Modelo animal de esclerose múltipla : efeitos benéficos da CTK 01512-2, uma versão recombinante da toxina Phα1β isolada da aranha Phoneutria nigriventer

Abstract

Voltage-gated calcium channels (VGCC) play a critical role in neuroinflammatory diseases, such as multiple sclerosis (MS). We investigated the effects of the recombinant peptide CTK 01512-2, an inhibitor of N-type VGCC/TRPA1-mediated calcium influx, in the mouse model of experimental autoimmune encephalomyelitis (EAE). The effects of this molecule were compared to those displayed by ziconotide - a selective N-type VGCC blocker clinically used for chronic pain, and fingolimod - an orally active drug employed for MS treatment. The intrathecal (i.t.) administration of CTK 01512-2 markedly prevented hyperalgesia, body weight loss, splenomegaly, MS-like clinical and neurological scores, impaired motor coordination and spatial memory, with an efficacy comparable to that observed for ziconotide and fingolimod. This molecule displayed a favourable profile on EAE-induced neuroinflammatory changes, including inflammatory infiltrate, demyelination, increased pro-inflammatory cytokines, glial activation and glucose hypermetabolism in brain and spinal cord. The recovery of spatial memory, besides a reduction of serum leptin levels, allied to central and peripheral elevation of the anti-inflammatory cytokine IL-10, were solely modulated by CTK 01512-2, dosed intrathecally. The systemic i.v. administration of CTK 01512-2 also reduced the EAE-elicited MS-like symptoms and signals, similarly to that seen in animals that received fingolimod orally. Ziconotide lacked any significant effect when dosed by i.v. route. Collectively, these results indicate that CTK 01512-2 greatly improved the neuroinflammatory responses in a mouse model of MS, with a higher efficacy when compared to ziconotide, pointing out this molecule as a promising adjuvant for MS management.