We previously demonstrated that Npy1r^rfb mice, which carry the conditional inactivation of the Npy1r gene in forebrain principal neurons, display a sexually dimorphic phenotype, with male mice showing metabolic, hormonal and behavioral effects and females being only marginally affected. Moreover, exposure of Npy1r^rfb male mice to a high-fat diet (HFD) increased body weight growth, adipose tissue, blood glucose levels and caloric intake compared to Npy1r^2lox male controls. We used conditional knockout Npy1r^rfb and Npy1r^2lox control mice to examine whether forebrain disruption of the Npy1r gene affects susceptibility to obesity and associated disorders of cycling and ovariectomized (ovx) female mice in a standard diet (SD) regimen or exposed to an HFD for 3 months. The conditional deletion of the Npy1r gene increased body weight and subcutaneous white adipose tissue weight in both SD- and HFD-fed ovx females but not in cycling females. Moreover, compared with ovx control females on the same diet regimen, Npy1r^rfb females displayed increased microglia number and activation, increased expression of Neuropeptide Y (NPY)-immunoreactivity (IR) and decreased expression of proopiomelanocortin-IR in the hypothalamic arcuate nucleus (ARC). These results suggest that in the ARC NPY-Y1R reduces the susceptibility to obesity of female mice with low levels of gonadal hormones and that this effect may be mediated via NPY-Y1R ability to protect the brain against neuroinflammation.

NPY and its Y1 cognate receptor (Y1R) have been shown to be involved in the regulation of stress, anxiety, depression and energy homeostasis. We previously demonstrated that conditional knockout of Npy1r gene in the excitatory neurons of the forebrain of adolescent male mice (Npy1r^rfb mice) decreased body weight growth and adipose tissue and increased anxiety. In the present study, we used the same conditional system to examine whether the targeted disruption of the Npy1r gene in limbic areas might affect susceptibility to obesity and associated disorders during adulthood in response to a 3-week high-fat diet (HFD) regimen. We demonstrated that following HFD exposure, Npy1r^rfb male mice showed increased body weight, visceral adipose tissue, and blood glucose levels, hyperphagia and a dysregulation of calory intake as compared to control Npy1r^2lox mice. These results suggest that low expression of Npy1r in limbic areas impairs habituation to high caloric food and causes high susceptibility to diet-induced obesity and glucose intolerance in male mice, uncovering a specific contribution of the limbic Npy1r gene in the dysregulation of the eating/satiety balance.

We investigated the role of PI3Kγ in oral carcinogenesis by using a murine model of oral squamous carcinoma generated by exposure to 4-nitroquinoline 1-oxide (4NQO) and the continuous human cancer cell line HSC-2 and Cal-27. PI3Kγ knockout (not expressing PI3Kγ), PI3Kγ kinase-dead (carrying a mutation in the PI3Kγ gene causing loss of kinase activity) and wild-type (WT) C57Bl/6 mice were administered 4NQO via drinking water to induce oral carcinomas. At sacrifice, lesions were histologically examined and stained for prognostic tumoral markers (EGFR, Neu, cKit, Ki67) and inflammatory infiltrate (CD3, CD4, CD8, CD19 and CD68). Prevalence and incidence of preneoplastic and exophytic lesions were significantly and similarly delayed in both transgenic mice versus the control. The expression of prognostic markers, as well as CD19⁺ and CD68⁺ cells, was higher in WT, while T lymphocytes were more abundant in tongues isolated from transgenic mice. HSC-2 and Cal-27 cells were cultured in the presence of the specific PI3Kγ-inhibitor (IPI-549) which significantly impaired cell vitality in a dose-dependent manner, as shown by the MTT test. Here, we highlighted two different mechanisms, namely the modulation of the tumor-infiltrating cells and the direct inhibition of cancer-cell proliferation, which might impair oral cancerogenesis in the absence/inhibition of PI3Kγ.

Anxiety- and depression-related disorders are frequently associated with deficits in social behavior, including excessive aggression and violence, which may arise from disruptions in the neural circuits regulating emotions and social interactions. Sex differences play a crucial role in modulating emotional and social behaviors, particularly aggression and anxiety. Neuropeptide Y (NPY) and its Y1 receptor (Y1R) are involved in regulating various physiological functions, including emotional behavior and stress response. We previously demonstrated that conditional knockout of Npy1r gene in the forebrain excitatory neurons (Npy1r^rfb mutant mice) increased anxiety-like behavior and hypothalamus-pituitary-adrenocortical axis reactivity and decreased body weight growth in a sex-dependent manner. In the present study we investigated how the depletion of the Npy1r gene in limbic areas might affect male and female mice by using a test battery aimed at assessing anxiety-like, social and aggressive behavior as well as response to novelty. Our results showed reduced exploratory behavior and increased anxiety in response to a novel environment in Npy1r^rfb mice, with females exhibiting more pronounced effects. In contrast, only Npy1r^rfb males showed reduced neophobia and increased impulsivity in response to a novel palatable food. Moreover, reduced limbic Npy1r expression decreased territorial aggression and increased defensive behaviors only in males. These findings reveal that limbic Y1R modulates anxiety, social interaction, and aggression in a sex-dependent manner. Moreover, they uncover a novel role for Y1R in regulating intermale aggression and suggest sex-specific links between NPY-Y1R signaling and the modulation of motivational and emotional responses.

Background and Purpose: GRIN-related disorders are neurodevelopmental disorders caused by mutations in the N-methyl-D-aspartate receptor (NMDAR) subunit receptor GRIN genes. A large fraction of these mutations leads to gain of function (GoF) of the NMDAR. Patients present with a combination of symptoms that includes epilepsy, intellectual disability, behavioural and motor symptoms. Controlling seizures is a significant medical need in most patients with GRIN-related disorders. The aim of this study was to assess the therapeutic efficacy of radiprodil, a selective negative allosteric modulator of GluN2B-containing NMDARs, in counteracting audiogenic seizures (AGS) in a murine model carrying the GluN2A(N615S) mutation in homozygosity (Grin2aS/S mice). Experimental Approach: Grin2aS/S mice were acutely treated with radiprodil at different doses before the presentation of a high-frequency acoustic stimulus commonly used for AGS induction. Key Results: Radiprodil significantly and dose-dependently reduced the onset and severity of AGS in Grin2aS/S mice. Conclusion and Implications: Our data clearly indicates that radiprodil has the potential to control seizures in patients with GRIN2A GoF mutations, targeting the underlying pathophysiology of the disorder.

Neuropeptide Y (NPY) is a key regulator of energy homeostasis, acting through various receptor subtypes in both central and peripheral systems. Increasing interest has been directed toward exploiting NPY as a pharmacological target in obesity. While the orexigenic role of NPY in the hypothalamus is well established, its downstream effects on peripheral metabolism remain less defined, particularly when perturbations to the system are introduced. Previously, we observed that female mice with limbic NPY-Y1 receptor gene (Npy1r) knockout (KO) under different dietary conditions (standard, SD, or high-fat diet, HFD) accumulated more subcutaneous white adipose tissue (WAT) compared to wild-type in the absence of gonadal hormones, despite no changes in food intake. To deepen the mechanisms underlying these effects, we conducted molecular analyses on WAT of these mice. We found that Npy gene expression was upregulated in WAT of HFD-fed mice, regardless of genotype. However, NPY peptide levels were reduced in both KO and HFD groups, suggesting post-transcriptional regulation of NPY under metabolic stress. NPY-Y2 receptor gene (Npy2r) expression in WAT was significantly increased in both KO and HFD while Npy1r expression in WAT remained unchanged across groups. Genes involved in WAT metabolism were similarly upregulated in both KO and HFD mice, indicating that limbic Npy1r KO mimics some of the metabolic effects induced by HFD. Correlation analysis suggests that dysregulated NPY signalling may promote increased lipid storage and reduce energy expenditure. Overall, these findings highlight the complex interplay between central and peripheral NPY signalling emphasizing the importance of caution when investigating therapeutic strategies targeting single NPY receptors. Overall, these findings highlight the complex interplay between central Npy1r signalling and peripheral adipose tissue regulation. They also emphasize the importance of caution when investigating new therapeutic strategies targeting single NPY receptors, as central interventions may provoke maladaptive metabolic responses in peripheral tissues.