Biology subjects

Nalesso, V.

Publications and source records attributed to Nalesso, V..

8 recordsLinked to original sources

bioRxiv2026

Differential efficacy of α5IA in the Dp(16)1Yey mouse model of Down syndrome: implications for translational research

Cognitive impairments significantly impact the daily life of people with Down syndrome (DS). Overinhibition mediated by interneurons in the central nervous system was proposed as a key pathophysiological mechanism. Previous studies demonstrated cognitive rescue in the Ts65Dn mouse model using 5IA, a negative allosteric modulator of the 5 subunit-containing GABAA receptors. Here, we evaluated the effect of this drug in a mouse model carrying a more accurate duplication of the orthologous region to the human chromosome 21, namely the Dp(16)1Yey mouse model. First, we expanded the phenotypic characterization of Dp(16)1Yey mice using translationally more relevant behavioral tests. We confirmed spatial memory deficits in Dp(16)1Yey mice in the Barnes maze, and highlighted robust learning deficits in the pattern dissociation task and impairments in motor coordination. Next, we evaluated the effect of 5IA treatment on cognitive and motor performance. While 5IA treatment improved motor coordination in the Dp(16)1Yey mice, it failed to restore cognitive performance in the Barnes maze or in the pattern dissociation task. These findings could suggest divergent pathophysiological mechanisms between the Dp(16)1Yey and the Ts65Dn models. Potentially, it could explain the limited efficacy of similar pharmacological intervention in clinical trials for DS. Further preclinical studies should prioritize refined behavioral paradigms and probably the use of more complex DS models to enhance the translational potential of candidate therapies.

neuroscience↗

bioRxiv2024

Cognitive and molecular characterization of the Ts66Yah murine model of Down syndrome: deepening on hippocampal changes associated with genotype and aging.

Down syndrome (DS) is the most common condition with intellectual disability and is caused by trisomy of Homo sapiens chromosome 21 (HSA21). The increased dosage of genes on HSA21 is the cause for the initial neurodevelopmental disorder and for further development of cognitive decline, however the molecular mechanisms promoting brain pathology along ageing are still missing. One of the major challenges in the study of DS is the lack of reliable murine model able to accurately replicate genotypic and phenotypic aspects observed in humans along ageing. Preclinical studies in DS were pioneered using the Ts65Dn murine model, which despite its genetic limitations, has been extremely helpful in characterising the progression of brain degeneration. The novel Ts66Yah model represents an evolution of the Ts65Dn, with phenotypes only induced by trisomic HSA21 homologous genes, closer to human DS condition. In this study, we confirmed the behavioural features of Ts66Yah mice with improvement in the detection of spatial memory defects and also a new anxiety-related phenotype. The molecular characterisation of Ts66Yah demonstrated the aberrant regulation of redox balance, proteostasis, stress response, metabolic pathways, programmed cell death and synaptic plasticity. Intriguingly, the genotype-related alterations of those pathways occur early promoting the alteration of brain development and the onset of a condition of premature aging. Overall, data collected in Ts66Yah provide novel and consolidated insights, devoid of genome bias, concerning trisomy-driven processes that contribute to brain pathology in conjunction with aging. This, in turn, aids in bridging the existing gap in comprehending the intricate nature of DS phenotypes.

pathology↗

bioRxiv2023

Interneuron migration defects during corticogenesis contribute to Dyrk1a haploinsufficiency syndrome pathogenesis via actomyosin dynamics deregulations

Interneuron development is a crucial step of brain corticogenesis. When affected it often leads to brain dysfunctions, such as epilepsy, intellectual disabilities and autism spectrum disorder. Such defects are observed in the DYRK1A-haploinsufficiency syndrome, caused by mutations of DYRK1A, and commonly associated to cortical excitatory/inhibitory imbalance. However, how this imbalance is established in this syndrome remains elusive. Here, using mouse models and live imaging, we show that Dyrk1a specifically regulates the development of the cortical GABAergic system. Unlike projection excitatory neurons, we demonstrate that interneuron tangential migration relies on Dyrk1a dosage and kinase activity through a mechanism involving actomyosin cytoskeleton remodeling. Interestingly, we further demonstrate that mice with heterozygous inactivation of Dyrk1a in interneurons show behavioral defects and epileptic activity, recapitulating phenotypes observed in human patients. Altogether, these data highlight the critical role of Dyrk1a in the development of the GABAergic system and the pathophysiology of DYRK1A-haploinsufficiency syndrome.

developmental biology↗

bioRxiv2023

Towards Preclinical Validation of Arbaclofen (R-baclofen) Treatment for 16p11.2 Deletion Syndrome

A microdeletion on human chromosome 16p11.2 is one of the most common copy number variants associated with autism spectrum disorder and other neurodevelopmental disabilities. Arbaclofen, a GABA(B) receptor agonist, is a component of racemic baclofen, which is FDA-approved for treating spasticity, and has been shown to alleviate behavioral phenotypes, including recognition memory deficits, in animal models of 16p11.2 deletion. Given the lack of reproducibility sometimes observed in mouse behavioral studies, we brought together a consortium of four laboratories to study the effects of arbaclofen on behavior in three different mouse lines with deletions in the mouse region syntenic to human 16p11.2 to test the robustness of these findings. Arbaclofen rescued cognitive deficits seen in two 16p11.2 deletion mouse lines in traditional recognition memory paradigms. Using an unsupervised machine-learning approach to analyze behavior, one lab found that arbaclofen also rescued differences in exploratory behavior in the open field in 16p11.2 deletion mice. Arbaclofen was not sedating and had modest off-target behavioral effects at the doses tested. Our studies show that arbaclofen consistently rescues behavioral phenotypes in 16p11.2 deletion mice, providing support for clinical trials of arbaclofen in humans with this deletion. One sentence summaryExperiments across four laboratories found that arbaclofen rescued cognitive deficits in mouse models of 16p11.2 deletion, without sedation or significant off-target behavioral effects.

neuroscience↗

bioRxiv2023

Changes in social behaviour with alterations of MAPK3 and KCTD13/CUL3 pathways in two new outbred rat models for the 16p11.2 syndromes with autism spectrum disorders.

Copy number variations (CNVs) of the human 16p11.2 locus are associated with several developmental/neurocognitive syndromes. Particularly, deletion and duplication of this genetic interval are found in patients with autism spectrum disorders, intellectual disability and other psychiatric traits. The high gene density associated with the region and the strong phenotypic variability of incomplete penetrance, make the study of the 16p11.2 syndromes extremely complex. To systematically study the effect of 16p11.2 CNVs and identify candidate genes and molecular mechanisms involved in the pathophysiology, mouse models were generated previously and showed learning and memory, and to some extent social deficits. To go further in understanding the social deficits caused by 16p11.2 syndromes, we engineered deletion and duplication of the homologous region to the human 16p11.2 genetic interval in two rat outbred strains, Sprague Dawley (SD) and Long Evans (LE). The 16p11.2 rat models displayed convergent defects in social behaviour and only a few cognitive defects. Interestingly major pathways affecting MAPK3 and CUL3 were found altered in the rat 16p11.2 models with additional changes in males compared to females. Altogether, the consequences of the 16p11.2 genetic region dosage on social behaviour are now found in three different species: humans, mice and rats. In addition, the rat models pointed to sexual dimorphism, with lower severity of phenotypes in rat females compared to male mutants. This phenomenon is also observed in humans. We are convinced that the two rat models will be key to further investigating social behaviour and understanding the brain mechanisms and specific brain regions that are key to controlling social behaviour.

animal behavior and cognition↗

bioRxiv2022

A 16p11.2 deletion mouse model displays quantitatively and qualitatively different behaviours in sociability and social novelty over short- and long-term observation.

BackgroundAutism spectrum disorders affect more than one percent of the population, impairing social communication and increasing stereotyped behaviours. A micro-deletion of the 16p11.2 BP4-BP5 chromosomic region has been identified in one percent of patients also displaying intellectual disabilities. In mouse models generated to understand the mechanisms of this deletion, learning and memory deficits were pervasive in most genetic backgrounds, while social communication deficits were only detected in some models. MethodsBased on previous study (Arbogast et al. 2016 PLoS genetics), we itemized the social deficits in the mouse model of 16p11.2 deletion on a hybrid C57BL/6NxC3H.Pde6b+ genetic background. We examined whether behavioural deficits were visible over long-term observation periods, to parallel everyday-life assessment of patients. We recorded the individual and social behaviours of 16p11.2 Del/+ mice and their wild-type littermates from both sexes in long-term (over two and three consecutive nights) social interactions of familiar mixed-genotype quartets of males and of females, and of same-genotype unfamiliar female pairs. ResultsWe observed that Del/+ mice of both sexes increased significantly their locomotor activity compared to wild-type littermates over long-term monitoring. In the social domain, Del/+ mice of both sexes displayed widespread deficits over long-term monitoring, even more so in males than in females in quartets of familiar individuals. In pairs, significant perturbations of the organisation of the social communication and behaviours appeared in Del/+ females. DiscussionAltogether, this suggests that, over long recording periods, the phenotype of the 16p11.2 Del/+ mice was differently affected in the locomotor activity and the social domains and between the two sexes. These findings confirm the importance of testing models in long-term conditions to provide a comprehensive view of their phenotype that will refine the study of cellular and molecular mechanisms and complement pre-clinical targeted therapeutic trials.

animal behavior and cognition↗

bioRxiv2022

Ts66Yah, a refined Ts65Dn DS mouse model, unravels genetic interaction between regions homologous to Human chromosome 21 and the Scaf8-Pde10a genetic interval.

Down syndrome is caused by trisomy of human chromosome 21 (Hsa21). The understanding of phenotype-genotype relationships, the identification of driver genes and various proof-of-concepts for therapeutics have benefited from mouse models. The premier model, named Ts(1716)65Dn/J (Ts65Dn), displayed phenotypes related to the human DS features. It carries an additional minichromosome with the Mir155 to Zbtb21 region of mouse chromosome 16 (Mmu16), homologous to Hsa21, encompassing around 90 genes, fused to the centromeric part of mouse chromosome 17 (Mmu17) fromPisd-ps2/Scaf8 to Pde10a, containing 46 genes, not related to Hsa21. Here, we report the investigation of a new model, Ts66Yah, generated by CrispR/Cas9 without the genomic region unrelated to Hsa21 on the minichromosome. As expected, Ts66Yah replicated DS cognitive features. However, certain phenotypes related to increased activity, spatial learning and molecular signatures, were changed suggesting genetic interactions between the Mir155-Zbtb21 and the Scaf8-Pde10a interval. Thus, Ts66Yah mice have a stronger construct and face validity for mimicking consequences of DS genetic overdosage. Furthermore, this report is the first to demonstrate genetic interactions between triplicated regions homologous to Hsa21 and others unrelated to Hsa21.

genetics↗

bioRxiv2020

Targeting the RHOA pathway improves learning and memory in Kctd13 and 16p11.2 deletion mouse models.

Gene copy number variants (CNV) have an important role in the appearance of neurodevelopmental disorders. Particularly, the deletion of the 16p11.2 locus is associated with autism spectrum disorder, intellectual disability, and several other features. Earlier studies highlighted the implication of Kctd13 genetic imbalance in the 16p11.2 deletion through the regulation of the RHOA pathway. Here, we target the pathway and rescue the cognitive phenotypes of the 16p11.2 deletion mouse models. We used a chronic administration of fasudil (HA1077), an inhibitor of the Rho-associated protein kinase (ROCK), in mouse models carrying a heterozygous inactivation of Kctd13, or the deletion of the entire 16p11.2 BP4-BP5 region. We focused our attention on the most robust cognitive phenotypes seen in the 16p11.2 models and we showed that a chronic fasudil treatment can restore object recognition memory in both mouse models but does not change other behavioural traits. These findings confirm KCTD13 as one target gene causing cognitive deficits in 16p11.2 deletion patients, and the pertinence of the RHOA pathway as a therapeutic path and reinforce the contribution of other gene(s) involved in cognitive defects found in the 16p11.2 CNV models. HIGHLIGHTS- Kctd13 haploinsufficiency recapitulates most of the behaviour phenotypes found in the 16p11.2 Del/+ models - Fasudil treatment restores Kctd13 and 16p11.2 Del/+ mutant phenotypes in novel location and novel object recognition memory tests - Fasudil treatment restores the RhoA pathway in Kctd13+/- and 16p11.2 Del/+ models

animal behavior and cognition↗