Abstract

Beyond their pivotal role in hemostasis and thrombosis, the function of platelets in inflammation and immune regulation is increasingly recognized. 8-oxo-7,8-dihydroguanosine (8-oxo-Guo) is an endogenous nucleic acid oxidation product. Unclear is whether 8-oxo-Guo possesses the capacity to modulate the inflammatory status of circulating blood and platelet function. The present study investigated the influence of 8-oxo-Guo on platelet activation responses. An intravenous injection of 8-oxo-Guo in C57BL/6J mice enhanced platelet activity and increased levels of plasma inflammatory factors. To elucidate the underlying mechanism, human purified platelets were used. The results showed that 8-oxo-Guo treatment increased the expression of Toll-like receptor 2 (TLR2) and TLR4 on platelets. Integrated proteomic and phosphoproteomic analysis, combined with Western blot, demonstrated that 8-oxo-Guo activated multiple inflammation-related signaling pathways, including TLR2/TLR4–MyD88-associated signaling. Surface plasmon resonance analysis further demonstrated direct interactions between 8-oxo-Guo and TLR4/TLR2 with micromolar-range affinities, and pharmacological inhibition of TLR2 or TLR4 attenuated 8-oxo-Guo-induced inflammatory signaling. Consistent results were obtained from both in vivo and in vitro experiments. Our findings suggest that 8-oxo-Guo promotes platelet inflammatory activation at least partly through TLR2/TLR4-associated signaling, thereby expanding our understanding of platelet functions in oxidative stress-related immune regulation and identifying a potential therapeutic target for inflammatory diseases.