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Faivre, E.

Publications and source records attributed to Faivre, E..

3 recordsLinked to original sources

Sex-dependent effects of maternal high-fat diet during lactation in adult THY-Tau22 mice offspring

The perinatal environment has been suggested to participate to the development of tauopathies and Alzheimers disease but the molecular and cellular mechanisms involved remain contradictory and under-investigated. Here, we evaluated the effects of a maternal high-fat diet (HFD) during lactation on the development of tauopathy in the THY-Tau22 mouse strain, a model of progressive tau pathology associated with cognitive decline. During lactation, dams were fed either a chow diet (13.6% of fat) or a HFD (58% of fat). At weaning, offspring was fed a chow diet until sacrifice at 4 months of age (the onset of tau pathology) or 7 months of age (the onset of cognitive impairment). During lactation, maternal HFD increased body weight gain in offspring. At 3 months of age, maternal HFD led to a mild glucose intolerance only in male offspring. Moreover, it impaired spatial memory in both male and female 6-month-old offspring, with males being more impacted. These cognitive deficits were associated with increased phosphorylation of hippocampal tau protein-observed at 4 months in males and at 7 months in females, highlighting a sex-specific temporal shift. Additionally, maternal HFD modified adult hippocampal neurogenesis (AHN), leading to an increase of mature neuronal cells number in females and of dendritic arborization length in males. Synaptic analysis further revealed that maternal HFD led to synaptic loss only in males. Finally, multi-omics approaches showed that maternal HFD has long-term consequences on both transcriptome, proteome and regulome, this effect being also sex-dependent with mitochondrial pathways, ribosomal activity, cilium and the extracellular matrix predominantly impacted in males, while gliogenesis, myelination and synaptic plasticity were primarily affected in females. Regulome analysis suggested that this sex-dependent phenotype was more related to a temporal shift rather than distinct sex-specific alterations. Collectively, our data suggest that maternal malnutrition accelerates the development of tauopathy in THY-Tau22 offspring, with sex-dependent effects, males being impacted earlier than females. These findings highlight the critical role of the perinatal environment as a key window of opportunity for interventions aimed at preventing the development of neurodegenerative diseases.

neuroscience↗

Platelet concentrate-derived extracellular vesicles promote adult hippocampal neurogenesis

Platelet-derived materials are emerging as promising, cell-free biotherapies for regenerative medicine. While platelet lysates have shown neuroprotective activity in preclinical models, the neurogenic potential of platelet concentrate-derived extracellular vesicles (pEVs) remains underexplored. Here, we evaluated the effects of human pEVs and a neuroprotective heat-treated human platelet lysate (HPPL) on adult hippocampal neurogenesis using both an ex vivo neurosphere assay and an in vivo intranasal administration model. pEVs selectively enhanced dentate gyrus (DG)-derived neurosphere growth, even in the absence of exogenous growth factors, and were internalized by neural precursors. In vivo, short-term pEV delivery increased EdU proliferating cells in the DG, while long-term administration (28 days) elevated the proportion of newborn mature neurons. By contrast, HPPL primarily promoted early neurogenesis by expanding immature DCX neurons. Quantitative proteomics of DG tissue after pEV treatment revealed 111 differentially expressed proteins, with enrichment in pathways related to oxidative phosphorylation, Notch4 signaling, myelination, and MHC class I-mediated antigen presentation. Downregulated proteins included cytoskeletal and translation-related regulators, suggesting a shift toward neuronal differentiation and circuit integration. Biophysical characterization confirmed the purity and vesicular nature of pEVs, with a defined protein cargo including immune modulators and ECM-interacting molecules such as CD44, lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1), and complement proteins. These findings identify allogeneic pEVs as multifunctional agents that modulate neural precursor cell fate and brain tissue remodeling through coordinated metabolic and immunoregulatory mechanisms. This work supports the translational potential of pEV-based therapeutics for promoting hippocampal neurogenesis and cognitive repair in neurodegenerative and age-related brain disorders.

neuroscience↗

Caffeine consumption during pregnancy accelerates the development of cognitive deficits in offspring in a model of tauopathy

Psychoactive drugs used during pregnancy can affect the development of the brain of offspring, directly triggering neurological disorders or increasing the risk for their occurrence. Caffeine is the most widely consumed psychoactive drug, including during pregnancy. In Wild type mice, early life exposure to caffeine renders offspring more susceptible to seizures. Here, we tested the long-term consequences of early life exposure to caffeine in THY-Tau22 transgenic mice, a model of Alzheimers disease-like Tau pathology. Caffeine exposed mutant offspring developed cognitive earlier than water treated mutants. Electrophysiological recordings of hippocampal CA1 pyramidal cells in vitro revealed that early life exposure to caffeine changed the way the glutamatergic and GABAergic drives were modified by the Tau pathology. We conclude that early-life exposure to caffeine affects the Tau phenotype and we suggest that caffeine exposure during pregnancy may constitute a risk-factor for early onset of Alzheimers disease-like pathology.

neuroscience↗