Biology subjects

Canales, C. P.

Publications and source records attributed to Canales, C. P..

9 recordsLinked to original sources

bioRxiv2026

Precocious maturation and Purkinje cell dysfunction in the mouse Chd8 haploinsufficient cerebellum

The cerebellum plays an emerging, but understudied, role in neurodevelopmental disorders (NDDs). Mutations in CHD8 cause a monogenic NDD (CHD8-NDD) characterized by autism and other manifestations, and prior work in Chd8 mutant mice reported cerebellar abnormalities, raising the possibility of cerebellar contribution to CHD8-NDD. To comprehensively characterize the impact of Chd8 haploinsufficiency on cerebellar development and function, we profiled the postnatal day 12 (P12) cerebellum of germline Chd8+/- mice using transcriptomic, morphological, and electrophysiological approaches. Gross cerebellar morphology was unaffected, but single-nucleus RNA sequencing revealed transcriptomic signatures of pathophysiology across cell types, including accelerated maturation of molecular layer interneurons and granule cells, and altered myelination state of oligodendrocytes. Purkinje cells (PCs) showed the strongest transcriptomic burden of any cell type and, consistent with this, exhibited altered morphology and electrophysiological properties. Bulk RNA sequencing confirmed that transcriptomic pathology persists into adulthood, indicating lasting impacts on both neuronal and glial gene expression. Together, these results capture cell-type-specific cerebellar perturbations associated with Chd8 haploinsufficiency and support the cerebellum as a relevant site of pathology in CHD8-NDD.

neuroscience↗

bioRxiv2025

Molecular interactions of Chd8 in mouse brain highlights a role in chromatin-associated RNA processing

The chromatin remodeler CHD8 is a model risk gene for neurodevelopmental disorders (NDDs). While CHD8 has nucleosome remodeling capacity, evidence suggests it participates in processes beyond chromatin regulation, raising questions about function in the brain and role in NDDs. We defined CHD8 interactions using a comprehensive multimodal omics approach. Immunoprecipitation followed by mass spectrometry (IP-MS) identified a complex interaction network enriched for chromatin remodeling, RNA processing, and cytoskeletal proteins in neonatal mouse forebrain. We implemented CHD8-TurboID in HEK293T cells, validating IP-MS signatures and further identifying a role in mitosis. In addition to DNA, Chd8 complexed with RNA in mouse forebrain, with affinity for genes associated with RNA splicing and nervous system development and overlap between Chd8-bound mRNA and promoters. Finally, Chd8 interaction affinity with RNA splicing factors was reduced in Chd8 haploinsufficient mice. These findings expand understanding of CHD8 function and identify a dosage-sensitive NDD-relevant role in chromatin-associated RNA processing.

molecular biology↗

bioRxiv2025

Persistent cortical excitatory neuron dysregulation in adult Chd8 haploinsufficient mice.

CHD8 mutations cause autism spectrum disorder, cognitive deficits, and macrocephaly. Chd8+/- mouse models exhibit macrocephaly and transcriptional pathology, with inconsistent findings regarding neurogenesis, neuron function, and behavior. Via stereology and single nucleus transcriptomics (snRNA-seq), we found increased Chd8+/- cortical volume was not explained by increase in neuron number. Differential expression (DE) was present across cortical cell types, with excitatory neurons exhibiting high DE burden and shared and subclass-specific DE signatures. Bulk RNA-seq DE of constitutive Chd8+/- and conditional Camk2a-Cre Chd8+/-mice identified shared transcriptional pathology. DE in synaptosomal versus nuclear mRNA identified overlapping DEGs, but also significant differences and exaggerated synaptosomal changes. Building on DE findings implicating glutamatergic neurons, we found Chd8+/-mice exhibited altered excitatory neuron spine density and dynamics, decreased GCaMP activity correlation, and sleep perturbation. Thus, Chd8 haploinsufficiency causes lasting excitatory neuron dysfunction, perturbs RNA regulation beyond transcription, and impacts neuronal properties, cortical microcircuits, and behavior.

genomics↗

bioRxiv2024

Complimentary vertebrate Wac models exhibit phenotypes relevant to DeSanto-Shinawi Syndrome

Monogenic syndromes are associated with neurodevelopmental changes that result in cognitive impairments and neurobehavioral phenotypes including autism and seizures. Limited studies and resources are available to make meaningful headway into the underlying molecular mechanisms that result in these symptoms. One such example is DeSanto-Shinawi Syndrome (DESSH), a rare disorder caused by pathogenic variants in the WAC gene. Individuals with DESSH syndrome exhibit a recognizable craniofacial gestalt, developmental delay/intellectual disability, neurobehavioral symptoms that include autism, ADHD, behavioral difficulties and seizures. However, no thorough studies from a vertebrate model exist to understand how these changes occur. To overcome this, we developed both murine and zebrafish Wac/wac deletion mutants and studied whether their phenotypes recapitulate those described in individuals with DESSH syndrome. We first show that the two Wac models exhibit craniofacial and behavioral changes, reminiscent of abnormalities found in DESSH syndrome. In addition, each model revealed impacts to GABAergic neurons and further studies showed that the mouse mutants are susceptible to seizures, changes in brain volumes that are different between sexes and relevant behaviors. Finally, we uncovered transcriptional impacts of Wac loss of function in mice that will pave the way for future molecular studies into DESSH. These studies present two new animals that begin to uncover some biological underpinnings of DESSH syndrome and elucidate the biology of Wac.

neuroscience↗

bioRxiv2023

Hyperexcitability and translational phenotypes in a preclinical model of SYNGAP1 mutations

SYNGAP1 is a critical gene for neuronal development, synaptic structure, and function. Although rare, the disruption of SYNGAP1 directly causes a genetically identifiable neurodevelopmental disorder (NDD) called SYNGAP1-related intellectual disability. Without functional SynGAP1 protein, patients present with intellectual disability, motor impairments, and epilepsy. Previous work using mouse models with a variety of germline and conditional mutations has helped delineate SynGAP1s critical roles in neuronal structure and function, as well as key biochemical signaling pathways essential to synapse integrity. Homozygous loss of SYNGAP1 is embryonically lethal. Heterozygous mutations of SynGAP1 result in a broad range of phenotypes including increased locomotor activity, impaired working spatial memory, impaired cued fear memory, and increased stereotypic behavior. Our in vivo functional data, using the original germline mutation mouse line from the Huganir laboratory, corroborated robust hyperactivity and learning and memory deficits. Here, we describe impairments in the translational biomarker domain of sleep, characterized using neurophysiological data collected with wireless telemetric electroencephalography (EEG). We discovered Syngap1+/- mice exhibited elevated spike trains in both number and duration, in addition to elevated power, most notably in the delta power band. Primary neurons from Syngap1+/- mice displayed increased network firing activity, greater spikes per burst, and shorter inter-burst intervals between peaks using high density micro-electrode arrays (HD-MEA). This work is translational, innovative, and highly significant as it outlines functional impairments in Syngap1 mutant mice. Simultaneously, the work utilized untethered, wireless neurophysiology that can discover potential biomarkers of Syngap1R-ID, for clinical trials, as it has done with other NDDs. Our work is substantial forward progress toward translational work for SynGAP1R-ID as it bridges in-vitro electrophysiological neuronal activity and function with in vivo neurophysiological brain activity and function. These data elucidate multiple quantitative, translational biomarkers in vivo and in vitro for the development of treatments for SYNGAP1-related intellectual disability.

neuroscience↗

bioRxiv2021

Increased cortical volume without increased neuron number in heterozygous Chd8 mutant mouse cortex

De novo mutations in the chromatin-remodeling factor CHD8 (Chromodomain-Helicase DNA-binding protein 8) have emerged as a key genetic risk factor for Autism Spectrum Disorder (ASD) and, more generally, neurodevelopmental disorders. Individuals with heterozygous mutations in CHD8 typically present hallmarks of ASD with comorbid cognitive disability and macrocephaly. Knockdown or haploinsufficiency of Chd8 in animal models has recapitulated phenotypes observed in patients, including increased head circumference and brain size. Here, we aimed to determine whether increased neuron numbers or soma size drives increased cortical volume. We performed design-based stereological analyses of cortical structure in adult male and female heterozygous Chd8 mice and wild-type littermate controls. Chd8 haploinsufficient male mice displayed a ~8-12% increase in cortical volume, no differences in cortical neuron number and comparable neuronal soma size. Our study reproduced previous reports of increased brain size associated with CHD8 mutation in humans and mice and are consistent with reported sex-specific impacts of Chd8 mutations in mice and increased burden of CHD8 mutations in human males with ASD. These findings suggest that the nature of the cortical enlargement due to Chd8 haploinsufficiency is complex and appears to be due to a factor other than an increased neuron number or soma size. Lay SummaryWe measured the size and neuron number in the neocortex in mice with heterozygous Chd8 mutation, a model relevant to Autism Spectrum Disorder. We found an increased cortical volume in male mutants, which was not accompanied by increased neuron number or soma size. Our results indicate that the enlarged brain in Chd8 mutant mice is complex, more evident here in males, and is due to factors other than increased neuron number.

neuroscience↗

bioRxiv2020

A temporal map of maternal immune activation-induced changes reveals a shift in neurodevelopmental timing and perturbed cortical development in mice.

BackgroundEnvironmental insults that activate the maternal immune system are potent primers of developmental neuropathology and maternal immune activation (MIA) has emerged as a risk factor for neurodevelopmental and psychiatric disorders. Animal models of MIA provide an opportunity to identify molecular pathways that initiate disease processes and lead to neuropathology and behavioral deficits in offspring. MIA-induced behaviors are accompanied by anatomical and neurochemical alterations in adult offspring that parallel those seen in affected human populations. MethodsWe performed transcriptional profiling and neuroanatomical characterization in a time course across mouse embryonic cortical development, following MIA via single injection of the viral mimic polyinosinic:polycytidylic acid (polyI:C) at E12.5. Transcriptional changes identified in the cortex of MIA offspring at E17.5 were validated and mapped to cortical neuroanatomy and cell types via protein analysis and immunohistochemistry. ResultsMIA induced strong transcriptomic signatures, including induction of genes associated with hypoxia, immune signaling, and angiogenesis. The acute response identified 6h after the MIA insult was followed by changes in proliferation, neuronal and glial differentiation, and cortical lamination that emerged at E14.5 and peaked at E17.5. Decreased numbers of proliferative cell types in germinal zones and alterations in neuronal and glial cell types across cortical lamina were identified in the MIA-exposed cortex. ConclusionsMIA-induced transcriptomic signatures in fetal offspring overlap significantly with perturbations identified in neurodevelopmental disorders (NDDs), and provide novel insights into alterations in molecular and developmental timing processes linking MIA and neuropathology, potentially revealing new targets for development of novel approaches for earlier diagnosis and treatment of these disorders.

neuroscience↗

bioRxiv2020

CRL5-dependent regulation of Arl4c and Arf6 controls hippocampal morphogenesis.

The small GTPase Arl4c participates in the regulation of cell migration, cytoskeletal rearrangements, and vesicular trafficking in epithelial cells. The Arl4c signaling cascade starts by the recruitment of the Arf-GEF cytohesins to the plasma membrane, which in turn engage the small GTPase Arf6. In the nervous system, Arf6 regulates dendrite outgrowth in vitro and neuronal migration in the developing cortex. However, the role of Arl4c-cytohesin-Arf6 signaling during brain development and particularly during hippocampal development remain elusive. Here, we report that the E3 ubiquitin ligase Cullin 5/Rbx2 (CRL5) controls the stability of Arl4c and its signaling effectors to regulate hippocampal morphogenesis. Rbx2 knock out causes hippocampal pyramidal neuron mislocalization and formation of multiple apical dendrites. The same phenotypes were observed when Cullin 5 was knocked down in pyramidal neurons by in utero electroporation. We used quantitative mass spectrometry to show that Arl4c, Cytohesin-1/3, and Arf6 accumulate in the telencephalon when Rbx2 is absent. Arl4c expression is post-transcriptionally regulated, with a peak in expression at early postnatal stages, and is localized at the plasma membrane and on intracellular vesicles in hippocampal pyramidal neurons. Furthermore, we show that depletion of Arl4c rescues the phenotypes caused by Cullin 5 knock down in the hippocampus, whereas depletion of Arf6 exacerbates over-migration. Finally, we show that Arl4c and Arf6 are necessary for the dendritic outgrowth of pyramidal neurons to the most superficial strata of the hippocampus. Overall, we identified CRL5 as a key regulator of hippocampal development and uncovered Arl4c and Arf6 as novel CRL5-regulated signaling effectors that control pyramidal neuron migration and dendritogenesis.

developmental biology↗

bioRxiv2019

Deletion of a non-canonical promoter regulatory element causes loss of Scn1a expression and epileptic phenotypes in mice

Genes with multiple co-active promoters appear common in brain, yet little is known about functional requirements for these potentially redundant genomic regulatory elements. SCN1A, which encodes the NaV1.1 sodium channel alpha subunit, is one such gene with two co-active promoters. Mutations in SCN1A are associated with epilepsy, including Dravet Syndrome (DS). The majority of DS patients harbor coding mutations causing SCN1A haploinsufficiency, however putative causal non-coding promoter mutations have been identified. To determine the functional role of one of these potentially redundant Scn1a promoters, we focused on the non-coding Scn1a 1b regulatory region, previously described as a non-canonical alternative transcriptional start site. Mice harboring a deletion of the extended evolutionarily-conserved 1b non-coding interval exhibited surprisingly severe reductions of Scn1a and NaV1.1 expression in brain with accompanying electroencephalographic seizures and behavioral deficits. This work identified the 1b region as a critical disease-relevant regulatory element and provides evidence that non-canonical and seemingly redundant promoters can have essential function.

neuroscience↗