Genetic Variants in ARHGEF6 Cause Congenital Anomalies of the Kidneys and Urinary Tract in Humans, Mice, and Frogs

Verena Klämbt, Florian Buerger, Chunyan Wang, Thomas Naert, Karin Richter, Theresa Nauth, Anna Carina Weiss, Tobias Sieckmann, Ethan Lai, Dervla M. Connaughton, Steve Seltzsam, Nina Mann, Amar J. Majmundar, Chen Han W. Wu, Ana C. Onuchic-Whitford, Shirlee Shril, Sophia Schneider, Luca Schierbaum, Rufeng Dai, Mir Reza BekheirniaMarieke Joosten, Omer Shlomovitz, Asaf Vivante, Ehud Banne, Shrikant Mane, Richard P. Lifton, Karin M. Kirschner, Andreas Kispert, Georg Rosenberger, Klaus Dieter Fischer, Soeren S. Lienkamp, Mirjam M.P. Zegers, Friedhelm Hildebrandt*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Significance StatementAbout 40 disease genes have been described to date for isolated CAKUT, the most common cause of CKD during childhood. However, mutations in these genes explain only 20% of cases. The authors performed exome sequencing in an international cohort of individuals with CAKUT. They identified genetic variants in ARHGEF6 (a gene on the X chromosome in humans that encodes a guanine nucleotide exchange factor) as a potential novel cause of this disease. Using a multifaceted approach, including cellular and independent animal models, they found evidence that ARHGEF6 variants cause disease, potentially via dysregulation of integrin/parvin/RAC1/CDC42 signaling. These findings further link ARHGEF6 function to integrin/parvin/RAC1/CDC42 signaling, thereby strengthening this pathway's relevance for renal development.BackgroundAbout 40 disease genes have been described to date for isolated CAKUT, the most common cause of childhood CKD. However, these genes account for only 20% of cases. ARHGEF6, a guanine nucleotide exchange factor that is implicated in biologic processes such as cell migration and focal adhesion, acts downstream of integrin-linked kinase (ILK) and parvin proteins. A genetic variant of ILK that causes murine renal agenesis abrogates the interaction of ILK with a murine focal adhesion protein encoded by Parva, leading to CAKUT in mice with this variant.MethodsTo identify novel genes that, when mutated, result in CAKUT, we performed exome sequencing in an international cohort of 1265 families with CAKUT. We also assessed the effects in vitro of wild-type and mutant ARHGEF6 proteins, and the effects of Arhgef6 deficiency in mouse and frog models.ResultsWe detected six different hemizygous variants in the gene ARHGEF6 (which is located on the X chromosome in humans) in eight individuals from six families with CAKUT. In kidney cells, overexpression of wild-type ARHGEF6 - but not proband-derived mutant ARHGEF6 - increased active levels of CDC42/RAC1, induced lamellipodia formation, and stimulated PARVA-dependent cell spreading. ARHGEF6-mutant proteins showed loss of interaction with PARVA. Three-dimensional Madin-Darby canine kidney cell cultures expressing ARHGEF6-mutant proteins exhibited reduced lumen formation and polarity defects. Arhgef6 deficiency in mouse and frog models recapitulated features of human CAKUT.ConclusionsDeleterious variants in ARHGEF6 may cause dysregulation of integrin-parvin-RAC1/CDC42 signaling, thereby leading to X-linked CAKUT.

Original languageEnglish
Pages (from-to)273-290
Number of pages18
JournalJournal of the American Society of Nephrology : JASN
Volume34
Issue number2
DOIs
StatePublished - 1 Feb 2023

Funding

FundersFunder number
Berlin Institute of Health at Charité
UM1HG006504 Yale Center for Mendelian GenomicsU24 HG008956
National Institutes of Health5R01DK088767-09, F32 DK122766, 1K08DK125768-01A1, 5K12HD052896-13, 5R01DK076683-13
National Institutes of Health
National Human Genome Research Institute
American Society of Nephrology
ACMG Foundation for Genetic and Genomic Medicine
Wilhelm Sander-Stiftung2018.015.1
Wilhelm Sander-Stiftung
H2020 Marie Skłodowska-Curie Actions891127
H2020 Marie Skłodowska-Curie Actions
Iowa Science Foundation2773/19
Iowa Science Foundation
Manton Center for Orphan Disease Research, Boston Children's Hospital
Deutsche Forschungsgemeinschaft394046635, 403877094, 404527522, 442070894
Deutsche Forschungsgemeinschaft
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Bundesministerium für Bildung und Forschung01GM1902E
Bundesministerium für Bildung und Forschung
Charité – Universitätsmedizin Berlin
Else Kröner-Fresenius-Stiftung
Horizon 2020
Berlin Institute of Health
Swiss National Centre of Competence in Research Kidney Control of Homeostasis310030_189102/1
Swiss National Centre of Competence in Research Kidney Control of Homeostasis

    Keywords

    • CAKUT
    • development
    • monogenic kidney disease
    • pediatric

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