Biology subjects

Pesce, G.

Publications and source records attributed to Pesce, G..

5 recordsLinked to original sources

bioRxiv2026

Isolation and preliminary characterization of extracellular vesicles from bottlenose dolphin (Tursiops truncatus) and long-finned pilot whale (Globicephala melas) blow

Cetaceans are key sentinel species for environmental health monitoring. Although sampling from free-ranging animals is challenging, the analysis of cetacean blow offers a minimally invasive approach to assess their health status. Extracellular vesicles (EVs) are cell-derived nanostructures present in biological fluids and widely studied as disease biomarkers in humans. Despite the potential for similar uses, EVs have not been studied in cetacean blow to date . This proof-of-concept study aims to assess the feasibility of the isolation and characterization of EVs from blow samples collected from five bottlenose dolphins (Tursiops truncatus) kept under human care and from a free ranging specimen of long-finned pilot whale (Globicephala melas). EVs were purified from bottlenose dolphin blows by ultracentrifugation (UC) or size exclusion chromatography (SEC) and from the long-finned pilot whale by SEC. Particle concentration and size distribution were assessed by Nanoparticle Tracking Analysis (NTA), morphology by Air-atomic force microscopy (AFM) and protein expression by Western Blotting (WB). NTA revealed a higher mean particle concentration in bottlenose dolphin EVs isolated by UC compared to SEC, while EVs isolated from the long-finned pilot whale presented a lower particle concentration. AFM confirmed the presence of EV-like particles within the typical EV size range in bottlenose dolphins EVs obtained both by SEC or UC. All EV samples were positive for CD9 and integrin-{beta} and negative to Calnexin. SEC was more sensitive to detect OmpA, a membrane protein of Gram-negative bacteria, in EVs from both species. Our pilot study demonstrates that EVs are present in cetacean blow and can be isolated and characterized. Future investigations focused on characterizing and quantifying a wider array of EV associated molecules may further the application of blow EV analysis for cetacean health assessments.

zoology↗

bioRxiv2024

Redox-dependent formation of a viral amyloid and functional impact

The Hendra and Nipah viruses (HeV and NiV) are zoonotic biosafety level-4 pathogens belonging to the Paramyxoviridae family. We previously showed that their W protein, a key player in the evasion of the host antiviral response, forms highly flexible, curved fibrils in vitro. Here, we show that the cysteine oxidation state acts as a molecular switch controlling the formation of either amorphous aggregates or flexible fibrils, and that residues 2 to 29 are essential for fibrillation. We also uncover that the HeV W protein (WHeV) can also self-assemble in cellula. WHeV forms distinct types of nuclear condensates that exhibit different dependencies on the cysteine redox-state. While deletion of residues 2-29 prevents formation of nuclear filaments, cysteine-to-serine substitution mainly impairs the formation of non-filamentous condensates. Both infection and WHeV ectopic expression trigger oxidative stress presumably favorable to WHeV condensation. Finally, we show that impaired ability to form redox-sensitive, non-filamentous condensates is associated with a reduced W ability to inhibit the NF-{kappa}B pathway, while it conversely enhances W ability to repress the interferon response pathway.

biochemistry↗

bioRxiv2022

Molecular determinants of fibrillation in a viral amyloidogenic domain from combined biochemical and biophysical studies

The Nipah and Hendra viruses (NiV and HeV) are biosafety level 4 human pathogens classified within the Henipavirus genus of the Paramyxoviridae family. In both NiV and HeV, the gene encoding the Phosphoprotein (P protein), an essential polymerase cofactor, also encodes the V and W proteins. These three proteins, which share an intrinsically disordered N-terminal domain (NTD) and have unique C-terminal domains (CTD), are all known to counteract the host innate immune response, with V and W acting by either counteracting or inhibiting Interferon (IFN) signaling. Recently, using a combination of biophysical and structural approaches, the ability of a short region within the shared NTD (PNT3 region) to form amyloid-like structures was reported. Here, we evaluated the relevance of each of three contiguous tyrosine residues located in a previously identified amyloidogenic motif (EYYY) within HeV PNT3 to the fibrillation process. Our results indicate that removal of a single tyrosine in this motif significantly decreases the ability to form fibrils independently of position, mainly affecting the elongation phase. In addition, we show that the C-terminal half of PNT3 has an inhibitory effect on fibril formation that may act as a molecular shield and could thus be a key domain in the regulation of PNT3 fibrillation. Finally, the kinetics of fibril formation for the two PNT3 variants with highest and lowest fibrillation propensity were studied by Taylor Dispersion Analysis (TDA). The results herein presented shed light onto the molecular mechanisms involved in fibril formation. In addition, the PNT3 variants we generated represent valuable tools to further explore the functional impact of V/W fibrillation in transfected and infected cells.

biochemistry↗

bioRxiv2020

Meta-analysis of epigenome-wide associations between DNA methylation at birth and childhood cognitive skills.

Cognitive skills are a strong predictor of a wide range of later life outcomes. Genetic and epigenetic associations across the genome explain some of the variation in general cognitive abilities in the general population and it is plausible that epigenetic associations might arise from prenatal environmental exposures and/or genetic variation early in life. We investigated the association between cord blood DNA methylation at birth and cognitive skills assessed in children from eight pregnancy cohorts (N=2196-3798) within the Pregnancy And Childhood Epigenetics (PACE) Consortium across overall, verbal and non-verbal cognitive scores. The associations at single CpG sites were weak for all of the cognitive domains investigated. One region near DUSP22 on chromosome 6 was associated with non-verbal cognition in a model adjusted for maternal IQ. We conclude that there is little evidence to support the idea that cord blood DNA methylation at single CpGs can predict cognitive skills and further studies are needed to confirm regional differences.

developmental biology↗

bioRxiv2016

Cell-to-cell variability in the yeast pheromone response: Cytoplasmic microtubule functionstabilizes signal generation and promotes accurate fate choice

In a companion paper, we carried out a high-throughput screen to identify genes that suppressed cell-to-cell variability in signaling in yeast. Two genes affected cytoplasmic microtubules that can connect the nucleus to a signaling site on the membrane. Here, we show that microtubule perturbations that affected polymerization and depolymerization, membrane attachment, and force generation increased variability. For some perturbations, \"outlier\" cells drove the increased variability. Bypass experiments that activated the PRS ectopically at downstream points indicated that microtubule-dependent processes might stabilize the membrane-recruited scaffold protein Ste5. The variability caused by microtubule perturbations required the MAP kinase Fus3. Microtubule perturbations hindered stable scaffold formation and decreased the accuracy of a polarity-dependent fate choice. Our experiments suggest that membrane-attached microtubules stabilize signaling by scaffold-bound Fus3, and are consistent with a model in which signaling irregularities from changes in microtubule function are amplified by cross-stimulatory feedbacks among PRS proteins. The fact that microtubule perturbations also cause aberrant fate and polarity decisions during embryonic development and cancer initiation suggests that similar variation-reducing processes might also operate in metazoans.

systems biology↗