Luisa Iacovelli - Academia.edu (original) (raw)

Papers by Luisa Iacovelli

Neuropharmacology, 2022

In schizophrenia, mGlu5 receptor hypofunction has been linked with neuropathology and cognitive d... more In schizophrenia, mGlu5 receptor hypofunction has been linked with neuropathology and cognitive deficits, making it an attractive therapeutic target. The cognitive impairment associated with schizophrenia remains an unmet clinical need, with existing antipsychotics primarily targeting positive symptoms, with weaker and more variable effects on cognitive deficits. Using the sub-chronic phencyclidine rat model, widely shown to mimic the cognitive impairment and neuropathology of schizophrenia, we have investigated two mGlu5 receptor positive allosteric modulators (PAMs), VU0409551 and VU0360172. We compared the efficacy of these compounds in restoring cognitive deficits and, since these two PAMs have reportedly distinct signalling mechanisms, changes in mGlu5 receptor signalling molecules AKT and MAPK in the PFC. Although not effective at 0.05 and 1 mg/kg, cognitive deficits were significantly alleviated by both PAMs at 10 and 20 mg/kg. The compounds appeared to have differential effects on the scPCP-induced increases in AKT and MAPK phosphorylation: VU0409551 induced a significant decrease in expression of p-AKT, whereas VU0360172 had this effect on p-MAPK levels. Thus, the beneficial effects of PAMs on scPCP-induced cognitive impairment are accompanied by at least partial reversal of scPCP-induced elevated levels of p-MAPK and p-AKT, whose dysfunction is strongly implicated in schizophrenia pathology. These promising data imply an important role for mGlu5 receptor signalling pathways in improving cognition in the scPCP model and provide support for mGlu5 receptor PAMs as a possible therapeutic intervention for schizophrenia.

Additional file 6: Table S1. Number of samples, statistics, and p values.

Additional file 4: Figure S4. Transfection efficiency in rat primary cultured microglia. (A, B) M... more Additional file 4: Figure S4. Transfection efficiency in rat primary cultured microglia. (A, B) Microglial cells sorted from P7 CTRL rat pups were stained with Iba1 (green) and DAPI (blue) 48h after transfection with siGLO Red Transfection indicator (25nM and 50nM). Representative photomicrographs at 10X magnification are shown in A (scale bar = 50 μm). Value are relative to the percentage of microglia siGLO Red+cells/DAPI in B. Data (mean ± SEM); four culture wells per condition (mean cells number 25nM: 141 ± 12; mean cells number 50nM: 165 ± 9). Unpaired t-test; ***p < 0.001.

Additional file 5: Figure S5. Pearson correlation between Grm3 expression and inflammatory marker... more Additional file 5: Figure S5. Pearson correlation between Grm3 expression and inflammatory markers 48h after siGrm3 transfection. (A, B) Pearson correlation between Grm3 expression and pro-inflammatory markers (A), and between Grm3 expression and anti-inflammatory/immune-regulatory markers (B), 48h after transfection with siGrm3 (50nM).

Background: Perinatal inflammation is a key factor of brain vulnerability in neonates born preter... more Background: Perinatal inflammation is a key factor of brain vulnerability in neonates born preterm or with intra-uterine growth restriction (IUGR), two leading conditions associated with brain injury and responsible for neurocognitive and behavioral disorders. Systemic inflammation is recognized to activate microglia, known to be the critical modulators of brain vulnerability. Although some evidence support a role for metabotropic glutamate receptor 3 (mGlu3 receptor) in modulation of neuroinflammation, its functions are still unknown in the developing microglia.Methods: We used a double-hit rat model of perinatal brain injury induced by a gestational low-protein diet combined with interleukin-1β injections (LPD/IL-1β), mimicking both IUGR and prematurity-related inflammation. The effect of LPD/IL-1β on mGlu3 receptor expression and the effect of mGlu3 receptor modulation on microglial reactivity were investigated using a combination of pharmacological, histological, and molecular a...

Frontiers in Psychiatry, 2019

Metabotropic glutamate (mGlu) receptors are considered as candidate drug targets for the treatmen... more Metabotropic glutamate (mGlu) receptors are considered as candidate drug targets for the treatment of schizophrenia. These receptors form a family of eight subtypes (mGlu1 to −8), of which mGlu1 and −5 are coupled to G q/11 , and all other subtypes are coupled to G i/o. Here, we discuss the possibility that selective ligands of individual mGlu receptor subtypes may be effective in controlling the core symptoms of schizophrenia, and, in some cases, may impact mechanisms underlying the progression of the disorder. Recent evidence indicates that activation of mGlu1 receptors inhibits dopamine release in the meso-striatal system. Hence, selective positive allosteric modulators (PAMs) of mGlu1 receptors hold promise for the treatment of positive symptoms of schizophrenia. mGlu5 receptors are widely expressed in the CNS and regulate the activity of cells that are involved in the pathophysiology of schizophrenia, such as cortical GABAergic interneurons and microglial cells. mGlu5 receptor PAMs are under development for the treatment of schizophrenia and cater the potential to act as disease modifiers by restraining neuroinflammation. mGlu2 receptors have attracted considerable interest because they negatively modulate 5-HT 2A serotonin receptor signaling in the cerebral cortex. Both mGlu2 receptor PAMs and orthosteric mGlu2/3 receptor agonists display antipsychotic-like activity in animal models, and the latter drugs are inactive in mice lacking mGlu2 receptors. So far, mGlu3 receptors have been left apart as drug targets for schizophrenia. However, activation of mGlu3 receptors boosts mGlu5 receptor signaling, supports neuronal survival, and drives microglial cells toward an antiinflammatory phenotype. This strongly encourages research of mGlu3 receptors in schizophrenia. Finally, preclical studies suggest that mGlu4 receptors might be targeted by novel antipsychotic drugs, whereas studies of mGlu7 and mGlu8 receptors in animal models of psychosis are still at their infancy.

Current opinion in pharmacology, Jan 8, 2018

In spite of the recent advancement in the molecular characterization of malignant gliomas and med... more In spite of the recent advancement in the molecular characterization of malignant gliomas and medulloblastomas, the treatment of primary brain tumors remains suboptimal. The use of small molecule inhibitors of intracellular signaling pathways, inhibitors of angiogenesis, and immunotherapic agents is limited by systemic adverse effects, limited brain penetration, and, in some cases, lack of efficacy. Thus, adjuvant chemo-therapy and radiotherapy still remain the gold standard in the treatment of grade-IV astrocytoma (glioblastoma multiforme) and medulloblastoma. We review evidence that supports the development of mGlu3 receptor antagonists as add-on drugs in the treatment of malignant gliomas. These drugs appear to display pleiotropic effect on tumor cells, affecting proliferation, differentiation, and response to chemotherapy. mGlu1 and mGlu4 receptors could also be targeted by potential anticancer agents in the treatment of malignant gliomas and medulloblastoma, but extensive resea...

Pharmacological Research, 2017

The version in the Kent Academic Repository may differ from the final published version. Users ar... more The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.

Neuropharmacology, Feb 18, 2016

We studied the interaction between mGlu7 and α1-adrenergic receptors in heterologous expression s... more We studied the interaction between mGlu7 and α1-adrenergic receptors in heterologous expression systems, brain slices, and living animals. L-2-Amino-4-phosphonobutanoate (L-AP4), and l-serine-O-phosphate (L-SOP), which activate group III mGlu receptors, restrained the stimulation of polyphosphoinositide (PI) hydrolysis induced by the α1-adrenergic receptor agonist, phenylephrine, in HEK 293 cells co-expressing α1-adrenergic and mGlu7 receptors. The inibitory action of L-AP4 was abrogated by (i) the mGlu7 receptor antagonist, XAP044; (ii) the C-terminal portion of type-2 G protein coupled receptor kinase; and (iii) the MAP kinase inhibitors, UO126 and PD98059. This suggests that the functional interaction between mGlu7 and α1-adrenergic receptors was mediated by the βγ-subunits of the Gi protein and required the activation of the MAP kinase pathway. Remarkably, activation of neither mGlu2 nor mGlu4 receptors reduced α1-adrenergic receptor-mediated PI hydrolysis. In mouse cortical sli...

Neuropharmacology, 2017

Cinnabarinic and xanthurenic acids are kynurenine metabolites generated by oxidative dimerization... more Cinnabarinic and xanthurenic acids are kynurenine metabolites generated by oxidative dimerization of 3-hydroxyanthranilic acid and transamination of 3-hydroxykynurenine, respectively. Recent evidence suggests that both compounds can affect brain fuction and neurotransmission and interact with metabotropic glutamate (mGlu) receptors. Cinnabarinic acid behaves as an orthosteric agonist of mGlu4 receptors, whereas some of the effects produced by xanthurenic acid in the CNS involve mGlu2 and mGlu3 receptors. Cinnabarinic acid could play an important role in mechanisms of neuroinflammation acting as a linking bridge between the immune system and the CNS. Xanthurenic acid has potential implications in the pathophysiology of schizophrenia and is a promising candidate as a peripheral biomarker of the disorder. The action of cinnabarinic acid and xanthurenic acid may extend beyond the regulation of mGlu receptors and may involve several diverse molecular targets, such as the aryl hydrocarbon receptor for cinnabarinic acid and vesicular glutamate transporters for xanthurenic acid. The growing interest on these two "unorthodox" metabolites of the kynurenine pathway may unravel new aspects in the complex interaction between tryptophan metabolism and brain function, and lead to the discovery of new potential targets for the treatment of neurological and psychiatric disorders.

Molecular Pharmacology, 2011

The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 4, 2011

DNA methylation at CpG dinucleotides is associated with gene silencing, stress, and memory. The c... more DNA methylation at CpG dinucleotides is associated with gene silencing, stress, and memory. The catechol-O-methyltransferase (COMT) Val(158) allele in rs4680 is associated with differential enzyme activity, stress responsivity, and prefrontal activity during working memory (WM), and it creates a CpG dinucleotide. We report that methylation of the Val(158) allele measured from peripheral blood mononuclear cells (PBMCs) of Val/Val humans is associated negatively with lifetime stress and positively with WM performance; it interacts with stress to modulate prefrontal activity during WM, such that greater stress and lower methylation are related to reduced cortical efficiency; and it is inversely related to mRNA expression and protein levels, potentially explaining the in vivo effects. Finally, methylation of COMT in prefrontal cortex and that in PBMCs of rats are correlated. The relationship of methylation of the COMT Val(158) allele with stress, gene expression, WM performance, and rel...

Methods in Molecular Biology, 2011

This chapter describes the protocol for the preparation of recombinant adenoviruses and infection... more This chapter describes the protocol for the preparation of recombinant adenoviruses and infection of target cells to transiently express G protein-coupled receptors (GPCRs) or other proteins of interest. Adenoviruses are non-enveloped viruses containing a linear double-stranded DNA genome. Their life cycle does not normally involve integration into the host genome, rather they replicate as episomal -elements in the nucleus of the host cell, and consequently there is no risk of insertional mutagenesis. Up to 30 kb out of the 35 kb of the wild-type adenovirus genome can be replaced by foreign DNA. Adenoviral vectors are very efficient in transducing target cells in vitro and in vivo and can be produced at high titers (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;10¹¹/mL). The viral infection has a number of useful features: (1) the efficiency of gene transduction is very high (up to 100% in sensitive cells); (2) the infection is easy and does not physically alter the cell membrane for gene transduction; (3) it is possible to infect cells that are resistant to transfection with plasmids (including nondividing cells); and (4) the viral vectors can be used for infection in vivo (including gene therapy) and can potentially be targeted cell-specifically.

Trends in Pharmacological Sciences, 2007

Cancer stem cells are currently a target for the treatment of malignant tumors. Transformed neura... more Cancer stem cells are currently a target for the treatment of malignant tumors. Transformed neural stem-progenitor cells of the brain subventricular zone and the external granular layer of the cerebellum are the putative cells of origin of malignant gliomas and medulloblastomas, which are the most frequent malignant brain tumors in adults and children, respectively. The proliferation of neural stem-progenitor cells is regulated by metabotropic glutamate (mGlu) receptors, which are G-proteincoupled receptors that are activated by glutamate, the major excitatory neurotransmitter of the CNS. At least two receptor subtypes-mGlu 3 and mGlu 4 receptorscontrol the proliferation of brain tumor cells, whereas mGlu 1 receptors have been implicated in the development of melanomas. We believe that individual mGlu receptor subtypes represent new potential targets for the treatment of several malignant tumors, including brain tumors.

Proceedings of the National Academy of Sciences, 2010

The D2/AKT1/GSK-3β signaling pathway has been involved in the downstream intracellular effects of... more The D2/AKT1/GSK-3β signaling pathway has been involved in the downstream intracellular effects of dopamine, in the pathophysiology of cognitive deficits and related brain activity in schizophrenia, as well as in response to treatment with antipsychotics. Polymorphisms in the D2 ( DRD2 rs1076560) and AKT1 ( AKT1 rs1130233) genes have been associated with their respective protein expression and with higher-order cognition and brain function, including attention. Given the strong potential for their relationship, we investigated the interaction of these polymorphisms on multiple molecular and in vivo phenotypes associated with this signaling pathway. We measured AKT1 and GSK-3β proteins and phosphorylation in human peripheral blood mononuclear cells, functional MRI cingulate response during attentional control, behavioral accuracy during sustained attention, and response to 8 wk of treatment with olanzapine in a total of 190 healthy subjects and 66 patients with schizophrenia. In healt...

Neurological Sciences, 2003

Cellular inclusions containing ubiquitin and alpha-synuclein were observed in PC12 cells treated ... more Cellular inclusions containing ubiquitin and alpha-synuclein were observed in PC12 cells treated with metamphetamine (MA). To study the possible involvement of beta-arrestin in inclusion formation, we treated PC12 cells with MA for different times and analyzed the ubiquitin proteosome pathway (UPP). We found that beta-arrestin is ubiquitinated in the MA-treated PC12 cell line. The involvement of beta-arrestin in UPP was further supported by electron microscopy and by confocal microscopy, which documented the presence of beta-arrestin in these Lewy body-like inclusions. Our experiments reveal an interesting and previously unappreciated connection between beta-arrestin and ubiquitination and suggest that beta-arrestin could be involved in the development of the inclusion bodies.

Molecular Psychiatry, 2007

Molecular Pharmacology, 2009

We examined the regulation of mGlu2 and mGlu3 metabotropic glutamate receptor signalling prompted... more We examined the regulation of mGlu2 and mGlu3 metabotropic glutamate receptor signalling prompted by the emerging role of these receptor subtypes as therapeutic targets for psychiatric disorders, such as anxiety and schizophrenia. In transfected HEK293 cells, G-protein coupled receptor kinase (GRK)2 and GRK3 fully desensitized the agonist-dependent inhibition of cAMP formation mediated by mGlu3 receptors. In contrast, GRK2 or other GRKs did not desensitize the cAMP response to mGlu2 receptor activation. Desensitization of mGlu3 receptors by GRK2 required an intact kinase activity, as shown by the use of the kinase-dead mutant GRK2-K220R or the recombinant GRK2 C-terminal domain. Overexpression of β-arrestin1 also desensitized mGlu3 receptors and did not affect the cAMP signalling mediated by mGlu2 receptors. The difference in the regulation of mGlu2 and mGlu3 receptors was signal-dependent because GRK2 desensitized the activation of the MAP kinase pathway mediated by both mGlu2 and mGlu3 receptors. In vivo studies confirmed the resistance of mGlu2 receptor-mediated cAMP signalling to homologous desensitization. Wild-type, mGlu2-/or mGlu3-/mice were treated i.p. with saline or the mixed mGlu2/3 receptor agonist, LY379268 (1 mg/kg) once daily for 7 days. Inhibition of forskolin (FSK)-stimulated cAMP formation by LY379268 was measured in cortical slices prepared 24 hours after the last injection. Agonist pre-treatment fully desensitized the cAMP response in wild-type and mGlu2-/mice, but had not effect in mGlu3-/mice in which LY379268 could only activate the mGlu2 receptor. We predict the lack of tolerance when mixed mGlu2/3 receptor agonists or selective mGlu2 enhancers are used chronically in patients.