PROLONGED RESVERATROL TREATMENT MODIFIES MORPHOLOGY AND ADENOSINE RECEPTORS IN SH-SY5Y CELLS

Resveratrol (RSV), a natural polyphenol, exhibits potent antioxidant, neuroprotective, and antitumoral properties. We previously demonstrated that treatment with 200 μM RSV for 24h enhances A₁ receptor (A₁R) signaling while diminishing A_2AR receptor (A_2AR) functionality, leading to an apparent reduction in cAMP signaling as a mechanism of antitumoral action in neuroblastoma cells. However, the effects of prolonged RSV exposure on adenosinergic signaling architecture and cellular phenotype remain unknown. This study aimed to investigate how sustained RSV treatment affects cell viability, adenosine receptor membrane localization, and morphological phenotype in human neuroblastoma SH-SY5Y cells. Cells were treated with 10 and 100 µM RSV for extended periods (24, 48, and 72 hours). Cell viability was assessed by XTT assay, A₁R abundance at the plasma membrane was quantified by Western blotting, and morphological changes were evaluated through phase-contrast microscopy, cell segmentation, and morphometric analysis. Prolonged RSV treatment sustained reduction in cell viability consistent with cytostatic activity. Notably, A₁R level at the plasma membrane significantly decreased despite previous evidence of A₁R upregulation during acute exposure, suggesting adaptive desensitization or receptor internalization during chronic treatment. Concomitantly, RSV induced morphological remodeling characterized by elongated, branched phenotypes resembling neuronal differentiation. The transition from acute A₁R enhancement to chronic A₁R membrane reduction, coupled with morphological changes toward neuronal-like phenotypes, indicates dynamic remodeling of adenosinergic signaling during sustained RSV exposure. These findings suggest that prolonged RSV treatment engages adaptive mechanisms potentially involving receptor levels modulation and differentiation-associated receptor trafficking, reinforcing RSV's multifaceted neuroprotective and anti-proliferative potential in neurodegeneration and cancer models.