Zebrafish as a model to investigate a biallelic gain-of-function variant in MSGN1, associated with a novel skeletal dysplasia syndrome.

Autor: Koparir A; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany., Lekszas C; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany., Keseroglu K; Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA., Rose T; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany., Rappl L; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany., Rad A; Cellular and Molecular Research Centre, Sabzevar University of Medical Sciences, Sabzevar, Iran., Maroofian R; Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK., Narendran N; University of Cincinnati College of Medicine, Cincinnati, OH, USA., Hasanzadeh A; Cellular and Molecular Research Centre, Sabzevar University of Medical Sciences, Sabzevar, 009851, Iran., Karimiani EG; Department of Medical Genetics, Next Generation Genetic Polyclinic, Mashhad, Iran., Boschann F; Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin, Germany.; Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany., Kornak U; Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin, Germany.; Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany., Klopocki E; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany., Özbudak EM; Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA., Vona B; Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany.; Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany., Haaf T; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany., Liedtke D; Institute of Human Genetics, Julius-Maximilians-Universität Würzburg, Biozentrum, Am Hubland, 97074, Würzburg, Germany. Daniel.liedtke@uni-wuerzburg.de.
Jazyk: angličtina
Zdroj: Human genomics [Hum Genomics] 2024 Mar 06; Vol. 18 (1), pp. 23. Date of Electronic Publication: 2024 Mar 06.
DOI: 10.1186/s40246-024-00593-w
Abstrakt: Background/objectives: Rare genetic disorders causing specific congenital developmental abnormalities often manifest in single families. Investigation of disease-causing molecular features are most times lacking, although these investigations may open novel therapeutic options for patients. In this study, we aimed to identify the genetic cause in an Iranian patient with severe skeletal dysplasia and to model its molecular function in zebrafish embryos.
Results: The proband displays short stature and multiple skeletal abnormalities, including mesomelic dysplasia of the arms with complete humero-radio-ulna synostosis, arched clavicles, pelvic dysplasia, short and thin fibulae, proportionally short vertebrae, hyperlordosis and mild kyphosis. Exome sequencing of the patient revealed a novel homozygous c.374G > T, p.(Arg125Leu) missense variant in MSGN1 (NM_001105569). MSGN1, a basic-Helix-Loop-Helix transcription factor, plays a crucial role in formation of presomitic mesoderm progenitor cells/mesodermal stem cells during early developmental processes in vertebrates. Initial in vitro experiments show protein stability and correct intracellular localization of the novel variant in the nucleus and imply retained transcription factor function. To test the pathogenicity of the detected variant, we overexpressed wild-type and mutant msgn1 mRNA in zebrafish embryos and analyzed tbxta (T/brachyury/ntl). Overexpression of wild-type or mutant msgn1 mRNA significantly reduces tbxta expression in the tailbud compared to control embryos. Mutant msgn1 mRNA injected embryos depict a more severe effect, implying a gain-of-function mechanism. In vivo analysis on embryonic development was performed by clonal msgn1 overexpression in zebrafish embryos further demonstrated altered cell compartments in the presomitic mesoderm, notochord and pectoral fin buds. Detection of ectopic tbx6 and bmp2 expression in these embryos hint to affected downstream signals due to Msgn1 gain-of-function.
Conclusion: In contrast to loss-of-function effects described in animal knockdown models, gain-of-function of MSGN1 explains the only mildly affected axial skeleton of the proband and rather normal vertebrae. In this context we observed notochord bending and potentially disruption of pectoral fin buds/upper extremity after overexpression of msgn1 in zebrafish embryos. The latter might result from Msgn1 function on mesenchymal stem cells or on chondrogenesis in these regions. In addition, we detected ectopic tbx6 and bmp2a expression after gain of Msgn1 function in zebrafish, which are interconnected to short stature, congenital scoliosis, limb shortening and prominent skeletal malformations in patients. Our findings highlight a rare, so far undescribed skeletal dysplasia syndrome associated with a gain-of-function mutation in MSGN1 and hint to its molecular downstream effectors.
(© 2024. The Author(s).)
Databáze: MEDLINE
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