1
|
Finn LS. Nephrotic Syndrome Throughout Childhood: Diagnosing Podocytopathies From the Womb to the Dorm. Pediatr Dev Pathol 2024:10935266241242669. [PMID: 38745407 DOI: 10.1177/10935266241242669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The etiologies of podocyte dysfunction that lead to pediatric nephrotic syndrome (NS) are vast and vary with age at presentation. The discovery of numerous novel genetic podocytopathies and the evolution of diagnostic technologies has transformed the investigation of steroid-resistant NS while simultaneously promoting the replacement of traditional morphology-based disease classifications with a mechanistic approach. Podocytopathies associated with primary and secondary steroid-resistant NS manifest as diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, and collapsing glomerulopathy. Molecular testing, once an ancillary option, has become a vital component of the clinical investigation and when paired with kidney biopsy findings, provides data that can optimize treatment and prognosis. This review focuses on the causes including selected monogenic defects, clinical phenotypes, histopathologic findings, and age-appropriate differential diagnoses of nephrotic syndrome in the pediatric population with an emphasis on podocytopathies.
Collapse
Affiliation(s)
- Laura S Finn
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at The University of Pennsylvania, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| |
Collapse
|
2
|
Kuzmuk V, Pranke I, Rollason R, Butler M, Ding WY, Beesley M, Waters AM, Coward RJ, Sessions R, Tuffin J, Foster RR, Mollet G, Antignac C, Edelman A, Welsh GI, Saleem MA. A small molecule chaperone rescues keratin-8 mediated trafficking of misfolded podocin to correct genetic Nephrotic Syndrome. Kidney Int 2024; 105:744-758. [PMID: 37995908 DOI: 10.1016/j.kint.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 10/02/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023]
Abstract
Podocin is a key membrane scaffolding protein of the kidney podocyte essential for intact glomerular filtration. Mutations in NPHS2, the podocin-encoding gene, represent the commonest form of inherited nephrotic syndrome (NS), with early, intractable kidney failure. The most frequent podocin gene mutation in European children is R138Q, causing retention of the misfolded protein in the endoplasmic reticulum. Here, we provide evidence that podocin R138Q (but not wild-type podocin) complexes with the intermediate filament protein keratin 8 (K8) thereby preventing its correct trafficking to the plasma membrane. We have also identified a small molecule (c407), a compound that corrects the Cystic Fibrosis Transmembrane Conductance Regulator protein defect, that interrupts this complex and rescues mutant protein mistrafficking. This results in both the correct localization of podocin at the plasma membrane and functional rescue in both human patient R138Q mutant podocyte cell lines, and in a mouse inducible knock-in model of the R138Q mutation. Importantly, complete rescue of proteinuria and histological changes was seen when c407 was administered both via osmotic minipumps or delivered orally prior to induction of disease or crucially via osmotic minipump two weeks after disease induction. Thus, our data constitute a therapeutic option for patients with NS bearing a podocin mutation, with implications for other misfolding protein disorders. Further studies are necessary to confirm our findings.
Collapse
Affiliation(s)
- Valeryia Kuzmuk
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Iwona Pranke
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
| | - Ruth Rollason
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Matthew Butler
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Wen Y Ding
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Matthew Beesley
- Department of Pathology, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, UK
| | | | - Richard J Coward
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | | | - Jack Tuffin
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Rebecca R Foster
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Géraldine Mollet
- Laboratoire des Maladies Rénales Héréditaires, Inserm UMR 1163, Institut Imagine, Université Paris Cité, Paris, France
| | - Corinne Antignac
- Laboratoire des Maladies Rénales Héréditaires, Inserm UMR 1163, Institut Imagine, Université Paris Cité, Paris, France
| | | | - Gavin I Welsh
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Moin A Saleem
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK.
| |
Collapse
|
3
|
Gomaraschi M, Turri M, Strazzella A, Lhomme M, Pavanello C, Le Goff W, Kontush A, Calabresi L, Ossoli A. Abnormal Lipoproteins Trigger Oxidative Stress-Mediated Apoptosis of Renal Cells in LCAT Deficiency. Antioxidants (Basel) 2023; 12:1498. [PMID: 37627492 PMCID: PMC10451761 DOI: 10.3390/antiox12081498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/27/2023] Open
Abstract
Familial lecithin:cholesterol acyltransferase (LCAT) deficiency (FLD) is a rare genetic disease caused by the loss of function mutations in the LCAT gene. LCAT deficiency is characterized by an abnormal lipoprotein profile with severe reduction in plasma levels of high-density lipoprotein (HDL) cholesterol and the accumulation of lipoprotein X (LpX). Renal failure is the major cause of morbidity and mortality in FLD patients; the pathogenesis of renal disease is only partly understood, but abnormalities in the lipoprotein profile could play a role in disease onset and progression. Serum and lipoprotein fractions from LCAT deficient carriers and controls were tested for renal toxicity on podocytes and tubular cells, and the underlying mechanisms were investigated at the cellular level. Both LpX and HDL from LCAT-deficient carriers triggered oxidative stress in renal cells, which culminated in cell apoptosis. These effects are partly explained by lipoprotein enrichment in unesterified cholesterol and ceramides, especially in the HDL fraction. Thus, alterations in lipoprotein composition could explain some of the nephrotoxic effects of LCAT deficient lipoproteins on podocytes and tubular cells.
Collapse
Affiliation(s)
- Monica Gomaraschi
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy; (M.G.); (M.T.); (C.P.); (A.O.)
| | - Marta Turri
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy; (M.G.); (M.T.); (C.P.); (A.O.)
| | - Arianna Strazzella
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy; (M.G.); (M.T.); (C.P.); (A.O.)
| | - Marie Lhomme
- Foundation for Innovation in Cardiometabolism and Nutrition (ANR-10-IAHU-05), IHU ICAN (ICAN OMICS and ICAN I/O), 75013 Paris, France;
| | - Chiara Pavanello
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy; (M.G.); (M.T.); (C.P.); (A.O.)
| | - Wilfried Le Goff
- National Institute for Health and Medical Research (INSERM), UMRS 1166 ICAN, Faculty of Medicine Pitié-Salpêtrière, Sorbonne University, 75013 Paris, France; (W.L.G.); (A.K.)
| | - Anatol Kontush
- National Institute for Health and Medical Research (INSERM), UMRS 1166 ICAN, Faculty of Medicine Pitié-Salpêtrière, Sorbonne University, 75013 Paris, France; (W.L.G.); (A.K.)
| | - Laura Calabresi
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy; (M.G.); (M.T.); (C.P.); (A.O.)
| | - Alice Ossoli
- Center E. Grossi Paoletti, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milan, Italy; (M.G.); (M.T.); (C.P.); (A.O.)
| |
Collapse
|
4
|
Kim JE, Jo MJ, Cho E, Ahn SY, Kwon YJ, Gim JA, Ko GJ. The Effect of DNA Methylation in the Development and Progression of Chronic Kidney Disease in the General Population: An Epigenome-Wide Association Study Using the Korean Genome and Epidemiology Study Database. Genes (Basel) 2023; 14:1489. [PMID: 37510393 PMCID: PMC10379047 DOI: 10.3390/genes14071489] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
BACKGROUND Although knowledge of the genetic factors influencing kidney disease is increasing, epigenetic profiles, which are associated with chronic kidney disease (CKD), have not been fully elucidated. We sought to identify the DNA methylation status of CpG sites associated with reduced kidney function and examine whether the identified CpG sites are associated with CKD development. METHOD We analyzed DNA methylation patterns of 440 participants in the Korean Genome and Epidemiology Study (KoGES) with estimated glomerular filtration rates (eGFRs) ≥ 60 mL/min/1.73 m2 at baseline. CKD development was defined as a decrease in the eGFR of <60 at any time during an 8-year follow-up period ("CKD prediction" analysis). In addition, among the 440 participants, 49 participants who underwent a second methylation profiling were assessed for an association between a decline in kidney function and changes in the degree of methylation of CpG sites during the 8 years ("kidney function slope" analysis). RESULTS In the CKD prediction analysis, methylation profiles of a total of 403,129 CpG sites were evaluated at baseline in 440 participants, and increased and decreased methylation of 268 and 189 CpG sites, respectively, were significantly correlated with the development of CKD in multivariable logistic regression. During kidney function slope analysis using follow-up methylation profiles of 49 participants, the percent methylation changes in 913 CpG sites showed a linear relationship with the percent change in eGFR during 8 years. During functional enrichment analyses for significant CpG sites found in the CKD prediction and kidney function slope analyses, we found that those CpG sites represented MAPK, PI3K/Akt, and Rap1 pathways. In addition, three CpG sites from three genes, NPHS2, CHCHD4, and AHR, were found to be significant in the CKD prediction analysis and related to a decline in kidney function. CONCLUSION It is suggested that DNA methylation on specific genes is associated with the development of CKD and the deterioration of kidney function.
Collapse
Affiliation(s)
- Ji-Eun Kim
- Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| | - Min-Jee Jo
- Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| | - Eunjung Cho
- Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| | - Shin-Young Ahn
- Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| | - Young-Joo Kwon
- Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| | - Jeong-An Gim
- Medical Science Research Center, Korea University College of Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| | - Gang-Jee Ko
- Department of Internal Medicine, Korea University Guro Hospital, Seoul 08308, Republic of Korea
| |
Collapse
|
5
|
Al-Azzawy MF, Al-Haggar M, ElSaid AM, El-Khawaga OY. Analysis of the association of NPHS2 and ACTN4 genes polymorphism with nephrotic syndrome in Egyptian children. Mol Biol Rep 2023; 50:4481-4490. [PMID: 37014572 PMCID: PMC10147774 DOI: 10.1007/s11033-023-08387-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/14/2023] [Indexed: 04/05/2023]
Abstract
BACKGROUND One of the most common kidney illnesses in developing countries is pediatric nephrotic syndrome (PNS), which is frequently associated with dyslipidemia and edema. The rapid discovery of genes related to NS has aided in the understanding of the molecular mechanics of glomerular filtration. The goal of this study is to determine the relationship between NPHS2 and ACTN4 in PNS youngsters. METHODS A study with 100 NS children and 100 healthy matched volunteers was conducted. Genomic DNA was extracted from peripheral blood. Single-nucleotide polymorphisms were genotyped using ARMS-PCR. RESULTS A substantial decline in the level of albumin was found in NS cases (P < 0.001) Further on, a significantly difference in T.C and TG level between healthy and NS patient. Molecular study showed a highly significant difference of NS patients from controls regarding NPHS2 rs3829795 polymorphic genotypes as the GA heterozygous genotype shows highly significant difference from controls (P < 0.001) as well as GA + AA genotypes (P < 0.001) in comparison with GG genotype. Regarding rs2274625, The GA heterozygous genotype showed no statistically significant difference between genotypes and alleles with NS (P = 0.246). Association of AG haplotype NPHS2 rs3829795-rs2274625 haplotypes found a significant association with the risk of developing NS (P = 0.008). Concerning the ACTN4 rs121908415 SNP, there was no link between this mutation and NS children. CONCLUSION The correlation of AG haplotype NPHS2 rs3829795-rs2274625 haplotypes identified a strong association with the likelihood of getting NS, according to our findings. There was no connection found between the ACTN4 rs121908415 SNP and NS children.
Collapse
Affiliation(s)
- Mohammed F Al-Azzawy
- Biochemistry Division, Chemistry Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Mohammad Al-Haggar
- Genetic Unit, Department of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Afaf M ElSaid
- Genetic Unit, Department of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Omali Y El-Khawaga
- Biochemistry Division, Chemistry Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt.
| |
Collapse
|
6
|
Alhusaini AM, Alhumaidan SA, Alharbi GM, Alzahrani EA, Sarawi WS, Alomar HA, Alanazi AM, Mattar DS, Hasan IH. Cross-Regulation between Autophagy and Apoptosis Induced by Vitamin E and Lactobacillus Plantarum through Beclin-1 Network. Int J Mol Sci 2022; 23:ijms232315305. [PMID: 36499631 PMCID: PMC9736033 DOI: 10.3390/ijms232315305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/30/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Autophagy and apoptosis are two important regulatory mechanisms for how the body can respond to diseases. This study was designed to investigate the protective actions of vitamin E (Vit-E) and lactobacillus plantarum (Lac-B) against mercuric chloride (HgCl2)-induced kidney injury. Thirty albino rats were divided into five groups: group 1 served as the normal group; rats in group 2 received high doses of HgCl2; rats in groups 3, 4 and 5 were given Vit-E, Lac-B and the combination of Vit-E and Lac-B, respectively along with HgCl2 for two weeks. HgCl2 provoked renal injury, manifested by elevation in serum urea, urea nitrogen and creatinine. Kidney levels of oxidative stress and inflammation were markedly increased post HgCl2 administration. Moreover, HgCl2 significantly elevated the gene expression levels of VCAM-1 and cystatin C, while podocin was downregulated. Additionally, it markedly decreased the protein expression of Beclin-1 and Bcl-2. Histopathological examination revealed massive degeneration with congested blood vessels following HgCl2 administration. Treatment with Vit-E or/and Lac-B restored the normal levels of the previously mentioned parameters, as well as improved the morphology of kidney tissues. Both Vit-E and Lac-B provided a protective effect against HgCl2-induced kidney damage by regulating autophagy and apoptosis.
Collapse
Affiliation(s)
- Ahlam M. Alhusaini
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
- Correspondence: (A.M.A.); (I.H.H.)
| | - Sara A. Alhumaidan
- College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
| | - Ghaida M. Alharbi
- College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
| | - Eman A. Alzahrani
- College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
| | - Wedad S. Sarawi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
| | - Hatun A. Alomar
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
| | - Abeer M. Alanazi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
| | - Dareen S. Mattar
- Department of Physiology, College of Medicine, Umm Al Qura University, P.O. Box 715, Makkah 21955, Saudi Arabia
| | - Iman H. Hasan
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia
- Correspondence: (A.M.A.); (I.H.H.)
| |
Collapse
|
7
|
Jankowski M, Daca-Roszak P, Obracht-Prondzyński C, Płoski R, Lipska-Ziętkiewicz BS, Ziętkiewicz E. Genetic diversity in Kashubs: the regional increase in the frequency of several disease-causing variants. J Appl Genet 2022; 63:691-701. [PMID: 35971028 PMCID: PMC9637066 DOI: 10.1007/s13353-022-00713-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 07/12/2022] [Accepted: 07/18/2022] [Indexed: 12/02/2022]
Abstract
Differential distribution of genetic variants’ frequency among human populations is caused by the genetic drift in isolated populations, historical migrations, and demography. Some of these variants are identical by descent and represent founder mutations, which — if pathogenic in nature — lead to the increased frequency of otherwise rare diseases. The detection of the increased regional prevalence of pathogenic variants may shed light on the historical processes that affected studied populations and can help to develop effective screening and diagnostic strategies as a part of personalized medicine. Here, we discuss the specific genetic diversity in Kashubs, the minority group living in northern Poland, reflected in the biased distribution of some of the repetitively found disease-causing variants. These include the following: (1) c.662A > G (p.Asp221Gly) in LDLR, causing heterozygous familial hypercholesterolemia; (2) c.3700_3704del in BRCA1, associated with hereditary breast and ovarian cancer syndrome; (3) c.1528G > C (p.Glu510Gln) in HADHA, seen in long-chain 3-hydroxy acyl-CoA dehydrogenase (LCHAD) deficiency, and (4) c.1032delT in NPHS2, associated with steroid-resistant nephrotic syndrome.
Collapse
Affiliation(s)
- Maciej Jankowski
- Department of Biology and Medical Genetics, Medical University of Gdansk, Gdansk, Poland
| | | | | | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Beata S Lipska-Ziętkiewicz
- Clinical Genetics Unit, Department of Biology and Medical Genetics, Medical University of Gdansk, Gdansk, Poland. .,Centre for Rare Diseases, Medical University of Gdansk, Gdansk, Poland.
| | - Ewa Ziętkiewicz
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland.
| |
Collapse
|
8
|
Jin B, Zhu J, Zhou Y, Liang L, Yang Y, Xu L, Zhang T, Li P, Pan T, Guo B, Chen T, Li H. Loss of MEN1 leads to renal fibrosis and decreases HGF-Adamts5 pathway activity via an epigenetic mechanism. Clin Transl Med 2022; 12:e982. [PMID: 35968938 PMCID: PMC9377152 DOI: 10.1002/ctm2.982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 06/28/2022] [Accepted: 07/03/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Renal fibrosis is a serious condition that results in the development of chronic kidney diseases. The MEN1 gene is an epigenetic regulator that encodes the menin protein and its role in kidney tissue remains unclear. METHODS Kidney histology was examined on paraffin sections stained with hematoxylin-eosin staining. Masson's trichrome staining and Sirius red staining were used to analyze renal fibrosis. Gene and protein expression were determined by quantitative real-time PCR (qPCR) and Western blot, respectively. Immunohistochemistry staining in the kidney tissues from mice or patients was used to evaluate protein levels. Flow cytometry was used to analyze the cell cycle distributions and apoptosis. RNA-sequencing was performed for differential expression genes in the kidney tissues of the Men1f/f and Men1∆/∆ mice. Chromatin immunoprecipitation sequencing (ChIP-seq) was carried out for identification of menin- and H3K4me3-enriched regions within the whole genome in the mouse kidney tissue. ChIP-qPCR assays were performed for occupancy of menin and H3K4me3 at the gene promoter regions. Luciferase reporter assay was used to detect the promoter activity. The exacerbated unilateral ureteral obstruction (UUO) models in the Men1f/f and Men1∆/∆ mice were used to assess the pharmacological effects of rh-HGF on renal fibrosis. RESULTS The expression of MEN1 is reduce in kidney tissues of fibrotic mouse and human diabetic patients and treatment with fibrotic factor results in the downregulation of MEN1 expression in renal tubular epithelial cells (RTECs). Disruption of MEN1 in RTECs leads to high expression of α-SMA and Collagen 1, whereas MEN1 overexpression restrains epithelial-to-mesenchymal transition (EMT) induced by TGF-β treatment. Conditional knockout of MEN1 resulted in chronic renal fibrosis and UUO-induced tubulointerstitial fibrosis (TIF), which is associated with an increased induction of EMT, G2/M arrest and JNK signaling. Mechanistically, menin recruits and increases H3K4me3 at the promoter regions of hepatocyte growth factor (HGF) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (Adamts5) genes and enhances their transcriptional activation. In the UUO mice model, exogenous HGF restored the expression of Adamts5 and ameliorated renal fibrosis induced by Men1 deficiency. CONCLUSIONS These findings demonstrate that MEN1 is an essential antifibrotic factor in renal fibrogenesis and could be a potential target for antifibrotic therapy.
Collapse
Affiliation(s)
- Bangming Jin
- Department of SurgeryAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
- Guizhou Institute of Precision MedicineAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
| | - Jiamei Zhu
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Yuxia Zhou
- Department of SurgeryAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
| | - Li Liang
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Yunqiao Yang
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Lifen Xu
- Department of SurgeryAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Tuo Zhang
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Po Li
- Department of SurgeryAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
| | - Ting Pan
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Bing Guo
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
| | - Tengxiang Chen
- Department of SurgeryAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
- School of Basic Medical SciencesGuizhou Medical UniversityGuiyangChina
- Transformation Engineering Research Center of Chronic Disease Diagnosis and TreatmentGuizhou Medical UniversityGuiyangChina
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic DiseasesGuizhou Medical UniversityGuiyangChina
- Guizhou Institute of Precision MedicineAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
| | - Haiyang Li
- Department of SurgeryAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
- Guizhou Institute of Precision MedicineAffiliated Hospital of Guizhou Medical UniversityGuiyangChina
| |
Collapse
|
9
|
Lu L, Yap Y, Nguyen DQ, Chan Y, Ng J, Zhang Y, Chan C, Than M, Liu ID, Asim S, Moorani K, Naeem B, Ijaz I, Nguyen TMT, Lee M, Eng C, Huque SS, Ng Y, Ganesan I, Chao S, Chong S, Tan P, Loh A, Davila S, Kumar V, Ling JZ, Moorakonda RB, Tan KM, Ng AY, Poon K, Schaefer F, Lipska‐Zietkiewicz B, Yap H, Ng K. Multicenter Study on the Genetics of Glomerular Diseases among Southeast and South Asians: The
DRAGoN
Study. Clin Genet 2022; 101:541-551. [DOI: 10.1111/cge.14116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 01/10/2022] [Accepted: 01/19/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Liangjian Lu
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
| | | | | | | | - Jun‐Li Ng
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
- Paediatrics National University of Singapore Singapore
| | - Yao‐Chun Zhang
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
- Paediatrics National University of Singapore Singapore
| | - Chang‐Yien Chan
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
- Paediatrics National University of Singapore Singapore
| | - Mya Than
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
- Paediatrics National University of Singapore Singapore
| | - Isaac Desheng Liu
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
| | - Sadaf Asim
- Paediatric Nephrology National Institute of Child Health Pakistan
| | | | - Bilquis Naeem
- Paediatric Nephrology National Institute of Child Health Pakistan
| | | | | | | | | | - Syed Saimul Huque
- Paediatric Nephrology Bangabandhu Sheikh Mujib Medical University Bangladesh
| | | | | | | | | | - Puay‐Hoon Tan
- Anatomical Pathology Singapore General Hospital Singapore
| | - Alwin Loh
- Anatomical Pathology Singapore General Hospital Singapore
| | - Sonia Davila
- Institute of Precision Medicine Duke‐NUS Singapore
| | | | | | | | | | - Alvin Yu‐Jin Ng
- Molecular Diagnosis Centre National University Hospital Singapore
| | - Kok‐Siong Poon
- Molecular Diagnosis Centre National University Hospital Singapore
| | - Franz Schaefer
- Paediatrics Nephrology Center for Paediatrics and Adolescent Medicine Germany
| | | | - Hui‐Kim Yap
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
- Paediatrics National University of Singapore Singapore
| | - Kar‐Hui Ng
- Khoo Teck Puat‐National University Children's Medical Institute National University Health System Singapore
- Paediatrics National University of Singapore Singapore
| | | |
Collapse
|
10
|
Chamgordani LE, Ebrahimi N, Amirmahani F, Vallian S. CG/CA genotypes represent novel markers in the NPHS2 gene region associated with nephrotic syndrome. J Genet 2020. [DOI: 10.1007/s12041-020-1188-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
11
|
Sahu SN, Moharana M, Sahu R, Pattanayak SK. Impact of mutation on podocin protein involved in type 2 nephrotic syndrome: Insights into docking and molecular dynamics simulation study. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
12
|
The Role of p.Ser1105Ser (in NPHS1 Gene) and p.Arg548Leu (in PLCE1 Gene) with Disease Status of Vietnamese Patients with Congenital Nephrotic Syndrome: Benign or Pathogenic? ACTA ACUST UNITED AC 2019; 55:medicina55040102. [PMID: 31013750 PMCID: PMC6524047 DOI: 10.3390/medicina55040102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 11/20/2022]
Abstract
Background and Objectives: Congenital nephrotic syndrome (CNS), a genetic disease caused by mutations in genes on autosomes, usually occurs in the first three months after birth. A number of genetic mutations in genes, which encode for the components of the glomerular filtration barrier have been identified. We investigated mutations in NPHS1, NPHS2, PLCE1 (NPHS3), and WT1 genes that relate to the disease in Vietnamese patients. Materials and Methods: We performed genetic analysis of two unrelated patients, who were diagnosed with CNS in the Vietnam National Children’s Hospital with different disease status. The entire coding region and adjacent splice sites of these genes were amplified and sequenced using the Sanger method. The sequencing data were analyzed and compared with the NPHS1, NPHS2, PLCE1, and WT1 gene sequences published in Ensembl (ENSG00000161270, ENSG00000116218, ENSG00000138193, and ENSG00000184937, respectively) using BioEdit software to detect mutations. Results: We detected a new variant p.Ser607Arg and two other (p.Glu117Lys and p.Ser1105Ser) in the NPHS1 gene, as well as two variants (p.Arg548Leu, p.Pro1575Arg) in the PLCE1 gene. No mutations were detected in the NPHS2 and WT1 genes. Patient 1, who presented a heterozygous genotype of p.Ser1105Ser and p.Arg548Leu had a mild disease status but patient 2, who presented a homozygous genotype of these alleles, had a severe phenotype. Conclusions: These results suggest that variants p.Ser1105Ser (in NPHS1 gene) and p.Arg548Leu (in PLCE1 gene) in the homozygous form might play a role in the development of the disease in patients.
Collapse
|
13
|
Jellouli M, Charfi R, Maalej B, Mahfoud A, Trabelsi S, Gargah T. Rituximab in The Management of Pediatric Steroid-Resistant Nephrotic Syndrome: A Systematic Review. J Pediatr 2018; 197:191-197.e1. [PMID: 29680473 DOI: 10.1016/j.jpeds.2018.01.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/14/2017] [Accepted: 01/02/2018] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To evaluate the efficacy and safety of rituximab in children with steroid-resistant nephrotic syndrome. STUDY DESIGN A systematic review evaluating the efficacy and safety of rituximab in children with steroid-resistant nephrotic syndrome was performed. Data from studies, performed before April 2017 were collected, from MEDLINE, Cochrane Library, Scopus, and Web of Science. Study eligibility criteria included clinical trials and observational studies with a minimal sample size of 5 patients, regarding treatment with rituximab in children with steroid-resistant nephrotic syndrome. Independent extraction of articles by 2 investigators using predefined data fields was performed. RESULTS We included 7 case series and 1 open-label randomized controlled trial. Among them, 3 studies were multicenter. A total of 226 patients were included. Mean age at onset was 5.6 ± 1.1 years. Mean number of rituximab administrations was 3.1 ± 1.1 infusions per patient. Remission was observed in 89 patients (46.4%). Remission was seen in 40.8% patients with initial steroid-resistant nephrotic syndrome and 52.8% patients with late steroid-resistant nephrotic syndrome. Good initial response to rituximab therapy was observed in 63.2% patients with minimal change nephrotic syndrome, 39.2% patients with focal and segmental glomerulosclerosis, 1 patient had diffuse mesangial hypercellularity, and 1 patient had IgM nephropathy. Sustained remission ranged from 18% to 93.7%. Five serious adverse events were observed. CONCLUSIONS Rituximab exhibited a satisfactory profile regarding efficacy and safety indicating that this agent is a promising therapy for steroid-resistant nephrotic syndrome and should be further investigated by randomized clinical trials.
Collapse
Affiliation(s)
- Manel Jellouli
- Department of Pediatric Nephrology, Charles Nicolle Hospital, Faculty of Medicine of Tunis, Tunis El Manar University, Tunis, Tunisia.
| | - Rim Charfi
- Department of Clinical Pharmacology, National Center of Pharmacovigilance, Faculty of Medicine of Tunis, Clinical and Experimental Pharmacology Laboratory LR16SP02, Tunis El Manar University, Tunis, Tunisia
| | - Bayen Maalej
- Department of Pediatrics, Pediatric Emergency and Intensive Care, Hedi Chaker Hospital, Sfax, Tunisia
| | - Abdelmajid Mahfoud
- Department of Pediatrics, Pediatric Emergency and Intensive Care, Hedi Chaker Hospital, Sfax, Tunisia
| | - Sameh Trabelsi
- Department of Clinical Pharmacology, National Center of Pharmacovigilance, Faculty of Medicine of Tunis, Clinical and Experimental Pharmacology Laboratory LR16SP02, Tunis El Manar University, Tunis, Tunisia
| | - Tahar Gargah
- Department of Pediatric Nephrology, Charles Nicolle Hospital, Faculty of Medicine of Tunis, Tunis El Manar University, Tunis, Tunisia
| |
Collapse
|
14
|
Chen JS, Chang LC, Wu CZ, Tseng TL, Lin JA, Lin YF, Cheng CW. Significance of the urokinase-type plasminogen activator and its receptor in the progression of focal segmental glomerulosclerosis in clinical and mouse models. J Biomed Sci 2016; 23:24. [PMID: 26846181 PMCID: PMC4743092 DOI: 10.1186/s12929-016-0242-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/26/2016] [Indexed: 11/14/2022] Open
Abstract
Background suPAR biomarker generally considered a pathogenic factor in FSGS. However, studies have been published that dispute this conclusion. The current study was designed to investigate the roles of uPA and suPAR in FSGS in clinical and mouse models. Methods Clinical subjects including those with biopsy-proven FSGS and MCD were enrolled. To verify the role of uPA in FSGS, Adriamycin was used to induce FSGS in uPA knockout (uPA−/−) and BALB/c (WT) mice. Proteinuria and suPAR, the cleaved/intact forms of the circulating suPAR, and possible proteases involving cleavage of the suPAR were also studied. Results FSGS clinical cases presented significantly higher serum levels of suPAR and Cr and lower serum levels of uPA. In the mice model, the uPA−/− group exhibited faster disease progression and worsening proteinuria than the WT group. In addition, the uPA−/− group had higher plasma suPAR levels, glomerular cell apoptosis, and dysregulation of the Th1/Th2 balance. In an analysis of suPAR variants in FSGS, both the intact and cleaved forms of the suPAR were higher in clinical subjects and the mouse model. However, the process of suPAR cleavage was not mediated by enzymatic activities of the uPA, elastase, or cathepsin G. Conclusions A deficiency of uPA accelerated the progression of Adriamycin-induced mouse FSGS model. Decrease of serum uPA levels may be an indicator of the progression of FSGS in clinical subjects and animal models.
Collapse
Affiliation(s)
- Jin-Shuen Chen
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Section 2, Chenggong Road, Neihu District, Taipei, 114, Taiwan
| | - Li-Chien Chang
- School of Pharmacy, National Defense Medical Center, Taipei, Taiwan
| | - Chung-Ze Wu
- Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Tzu-Ling Tseng
- Biomedical Technology & Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Jui-An Lin
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Xing Street, Taipei, 110, Taiwan
| | - Yuh-Feng Lin
- Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Xing Street, Taipei, 110, Taiwan
| | - Chao-Wen Cheng
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wu-Xing Street, Taipei, 110, Taiwan. .,Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan.
| |
Collapse
|
15
|
Dhandapani MC, Venkatesan V, Rengaswamy NB, Gowrishankar K, Ekambaram S, Sengutavan P, Perumal V. Report of novel genetic variation in NPHS2 gene associated with idiopathic nephrotic syndrome in South Indian children. Clin Exp Nephrol 2016; 21:127-133. [DOI: 10.1007/s10157-016-1237-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/17/2016] [Indexed: 10/22/2022]
|
16
|
Weber S, Büscher AK, Hagmann H, Liebau MC, Heberle C, Ludwig M, Rath S, Alberer M, Beissert A, Zenker M, Hoyer PF, Konrad M, Klein HG, Hoefele J. Dealing with the incidental finding of secondary variants by the example of SRNS patients undergoing targeted next-generation sequencing. Pediatr Nephrol 2016; 31:73-81. [PMID: 26248470 DOI: 10.1007/s00467-015-3167-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 01/15/2023]
Abstract
BACKGROUND Steroid-resistant nephrotic syndrome (SRNS) is a severe cause of progressive renal disease. Genetic forms of SRNS can present with autosomal recessive or autosomal dominant inheritance. Recent studies have identified mutations in multiple podocyte genes responsible for SRNS. Improved sequencing methods (next-generation sequencing, NGS) now promise rapid mutational testing of SRNS genes. METHODS In the present study, a simultaneous screening of ten SRNS genes in 37 SRNS patients was performed by NGS. RESULTS In 38 % of the patients, causative mutations in one SRNS gene were found. In 22 % of the patients, in addition to these mutations, a secondary variant in a different gene was identified. CONCLUSIONS This high incidence of accumulating sequence variants was unexpected but, although they might have modifier effects, the pathogenic potential of these additional sequence variants seems unclear so far. The example of molecular diagnostics by NGS in SRNS patients shows that these new sequencing technologies might provide further insight into molecular pathogenicity in genetic disorders but will also generate results, which will be difficult to interpret and complicate genetic counseling. Although NGS promises more frequent identification of disease-causing mutations, the identification of causative mutations, the interpretation of incidental findings and possible pitfalls might pose problems, which hopefully will decrease by further experience and elucidation of molecular interactions.
Collapse
Affiliation(s)
- Stefanie Weber
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Anja K Büscher
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Henning Hagmann
- Renal Division, Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne, Germany
| | - Max C Liebau
- Renal Division, Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Christian Heberle
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Sabine Rath
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Martin Alberer
- Department of Infectious Diseases and Tropical Medicine, Ludwig-Maximilians University, Munich, Germany
| | - Antje Beissert
- Pediatric Nephrology, University Children's Hospital, Würzburg, Germany
| | - Martin Zenker
- Institute of Human Genetics, University Hospital, Magdeburg, Germany
| | - Peter F Hoyer
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | | | - Hanns-Georg Klein
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany
| | - Julia Hoefele
- Center for Human Genetics and Laboratory Diagnostics Dr. Klein, Dr. Rost and Colleagues, Martinsried, Germany.
| |
Collapse
|
17
|
Ng KH, Heng CK, Khor CC, Yap HK. Genes in FSGS: Diagnostic and Management Strategies in Children. CURRENT PEDIATRICS REPORTS 2015. [DOI: 10.1007/s40124-014-0064-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
18
|
Jain V, Feehally J, Jones G, Robertson L, Nair D, Vasudevan P. Steroid-resistant nephrotic syndrome with mutations in NPHS2 (podocin): report from a three-generation family. Clin Kidney J 2014; 7:303-5. [PMID: 25852895 PMCID: PMC4377750 DOI: 10.1093/ckj/sfu028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 02/28/2014] [Accepted: 02/28/2014] [Indexed: 11/26/2022] Open
Abstract
Genetic causes of steroid-resistant nephrotic syndrome are being increasingly recognized. Mutations in NPHS2, which encodes the glomerular protein podocin, account for up to 17% of sporadic and 40% of familial cases, where they display an autosomal-recessive pattern of inheritance. This report describes a non-consanguineous family with three generations of individuals who are either compound heterozygotes for mutations in NPHS2 or who have inherited a mutation and a non-neutral polymorphism (R229Q). As well as providing an aetiological explanation, identifying pathogenic mutations and considering genotype-phenotype correlations can provide prognostic information and lead to changes in genetic counselling and management.
Collapse
Affiliation(s)
- Vani Jain
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - John Feehally
- Department of Nephrology , Leicester General Hospital, University Hospitals of Leicester , Leicester , UK
| | - Gabriela Jones
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - Lisa Robertson
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - Dheepa Nair
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| | - Pradeep Vasudevan
- Department of Clinical Genetics , Leicester Royal Infirmary, University Hospitals of Leicester , Leicester , UK
| |
Collapse
|
19
|
Schurek EM, Völker LA, Tax J, Lamkemeyer T, Rinschen MM, Ungrue D, Kratz JE, Sirianant L, Kunzelmann K, Chalfie M, Schermer B, Benzing T, Höhne M. A disease-causing mutation illuminates the protein membrane topology of the kidney-expressed prohibitin homology (PHB) domain protein podocin. J Biol Chem 2014; 289:11262-11271. [PMID: 24596097 DOI: 10.1074/jbc.m113.521773] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Mutations in the NPHS2 gene are a major cause of steroid-resistant nephrotic syndrome, a severe human kidney disorder. The NPHS2 gene product podocin is a key component of the slit diaphragm cell junction at the kidney filtration barrier and part of a multiprotein-lipid supercomplex. A similar complex with the podocin ortholog MEC-2 is required for touch sensation in Caenorhabditis elegans. Although podocin and MEC-2 are membrane-associated proteins with a predicted hairpin-like structure and amino and carboxyl termini facing the cytoplasm, this membrane topology has not been convincingly confirmed. One particular mutation that causes kidney disease in humans (podocin(P118L)) has also been identified in C. elegans in genetic screens for touch insensitivity (MEC-2(P134S)). Here we show that both mutant proteins, in contrast to the wild-type variants, are N-glycosylated because of the fact that the mutant C termini project extracellularly. Podocin(P118L) and MEC-2(P134S) did not fractionate in detergent-resistant membrane domains. Moreover, mutant podocin failed to activate the ion channel TRPC6, which is part of the multiprotein-lipid supercomplex, indicative of the fact that cholesterol recruitment to the ion channels, an intrinsic function of both proteins, requires C termini facing the cytoplasmic leaflet of the plasma membrane. Taken together, this study demonstrates that the carboxyl terminus of podocin/MEC-2 has to be placed at the inner leaflet of the plasma membrane to mediate cholesterol binding and contribute to ion channel activity, a prerequisite for mechanosensation and the integrity of the kidney filtration barrier.
Collapse
Affiliation(s)
- Eva-Maria Schurek
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Linus A Völker
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Judit Tax
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Tobias Lamkemeyer
- Cologne Excellence Cluster on Cellular Stress Responses in Ageing-associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Denise Ungrue
- Cologne Excellence Cluster on Cellular Stress Responses in Ageing-associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - John E Kratz
- Department of Biological Sciences, Columbia University, New York, New York 10027-6902, and
| | - Lalida Sirianant
- Department of Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Karl Kunzelmann
- Department of Physiology, University of Regensburg, 93053 Regensburg, Germany
| | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, New York 10027-6902, and
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany,; Cologne Excellence Cluster on Cellular Stress Responses in Ageing-associated Diseases, University of Cologne, 50931 Cologne, Germany,; Systems Biology of Ageing Cologne, University of Cologne, 50931 Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany,; Cologne Excellence Cluster on Cellular Stress Responses in Ageing-associated Diseases, University of Cologne, 50931 Cologne, Germany,; Systems Biology of Ageing Cologne, University of Cologne, 50931 Cologne, Germany,.
| | - Martin Höhne
- Systems Biology of Ageing Cologne, University of Cologne, 50931 Cologne, Germany,; Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
20
|
Sethna CB, Gipson DS. Treatment of FSGS in Children. Adv Chronic Kidney Dis 2014; 21:194-9. [PMID: 24602468 DOI: 10.1053/j.ackd.2014.01.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 01/16/2014] [Indexed: 01/17/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a pathologic condition that represents many disease entities. The goals of therapy are to cure the disease. When this is not possible, the secondary goals are to reduce proteinuria to avoid the complications of nephrotic syndrome and to delay progression of kidney disease. Proteinuria remission is one of the most important independent predictors of kidney survival. Children with FSGS who do not achieve partial or complete remission have a 50% risk of progression to ESRD within 5 years whereas those who enter complete remission have a 5-year kidney survival rate of 90%. Treatment of idiopathic FSGS commonly involves immune-based and nonimmunologic therapy options. This manuscript will review the current state of FSGS therapy for children.
Collapse
|
21
|
May CJ, Saleem M, Welsh GI. Podocyte dedifferentiation: a specialized process for a specialized cell. Front Endocrinol (Lausanne) 2014; 5:148. [PMID: 25324828 PMCID: PMC4181233 DOI: 10.3389/fendo.2014.00148] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/01/2014] [Indexed: 11/13/2022] Open
Abstract
The podocyte is one of the two cell types that contribute to the formation of the glomerular filtration barrier (GFB). It is a highly specialized cell with a unique structure. The key feature of the podocyte is its foot processes that regularly interdigitate. A structure known as the slit diaphragm can be found bridging the interdigitations. This molecular sieve comprises the final layer of the GFB. It is well accepted that the podocyte is the target cell in the pathogenesis of nephrotic syndrome. In nephrotic syndrome, the GFB no longer restricts the passage of macromolecules and protein is lost into the urine. A number of phenotypic and morphological changes are seen in the diseased podocyte and in the literature these have been described as an epithelial-mesenchymal transition (EMT). However, there is a growing appreciation that this term does not accurately describe the changes that are seen. Definitions of type-2 EMT are based on typical epithelial cells. While the podocyte is known as a visceral epithelial cell, it is not a typical epithelial cell. Moreover, podocytes have several features that are more consistent with mesenchymal cells. Therefore, we suggest that the term podocyte disease transformation is more appropriate.
Collapse
Affiliation(s)
- Carl James May
- Academic Renal Unit, University of Bristol, Bristol, UK
- *Correspondence: Carl James May, Academic Renal Unit, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol BS1 3NY, UK e-mail:
| | - Moin Saleem
- Academic Renal Unit, University of Bristol, Bristol, UK
| | | |
Collapse
|
22
|
Bouchireb K, Boyer O, Gribouval O, Nevo F, Huynh-Cong E, Morinière V, Campait R, Ars E, Brackman D, Dantal J, Eckart P, Gigante M, Lipska BS, Liutkus A, Megarbane A, Mohsin N, Ozaltin F, Saleem MA, Schaefer F, Soulami K, Torra R, Garcelon N, Mollet G, Dahan K, Antignac C. NPHS2Mutations in Steroid-Resistant Nephrotic Syndrome: A Mutation Update and the Associated Phenotypic Spectrum. Hum Mutat 2013; 35:178-86. [DOI: 10.1002/humu.22485] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 11/05/2013] [Indexed: 01/10/2023]
Affiliation(s)
- Karim Bouchireb
- Assistance Publique-Hôpitaux de Paris, Service de Néphrologie Pédiatrique; Centre de Référence des Maladies Rénales Héréditaires (MARHEA), Hôpital Necker-Enfants Malades; Paris France
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Olivia Boyer
- Assistance Publique-Hôpitaux de Paris, Service de Néphrologie Pédiatrique; Centre de Référence des Maladies Rénales Héréditaires (MARHEA), Hôpital Necker-Enfants Malades; Paris France
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Olivier Gribouval
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Fabien Nevo
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Evelyne Huynh-Cong
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Vincent Morinière
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
| | - Raphaëlle Campait
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
| | - Elisabet Ars
- Molecular Biology Laboratory; Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III; Barcelona Spain
| | - Damien Brackman
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
| | - Jacques Dantal
- Service de Néphrologie et Immunologie Clinique; ITERT, CHU Hôtel Dieu; Nantes France
| | | | - Maddalena Gigante
- Department of Medical and Surgical Sciences; University of Foggia; Foggia Italy
| | - Beata S. Lipska
- Department of Biology and Genetics; Medical University of Gdansk; Gdansk 80-211 Poland
| | - Aurélia Liutkus
- Service de Néphrologie et Rhumatologie Pédiatriques; Centre de référence des Maladies Rénales Rares, Hôpital Femme Mère Enfant; Bron France
| | - André Megarbane
- Unité de Génétique Médicale, Faculté de Médecine; Université Saint Joseph; Beirut Lebanon
| | - Nabil Mohsin
- Department of Nephrology; Royal Hospital; Muscat Oman
| | - Fatih Ozaltin
- Nephrogenetics Laboratory, Department of Pediatric Nephrology; Hacettepe University Faculty of Medicine; Ankara Turkey
| | - Moin A. Saleem
- Department of Paediatric Nephrology; Bristol Royal Hospital for Children, Academic Renal Unit, School of Clinical Sciences, University of Bristol; Bristol UK
| | - Franz Schaefer
- PodoNet Consortium; Division of Pediatric Nephrology, Heidelberg University Center for Pediatrics and Adolescent Medicine; Heidelberg Germany
| | - Kenza Soulami
- CHU Ibn Rochd; Service de Néphrologie Dialyse Transplantation; Casablanca Morocco
| | - Roser Torra
- Nephrology Department; Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau (IIB-Sant Pau), Universitat Autònoma de Barcelona, REDinREN, Instituto de Investigación Carlos III; Barcelona Spain
| | - Nicolas Garcelon
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
- Inserm U872; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
| | - Géraldine Mollet
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| | - Karin Dahan
- Centre de Génétique Humaine; Université Catholique de Louvain; Bruxelles Belgique
| | - Corinne Antignac
- Assistance Publique-Hôpitaux de Paris; Département de Génétique, Hôpital Necker-Enfants Malades; Paris France
- Inserm U983; Institut Imagine, Hôpital Necker-Enfants Malades; Paris France
- Université Paris Descartes-Sorbonne Paris Cité; Paris France
| |
Collapse
|
23
|
Fukuyo Y, Nakamura T, Bubenshchikova E, Powell R, Tsuji T, Janknecht R, Obara T. Nephrin and Podocin functions are highly conserved between the zebrafish pronephros and mammalian metanephros. Mol Med Rep 2013; 9:457-65. [PMID: 24337247 PMCID: PMC3896505 DOI: 10.3892/mmr.2013.1844] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 11/22/2013] [Indexed: 01/28/2023] Open
Abstract
The slit diaphragm (SD) is a highly specialized intercellular junction between podocyte foot processes and is crucial in the formation of the filtration barrier in the renal glomeruli. Zebrafish Nephrin and Podocin are important in the formation of the podocyte SD and mutations in NEPHRIN and PODOCIN genes cause human nephrotic syndrome. In the present study, the zebrafish Podocin protein was observed to be predominantly localized in the pronephric glomerular podocytes, as previously reported for Nephrin. To understand the function of Podocin and Nephrin in zebrafish, splice-blocking morpholino antisense oligonucleotides were used. Knockdown of Podocin or Nephrin by this method induced pronephric glomerular hypoplasia with pericardial edema. Human NEPHRIN and PODOCIN mRNA rescued this glomerular phenotype, however, the efficacy of the rescues was greatly reduced when mRNA-encoding human disease-causing NEPHRIN-R1109X and PODOCIN-R138Q were used. Furthermore, an association between zebrafish Nephrin and Podocin proteins was observed. Notably, Podocin-R150Q, corresponding to human PODOCIN-R138Q, markedly interacted with NEPHRIN compared with wild-type PODOCIN, suggesting that this strong binding capacity of mutated PODOCIN impairs the transport of NEPHRIN and PODOCIN out of the endoplasmic reticulum. The results suggest that the functions of Nephrin and Podocin are highly conserved between the zebrafish pronephros and mammalian metanephros. Accordingly, the zebrafish pronephros may provide a useful tool for analyzing disease-causing gene mutations in human kidney disorders.
Collapse
Affiliation(s)
- Yayoi Fukuyo
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Tomomi Nakamura
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Ekaterina Bubenshchikova
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Rebecca Powell
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Takashi Tsuji
- Department of Biological Science and Technology, Graduate School of Industrial Science and Technology, Tokyo University of Science, Noda, Chiba 278‑8510, Japan
| | - Ralf Janknecht
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Tomoko Obara
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| |
Collapse
|
24
|
Lombel RM, Hodson EM, Gipson DS. Treatment of steroid-resistant nephrotic syndrome in children: new guidelines from KDIGO. Pediatr Nephrol 2013; 28:409-14. [PMID: 23052648 DOI: 10.1007/s00467-012-2304-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 07/30/2012] [Accepted: 08/21/2012] [Indexed: 11/28/2022]
Abstract
Kidney Disease: Improving Global Outcomes (KDIGO) recently published the clinical practice guideline on glomerulonephritis (GN) to assist the practitioner caring for patients with GN. Chapter 4 of the guideline focuses on managing children aged 1-18 years with steroid-resistant nephrotic syndrome (SRNS), defined by an inability to achieve complete remission with corticosteroid therapy. Guideline development followed a thorough evidence review, and management recommendations and suggestions were based on the best available evidence. Limitations of the evidence, including the paucity of large-scale randomized controlled trials, are discussed. This article provides both the guideline recommendations and a brief review of relevant treatment trials related to each recommendation. This précis serves as a summary of the complete guidelines recently published.
Collapse
Affiliation(s)
- Rebecca M Lombel
- Division of Nephrology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA.
| | | | | | | |
Collapse
|
25
|
|
26
|
|
27
|
Progress in pathogenesis of proteinuria. Int J Nephrol 2012; 2012:314251. [PMID: 22693670 PMCID: PMC3368192 DOI: 10.1155/2012/314251] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 03/24/2012] [Accepted: 03/26/2012] [Indexed: 02/06/2023] Open
Abstract
Aims. Proteinuria not only is a sign of kidney damage, but also is involved in the progression of renal diseases as an independent pathologic factor. Clinically, glomerular proteinuria is most commonly observed, which relates to structural and functional anomalies in the glomerular filtration barrier. The aim of this paper was to describe the pathogenesis of glomerular proteinuria. Data Sources. Articles on glomerular proteinuria retrieved from Pubmed and MEDLINE in the recent 5 years were reviewed. Results. The new understanding of the roles of glomerular endothelial cells and the glomerular basement membrane (GBM) in the pathogenesis of glomerular proteinuria was gained. The close relationships of slit diaphragm (SD) molecules such as nephrin, podocin, CD2-associated protein (CD2AP), a-actinin-4, transient receptor potential cation channel 6 (TRPC6), Densin and membrane-associated guanylate kinase inverted 1 (MAGI-1), α3β1 integrin, WT1, phospholipase C epsilon-1 (PLCE1), Lmx1b, and MYH9, and mitochondrial disorders and circulating factors in the pathogenesis of glomerular proteinuria were also gradually discovered. Conclusion. Renal proteinuria is a manifestation of glomerular filtration barrier dysfunction. Not only glomerular endothelial cells and GBM, but also the glomerular podocytes and their SDs play an important role in the pathogenesis of glomerular proteinuria.
Collapse
|
28
|
Magnasco A, Ravani P, Edefonti A, Murer L, Ghio L, Belingheri M, Benetti E, Murtas C, Messina G, Massella L, Porcellini MG, Montagna M, Regazzi M, Scolari F, Ghiggeri GM. Rituximab in children with resistant idiopathic nephrotic syndrome. J Am Soc Nephrol 2012; 23:1117-24. [PMID: 22581994 DOI: 10.1681/asn.2011080775] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Idiopathic nephrotic syndrome resistant to standard treatments remains a therapeutic dilemma in pediatric nephrology. To test whether the anti-CD20 monoclonal antibody rituximab may benefit these patients, we conducted an open-label, randomized, controlled trial in 31 children with idiopathic nephrotic syndrome unresponsive to the combination of calcineurin inhibitors and prednisone. All children continued prednisone and calcineurin inhibitors at the doses prescribed before enrollment, and one treatment group received two doses of rituximab (375 mg/m(2) intravenously) as add-on therapy. The mean age was 8 years (range, 2-16 years). Rituximab did not reduce proteinuria at 3 months (change, -12% [95% confidence interval, -73% to 110%]; P=0.77 in analysis of covariance model adjusted for baseline proteinuria). Additional adjustment for previous remission and interaction terms (treatment by baseline proteinuria and treatment by previous remission) did not change the results. In conclusion, these data do not support the addition of rituximab to prednisone and calcineurin inhibitors in children with resistant idiopathic nephrotic syndrome.
Collapse
Affiliation(s)
- Alberto Magnasco
- Division of Nephrology, Dialysis and Transplantation and Laboratory on Pathophysiology of Uremia, Istituto G. Gaslini, Largo G. Gaslini 5, Genoa, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Gonzalez E, Ettenger R, Rianthavorn P, Tsai E, Malekzadeh M. Preemptive plasmapheresis and recurrence of focal segmental glomerulosclerosis in pediatric renal transplantation. Pediatr Transplant 2011; 15:495-501. [PMID: 21338460 DOI: 10.1111/j.1399-3046.2011.01478.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
FSGS has a high recurrence rate after renal transplantation. To examine the effects of the use of preemptive and post-transplant PP on recurrence and graft outcome, we conducted a retrospective study on 34 pediatric patients (mean age 13±5 yr) with biopsy-proven pretransplant FSGS and who underwent a renal transplantation between 1996 and 2007. Recurrence was defined as a serum albumin level of <3.0g/L in the presence of nephrotic-range proteinuria (>40mg/m(2) /h). Total response to PP therapy was defined as the resolution of the nephrotic-range proteinuria and partial response as persistent proteinuria despite PP but not in the nephrotic range. Fifteen patients received a LD renal transplantation and 19 patients received a DD renal transplantation. Nineteen patients received CsA and 14 patients received tacrolimus. Nineteen patients (56%) had FSGS recurrence. There was no difference in the recurrence rate between patients receiving CsA vs. tacrolimus. Among the 15 LD patients, 13 received preemptive PP (1-10 sessions) and seven patients (47%) had subsequent FSGS recurrence. Among the 19 DD patients, four received preemptive PP and 12 (63%) had FSGS recurrence. The number of preemptive PP did not affect the recurrence rate. In a group of patients with a previous graft loss secondary to recurrence, the rate of recurrence was lower than expected (40%) and two of the three patients who did not recur had three or more sessions of preemptive PP. Of the 19 patients with recurrence, 17 were treated with PP therapy and 88% of the patients fully or partially responded. Only five patients had graft loss at three yr post-transplant: two from FSGS recurrence and three from non-compliance. These results suggest that preemptive PP does not decrease the rate of recurrence after transplantation but might be beneficial in treating high-risk patients with documented recurrence. Patients with FSGS recurrence post-transplant can achieve good graft survival with both LD and DD transplantation.
Collapse
Affiliation(s)
- Elsa Gonzalez
- Department of Pediatrics, Mattel Children's Hospital UCLA, Los Angeles, CA 90095-1752, USA.
| | | | | | | | | |
Collapse
|
30
|
Bertelli R, Bodria M, Nobile M, Alloisio S, Barbieri R, Montobbio G, Patrone P, Ghiggeri GM. Regulation of innate immunity by the nucleotide pathway in children with idiopathic nephrotic syndrome. Clin Exp Immunol 2011; 166:55-63. [PMID: 21762125 DOI: 10.1111/j.1365-2249.2011.04441.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Activation of the oxidative burst and failure of CD4(+) CD25(+) cell regulation have been implicated in idiopathic nephrotic syndrome (iNS). The intimate mechanism is, however, unknown and requires specifically focused studies. We investigated reactive oxygen species (ROS) generation [di-chlorofluorescein-diacetate (DCFDA)] fluorescence assay and the regulatory adenosine 5'-triphosphate (ATP) pathways in the blood of 41 children with iNS, utilizing several agonists and antagonists of nucleotide/nucleoside receptors, including the addition of soluble apyrase. The CD4(+) CD25(+) CD39(+) /CD73(+) expression was determined in vivo in parallel during disease activity. Overall, we found that the percentage of CD39(+) CD4(+) CD25(+) was reduced markedly in iNS by 80% (3·43±0·04% versus 13·14±0·07% of total lymphocytes, P<0·001). In these patients, reactive oxygen species (ROS) generation by polymorphonuclear neutrophils (PMN) at rest was a function of apyrase (CD39) expressed by CD4(+) CD25(+) , with higher rates in patients with very low CD39(+) CD4(+) CD25(+) levels (<7·5%). Addition of apyrase reduced ROS generation by 40% in both iNS and controls and was mainly effective in patients. The quota of ROS surviving ATP elimination was higher still in iNS. In vitro studies to limit ROS generation with adenosine analogues (2'-chloroadenosine and 5'-N-ethylcarboxamidoadenosine) produced minor effects. At variance, antagonizing ATP efflux with carbenoxolone or by antagonizing ATP effects (Brilliant Blue G, KN62 and A437089) reduced ROS generation comparable to apyrase. These results confirm a key role of ATP in the regulation of innate immunity and minimize the effect of adenosine. Decreased CD39(+) CD4(+) CD25(+) expression in iNS highlights an impairment of ATP degradation in this pathology. However, high ROS surviving ATP consumption implies a major role of other regulatory pathways.
Collapse
Affiliation(s)
- R Bertelli
- Division of Nephrology, Dialysis, Transplantation and Laboratory on Pathophysiology of Uremia Division of Anesthesiology, Istituto Giannina Gaslini IRCCS, Genova, Italy
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Piscione TD, Licht C. Genetics of proteinuria: an overview of gene mutations associated with nonsyndromic proteinuric glomerulopathies. Adv Chronic Kidney Dis 2011; 18:273-89. [PMID: 21782134 DOI: 10.1053/j.ackd.2011.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 06/02/2011] [Accepted: 06/16/2011] [Indexed: 02/08/2023]
Abstract
Heritable causes of proteinuria are rare and account for a relatively small proportion of all cases of proteinuria affecting children and adults. Yet, significant contributions to understanding the mechanistic basis for proteinuria have been made through genetic and molecular analyses of a small group of syndromic and nonsyndromic proteinuric disorders which are caused by mutations encoding structural components of the glomerular filtration barrier. Technological advances in genomic analyses and improved accessibility to mutational screening at clinically approved laboratories have facilitated diagnosis of proteinuria in the clinical setting. From a clinical standpoint, it may be argued that a genetic diagnosis mitigates exposure to potentially ineffective and harmful treatments in instances where a clear genotype-phenotype correlation exists between a specific gene mutation and treatment nonresponsiveness. However, cautious interpretation of risk may be necessitated in cases with phenotypic heterogeneity (eg, variability in clinical or histological presentation). This review summarizes gene mutations which are known to be associated with proteinuric glomerulopathies in children and adults.
Collapse
|
32
|
Jungraithmayr TC, Hofer K, Cochat P, Chernin G, Cortina G, Fargue S, Grimm P, Knueppel T, Kowarsch A, Neuhaus T, Pagel P, Pfeiffer KP, Schäfer F, Schönermarck U, Seeman T, Toenshoff B, Weber S, Winn MP, Zschocke J, Zimmerhackl LB. Screening for NPHS2 mutations may help predict FSGS recurrence after transplantation. J Am Soc Nephrol 2011; 22:579-85. [PMID: 21355056 DOI: 10.1681/asn.2010010029] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Steroid-resistant focal segmental glomerulosclerosis (FSGS) often recurs after renal transplantation. In this international survey, we sought to identify genotype-phenotype correlations of recurrent FSGS. We surveyed 83 patients with childhood-onset primary FSGS who received at least one renal allograft and analyzed 53 of these patients for NPHS2 mutations. The mean age at diagnosis was 6.7 years, and the mean age at first renal transplantation was 13 years. FSGS recurred in 30 patients (36%) after a median of 13 days (range, 1.5 to 152 days). Twenty-three patients received a second kidney transplant, and FSGS recurred in 11 (48%) after a median of 16 days (range, 2.7 to 66 days). None of the 11 patients with homozygous or compound heterozygous NPHS2 mutations developed recurrent FSGS compared with 45% of patients without mutations. These data suggest that genetic testing for pathogenic mutations may be important for prognosis and treatment of FSGS both before and after transplantation.
Collapse
|
33
|
Long-term outcome of focal segmental glomerulosclerosis after pediatric renal transplantation. Pediatr Nephrol 2010; 25:529-34. [PMID: 19956977 DOI: 10.1007/s00467-009-1361-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 09/27/2009] [Accepted: 10/01/2009] [Indexed: 10/20/2022]
Abstract
Recurrence of focal segmental glomerulosclerosis (FSGS) after renal transplantation can limit graft survival. Despite new immunosuppressive agents, the incidence of recurrence remains relatively high. To identify risk factors for recurrence and efficacy of treatment, we reviewed the outcome of 23 grafts in 16 children with FSGS who had undergone transplantation between 1985 and 2007 at La Paz Children's Hospital. Recurrence was 56.3% after the first transplantation. We did not find significant differences in age at diagnosis, age at transplantation, age at end-stage renal disease (ESRD), progression to ESRD, bilateral nephrectomy of native kidneys prior to transplantation, use of induction therapy or of different immunosuppressive regimens between patients with and without recurrence. Plasmapheresis (PP) was carried out in seven of nine patients who had suffered recurrence, achieving remission in six of them. One patient received high doses of cyclosporin (CsA) and plasmapheresis, attaining remission. Graft survival was lower (P = 0.043) in patients with FSGS than in those with other ESRD etiologies (first year 75% vs 91%; fifth year 44% vs 78%). Recurrence of FSGS limited graft survival (first year 66% vs 85%; third year 20% vs 68%) (P = 0.07). In our experience, PP can be effective in treating FSGS recurrence, although its effect on long-term graft survival seems more limited.
Collapse
|
34
|
Abstract
The recent discovery of genes involved in familial forms of nephrotic syndrome represents a break-through in nephrology. To date, 15 genes have been characterized and several new loci have been identified, with a potential for discovery of new genes. Overall, these genes account for a large fraction of familial forms of nephrotic syndrome, but they can also be recognized in 10-20% of sporadic cases. These advances increase diagnostic and therapeutic potentials, but also add higher complexity to the scenario, requiring clear definitions of clinical, histopathological and molecular signatures. In general, genetic forms of nephrotic syndrome are resistant to common therapeutic approaches (that include steroids and calcineurin inhibitors) but, in a few cases, drug response or spontaneous remission suggest a complex pathogenesis. Finally, syndromic variants can be recognized on the basis of the associated extra-renal manifestations. In this educational review, clinical, histological and molecular aspects of various forms of familial nephrotic syndrome have been reviewed in an attempt to define a rational diagnostic approach. The proposed model focuses on practical and economic issues, taking into consideration the impossibility of using genetic testing as starting diagnostic tool. The final objective of this review is to outline a diagnostic flow-chart for clinicians and geneticists and to generate a rational scheme for molecular testing.
Collapse
|
35
|
Molecular genetic analysis of podocyte genes in focal segmental glomerulosclerosis--a review. Eur J Pediatr 2009; 168:1291-304. [PMID: 19562370 PMCID: PMC2745545 DOI: 10.1007/s00431-009-1017-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 06/12/2009] [Indexed: 01/15/2023]
Abstract
This review deals with podocyte proteins that play a significant role in the structure and function of the glomerular filter. Genetic linkage studies has identified several genes involved in the development of nephrotic syndrome and contributed to the understanding of the pathophysiology of glomerular proteinuria and/or focal segmental glomerulosclerosis. Here, we describe already well-characterized genetic diseases due to mutations in nephrin, podocin, CD2AP, alpha-actinin-4, WT1, and laminin beta2 chain, as well as more recently identified genetic abnormalities in TRPC6, phospholipase C epsilon, and the proteins encoded by the mitochondrial genome. In addition, the role of the proteins which have shown to be important for the structure and functions by gene knockout studies in mice, are also discussed. Furthermore, some rare syndromes with glomerular involvement, in which molecular defects have been recently identified, are briefly described. In summary, this review updates the current knowledge of genetic causes of congenital and childhood nephrotic syndrome and provides new insights into mechanisms of glomerular dysfunction.
Collapse
|
36
|
Hellin JL, Bech-Serra JJ, Moctezuma EL, Chocron S, Santin S, Madrid A, Vilalta R, Canals F, Torra R, Meseguer A, Nieto JL. Very Low-Molecular-Mass Fragments of Albumin in the Plasma of Patients With Focal Segmental Glomerulosclerosis. Am J Kidney Dis 2009; 54:871-80. [DOI: 10.1053/j.ajkd.2009.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 07/23/2009] [Indexed: 11/11/2022]
|
37
|
Fan Q, Zhang H, Ding J, Liu S, Miao J, Xing Y, Yu Z, Guan N. R168H and V165X mutant podocin might induce different degrees of podocyte injury via different molecular mechanisms. Genes Cells 2009; 14:1079-90. [PMID: 19674119 DOI: 10.1111/j.1365-2443.2009.01336.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A lot of mutations of podocin, a key protein of podocyte slit diaphragm (SD), have been found both in hereditary and sporadic focal segmental glomeruloscleorosis (FSGS). Nevertheless, the mechanisms of podocyte injury induced by mutant podocins are still unclear. A compound heterozygous podocin mutation was identified in our FSGS patient, leading to a truncated (podocin (V165X)) and a missense mutant protein (podocin (R168H)), respectively. Here, it was explored whether and how both mutant podocins induce podocyte injury in the in vitro cultured podocyte cell line. Our results showed that podocin (R168H) induced more significant podocyte apoptosis and expression changes in more podocyte molecules than podocin (V165X). Podocyte injury caused by the normal localized podocin(V165X) was effectively inhibited by TRPC6 knockdown. The abnormal retention of podocin(R168H) in endoplasmic reticulum (ER) resulted in the mis-localizations of other critical SD molecules nephrin, CD2AP and TRPC6, and significantly up-regulated ER stress markers Bip/grp78, p-PERK and caspase-12. These results implicated that podocin (R168H) and podocin (V165X) induced different degrees of podocyte injury, which might be resulted from different molecular mechanisms. Our findings provided some possible clues for further exploring the pharmacological targets to the proteinuria induced by different mutant podocins.
Collapse
Affiliation(s)
- Qingfeng Fan
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Megremis S, Mitsioni A, Mitsioni AG, Fylaktou I, Kitsiou-Tzelli S, Stefanidis CJ, Kanavakis E, Traeger-Synodinos J. Nucleotide variations in the NPHS2 gene in Greek children with steroid-resistant nephrotic syndrome. Genet Test Mol Biomarkers 2009; 13:249-56. [PMID: 19371226 DOI: 10.1089/gtmb.2008.0083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Mutations in the NPHS2 gene, encoding podocin, are a major cause of autosomal-recessive steroid-resistant nephrotic syndrome (SRNS) in childhood, accounting for up to 30% of sporadic and 20-40% of familial cases. Among 22 Greek children with a clinical diagnosis of SRNS, mutation analysis was performed in all eight NPHS2 gene exons, using denaturing gradient gel electrophoresis and DNA sequencing. The frequency of all nucleotide variations found in patients was also evaluated in 100 unrelated samples (18-30 years) with no known history of nephrotic disease. Three pathogenic genotypes (R138Q/R138Q, R229Q/A295T, and R168H/R168H) accounted for 3/14 (21%) of sporadic patients; the A295T mutation in exon 8 (c.883G>A) is novel and predicted in silico to be pathogenic. Among the familial cases, a single patient was heterozygous for R229Q. Several known polymorphisms were found, including the in cis variants IVS3-46C>T plus IVS3-21C>T, IVS7+7A>G A and exonic variants S96S (c.288C>T), A318A (c.954T>C), and L346L (c.1038A>G), with allele frequencies comparable to those in other populations. A novel substitution (IVS3-17C>T) was found in two related patients, but in no controls. In conclusion, podocin mutations do not appear to be a major cause of SRNS in Greek children, although the study cohort was small. However, NPHS2 gene analysis could still be considered in Greek SRNS patients to support appropriate management. The present study also contributes potentially useful observations for the clinical management of SRNS patients.
Collapse
Affiliation(s)
- Spyridon Megremis
- Medical Genetics, Aghia Sofia Children's Hospital, Athens University, Athens, Greece
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Caridi G, Gigante M, Ravani P, Trivelli A, Barbano G, Scolari F, Dagnino M, Murer L, Murtas C, Edefonti A, Allegri L, Amore A, Coppo R, Emma F, De Palo T, Penza R, Gesualdo L, Ghiggeri GM. Clinical features and long-term outcome of nephrotic syndrome associated with heterozygous NPHS1 and NPHS2 mutations. Clin J Am Soc Nephrol 2009; 4:1065-72. [PMID: 19406966 DOI: 10.2215/cjn.03910808] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND AND OBJECTIVES Mutations in nephrin (NPHS1) and podocin (NPHS2) genes represent a major cause of idiopathic nephrotic syndrome (NS) in children. It is not yet clear whether the presence of a single mutation acts as a modifier of the clinical course of NS. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We reviewed the clinical features of 40 patients with NS associated with heterozygous mutations or variants in NPHS1 (n = 7) or NPHS2 (n = 33). Long-term renal survival probabilities were compared with those of a concurrent cohort with idiopathic NS. RESULTS Patients with a single mutation in NPHS1 received a diagnosis before those with potentially nongenetic NS and had a good response to therapies. Renal function was normal in all cases. For NPHS2, six patients had single heterozygous mutations, six had a p.P20L variant, and 21 had a p.R229Q variant. Age at diagnosis and the response to drugs were comparable in all NS subgroups. Overall, they had similar renal survival probabilities as non-NPHS1/NPHS2 cases (log-rank chi(2) 0.84, P = 0.656) that decreased in presence of resistance to therapy (P < 0.001) and in cases with renal lesions of glomerulosclerosis and IgM deposition (P < 0.001). Cox regression confirmed that the only significant predictor of dialysis was resistance to therapy. CONCLUSIONS Our data indicate that single mutation or variant in NPHS1 and NPHS2 does not modify the outcome of primary NS. These patients should be treated following consolidated schemes and have good chances for a good long-term outcome.
Collapse
Affiliation(s)
- Gianluca Caridi
- Division of Nephrology and Laboratory on Pathophysiology of Uremia Istituto Giannina Gaslini, Genova, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
Congenital nephrotic syndrome (CNS) is a rare kidney disorder characterized by heavy proteinuria, hypoproteinemia, and edema starting soon after birth. The majority of cases are caused by genetic defects in the components of the glomerular filtration barrier, especially nephrin and podocin. CNS may also be a part of a more generalized syndrome or caused by a perinatal infection. Immunosuppressive medication is not helpful in the genetic forms of CNS, and kidney transplantation is the only curative therapy. Before the operation, management of these infants largely depends on the magnitude of proteinuria. In severe cases, daily albumin infusions are required to prevent life-threatening edema. The therapy also includes hypercaloric diet, thyroxin and mineral substitution, prevention of thrombotic episodes, and prompt management of infectious complications. The outcome of CNS patients without major extrarenal manifestations is comparable with other patient groups after kidney transplantation.
Collapse
|
41
|
Köttgen A, Hsu CC, Coresh J, Shuldiner AR, Berthier-Schaad Y, Gambhir TR, Smith MW, Boerwinkle E, Kao WHL. The association of podocin R229Q polymorphism with increased albuminuria or reduced estimated GFR in a large population-based sample of US adults. Am J Kidney Dis 2008; 52:868-75. [PMID: 18499321 PMCID: PMC2597304 DOI: 10.1053/j.ajkd.2008.02.306] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 02/14/2008] [Indexed: 11/11/2022]
Abstract
BACKGROUND Rare mutations in nephrosis 2 (NPHS2), encoding podocin, are found in patients with familial and sporadic steroid-resistant nephrotic syndrome and focal segmental glomerular sclerosis. The objective of this study is to assess the contribution of the commonly reported functional podocin polymorphism R229Q to kidney disease in the population at large and replicate a prior study of an association of R229Q and albuminuria in the general population. STUDY DESIGN Large sample of the Atherosclerosis Risk in Communities (ARIC) Study, a population-based prospective study. SETTING & PARTICIPANTS 4,424 white and 3,746 black middle-aged adults. PREDICTOR Genotype at the R229Q polymorphism in podocin. OUTCOMES Urinary albumin-creatinine ratio (ACR) and decreased estimated glomerular filtration rate (eGFR) as measures of kidney damage/dysfunction. MEASUREMENTS Crude and multivariable adjusted linear and logistic regression models. RESULTS R229Q allele frequencies were 3.7% in 4,424 white and 0.6% in 3,746 black individuals. No significant association of R229Q with increased ACR or decreased eGFR was observed (adjusted odds ratio of ACR > or = 30 mg/g in RQ/QQ versus RR carriers, 1.18; 95% confidence interval, 0.76 to 1.84; adjusted odds ratio of eGFR < 60 mL/min/1.73 m(2) in RQ/QQ versus RR carriers, 1.18; 95% confidence interval, 0.76 to 1.83). As expected, the established kidney disease risk factors hypertension and diabetes mellitus were associated strongly with measures of kidney damage/dysfunction, but the R229Q polymorphism was not associated with an additional increase in kidney disease measures. LIMITATIONS Single measurement of ACR, subsample of all ARIC participants. CONCLUSION No significant association of the relatively rare R229Q variant and ACR or eGFR was found in either white or black individuals. The phenotypic effect of a variant as R229Q would have to be of great magnitude to meaningfully contribute to the risk of kidney disease on a population level. The importance of such variants in the general population, as well as replication studies, can be evaluated best in large community-based studies that allow for accounting of established disease risk factors.
Collapse
|
42
|
Tesař V, Zima T. Recent Progress in the Pathogenesis of Nephrotic Proteinuria. Crit Rev Clin Lab Sci 2008; 45:139-220. [DOI: 10.1080/10408360801934865] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
43
|
Sakallioglu O, Gok F, Kalman S, Gul D, Barutcu H, Cengiz N, Baskin E. Electronic microarray screening of podocin mutations: a single-center study. Int Urol Nephrol 2008; 40:1045-51. [PMID: 18683072 DOI: 10.1007/s11255-008-9426-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Accepted: 06/23/2008] [Indexed: 11/26/2022]
Abstract
BACKGROUND Because of resistance to immunosuppressants in nephrotic syndrome and reduction of proteinuria relapses following renal transplantation, it seems that new horizons have arisen from mutational screening of the podocin gene. The aim of this study was to assess electronic microarray screening of the podocin mutation. METHODS Twelve previously identified podocin mutations were screened by the electronic microarray method in known DNA samples and in patients (aged 5 months-18 years, n = 38) with steroid-resistant primary nephrotic syndrome, isolated proteinuria, end-stage renal disease secondary to idiopathic nephrotic syndrome, and proteinuria relapses following renal transplantation. RESULTS DNA samples previously supplied to define the mutation profile for analysis and which were used as controls were completely and correctly detected by this method. None of the 12 mutations was detected in our patients. The duration of analysis for one mutation, including hybridization, was only 30 min for 38 cases. CONCLUSION Electronic microarray screening for NPHS2 mutations is not only rapid but also accurate. Previous identification of the mutation profile most often encountered in the investigated population is needed, however.
Collapse
Affiliation(s)
- Onur Sakallioglu
- Pediatric Nephrology Unit, Gulhane Military Academy of Medicine, 06018, Etlik, Ankara, Turkey.
| | | | | | | | | | | | | |
Collapse
|
44
|
Hattori M, Akioka Y, Chikamoto H, Kobayashi N, Tsuchiya K, Shimizu M, Kagami S, Tsukaguchi H. Increase of integrin-linked kinase activity in cultured podocytes upon stimulation with plasma from patients with recurrent FSGS. Am J Transplant 2008; 8:1550-6. [PMID: 18557739 DOI: 10.1111/j.1600-6143.2008.02287.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Recurrent focal segmental glomerulosclerosis (FSGS) is a major challenge in the field of transplantation. Integrin-linked kinase (ILK) has emerged as a key mediator of podocyte-glomerular basement membrane (GBM) interactions. To clarify the involvement of plasma factors in FSGS recurrence, we examined the effects of plasma from FSGS patients with or without posttransplant recurrence on cultured podocytes, focusing particularly on ILK activity. Podocytes from a conditionally immortalized mouse podocyte cell line were treated with plasma from 11 FSGS patients, and ILK activity was determined using an immune complex kinase assay. Treatment with plasma from three patients with recurrence induced an increase in ILK activity. In contrast, no increase in ILK activity was observed in cultured podocytes treated with plasma from the remaining three patients with recurrence and five patients without recurrence. Cultured podocytes treated with plasma that induced ILK activity showed alterations of focal contact and detachment from the laminin matrix. In conclusion, this preliminary study provides experimental evidence suggesting the possible presence of circulating toxic factors in the plasma of some patients with recurrent FSGS, which induce an increase in podocyte ILK activity that may lead to the detachment of podocytes from the GBM.
Collapse
Affiliation(s)
- M Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, Tokyo, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Furue T, Hattori M, Tsukaguchi H, Kitamura A, Oomori T, Ogino D, Nakakura H, Ashida A, Miura K, Hisano M, Takahashi K, Chikamoto H, Akioka Y, Sakano T. Clinical features and mutational survey of NPHS2 (podocin) in Japanese children with focal segmental glomerulosclerosis who underwent renal transplantation. Pediatr Transplant 2008; 12:341-6. [PMID: 18208440 DOI: 10.1111/j.1399-3046.2007.00752.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recurrent FSGS is a major challenge in the field of nephrology. To clarify the role of NPHS2 defects in the pathogenesis of FSGS recurrence, we sequenced all eight exons of NPHS2 in 11 Japanese pediatric FSGS patients with or without post-transplant recurrence. All patients had biopsy-proven primary FSGS, had no family history of renal diseases or consanguinity, were steroid-resistant, and received living-related renal transplantation. The mean age at onset was 5.0 +/- 3.1 yr and mean age at renal transplantation was 10.4 +/- 4.1 yr. Mutational analysis of NPHS2 was performed using polymerase chain reaction and direct sequencing. We found a synonymous T/C polymorphism at alanine 318 (GCC to GCT) in seven of 11 patients but no other causative NPHS2 mutations. FSGS recurred immediately after transplant in seven patients, while the remaining four patients had no recurrence for 3.2-5.8 yr. There were no differences between recurrent and non-recurrent patients in the onset age and the interval from onset to ESRD. In conclusion, we detected no causative NPHS2 mutations in Japanese pediatric FSGS patients with or without post-transplant recurrence. Further studies on the involvement of other genes are required to better understand recurrent FSGS.
Collapse
Affiliation(s)
- Takeki Furue
- Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Löwik M, Levtchenko E, Westra D, Groenen P, Steenbergen E, Weening J, Lilien M, Monnens L, van den Heuvel L. Bigenic heterozygosity and the development of steroid-resistant focal segmental glomerulosclerosis. Nephrol Dial Transplant 2008; 23:3146-51. [PMID: 18443213 DOI: 10.1093/ndt/gfn208] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Focal segmental glomerulosclerosis (FSGS) is a major cause of steroid-resistant nephrotic syndrome in childhood with a central role for the podocytes in the pathogenesis. Mutated proteins expressed in podocytes cause proteinuria. The role of combined gene defects in the development of FSGS is less clear. METHODS We analysed seven podocyte genes known to cause proteinuria and FSGS in a group of 19 non-familial childhood-onset steroid-resistant FSGS patients. These genes include NPHS1, NPHS2, ACTN4, CD2AP, WT-1, TRPC6 and PLCE1. We also screened for the mitochondrial A3243G DNA transition associated with the MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), and occasionally FSGS. RESULTS No mutations were found in the ACTN4 and TRPC6 genes, and no mitochondrial A3243G DNA transition was found in our group of patients. Two patients showed mutations in the CD2AP gene, one combined with an NPHS2 mutation. A tri-allelic hit was found in a patient carrying compound heterozygous NPHS2 mutations and a heterozygous NPHS1 mutation. In another patient a de novo WT-1 mutation was found combined with a heterozygous NPHS1 mutation, and finally two patients showed three heterozygous PLCE1 mutations. CONCLUSIONS In our rather small group of 19 steroid-resistant FSGS patients, we found 11 mutations in podocyte genes in 6 patients. In four of them the found mutations could explain the pathology. Our data suggest that combined gene defects in podocyte genes may play a role in the development of FSGS.
Collapse
Affiliation(s)
- Marije Löwik
- Department of Paediatric Nephrology, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Bakr A, Yehia S, El-Ghannam D, Hammad A, Ragab M, Sarhan A, Al-Husseni F, Al-Morsy Z. NPHS2 mutations. Indian J Pediatr 2008; 75:135-8. [PMID: 18334793 DOI: 10.1007/s12098-008-0020-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To uncover the frequency and the spectrum of NPHS2 mutations in Egyptian children with non familial steroid-resistant nephrotic syndrome (SRNS). METHODS Sixteen patients were screened by PCR-single-strand conformation polymorphism analysis of NPHS2 gene followed by direct sequencing. RESULTS NPHS2 mutations were evident in four patients (25%) who were bearing four novel mutations including two frame shift mutations (R238fs and P45fs) and two missense mutations (I136L and F216Y). There were no phenotypic or histological characteristics of patients bearing NPHS2 mutations, apart from the earlier onset of the disease, compared to those who were not bearing mutations. CONCLUSION NPHS2 mutations are prevalent in Egyptian children with non-familial SRNS and this may in part explain the less favorable prognosis reported in these patients.
Collapse
Affiliation(s)
- Ashraf Bakr
- Department of Pediatric Nephrology, Mansoura University Children's Hospital, Mansoura, Egypt.
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Berdeli A, Mir S, Yavascan O, Serdaroglu E, Bak M, Aksu N, Oner A, Anarat A, Donmez O, Yildiz N, Sever L, Tabel Y, Dusunsel R, Sonmez F, Cakar N. NPHS2 (podicin) mutations in Turkish children with idiopathic nephrotic syndrome. Pediatr Nephrol 2007; 22:2031-40. [PMID: 17899208 DOI: 10.1007/s00467-007-0595-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 07/10/2007] [Accepted: 07/13/2007] [Indexed: 10/22/2022]
Abstract
The podocin (NPHS2) gene encodes podocin protein, which has an important role in glomerular ultrafiltration and controlling slit membrane permeability. The detection of an NPHS2 mutation affects the treatment plan for children with nephritic syndrome (NS). The frequency and spectrum of podocin mutations in the Turkish population have remained largely unknown. The aim of this study was to screen for podocin mutations in Turkish patients with steroid-resistant NS (SRNS) and to compare it with other published series. There were 295 children with SRNS, originating from Turkey, included in this study. Forty-one patients (13.8%) had familial NS and 254 patients (86.2%) had sporadic NS. Mutation analysis was performed in all eight exons of the NPHS2 gene with the direct DNA sequencing method. There were 53 different pathogenetic NPHS2 mutations detected, including 37 novel mutations. The mutation detection rate was 24.7% for all patients, 29.2% for familial, and 24% for sporadic SRNS. The most common mutated exon was exon 5 (52 allele). The presence of mutations in exon 4 was found to increase the risk of end-stage renal disease (ESRD). Among patients with mutations, the rates of renal failure and/or ESRD (26%) were significantly higher than in those without mutations (12.6%). The mean time of progression to renal failure and ESRD in patients with mutations (1.8 +/- 2.5 years) was significantly shorter than in patients without mutations (3.7 +/- 4.0 years). Additionally, in patients with heterozygote mutations, fewer cases (13.6%) progressed to renal failure and/or ESRD than in with patients who had homozygote/compound heterozygote mutations (31.3%). In conclusion, podocin mutations are responsible for some of both familial and sporadic SRNS cases in Turkey. The mutations in this gene should be searched for in every child after presentation with the first episode of NS.
Collapse
Affiliation(s)
- Afig Berdeli
- Department of Molecular Genetics, Ege University Faculty of Medicine, Izmir, Turkey.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Meyer TN, Thaiss F, Stahl RAK. Immunoadsorbtion and rituximab therapy in a second living-related kidney transplant patient with recurrent focal segmental glomerulosclerosis. Transpl Int 2007; 20:1066-71. [PMID: 17887957 DOI: 10.1111/j.1432-2277.2007.00562.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A 29-year-old patient with focal segmental glomerulosclerosis (FSGS) and recurrence of the disease in a living donor kidney transplant received a second living-related kidney graft. She received pre- and postoperative immunoadsorptions and immunosuppression with tacrolimus, mycophenolate mofetil, basiliximab and steroids. Serum creatinine returned to normal values and only minor proteinuria was detected post-transplant (400 mg/24 h). However, recurrence of proteinuria with up to 3.3 g/24 h occurred 2 months after transplantation and the patient underwent intermediate immunoadsorption sessions with immediate reduction of proteinuria for the following year. She then received three doses of rituximab (600 mg, 375 mg/m(2)) that caused immediate reduction of proteinuria with only minimal increase in the following 12 months. Graft function is excellent 2 years after transplantation. These findings suggest that intermittent immunoadsorption combined with B-cell depletion by rituximab treatment induced prolonged reduction of proteinuria in a high-risk patient for recurrence of FSGS in the graft.
Collapse
Affiliation(s)
- Tobias N Meyer
- Department of Internal Medicine, University Hospital Hamburg, Hamburg, Germany.
| | | | | |
Collapse
|
50
|
Fine RN. Recurrence of nephrotic syndrome/focal segmental glomerulosclerosis following renal transplantation in children. Pediatr Nephrol 2007; 22:496-502. [PMID: 17186280 PMCID: PMC1805045 DOI: 10.1007/s00467-006-0361-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/24/2006] [Accepted: 08/28/2006] [Indexed: 12/24/2022]
Abstract
The incidence of recurrence of nephrotic syndrome/focal segmental glomerulosclerosis (NS/FSGS) is variable (~30%). The incidence of recurrence is less in African-Americans than in whites and Hispanics. Graft survival rates are decreased in recipients with FSGS, especially if remission of the NS is not achieved in those with recurrence. Although controversial, the use of living donor (LD) transplants are not contraindicated; however, obligatory heterozygote parental grafts with a podocin mutation should be used with caution. Optimal treatment to induce a remission post-transplant has not been delineated. Pre-transplant and/or prophylactic post-transplant pre-operative plasmapheresis (PP) for high-risk patients--especially those with recurrence in a previous graft--may be promising. An international multicenter controlled study is required to delineate the optimal approach to prevent and/or treat the recurrence of NS/FSGS.
Collapse
Affiliation(s)
- Richard N Fine
- School of Medicine, Stony Brook University, Stony Brook, NY 11794-8111, USA.
| |
Collapse
|