Aplysia kurodai-derived glycosaminoglycans increase the phagocytic ability of macrophages via the activation of AMP-activated protein kinase and cytoskeletal reorganization in RAW264.7 cells

Glycosaminoglycans (GAGs) control a variety of physiological processes, but the roles of GAGs in inflammatory processes are unclear. Compared to mammals, sea hares are safer and good materials for massive production of GAG. This study was performed to identify the role of GAG isolated from the sea hare Aplysia kurodai (A. kurodai) in macrophage phagocytosis. Treatment with GAG activated macrophage RAW264.7 cells and increased the phagocytic ability. The GAG-induced activation and phagocytosis of macrophages were reduced with compound C, an inhibitor of AMP-activated protein kinase (AMPK). Compound C primarily inhibited cellular spreading. In addition, disruption of cytoskeletal reorganization with nocodazole and cytochalasin D reduced the GAG-activated phagocytic ability, cellular spreading, and vacuolization of RAW264.7 cells. These results indicate that GAG increases the phagocytic ability of macrophages via AMPK activation and cytoskeletal reorganization. Our results suggest that A. kurodai-derived GAG may have potential therapeutic agent with immunostimulatory activity.