👤 Fernanda G De Felice

The progressive accumulation of physiological stress as we age, known as allostatic load, is linked to an increased risk of dementia. Fostering brain resilience through physical exercise can counteract allostatic load and improve adaptation to age-related brain alterations. Fibronectin type III domain-containing protein 5 (FNDC5)/irisin is a neuroprotective exercise-linked hormone found in extracellular vesicles (EV-FNDC5/irisin). Here, we sought to analyse EV-FNDC5/irisin in ageing as a promising biomarker of brain resilience. We measured exercise-associated factors, including EV-FNDC5/irisin, brain-derived neurotrophic factor (BDNF), and cathepsin B in the serum of 31 young (18-28 years) and 19 older subjects (65-79 years). Levels of FNDC5/irisin in serum-derived EVs are markedly reduced in older subjects compared to young ( Show less

PTB (PhosphoTyrosine Binding) domains are protein domains that exert their function by binding phosphotyrosine residues on other proteins. They are commonly found in a variety of signaling proteins and are important for mediating protein-protein interactions in numerous cellular processes. PTB domains can also exhibit binding to unphosphorylated ligands, suggesting that they have additional binding specificities beyond phosphotyrosine recognition. Structural studies have reported that the PTB domain from FRS2 possesses this peculiar feature, allowing it to interact with both phosphorylated and unphosphorylated ligands, such as TrkB and FGFR1, through different topologies and orientations. In an effort to elucidate the dynamic and functional properties of these protein-protein interactions, we provide a complete characterization of the folding mechanism of the PTB domain of FRS2 and the binding process to peptides mimicking specific regions of TrkB and FGFR1. By analyzing the equilibrium and kinetics of PTB folding, we propose a mechanism implying the presence of an intermediate along the folding pathway. Kinetic binding experiments performed at different ionic strengths highlighted the electrostatic nature of the interaction with both peptides. The specific role of single amino acids in early and late events of binding was pinpointed by site-directed mutagenesis. These results are discussed in light of previous experimental works on these protein systems. Show less

A role for inflammation and oxidative stress is reported in autism spectrum disorders (ASDs). Here, we tested possible changes in expression and/or oxidative status for plasma proteins in subjects with ASDs. To evaluate protein expression and protein adducts of lipid peroxidation-derived aldehyde, analysis of plasma proteins was performed in 30 subjects with ASDs and compared with 30 healthy controls with typical development, using a proteomic approach. Significant changes were evidenced for a total of 12 proteins. Of these, ten were identified as proteins involved in the acute inflammatory response including alpha-2-macroglobulin, alpha-1-antitrypsin, haptoglobin, fibrinogen, serum transferrin, prealbumin, apolipoprotein A-I apolipoprotein A-IV, apolipoprotein J, and serum albumin. In addition, significant changes occurred for two immunoglobulins alpha and gamma chains. Our present data indicate that an inflammatory response, coupled with increased lipid peroxidation, is present in subjects with ASDs. This information can provide new insight into the identification of potential plasma protein biomarkers in autism. Show less