Biology subjects

Paglini, M. G.

Publications and source records attributed to Paglini, M. G..

4 recordsLinked to original sources

bioRxiv2025

Sex-specific effects of psychoactive drugs on memory performance in an animal model of Attention-Deficit Hyperactivity Disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental condition characterized by persistent deficits in working memory (WM) and executive control. Dysregulation of the Cyclin-dependent kinase 5 (Cdk5)/p35 signaling pathway has been implicated in ADHD pathophysiology due to its impact on neuronal connectivity and dopamine regulation. Using p35 knockout (p35KO) mice--an animal model exhibiting ADHD-like phenotypes--we investigated WM performance, task-related c-Fos-IR expression under basal conditions as a function of sex and genotype, as well as WM responses to acute treatment with methylphenidate (MPH) or fluoxetine (FLX), administered alone or in combination. Under basal conditions, p35KO mice exhibited significantly reduced spontaneous alternation in the Y-maze test compared with wild type (WT), whereas recognition memory remained intact. Analysis of c-Fos-IR expression, used as a marker of task-related neuronal activity, revealed region- and genotype-dependent differences, with effects of sex. p35KO animals showed reduced c-Fos-IR expression in prefrontal cortical regions and increased expression in hippocampal regions. Acute MPH or FLX treatment significantly increased spontaneous alternation in p35KO males, whereas this effect was not observed following combined treatment (MPH+FLX). In WT mice, treatment with MPH, FLX, or MPH+FLX reduced spontaneous alternation, particularly evident in females. Exploratory activity was increased in p35KO mice independently of treatment. These findings support a role for Cdk5/p35 signaling in the prefrontal-hippocampal activation patterns associated with WM testing and indicate that behavioral and pharmacological responses in this model vary according to sex and neurobiological background, highlighting the importance of considering sex as a biological variable in preclinical and translational ADHD research. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/696253v3_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@10f3aeorg.highwire.dtl.DTLVardef@ee28a5org.highwire.dtl.DTLVardef@1ae7152org.highwire.dtl.DTLVardef@191c061_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2022

Actin cytoskeleton dynamics affect replication of Human Metapneumovirus

Human Metapneumovirus (hMPV) is responsible for viral respiratory infection with clinical and epidemiological relevance in pediatric, immunocompromised, and elderly populations. Little is known about hMPV in vitro replication processes and their relationship with cellular structures such as the cytoskeleton. Our goal was to evaluate the role of the actin cytoskeleton in hMPV replication at different stages of viral growth. hMPV was isolated in Vero cells from a clinical sample and identified as A2 genotype. The cytopathic effect was detected by the appearance of cell rounding and refractory cell clusters. The growth curve showed that viral replication maximum level was between 48 and 72 hpi. The highest percentage of infected cells and intracellular hMPV-protein were detected at the early stages of the replication cycle. Disruption of actin microfilaments with Cytochalasin D during the early events provoked an increase in both intracellular and extracellular viruses. We demonstrate that the early phase of the hMPV curve is crucial for viral replication; and the disruption of microfilaments during this time increments both viral protein expression and release of viruses to the extracellular space. This study contributes to elucidate wild-type hMPV growth kinetics, providing new insights on the actin cytoskeleton role in viral replication mechanisms.

microbiology↗

bioRxiv2022

Functional entry of Members of Venezuelan Equine Encephalitis Complex into host cells is dependent on clathrin-mediated endocytosis, in a pH-Dependent Manner

Pixuna virus (PIXV) and Rio Negro virus (RNV) are mosquito-borne alphaviruses belonging to the Venezuelan Equine Encephalitis (VEE) complex, which includes pathogenic epizootic and enzootic subtypes responsible for life-threatening diseases in equines. Considering that the first steps in viral infection are crucial for the efficient production of new progeny, the aim of this study was to elucidate the early events of the replication cycle of these two viruses. To this end, we used chemical inhibitors and the expression of dominant-negative constructs to study the dependence of clathrin and endosomal pH on PIXV and RNV internalization mechanisms. We demonstrated that both viruses are internalized primarily via clathrin-mediated endocytosis, where the low pH in endosomes is crucial for viral replication. Contributing knowledge regarding the entry route of VEE complex members is important to understand the pathogenesis of these viruses and also to develop new antiviral strategies.

microbiology↗

bioRxiv2021

A New Old Tale: Dopamine Transporter implications in an animal model of Attention-Deficit Hyperactivity Disorder

Attention deficit/Hyperactivity disorder (ADHD) is one of the most diagnosed psychiatric disorders nowadays. The core symptoms of the condition include hyperactivity, impulsiveness and inattention. The main pharmacological treatment consists of psychostimulant drugs affecting Dopamine Transporter (DAT) function. We have previously shown that genetically modified mice lacking p35 protein (p35KO), which have reduced Cdk5 activity, present key hallmarks resembling those described in animal models useful for studying ADHD. The p35KO mouse displays spontaneous hyperactivity and shows a calming effect of methylphenidate or amphetamine treatment. Interestingly, dopaminergic neurotransmission is altered in these mice as they have an increased Dopamine (DA) content together with a low DA turnover. This led us to hypothesize that the lack of Cdk5 activity affects DAT expression and/or function in this animal model. In this study, we performed biochemical assays, cell-based approaches, quantitative fluorescence analysis and functional studies that allowed us to demonstrate that p35KO mice exhibit decreased DA uptake and reduced cell surface DAT expression levels in the striatum (STR). These findings are supported by in vitro observations in which the inhibition of Cdk5 activity in N2a cells induced a significant increase in constitutive DAT endocytosis with a concomitant increase in DAT localization to recycling endosomes. Taken together, these data provide evidences regarding the role of Cdk5/p35 in DAT expression and function, thus contributing to the knowledge of DA neurotransmission physiology and also providing therapeutic options for the treatment of DA pathologies such as ADHD.

neuroscience↗