Effects Of Aerobic Training On Pentraxin 3/Toll-like Receptor 4 And Oxidative Status In Elderly Adults

Abstract

PURPOSE: The consequence of reactive oxygen and nitrogen species (ROS/RNS)-mediated cellular aging has been linked to various diseases, such as atherothrombosis and cancer. One of the possible mechanisms for these ROS-mediated diseases is through the activation of intracellular pattern recognition receptors (PRR), thereby contributing to a chronic low-grade pro-inflammatory systemic state in aging. Pentraxin 3 (PTX3) is a soluble PRR mainly released from endothelial cells and immunes cells and utilizes its counter-regulatory function in promoting the anti-inflammatory response via the inhibition of toll-like receptor 4 (TLR4). Although increased level of PTX3 has been shown following stimulation of oxidative stress and is also associated with aging-related diseases, the relationship between PTX3 and oxidative stress in aging remains to be elucidated. However, exercise has been proposed as the key intervention for the maintenance of health in the elderly. Therefore, this study was to examine whether or not the level of PTX3 on TLR4-dependent inflammation would be associated with changes in oxidative stress in both plasma and peripheral blood mononuclear cells (PBMCs) following 8 weeks of aerobic training in the elderly. METHODS: Fourteen elderly subjects (9 trained and 5 controls) were recruited to participate in an 8-week aerobic training. The ELISA and western blot analyses were used to determine the levels of PTX3 and biomarkers of oxidative stress in both plasma and PBMCs prior to and following training. RESULTS: No changes in plasma levels of PTX3 and oxidative stress markers (GSH, TEAC, and ROS/RNS) were observed in trained vs. control groups. However, our analyses showed a downregulation of PTX3 expression in PBMCs (P = 0.017) following aerobic training, along with decreased ratio of PTX3/TLR4 (P = 0.047). Furthermore, the tendency of oxidative stress response in PBMCs remained unchanged as shown in plasma levels. Finally, no correlation was observed between PTX3 and any oxidative stress biomarkers following training protocol. CONCLUSIONS: These findings demonstrate the downregulation of PTX3 and PTX3/TLR4 ratio in PBMCs of elderly subjects, irrespective of changes in oxidative stress following 8 weeks of aerobic training.