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Subtype 3 metabotropic glutamate receptor (mGlu3R) displays a broad range of neuroprotective effects. We previously demonstrated that mGlu3R activation in astrocytes protects hippocampal neurons from Aβ neurotoxicity through stimulation of both neurotrophin release and Aβ uptake. Alternative-spliced variants of mGlu3R were found in human brains. The most prevalent variant, mGlu3Δ4, lacks exon 4 encoding the transmembrane domain and can inhibit ligand binding to mGlu3R. To date, neither its role in neurodegenerative disorders nor its endogenous expression in CNS cells has been addressed. The present paper describes for the first time an association between altered hippocampal expression of mGlu3Δ4 and Alzheimer's disease (AD) in the preclinical murine model PDAPP-J20, as well as a deleterious effect of mGlu3Δ4 in astrocytes. As assessed by western blot, hippocampal mGlu3R levels progressively decreased with age in PDAPP-J20 mice. On the contrary, mGlu3Δ4 levels were drastically increased with aging in nontransgenic mice, but prematurely over-expressed in 5-month-old PDAPP-J20-derived hippocampi, prior to massive senile plaque deposition. Also, we found that mGlu3Δ4 co-precipitated with mGlu3R mainly in 5-month-old PDAPP-J20 mice. We further showed by western blot that primary cultured astrocytes and neurons expressed mGlu3Δ4, whose levels were reduced by Aβ, thereby discouraging a causal effect of Aβ on mGlu3Δ4 induction. However, heterologous expression of mGlu3Δ4 in astrocytes induced cell death, inhibited mGlu3R expression, and prevented mGlu3R-dependent Aβ glial uptake. Indeed, mGlu3Δ4 promoted neurodegeneration in neuron-glia co-cultures. These results provide evidence of an inhibitory role of mGlu3Δ4 in mGlu3R-mediated glial neuroprotective pathways, which may lie behind AD onset.

With the miniaturization of electronic-based devices, the foreseen potential of new optical nanoprobes and the assessment of eventual size and shape effects, elaboration of multifunctional noncentrosymmetric nanocrystals with ferroelectric, pyroelectric, piezoelectric, and nonlinear optical properties are the subject of an increasing research interest. Here, the recent achievements from the solution-based methods (coprecipitation in homogeneous and nanostructured media, sol-gel processes including various chemistries and hydro/solvothermal techniques) to prepare 0-D perovskite and nonperovskite oxides in the 5-500 nm size range are critically reviewed. To cover a representative list of covalent- and ionic-type materials, BaTiO

Parkinson’s Disease is a neurodegenerative disorder characterized by the progressive loss of dopaminergic cells of thesubstantia nigra pars compacta. Even though successful transplantation of dopamine-producing cells into the striatum exhibits favourable effects in animal models and clinical trials; transplanted cell survival is low. Since every transplant elicits an inflammatory response which can affect cell survival and differentiation, we aimed to studyin vivoandin vitrothe impact of the pro-inflammatory environment on human dopaminergic precursors. We first observed that transplanted human dopaminergic precursors into the striatum of immunosuppressed rats elicited an early and sustained activation of astroglial and microglial cells after 15 days post-transplant. This long-lasting response was associated with Tumor necrosis factor alpha expression in microglial cells.In vitroconditioned media from activated BV2 microglial cells increased cell death, decreased Tyrosine hydroxylase -positive cells and induced morphological alterations on human neural stem cells-derived dopaminergic precursors at two differentiation stages: 19 days and 28 days. Those effects were ameliorated by inhibition of Tumor necrosis factor alpha, a cytokine which was previously detectedin vivoand in conditioned media from activated BV-2 cells. Our results suggest that a pro-inflammatory environment is sustained after transplantation under immunosuppression, providing a window of opportunity to modify this response to increase transplant survival and differentiation. In addition, our data show that the microglia-derived pro-inflammatory microenvironment has a negative impact on survival and differentiation of dopaminergic precursors. Finally, Tumor necrosis factor alpha plays a key role in these effects, suggesting that this cytokine could be an interesting target to increase the efficacy of human dopaminergic precursors transplantation in Parkinson’s Disease.

Nous avons étudié les propriétés optiques de nanocristaux de niobate de lithium dopés par des ions erbium. Ces nanocristaux émettent simultanément, sous excitation femtoseconde à 800 nm, des signaux de génération de second harmonique et de photoluminescence excitée par up-conversion.

The management of dental emergencies is a central and essential issue in the daily practice of dentists. Through two clinical studies, we were able to identify new perspectives: 1/ The strategy of emergency management based on triage with the establishment of recommendations allowed to find an effective compromise between limiting the admission of patients and ensuring the control of their pain and the relief of their symptoms. 2/ More conservative management of irreversible pulpitis. Our data tend to support pulpotomy as an acceptable and more conservative permanent treatment option for irreversible pulpitis of mature molars. Our strategies could be considered as first-line treatments, thus providing additional steps in the therapeutic gradient. (DENT - Sciences dentaires) -- UCL, 2022

The objective of this work was to evaluate (1) the short-term evolution of pain and (2) the treatment success of full pulpotomy as permanent treatment of irreversible pulpitis in mature molars. The study consisted of a non-randomized comparison between a test group (n = 44)—full pulpotomy performed by non-specialist junior practitioners, and a control group (n = 40)—root canal treatments performed by specialized endodontists. Short-term pain score (Heft–Parker scale) was recorded pre-operatively, then at 24 h and 7 days post-operatively. Three outcomes were considered for treatment success: radiographic, clinical and global success. For short-term evolution of pain, a non-parametric Wilcoxon test was performed (significance level = 0.05). For treatment success, a Pearson Chi square or Fisher test were performed (significance level = 0.017–Bonferroni correction). There was no significant difference between test and control groups neither regarding short term evolution of pain at each time point, nor regarding clinical (80% and 90%, respectively) or global success (77% and 67%, respectively). However, a significant difference in radiographic success was observed (94% and 69%, respectively). The present work adds to the existing literature to support that pulpotomy as permanent treatment could be considered as an acceptable and conservative treatment option, potentially applied by a larger population of dentists.