1
|
Javed S, Chang YT, Cho Y, Lee YJ, Chang HC, Haque M, Lin YC, Huang WH. Smith-Magenis syndrome protein RAI1 regulates body weight homeostasis through hypothalamic BDNF-producing neurons and neurotrophin downstream signalling. eLife 2023; 12:RP90333. [PMID: 37956053 PMCID: PMC10642964 DOI: 10.7554/elife.90333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023] Open
Abstract
Retinoic acid-induced 1 (RAI1) haploinsufficiency causes Smith-Magenis syndrome (SMS), a genetic disorder with symptoms including hyperphagia, hyperlipidemia, severe obesity, and autism phenotypes. RAI1 is a transcriptional regulator with a pan-neural expression pattern and hundreds of downstream targets. The mechanisms linking neural Rai1 to body weight regulation remain unclear. Here we find that hypothalamic brain-derived neurotrophic factor (BDNF) and its downstream signalling are disrupted in SMS (Rai1+/-) mice. Selective Rai1 loss from all BDNF-producing cells or from BDNF-producing neurons in the paraventricular nucleus of the hypothalamus (PVH) induced obesity in mice. Electrophysiological recordings revealed that Rai1 ablation decreased the intrinsic excitability of PVHBDNF neurons. Chronic treatment of SMS mice with LM22A-4 engages neurotrophin downstream signalling and delayed obesity onset. This treatment also partially rescued disrupted lipid profiles, insulin intolerance, and stereotypical repetitive behaviour in SMS mice. These data argue that RAI1 regulates body weight and metabolic function through hypothalamic BDNF-producing neurons and that targeting neurotrophin downstream signalling might improve associated SMS phenotypes.
Collapse
Affiliation(s)
- Sehrish Javed
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Ya-Ting Chang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Yoobin Cho
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Yu-Ju Lee
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Hao-Cheng Chang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Minza Haque
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Yu Cheng Lin
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| | - Wei-Hsiang Huang
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill UniversityMontréalCanada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health CentreMontréalCanada
| |
Collapse
|
2
|
Linders CC, van Eeghen AM, Zinkstok JR, van den Boogaard MJ, Boot E. Intellectual and Behavioral Phenotypes of Smith-Magenis Syndrome: Comparisons between Individuals with a 17p11.2 Deletion and Pathogenic RAI1 Variant. Genes (Basel) 2023; 14:1514. [PMID: 37628566 PMCID: PMC10453904 DOI: 10.3390/genes14081514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/22/2023] [Accepted: 07/23/2023] [Indexed: 08/27/2023] Open
Abstract
AIM Smith-Magenis syndrome (SMS) is a rare genetic neurodevelopmental disorder caused by a 17p11.2 deletion or pathogenic variant in the RAI1 gene. SMS is associated with developmental delay, intellectual disability (ID), and major sleep and behavioral disturbances. To explore how genetic variants may affect intellectual functioning and behavior, we compared intellectual and behavioral phenotypes between individuals with a 17p11.2 deletion and pathogenic RAI1 variant. METHOD We reviewed available clinical records from individuals (aged 0-45 years) with SMS, ascertained through a Dutch multidisciplinary SMS specialty clinic. RESULTS We included a total of 66 individuals (n = 47, 71.2% with a 17p11.2 deletion and n = 19, 28.8% with a pathogenic RAI1 variant) for whom data were available on intellectual functioning, severity of ID (n = 53), and behavioral problems assessed with the Child Behavior Checklist (CBCL, n = 39). Median full-scale IQ scores were lower (56.0 vs. 73.5, p = 0.001) and the proportion of individuals with more severe ID was higher (p = 0.01) in the 17p11.2 deletion group. Median total CBCL 6-18 scores (73.5 vs. 66.0, p = 0.02) and scores on the sub-scales somatic complaints (68.0 vs. 57.0, p = 0.001), withdrawn/depressed behavior (69.5 vs. 55.0, p = 0.02), and internalizing behavior (66.0 vs. 55.0, p = 0.002) were higher in the RAI1 group. CONCLUSION The results of this study suggest that 17p11.2 deletions are associated with a lower level of intellectual functioning and less internalizing of problems compared to pathogenic RAI1 variants. The findings of this study may contribute to personalized-management strategies in individuals with SMS.
Collapse
Affiliation(s)
- Cathelijne C. Linders
- Advisium, ’s Heeren Loo, 3818 LA Amersfoort, The Netherlands
- Department of Genetics, University Medical Centre Utrecht, 3584 CX Utrecht, The Netherlands
| | - Agnies M. van Eeghen
- Advisium, ’s Heeren Loo, 3818 LA Amersfoort, The Netherlands
- Department of Pediatrics, Emma Children’s Hospital, Amsterdam, University Medical Center, 1105 AZ Amsterdam, The Netherlands
| | - Janneke R. Zinkstok
- Department of Psychiatry, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands
- Karakter Child and Adolescent Psychiatry, 6501 BB Nijmegen, The Netherlands
- Department of Psychiatry and Brain Center, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | | | - Erik Boot
- Advisium, ’s Heeren Loo, 3818 LA Amersfoort, The Netherlands
- The Dalglish Family 22q Clinic, University Health Network, Toronto, ON M5G 2C4, Canada
- Department of Psychiatry & Neuropsychology, Maastricht University, 6200 AB Maastricht, The Netherlands
| |
Collapse
|
3
|
Yu R, Liu L, Chen C, Lin ZJ, Xu JM, Fan LL. A de novo mutation (p.S1419F) of Retinoic acid induced 1 is responsible for a patient with Smith-Magenis syndrome exhibiting schizophrenia. Gene 2023; 851:147028. [DOI: 10.1016/j.gene.2022.147028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 10/16/2022] [Accepted: 10/28/2022] [Indexed: 11/08/2022]
|
4
|
Loss of Rai1 enhances hippocampal excitability and epileptogenesis in mouse models of Smith-Magenis syndrome. Proc Natl Acad Sci U S A 2022; 119:e2210122119. [PMID: 36256819 PMCID: PMC9618093 DOI: 10.1073/pnas.2210122119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Smith–Magenis syndrome (SMS) is a neurodevelopmental disorder associated with autism and epileptic seizures. SMS is caused by losing one copy of the gene encoding retinoic acid induced 1 (RAI1), a ubiquitously expressed transcriptional regulator. To pinpoint brain regions and cell types contributing to neuronal hyperexcitability in SMS, we combined electrophysiology and three-dimensional imaging of Fos expression in the intact mouse brain. We found that Rai1-deficient hippocampal dentate gyrus granule cells (dGCs) show increased intrinsic excitability and enhanced glutamatergic synaptic transmission. Our findings indicate that Rai1 safeguards the hippocampal network from hyperexcitability and could help explain abnormal brain activity in SMS. Hyperexcitability of brain circuits is a common feature of autism spectrum disorders (ASDs). Genetic deletion of a chromatin-binding protein, retinoic acid induced 1 (RAI1), causes Smith–Magenis syndrome (SMS). SMS is a syndromic ASD associated with intellectual disability, autistic features, maladaptive behaviors, overt seizures, and abnormal electroencephalogram (EEG) patterns. The molecular and neural mechanisms underlying abnormal brain activity in SMS remain unclear. Here we show that panneural Rai1 deletions in mice result in increased seizure susceptibility and prolonged hippocampal seizure duration in vivo and increased dentate gyrus population spikes ex vivo. Brain-wide mapping of neuronal activity pinpointed selective cell types within the limbic system, including the hippocampal dentate gyrus granule cells (dGCs) that are hyperactivated by chemoconvulsant administration or sensory experience in Rai1-deficient brains. Deletion of Rai1 from glutamatergic neurons, but not from gamma-aminobutyric acidergic (GABAergic) neurons, was responsible for increased seizure susceptibility. Deleting Rai1 from the Emx1Cre-lineage glutamatergic neurons resulted in abnormal dGC properties, including increased excitatory synaptic transmission and increased intrinsic excitability. Our work uncovers the mechanism of neuronal hyperexcitability in SMS by identifying Rai1 as a negative regulator of dGC intrinsic and synaptic excitability.
Collapse
|
5
|
Rinaldi B, Villa R, Sironi A, Garavelli L, Finelli P, Bedeschi MF. Smith-Magenis Syndrome—Clinical Review, Biological Background and Related Disorders. Genes (Basel) 2022; 13:genes13020335. [PMID: 35205380 PMCID: PMC8872351 DOI: 10.3390/genes13020335] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 02/06/2023] Open
Abstract
Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by distinctive physical features, developmental delay, cognitive impairment, and a typical behavioral phenotype. SMS is caused by interstitial 17p11.2 deletions (90%), encompassing multiple genes and including the retinoic acid-induced 1 gene (RAI1), or by pathogenic variants in RAI1 itself (10%). RAI1 is a dosage-sensitive gene expressed in many tissues and acting as transcriptional regulator. The majority of individuals exhibit a mild-to-moderate range of intellectual disability. The behavioral phenotype includes significant sleep disturbance, stereotypes, maladaptive and self-injurious behaviors. In this review, we summarize current clinical knowledge and therapeutic approaches. We further discuss the common biological background shared with other conditions commonly retained in differential diagnosis.
Collapse
Affiliation(s)
- Berardo Rinaldi
- Clinical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (B.R.); (R.V.)
| | - Roberta Villa
- Clinical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (B.R.); (R.V.)
| | - Alessandra Sironi
- Experimental Research Laboratory of Medical Cytogenetics and Molecular Genetics, Istituto Auxologico Italiano, IRCCS, 20145 Milan, Italy; (A.S.); (P.F.)
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Segrate, 20090 Milan, Italy
| | - Livia Garavelli
- Clinical Genetics Unit, Azienda USL-IRCCS of Reggio Emilia, 42123 Reggio Emilia, Italy;
| | - Palma Finelli
- Experimental Research Laboratory of Medical Cytogenetics and Molecular Genetics, Istituto Auxologico Italiano, IRCCS, 20145 Milan, Italy; (A.S.); (P.F.)
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Segrate, 20090 Milan, Italy
| | - Maria Francesca Bedeschi
- Clinical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (B.R.); (R.V.)
- Correspondence:
| |
Collapse
|
6
|
Müller AR, Zinkstok JR, Rommelse NNJ, van de Ven PM, Roes KCB, Wijburg FA, de Rooij-Askes E, Linders C, Boot E, van Eeghen AM. Methylphenidate for attention-deficit/hyperactivity disorder in patients with Smith-Magenis syndrome: protocol for a series of N-of-1 trials. Orphanet J Rare Dis 2021; 16:380. [PMID: 34496899 PMCID: PMC8424817 DOI: 10.1186/s13023-021-02003-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 08/24/2021] [Indexed: 12/29/2022] Open
Abstract
Background Smith–Magenis syndrome (SMS) is a rare genetic neurodevelopmental disorder characterized by intellectual disability and severe behavioural and sleep disturbances. Often, patients with SMS are diagnosed with attention-deficit/hyperactivity disorder (ADHD). However, the effectiveness of methylphenidate (MPH), the first-line pharmacological treatment for ADHD, in patients with SMS is unclear. Our objective is to examine the effectiveness of MPH for ADHD symptoms in individuals with SMS, proposing an alternative trial design as traditional randomized controlled trials are complex in these rare and heterogeneous patient populations. Methods and analysis We will initiate an N-of-1 series of double-blind randomized and placebo-controlled multiple crossover trials in six patients aged ≥ 6 years with a genetically confirmed SMS diagnosis and a multidisciplinary established ADHD diagnosis, according to a power analysis based on a summary measures analysis of the treatment effect. Each N-of-1 trial consists of a baseline period, dose titration phase, three cycles each including randomized intervention, placebo and washout periods, and follow-up. The intervention includes twice daily MPH (doses based on age and body weight). The primary outcome measure will be the subscale hyperactivity/inattention of the Strengths and Difficulties Questionnaire (SDQ), rated daily. Secondary outcome measures are the shortened version of the Emotion Dysregulation Inventory (EDI) reactivity index, Goal Attainment Scaling (GAS), and the personal questionnaire (PQ). Statistical analysis will include a mixed model analysis. All subjects will receive an assessment of their individual treatment effect and data will be aggregated to investigate the effectiveness of MPH for ADHD in SMS at a population level. Conclusions This study will provide information on the effectiveness of MPH for ADHD in SMS, incorporating personalized outcome measures. This protocol presents the first properly powered N-of-1 study in a rare genetic neurodevelopmental disorder, providing a much-needed bridge between science and practice to optimize evidence-based and personalized care. Trial registration This study is registered in the Netherlands Trial Register (NTR9125).
Collapse
Affiliation(s)
- A R Müller
- Advisium, 's Heeren Loo, Amersfoort, the Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - J R Zinkstok
- Department of Psychiatry and Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands
| | - N N J Rommelse
- Karakter, Child and Adolescent Psychiatry, Nijmegen, The Netherlands.,Department of Psychiatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - P M van de Ven
- Department of Epidemiology and Data Science, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - K C B Roes
- Department of Health Evidence, Biostatistics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - F A Wijburg
- Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | | | - C Linders
- Advisium, 's Heeren Loo, Amersfoort, the Netherlands
| | - E Boot
- Advisium, 's Heeren Loo, Amersfoort, the Netherlands.,Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands.,The Dalglish Family 22Q Clinic, University Health Network, Toronto, ON, Canada
| | - A M van Eeghen
- Advisium, 's Heeren Loo, Amersfoort, the Netherlands. .,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, Amsterdam, The Netherlands.
| |
Collapse
|
7
|
Javed S, Lee YJ, Xu J, Huang WH. Temporal dissection of Rai1 function reveals brain-derived neurotrophic factor as a potential therapeutic target for Smith-Magenis syndrome. Hum Mol Genet 2021; 31:275-288. [PMID: 34463714 DOI: 10.1093/hmg/ddab245] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 08/02/2021] [Accepted: 08/20/2021] [Indexed: 12/17/2022] Open
Abstract
Haploinsufficiency of RAI1 is responsible for Smith-Magenis Syndrome (SMS), a childhood neurodevelopmental disorder associated with hyperphagia, obesity, and autistic features. We previously showed that constitutive inactivation of one or both copies of Rai1 in the germline or developing brain induces SMS-like neurobehavioral deficits and obesity in mice. By contrast, the postnatal function of Rai1 is unclear. Here, we globally deleted one or both copies of Rai1 during two postnatal developmental windows by generating an inducible Rai1 knockout mouse model. We found that delayed Rai1 deletion at 3 or 8 weeks of age had no effect on neurobehavioral functions but resulted in adult-onset obesity and decreased expression of brain-derived neurotrophic factor (Bdnf) in the hypothalamus. Remarkably, genetic overexpression of human Bdnf in Rai1 heterozygous mice reversed SMS-like obesity, hyperphagia, metabolic syndrome-like features, and hyposociability. Increasing Bdnf signaling in the paraventricular nucleus of the hypothalamus (PVH) or the ventromedial nucleus of the hypothalamus (VMH) was sufficient to mediate the anti-obesity effect. Our work identifies the function of Rai1 in different temporal windows after birth and provides in vivo evidence that increasing Bdnf signaling is therapeutically effective in a preclinical mouse model of SMS.
Collapse
Affiliation(s)
- Sehrish Javed
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, McGill University, Québec H3G 1A3, Canada.,Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec H3G 1A3, Canada
| | - Yu-Ju Lee
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, McGill University, Québec H3G 1A3, Canada.,Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec H3G 1A3, Canada
| | - Jin Xu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wei-Hsiang Huang
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, McGill University, Québec H3G 1A3, Canada.,Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montréal, Québec H3G 1A3, Canada
| |
Collapse
|