Biology subjects

Montcouquiol, M.

Publications and source records attributed to Montcouquiol, M..

3 recordsLinked to original sources

bioRxiv2021

Vangl2, a core component of the WNT/PCP pathway, regulates adult hippocampal neurogenesis and age-related decline in cognitive flexibility

Decline in episodic memory is one of the hallmarks of aging and represents one of the most important health problems facing western societies. A key structure in episodic memory is the hippocampal formation and the dentate gyrus in particular, as the continuous production of new dentate granule neurons in this brain region was found to play a crucial role in memory and in age-related decline in memory. As such, understanding the molecular processes that regulate the relationship between adult neurogenesis and aging of memory function holds great therapeutic potential. Recently, we found that Vang-gogh like 2 (Vangl2), a core component of the planar cell polarity signaling pathway, is enriched in the dentate gyrus of adult mice. In this context, we sought to evaluate the involvement of this effector of the Wnt/PCP pathway in both adult neurogenesis and memory abilities in adult and middle-aged mice. Using a heterozygous mouse model carrying a dominant negative mutation in Vangl2 gene, we show that alteration in Vangl2 expression decreases the survival of adult-born granule cells and advances the onset of decrease in cognitive flexibility. Inability of mutant mice to erase old irrelevant information to the benefit of new relevant ones highlights a key role of Vangl2 in interference-based forgetting. Taken together, our findings show for the first that Vangl2 activity may constitute an interesting target to prevent age-related decline in hippocampal plasticity and memory.

neuroscience↗

bioRxiv2020

Scribble controls social behaviors through the regulation of the ERK/Mnk1 pathway

Social behavior is a basic domain affected in several neurodevelopmental disorders. Indeed, deficits in social interest, interactions and recognition represent core symptoms of Autism Spectrum Disorder but are also found associated with a heterogeneous set of neuropsychiatric and rare disorders. The SCRIB gene that codes for the polarity protein SCRIBBLE has been identified as a risk gene for spina bifida, the most common type of open neural tube defect, found at high frequencies in autistic patients, as other congenital anomalies, while the deletions/mutations of the 8q24.3 region encompassing SCRIB genes is associated with multisyndromic and rare disorders. Nonetheless, the potential link between SCRIB and ASD-relevant social phenotypes has not been investigated yet. Hence, we performed an extensive behavioral characterization of the circletail line that carries a mutated version of Scrib. Scribcrc/+ mice displayed reduced social interest, lack of preference for social novelty and social reward, and reduced social habituation while other behavioral domains were unaltered. Social deficits were associated with reduced hippocampal volume, upregulation of ERK phosphorylation in specific hippocampal regions, together with increased c-Fos activity in the same brain areas. Importantly, the social alterations were rescued by both direct and indirect pERK inhibition. These results support a specific link between polarity genes, social behaviors and hippocampal functionality, thus suggesting a role for SCRIB in the etiopathology of neurodevelopmental disorders. Furthermore, our data demonstrate the crucial role of the MAPK/ERK signaling pathway, in underlying the social deficits induced by SCRIB mutation, thus supporting its relevance as a therapeutic target.

neuroscience↗

bioRxiv2019

Selective neurodevelopmental and behavioral deficits in Scrib conditional knock-out mice recapitulate some phenotypes associated with the Verheij/8q23.4 deletion syndrome.

Neurodevelopmental disorders arise from combined defects in processes including cell proliferation, differentiation, migration and commissure formation. The evolutionarily conserved tumor-suppressor protein Scribble (Scrib) serves as a nexus to transduce signals for the establishment of apicobasal and planar cell polarity during these processes. Human SCRIB gene mutations are associated with neural tube defects and this gene is located in the minimal critical region deleted in the rare Verheij syndrome. In this study, we generated brain-specific conditional cKO mouse mutants and assessed the impact of the Scrib deletion on brain morphogenesis and behavior. We showed that embryonic deletion of Scrib in the telencephalon leads to cortical thickness reduction (microcephaly) and alteration of interhemispheric connectivity (corpus callosum and hippocampal commissure agenesis). We correlated these phenotypes with the identification of novel roles for Scrib, both cell- and non-cell-autonomous, on neuronal migration and axonal guidance respectively. Finally, we show that Scrib cKO mice have psychomotor deficits such as locomotor activity impairment and memory alterations. Altogether, we show that Scrib is essential for early brain development and that the outcomes of its brain-specific disruption support a direct or indirect participation of Scrib to neurodevelopmental pathologies.

neuroscience↗