Biology subjects

Fernandez-Castillo, N.

Publications and source records attributed to Fernandez-Castillo, N..

10 recordsLinked to original sources

bioRxiv2026

Sex-specific vulnerability to cannabinoid addiction-like behavior and associated miRNA signatures in a WIN 55,212-2 self-administration mouse model

Cannabis is one of the most widely used psychoactive substances worldwide, and cannabis use disorder (CUD) is increasingly recognized as a major public health concern. Clinical evidence indicates that women may be particularly vulnerable to developing addiction, exhibiting a faster transition from initial drug use to loss of control and increased relapse vulnerability. However, females remain underrepresented in both preclinical and clinical research, limiting our understanding of the neurobiological mechanisms underlying this susceptibility. Here, we investigated sex differences in behavioral and epigenetic susceptibility to cannabinoid addiction using a mouse operant self-administration model with the synthetic cannabinoid agonist WIN 55,212-2. Female mice displayed increased addiction-like behavior, characterized by greater persistence of responding during drug-free periods and enhanced compulsive-like drug seeking compared to males. miRNA profiling in the medial prefrontal cortex (mPFC) identified a female-specific epigenetic signature associated with the addiction-like phenotype, including downregulation of mmu-miR-669j, mmu-miR-7036b-5p, mmu-miR-878-3p, and mmu-miR-7017-3p, together with upregulation of mmu-miR-3092-5p in addicted females. Functional enrichment analyses of predicted target genes revealed pathways related to synaptic organization, axon guidance, neurotransmission, and structural plasticity. Together, these findings demonstrate sex-dependent differences in vulnerability to cannabinoid addiction-like behavior and identify a specific miRNA signature in the mPFC associated with this phenotype, highlighting potential targets for the development of sex-specific therapeutic strategies.

neuroscience↗

bioRxiv2024

rbfox1 loss of function in zebrafish leads to dysregulation in bdnf/trkb2 and pac1a expression resulting in HPI axis hyperactivation, altered stress response and allostatic overload

Mutations in the RBFOX1 gene are associated with psychiatric disorders but how RBFOX1 influences psychiatric disorder vulnerability remains unclear. Recent studies showed that RBFOX proteins mediate the alternative splicing of PAC1, a critical HPA axis activator. Further, RBFOX1 dysfunction is linked to dysregulation of BDNF/TRKB, a pathway promoting neuroplasticity, neuronal survival, and stress resilience. Hence, RBFOX1 dysfunction may increase psychiatric disorder vulnerability via HPA axis dysregulation, leading to disrupted development and allostatic overload. To test this hypothesis, we generated a zebrafish rbfox1 loss of function (LoF) line and examined behavioural and molecular effects during development. We found that rbfox1 LoF mutants exhibited hyperactivity, impulsivity and heightened arousal, alongside alterations in proliferation - traits associated with neurodevelopmental and stress-related disorders. In adults, loss of rbfox1 function led to decreased fertility and survival, consistent with allostatic overload. At the molecular level, at larval stages rbfox1 mutants showed increased cortisol levels and disrupted expression of key stress-related genes (bdnf, trkb2, pac1a-hop, crhb, nr3c2). Pharmacological intervention targeting TRKB restored crhb and nr3c2 gene expression and hyperactive and hyperarousal behaviours. In adults, dysregulation of crhb, nr3c2 and bdnf/trkb2 genes was only seen following acute stress exposure. Our findings reveal a fundamental role for RBFOX1 in integrating stress responses through its regulation of BDNF/TRKB and neuroendocrine signalling. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/616976v5_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@17e3bbcorg.highwire.dtl.DTLVardef@83f0eeorg.highwire.dtl.DTLVardef@3e9985org.highwire.dtl.DTLVardef@1d116ff_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗

bioRxiv2023

Pleiotropic contribution of rbfox1 to psychiatric and neurodevelopmental phenotypes in a zebrafish model

RBFOX1 is a highly pleiotropic gene that contributes to several psychiatric and neurodevelopmental disorders. Both rare and common variants in RBFOX1 have been associated with several psychiatric conditions, but the mechanisms underlying the pleiotropic effects of RBFOX1 are not yet understood. Here we found that, in zebrafish, rbfox1 is expressed in spinal cord, mid- and hindbrain during developmental stages. In adults, expression is restricted to specific areas of the brain, including telencephalic and diencephalic regions with an important role in receiving and processing sensory information and in directing behaviour. To investigate the effect of rbfox1 deficiency on behaviour, we used rbfox1sa15940, a rbfox1 loss-of-function line. We found that rbfox1sa15940 mutants present hyperactivity, thigmotaxis, decreased freezing behaviour and altered social behaviour. We repeated these behavioural tests in a second rbfox1 loss-of-function line with a different genetic background, rbfox1del19, and found that rbfox1 deficiency affects behaviour similarly in this line, although there were some differences. rbfox1del19 mutants present similar thigmotaxis, but stronger alterations in social behaviour and lower levels of hyperactivity than rbfox1sa15940 fish. Taken together, these results suggest that rbfox1 deficiency leads to multiple behavioural changes in zebrafish that might be modulated by environmental, epigenetic and genetic background effects, and that resemble phenotypic alterations present in Rbfox1-deficient mice and in patients with different psychiatric conditions. Our study thus highlights the evolutionary conservation of rbfox1 function in behaviour and paves the way to further investigate the mechanisms underlying rbfox1 pleiotropy on the onset of neurodevelopmental and psychiatric disorders.

genetics↗

bioRxiv2021

Deficiency of the ywhaz gene, involved in neurodevelopmental disorders, alters brain activity and behaviour in zebrafish

Genetic variants in YWHAZ contribute to psychiatric disorders such as autism spectrum disorder and schizophrenia, and have been related to an impaired neurodevelopment in humans and mice. Here, we used zebrafish to further understand the mechanisms by which YWHAZ contributes to neurodevelopmental disorders. We observed that ywhaz expression was panneuronal during developmental stages and restricted to Purkinje cells in the adult cerebellum, cells that are described to be reduced in number in autistic patients. We then performed whole-brain imaging in wild-type and ywhaz CRISPR/Cas9 knockout (KO) larvae and found altered neuronal activity and connectivity in the hindbrain. Adult ywhaz KO fish display decreased levels of monoamines in the hindbrain and freeze when exposed to novel stimuli, a phenotype that can be reversed with drugs that target monoamine neurotransmission. These findings suggest an important role for ywhaz in establishing neuronal connectivity during development and modulating both neurotransmission and behaviour in adults.

neuroscience↗

bioRxiv2020

Loss of Kinesin-8 improves the robustness of the acentrosomal spindle

Chromosome segregation in female meiosis is inherently error-prone, among other reasons, because the acentrosomal spindle assembles and segregates chromosomes without the major microtubule-organizing centres in eukaryotes, the centrosomes, which causes high rate of aneuploidy. The molecular basis underlying formation of acentrosomal spindles is not as well-understood as that of centrosomal spindles and, consequently, strategies to improve spindle robustness are difficult to address. Recently, we noticed during fission yeast meiosis the formation of unexpected microtubules arrays, independent of the spindle pole bodies (yeast centrosome equivalent), with ability to segregate chromosomes. Here, we establish such microtubules formation as bonafide self-assembled spindles that depend on the canonical microtubule crosslinker Ase1/PRC1, share similar structural polarity and harbour the microtubule polymerase Alp14/XMAP215, while being independent of conventional {gamma}-tubulin-mediated nucleation mechanisms. Remarkably, acentrosomal spindle robustness was reinforced by deletion of the Klp6/Kinesin-8, which, consequently, led to a reduced meiotic aneuploidy rate. Our results enlighten the molecular basis of acentrosomal meiosis, a crucial event in understanding gametogenesis.

cell biology↗

bioRxiv2020

Reduced cue-induced reinstatement of cocaine seeking behavior in Plcb1+/- mice

Background and PurposeCocaine addiction causes serious health problems and no effective treatment is available yet. We previously identified a genetic risk variant for cocaine addiction in the PLCB1 gene and found this gene upregulated in postmortem brains of cocaine abusers and in human dopaminergic neuron-like cells after an acute cocaine exposure. Here, we functionally tested the contribution of PLCB1 gene to cocaine addictive properties in mice. Experimental approachWe used heterozygous Plcb1 knockout mice (Plcb1+/-) and characterized their behavioral phenotype. Subsequently, mice were trained for operant conditioning and self-administered cocaine for 10 days. Plcb1+/- mice were assessed for cocaine motivation, followed by 26 days of extinction and finally evaluated for cue-induced reinstatement of cocaine seeking. Gene expression alterations after reinstatement were assessed in medial prefrontal cortex (mPFC) and hippocampus (HPC) by RNAseq. Key ResultsPlcb1+/- mice showed normal behavior, although they had increased anxiety and impaired short-term memory. Importantly, after cocaine self-administration and extinction, we found a reduction in the cue-induced reinstatement of cocaine-seeking behavior in Plcb1+/- mice. After reinstatement, we identified transcriptomic alterations in the medial prefrontal cortex of Plcb1+/- mice, mostly related to pathways relevant to addiction like the dopaminergic synapse and long-term potentiation. Conclusions and ImplicationsTo conclude, we found that heterozygous deletion of the Plcb1 gene decreases cue-induced reinstatement of cocaine seeking, pointing at PLCB1 as a possible therapeutic target for preventing relapse and treating cocaine addiction.

animal behavior and cognition↗

bioRxiv2019

Cross-disorder genetic analyses implicate dopaminergic signaling as a biological link between Attention-Deficit/Hyperactivity Disorder and obesity measures

Attention-Deficit/Hyperactivity Disorder (ADHD) and obesity are frequently comorbid, genetically correlated, and share brain substrates. The biological mechanisms driving this association are unclear, but candidate systems, like dopaminergic neurotransmission and circadian rhythm, have been suggested. Our aim was to identify the biological mechanisms underpinning the genetic link between ADHD and obesity measures and investigate associations of overlapping genes with brain volumes. We tested the association of dopaminergic and circadian rhythm gene sets with ADHD, body mass index (BMI), and obesity (using GWAS data of N=53,293, N=681,275, and N=98,697, respectively). We then conducted genome-wide ADHD-BMI and ADHD-obesity gene-based meta-analyses, followed by pathway enrichment analyses. Finally, we tested the association of ADHD-BMI overlapping genes with brain volumes (primary GWAS data N=10,720-10,928; replication data N=9,428). The dopaminergic gene set was associated with both ADHD (P=5.81x10-3) and BMI (P=1.63x10-5), the circadian rhythm was associated with BMI (P=1.28x10-3). The genome-wide approach also implicated the dopaminergic system, as the Dopamine-DARPP32 Feedback in cAMP Signaling pathway was enriched in both ADHD-BMI and ADHD-obesity results. The ADHD-BMI overlapping genes were associated with putamen volume (P=7.7x10-3; replication data P=3.9x10-2) - a brain region with volumetric reductions in ADHD and BMI and linked to inhibitory control. Our findings suggest that dopaminergic neurotransmission, partially through DARPP-32-dependent signaling and involving the putamen, is a key player underlying the genetic overlap between ADHD and obesity measures. Uncovering shared etiological factors underlying the frequently observed ADHD-obesity comorbidity may have important implications in terms of prevention and/or efficient treatment of these conditions.

genetics↗

bioRxiv2018

Truncating Variant Burden in High Functioning Autism and Pleiotropic Effects of LRP1 Across Psychiatric Phenotypes

Previous research has implicated de novo (DN) and inherited truncating mutations in autism spectrum disorder (ASD). We aim to investigate whether the load of inherited truncating mutations contribute similarly to high functioning autism (HFA), and to characterise genes harbouring DN variants in HFA.\n\nWe performed whole-exome sequencing (WES) in 20 HFA families (average IQ = 100). No difference was observed in the number of transmitted versus non-transmitted truncating alleles to HFA (117 vs 130, P = 0.32). Transmitted truncating and DN variants in HFA were not enriched in GO or KEGG categories, nor autism-related gene sets. However, in a HFA patient we identified a DN variant in a canonical splice site of LRP1, a post-synaptic density gene that is a target for the FMRP. This DN leads to in-frame skipping of exon-29, removing 2 of 6 blades of the {beta}-propeller domain-4 of LRP1, with putative functional consequences. Results using large datasets implicate LRP1 across psychiatric diseases: i) DN are associated with ASD (P = 0.039) and schizophrenia (P = 0.008) from combined sequencing projects; ii) Common variants using Psychiatric Genomics Consortium GWAS datasets show gene-based association in schizophrenia (P = 6.6E-07) and across six psychiatric diseases (meta-analysis P = 8.1E-05); and iii) burden of ultra-rare pathogenic variants is higher in ASD (P = 1.2E-05), using WES from 6,135 schizophrenia patients, 1,778 ASD patients and 6,245 controls. Previous and current studies suggest an impact of truncating mutations restricted to severe ASD phenotypes associated with intellectual disability. We provide evidence for pleiotropic effects of common and rare variants in the LRP1 gene across psychiatric phenotypes.

genomics↗

bioRxiv2018

Exploring Genetic Variation That Influences Brain Methylation In Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder caused by an interplay of genetic and environmental factors. Epigenetics is crucial to lasting changes in gene expression in the brain. Recent studies suggest a role for DNA methylation in ADHD. We explored the contribution to ADHD of allele-specific methylation (ASM), an epigenetic mechanism that involves SNPs correlating with differential levels of DNA methylation at CpG sites. We selected 3,896 tagSNPs reported to influence methylation in human brain regions and performed a case-control association study using the summary statistics from the largest GWAS meta-analysis of ADHD, comprising 20,183 cases and 35,191 controls. We identified associations with eight tagSNPs that were significant at a 5% False Discovery Rate (FDR). These SNPs correlated with methylation of CpG sites lying in the promoter regions of six genes. Since methylation may affect gene expression, we inspected these ASM SNPs together with 52 ASM SNPs in high LD with them for eQTLs in brain tissues and observed that the expression of three of those genes was affected by them. ADHD risk alleles correlated with increased expression (and decreased methylation) of ARTN and PIDD1 and with a decreased expression (and increased methylation) of C2orf82. Furthermore, these three genes were predicted to have altered expression in ADHD, and genetic variants in C2orf82 correlated with brain volumes. In summary, we followed a systematic approach to identify risk variants for ADHD that correlated with differential cis-methylation, identifying three novel genes contributing to the disorder.

genetics↗

bioRxiv2018

Genome-wide association meta-analysis of cocaine dependence: shared genetics with comorbid conditions

Cocaine dependence is a complex psychiatric disorder that is highly comorbid with other psychiatric traits. Twin and adoption studies suggest that genetic variants contribute substantially to cocaine dependence susceptibility, which has an estimated heritability of 65-79%. Here we performed a meta-analysis of genome-wide association studies of cocaine dependence using four datasets from the dbGaP repository (2,085 cases and 4,293 controls, all of them selected by their European ancestry). Although no genome-wide significant hits were found in the SNP-based analysis, the gene-based analysis identified HIST1H2BD as associated with cocaine-dependence (10% FDR). This gene is located in a region on chromosome 6 enriched in histone-related genes, previously associated with schizophrenia (SCZ). Furthermore, we performed LD Score regression analysis with comorbid conditions and found significant genetic correlations between cocaine dependence and SCZ, ADHD, major depressive disorder (MDD) and risk taking. We also found, through polygenic risk score analysis, that all tested phenotypes can significantly predict cocaine dependence status: SCZ (R2=2.28%; P=1.21e-26), ADHD (R2=1.39%; P=4.5e-17), risk taking (R2=0.60%; P=2.7e-08), MDD (R2=1.21%; P=4.35e-15), childrens aggressiveness (R2=0.3%; P=8.8e-05) and antisocial behavior (R2=1.33%; P=2.2e-16). To our knowledge, this is the largest reported cocaine dependence GWAS meta-analysis in European-ancestry individuals. We identified suggestive associations in regions that may be related to cocaine dependence and found evidence for shared genetic risk factors between cocaine dependence and several comorbid psychiatric traits. However, the sample size is limited and further studies are needed to confirm these results.

genetics↗