Unravelling neuroinflammatory pathways by using in vitro and in vivo models

Neuroinflammation is a crucial component of several disorders affecting central nervous system, such as neurodegenerative and neurodevelopmental diseases. In this regard, the aim of this thesis was to study different mechanisms involved in neuroinflammatory pathways, by using in vitro and in vivo models. During the first part, an in vitro study was carried out, by focusing on the analysis of the role of metabotropic glutamate receptors (mGlu)2 and 3, mGlu receptors belonging to class II, on the functions of the blood brain barrier (BBB) under inflammatory conditions. In particular, we evaluated the role of microglia in the modulation of BBB functions. To this purpose, we used a human microvascular endothelial cell line (TY-10), cultured alone or in co-culture with human astrocytes (hAst) or in a triple-culture with astrocytes and a human microglial cell line (HMC3) as an in vitro BBB model. We evaluated the transendothelial electrical resistance (TEER), barrier permeability, endothelial expression of the junctional protein claudin-5 and gene expression of inflammatory cytokines and chemokines. From our results, it might be hypothesized that mGluR3 and mGluR2 preserve BBB functions in the presence of an inflammatory insult, acting directly on the endothelial cells and contrasting the inflammatory response of astrocytes and microglia. During the second part, I moved to in vivo studies, being involved in a project in which we analyzed the complex mechanisms underlying ASD behavioural dysfunctions, by using the BTBR strain, an idiopathic mouse model of ASD. In this context, we firstly investigated neurochemical and biomolecular alterations underlying ASD-like behavioural impairments in brain regions crucially involved in ASD, such as prefrontal cortex (PFC) and hippocampus (HIPP). Subsequently, we evaluated the effect of a possible treatment to prevent ASD typical alterations, by using β-carotene administration during pregnancy in order to understand whether such antioxidant and antinflammatory compound could be useful to improve ASD core symptoms and to modulate the neuroinflammatory components in ASD offspring. The molecular characterization of the BTBR strain suggested that such idiopathic animal model might be useful to understand neurobiological and neurochemical correlates underlying ASD behavioural dysfunctions, highlighting the important role of neurotransmitter and neurotrophin alterations in specific brain regions, i.e. HIPP and PFC. Furthermore, our results showed that β-carotene treatment during pregnancy was able to counteract different ASD behavioural impairments in the offspring, together with the amelioration of the neuroinflammation typically occurring in these neurodevelopmental pathologies, finally suggesting a promising effect to prevent ASD-related dysfunctions.