Environmental Regulation, Molecular Profiling, and Preliminary Functional Evaluation of Extracellular Vesicles from...

Extracellular vesicles (EVs) from the edible mushroom Pleurotus tuber-regium (PTR) were investigated with respect to their environmental responsiveness, molecular features, and preliminary functional properties. PTR-EVs were characterized by dynamic light scattering, nanoparticle tracking analysis, and transmission electron microscopy. Proteomic analysis revealed enrichment of ribosomal and proteasomal proteins, redox-related enzymes, and vesicle trafficking components, suggesting non-random molecular representation. Small RNA sequencing identified abundant novel miRNAs with predicted targets involved in nitrogen metabolism, cell wall remodeling, redox regulation, and ubiquitin-mediated proteolysis. Among the tested factors, temperature showed the strongest association with vesicle production, with particle concentration increasing from 1.22 × 10⁹ to 7.31 × 10⁹ particles/mL at 34 °C, approximately six-fold higher than at 30 °C. Transcriptomic profiling showed coordinated repression of cell wall-associated genes and redox enzymes, together with induction of endoplasmic reticulum proteostasis pathways, consistent with stress-associated changes in the cellular context of vesicle release. Ultrasonicated PTR-EVs exhibited enhanced DPPH and ABTS radical-scavenging activities in chemical assays, with DPPH increasing from 59.52% to 71.73% and ABTS from 38.25% to 40.51%. Encapsulation efficiencies reached 32.67% ± 1.3% for proanthocyanidins and 46.01% ± 0.5% for curcumin. PTR-EVs showed the best short-term stability at pH 7 and 4 °C, supporting their further evaluation as an edible fungal vesicle platform for food-related nanoscale delivery.