Intrathecal Injection of Scorpion Venom Peptide, BmK AGAP Inhibits KCNQ2/3, TRPV1 and Decreases TNF-α and IL-1β Expression to Attenuates Pain in Rat

Abstract

The current study was designed to test the hypothesis that Recombinant Buthus martensii Kasch Analgesic-Antitumor Peptide (rBmK AGAP) potentiates lidocaine induced analgesia. The chronic constrictive injury was performed on 72 rats to induce a rapid onset and long-lasting pain. The rats were randomly assigned to one of six groups; Group A (n=12) received an intrathecal injection of saline, Group B (n=12) received an intrathecal injection of lidocaine alone, Group C (n=12) received an intrathecal injection of rBmK AGAP alone, Group D, E, and F (n=12 each) received an intrathecal injection of lidocaine + rBmK AGAP (0.5, 1, or 2 mg.kg^-1). The von Frey filaments were used to assessed mechanical allodynia. Nav1.7 and TRPV1 currents were recorded by whole-cell aspiration patch-clamp technique, and KCNQ2/3 currents were recorded by whole-cell drilling patch-clamp technique. We performed qPCR, ELISA and western blot to determine the expression of TNF-α, IL-1β, IL-6, IL-10, p65/NF-κB, p-p65/NF-κB, IKKα, IκBα in rats following rBmK AGAP treatment. The rats from the lidocaine + BmK AGAP group exhibited significantly increased Paw Withdrawal Threshold (PWT) after 30 minutes of drug administration which gradually decreased to baseline PWT at 360 minutes. The whole-cell aspiration patch-clamp technique showed that rBmK AGAP significantly inhibited KCNQ2/3 and TRPV1 currents to potentiate lidocaine induced analgesia. We observed significantly decreased expression of TNF-α and IL-1β following the combined treatment compared with lidocaine or rBmK AGAP alone. Intrathecal injection of rBmK AGAP inhibits KCNQ2/3, TRPV1 and decreases pro-inflammatory cytokines, TNF-α, and IL-1β expression and potentiates lidocaine induced analgesia.

Funding Statement: This study was supported by the Key Laboratory of Liaoning Provincial Education Department (Grant NO: LZ2016002) and Liaoning Natural Science Foundation (Grant NO: 20170540290).

Declaration of Interests: All authors declared no conflict of interests.

Ethics Approval Statement: The animal ethics committee of the Dalian Medical University approved all the study protocols and were by the declaration of the national institutes of health guide for the care and use of laboratory animals.