INFLUENCE OF GALACTOSAMINOGALACTAN ON NEUTROPHIL ACTIVATION AND ATHLETIC INFLAMMATION: INSIGHTS INTO THE TNF-Α-NF-ΚB PATHWAY

Abstract

Purpose: This study investigates the role of Galactosaminogalactan (GAG), derived from Aspergillus fumigatus, in inducing reactive oxygen species (ROS) in neutrophils and explores the involvement of the TNF-α-NF-κB pathway, with implications for understanding inflammatory responses in athletes. Materials and Methods: Neutrophils were isolated from the peripheral blood of healthy donors and exposed to GAG. ROS levels, both intracellular and extracellular, along with inflammatory mediators such as IL-1β, LTB4, CXCL1, TNF-α, and NF-κB, were quantified. Treatments included a NADPH oxidase inhibitor, Diphenyleneiodonium chloride (DPI), and a TNF-α inhibitor, Etanercept (ETN), to dissect the pathway involved in ROS production initiated by GAG. Results: GAG exposure significantly increased both intracellular and extracellular ROS production (p<0.05). Inhibition of NADPH oxidase with DPI effectively blocked extracellular ROS generation (p<0.05), while TNF-α inhibition with ETN impeded both intracellular and extracellular ROS production. Additionally, GAG-induced TNF-α expression was suppressed by DPI (p<0.05). NF-κB expression, stimulated by GAG, was also reduced by ETN (p<0.05), indicating its role downstream of TNF-α in this pathway. Notably, GAG did not significantly affect IL-1β and LTB4 levels but increased CXCL1 (p<0.05), which was reduced upon ETN treatment. Conclusions: GAG activates neutrophil NADPH oxidase to generate ROS through the TNF-α-NF-κB signaling pathway. This activation process suggests that managing TNF-α levels might mitigate ROS-induced damage and potentially reduce neutrophil apoptosis. For athletes, understanding how to modulate these inflammatory responses could be crucial in managing stress and inflammation related to intense physical activities, enhancing recovery, and maintaining optimal performance.