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Szafranski K, Kramer M. It's a bit over, is that ok? The subtle surplus from tandem alternative splicing. RNA Biol 2015; 12:115-22. [PMID: 25826565 DOI: 10.1080/15476286.2015.1017210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tandem alternative splice sites (TASS) form a defined class of alternative splicing and give rise to mRNA insertion/deletion variants with only small size differences. Previous work has confirmed evolutionary conservation of TASS elements while many cases show only low tissue specificity of isoform ratios. We pinpoint stochasticity and noise as important methodological issues for the dissection of TASS isoform patterns. Resolving such uncertainties, a recent report showed regulation in a cell culture system, with shifts of alternative splicing isoform ratios dependent on cell density. This novel type of regulation affects not only multiple TASS isoforms, but also other alternative splicing classes, in a concerted manner. Here, we discuss how specific regulatory network architectures may be realized through the novel regulation type and highlight the role of differential isoform functions as a key step in order to better understand the functional role of TASS.
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Affiliation(s)
- Karol Szafranski
- a Fritz Lipmann Institute - Leibniz Institute on Aging ; Jena , Germany
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Total Laparoscopic Colocolpopoiesis in a Kidney Transplant Recipient With Frasier Syndrome. Female Pelvic Med Reconstr Surg 2015; 22:e11-3. [PMID: 26516816 DOI: 10.1097/spv.0000000000000216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND The absence of a normal functioning vagina can have a profound impact on women's quality of life and psychological well being. Frasier syndrome is a rare autosomal recessive disorder which presents with male pseudohermaphroditism with gonadal dysgenesis, renal failure in early adulthood and increased risk of developing gonadoblastoma. Kidney transplant recipients are reported to have a high complication rate after colorectal surgery, most probably resulting from immunosuppressive therapy. CASE A 25-year-old female kidney transplant recipient with Frasier syndrome consulted our department to discuss the possibilities of surgically constructing a functional vagina. She successfully underwent a total laparoscopic colocolpopoiesis without any complications. A sigmoid segment of 16 cm long was isolated laparoscopically and transferred caudally in a dissected pouch between bladder and rectum on its vascular pedicle. There was no short-term morbidity and no complications up to 3 years postoperatively. She experienced no neovaginal symptoms and was able to engage in neovaginal penetration by means of vibrator or neovaginal dilatator. CONCLUSIONS The positive results in this patient lead us to recommend laparoscopic colocolpopoiesis in kidney transplant patients who are seeking vaginoplasty. We advocate considering a total laparoscopic approach whenever rectosigmoid colocolpopoiesis is indicated, even after a kidney transplantation.
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Lefebvre J, Clarkson M, Massa F, Bradford ST, Charlet A, Buske F, Lacas-Gervais S, Schulz H, Gimpel C, Hata Y, Schaefer F, Schedl A. Alternatively spliced isoforms of WT1 control podocyte-specific gene expression. Kidney Int 2015; 88:321-31. [DOI: 10.1038/ki.2015.140] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 03/26/2015] [Accepted: 03/26/2015] [Indexed: 01/26/2023]
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Chen YM, Liapis H. Focal segmental glomerulosclerosis: molecular genetics and targeted therapies. BMC Nephrol 2015; 16:101. [PMID: 26156092 PMCID: PMC4496884 DOI: 10.1186/s12882-015-0090-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 06/16/2015] [Indexed: 12/18/2022] Open
Abstract
Recent advances show that human focal segmental glomerulosclerosis (FSGS) is a primary podocytopathy caused by podocyte-specific gene mutations including NPHS1, NPHS2, WT-1, LAMB2, CD2AP, TRPC6, ACTN4 and INF2. This review focuses on genes discovered in the investigation of complex FSGS pathomechanisms that may have implications for the current FSGS classification scheme. It also recounts recent recommendations for clinical management of FSGS based on translational studies and clinical trials. The advent of next-generation sequencing promises to provide nephrologists with rapid and novel approaches for the diagnosis and treatment of FSGS. A stratified and targeted approach based on the underlying molecular defects is evolving.
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Affiliation(s)
- Ying Maggie Chen
- Renal Division, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO, 63110, USA.
| | - Helen Liapis
- , Nephropath, Little Rock, Arkansas
- Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
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Bandiera R, Sacco S, Vidal VPI, Chaboissier MC, Schedl A. Steroidogenic organ development and homeostasis: A WT1-centric view. Mol Cell Endocrinol 2015; 408:145-55. [PMID: 25596547 DOI: 10.1016/j.mce.2015.01.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/06/2015] [Accepted: 01/06/2015] [Indexed: 01/09/2023]
Abstract
Adrenal and gonads are the main steroidogenic organs and are central to regulate body homeostasis in the vertebrate organism. Although adrenals and gonads are physically separated in the adult organism, both organs share a common developmental origin, the adrenogonadal primordium. One of the key genes involved in the development of both organs is the Wilms' tumor suppressor WT1, which encodes a zinc finger protein that has fascinated the scientific community for more than two decades. This review will provide an overview of the processes leading to the development of these unique organs with a particular focus on the multiple functions WT1 serves during adrenogonadal development. In addition, we will highlight some recent findings and open questions on how maintenance of steroidogenic organs is achieved in the adult organism.
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Affiliation(s)
- Roberto Bandiera
- Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Sonia Sacco
- Institute of Biology Valrose, Université de Nice-Sophia, F-06108 Nice, France; Inserm, UMR1091, F-06108, France; CNRS, UMR7277, F-06108, France
| | - Valerie P I Vidal
- Institute of Biology Valrose, Université de Nice-Sophia, F-06108 Nice, France; Inserm, UMR1091, F-06108, France; CNRS, UMR7277, F-06108, France
| | - Marie-Christine Chaboissier
- Institute of Biology Valrose, Université de Nice-Sophia, F-06108 Nice, France; Inserm, UMR1091, F-06108, France; CNRS, UMR7277, F-06108, France
| | - Andreas Schedl
- Institute of Biology Valrose, Université de Nice-Sophia, F-06108 Nice, France; Inserm, UMR1091, F-06108, France; CNRS, UMR7277, F-06108, France.
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56
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Lehnhardt A, Karnatz C, Ahlenstiel-Grunow T, Benz K, Benz MR, Budde K, Büscher AK, Fehr T, Feldkötter M, Graf N, Höcker B, Jungraithmayr T, Klaus G, Koehler B, Konrad M, Kranz B, Montoya CR, Müller D, Neuhaus TJ, Oh J, Pape L, Pohl M, Royer-Pokora B, Querfeld U, Schneppenheim R, Staude H, Spartà G, Timmermann K, Wilkening F, Wygoda S, Bergmann C, Kemper MJ. Clinical and molecular characterization of patients with heterozygous mutations in wilms tumor suppressor gene 1. Clin J Am Soc Nephrol 2015; 10:825-31. [PMID: 25818337 DOI: 10.2215/cjn.10141014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 01/20/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVES The Wilms tumor suppressor gene 1 (WT1) plays an essential role in urogenital and kidney development. Genotype/phenotype correlations of WT1 mutations with renal function and proteinuria have been observed in world-wide cohorts with nephrotic syndrome or Wilms tumor (WT). This study analyzed mid-European patients with known constitutional heterozygous mutations in WT1, including patients without proteinuria or WT. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS Retrospective analysis of genotype, phenotype, and treatment of 53 patients with WT1 mutation from all pediatric nephrology centers in Germany, Austria, and Switzerland performed from 2010 to 2012. RESULTS Median age was 12.4 (interquartile range [IQR], 6-19) years. Forty-four of 53 (83%) patients had an exon mutation (36 missense, eight truncating), and nine of 53 (17%) had an intronic lysine-threonine-serine (KTS) splice site mutation. Fifty of 53 patients (94%) had proteinuria, which occurred at an earlier age in patients with missense mutations (0.6 [IQR, 0.1-1.5] years) than in those with truncating (9.7 [IQR, 5.7-11.9]; P<0.001) and splice site (4.0 [IQR, 2.6-6.6]; P=0.004) mutations. Thirteen of 50 (26%) were treated with steroids and remained irresponsive, while three of five partially responded to cyclosporine A. Seventy-three percent of all patients required RRT, those with missense mutations significantly earlier (at 1.1 [IQR, 0.01-9.3] years) than those with truncating mutations (16.5 [IQR, 16.5-16.8]; P<0.001) and splice site mutations (12.3 [IQR, 7.9-18.2]; P=0.002). Diffuse mesangial sclerosis was restricted to patients with missense mutations, while focal segmental sclerosis occurred in all groups. WT occurred only in patients with exon mutations (n=19). Fifty of 53 (94%) patients were karyotyped: Thirty-one (62%) had XY and 19 (38%) had XX chromosomes, and 96% of male karyotypes had urogenital malformations. CONCLUSIONS Type and location of WT1 mutations have predictive value for the development of proteinuria, renal insufficiency, and WT. XY karyotype was more frequent and associated with urogenital malformations in most cases.
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Affiliation(s)
- Anja Lehnhardt
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material.
| | - Claartje Karnatz
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Thurid Ahlenstiel-Grunow
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Kerstin Benz
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Marcus R Benz
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Klemens Budde
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Anja K Büscher
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Thomas Fehr
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Markus Feldkötter
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Norbert Graf
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Britta Höcker
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Therese Jungraithmayr
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Günter Klaus
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Birgit Koehler
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Martin Konrad
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Birgitta Kranz
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Carmen R Montoya
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Dominik Müller
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Thomas J Neuhaus
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Jun Oh
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Lars Pape
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Martin Pohl
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Brigitte Royer-Pokora
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Uwe Querfeld
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Reinhard Schneppenheim
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Hagen Staude
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Giuseppina Spartà
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Kirsten Timmermann
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Frauke Wilkening
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Simone Wygoda
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Carsten Bergmann
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
| | - Markus J Kemper
- Due to the number of contributing authors,the affiliations are provided in the Supplemental Material
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Rhen T, Fagerlie R, Schroeder A, Crossley DA, Lang JW. Molecular and morphological differentiation of testes and ovaries in relation to the thermosensitive period of gonad development in the snapping turtle, Chelydra serpentina. Differentiation 2015; 89:31-41. [PMID: 25662229 DOI: 10.1016/j.diff.2014.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/23/2014] [Accepted: 12/30/2014] [Indexed: 02/06/2023]
Abstract
Ambient temperatures during embryonic development determine gonadal sex in many reptiles. The temperature sensitive period for sex determination has been defined by shifting eggs between female- and male-producing temperatures in a few species. This phase spans 20-35% of embryogenesis in most species, which makes it difficult to define the mechanisms that transduce temperature into a signal for ovarian versus testicular development. We present an extensive set of studies that define a brief period when high temperature specifies, and then determines, ovarian fate in a northern population of snapping turtles, Chelydra serpentina. We shifted embryos from male to female temperatures, or vice versa, at various stages of development. Gonads in embryos incubated at female temperatures commit to ovarian fate earlier (by stage 18) than gonads in embryos incubated at male temperatures commit to testicular fate (by stages 19-21). In double shift studies, embryos were incubated at a female temperature, exposed to a male temperature for set times, and shifted back to the original temperature, or vice versa. The time required to induce ovarian development (≤6 days at female temperatures) was much shorter than the time required to induce testicular formation (>20 days at male temperatures). Differentiation of the gonads at the histological level occurred after the sex-determining period. Nevertheless, we found that a change in temperature rapidly (within 24h) influenced expression and splicing of WT1 mRNA: the absolute abundance of WT1 mRNA, the relative abundance of +KTS versus -KTS isoforms, as well as the ratio of +KTS:-KTS isoforms was higher in gonads at a male versus a female temperature. In conclusion, ovarian fate is more readily determined than testicular fate in snapping turtle embryos. The short sex-determining period in this species (6-8% of embryogenesis) will facilitate studies of molecular mechanisms for specification and determination of gonad fate by temperature.
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Affiliation(s)
- Turk Rhen
- Department of Biology, University of North Dakota, Grand Forks, ND 58202, USA.
| | - Ruby Fagerlie
- Department of Biology, University of North Dakota, Grand Forks, ND 58202, USA
| | - Anthony Schroeder
- Department of Biology, University of North Dakota, Grand Forks, ND 58202, USA
| | - Dane A Crossley
- Department of Biological Sciences, University of North Texas, Denton, TX 76210, USA
| | - Jeffrey W Lang
- Department of Biology, University of North Dakota, Grand Forks, ND 58202, USA
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Bagchi D, Andrade J, Shupnik MA. A new role for wilms tumor protein 1: differential activities of + KTS and -KTS variants to regulate LHβ transcription. PLoS One 2015; 10:e0116825. [PMID: 25617744 PMCID: PMC4305298 DOI: 10.1371/journal.pone.0116825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/15/2014] [Indexed: 01/08/2023] Open
Abstract
Luteinizing hormone (LH) is synthesized and secreted throughout the reproductive cycle from gonadotrope cells in the anterior pituitary, and is required for steroidogenesis and ovulation. LH contains an α-subunit common with FSH, and a unique LHβ subunit that defines biological activity. Basal LHβ transcription is low and stimulated by hypothalamic GnRH, which induces synthesis of early growth response protein-1 (Egr1), and stimulates binding of transcription factors Egr1 and steroidogenic factor-1 (SF1) on the promoter. WT1 (Wilms tumor protein1) is a zinc finger transcription factor with an essential role in urogenital system development, and which regulates several reproductive genes via interactions with SF1 or binding to GC-rich elements such as Egr1 binding sites. We investigated a potential role for WT1 in LHβ transcription in clonal mouse gonadotrope LβT2 cells. WT1 was present in LβT2 and mouse pituitary cells, and protein bound to the endogenous LHβ promoter. Interestingly, mRNAs for WT1(+KTS), which contains a three amino-acid insertion between the 3rd and 4th zinc fingers, and the WT1 (-KTS) variant were both expressed at significant levels. WT1 mRNAs and protein were decreased approximately 50% by GnRH treatment, under conditions where Egr1 mRNA and protein, and LHβ transcription, were stimulated. Decreasing expression of mRNA for WT1 (-KTS) decreased stimulation of LHβ and Egr1 by GnRH, whereas decreasing both WT1 (-KTS) and (+KTS) increased endogenous LHβ transcription, and prevented LHβ but not Egr1 stimulation by GnRH, suggesting differing biological activities for the WT1 isoforms. Overexpression of WT1 showed that WT1(-KTS) enhanced LHβ promoter GnRH stimulation 2-to-3-fold and required the 3'Egr1 site, but WT1(+KTS) repressed both basal and GnRH-stimulated LHβ promoter activity by approximately 70%. Our data suggest that WT1 can modulate LHβ transcription, with differential roles for the two WT1 variants; WT1 (-KTS) enhances and WT1 (+KTS) suppresses transcription.
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Affiliation(s)
- Debalina Bagchi
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Josefa Andrade
- Department of Medicine, Division of Endocrinology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Margaret A. Shupnik
- Department of Medicine, Division of Endocrinology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
- * E-mail:
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Bińczak-Kuleta A, Rubik J, Litwin M, Ryder M, Lewandowska K, Taryma-Leśniak O, Clark JS, Grenda R, Ciechanowicz A. Retrospective mutational analysis of NPHS1, NPHS2, WT1 and LAMB2 in children with steroid-resistant focal segmental glomerulosclerosis - a single-centre experience. Bosn J Basic Med Sci 2015; 14:89-93. [PMID: 24856380 DOI: 10.17305/bjbms.2014.2270] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The aim of our study was to examine NPHS1, NPHS2, WT1 and LAMB2 mutations, previously reported in two thirds of patients with nephrotic syndrome with onset before the age of one year old. Genomic DNA samples from Polish children (n=33) with Steroid-Resistant Nephrotic Syndrome (SRNS) due to focal segmental glomerulosclerosis (FSGS), manifesting before the age of 13 years old, underwent retrospective analysis of NPHS1, NPHS2, WT1 (exons 8, 9 and adjacent exon/intron boundaries) and LAMB2. No pathogenic NPHS1 or LAMB2 mutations were found in our FSGS cohort. SRNS-causing mutations of NPHS2 and WT1 were detected in 7 of 33 patients (21%), including those with nephrotic syndrome manifesting before one year old: five of seven patients. Four patients had homozygous c.413G>A (p.Arg138Gln) NPHS2 mutations; one subject was homozygous for c.868G>A (p.Val290Met) NPHS2. A phenotypic female had C>T transition at position +4 of the WT1 intron 9 (c.1432+4C>T) splice-donor site, and another phenotypic female was heterozygous for G>A transition at position +5 (c.1432+5G>A). Genotyping revealed a female genotypic gender (46, XX) for the first subject and male (46, XY) for the latter. In addition, one patient was heterozygous for c.104dup (p.Arg36Profs*34) NPHS2; two patients carried a c.686G>A (p.Arg229Gln) NPHS2 non-neutral variant. Results indicate possible clustering of causative NPHS2 mutations in FSGS-proven SRNS with onset before age one year old, and provide additional evidence that patients with childhood steroid-resistant nephrotic syndrome due to focal segmental glomerulosclerosis should first undergo analysis of NPHS2 coding sequence and WT1 exons 8 and 9 and surrounding exon/intron boundary sequences, followed by gender genotyping.
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Affiliation(s)
- Agnieszka Bińczak-Kuleta
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Jacek Rubik
- Department of Nephrology, Kidney Transplantation and Hypertension, Children`s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Mieczysław Litwin
- Department of Nephrology, Kidney Transplantation and Hypertension, Children`s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Małgorzata Ryder
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Klaudyna Lewandowska
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Olga Taryma-Leśniak
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Jeremy S Clark
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
| | - Ryszard Grenda
- Department of Nephrology, Kidney Transplantation and Hypertension, Children`s Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland
| | - Andrzej Ciechanowicz
- Department of Clinical and Molecular Biochemistry, Pomeranian Medical University, al. Powstańców Wlkp. 72, 70-111 Szczecin, Poland
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Glomerular development--shaping the multi-cellular filtration unit. Semin Cell Dev Biol 2014; 36:39-49. [PMID: 25153928 DOI: 10.1016/j.semcdb.2014.07.016] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 01/09/2023]
Abstract
The glomerulus represents a highly structured filtration unit, composed of glomerular endothelial cells, mesangial cells, podocytes and parietal epithelial cells. During glomerulogenesis an intricate network of signaling pathways involving transcription factors, secreted factors and cell-cell communication is required to guarantee accurate evolvement of a functional, complex 3-dimensional glomerular architecture. Here, we want to provide an overview on the critical steps and relevant signaling cascades of glomerular development.
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ZITZMANN FERDINAND, MAYR DORIS, BERGER MICHAEL, STEHR MAXIMILIAN, VON SCHWEINITZ DIETRICH, KAPPLER ROLAND, HUBERTUS JOCHEN. Frequent hypermethylation of a CTCF binding site influences Wilms tumor 1 expression in Wilms tumors. Oncol Rep 2014; 31:1871-6. [DOI: 10.3892/or.2014.3019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 01/03/2014] [Indexed: 11/05/2022] Open
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62
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Lu MY, Wang WC, Lin CW, Chang A, Lai YC. Identification of a constitutional mutation in the WT1 gene in Taiwanese patients with Wilms tumor. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/abb.2014.53029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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63
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Abstract
Alternative pre-mRNA splicing is an integral part of gene regulation in eukaryotes. Here we provide a basic overview of the various types of alternative splicing, as well as the functional role, highlighting how alternative splicing varies across phylogeny. Regulated alternative splicing can affect protein function and ultimately impact biological outcomes. We examine the possibility that portions of alternatively spliced transcripts are the result of stochastic processes rather than regulated. We discuss the implications of misregulated alternative splicing and explore of the role of alternative splicing in human disease.
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Affiliation(s)
- Stacey D Wagner
- Department of Chemistry and Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
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Guaragna MS, Lutaif ACGDB, Bittencourt VB, Piveta CSC, Soardi FC, Castro LCG, Belangero VMS, Maciel-Guerra AT, Guerra-Junior G, Mello MPD. Frasier syndrome: four new cases with unusual presentations. ACTA ACUST UNITED AC 2013; 56:525-32. [PMID: 23295293 DOI: 10.1590/s0004-27302012000800011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 09/20/2012] [Indexed: 11/22/2022]
Abstract
Frasier syndrome (FS) is characterized by gonadal dysgenesis and nephropathy. It is caused by specific mutations in the Wilms' tumor suppressor gene (WT1) located in 11p23. Patients with the 46,XY karyotype present normal female genitalia with streak gonads, and have higher risk of gonadal tumor, mainly, gonadoblastoma. Therefore, elective bilateral gonadectomy is indicated. Nephropathy in FS consists in nephrotic syndrome (NS) with proteinuria that begins early in childhood and progressively increases with age, mainly due to nonspecific focal and segmental glomerular sclerosis (FSGS). Patients are generally unresponsive to steroid and immunosuppressive therapies, and will develop end-stage renal failure (ESRF) during the second or third decade of life. We report here four cases of FS diagnosis after identification of WT1 mutations. Case 1 was part of a large cohort of patients diagnosed with steroid-resistant nephrotic syndrome, in whom the screening for mutations within WT1 8-9 hotspot fragment identified the IVS9+5G>A mutation. Beside FS, this patient showed unusual characteristics, such as urinary malformation (horseshoe kidney), and bilateral dysgerminoma. Cases 2 and 3, also bearing the IVS9+5G>A mutation, and case 4, with IVS9+1G>A mutation, were studied due to FSGS and/or delayed puberty; additionally, patients 2 and 4 developed bilateral gonadal tumors. Since the great majority of FS patients have normal female external genitalia, sex reversal is not suspected before they present delayed puberty and/or primary amenorrhea. Therefore, molecular screening of WT1 gene is very important to confirm the FS diagnosis.
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Affiliation(s)
- Mara Sanches Guaragna
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP, Brazil
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Guaragna MS, Lutaif ACGB, Piveta CSC, Belangero VMS, Maciel-Guerra AT, Guerra G, De Mello MP. Two distinct WT1 mutations identified in patients and relatives with isolated nephrotic proteinuria. Biochem Biophys Res Commun 2013; 441:371-6. [PMID: 24161391 DOI: 10.1016/j.bbrc.2013.10.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 10/12/2013] [Indexed: 11/25/2022]
Abstract
Wilms' tumor type 1 gene (WT1) encodes a zinc-finger transcription factor that plays a key role during genitourinary development and in adult kidney. Mutations in exons 8 and 9 are associated with Denys-Drash Syndrome, whereas those occurring in the intron 9 donor splice site are associated with Frasier Syndrome. Familial cases of WT1 mutations are rare with only few cases described in the literature, whereas cases of WT1 mutations associated with isolated nephrotic proteinuria with or without focal segmental glomerular sclerosis (FSGS) are even rarer. Exons 8 and 9 of WT1 gene were analyzed in two non-related female patients and their parents. Patient 1, who presented with isolated nephrotic proteinuria and histologic pattern of FSGS, is heterozygous for the mutation c.1227+4C>T. This mutation was inherited from her mother, who had undergone kidney transplant due to FSGS. Patient 2 is heterozygous for the novel c.1178C>T transition inherited from her father. The putative effect of this nucleotide substitution on WT1 protein is p.Ser393Phe mutation located within the third zinc-finger domain. The patient and her father presented, respectively, isolated nephrotic proteinuria and chronic renal failure. These data highlight the importance of the inclusion of WT1 gene mutational analysis in patients with isolated nephrotic proteinuria, especially when similar conditions are referred to the family.
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Affiliation(s)
- Mara S Guaragna
- Centro de Biologia Molecular e Engenharia Genética - CBMEG, Universidade Estadual de Campinas, Unicamp, Campinas, SP, Brazil
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Zhu C, Zhao F, Zhang W, Wu H, Chen Y, Ding G, Zhang A, Huang S. A familial WT1 mutation associated with incomplete Denys-Drash syndrome. Eur J Pediatr 2013; 172:1357-62. [PMID: 23715653 DOI: 10.1007/s00431-013-2004-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 11/28/2022]
Abstract
UNLABELLED Denys-Drash syndrome (DDS) is a rare disorder characterized by nephropathy, male pseudohermaphroditism, and wilms tumor. Cases are thought to arise sporadically through a de novo mutation in the wilms tumor suppressor gene (WT1), which encodes a zinc finger protein that not only acts as a tumor suppressor but is essential for normal gonadogenesis, nephrogenesis, and development of the urogenital tract. In this report, we describe a family with the well-known missense mutation in exon 9 of the WT1 gene, 1180C>T (R394W), causing incomplete DDS and no symptoms in their father. The proband, a boy with 46, XY karyotype, was born with ambiguous genitalia, penoscrotal hypospadias, and bilateral inguinal hernias. At 2 years of age, he has proteinuria and diffuse mesangial sclerosis, but no wilms tumor has been detected. The elder sister of the proband, at 3 years of age, has normal genitalia, proteinuria, focal mesangial sclerosis but no wilms tumor. The WT1 mutation was detected in both patients, who have suspected DDS, and their father, who is phenotypically normal. CONCLUSION This case is unusual in that the 1180C>T mutation, which has been found in approximately 50 % of patients with complete DDS, has been inherited and is causing mild or no symptoms of DDS.
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Affiliation(s)
- Chunhua Zhu
- Department of Nephrology, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, 210008, Jiangsu Province, China
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Abstract
Renal biopsy was introduced in the 1950s. By 1980 the pathologic diagnostic criteria for the majority of medical kidney diseases known today, including pediatric diseases, were established using light, electron microscopy and immunohistochemistry. However, it has become clear that there are limitations in the morphologic evaluation, mainly because a given pattern of injury can be caused by different aetiologies and, conversely, a single aetiology may present with more than one histological pattern. An explosion in kidney disease research in the last 20-30 years has brought new knowledge from bench to bedside rapidly and resulted in new molecular and genetic tools that enhance the diagnostic and prognostic power of the renal biopsy. Genomic technologies such as polymerase chain reaction (PCR), in situ hybridization and oligonucleotide microarrays, collectively known as genomics, detect single or multiple genes underscoring the pathologic changes and revealing specific causes of injury that may require different treatment. The aims of this review are to (1) summarize current recommendations for diagnostic renal biopsies encompassing light microscopy, immunofluorescence or immunohistochemistry and electron microscopy; (2) address the limitations of morphology; (3) show current contributions of genomic technologies adjunct to the renal biopsy, and provide examples of how these may transform pathologic interpretation into molecular disease phenotypes.
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Esposito T, Lea RA, Maher BH, Moses D, Cox HC, Magliocca S, Angius A, Nyholt DR, Titus T, Kay T, Gray NA, Rastaldi MP, Parnham A, Gianfrancesco F, Griffiths LR. Unique X-linked familial FSGS with co-segregating heart block disorder is associated with a mutation in the NXF5 gene. Hum Mol Genet 2013; 22:3654-66. [PMID: 23686279 DOI: 10.1093/hmg/ddt215] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is the consequence of a disease process that attacks the kidney's filtering system, causing serious scarring. More than half of FSGS patients develop chronic kidney failure within 10 years, ultimately requiring dialysis or renal transplantation. There are currently several genes known to cause the hereditary forms of FSGS (ACTN4, TRPC6, CD2AP, INF2, MYO1E and NPHS2). This study involves a large, unique, multigenerational Australian pedigree in which FSGS co-segregates with progressive heart block with apparent X-linked recessive inheritance. Through a classical combined approach of linkage and haplotype analysis, we identified a 21.19 cM interval implicated on the X chromosome. We then used a whole exome sequencing approach to identify two mutated genes, NXF5 and ALG13, which are located within this linkage interval. The two mutations NXF5-R113W and ALG13-T141L segregated perfectly with the disease phenotype in the pedigree and were not found in a large healthy control cohort. Analysis using bioinformatics tools predicted the R113W mutation in the NXF5 gene to be deleterious and cellular studies support a role in the stability and localization of the protein suggesting a causative role of this mutation in these co-morbid disorders. Further studies are now required to determine the functional consequence of these novel mutations to development of FSGS and heart block in this pedigree and to determine whether these mutations have implications for more common forms of these diseases in the general population.
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Affiliation(s)
- Teresa Esposito
- Institute of Genetics and Biophysics Adriano Buzzati-Traverso, National Research Council of Italy, Naples, Italy
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El-Sherbiny M. Disorders of sexual differentiation: I. Genetics and pathology. Arab J Urol 2013; 11:19-26. [PMID: 26579240 PMCID: PMC4442963 DOI: 10.1016/j.aju.2012.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 11/03/2012] [Accepted: 11/08/2012] [Indexed: 11/17/2022] Open
Abstract
Objectives To provide a summary of the recent major advances in the field of molecular genetics and understanding of psychosexual development, as these developments have resulted in changes in terminology and classification of disorders of sexual differentiation (DSD)/intersex; and to provide a quick and simplified review of the basic information. Methods Recent publications (over the last 10 years) were identified by a PubMed search, as were relevant previous studies, using the keywords; ‘sex chromosomes’, ‘psychosexual development’, ‘classifications’, ‘disorders of sexual differentiation’, ‘Chicago consensus’, ‘gonadal malignancy’, ‘intersex’ and ‘ambiguous genitalia’. Results The newly proposed terminology and classification has eliminated some confusion for both patient and family, as well as among health professionals. The new advances have facilitated the categorisation of gonadal malignancy in patients with DSD into high-, intermediate- and low-risk groups. Conclusions The major changes in terminology and classification of DSD should be considered as the first steps on a long road of research effort. The current available data remain far from sufficient. More molecular genetics studies will allow a better understanding of the causes of each condition of DSD.
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Key Words
- CAH, congenital adrenal hyperplasia
- CAIS, complete androgen insensitivity syndrome
- CIS, carcinoma in situ
- Chicago Consensus
- Classification
- DSD, disorder(s) of sexual differentiation
- Gonadal malignancy
- Intersex
- MGD, mixed gonadal dysgenesis
- MIS, Müllerian-inhibiting substance
- PMDS, persistent Müllerian duct syndrome
- Psychosexual development
- SF-1, steroidogenic factor 1
- SRY, sex-determining region on the Y chromosome
- Sex chromosomes
- WT-1, Wilms’ tumour-1 gene
- hCG, human chorionic gonadotrophin
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Affiliation(s)
- Mohamed El-Sherbiny
- Address: Paediatric Surgery (Urology), Montreal Children’s Hospital, C527-2300 Rue Tupper, Montreal, Quebec, Canada H3H1P3. Tel.: +1 514 4124366.
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Menendez-Castro C, Hilgers KF, Amann K, Daniel C, Cordasic N, Wachtveitl R, Fahlbusch F, Plank C, Dötsch J, Rascher W, Hartner A. Intrauterine growth restriction leads to a dysregulation of Wilms' tumour supressor gene 1 (WT1) and to early podocyte alterations. Nephrol Dial Transplant 2012; 28:1407-17. [PMID: 23229934 DOI: 10.1093/ndt/gfs517] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Intrauterine growth restriction (IUGR) leads to low nephron number and higher incidence of renal disease. We hypothesized that IUGR induces early podocyte alterations based on a dysregulation of Wilms' tumour suppressor gene 1 (WT1), a key player of nephrogenesis and mediator of podocyte integrity. METHODS IUGR was induced in rats by maternal protein restriction during pregnancy. Kidneys were harvested from male offspring at Days 1 and 70 of life. qRT-PCR, immunohistochemistry and electron microscopy were performed in renal tissue. Albuminuria was assessed by enzyme-linked immunosorbent assay. RESULTS At Day 70 of life, higher albuminuria and overt alterations of podocyte ultrastructure were detected in IUGR animals in spite of normal blood pressure. Moreover, we found increased glomerular immunoreactivity and expression of desmin, while synaptopodin and nephrin were decreased. Glomerular immunoreactivity and expression of WT1 were increased in IUGR animals at this time point with an altered expressional ratio of WT1 +KTS and -KTS isoforms. These changes of WT1 expression were already present at the time of birth. CONCLUSIONS IUGR results in early podocyte damage possibly due to a dysregulation of WT1. We suggest that an imbalance of WT1 isoforms to the disadvantage of -KTS affects nephrogenesis in IUGR rats and that persistent dysregulation of WT1 results in a reduced ability to maintain podocyte integrity, rendering IUGR rats more susceptible for renal disease.
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Affiliation(s)
- Carlos Menendez-Castro
- Department of Pediatrics and Adolescent Medicine, University of Erlangen-Nuremberg, Erlangen, Germany.
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71
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PAX2 in human kidney malformations and disease. Pediatr Nephrol 2012; 27:1265-75. [PMID: 22138676 DOI: 10.1007/s00467-011-2053-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 10/10/2011] [Accepted: 10/18/2011] [Indexed: 10/14/2022]
Abstract
Human PAX2 mutations have been associated with abnormalities in the developing and adult kidney ranging from congenital abnormalities of the kidney and urinary tract (CAKUT) to oncogenic processes. Defining the relationship of PAX2 to human renal disease requires an appreciation of its fundamental role in renal development. Given the highly conserved nature of the PAX2 gene in vertebrates, it is not surprising that much of our understanding of PAX2 involvement in renal disease has been derived from animal models. The following review will outline the current evidence supporting involvement of PAX2 in the pathologic processes involving the kidney.
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72
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Hersmus R, van der Zwan YG, Stoop H, Bernard P, Sreenivasan R, Oosterhuis JW, Brüggenwirth HT, de Boer S, White S, Wolffenbuttel KP, Alders M, McElreavy K, Drop SLS, Harley VR, Looijenga LHJ. A 46,XY female DSD patient with bilateral gonadoblastoma, a novel SRY missense mutation combined with a WT1 KTS splice-site mutation. PLoS One 2012; 7:e40858. [PMID: 22815844 PMCID: PMC3399878 DOI: 10.1371/journal.pone.0040858] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 06/14/2012] [Indexed: 12/18/2022] Open
Abstract
Patients with Disorders of Sex Development (DSD), especially those with gonadal dysgenesis and hypovirilization are at risk of developing malignant type II germ cell tumors/cancer (GCC) (seminoma/dysgerminoma and nonseminoma), with either carcinoma in situ (CIS) or gonadoblastoma (GB) as precursor lesion. In 10–15% of 46,XY gonadal dysgenesis cases (i.e., Swyer syndrome), SRY mutations, residing in the HMG (High Mobility Group) domain, are found to affect nuclear transport or binding to and bending of DNA. Frasier syndrome (FS) is characterized by gonadal dysgenesis with a high risk for development of GB as well as chronic renal failure in early adulthood, and is known to arise from a splice site mutation in intron 9 of the Wilms’ tumor 1 gene (WT1). Mutations in SRY as well as WT1 can lead to diminished expression and function of SRY, resulting in sub-optimal SOX9 expression, Sertoli cell formation and subsequent lack of proper testicular development. Embryonic germ cells residing in this unfavourable micro-environment have an increased risk for malignant transformation. Here a unique case of a phenotypically normal female (age 22 years) is reported, presenting with primary amenorrhoea, later diagnosed as hypergonadotropic hypogonadism on the basis of 46,XY gonadal dygenesis with a novel missense mutation in SRY. Functional in vitro studies showed no convincing protein malfunctioning. Laparoscopic examination revealed streak ovaries and a normal, but small, uterus. Pathological examination demonstrated bilateral GB and dysgerminoma, confirmed by immunohistochemistry. Occurrence of a delayed progressive kidney failure (focal segmental glomerular sclerosis) triggered analysis of WT1, revealing a pathogenic splice–site mutation in intron 9. Analysis of the SRY gene in an additional five FS cases did not reveal any mutations. The case presented shows the importance of multi-gene based diagnosis of DSD patients, allowing early diagnosis and treatment, thus preventing putative development of an invasive cancer.
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Affiliation(s)
- Remko Hersmus
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
| | - Yvonne G. van der Zwan
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
- Department of Pediatric Endocrinology, Erasmus MC - University Medical Center Rotterdam, Sophia Children’s Hospital, Rotterdam, The Netherlands
| | - Hans Stoop
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
| | - Pascal Bernard
- Molecular Genetics and Development Division, Prince Henry’s Institute of Medical Research, Clayton, Victoria, Australia
| | - Rajini Sreenivasan
- Molecular Genetics and Development Division, Prince Henry’s Institute of Medical Research, Clayton, Victoria, Australia
- Department of Anatomy and Cell Biology, The University of Melbourne, Victoria, Australia
| | - J. Wolter Oosterhuis
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
| | - Hennie T. Brüggenwirth
- Department of Clinical Genetics, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Suzan de Boer
- Centre for Reproduction and Development, Monash Institute of Medical Research, Clayton, Victoria, Australia
| | - Stefan White
- Centre for Reproduction and Development, Monash Institute of Medical Research, Clayton, Victoria, Australia
| | - Katja P. Wolffenbuttel
- Department of Pediatric Urology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marielle Alders
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Stenvert L. S. Drop
- Department of Pediatric Endocrinology, Erasmus MC - University Medical Center Rotterdam, Sophia Children’s Hospital, Rotterdam, The Netherlands
| | - Vincent R. Harley
- Molecular Genetics and Development Division, Prince Henry’s Institute of Medical Research, Clayton, Victoria, Australia
| | - Leendert H. J. Looijenga
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
- * E-mail:
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Correa SM, Washburn LL, Kahlon RS, Musson MC, Bouma GJ, Eicher EM, Albrecht KH. Sex reversal in C57BL/6J XY mice caused by increased expression of ovarian genes and insufficient activation of the testis determining pathway. PLoS Genet 2012; 8:e1002569. [PMID: 22496664 PMCID: PMC3320579 DOI: 10.1371/journal.pgen.1002569] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Accepted: 01/16/2012] [Indexed: 11/18/2022] Open
Abstract
Sex reversal can occur in XY humans with only a single functional WT1 or SF1 allele or a duplication of the chromosome region containing WNT4. In contrast, XY mice with only a single functional Wt1, Sf1, or Wnt4 allele, or mice that over-express Wnt4 from a transgene, reportedly are not sex-reversed. Because genetic background plays a critical role in testis differentiation, particularly in C57BL/6J (B6) mice, we tested the hypothesis that Wt1, Sf1, and Wnt4 are dosage sensitive in B6 XY mice. We found that reduced Wt1 or Sf1 dosage in B6 XY(B6) mice impaired testis differentiation, but no ovarian tissue developed. If, however, a Y(AKR) chromosome replaced the Y(B6) chromosome, these otherwise genetically identical B6 XY mice developed ovarian tissue. In contrast, reduced Wnt4 dosage increased the amount of testicular tissue present in Sf1+/- B6 XY(AKR), Wt1+/- B6 XY(AKR), B6 XY(POS), and B6 XY(AKR) fetuses. We propose that Wt1(B6) and Sf1(B6) are hypomorphic alleles of testis-determining pathway genes and that Wnt4(B6) is a hypermorphic allele of an ovary-determining pathway gene. The latter hypothesis is supported by the finding that expression of Wnt4 and four other genes in the ovary-determining pathway are elevated in normal B6 XX E12.5 ovaries. We propose that B6 mice are sensitive to XY sex reversal, at least in part, because they carry Wt1(B6) and/or Sf1(B6) alleles that compromise testis differentiation and a Wnt4(B6) allele that promotes ovary differentiation and thereby antagonizes testis differentiation. Addition of a "weak" Sry allele, such as the one on the Y(POS) chromosome, to the sensitized B6 background results in inappropriate development of ovarian tissue. We conclude that Wt1, Sf1, and Wnt4 are dosage-sensitive in mice, this dosage-sensitivity is genetic background-dependant, and the mouse strains described here are good models for the investigation of human dosage-sensitive XY sex reversal.
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Affiliation(s)
- Stephanie M. Correa
- Department of Medicine, Biomedical Genetics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | | | - Ravi S. Kahlon
- Department of Medicine, Biomedical Genetics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Michelle C. Musson
- Department of Medicine, Biomedical Genetics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Gerrit J. Bouma
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Eva M. Eicher
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Kenneth H. Albrecht
- Department of Medicine, Biomedical Genetics, Boston University School of Medicine, Boston, Massachusetts, United States of America
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail:
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Rood IM, Deegens JKJ, Wetzels JFM. Genetic causes of focal segmental glomerulosclerosis: implications for clinical practice. Nephrol Dial Transplant 2012; 27:882-90. [PMID: 22334613 DOI: 10.1093/ndt/gfr771] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a common cause of steroid-resistant nephrotic syndrome in children and adults. Although FSGS is considered a podocyte disease, the aetiology is diverse. In recent years, many inheritable genetic forms of FSGS have been described, caused by mutations in proteins that are important for podocyte function. In the present commentary, we review these genetic causes of FSGS and describe their prevalence in familial and sporadic FSGS. In routine clinical practice, the decision to perform the costly DNA analysis should be based on the assessment if the results affect the care of the individual patient with respect to the evaluation of extra-renal manifestations, treatment decisions, transplantation and genetic counselling.
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Affiliation(s)
- Ilse M Rood
- Department of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Broad and unexpected phenotypic expression in Greek children with steroid-resistant nephrotic syndrome due to mutations in the Wilms' tumor 1 (WT1) gene. Eur J Pediatr 2011; 170:1529-34. [PMID: 21499692 DOI: 10.1007/s00431-011-1450-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 03/08/2011] [Indexed: 01/26/2023]
Abstract
Mutations in the Wilms' tumor suppressor gene 1 (WT1), most commonly within exons 8 or 9 or intron 9, are found in cases with the overlapping conditions of Denys-Drash and Frasier syndromes, as well as in patients with steroid-resistant nephrotic syndrome (SRNS). This study investigated the presence of WT1 gene mutations in cases with childhood SRNS, along with an evaluation of their clinical outcome. Twenty-seven Greek children with sporadic (19 cases) and familial (8 cases) SRNS were tested. Four phenotypically female patients with sporadic SRNS were found to carry de novo WT1 mutations, including two cases with p.R394W, and one case each with p.R366H, or n.1228+5G>A. Karyotype analysis found 46XX in three cases, but 46XY in one. No phenotype-genotype correlations were apparent in the WT1 gene positive cases since their clinical presentation varied broadly. Interestingly, one patient with a pathological WT1 nucleotide variation responded fully to combined therapy with cyclosporine A and corticosteroids. This study further illustrates that investigation of WT1 gene mutations is clinically useful to support definitive diagnosis in children presenting with SRNS in order to direct the most appropriate clinical management.
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Lockett GA, Kucharski R, Maleszka R. DNA methylation changes elicited by social stimuli in the brains of worker honey bees. GENES BRAIN AND BEHAVIOR 2011; 11:235-42. [PMID: 22098706 DOI: 10.1111/j.1601-183x.2011.00751.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Social environments are notoriously multifactorial, yet studies in rodents have suggested that single variables such as maternal care can in fact be disentangled and correlated with specific DNA methylation changes. This study assesses whether non-detrimental social environmental variation in a highly plastic social insect is correlated with epigenomic modifications at the DNA methylation level. Honey bee workers perform tasks such as nursing and foraging in response to the social environment in the hive, in an age-linked but not age-dependent manner. In this study, the methylation levels of 83 cytosine-phosphate-guanosine dinucleotides over eight genomic regions were compared between the brains of age-matched bees performing nursing or foraging tasks. The results reveal more changes correlated with task than with chronological age, and also hive-associated methylation at some sites. One methylation site from a gene encoding Protein Kinase C binding protein 1 was consistently more methylated in foragers than nurses, which is suggested to lead to production of task-specific protein isoforms via alternative splicing. This study illustrates the ability of the neural epigenome to dynamically respond to complex social stimuli.
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Affiliation(s)
- G A Lockett
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
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The podocyte as a target: cyclosporin A in the management of the nephrotic syndrome caused by WT1 mutations. Eur J Pediatr 2011; 170:1377-83. [PMID: 21298518 DOI: 10.1007/s00431-011-1397-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 01/11/2011] [Indexed: 01/03/2023]
Abstract
Children with steroid-resistant nephrotic syndrome secondary to WT1-associated glomerulopathies (WT1-GP) were considered unresponsive to cyclosporin A (CsA). This assumption is challenged by the findings of recent studies. The patients of these studies had different types of WT1 mutations and varying clinical presentations. However, all of them were of young age and the favourable response to CsA might be the result of treatment at an early stage of the disease. The additional administration of angiotensin-converting enzyme inhibitors may have contributed to the positive outcome. We review recent data on the role of WT1 in the development of WT1-GP and discuss putative therapeutic targets explaining the therapeutic effect of CsA.
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79
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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.
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Lange J, Peterson SM, Takashima JR, Grigoriev Y, Ritchey ML, Shamberger RC, Beckwith JB, Perlman E, Green DM, Breslow NE. Risk factors for end stage renal disease in non-WT1-syndromic Wilms tumor. J Urol 2011; 186:378-86. [PMID: 21683387 DOI: 10.1016/j.juro.2011.03.110] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Indexed: 01/25/2023]
Abstract
PURPOSE We assessed risk factors for end stage renal disease in patients with Wilms tumor without known WT1 related syndromes. We hypothesized that patients with characteristics suggestive of a WT1 etiology (early onset, stromal predominant histology, intralobar nephrogenic rests) would have a higher risk of end stage renal disease due to chronic renal failure. We predicted a high risk of end stage renal disease due to progressive bilateral Wilms tumor in patients with metachronous bilateral disease. MATERIALS AND METHODS End stage renal disease was ascertained in 100 of 7,950 nonsyndromic patients enrolled in a National Wilms Tumor Study during 1969 to 2002. Risk factors were evaluated with cumulative incidence curves and proportional hazard regressions. RESULTS The cumulative incidence of end stage renal disease due to chronic renal failure 20 years after Wilms tumor diagnosis was 0.7%. For end stage renal disease due to progressive bilateral Wilms tumor the incidence was 4.0% at 3 years after diagnosis in patients with synchronous bilateral Wilms tumor and 19.3% in those with metachronous bilateral Wilms tumor. For end stage renal disease due to chronic renal failure stromal predominant histology had a HR of 6.4 relative to mixed (95% CI 3.4, 11.9; p<0.001), intralobar rests had a HR of 5.9 relative to no rests (95% CI 2.0, 17.3; p=0.001), and Wilms tumor diagnosis at less than 24 months had a HR of 1.7 relative to 24 to 48 months and 2.8 relative to greater than 48 months (p=0.003 for trend). CONCLUSIONS Metachronous bilateral Wilms tumor is associated with high rates of end stage renal disease due to surgery for progressive Wilms tumor. Characteristics associated with a WT1 etiology markedly increased the risk of end stage renal disease due to chronic renal failure despite the low risk in non-WT1 syndromic cases overall.
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Affiliation(s)
- Jane Lange
- Department of Biostatistics, University of Washington, Seattle, Washington 98112, USA.
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81
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Leet JK, Gall HE, Sepúlveda MS. A review of studies on androgen and estrogen exposure in fish early life stages: effects on gene and hormonal control of sexual differentiation. J Appl Toxicol 2011; 31:379-98. [PMID: 21557264 DOI: 10.1002/jat.1682] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 02/23/2011] [Accepted: 02/24/2011] [Indexed: 11/09/2022]
Abstract
Teleost fish are unique among vertebrates in that phenotypic sex or onset of sex inversion can be easily manipulated by hormonal treatments. In recent years, researchers have begun reporting concentrations of synthetic and natural hormones in the environment. Although concentrations are very low (in the parts per trillion to low parts per billion), they are still of concern because of the high potency of synthetic hormones and the enhanced susceptibility of teleost fishes, especially early life stages, to hormonal exposures. In this review, we will focus on sex differentiation in teleost fishes and how these processes in fish early life stages may be impacted by environmental hormones which are known to contaminate aquatic environments. We will start by reviewing information on sources and concentrations of hormones in the environment and continue by summarizing the state of knowledge of sex differentiation in teleost gonochoristic fishes, including information on genes involved (e.g. cyp19, dmrt1, sox9 and foxl2). We will end our review with a summary of studies that have examined the effects of androgens and estrogens on fish sex differentiation after exposure of fish embryos and larvae and with ideas for future research.
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Affiliation(s)
- Jessica K Leet
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA
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82
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Mestrallet G, Bertholet-Thomas A, Ranchin B, Bouvier R, Frappaz D, Cochat P. Recurrence of a dysgerminoma in Frasier syndrome. Pediatr Transplant 2011; 15:e53-5. [PMID: 20408995 DOI: 10.1111/j.1399-3046.2010.01273.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
FS is an inherited disease characterized by male pseudohermaphroditism and glomerular involvement leading to end-stage renal disease during adolescence or early adulthood (J Pediatr 1964:64:740). The FS phenotype in 46,XY patients consists of female external genitalia, gonadal dysgenesis, high risk of gonadoblastoma, and development of renal failure in the second decade of life. FS is caused by heterozygous mutation in intron 9 of the WT1 leading to a change in splicing that results in loss of three amino acids (+KTS isoform), thus disrupting the normal ratio of the +KTS/-KTS isoforms that is critical for proper gonadal and renal development (Nat Genet 1997:17:467; Hum Mol Genet 1998:7:709). We report on a patient followed for FS revealed by acute peritoneal syndrome because of ovarian dysgerminoma. Therapeutic options had led to an unusual course with recurrent neoplastic disease after renal transplantation.
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Affiliation(s)
- Guillaume Mestrallet
- Service de Pédiatrie and Centre de Référence des Maladies Rénales Rares, Hospices civils de Lyon, Hôpital Femme Mère Enfant and Université Claude Bernard Lyon 1, Lyon, France
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83
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Abstract
Infants born with ambiguous genitalia represent a complex clinical challenge. A systematic clinical investigation aims at determining the hormone production and which anatomical structures are present in order to understand at what level the sex differentiation has been affected; chromosomal, gonadal or hormonal synthesis and action levels. The increased genetic knowledge in the field has opened up new diagnostic possibilities. Sex development requires the balanced and sequential activation of transcription factors, signaling molecules and hormones. It has recently been shown that not only testis but also normal ovarian development is an active process. Genes involved in gonadal disorders of sex development often act in a gene dosage-dependent manner, with different effects in XY or XX embryos. The management of patients with disorders of sex development, including decisions about sex of rearing, must be carried out by a specialized multidisciplinary team and include an extended genetic investigation as well as psychological considerations.
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Affiliation(s)
- M Barbaro
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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84
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Constant splice-isoform ratios in human lymphoblastoid cells support the concept of a splico-stat. Genetics 2011; 187:761-70. [PMID: 21220357 DOI: 10.1534/genetics.110.125096] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Splicing generates mature transcripts from genes in pieces in eukaryotic cells. Overwhelming evidence has accumulated that alternative routes in splicing are possible for most human and mammalian genes, thereby allowing formation of different transcripts from one gene. No function has been assigned to the majority of identified alternative splice forms, and it has been assumed that they compose inert or tolerated waste from aberrant or noisy splicing. Here we demonstrate that five human transcription units (WT1, NOD2, GNAS, RABL2A, RABL2B) have constant splice-isoform ratios in genetically diverse lymphoblastoid cell lines independent of the type of alternative splicing (exon skipping, alternative donor/acceptor, tandem splice sites) and gene expression level. Even splice events that create premature stop codons and potentially trigger nonsense-mediated mRNA decay are found at constant fractions. The analyzed alternative splicing events were qualitatively but not quantitatively conserved in corresponding chimpanzee cell lines. Additionally, subtle splicing at tandem acceptor splice sites (GNAS, RABL2A/B) was highly constrained and strongly depends on the upstream donor sequence content. These results also demonstrate that unusual and unproductive splice variants are produced in a regulated manner.
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85
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Sánchez-Sánchez AV, Camp E, Leal-Tassias A, Atkinson SP, Armstrong L, Díaz-Llopis M, Mullor JL. Nanog regulates primordial germ cell migration through Cxcr4b. Stem Cells 2010; 28:1457-64. [PMID: 20578184 DOI: 10.1002/stem.469] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of PGCs and inhibits expression of Cxcr4b in PGCs, where it normally serves as the receptor of Sdf1a to guide PGC migration. Moreover, chromatin immunoprecipitation analysis demonstrates that Ol-Nanog protein binds to the promoter region of Cxcr4b, suggesting a direct regulation of Cxcr4b by Ol-Nanog. Simultaneous overexpression of Cxcr4b mRNA and depletion of Ol-Nanog protein in PGCs rescues the migration defective phenotype induced by a loss of Ol-Nanog, whereas overexpression of Sdf1a, the ligand for Cxcr4b, does not restore proper PGC migration. These results indicate that Ol-Nanog mediates PGC migration by regulating Cxcr4b expression.
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86
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Sinha A, Sharma S, Gulati A, Sharma A, Agarwala S, Hari P, Bagga A. Frasier syndrome: early gonadoblastoma and cyclosporine responsiveness. Pediatr Nephrol 2010; 25:2171-4. [PMID: 20419325 DOI: 10.1007/s00467-010-1518-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Revised: 03/10/2010] [Accepted: 03/10/2010] [Indexed: 10/19/2022]
Abstract
Frasier syndrome is characterized by progressive glomerulopathy that is unresponsive to corticosteroids, male pseudohermaphroditism, and an increased risk of genitourinary tumors. Of 21 girls with steroid-resistant nephrotic syndrome secondary to focal segmental glomerulosclerosis (FSGS) who were screened for mutations in the WT1 gene, two showed Frasier syndrome. Both patients had donor splice-site mutations in intron 9 of the WT1 gene and a male karyotype (46, XY). Long-term therapy with cyclosporine resulted in partial remission in both cases. One patient showed foci of gonadoblastoma in the excised dysgenetic gonads. This report highlights the need for screening for mutations in the WT1 gene in girls with steroid-resistant FSGS. Patients with Frasier syndrome might benefit from early gonadectomy.
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Affiliation(s)
- Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
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87
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Abstract
The term, disorders of sexual differentiation, broadly represents a disjunction between genotype and phenotype. Phenotype in turn can refer to external or internal genital development. Disorders of sexual differentiation are determined at conception insofar as (1) the abnormal genotype is the aberrant genetic product of fertilization at the chromosomal level or (2) the abnormal phenotype results from postfertilization errors in function at the gene level, somewhere along the pathway of transcription and translation. In either event, the error is genetic, whether or not sporadic or inherited, even if the pathways have yet to be fully elucidated for a given disorder.
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88
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Li J, Ding J, Zhao D, Yu Z, Fan Q, Chen Y, Zhang H, Zhong X, Huang J, Yao Y, Xiao H. WT1 gene mutations in Chinese children with early onset nephrotic syndrome. Pediatr Res 2010; 68:155-8. [PMID: 20442690 DOI: 10.1203/pdr.0b013e3181e4c9e3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In Chinese children with steroid-resistant nephrotic syndrome (SRNS), it was reported that NPHS2 mutation was detected in 4.3%, which was lower than that in Caucasians (10-30%). However, there were no data on WT1 mutation in nephrotic syndrome (NS), especially in early-onset NS of Chinese children. Thus, a study, which enrolled 36 Chinese children with early-onset (before 3 y old) NS and steroid resistance if failing steroid therapy (early-group), was conducted. As control, 35 children with SRNS and with disease onset age after 3 y old were also analyzed (control-group). WT1 gene was examined by PCR and direct sequencing. The result showed that in the early-group 6/36 (16.7%) were detected with WT1 mutations. Further analysis according to different onset age revealed that the mutation detection rates of WT1 were 26.3% (5/19), 6.3% (1/16), and 0 (0/1) in children younger than 1 y, 1-2 y, and 2-3 y, respectively. In control-group, no WT1 (0/35) mutation was detected. WT1 mutation combined with NPHS2 variant was detected in a girl. In conclusion, WT1 mutations seemed more common in Chinese children with early-onset NS.
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Affiliation(s)
- Jianguo Li
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, People's Republic of China
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89
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Andikyan V, Taylor HS. WT1 represses HOX gene expression in the regulation of gynaecologic tumour histologic type. J Cell Mol Med 2010; 13:4522-31. [PMID: 19017365 PMCID: PMC3107857 DOI: 10.1111/j.1582-4934.2008.00574.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Homeobox genes encode transcription factors that dictate developmental identity, including that of the Mullerian tract. These genes also direct differential Mullerian transformation of the ovarian cancer cells. The homeobox gene HOXA10 controls uterine organogenesis during embryonic development and similarly is expressed in endometroid epithelial ovarian cancer. Here we confirmed aberrant regulation of HOXA10 expression in epithelial uterine and ovarian carcinomas. We identified a HOXA10 epithelial regulatory element containing an enhancer that drove HOXA10 expression specifically in gynaecologic epithelium. We further identified an adjoining dominant repressor element that restricted regulation by the epithelial enhancer to a subset of epithelial cell types. The repressor contained two functional WT1 binding sites. We identified a strong inverse correlation between HOXA10 expression and that of the Wilms’ Tumour 1 (WT1) gene in multiple benign and malignant gynaecologic tissues, suggesting functionality of the WT1 sites in the repressor. Mutation of the two WT1 binding sites abolished WT1 binding to the element as well as the ability to affect epithelial enhancer activity in reporter assays. Similarly, decreased expression of WT1 using siRNA prevented repressor activity. The Mullerian phenotype seen in ovarian cancer is dependent on gain of HOX gene expression secondary to the loss of WT1-mediated HOX repression. This suggests that Gynaecologic epithelial histologic type is regulated by WT1 expression through its selective repression of HOX genes.
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Affiliation(s)
- Vaagn Andikyan
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University, New Haven, CT, USA
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90
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Successful treatment of steroid-resistant nephrotic syndrome associated with WT1 mutations. Pediatr Nephrol 2010; 25:1285-9. [PMID: 20191369 DOI: 10.1007/s00467-010-1468-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/03/2009] [Accepted: 11/03/2009] [Indexed: 10/19/2022]
Abstract
The Wilms' tumor suppressor gene 1 (WT1) encodes a transcription factor involved in kidney and gonadal development. WT1 is also a key regulator of podocyte functions and mutations have been found in a small percentage of children with isolated or syndromal steroid-resistant nephrotic syndrome. It is commonly assumed that the nephrotic syndrome (NS) in patients with WT1 mutations is unresponsive to therapy and characterized by rapid progression to end-stage renal disease. We report long-term observations in 3 children with focal-segmental glomerulosclerosis associated with WT1 mutations and NS (2 cases) or nephrotic range proteinuria (1 case). All patients showed a favorable response to an intensified therapy consisting of cyclosporin A (CyA) in combination with induction therapy with intravenous and oral prednisone. Treatment with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers was added to the regimen at various times. As shown both by the short-term response and during long-term follow-up, this treatment resulted in clinical remission of the NS and/or significant reduction of proteinuria, while normal renal function could be maintained over many years. Thus, glomerular diseases in selected patients with mutations in genes regulating renal development and podocyte function may respond to combination therapy with CyA and corticosteroids.
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91
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Chernin G, Vega-Warner V, Schoeb DS, Heeringa SF, Ovunc B, Saisawat P, Cleper R, Ozaltin F, Hildebrandt F. Genotype/phenotype correlation in nephrotic syndrome caused by WT1 mutations. Clin J Am Soc Nephrol 2010; 5:1655-62. [PMID: 20595692 DOI: 10.2215/cjn.09351209] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES The risk of developing Wilms tumor (WT) can be present or absent in patients with nephrotic syndrome (NS) caused by WT1 mutations. Here, the genotype/phenotype correlation regarding the outcome and risk for WT in 52 patients from 51 families with NS due to WT1 mutations is described. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study followed 19 patients with mutations in intron 9 splice donor site (KTS mutations), 27 patients with missense mutations, 4 patients with nonsense mutations, 1 patient with a splice site mutation in intron 8, and 1 patient with a deletion. RESULTS Twenty-four different WT1 mutations were detected. Sixteen of the 19 patients with KTS mutations were females. These patients had isolated NS if karyotype was 46,XX and Frasier syndrome if karyotype was 46,XY. Patients with KTS mutations presented at a significantly older age and with a slower progression toward chronic kidney disease (CKD) stage 5, compared with missense mutations. Patients with nonsense mutations presented initially with WT. Six patients with missense mutations developed WT after the diagnosis of NS (interval-range from NS onset to WT of 0.1 to 1.4 years). CONCLUSIONS (1) KTS mutations cause isolated NS with absence of WT in 46,XX females. (2) KTS mutations cause Frasier syndrome with gonadoblastoma risk in 46,XY phenotypic females. (3) KTS mutations cause NS with a slower progression when compared with missense mutations. (4) Missense mutations can occur with and without WT. (5) WT1 analysis is important in young patients with NS for early detection and tumor prophylaxis.
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Affiliation(s)
- Gil Chernin
- Departments of Pediatrics, University of Michigan Health System, Ann Arbor, MI 48109-5646, USA
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92
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Wells J, Rivera MN, Kim WJ, Starbuck K, Haber DA. The predominant WT1 isoform (+KTS) encodes a DNA-binding protein targeting the planar cell polarity gene Scribble in renal podocytes. Mol Cancer Res 2010; 8:975-85. [PMID: 20571064 DOI: 10.1158/1541-7786.mcr-10-0033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
WT1 encodes a tumor suppressor first identified by its inactivation in Wilms' Tumor. Although one WT1 splicing variant encodes a well-characterized zinc finger transcription factor, little is known about the function of the most prevalent WT1 isoform, whose DNA binding domain is disrupted by a three-amino acid (KTS) insertion. Using cells that conditionally express WT1(+KTS), we undertook a genome-wide chromatin immunoprecipitation and cloning analysis to identify candidate WT1(+KTS)-regulated promoters. We identified the planar cell polarity gene Scribble (SCRB) as the first WT1(+KTS) target gene in podocytes of the kidney. WT1 and SCRB expression patterns overlap precisely in developing renal glomeruli of mice, and WT1(+KTS) binds to a 33-nucleotide region within the Scribble promoter in mouse and human cell lines and kidneys. Together, our results support a role for the predominant WT1(+KTS) isoform in transcriptional regulation and suggest a link between the WT1-dependent tumor suppressor pathway and a key component of the planar cell polarity pathway.
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Affiliation(s)
- Julie Wells
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts, USA
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93
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Abstract
Geneticists estimate that 5% to 10% of all cancers diagnosed in the pediatric age range occur in children born with a genetic mutation that directly increases their lifetime risk for neoplasia. However, despite the fact that only a fraction of cancers in children occur as a result of an identified inherited predisposition, characterizing genetic mutations responsible for increased cancer risk in such syndromes has resulted in a profound understanding of relevant molecular pathways involved in carcinogenesis and/or resistance to neoplasia. Importantly, because most cancer predisposition syndromes result in an increased risk of a small number of defined malignancies, personalized prophylactic surveillance and preventive measures can be implemented in affected patients. Lastly, many of the same genetic targets identified from cancer-prone families are mechanistically involved in the majority of sporadic cancers in adults and children, thereby underscoring the clinical relevance of knowledge gained from these defined syndromes and introducing novel therapeutic opportunities to the broader oncologic community. This review highlights the clinical and genetic features of many of the known constitutional genetic syndromes that predispose to malignancy in children and young adults.
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94
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Frasier syndrome, a potential cause of end-stage renal failure in childhood. Pediatr Nephrol 2010; 25:549-52. [PMID: 19921279 DOI: 10.1007/s00467-009-1343-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 10/20/2022]
Abstract
The diagnosis of Frasier syndrome is based on the association of male pseudohermaphroditism (as a result of gonadal dysgenesis), with steroid-resistant nephrotic syndrome due to focal and segmental glomerular sclerosis (FSGS), which progresses to end-stage renal failure (ESRF) during adolescence or adulthood. Frasier syndrome results from mutations in the Wilms' tumour suppressor gene WT1, which is responsible for alterations in male genital development and podocyte dysfunction. We describe the case of a 7-year-old girl who was referred to the paediatric emergency department with ESRF. Haemodialysis was started immediately because of severe hypertension and hyperkalaemia. In view of the fact that our patient had a past medical history of pseudohermaphroditism, we suspected that the acute presentation in ESRF may be related to a new diagnosis of Frasier syndrome. Our hypothesis was confirmed on examination of the medical records. There had been no medical follow-up for several years and, in particular, no renal imaging or functional assessment had ever been performed. This lack of surveillance explains why our patient presented with ESRF much earlier in this disease than expected and subsequently had to undergo kidney transplantation at a very young age.
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95
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Benetti E, Caridi G, Malaventura C, Dagnino M, Leonardi E, Artifoni L, Ghiggeri GM, Tosatto SCE, Murer L. A novel WT1 gene mutation in a three-generation family with progressive isolated focal segmental glomerulosclerosis. Clin J Am Soc Nephrol 2010; 5:698-702. [PMID: 20150449 DOI: 10.2215/cjn.05670809] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Wilms tumor-suppressor gene-1 (WT1) plays a key role in kidney development and function. WT1 mutations usually occur in exons 8 and 9 and are associated with Denys-Drash, or in intron 9 and are associated with Frasier syndrome. However, overlapping clinical and molecular features have been reported. Few familial cases have been described, with intrafamilial variability. Sporadic cases of WT1 mutations in isolated diffuse mesangial sclerosis or focal segmental glomerulosclerosis have also been reported. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Molecular analysis of WT1 exons 8 and 9 was carried out in five members on three generations of a family with late-onset isolated proteinuria. The effect of the detected amino acid substitution on WT1 protein's structure was studied by bioinformatics tools. RESULTS Three family members reached end-stage renal disease in full adulthood. None had genital abnormalities or Wilms tumor. Histologic analysis in two subjects revealed focal segmental glomerulosclerosis. The novel sequence variant c.1208G>A in WT1 exon 9 was identified in all of the affected members of the family. CONCLUSIONS The lack of Wilms tumor or other related phenotypes suggests the expansion of WT1 gene analysis in patients with focal segmental glomerulosclerosis, regardless of age or presence of typical Denys-Drash or Frasier syndrome clinical features. Structural analysis of the mutated protein revealed that the mutation hampers zinc finger-DNA interactions, impairing target gene transcription. This finding opens up new issues about WT1 function in the maintenance of the complex gene network that regulates normal podocyte function.
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Affiliation(s)
- Elisa Benetti
- Pediatric Nephrology, Dialysis and Transplant Unit, Department of Pediatrics, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
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96
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Subbiah V, Huff V, Wolff JEA, Ketonen L, Lang FF, Stewart J, Langford L, Herzog CE. Bilateral gonadoblastoma with dysgerminoma and pilocytic astrocytoma with WT1 GT-IVS9 mutation: A 46 XY phenotypic female with Frasier syndrome. Pediatr Blood Cancer 2009; 53:1349-51. [PMID: 19653292 DOI: 10.1002/pbc.22152] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Frasier syndrome is characterized by a 46 XY disorder of sex development, nephropathy, and increased risk for gonadoblastoma due to Wilms tumor 1(WT1) mutation in the donor splice site of intron-9, resulting in the splice form +KTS. Germ cell tumors and gonadoblastomas have been reported previously in Frasier syndrome. We present the clinical, radiological, and genetic (WT1 mutation analysis) of a 46 XY phenotypic female with Frasier syndrome with bilateral gonadoblastoma with dysgerminoma who developed pilocytic astrocytoma.
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Affiliation(s)
- Vivek Subbiah
- Department of Pediatrics, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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97
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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.
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98
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Rivers C, Flynn A, Qian X, Matthews L, Lightman S, Ray D, Norman M. Characterization of conserved tandem donor sites and intronic motifs required for alternative splicing in corticosteroid receptor genes. Endocrinology 2009; 150:4958-4967. [PMID: 19819975 PMCID: PMC4455001 DOI: 10.1210/en.2009-0346] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Alternative splicing events from tandem donor sites result in mRNA variants coding for additional amino acids in the DNA binding domain of both the glucocorticoid (GR) and mineralocorticoid (MR) receptors. We now show that expression of both splice variants is extensively conserved in mammalian species, providing strong evidence for their functional significance. An exception to the conservation of the MR tandem splice site (an A at position +5 of the MR+12 donor site in the mouse) was predicted to decrease U1 small nuclear RNA binding. In accord with this prediction, we were unable to detect the MR+12 variant in this species. The one exception to the conservation of the GR tandem splice site, an A at position +3 of the platypus GRgamma donor site that was predicted to enhance binding of U1 snRNA, was unexpectedly associated with decreased expression of the variant from the endogenous gene as well as a minigene. An intronic pyrimidine motif present in both GR and MR genes was found to be critical for usage of the downstream donor site, and overexpression of TIA1/TIAL1 RNA binding proteins, which are known to bind such motifs, led to a marked increase in the proportion of GRgamma and MR+12. These results provide striking evidence for conservation of a complex splicing mechanism that involves processes other than stochastic spliceosome binding and identify a mechanism that would allow regulation of variant expression.
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Affiliation(s)
- Caroline Rivers
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
| | - Andrea Flynn
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
| | - Xiaoxiao Qian
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
| | - Laura Matthews
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
| | - Stafford Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
| | - David Ray
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
| | - Michael Norman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom
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Andrade JGRD, Guaragna MS, Soardi FC, Guerra-Júnior G, Mello MPD, Maciel-Guerra AT. Clinical and genetic findings of five patients with WT1-related disorders. ACTA ACUST UNITED AC 2009; 52:1236-43. [PMID: 19169475 DOI: 10.1590/s0004-27302008000800006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Accepted: 10/14/2008] [Indexed: 11/22/2022]
Abstract
AIM To present phenotypic variability of WT1-related disorders. METHODS Description of clinical and genetic features of five 46,XY patients with WT1 anomalies. RESULTS Patient 1: newborn with genital ambiguity; he developed Wilms tumor (WT) and chronic renal disease and died at the age of 10 months; the heterozygous 1186G>A mutation compatible with Denys-Drash syndrome was detected in this child. Patients 2 and 3: adolescents with chronic renal disease, primary amenorrhea and hypergonadotrophic hypogonadism; patient 2 had a gonadoblastoma. The heterozygous IVS9+4, C>T mutation, compatible with Frasier syndrome was detected. Patient 4: 9-year-old boy with aniridia, genital ambiguity, dysmorphisms and mental deficiency; a heterozygous 11p deletion, compatible with WAGR syndrome was detected. Patient 5: 2 months old, same diagnosis of patient 4; he developed WT at the age of 8 months. CONCLUSIONS Constitutional abnormalities of WT1 cause gonadal and renal anomalies and predisposition to neoplasia and must be investigated in patients with ambiguous genitalia, chronic renal disease and(or) Wilms tumors; primary amenorrhea with chronic renal disease; and aniridia, genital ambiguity and dysmorphisms.
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Monogene Ursachen des nephrotischen Syndroms. Monatsschr Kinderheilkd 2009. [DOI: 10.1007/s00112-008-1866-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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