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Biology subjects

Contini, C.

Publications and source records attributed to Contini, C..

3 recordsLinked to original sources

Intramembrane protease SPPL2b deficiency linked to synaptic proteostasis remodeling with brain aging

Signal peptide peptidase-like 2b (SPPL2b) is a brain-enriched intramembrane protease implicated in synaptic function, immune signaling, and neuronal development, but its physiological role in brain and neuronal homeostasis remains poorly understood. We investigated the impact of constitutive Sppl2b deletion on the brain proteome and neuronal function using quantitative shotgun proteomics in cortex and hippocampus from wild-type and SPPL2b-deficient mice at 3 and 12 months, combined with western blot, immunofluorescence, dendritic spine analysis, and behavioral testing. SPPL2b deficiency was associated with alterations in biological processes linked to axonal transport and synaptic vesicle trafficking, including consistent upregulation of the kinesin motor protein KIF1A and vesicle-associated membrane protein 2 (VAMP2). SPPL2b deletion also attenuated age-associated proteomic changes in synaptic pathways and was accompanied by increased dendritic spine density, morphological remodeling of pyramidal neurons, increased locomotor activity, and reduced anxiety-like behavior. These findings reveal a previously unrecognized association between SPPL2b and synaptic proteome remodeling during aging and nominate SPPL2b-dependent pathways as candidates for further mechanistic and functional investigation in neurodegenerative disease.

neuroscience↗

A Multiscale study of phosphorylcholine driven cellular phenotypic targeting

Phenotypic targeting requires the ability of the drug delivery system to discriminate over cell populations expressing a particular receptor combination. Such selectivity control can be achieved using multiplexed-multivalent carriers often decorated with multiple ligands. Here, we demonstrate that the promiscuity of a single ligand can be leveraged to create multiplexed-multivalent carriers achieving phenotypic targeting. We show how the cellular uptake of poly(2-methacryloyloxyethyl phosphorylcholine)-poly(2- (diisopropylamino)ethyl methacrylate) (PMPC-PDPA) polymersomes varies depending on the receptor expression among different cells. We investigate the PMPC-PDPA polymersome insertion at the single chain/receptor level using all-atom molecular modelling. We propose a theoretical statistical mechanics-based model for polymersome-cell association that explicitly considers the interaction of the polymersome with the cell glycocalyx shedding light on its effect on the polymersome binding. We validate our model experimentally and show that the binding energy is a non-linear function, allowing us to tune interaction by varying the radius and degrees of polymerisation. Finally, we show that PMPC-PDPA polymersomes can be used to target monocytes in vivo due to their promiscuous interaction with SRB1, CD36 and CD81.

biochemistry↗

Towards predictive nanotoxicology: from roundabout of molecular events to chronic inflammation prediction

Nanomaterial-induced diseases cannot be reliably predicted because of the lack of clearly identified causal relationships, in particular between acute exposures and chronic symptoms. By applying advanced microscopies and omics to in vitro and in vivo systems, together with in silico molecular modelling, we have here determined that the long-lasting response to a single exposure originates in the counteracting of a newly discovered nanomaterial quarantining and nanomaterial cycling among different lung cell types. This allows us to predict the nanomaterial-induced spectrum of lung inflammation using only in vitro measurements and in silico modelling. Besides its profound implications for cost-efficient animal-free predictive toxicology, our work also paves the way to a better mechanistic understanding of nanomaterial- induced cancer, fibrosis, and other chronic diseases.

molecular biology↗