F-53B disrupts energy metabolism by inhibiting the V-ATPase-AMPK axis in neuronal cells

Abstract

6:2 chloro-polyfluorooctane ether sulfonate (F-53B) is considered neurotoxic, but its mechanisms remain unclear. This study aimed to investigate the toxic effects of F-53B on neuronal cells, focusing on the role of the V-ATPase-AMPK axis in the mechanism of abnormal energy metabolism. Mouse astrocytes (C8-D1A) and human neuroblastoma cells (SH-SY5Y) exposed to F-53B were used as in vitro models. Our findings demonstrated that F-53B inhibited the expression of V-ATPase B2 and reduced V-ATPase activity, leading to an increase in lysosomal pH, decreased expression of TRPML1, and lysosomal Ca^2 + accumulation. In turn, led to reduced the expression of CaMKK2 and phosphorylated AMPK (p-AMPK). Ultimately, mitochondria were damaged, evidenced by increased mitochondrial reactive oxygen species, mitochondrial membrane potential, and impaired mitochondrial oxidative phosphorylation, as shown by reduced NDUFS1 expression and diminished respiratory chain complex I activity. F-53B reduced the expression of the key glycolytic protein PFKFB3. Notably, V-ATPase B2 overexpression indirectly activates AMPK. Furthermore, resveratrol, an AMPK agonist, alleviates mitochondrial dysfunction and increases ATP production by promoting the recovery of mitochondria and glycolytic pathways. These findings elucidate a novel mechanism by which F-53B induces neurotoxicity through the V-ATPase-AMPK axis, and indicate V-ATPase and AMPK as potential therapeutic targets.