ABSTRACT
Background Several studies have shown that scorpion venom peptide BmK AGAP has an analgesic activity. Our previous study also demonstrated that intraplantar injection of BmK AGAP ameliorates formalin-induced spontaneous nociceptive behavior. However, the effect of intrathecal injection of BmK AGAP on nociceptive processing is poorly understood. Methods We investigated the effects of intrathecal injection of BmK AGAP on spinal nociceptive processing induced by chronic constrictive injury or formalin. Thermal hyperalgesia and mechanical allodynia were measured using radiant heat and the von Frey filaments test. Formalin-induced spontaneous nociceptive behavior was also investigated. C-Fos expression was assessed by immunohistochemistry. Phosphorylated mitogen-activated protein kinase (p-MAPK) expression was monitored by Western blot assay. Results Intrathecal injection of BmK AGAP reduced chronic constrictive injury-induced neuropathic pain behavior and pain from formalin-induced inflammation, accompanied by decreased expression of spinal p-MAPKs and c-Fos protein. The results of combining low doses of different MAPK inhibitor (U0126, SP600125, or SB203580; 0.1 µg for each inhibitor) with a low dose of BmK AGAP (0.2 µg) suggested that BmK AGAP could potentiate the effects of MAPK inhibitors on inflammation-associated pain. Conclusion Our results demonstrate that intrathecal injection of BmK AGAP produces a sensory-specific analgesic effect via a p-MAPK-dependent mechanism.
Subject(s)
Analgesics/therapeutic use , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Scorpion Venoms/therapeutic use , Sensation , Spinal Cord/enzymology , Analgesics/pharmacology , Animals , Constriction , Disease Models, Animal , Down-Regulation/drug effects , Formaldehyde , Hyperalgesia/complications , Hyperalgesia/drug therapy , Hyperalgesia/pathology , Inflammation/complications , Inflammation/drug therapy , Inflammation/pathology , Injections, Spinal , Male , Mice , Mitogen-Activated Protein Kinases/metabolism , Neuralgia/complications , Neuralgia/drug therapy , Neuralgia/pathology , Phosphorylation/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins c-fos/metabolism , Scorpion Venoms/administration & dosage , Scorpion Venoms/pharmacology , Sensation/drug effects , Spinal Cord/drug effects , Spinal Cord/pathologyABSTRACT
To investigate the effects of human anti-BAFF scFv-Fc against the hsBAFF, ICR mice were randomly divided into six groups: control, hsBAFF (1 mg x kg(-1)), hsBAFF (1 mg x kg(-1)) + Ab (1 mg x kg(-1)), hsBAFF (1 mg x kg(-1)) + Ab (2 mg x kg(-1)), hsBAFF (1 mg x kg(-1)) + human IgG (1 mg x kg(-1)) and hsBAFF (1 mg x kg(-1)) + human IgG (2 mg x kg(-1)) groups. The effects of scFv-Fc administration on the proliferation of B lymphocytes were evaluated using an MTT assay. The titres of antibody in the serum and B lymphocytes differentiation were assessed by ELISA and flow cytometry, respectively. The results showed that administration of scFv-Fc to mice injected with hsBAFF significantly prevented human BAFF-induced increases in splenic B cell numbers and serum immunoglobulin levels. Furthermore, this fully human antibody would avoid inducing the human anti-mouse antibody (HAMA) response when used in humans. These findings suggest that the compact antibody may be useful in therapeutic or diagnostic application of the BAFF-associated autoimmune diseases in human.
