to a variety of kidney diseases that deserve further investigation as a single biomarker or as part of a multi-biomarker panel.
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Affiliation(s)
| | | | - Joris R Delanghe
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Marijn M Speeckaert
- Department of Nephrology, Ghent University Hospital, Ghent, Belgium
- Research Foundation-Flanders (FWO), Brussels, Belgium
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The 2019 and 2021 International Workshops on Alport Syndrome. Eur J Hum Genet 2022; 30:507-516. [PMID: 35260866 PMCID: PMC8904161 DOI: 10.1038/s41431-022-01075-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/04/2022] [Accepted: 02/14/2022] [Indexed: 01/27/2023] Open
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Rubel D, Boulanger J, Craciun F, Xu EY, Zhang Y, Phillips L, Callahan M, Weber W, Song W, Ngai N, Bukanov NO, Shi X, Hariri A, Husson H, Ibraghimov-Beskrovnaya O, Liu S, Gross O. Anti-microRNA-21 Therapy on Top of ACE Inhibition Delays Renal Failure in Alport Syndrome Mouse Models. Cells 2022; 11:cells11040594. [PMID: 35203245 PMCID: PMC8869926 DOI: 10.3390/cells11040594] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/28/2022] [Accepted: 02/03/2022] [Indexed: 02/01/2023] Open
Abstract
Col4a3−/− Alport mice serve as an animal model for renal fibrosis. MicroRNA-21 (miR-21) expression has been shown to be increased in the kidneys of Alport syndrome patients. Here, we investigated the nephroprotective effects of Lademirsen anti-miR-21 therapy. We used a fast-progressing Col4a3−/− mouse model with a 129/SvJ background and an intermediate-progressing F1 hybrid mouse model with a mixed genetic background, with angiotensin-converting enzyme inhibitor (ACEi) monotherapy in combination with anti-miR-21 therapy. In the fast-progressing model, the anti miR-21 and ACEi therapies showed an additive effect in the reduction in fibrosis, the decline of proteinuria, the preservation of kidney function and increased survival. In the intermediate-progressing F1 model, the anti-miR-21 and ACEi therapies individually improved kidney pathology. Both also improved kidney function and survival; however, the combination showed a significant additive effect, particularly for survival. RNA sequencing (RNA-seq) gene expression profiling revealed that the anti-miR-21 and ACEi therapies modulate several common pathways. However, anti-miR-21 was particularly effective at normalizing the expression profiles of the genes involved in renal tubulointerstitial injury pathways. In conclusion, significant additive effects were detected for the combination of anti-miR-21 and ACEi therapies on kidney function, pathology and survival in Alport mouse models, as well as a strong differential effect of anti-miR-21 on the renal expression of fibrotic factors. These results support the addition of anti-miR-21 to the current standard of care (ACEi) in ongoing clinical trials in patients with Alport syndrome.
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Affiliation(s)
- Diana Rubel
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany; (D.R.); (Y.Z.)
| | | | - Florin Craciun
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Ethan Y. Xu
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Excision BioTherapeutics, San Francisco, CA 94111, USA
| | - Yanqin Zhang
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany; (D.R.); (Y.Z.)
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Lucy Phillips
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Abbvie Bioresearch Center, Worcester, MA 01605, USA
| | - Michelle Callahan
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - William Weber
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Takeda Pharmaceuticals, Cambridge, MA 02139, USA
| | - Wenping Song
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Nicholas Ngai
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Nikolay O. Bukanov
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Janssen Pharmaceuticals, Boston, MA 02115, USA
| | - Xingyi Shi
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Novartis Institute for BioMedical Research, Boston, MA 02139, USA
| | - Ali Hariri
- Sanofi-Genzyme, Clinical Development, Cambridge, MA 02142, USA; (A.H.); (S.L.)
- Eloxx Pharmaceuticals, Watertown, MA 02140, USA
| | - Hervé Husson
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Oxana Ibraghimov-Beskrovnaya
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Dyne Therapeutics, Waltham, MA 02451, USA
| | - Shiguang Liu
- Sanofi-Genzyme, Clinical Development, Cambridge, MA 02142, USA; (A.H.); (S.L.)
| | - Oliver Gross
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany; (D.R.); (Y.Z.)
- Correspondence: ; Tel.: +49-551-39-60488
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Single, Double and Triple Blockade of RAAS in Alport Syndrome: Different Tools to Freeze the Evolution of the Disease. J Clin Med 2021; 10:jcm10214946. [PMID: 34768466 PMCID: PMC8584724 DOI: 10.3390/jcm10214946] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/17/2021] [Accepted: 10/20/2021] [Indexed: 12/29/2022] Open
Abstract
Background: The goal of the treatment of Alport syndrome (AS) is to delay the progression of kidney damage. The current standard of care is the use of Renin Angiotensin Aldosterone System (RAAS) blockers: angiotensin-converting enzyme inhibition (ACEi), angiotensin receptor blockade, and, recently, spironolactone (SP). Aim of the study: the purpose of this retrospective study is to evaluate the efficacy (reduction of proteinuria and changes of glomerular function) and safety of a sequential introduction of RAAS blockers up to a triple RAAS blockade in pediatric proteinuric patients with AS. Methods: in this retrospective study (1995 to 2019), we evaluated proteinuria values in AS patients, during the 12 months following the beginning of a new RAAS blocker, up to a triple blockade. ACEi was always the first line of treatment; then ARB and SP were sequentially added if uPCR increased by 50% from the basal level in 2 consecutive samples during a 3-months observation period, or when uPCR ratio was >2 mg/mg. Results: 26 patients (mean age at treatment onset was 10.55 ± 5.02 years) were enrolled. All patients were on ACEi, 14/26 were started on a second drug (6/14 ARB, 8/14 SP) after a mean time of 2.2 ± 1.7 years, 7/26 were on triple RAAS blockade after a further period of 5.5 ± 2.3 years from the introduction of a second drug. Repeated Measure Anova analysis of log-transformed data shows that the reduction of uPCR values after Time 0 from the introduction of the first, second and third drug is highly significant in all three cases (p values = 0.0016, 0.003, and 0.014, respectively). No significant changes in eGFR were recorded in any group, apart from a 15-year-old boy with X-linked AS, who developed kidney failure. One patient developed mild hyperkaliemia, and one gynecomastia and symptomatic hypotension. No life-threatening events were recorded. Conclusions: double and triple RAAS blockade is an effective and safe strategy to reduce proteinuria in children with AS. Nevertheless, we suggest monitoring eGFR and Kaliemia during follow-up.
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Chimenz R, Chirico V, Basile P, Carcione A, Conti G, Monardo P, Lacquaniti A. HMGB-1 and TGFβ-1 highlight immuno-inflammatory and fibrotic processes before proteinuria onset in pediatric patients with Alport syndrome. J Nephrol 2021; 34:1915-1924. [PMID: 33761123 DOI: 10.1007/s40620-021-01015-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 03/02/2021] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Alport syndrome (ALP) is a rare genetic condition characterized by progressive involvement of the basal membranes and renal dysfunction. The purpose of the study was to evaluate urinary (u) and serum (s) levels of tumor growth factor (TGF)-beta(β) and high mobility group box (HMGB)-1 in ALP patients with normal renal function, albuminuria and proteinuria. METHODS A prospective, single-center study was performed with a follow-up period of 12 months, enrolling 11 pediatric ALP patients and 10 healthy subjects (HS). Normal values of serum creatinine, albuminuria and proteinuria, as well as unaltered estimated glomerular filtration rate (eGFR) were required at enrollment. RESULTS ALP patients had significantly higher levels of serum and urinary HMGB1 compared to HS. The same trend was observed for TGF-β1, with higher values in ALP patients than in HS. HMGB1 and TGF-β1 correlated with each other and with markers of renal function and damage. Urinary biomarkers did not correlate with eGFR, whereas sHMGB1 and sTGF-β1 were negatively related to filtration rate (r: - 0.66; p = 0.02, r: - 0.96; p < 0.0001, respectively). Using proteinuria as a dependent variable in a multiple regression model, only the association with sTGF-β1 (β = 0.91, p < 0.0001) remained significant. CONCLUSIONS High levels of HMGB1 and TGF-β1 characterized ALP patients with normal renal function, highlighting the subclinical pro-fibrotic and inflammatory mechanisms triggered before the onset of proteinuria. Further studies are needed to evaluate the role of HMGB1 and TGFβ-1 in ALP patients.
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Affiliation(s)
- R Chimenz
- Pediatric Nephrology and Dialysis Unit, University Hospital "G. Martino", Messina, Italy.
| | - V Chirico
- Pediatric Nephrology and Dialysis Unit, University Hospital "G. Martino", Messina, Italy
| | - P Basile
- Pediatric Nephrology and Dialysis Unit, University Hospital "G. Martino", Messina, Italy
| | - A Carcione
- Pediatric Nephrology and Dialysis Unit, University Hospital "G. Martino", Messina, Italy
| | - G Conti
- Pediatric Nephrology and Dialysis Unit, University Hospital "G. Martino", Messina, Italy
| | - P Monardo
- Nephrology and Dialysis Unit, Papardo Hospital, Messina, Italy
| | - A Lacquaniti
- Nephrology and Dialysis Unit, Papardo Hospital, Messina, Italy
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Kashtan CE, Gross O. Clinical practice recommendations for the diagnosis and management of Alport syndrome in children, adolescents, and young adults-an update for 2020. Pediatr Nephrol 2021; 36:711-719. [PMID: 33159213 DOI: 10.1007/s00467-020-04819-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/24/2020] [Accepted: 10/08/2020] [Indexed: 12/28/2022]
Abstract
In 2013, we published a set of clinical practice recommendations for the treatment of Alport syndrome in this journal. We recommended delaying the initiation of angiotensin-converting enzyme inhibition until the onset of overt proteinuria or, in some cases, microalbuminuria. Developments that have occurred over the past 7 years have prompted us to revise these recommendations. We now recommend the initiation of treatment at the time of diagnosis in males with X-linked Alport syndrome and in males and females with autosomal recessive Alport syndrome. We further recommend starting treatment at the onset of microalbuminuria in females with X-linked Alport syndrome and in males and females with autosomal dominant Alport syndrome. This article presents the rationale for these revisions as well as recommendations for diagnostic tactics intended to ensure the early diagnosis of Alport syndrome.
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Affiliation(s)
- Clifford E Kashtan
- Department of Pediatrics, Division of Pediatric Nephrology, University of Minnesota Medical School, 2450 Riverside Avenue, Minneapolis, MN, 55454, USA.
| | - Oliver Gross
- Department of Nephrology and Rheumatology, University Medical Center Goettingen, Goettingen, Germany
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Abstract
Podocytopathies are kidney diseases in which direct or indirect podocyte injury drives proteinuria or nephrotic syndrome. In children and young adults, genetic variants in >50 podocyte-expressed genes, syndromal non-podocyte-specific genes and phenocopies with other underlying genetic abnormalities cause podocytopathies associated with steroid-resistant nephrotic syndrome or severe proteinuria. A variety of genetic variants likely contribute to disease development. Among genes with non-Mendelian inheritance, variants in APOL1 have the largest effect size. In addition to genetic variants, environmental triggers such as immune-related, infection-related, toxic and haemodynamic factors and obesity are also important causes of podocyte injury and frequently combine to cause various degrees of proteinuria in children and adults. Typical manifestations on kidney biopsy are minimal change lesions and focal segmental glomerulosclerosis lesions. Standard treatment for primary podocytopathies manifesting with focal segmental glomerulosclerosis lesions includes glucocorticoids and other immunosuppressive drugs; individuals not responding with a resolution of proteinuria have a poor renal prognosis. Renin-angiotensin system antagonists help to control proteinuria and slow the progression of fibrosis. Symptomatic management may include the use of diuretics, statins, infection prophylaxis and anticoagulation. This Primer discusses a shift in paradigm from patient stratification based on kidney biopsy findings towards personalized management based on clinical, morphological and genetic data as well as pathophysiological understanding.
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Zhang L, Sun BC, Zhao BG, Ma QS. An overview of the multi-pronged approach in the diagnosis of Alport syndrome for 22 children in Northeast China. BMC Nephrol 2020; 21:294. [PMID: 32703181 PMCID: PMC7379802 DOI: 10.1186/s12882-020-01962-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 07/17/2020] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Alport syndrome (AS) is a kind of progressive hereditary nephritis induced by mutations of different genes that encode collagen IV. The affected individuals usually develop hematuria during childhood, accompanying with gradual deterioration of renal functions. In this study, the multi-pronged approach was employed to improve the diagnosis of AS. METHODS Twenty-two children were diagnosed and treated at the Department of Pediatric Nephrology of Jilin University First Hospital between January 2017 and January 2020 using the multi-pronged approach. The following information was collected from patients, including age of onset, age at diagnosis, clinical manifestations, family history, renal pathology and genotype. RESULTS All these 22 children were diagnosed with Alport syndrome according to the diagnostic criteria formulated by the Japanese Society of Nephrology (2015), among them, only 13 children met the diagnostic criteria released in 1988. All the 22 patients presented with hematuria, and proteinuria to varying degrees was observed in some patients. Three children suffered from hearing loss, but no child in the cohort had any visual problem or renal failure. Meanwhile, five patients were estimated to be at Stage 2, whereas the remaining 17 cases were at Stage 0. Renal biopsies were performed in 18 patients, including 14 showing glomerular basement membranes (GBM)-specific abnormalities. Moreover, 13 children were detected with mutations of genes encoding collagen IV. CONCLUSIONS The multi-pronged approach helps to improve the diagnosis of AS. Most patients do not have renal failure during childhood, but close assessment and monitoring are necessary. Also, the advancements in treatment are reviewed.
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Affiliation(s)
- Li Zhang
- Department of Pediatric Nephrology, First Hospital, Jilin University, Changchun, 130021 Jilin China
| | - Bai-chao Sun
- Department of Pediatric Nephrology, First Hospital, Jilin University, Changchun, 130021 Jilin China
| | - Bing-gang Zhao
- Department of Pediatric Nephrology, First Hospital, Jilin University, Changchun, 130021 Jilin China
| | - Qing-shan Ma
- Department of Pediatric Nephrology, First Hospital, Jilin University, Changchun, 130021 Jilin China
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Torra R, Furlano M. New therapeutic options for Alport syndrome. Nephrol Dial Transplant 2020; 34:1272-1279. [PMID: 31190059 DOI: 10.1093/ndt/gfz131] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/31/2019] [Indexed: 12/12/2022] Open
Abstract
Alport syndrome (AS) is the most frequent inherited kidney disease after autosomal dominant polycystic kidney disease. It has three different patterns of inheritance-autosomal dominant, autosomal recessive and X-linked-which in part explains the wide spectrum of disease, ranging from isolated microhaematuria to end-stage renal disease early in life. The search for a treatment for AS is being pursued vigorously, not only because of the obvious unmet need but also because AS is a rare disease and any drug approved will have an orphan drug designation with its various benefits. Moreover, AS patients are quite young with very few comorbidities, which facilitates clinical trials. This review identifies the particularities of each pattern of inheritance but focuses mainly on new drugs or therapeutic targets for the disease. Most treatment-related investigations are directed not at the main abnormality in AS, namely collagen IV composition, but rather at the associated inflammation and fibrosis. Thus, AS may serve as a proof of concept for numerous drugs of potential value in many diseases that cause chronic kidney disease.
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Affiliation(s)
- Roser Torra
- Inherited Renal Disorders, Nephrology Department, Fundació Puigvert, REDINREN, IIB Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Mónica Furlano
- Inherited Renal Disorders, Nephrology Department, Fundació Puigvert, REDINREN, IIB Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
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Basement membrane collagens and disease mechanisms. Essays Biochem 2019; 63:297-312. [PMID: 31387942 PMCID: PMC6744580 DOI: 10.1042/ebc20180071] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/09/2019] [Accepted: 07/22/2019] [Indexed: 12/28/2022]
Abstract
Basement membranes (BMs) are specialised extracellular matrix (ECM) structures and collagens are a key component required for BM function. While collagen IV is the major BM collagen, collagens VI, VII, XV, XVII and XVIII are also present. Mutations in these collagens cause rare multi-systemic diseases but these collagens have also been associated with major common diseases including stroke. Developing treatments for these conditions will require a collective effort to increase our fundamental understanding of the biology of these collagens and the mechanisms by which mutations therein cause disease. Novel insights into pathomolecular disease mechanisms and cellular responses to these mutations has been exploited to develop proof-of-concept treatment strategies in animal models. Combined, these studies have also highlighted the complexity of the disease mechanisms and the need to obtain a more complete understanding of these mechanisms. The identification of pathomolecular mechanisms of collagen mutations shared between different disorders represent an attractive prospect for treatments that may be effective across phenotypically distinct disorders.
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Nephroprotektive Therapie am Beispiel des Alport-Syndroms. Monatsschr Kinderheilkd 2019. [DOI: 10.1007/s00112-018-0641-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Guo J, Song W, Boulanger J, Xu EY, Wang F, Zhang Y, He Q, Wang S, Yang L, Pryce C, Phillips L, MacKenna D, Leberer E, Ibraghimov-Beskrovnaya O, Ding J, Liu S. Dysregulated Expression of microRNA-21 and Disease-Related Genes in Human Patients and in a Mouse Model of Alport Syndrome. Hum Gene Ther 2019; 30:865-881. [PMID: 30808234 DOI: 10.1089/hum.2018.205] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Alport syndrome is a genetic disease caused by mutations in type IV collagen and is characterized by progressive kidney disease. The Col4α3-/- mouse model recapitulates the main features of human Alport syndrome. Previously, it was reported that kidney microRNA-21 (miR-21) expression is significantly increased in Col4α3-/- mice, and administration of anti-miR-21 oligonucleotides (anti-miR-21) attenuates kidney disease progression in Col4α3-/- mice, indicating that miR-21 is a viable therapeutic target for Alport syndrome. However, the expression pattern of miR-21 in the kidneys of patients with human Alport syndrome has not been evaluated. Paraffin-embedded kidney specimens were obtained from 27 patients with Alport syndrome and from 10 normal controls. They were evaluated for miR-21 expression and for in situ hybridization and mRNA expression by quantitative polymerase chain reaction. In addition, anti-miR-21 was administrated to Col4α3-/- mice at different stages of disease, and changes in proteinuria, kidney function, and survival were monitored. Transcriptomic analysis of mouse kidney was conducted using RNA sequencing. miR-21 expression was significantly elevated in kidney specimens from patients with Alport syndrome compared to normal controls. Elevated renal miR-21 expression positively correlated with 24 h urine protein, serum blood urea nitrogen, serum creatinine, and severity of kidney pathology. On histological evaluation, high levels of miR-21 were localized to damaged tubular epithelial cells and glomeruli. Kidney specimens from both humans and mice with Alport syndrome exhibited abnormal expression of genes involved in kidney injury, fibrosis, inflammation, mitochondrial function, and lipid metabolism. Administration of anti-miR-21 to Alport mice resulted in slowing of kidney function decline, partial reversal of abnormal gene expression associated with disease pathology, and improved survival. Increased levels of miR-21 in human Alport kidney samples showed a correlation with kidney disease severity measured by proteinuria, biomarkers of kidney function, and kidney histopathology scores. These human data, combined with the finding that a reduction of miR-21 in Col4α3-/- mice improves kidney phenotype and survival, support miR-21 as a viable therapeutic target for the treatment of Alport syndrome.
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Affiliation(s)
- Jifan Guo
- 1Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Wenping Song
- 2Rare Disease Research, Sanofi Genzyme, Framingham, Massachusetts
| | - Joseph Boulanger
- 2Rare Disease Research, Sanofi Genzyme, Framingham, Massachusetts
| | - Ethan Y Xu
- 3Translational Sciences, Sanofi Genzyme, Framingham, Massachusetts
| | - Fang Wang
- 1Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Yanqin Zhang
- 1Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Qun He
- 4Department of Urology, Peking University First Hospital, Beijing, P.R. China
| | - Suxia Wang
- 5Laboratory of Electron Microscopy, Peking University First Hospital, Beijing, P.R. China
| | - Li Yang
- 6Department of Internal Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, P.R. China
| | - Cynthia Pryce
- 2Rare Disease Research, Sanofi Genzyme, Framingham, Massachusetts
| | - Lucy Phillips
- 2Rare Disease Research, Sanofi Genzyme, Framingham, Massachusetts
| | | | | | | | - Jie Ding
- 1Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Shiguang Liu
- 2Rare Disease Research, Sanofi Genzyme, Framingham, Massachusetts
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14
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Gross O, Hoefele J. Genetische Ursachen und Therapie beim Alport-Syndrom. MED GENET-BERLIN 2019. [DOI: 10.1007/s11825-018-0214-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zusammenfassung
Bei der Typ IV Kollagen-Erkrankung Alport-Syndrom (AS) handelt es sich um eine progressive hereditäre Nephropathie. Klinische Zeichen sind zunächst Hämaturie und Proteinurie, im weiteren Verlauf kommt es zu einem terminalen Nierenversagen. Zusätzlich werden extrarenale Manifestationen wie Innenohr-Schwerhörigkeit und Augenveränderungen beobachtet. Man unterscheidet drei Erbgänge: 85 % der Fälle sind X-chromosomal, ca. 10 % autosomal und weniger als 5 % digenisch. Ursächlich sind Varianten in den Kollagen Typ IV-Genen COL4A3, COL4A4 (beide autosomal) und COL4A5 (X-chromosomal). Die Symptomatik heterozygoter Anlageträger wurde früher als benigne familiäre Hämaturie bezeichnet. Da Anlageträger jedoch häufig keinen benignen Verlauf zeigen, werden sie inzwischen auch unter der Diagnose „Alport-Syndrom“ geführt.
Der Humangenetiker hat daher beim AS eine wichtige Lotsenfunktion: Bei früher Diagnose ist das AS inzwischen gut behandelbar, wodurch das terminale Nierenversagen um mehrere Jahre hinausgezögert und damit die Lebenserwartung verbessert werden kann. Aufgrund der Therapiemöglichkeiten sollte die (molekulargenetische) Diagnose bei Betroffenen, auch bei heterozygoten Anlageträgern, frühzeitig gestellt werden.
Mit diesem Artikel sollen die genetischen Ursachen des AS, mögliche genetische Einflussfaktoren auf den variablen Phänotyp, die unterschiedlichen Krankheitsstadien, Komplikationen sowie die derzeit zugelassene Behandlung aufgezeigt werden, um eine bestmögliche lebenslange Betreuung des Patienten zu gewährleisten.
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Affiliation(s)
- Oliver Gross
- Aff1 0000 0001 0482 5331 grid.411984.1 Klinik für Nephrologie und Rheumatologie Universitätsmedizin Göttingen Robert-Koch Str. 40 37075 Göttingen Deutschland
| | - Julia Hoefele
- Aff2 Institut für Humangenetik Klinikum rechts der Isar, Technische Universität München Trogerstr. 32 81675 München Deutschland
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15
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Urinary epidermal growth factor as a prognostic marker for the progression of Alport syndrome in children. Pediatr Nephrol 2018; 33:1731-1739. [PMID: 29948307 PMCID: PMC6132884 DOI: 10.1007/s00467-018-3988-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/21/2018] [Accepted: 05/25/2018] [Indexed: 11/21/2022]
Abstract
BACKGROUND Alport syndrome is a rare hereditary kidney disease manifested with progressive renal failure. Considerable variation exists in terms of disease progression among patients with Alport syndrome. Identification of patients at high risk of rapid progression remains an unmet need. Urinary epidermal growth factor (uEGF) has been shown to be independently associated with risk of progression to adverse kidney outcome in multiple independent adult chronic kidney disease (CKD) cohorts. In this study, we aim to assess if uEGF is associated with kidney impairment and its prognostic value for children with Alport syndrome. METHODS One hundred and seventeen pediatric patients with Alport syndrome and 146 healthy children (3-18 years old) were included in this study. uEGF was measured in duplicates in baseline urine samples using ELISA (R&D) and concentration was normalized by urine creatinine (uEGF/Cr). In patients with longitudinal follow-up data (n = 38), progression was defined as deteriorated kidney function (CKD stage increase) during follow-up period (follow-up length is about 31 months in average). The association of baseline uEGF/Cr level with estimated glomerular filtration rate (eGFR) slope and Alport syndrome patients' progression to a more advanced CKD stage during the follow-up period was used to evaluate the prognostic value of the marker. RESULTS We found that uEGF/creatinine (uEGF/Cr) decreases with age in pediatric patients with Alport syndrome with a significantly faster rate than in healthy children of the same age group. uEGF/Cr is significantly correlated with eGFR (r = 0.75, p < 0.001), after adjustment for age. In 38 patients with longitudinal follow-up, we observed a significant correlation between uEGF/Cr and eGFR slope (r = 0.58, p < 0.001). Patients with lower uEGF/Cr level were at increased risk of progression to a higher CKD stage. uEGF/Cr was able to distinguish progressors from non-progressors with an AUC of 0.88, versus 0.77 by eGFR and 0.81 by 24-h urinary protein (24-h UP). CONCLUSIONS Our study suggests that uEGF/Cr is a promising biomarker for accelerated kidney function decline in pediatric patients with Alport syndrome. It may help to identify patients at high risk of progression for targeted clinical care and improve the patients' stratification in interventional trials.
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16
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Williams MJ, Sugatani T, Agapova OA, Fang Y, Gaut JP, Faugere MC, Malluche HH, Hruska KA. The activin receptor is stimulated in the skeleton, vasculature, heart, and kidney during chronic kidney disease. Kidney Int 2018; 93:147-158. [PMID: 28843411 PMCID: PMC6628245 DOI: 10.1016/j.kint.2017.06.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/02/2017] [Accepted: 06/08/2017] [Indexed: 01/09/2023]
Abstract
We examined activin receptor type IIA (ActRIIA) activation in chronic kidney disease (CKD) by signal analysis and inhibition in mice with Alport syndrome using the ActRIIA ligand trap RAP-011 initiated in 75-day-old Alport mice. At 200 days of age, there was severe CKD and associated Mineral and Bone Disorder (CKD-MBD), consisting of osteodystrophy, vascular calcification, cardiac hypertrophy, hyperphosphatemia, hyperparathyroidism, elevated FGF23, and reduced klotho. The CKD-induced bone resorption and osteoblast dysfunction was reversed, and bone formation was increased by RAP-011. ActRIIA inhibition prevented the formation of calcium apatite deposits in the aortic adventitia and tunica media and significantly decreased the mean aortic calcium concentration from 0.59 in untreated to 0.36 mg/g in treated Alport mice. Aortic ActRIIA stimulation in untreated mice increased p-Smad2 levels and the transcription of sm22α and αSMA. ActRIIA inhibition reversed aortic expression of the osteoblast transition markers Runx2 and osterix. Heart weight was significantly increased by 26% in untreated mice but remained normal during RAP-011 treatment. In 150-day-old mice, GFR was significantly reduced by 55%, but only by 30% in the RAP-011-treated group. In 200-day-old mice, the mean BUN was 100 mg/dl in untreated mice compared to 60 mg/dl in the treated group. In the kidneys of 200-day-old mice, ActRIIA and p-Smad2 were induced and MCP-1, fibronectin, and interstitial fibrosis were stimulated; all were attenuated by RAP-011 treatment. Hence, the activation of ActRIIA signaling during early CKD contributes to the CKD-MBD components of osteodystrophy and cardiovascular disease and to renal fibrosis. Thus, the inhibition of ActRIIA signaling is efficacious in improving and delaying CKD-MBD in this model of Alport syndrome.
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MESH Headings
- Actins/metabolism
- Activin Receptors, Type II/antagonists & inhibitors
- Activin Receptors, Type II/genetics
- Activin Receptors, Type II/metabolism
- Animals
- Blood Vessels/metabolism
- Blood Vessels/pathology
- Blood Vessels/physiopathology
- Bone Remodeling
- Bone Resorption/genetics
- Bone Resorption/metabolism
- Bone Resorption/physiopathology
- Bone Resorption/prevention & control
- Bone and Bones/metabolism
- Bone and Bones/pathology
- Bone and Bones/physiopathology
- Cardiomegaly/genetics
- Cardiomegaly/metabolism
- Cardiomegaly/physiopathology
- Cardiomegaly/prevention & control
- Chronic Kidney Disease-Mineral and Bone Disorder/genetics
- Chronic Kidney Disease-Mineral and Bone Disorder/metabolism
- Chronic Kidney Disease-Mineral and Bone Disorder/physiopathology
- Chronic Kidney Disease-Mineral and Bone Disorder/prevention & control
- Collagen Type IV/deficiency
- Collagen Type IV/genetics
- Core Binding Factor Alpha 1 Subunit/metabolism
- Disease Models, Animal
- Fibroblast Growth Factor-23
- Fibrosis
- Glomerular Filtration Rate
- Kidney/metabolism
- Kidney/pathology
- Kidney/physiopathology
- Mice, Knockout
- Microfilament Proteins/metabolism
- Muscle Proteins/metabolism
- Myocardium/metabolism
- Myocardium/pathology
- Nephritis, Hereditary/drug therapy
- Nephritis, Hereditary/genetics
- Nephritis, Hereditary/metabolism
- Nephritis, Hereditary/physiopathology
- Phosphorylation
- Recombinant Fusion Proteins/pharmacology
- Renal Insufficiency, Chronic/genetics
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/physiopathology
- Renal Insufficiency, Chronic/prevention & control
- Signal Transduction
- Smad2 Protein/metabolism
- Sp7 Transcription Factor/metabolism
- Vascular Calcification/genetics
- Vascular Calcification/metabolism
- Vascular Calcification/physiopathology
- Vascular Calcification/prevention & control
- Vascular Remodeling
- Ventricular Remodeling
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Affiliation(s)
- Matthew J Williams
- Renal Division, Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Toshifumi Sugatani
- Renal Division, Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Olga A Agapova
- Renal Division, Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Yifu Fang
- Renal Division, Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Joseph P Gaut
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Marie-Claude Faugere
- Renal Division Department of Medicine, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Hartmut H Malluche
- Renal Division Department of Medicine, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Keith A Hruska
- Renal Division, Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, USA; Departments of Medicine and Cell Biology, Washington University School of Medicine, Saint Louis, Missouri, USA.
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17
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Kamijo M, Kitamura M, Muta K, Uramatsu T, Obata Y, Nozu K, Kaito H, Iijima K, Mukae H, Nishino T. A case of mild phenotype Alport syndrome caused by COL4A3 mutations. CEN Case Rep 2017; 6:189-193. [PMID: 28856578 DOI: 10.1007/s13730-017-0273-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 08/22/2017] [Indexed: 11/28/2022] Open
Abstract
In a case of 41-year-old man with mild nephropathy, Alport syndrome (AS) was diagnosed from the renal biopsy. However, the α5 chain of type IV collagen expressed in the glomerular basement membrane, which was the atypical staining pattern of AS. Genetic testing suggested autosomal recessive AS from heterozygous mutations at two positions in the type IV collagen α3 chain. These two gene mutations represented a new pattern of mutation and was suggested the association with an atypical α5 chain expression and mild phenotype.
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Affiliation(s)
- Masafumi Kamijo
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Mineaki Kitamura
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan.
| | - Kumiko Muta
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Tadashi Uramatsu
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Yoko Obata
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroshi Kaito
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroshi Mukae
- Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki, Japan
| | - Tomoya Nishino
- Department of Nephrology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki, 852-8501, Japan
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18
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Gross O, Kashtan CE, Rheault MN, Flinter F, Savige J, Miner JH, Torra R, Ars E, Deltas C, Savva I, Perin L, Renieri A, Ariani F, Mari F, Baigent C, Judge P, Knebelman B, Heidet L, Lagas S, Blatt D, Ding J, Zhang Y, Gale DP, Prunotto M, Xue Y, Schachter AD, Morton LC, Blem J, Huang M, Liu S, Vallee S, Renault D, Schifter J, Skelding J, Gear S, Friede T, Turner AN, Lennon R. Advances and unmet needs in genetic, basic and clinical science in Alport syndrome: report from the 2015 International Workshop on Alport Syndrome. Nephrol Dial Transplant 2017; 32:916-924. [PMID: 27190345 PMCID: PMC5837236 DOI: 10.1093/ndt/gfw095] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/21/2016] [Accepted: 03/29/2016] [Indexed: 12/27/2022] Open
Abstract
Alport syndrome (AS) is a genetic disease characterized by haematuric glomerulopathy variably associated with hearing loss and anterior lenticonus. It is caused by mutations in the COL4A3, COL4A4 or COL4A5 genes encoding the α3α4α5(IV) collagen heterotrimer. AS is rare, but it accounts for >1% of patients receiving renal replacement therapy. Angiotensin-converting enzyme inhibition slows, but does not stop, the progression to renal failure; therefore, there is an urgent requirement to expand and intensify research towards discovering new therapeutic targets and new therapies. The 2015 International Workshop on Alport Syndrome targeted unmet needs in basic science, genetics and diagnosis, clinical research and current clinical care. In three intensive days, more than 100 international experts including physicians, geneticists, researchers from academia and industry, and patient representatives from all over the world participated in panel discussions and breakout groups. This report summarizes the most important priority areas including (i) understanding the crucial role of podocyte protection and regeneration, (ii) targeting mutations by new molecular techniques for new animal models and potential gene therapy, (iii) creating optimal interaction between nephrologists and geneticists for early diagnosis, (iv) establishing standards for mutation screening and databases, (v) improving widespread accessibility to current standards of clinical care, (vi) improving collaboration with the pharmaceutical/biotech industry to investigate new therapies, (vii) research in hearing loss as a huge unmet need in Alport patients and (viii) the need to evaluate the risk and benefit of novel (including 'repurposing') therapies on an international basis.
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Affiliation(s)
- Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medicine Goettingen, Goettingen, Germany
| | - Clifford E. Kashtan
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Michelle N. Rheault
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Frances Flinter
- Department of Clinical Genetics, Guy's and St Thomas’ NHS Foundation Trust, London, UK
| | - Judith Savige
- Melbourne Health, The University of Melbourne, Parkville, VIC, Australia
| | - Jeffrey H. Miner
- Division of Nephrology, Washington University School of Medicine, St Louis, MO, USA
| | - Roser Torra
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, IIB Sant Pau, Universitat Autònoma de Barcelona and REDINREN, Barcelona, Spain
| | - Elisabet Ars
- Inherited Kidney Diseases, Nephrology Department, Fundació Puigvert, IIB Sant Pau, Universitat Autònoma de Barcelona and REDINREN, Barcelona, Spain
| | - Constantinos Deltas
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Isavella Savva
- Molecular Medicine Research Center, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Laura Perin
- University of Southern California, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Alessandra Renieri
- Medical Genetics Unit, University of Siena, Siena, Italy
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Ariani
- Medical Genetics Unit, University of Siena, Siena, Italy
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Francesca Mari
- Medical Genetics Unit, University of Siena, Siena, Italy
- Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Colin Baigent
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Parminder Judge
- Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Bertrand Knebelman
- Division de Néphrologie, Hôpital Necker, Assistance Publique-Hôpitaux de Paris, Paris, France
- Université Paris Descartes, Paris, France
| | - Laurence Heidet
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA) Service de Néphrologie Pédiatrique, Clinique Maurice Lamy, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Dave Blatt
- Alport Foundation of Australia, Valentine, NSW, Australia
| | - Jie Ding
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Yanqin Zhang
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Daniel P. Gale
- University College London-Centre for Nephrology, London, UK
| | - Marco Prunotto
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Roche Pharma Research & Early Development, Basel, Switzerland
| | - Yong Xue
- Rare Disease Group-Therapeutic Area, Global Clinical Development, Sanofi Genzyme, Naarden, The Netherlands
| | - Asher D. Schachter
- New Indications Discovery Unit, Translational Medicine, Novartis Institutes for BioMedical Research, Cambridge, MA, USA
| | - Lori C.G. Morton
- Cardiovascular Research, Fibrosis Research, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Jacqui Blem
- Clinical Development, Regulus Therapeutics, San Diego, CA, USA
| | - Michael Huang
- Clinical Development, Regulus Therapeutics, San Diego, CA, USA
| | - Shiguang Liu
- Department of Rare Diseases, Sanofi-Genzyme R&D Center, Framingham, MA, USA
| | | | - Daniel Renault
- Association for Information and Research on Genetic Renal Diseases (AIRG)—France, Paris, France
- Federation of European Associations of patients affected by Genetic Renal Diseases, FEDERG, Brussels, Belgium
| | | | | | | | - Tim Friede
- Department of Medical Statistics, University Medical Center Goettingen, Goettingen, Germany
| | - A. Neil Turner
- Renal Medicine, Royal Infirmary, University of Edinburgh, Edinburgh, UK
| | - Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK
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19
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Prospective study on the potential of RAAS blockade to halt renal disease in Alport syndrome patients with heterozygous mutations. Pediatr Nephrol 2017; 32:131-137. [PMID: 27402170 DOI: 10.1007/s00467-016-3452-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/16/2016] [Accepted: 06/16/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Patients with autosomal or X-linked Alport syndrome (AS) with heterozygous mutations in type IV collagen genes have a 1-20 % risk of progressing to end-stage renal disease during their lifetime. We evaluated the long-term renal outcome of patients at risk of progressive disease (chronic kidney disease stages 1-4) with/without nephroprotective therapy. METHODS This was a prospective, non-interventional, observational study which included data from a 4-year follow-up of AS patients with heterozygous mutations whose datasets had been included in an analysis of the 2010 database of the European Alport Registry. Using Kaplan-Meier estimates and logrank tests, we prospectively analyzed the updated datasets of 52 of these patients and 13 new datasets (patients added to the Registry after 2011). The effects of therapy, extrarenal symptoms and inheritance pattern on renal outcome were analyzed. RESULTS The mean prospective follow-up was 46 ± 10 months, and the mean time on therapy was 8.4 ± 4.4 (median 7; range 2-18) years. The time from the appearance of the first symptom to diagnosis was 8.1 ± 14.2 (range 0-52) years. At the time of starting therapy, 5.4 % of patients had an estimated glomerular filtration rate of <60 ml/min, 67.6 % had proteinuria and 27.0 % had microalbuminuria. Therapeutic strategies included angiotensin-converting enzymer inhibitors (97.1 %), angiotensin receptor antagonists (1 patient), dual therapy (11.8 %) and statins (8.8 %). Among patients included in the prospective dataset, prevented the need for dialysis. Among new patients, no patient at risk for renal failure progressed to the next disease stage after 4 years follow-up; three patients even regressed to a lower stage during therapy. CONCLUSIONS Treatment with blockers of the renin-angiotensin-aldosterone system prevents progressive renal failure in AS patients with heterozygous mutations in the genes causing AS. Considerable numbers of aging AS patients on dialysis may have heterozygous mutations in these genes (present in 1 % of total population) as underlying disease. Hence, greater alertness towards timely diagnosis and therapy has the potential to prevent progressive renal failure in most-if not all-AS patients with heterozygous mutations in the causal genes.
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20
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Langsford D, Tang M, Djurdjev O, Er L, Levin A. The Variability of Estimated Glomerular Filtration Rate Decline in Alport Syndrome. Can J Kidney Health Dis 2016; 3:2054358116679129. [PMID: 28781883 PMCID: PMC5518963 DOI: 10.1177/2054358116679129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/12/2016] [Indexed: 11/17/2022] Open
Abstract
Background: A progressive trajectory toward renal failure is common in patients with Alport syndrome. Genotype-phenotype correlations have been well described; however, the natural history of the trajectory toward renal failure is not well described. Objective: The objective of this study is to describe the natural history of renal function decline in a cohort of Alport syndrome patients. Design: Retrospective observational cohort study. Setting: British Columbia, Canada, chronic renal disease registry 1995-2012. Patients: 37 biopsy proven Alport syndrome or hematuria with family history of Alport syndrome. Measurements: Serial estimated glomerular filtration rate (eGFR) Trajectory of renal decline described graphically by fitting a cubic smoothing spline to patient’s eGFR measures. Various time points within a trajectory were indexed, randomly sampled, and followed for 2 years to estimate portion of progressors (>5 mL/min/1.73 m2 /y decline), stable state (0-2 mL/min/1.73 m2 /y decline), and regressors (>2 mL/min/1.73 m2 /y incline). Methods: In this retrospective observational cohort study, participants were identified through a chronic renal disease registry in British Columbia, Canada, from 1995 to 2012. Inclusion criteria were biopsy proven or hematuria with a family history of Alport syndrome. Individual patients and family group members were studied. Trajectory of renal decline described graphically by fitting a cubic smoothing spline to patient’s serial estimated glomerular filtration rate (eGFR) measures. Various time points within a trajectory were indexed, randomly sampled, and followed for 2 years to estimate portion of progressors (>5 mL/min/1.73 m2/y decline), stable state (0-2 mL/min/1.73 m2/y decline), and regressors (>2 mL/min/1.73 m2/y incline). Limitations: Histological or genetic evidence of Alport syndrome is not available in all patients. Results: Median follow-up time was 48.2 months of 37 patients (78% male), with a median age of 36 (interquartile range [IQR], 18-47) and a median age of renal replacement therapy commencement (n = 23) of 38 (IQR = 20-52). Renal function changes were found to be heterogeneous overall, intra-individual and within families. Portion of progressors in eGFR 45-60 mL/min/1.73 m2 was 73.7% (SD, 10.3), whereas 23.6% (SD, 11.0) remained stable. Within eGFR 30-45 mL/min/1.73 m2, 45.6% (SD, 7.0) were progressors, whereas 53.4% (SD, 7.4) remained stable. A large portion of eGFR 15-30 mL/min/1.73 m2 patients were stable (54.8%; SD, 8.4), whereas 25.7% (SD, 7.1) progressed and 19.5% (SD, 5.6) regressed. Conclusions: The renal decline in Alport syndrome patients is heterogeneous which has implications for designing clinical trials of interventions.
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Affiliation(s)
| | | | | | - Lee Er
- BC Renal Agency, Vancouver, Canada
| | - Adeera Levin
- The University of British Columbia, Vancouver, Canada
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22
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Nyström A, Bornert O, Kühl T. Cell therapy for basement membrane-linked diseases. Matrix Biol 2016; 57-58:124-139. [PMID: 27609402 DOI: 10.1016/j.matbio.2016.07.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/02/2016] [Accepted: 07/07/2016] [Indexed: 12/14/2022]
Abstract
For most disorders caused by mutations in genes encoding basement membrane (BM) proteins, there are at present only limited treatment options available. Genetic BM-linked disorders can be viewed as especially suited for treatment with cell-based therapy approaches because the proteins that need to be restored are located in the extracellular space. In consequence, complete and permanent engraftment of cells does not necessarily have to occur to achieve substantial causal therapeutic effects. For these disorders cells can be used as transient vehicles for protein replacement. In addition, it is becoming evident that BM-linked genetic disorders are modified by secondary diseases mechanisms. Cell-based therapies have also the ability to target such disease modifying mechanisms. Thus, cell therapies can simultaneously provide causal treatment and symptomatic relief, and accordingly hold great potential for treatment of BM-linked disorders. However, this potential has for most applications and diseases so far not been realized. Here, we will present the state of cell therapies for BM-linked diseases. We will discuss use of both pluripotent and differentiated cells, the limitation of the approaches, their challenges, and the way forward to potential wider implementation of cell therapies in the clinics.
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Affiliation(s)
- Alexander Nyström
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany.
| | - Olivier Bornert
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany
| | - Tobias Kühl
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany
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23
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Peired AJ, Bitzer M. Albumin: innocent bystander or culprit? Am J Physiol Renal Physiol 2016; 311:F409-10. [PMID: 27306981 DOI: 10.1152/ajprenal.00317.2016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 06/08/2016] [Indexed: 11/22/2022] Open
Affiliation(s)
- Anna J Peired
- Excellence Centre for Research, Transfer and High Education for the Development of De Novo Therapies, Florence, Italy; Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy; and
| | - Markus Bitzer
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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24
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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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25
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Moschidou D, Corcelli M, Hau KL, Ekwalla VJ, Behmoaras JV, De Coppi P, David AL, Bou-Gharios G, Cook HT, Pusey CD, Fisk NM, Guillot PV. Human Chorionic Stem Cells: Podocyte Differentiation and Potential for the Treatment of Alport Syndrome. Stem Cells Dev 2016; 25:395-404. [DOI: 10.1089/scd.2015.0305] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Dafni Moschidou
- Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - Michelangelo Corcelli
- Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - Kwan-Leong Hau
- Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - Victoria J. Ekwalla
- Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - Jacques V. Behmoaras
- Division of Immunity and Inflammation, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Paolo De Coppi
- Department of Stem Cells and Regenerative Medicine, Institute of Child Health, University College London, London, United Kingdom
| | - Anna L. David
- Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
| | - George Bou-Gharios
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - H. Terence Cook
- Division of Immunity and Inflammation, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Charles D. Pusey
- Division of Immunity and Inflammation, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Nicholas M. Fisk
- UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia
| | - Pascale V. Guillot
- Department of Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, United Kingdom
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26
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Kim M, Piaia A, Shenoy N, Kagan D, Gapp B, Kueng B, Weber D, Dietrich W, Ksiazek I. Progression of Alport Kidney Disease in Col4a3 Knock Out Mice Is Independent of Sex or Macrophage Depletion by Clodronate Treatment. PLoS One 2015; 10:e0141231. [PMID: 26555339 PMCID: PMC4640715 DOI: 10.1371/journal.pone.0141231] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/05/2015] [Indexed: 01/09/2023] Open
Abstract
Alport syndrome is a genetic disease of collagen IV (α3, 4, 5) resulting in renal failure. This study was designed to investigate sex-phenotype correlations and evaluate the contribution of macrophage infiltration to disease progression using Col4a3 knock out (Col4a3KO) mice, an established genetic model of autosomal recessive Alport syndrome. No sex differences in the evolution of body mass loss, renal pathology, biomarkers of tubular damage KIM-1 and NGAL, or deterioration of kidney function were observed during the life span of Col4a3KO mice. These findings confirm that, similar to human autosomal recessive Alport syndrome, female and male Col4a3KO mice develop renal failure at the same age and with similar severity. The specific contribution of macrophage infiltration to Alport disease, one of the prominent features of the disease in human and Col4a3KO mice, remains unknown. This study shows that depletion of kidney macrophages in Col4a3KO male mice by administration of clodronate liposomes, prior to clinical onset of disease and throughout the study period, does not protect the mice from renal failure and interstitial fibrosis, nor delay disease progression. These results suggest that therapy targeting macrophage recruitment to kidney is unlikely to be effective as treatment of Alport syndrome.
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Affiliation(s)
- Munkyung Kim
- Developmental and Molecular Pathways, Novartis Institute for Biomedical Research, Basel, Switzerland
| | - Alessandro Piaia
- Preclinical Safety, Novartis Institute for Biomedical Research, Basel, Switzerland
| | - Neeta Shenoy
- Preclinical Safety, Novartis Institute for Biomedical Research, Cambridge, Massachusetts, Unites States of America
| | - David Kagan
- Preclinical Safety, Novartis Institute for Biomedical Research, Cambridge, Massachusetts, Unites States of America
| | - Berangere Gapp
- Developmental and Molecular Pathways, Novartis Institute for Biomedical Research, Basel, Switzerland
| | - Benjamin Kueng
- Developmental and Molecular Pathways, Novartis Institute for Biomedical Research, Basel, Switzerland
| | - Delphine Weber
- Developmental and Molecular Pathways, Novartis Institute for Biomedical Research, Basel, Switzerland
| | - William Dietrich
- Developmental and Molecular Pathways, Novartis Institute for Biomedical Research, Cambridge, Massachusetts, Unites States of America
| | - Iwona Ksiazek
- Developmental and Molecular Pathways, Novartis Institute for Biomedical Research, Basel, Switzerland
- * E-mail:
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27
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Muckova P, Wendler S, Rubel D, Büchler R, Alert M, Gross O, Rhode H. Preclinical Alterations in the Serum of COL(IV)A3–/– Mice as Early Biomarkers of Alport Syndrome. J Proteome Res 2015; 14:5202-14. [DOI: 10.1021/acs.jproteome.5b00814] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Petra Muckova
- Institute
of Biochemistry I, University Hospital Jena, Nonnenplan 2-4, 07740 Jena, Germany
- Clinic
of Neurology, University Hospital Jena, Erlanger Allee 101, 07740 Jena, Germany
| | - Sindy Wendler
- Institute
of Biochemistry I, University Hospital Jena, Nonnenplan 2-4, 07740 Jena, Germany
| | - Diana Rubel
- Department
of Nephrology and Rheumatology, University Medicine Göttingen, Robert-Koch Str. 40, 37075 Göttingen, Germany
| | - Rita Büchler
- Institute
of Biochemistry I, University Hospital Jena, Nonnenplan 2-4, 07740 Jena, Germany
| | - Mandy Alert
- Institute
of Biochemistry I, University Hospital Jena, Nonnenplan 2-4, 07740 Jena, Germany
| | - Oliver Gross
- Department
of Nephrology and Rheumatology, University Medicine Göttingen, Robert-Koch Str. 40, 37075 Göttingen, Germany
| | - Heidrun Rhode
- Institute
of Biochemistry I, University Hospital Jena, Nonnenplan 2-4, 07740 Jena, Germany
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28
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Rheault MN, Gbadegesin RA. The Genetics of Nephrotic Syndrome. J Pediatr Genet 2015; 5:15-24. [PMID: 27617138 DOI: 10.1055/s-0035-1557109] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/21/2015] [Indexed: 12/26/2022]
Abstract
Nephrotic syndrome (NS) is a common pediatric kidney disease and is defined as massive proteinuria, hypoalbuminemia, and edema. Dysfunction of the glomerular filtration barrier, which is made up of endothelial cells, glomerular basement membrane, and visceral epithelial cells known as podocytes, is evident in children with NS. While most children have steroid-responsive nephrotic syndrome (SSNS), approximately 20% have steroid-resistant nephrotic syndrome (SRNS) and are at risk for progressive kidney dysfunction. While the cause of SSNS is still not well understood, there has been an explosion of research into the genetic causes of SRNS in the past 15 years. More than 30 proteins regulating the function of the glomerular filtration barrier have been associated with SRNS including podocyte slit diaphragm proteins, podocyte actin cytoskeletal proteins, mitochondrial proteins, adhesion and glomerular basement membrane proteins, transcription factors, and others. A genetic cause of SRNS can be found in approximately 70% of infants presenting in the first 3 months of life and 50% of infants presenting between 4 and 12 months, with much lower likelihood for older patients. Identification of the underlying genetic etiology of SRNS is important in children because it allows for counseling of other family members who may be at risk, predicts risk of recurrent disease after kidney transplant, and predicts response to immunosuppressive therapy. Correlations between genetic mutation and clinical phenotype as well as genetic risk factors for SSNS and SRNS are reviewed in this article.
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Affiliation(s)
- Michelle N Rheault
- Division of Nephrology, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, United States
| | - Rasheed A Gbadegesin
- Division of Nephrology and Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States
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29
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Papazachariou L, Demosthenous P, Pieri M, Papagregoriou G, Savva I, Stavrou C, Zavros M, Athanasiou Y, Ioannou K, Patsias C, Panagides A, Potamitis C, Demetriou K, Prikis M, Hadjigavriel M, Kkolou M, Loukaidou P, Pastelli A, Michael A, Lazarou A, Arsali M, Damianou L, Goutziamani I, Soloukides A, Yioukas L, Elia A, Zouvani I, Polycarpou P, Pierides A, Voskarides K, Deltas C. Frequency of COL4A3/COL4A4 mutations amongst families segregating glomerular microscopic hematuria and evidence for activation of the unfolded protein response. Focal and segmental glomerulosclerosis is a frequent development during ageing. PLoS One 2014; 9:e115015. [PMID: 25514610 PMCID: PMC4267773 DOI: 10.1371/journal.pone.0115015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/17/2014] [Indexed: 12/29/2022] Open
Abstract
Familial glomerular hematuria(s) comprise a genetically heterogeneous group of conditions which include Alport Syndrome (AS) and thin basement membrane nephropathy (TBMN). Here we investigated 57 Greek-Cypriot families presenting glomerular microscopic hematuria (GMH), with or without proteinuria or chronic kidney function decline, but excluded classical AS. We specifically searched the COL4A3/A4 genes and identified 8 heterozygous mutations in 16 families (28,1%). Eight non-related families featured the founder mutation COL4A3-p.(G1334E). Renal biopsies from 8 patients showed TBMN and focal segmental glomerulosclerosis (FSGS). Ten patients (11.5%) reached end-stage kidney disease (ESKD) at ages ranging from 37-69-yo (mean 50,1-yo). Next generation sequencing of the patients who progressed to ESKD failed to reveal a second mutation in any of the COL4A3/A4/A5 genes, supporting that true heterozygosity for COL4A3/A4 mutations predisposes to CRF/ESKD. Although this could be viewed as a milder and late-onset form of autosomal dominant AS, we had no evidence of ultrastructural features or extrarenal manifestations that would justify this diagnosis. Functional studies in cultured podocytes transfected with wild type or mutant COL4A3 chains showed retention of mutant collagens and differential activation of the unfolded protein response (UPR) cascade. This signifies the potential role of the UPR cascade in modulating the final phenotype in patients with collagen IV nephropathies.
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Affiliation(s)
- Louiza Papazachariou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Panayiota Demosthenous
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Myrtani Pieri
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Gregory Papagregoriou
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Isavella Savva
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | | | - Michael Zavros
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Kyriakos Ioannou
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Alexia Panagides
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | - Costas Potamitis
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Marios Prikis
- Department of Nephrology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Maria Kkolou
- Department of Nephrology, Larnaca General Hospital, Larnaca, Cyprus
| | | | | | - Aristos Michael
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Akis Lazarou
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Maria Arsali
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | - Loukas Damianou
- Department of Nephrology, Limassol General Hospital, Limassol, Cyprus
| | | | | | - Lakis Yioukas
- Department of Nephrology, Paphos General Hospital, Paphos, Cyprus
| | - Avraam Elia
- Department of Pediatrics, Archbishop Makarios III Hospital, Nicosia, Cyprus
| | - Ioanna Zouvani
- Department of Histopathology, Nicosia General Hospital, Nicosia, Cyprus
| | | | - Alkis Pierides
- Department of Nephrology, Hippocrateon Hospital, Nicosia, Cyprus
- * E-mail: (CD); (A. Pierides)
| | - Konstantinos Voskarides
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
| | - Constantinos Deltas
- Molecular Medicine Research Center and Laboratory of Molecular and Medical Genetics, University of Cyprus, Nicosia, Cyprus
- * E-mail: (CD); (A. Pierides)
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30
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Miner JH, Baigent C, Flinter F, Gross O, Judge P, Kashtan CE, Lagas S, Savige J, Blatt D, Ding J, Gale DP, Midgley JP, Povey S, Prunotto M, Renault D, Skelding J, Turner AN, Gear S. The 2014International Workshop on Alport Syndrome. Kidney Int 2014; 86:679-84. [PMID: 24988067 PMCID: PMC4182137 DOI: 10.1038/ki.2014.229] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 03/24/2014] [Accepted: 04/01/2014] [Indexed: 01/15/2023]
Abstract
Alport syndrome, historically referred to as hereditary glomerulonephritis with sensorineural deafness and anterior lenticonus, is a genetic disease of collagen α3α4α5(IV) resulting in renal failure. The collagen α3α4α5(IV) heterotrimer forms a network that is a major component of the kidney glomerular basement membrane (GBM) and basement membranes in the cochlea and eye. Alport syndrome, estimated to affect 1 in 5000–10,000 individuals, is caused by mutations in any one of the three genes that encode the α chain components of the collagen α3α4α5(IV) heterotrimer: COL4A3, COL4A4, and COL4A5. Although angiotensin-converting enzyme inhibition is effective in Alport syndrome patients for slowing progression to end-stage renal disease, it is neither a cure nor an adequate long-term protector. The 2014 International Workshop on Alport Syndrome, held in Oxford, UK, from January 3–5, was organized by individuals and families living with Alport syndrome, in concert with international experts in the clinical, genetic, and basic science aspects of the disease. Stakeholders from diverse communities—patient families, physicians, geneticists, researchers, Pharma, and funding organizations—were brought together so that they could meet and learn from each other and establish strategies and collaborations for the future, with the overall aim of discovering much needed new treatments to prolong kidney function.
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Affiliation(s)
- Jeffrey H Miner
- Renal Division, Washington University School of Medicine, St Louis, Missouri, USA
| | - Colin Baigent
- Clinical Trial Service Unit and Epidemiological Studies Unit, University of Oxford, Oxford, UK
| | - Frances Flinter
- Department of Clinical Genetics, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medicine Goettingen, Goettingen, Germany
| | - Parminder Judge
- Clinical Trial Service Unit and Epidemiological Studies Unit, University of Oxford, Oxford, UK
| | - Clifford E Kashtan
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Sharon Lagas
- Alport Syndrome Foundation, Phoenix, Arizona, USA
| | - Judith Savige
- Melbourne Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Dave Blatt
- Alport Foundation of Australia, Valentine, New South Wales, Australia
| | - Jie Ding
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Daniel P Gale
- University College London-Center for Nephrology, London, UK
| | - Julian P Midgley
- Department of Pediatrics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Sue Povey
- Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Marco Prunotto
- Discovery Technology Department, Pharma Research and Early Development, Basel, Switzerland
| | - Daniel Renault
- Association for Information and Research on Genetic Renal Diseases (AIRG)-France, Paris, France
| | | | - A Neil Turner
- Renal Medicine, Royal Infirmary, University of Edinburgh, Edinburgh, UK
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