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Nucleic Acids Research Apr 2024Interval-training activities induce adaptive cellular changes without altering their fundamental identity, but the precise underlying molecular mechanisms are not fully...
Interval-training activities induce adaptive cellular changes without altering their fundamental identity, but the precise underlying molecular mechanisms are not fully understood. In this study, we demonstrate that interval-training depolarization (ITD) of pituitary cells triggers distinct adaptive or homeostatic splicing responses of alternative exons. This occurs while preserving the steady-state expression of the Prolactin and other hormone genes. The nature of these splicing responses depends on the exon's DNA methylation status, the methyl-C-binding protein MeCP2 and its associated CA-rich motif-binding hnRNP L. Interestingly, the steady expression of the Prolactin gene is also reliant on MeCP2, whose disruption leads to exacerbated multi-exon aberrant splicing and overexpression of the hormone gene transcripts upon ITD, similar to the observed hyperprolactinemia or activity-dependent aberrant splicing in Rett Syndrome. Therefore, epigenetic control is crucial for both adaptive and homeostatic splicing and particularly the steady expression of the Prolactin hormone gene during ITD. Disruption in this regulation may have significant implications for the development of progressive diseases.
PubMed: 38661216
DOI: 10.1093/nar/gkae311 -
BioRxiv : the Preprint Server For... Apr 2024Rett syndrome (RTT) is a neurodevelopmental disorder that is caused by loss-of-function mutations in the ( ) gene. RTT patients experience a myriad of debilitating...
Rett syndrome (RTT) is a neurodevelopmental disorder that is caused by loss-of-function mutations in the ( ) gene. RTT patients experience a myriad of debilitating symptoms, which include respiratory phenotypes that are often associated with lethality. Our previous work established that expression of the M muscarinic acetylcholine receptor (mAchR) is decreased in RTT autopsy samples, and that potentiation of the M receptor improves apneas in a mouse model of RTT; however, the population of neurons driving this rescue is unclear. Loss of Mecp2 correlates with excessive neuronal activity in cardiorespiratory nuclei. Since M is found on cholinergic interneurons, we hypothesized that M -potentiating compounds decrease apnea frequency by tempering brainstem hyperactivity. To test this, and mice were screened for apneas before and after administration of the M positive allosteric modulator (PAM) VU0453595 (VU595). Brains from the same mice were then imaged for c-Fos, ChAT, and Syto16 using whole-brain light-sheet microscopy to establish genotype and drug-dependent activation patterns that could be correlated with VU595's efficacy on apneas. The vehicle-treated brain exhibited broad hyperactivity when coupled with the phenotypic prescreen, which was significantly decreased by administration of VU595, particularly in regions known to modulate the activity of respiratory nuclei (i.e. hippocampus and striatum). Further, the extent of apnea rescue in each mouse showed a significant positive correlation with c-Fos expression in non-cholinergic neurons in the striatum, thalamus, dentate gyrus, and within the cholinergic neurons of the brainstem. These results indicate that mice are prone to hyperactivity in brain regions that regulate respiration, which can be normalized through M potentiation.
PubMed: 38659804
DOI: 10.1101/2024.04.15.586099 -
Current Opinion in Pediatrics Jun 2024We highlight novel and emerging therapies in the treatment of childhood-onset movement disorders. We structured this review by therapeutic entity (small molecule drugs,... (Review)
Review
PURPOSE OF REVIEW
We highlight novel and emerging therapies in the treatment of childhood-onset movement disorders. We structured this review by therapeutic entity (small molecule drugs, RNA-targeted therapeutics, gene replacement therapy, and neuromodulation), recognizing that there are two main approaches to treatment: symptomatic (based on phenomenology) and molecular mechanism-based therapy or 'precision medicine' (which is disease-modifying).
RECENT FINDINGS
We highlight reports of new small molecule drugs for Tourette syndrome, Friedreich's ataxia and Rett syndrome. We also discuss developments in gene therapy for aromatic l-amino acid decarboxylase deficiency and hereditary spastic paraplegia, as well as current work exploring optimization of deep brain stimulation and lesioning with focused ultrasound.
SUMMARY
Childhood-onset movement disorders have traditionally been treated symptomatically based on phenomenology, but focus has recently shifted toward targeted molecular mechanism-based therapeutics. The development of precision therapies is driven by increasing capabilities for genetic testing and a better delineation of the underlying disease mechanisms. We highlight novel and exciting approaches to the treatment of genetic childhood-onset movement disorders while also discussing general challenges in therapy development for rare diseases. We provide a framework for molecular mechanism-based treatment approaches, a summary of specific treatments for various movement disorders, and a clinical trial readiness framework.
Topics: Child; Humans; Deep Brain Stimulation; Friedreich Ataxia; Genetic Therapy; Movement Disorders; Precision Medicine; Rett Syndrome; Tourette Syndrome
PubMed: 38655812
DOI: 10.1097/MOP.0000000000001354 -
Advanced Science (Weinheim,... Jun 2024The CRISPR-Cas9 technology has the potential to revolutionize the treatment of various diseases, including Rett syndrome, by enabling the correction of genes or...
The CRISPR-Cas9 technology has the potential to revolutionize the treatment of various diseases, including Rett syndrome, by enabling the correction of genes or mutations in human patient cells. However, several challenges need to be addressed before its widespread clinical application. These challenges include the low delivery efficiencies to target cells, the actual efficiency of the genome-editing process, and the precision with which the CRISPR-Cas system operates. Herein, the study presents a Magnetic Nanoparticle-Assisted Genome Editing (MAGE) platform, which significantly improves the transfection efficiency, biocompatibility, and genome-editing accuracy of CRISPR-Cas9 technology. To demonstrate the feasibility of the developed technology, MAGE is applied to correct the mutated MeCP2 gene in induced pluripotent stem cell-derived neural progenitor cells (iPSC-NPCs) from a Rett syndrome patient. By combining magnetofection and magnetic-activated cell sorting, MAGE achieves higher multi-plasmid delivery (99.3%) and repairing efficiencies (42.95%) with significantly shorter incubation times than conventional transfection agents without size limitations on plasmids. The repaired iPSC-NPCs showed similar characteristics as wild-type neurons when they differentiated into neurons, further validating MAGE and its potential for future clinical applications. In short, the developed nanobio-combined CRISPR-Cas9 technology offers the potential for various clinical applications, particularly in stem cell therapies targeting different genetic diseases.
Topics: Rett Syndrome; CRISPR-Cas Systems; Gene Editing; Humans; Induced Pluripotent Stem Cells; Magnetite Nanoparticles; Methyl-CpG-Binding Protein 2; Genetic Therapy
PubMed: 38647391
DOI: 10.1002/advs.202306432 -
Frontiers in Public Health 2024The main aim of the present study was to examine whether the use of a low-tech tool, called click4all, inserted into cognitive and motor training can increase social... (Observational Study)
Observational Study Randomized Controlled Trial
INTRODUCTION
The main aim of the present study was to examine whether the use of a low-tech tool, called click4all, inserted into cognitive and motor training can increase social interaction of patients with Rett Syndrome (RTT) with classmates in a school setting.
METHODS
Twenty-seven participants with RTT were randomly assigned to two groups: the experimental group received treatment with click4all, and the control group received traditional treatment without click4all. Parameters were measured before treatment (T1), 6 months after treatment (T2), 6 months after the second treatment phase (T3) and at the end of the third treatment phase (T4).
RESULTS
The results demonstrated an increase in levels of social interaction among classmates and patients with RTT in the experimental group, over time, compared to the control group, 95% CI [5.20-15.30]. Classmates also showed a higher level of knowledge related to participants of the experimental group, and this increased over time, 95% CI [24.98-63.52]. The level of knowledge related to the control group was stable over time and lower than the experimental group.
DISCUSSION
This study demonstrated that the use of a low-tech tool can increase social interactions of patients with RTT in a school setting. This is important, as patients with RTT are often restricted in an isolation condition.
Topics: Humans; Rett Syndrome; Female; Social Interaction; Child; Adolescent; Male; Schools
PubMed: 38645452
DOI: 10.3389/fpubh.2024.1353099 -
Epilepsy & Behavior : E&B Jun 2024In 2009, the International Ketogenic Diet Study Group published recommendations for children receiving ketogenic diet (KD) therapy for epilepsy. The document included a...
BACKGROUND
In 2009, the International Ketogenic Diet Study Group published recommendations for children receiving ketogenic diet (KD) therapy for epilepsy. The document included a table listing epilepsy syndromes and conditions in which the KD has been particularly beneficial, hoping that physicians would refer children for the KD sooner.
PURPOSE
To measure the impact of these 2009 recommendations on referral practice, we compared children initiated on the KD at Johns Hopkins Hospital (JHH) 10 years before and after the recommendations.
RESULTS
Overall, children referred to the KD who met indications increased from the pre- to post-recommendation group, 44 % (112/256) to 69 % (175/255) (p < 0.001), with JHH neurologists specifically referring more frequently (10/112, 9 % to 58/175, 33 %) (p < 0.01). Referrals increased for Glut-1 deficiency (0 % to 2.4 %, p = 0.015), Dravet syndrome (0 % to 6.7 %, p < 0.01), Rett syndrome (0.4 % to 3 %, p = 0.018), and formula-fed only status (16 % to 31 %, p < 0.01). The chances of > 50 % seizure reduction for all children referred improved slightly between decades (56 % to 61 %, p = 0.30).
CONCLUSIONS
Following the 2009 recommendations, our study shows there was an increase in referrals for children with indications at our center. Referrals from neurologists at our own institution increased the most. Ketogenic diet efficacy improved slightly over time but did not reach significance.
Topics: Humans; Diet, Ketogenic; Female; Referral and Consultation; Male; Child; Child, Preschool; Epilepsy; Infant; Adolescent; Consensus; Pediatrics
PubMed: 38643663
DOI: 10.1016/j.yebeh.2024.109791 -
Spine Deformity Jul 2024Scoliosis is a common complication of neuromuscular disorders. These patients are frequently recalcitrant to nonoperative treatment. When treated surgically, they have... (Review)
Review
Scoliosis is a common complication of neuromuscular disorders. These patients are frequently recalcitrant to nonoperative treatment. When treated surgically, they have the highest risk of complications of all forms of scoliosis. While recent studies have shown an improvement in the rate of complications, they still remain high ranging from 6.3 to 75% depending upon the underlying etiology and the treatment center (Mohamad et al. in J Pediatr Orthop 27:392-397, 2007; McElroy et al. in Spine, 2012; Toll et al. in J Neurosurg Pediatr 22:207-213, 2018; Cognetti et al. in Neurosurg Focus 43:E10, 2017). For those patients who are able to recover from the perioperative period without major complications, several recent studies have shown decreased long-term mortality and improved health-related quality of life in neuromuscular patients who have undergone spine fusion (Bohtz et al. in J Pediatr Orthop 31:668-673, 2011; Ahonen et al. in Neurology 101:e1787-e1792, 2023; Jain et al. in JBJS 98:1821-1828, 2016). It is critically important to optimize patients preoperatively to minimize the risk of post-operative complications and maximize long-term outcomes. In order to do so, one must familiarize themselves with the common complications and their treatment. The most common complications are pulmonary in nature. With reported rates as high as 23-29%, pre-operative optimization should be employed for these patients to minimize the risk of post-operative complications (Sharma et al. in Eur Spine J 22:1230-1249, 2013; Rumalla et al. in J Neurosurg Spine 25:500-508, 2016). The next most common cause of complications are implant related, with 13-23% of patients experiencing an implant-related complication that may require a second procedure (Toll et al. in J Neurosurg Pediatr 22:207-213, 2018; Sharma et al. in Eur Spine J 22:1230-1249, 2013) Therefore optimization of bone quality prior to surgical intervention is important to help minimize the risk of instrumentation failure. Optimization of muscle tone and spasticity may help to decrease the risk of instrumentation complications, but may also contribute to the progression of scoliosis. While only 3% of patients have neurologic complication, significant equipoise remains regarding whether or not patients should undergo prophylactic detethering procedures to minimize those risks (Sharma et al. in Eur Spine J 22:1230-1249, 2013). Although only 1.8% of complications are classified as cardiac related, they can be among the most devastating (Rumalla et al. in J Neurosurg Spine 25:500-508, 2016). Simply understanding the underlying etiology and the potential risks associated with each condition (i.e., conduction abnormalities in a patient with Rett syndrome or cardiomyopathies patients with muscular dystrophy) can be lifesaving. The following article is a summation of the half day course on neuromuscular scoliosis from the 58th annual SRS annual meeting, summarizing the recommendations from some of the world's experts on medical considerations in surgical treatment of neuromuscular scoliosis.
Topics: Scoliosis; Humans; Neuromuscular Diseases; Spinal Fusion; Postoperative Complications; Preoperative Care; Quality of Life; Societies, Medical
PubMed: 38634998
DOI: 10.1007/s43390-024-00865-4 -
European Journal of Human Genetics :... Apr 2024Copy number variants (CNVs) represent the genetic cause of about 15-20% of neurodevelopmental disorders (NDDs). We identified a ~67 kb de novo intragenic deletion on...
Copy number variants (CNVs) represent the genetic cause of about 15-20% of neurodevelopmental disorders (NDDs). We identified a ~67 kb de novo intragenic deletion on chromosome 2q22.3 in a female individual showing a developmental encephalopathy characterised by epilepsy, severe intellectual disability, speech delay, microcephaly, and thin corpus callosum with facial dysmorphisms. The microdeletion involved exons 5-6 of GTDC1, encoding a putative glycosyltransferase, whose expression is particularly enriched in the nervous system. In a previous study, a balanced de novo translocation encompassing GTDC1 was reported in a male child with global developmental delay and delayed speech and language development. Based on these premises, we explored the transcriptomic profile of our proband to evaluate the functional consequences of the novel GTDC1 de novo intragenic deletion in relation to the observed neurodevelopmental phenotype. RNA-seq on the proband's lymphoblastoid cell line (LCL) showed expression changes of glycine/serine and cytokine/chemokine signalling pathways, which are related to neurodevelopment and epileptogenesis. Subsequent analysis by ELISA (enzyme-linked immunosorbent assay) and HPLC (high-performance liquid chromatography) revealed increased levels of glycine in the proband's LCL and serum compared to matched controls. Given that an increased level of glycine has been observed in the plasma samples of individuals with Rett syndrome, a condition sharing epilepsy, microcephaly, and intellectual disability with our proband, we proposed that the GTDC1 downregulation is implicated in neurodevelopmental impairment by altering glycine metabolism. Furthermore, our findings expanded the phenotypic spectrum of the novel GTDC1-related condition, including microcephaly and epilepsy among relevant clinical features.
PubMed: 38605125
DOI: 10.1038/s41431-024-01603-0 -
Frontiers in Genetics 2024Rett syndrome (RTT, MIM #312750) is a rare genetic disorder that leads to developmental regression and severe disability and is caused by pathogenic variants in the...
Rett syndrome (RTT, MIM #312750) is a rare genetic disorder that leads to developmental regression and severe disability and is caused by pathogenic variants in the gene. The diagnosis of RTT is based on clinical features and, depending on resources and access, on molecular confirmation. There is scarce information on molecular diagnosis from patients in Latin America, mostly due to limited availability and coverage of genomic testing. This pilot study aimed to implement genomic testing and characterize clinical and molecular findings in a group of Chilean patients with a clinical diagnosis of RTT. Twenty-eight patients with suspected RTT underwent characterization of phenotypic manifestations and molecular testing using Clinical Exome Solution CES_V2 by SOPHiA Genetics. Data was analyzed using the commercial bioinformatics platform, SOPHiA DDM. A virtual panel of 34 genes, including and other genes that are in the differential diagnosis of RTT, was used to prioritize initial analyses, followed by evaluation of the complete exome sequence data. Twelve patients (42.8% of participants) had variants in , of which 11 (39.2%) were interpreted as pathogenic/likely pathogenic (P/LP), thus confirming the diagnosis of RTT in them. Eight additional patients (28.5%) harbored ten variants in nine other genes. Four of these variants were interpreted as P/LP (14.2%) ( and ) resulting in alternative neurodevelopmental diagnoses, and six were considered of uncertain significance. No evident candidate variant was found for eight patients. This study allowed to reach a diagnosis in half of the participants. The diagnosis of RTT was confirmed in over a third of them, while others were found to have alternative neurodevelopmental disorders. Further evaluation is needed to identify the cause in those with negative or uncertain results. This information is useful for the patients, families, and clinicians to guide clinical management, even more so since the development of novel therapies for RTT. We also show the feasibility of implementing a step-wide approach to genomic testing in a setting with limited resources.
PubMed: 38566815
DOI: 10.3389/fgene.2024.1278198 -
BioRxiv : the Preprint Server For... Mar 2024A longstanding challenge in gene therapy is expressing a dosage-sensitive gene within a tight therapeutic window. For example, loss of function causes Rett syndrome,...
A longstanding challenge in gene therapy is expressing a dosage-sensitive gene within a tight therapeutic window. For example, loss of function causes Rett syndrome, while its duplication causes duplication syndrome. Viral gene delivery methods generate variable numbers of gene copies in individual cells, creating a need for gene dosage-invariant expression systems. Here, we introduce a compact miRNA-based, incoherent feed-forward loop circuit that achieves precise control of expression in cells and brains, and improves outcomes in an AAV-based mouse model of Rett syndrome gene therapy. Single molecule analysis of endogenous and ectopic mRNA revealed precise, sustained expression across a broad range of gene dosages. Delivered systemically in a brain-targeting AAV capsid, the circuit strongly suppressed Rett behavioral symptoms for over 24 weeks, outperforming an unregulated gene therapy. These results demonstrate that synthetic miRNA-based regulatory circuits can enable precise in vivo expression to improve the safety and efficacy of gene therapy.
PubMed: 38559034
DOI: 10.1101/2024.03.13.584179