Gain-of-function variants in the ion channel gene TRPM3 underlie a spectrum of neurodevelopmental disorders
- INSERM UMR 1163, France
- KU Leuven, Belgium
- Hôpitaux Universitaires Paris-Ouest, France
- Centre Hospitalier Universitaire d'Angers, France
- Translational Genomics Research Institute, United States
- Charité - Universitäts medizin Berlin, Germany
- Essen University Hospital, United States
- University Hospital Southampton NHS Foundation Trust, United Kingdom
- Children's Hospital of Philadelphia, United States
- Charité - Universitätsmedizin Berlin, Germany
- Rutgers, The State University of New Jersey, United States
- University of Liège, Belgium
- Salisbury District Hospital, United Kingdom
- Centre Hospitalier Universitaire de Besançon, France
- University of Ottawa, Canada
- VIB-KU Leuven Center for Brain & Disease Research, Belgium
Abstract
TRPM3 is a temperature- and neurosteroid-sensitive plasma membrane cation channel expressed in a variety of neuronal and non-neuronal cells. Recently, rare de novo variants in TRPM3 were identified in individuals with developmental and epileptic encephalopathy (DEE), but the link between TRPM3 activity and neuronal disease remains poorly understood. We previously reported that two disease-associated variants in TRPM3 lead to a gain of channel function (Van Hoeymissen et al., 2020; Zhao et al., 2020). Here, we report a further ten patients carrying one of seven additional heterozygous TRPM3 missense variants. These patients present with a broad spectrum of neurodevelopmental symptoms, including global developmental delay, intellectual disability, epilepsy, musculo-skeletal anomalies, and altered pain perception. We describe a cerebellar phenotype with ataxia or severe hypotonia, nystagmus, and cerebellar atrophy in more than half of the patients. All disease-associated variants exhibited a robust gain-of-function phenotype, characterized by increased basal activity leading to cellular calcium overload and by enhanced responses to the neurosteroid ligand pregnenolone sulphate, when co-expressed with wild-type TRPM3 in mammalian cells. The antiseizure medication primidone, a known TRPM3 antagonist, reduced the increased basal activity of all mutant channels. These findings establish gain-of-function of TRPM3 as the cause of a spectrum of autosomal dominant neurodevelopmental disorders with frequent cerebellar involvement in humans, and provide support for the evaluation of TRPM3 antagonists as a potential therapy.
Data availability
Raw data for the following figures are made available via figshare (https://doi.org/10.6084/m9.figshare.21799604): Figure 1 - Figure Supplement 1; Figure 3; Figure 3 - Figure Supplement 1, 2, 3 and 4; Figure 4; Figure 4 - Figure Supplement 1, 2 and 3.
-
Data of Evelien Van Hoeymissen for manuscript "Gain-of-function variants in the ion channel gene TRPM3 underlie a spectrum of neurodevelopmental disorders"https://doi.org/10.6084/m9.figshare.21799604.
Article and author information
Author details
Evelien Van Hoeymissen
Funding
Flanders' FOOD (G.0D1417N)
- Joris Vriens
Flanders' FOOD (G.084515N)
- Joris Vriens
Flanders' FOOD (G.0A6719N)
- Joris Vriens
Flanders' FOOD (11E782)
- Evelien Van Hoeymissen
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Andres Jara-Oseguera, The University of Texas at Austin, United States
Ethics
Human subjects: The study was performed in accordance with the guidelines specified by the institutional review boards and ethics committees at each institution. Information of institutional protocols are provided in the section of Material & Methods. All parents agreed on sharing and publicing the patients' information.Patients information:patient 1, 3, 4, 7: Written informed consent was obtained from the parents of the probands for molecular genetic analysis and possible publication of the anonymized clinical data. The study was done in accordance with local research and ethics requirements.patient 2: Parents signed an informed consent, received a genetic counselling before and after the analysis, and the genetic study was performed in accordance with German and French ethical requirements and laws.patient 5: UK ethical approval by the Cambridge South Research Ethics Committee (10/H0305/83)patient 6: outine clinical care within the UK National Health Service, and so no specific institutional ethical approval was requiredpatient 8: Declaration of Helsinki with local approval by the Children's Hospital of Philadelphia (CHOP) Institutional Review Board (IRB 15-12226).patient 9: The participating family signed the IRB research protocol of the University of Pennsylvania division of Neurologypatient 10: The study protocol and consent documents were approved by the Western Institutional Review Board (WIRB # 20120789). The retrospective analysis of epilepsy patient data was approved by the local ethics committees of the Charité (approval no. EA2/084/18)
Version history
- Received: June 13, 2022
- Accepted: December 7, 2022
- Accepted Manuscript published: January 17, 2023 (version 1)
- Accepted Manuscript updated: January 19, 2023 (version 2)
- Version of Record published: January 30, 2023 (version 3)
Copyright
© 2023, Burglen et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,492
- views
-
- 459
- downloads
-
- 8
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Gain-of-function variants in the ion channel gene TRPM3 underlie a spectrum of neurodevelopmental disorders
eLife 12:e81032.
https://doi.org/10.7554/eLife.81032
Further reading
-
- Cell Biology
- Neuroscience
Mutations in Drosophila Swiss cheese (SWS) gene or its vertebrate orthologue neuropathy target esterase (NTE) lead to progressive neuronal degeneration in flies and humans. Despite its enzymatic function as a phospholipase is well established, the molecular mechanism responsible for maintaining nervous system integrity remains unclear. In this study, we found that NTE/SWS is present in surface glia that forms the blood-brain barrier (BBB) and that NTE/SWS is important to maintain its structure and permeability. Importantly, BBB glia-specific expression of Drosophila NTE/SWS or human NTE in the sws mutant background fully rescues surface glial organization and partially restores BBB integrity, suggesting a conserved function of NTE/SWS. Interestingly, sws mutant glia showed abnormal organization of plasma membrane domains and tight junction rafts accompanied by the accumulation of lipid droplets, lysosomes, and multilamellar bodies. Since the observed cellular phenotypes closely resemble the characteristics described in a group of metabolic disorders known as lysosomal storage diseases (LSDs), our data established a novel connection between NTE/SWS and these conditions. We found that mutants with defective BBB exhibit elevated levels of fatty acids, which are precursors of eicosanoids and are involved in the inflammatory response. Also, as a consequence of a permeable BBB, several innate immunity factors are upregulated in an age-dependent manner, while BBB glia-specific expression of NTE/SWS normalizes inflammatory response. Treatment with anti-inflammatory agents prevents the abnormal architecture of the BBB, suggesting that inflammation contributes to the maintenance of a healthy brain barrier. Considering the link between a malfunctioning BBB and various neurodegenerative diseases, gaining a deeper understanding of the molecular mechanisms causing inflammation due to a defective BBB could help to promote the use of anti-inflammatory therapies for age-related neurodegeneration.
-
- Cancer Biology
- Cell Biology
Enhanced protein synthesis is a crucial molecular mechanism that allows cancer cells to survive, proliferate, metastasize, and develop resistance to anti-cancer treatments, and often arises as a consequence of increased signaling flux channeled to mRNA-bearing eukaryotic initiation factor 4F (eIF4F). However, the post-translational regulation of eIF4A1, an ATP-dependent RNA helicase and subunit of the eIF4F complex, is still poorly understood. Here, we demonstrate that IBTK, a substrate-binding adaptor of the Cullin 3-RING ubiquitin ligase (CRL3) complex, interacts with eIF4A1. The non-degradative ubiquitination of eIF4A1 catalyzed by the CRL3IBTK complex promotes cap-dependent translational initiation, nascent protein synthesis, oncogene expression, and cervical tumor cell growth both in vivo and in vitro. Moreover, we show that mTORC1 and S6K1, two key regulators of protein synthesis, directly phosphorylate IBTK to augment eIF4A1 ubiquitination and sustained oncogenic translation. This link between the CRL3IBTK complex and the mTORC1/S6K1 signaling pathway, which is frequently dysregulated in cancer, represents a promising target for anti-cancer therapies.
