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The growing elderly population world widely prompts the need for studies regarding aged brain and its susceptibility to neurodegenerative diseases. It has been shown that aged brain exhibits several alterations, including neuroinflammation, which prone this organ to neurodegenerative processes. Metabotropic glutamate receptor 5 (mGlu5 receptor) has a role in neuronal cell loss and inflammation. Although the relevance of mGlu5 receptor in different diseases has been investigated, its involvement in normal brain aging remains unclear. In the present study, we used the mGlu5 receptor knockout (mGluR5−/−) mice, a model of Huntington's Disease (BACHD), and the double mutant mice (mGluR5−/−/BACHD), at the ages of 2, 6 and 12 months, to investigate whether mGlu5 receptor has a role in brain aging. We demonstrated that mGluR5−/− mice exhibit diminished number of neurons at 12 months of age in the cortex and striatum, similarly to what was observed in the case of BACHD and mGluR5−/−/BACHD mice. In addition, ablation of mGlu5 receptor increased the number of astrocytes and microglia in BACHD and wild type (WT) mice in an age-dependent manner in the cortical region, but not in the striatum. Interestingly, 12-month-old mGluR5−/− mice induced microglia activation, evidenced by increased CD68 expression and diminished number of microglia ramifications in skeleton analyses. Importantly, the presence of mutant huntingtin and the absence of mGlu5 receptor promoted decreased levels of fractalkine expression in aged mice, which could account for the decreased levels of microglia activation in these mice. Together, our data provide evidence that mGlu5 receptor plays a role in brain aging by modulating different cell types in the central nervous system (CNS).

Huntington's Disease (HD) is an autosomal-dominant neurodegenerative disorder, characterized by involuntary body movements, cognitive impairment, and psychiatric disorder. The metabotropic glutamate receptor 5 (mGluR5) plays an important role in HD and we have recently demonstrated that mGluR5-positive allosteric modulators (PAMs) can ameliorate pathology and the phenotypic signs of a mouse model of HD. In this study, we investigated the molecular mechanisms involved in mGluR5 PAMs effect on memory. Our results demonstrate that subchronic treatment with the mGluR5 PAM VU0409551 was effective in reversing the memory deficits exhibited by BACHD mice, a mouse model for HD. Moreover, VU0409551 treatment stabilized mGluR5 at the cellular plasma membrane of BACHD mice, increasing the expression of several genes important for synaptic plasticity, including c-Fos, brain-derived neurotrophic factor, Arc/Arg3.1, syntaxin 1A, and post-synaptic density-95. In addition, VU0409551 treatment also increased dendritic spine density and maturation and augmented the number of pre-synaptic sites. In conclusion, our results demonstrate that VU0409551 triggered the activation of cell signaling pathways important for synaptic plasticity, enhancing the level of dendritic spine maturation and rescuing BACHD memory impairment. OPEN PRACTICES: Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/.

Cutaneous mast cell tumours (cMCTs) are one of the most common cutaneous tumours in ferrets (Mustela putorius furo). However, limited information is available regarding cytological and histological features of these tumours and studies evaluating KIT expression are lacking in this species. The aims of this prospective study were to describe the most common clinical, cytological and histological features of cMCTs in ferrets and to compare the usefulness of different staining techniques in the diagnosis of these tumours in ferrets as well as evaluating KIT expression in neoplastic mast cells (MCs) by immunohistochemistry. Macroscopically, the tumours were small, round to plaque-like and frequently associated with surface crusting. The most common locations were the extremities and the trunk. MC granules were stained in all cases using toluidine blue (TB) and Wright-Giemsa stains in cytological specimens, but none stained with modified Wright's stain. Haematoxylin and eosin and TB on histological sections failed to stain MC granules in all the cases. Cytological and histological examination revealed low to moderate anisocytosis and anisokaryosis. An infiltrative rather than a delineated or encapsulated growth pattern was noted histologically in all cases. Eosinophilic infiltration was not uncommon and 'collagenolysis' was detected on cytological and histological examination. KIT expression was detected in all cases evaluated. In approximately one third of the cases the MCs exhibited KIT labelling pattern I and in the remaining ferrets, KIT pattern III. No correlation was found between KIT expression pattern and biological behaviour.

Alzheimer’s Disease (AD) is a progressive neurodegenerative disease and the main cause of dementia. Substantial evidences indicate that there is over-activation of the PI3K/Akt/mTOR axis in AD. Therefore, the aim of the present study was to investigate the effects of NVP-BEZ235 (BEZ; dactolisib), a dual PI3K/mTOR inhibitor that is under phase I/II clinical trials for the treatment of some types of cancer, in hippocampal neuronal cultures stimulated with amyloid-β (Aβ) 1–42 and in mice injected with Aβ 1–42 in the hippocampus. In cell cultures, BEZ reduced neuronal death induced by Aβ. BEZ, but not rapamycin, a mTOR inhibitor, or LY294002, a PI3K inhibitor that also inhibits mTOR, reduced the memory impairment induced by Aβ. The effect induced by Aβ was also prevented in PI3Kγ−/− mice. Neuronal death and microgliosis induced by Aβ were reduced by BEZ. In addition, the compound increased IL-10 and TNF-α levels in the hippocampus. Finally, BEZ did not change the phosphorylation of Akt and p70s6K, suggesting that the involvement of PI3K and mTOR in the effects induced by BEZ remains controversial. Therefore, BEZ represents a potential strategy to prevent the pathological outcomes induced by Aβ and should be investigated in other models of neurodegenerative conditions.

Sublethally irradiated mice were injected with recombinant cytokines to stimulate haemopoietic reconstitution. Interleukin (IL)-11 and IL-6 were able to significantly accelerate the recovery of thymus, spleen and bone marrow cells when used in combination with IL-3, but not alone. Stem cell factor (SCF) also displayed detectable effects when used with IL-3. Conversely, the IL-6 superagonist K-7/D-6 was able, even when used alone, to induce recovery of thymus, spleen and bone marrow cells up to the level of unirradiated controls. Together, these results indicate that it is possible to attain complete recovery of lymphoid organs and tissues as early as 7 d after irradiation by use of haemopoietic cytokines.

Purified CD4+ cells from the spleens of C57BL/6 mice were stimulated with anti-CD3, anti-CD28 and anti-cytotoxic T lymphocyte antigen (CTLA)-4 monoclonal antibodies. The results show that CTLA-4 stimulation inhibits IL-2 production induced by CD3-CD28 co-stimulation. Since CD3-CD28 co-stimulation induces IkappaBalpha degradation and consequently activates RelA, an NFkappaB family member relevant for the induction of IL-2 mRNA transcription, we tested whether the inhibitory effect of CTLA-4 stimulation interferes with this mechanism. CD3-CD28 co-stimulation was found to induce a drastic decrease in cytoplasmic IkappaBalpha and increase in nuclear RelA. CTLA-4 stimulation abrogates this effect of co-stimulation by increasing the level of cytoplasmic IkappaBalpha and decreasing the nuclear RelA level and DNA-binding activity. In conclusion, our results indicate that the inhibitory effect of CTLA-4 engagement on cytokine production correlates with prevention of IkappaBalpha degradation and inhibition of RelA nuclear translocation.

Two-month-old male mice were exposed to whole-body hyperthermic treatment in a circulating water bath. After 1 h exposure to 41 degrees C, mice were kept at room temperature for 24, 48, 72, and 96 h before thymus examination. The total thymocyte number progressively decreased after 24 and 48 h, reached a minimum value at 72 h, and returned to almost normal value after 96 h. Similar changes occurred in the CD4+CD8+ cell subset. Conversely, the percentage of CD4-CD8- cells rose to a maximum at 48 h and then declined to normal value at 96 h. The percentage of CD4-CD8+ and CD4+CD8- cell subsets increased to a maximum at 48 h and then declined to normal value at 96 h. These variations in single positive cell subsets correlated well with similar changes in the thymocyte mitotic response to concanavalin A. The observed effects on thymocytes were heat dose dependent, and suggest that hyperthermia induces the development of the most primitive thymocytes and positively selects mature T cells with high mitotic responsiveness. It is proposed that heat shock proteins might be involved in the hyperthermia-induced alterations of thymocyte maturation and selection.

Popliteal lymph node T cells from mice footpad-primed with azobenzenearsonate (ABA)-protein conjugates were able to help the anti-trinitrophenyl (TNP) and anti-ABA plaque-forming cell (PFC) responses of normal syngeneic spleen cells cultured in vitro with TNP-ABA-keyhole limpet haemocyanin. Enrichment in ABA-specific helper cells was obtained by positive selection of ABA-primed T cells on ABA-pulsed syngeneic macrophages. The ABA-specific T cells induced by ABA-protein priming are able to help the anti-TNP PFC response of normal B cells through recognition of the ABA determinant either unlinked to TNP (ABA and TNP separately presented to T and B cells) or linked to TNP (ABA and TNP presented as moieties of the same molecule). These two mechanisms of T-B cooperation are mediated by two different ABA-specific helper T-cell subpopulations, which can be distinguished by their different radiosensitivities: the former mechanism is mediated by radioresistant T cells, whereas the latter is mediated by radiosensitive T cells. Both helper T-cell subpopulations bind the ABA-pulsed syngeneic macrophages, demonstrating the presence of ABA-specific receptors on both cell types.

The ability to produce agglutinins against rat or sheep RBC was investigated in isologous fetal liver chimeras at 1 hour, and 15, 30, 45, and 60 days after irradiation and the response tested 14 days later. The recovery of these immune responses was not complete at 60 days after the treatment. The ability to respond against sheep RBC recovered faster and to a greater extent than did that against rat RBC.

SummaryThe serum level of IgM, IgA, IgG1 and IgG2 was studied in mice exposed to 1000–5000 R of x-rays. The serum concentration of all classes was found to decrease during the first 72 hours after irradiation. At 72 hours after 2000–5000 R, the percentage of the initial value ranged from 53 to 70 for IgM, from 24 to 44 for IgA, from 63 to 70 for IgG1, and from 55 to 71 for IgG2. If several mechanisms may account for the decrease of each Ig class, the more pronounced fall of the serum level of IgA can clearly be related to the radiation induced lesions of the intestinal mucosa.

The metabotropic glutamate receptor 5 (mGluR5) and the cannabinoid receptor 1 (CB1) exhibit a functional interaction, as CB1 regulates pre-synaptic glutamate release and mGluR5 activation increases endocannabinoid synthesis at the post-synaptic site. Since both mGluR5 and CB1 promote neuroprotection, we delineated experiments to investigate a possible link between CB1 and mGluR5 activation in the induction of neuroprotection using primary cultured corticostriatal neurons. We find that either the pharmacological blockade or the genetic ablation of either mGluR5 or CB1 can abrogate both CB1- and mGluR5-mediated neuroprotection against glutamate insult. Interestingly, decreased glutamate release and diminished intracellular Ca2+ do not appear to play a role in CB1 and mGluR5-mediated neuroprotection. Rather, these two receptors work cooperatively to trigger the activation of cell signaling pathways to promote neuronal survival, which involves MEK/ERK1/2 and PI3K/AKT activation. Interestingly, although mGluR5 activation protects postsynaptic terminals and CB1 the presynaptic site, intact signaling of both receptors is required to effectively promote neuronal survival. In conclusion, mGluR5 and CB1 act in concert to activate neuroprotective cell signaling pathways and promote neuronal survival. Electronic supplementary material The online version of this article (doi:10.1186/s13041-016-0259-6) contains supplementary material, which is available to authorized users.

Globuli rossi di pecora inducono in vitro, in colture miste di cellule spleniche di topi timectomizzati e timociti di topi normali, una risposta immune di tipo emolitico paragonabile a quella di cellule spleniche di topi normali. I dati indicano che la risposta immune delle colture miste risulta dall'interazione dell'antigene con timociti e cellule spleniche di origine midollare.