Department of Anesthesiology, The Second Affiliated Hospital of Zhengzhou University, Henan, China.
Department of Human Anatomy, School of Basic Medicine, Zhengzhou University, Henan, China.
J Cell Biochem. 2020 Jan;121(1):768-778. doi: 10.1002/jcb.29322. Epub 2019 Aug 5.
Previous studies have found that increased expression of Nav1.9 and protein kinase C (PKC) contributes to pain hypersensitivity in a couple of inflammatory pain models. Here we want to observe if PKC can regulate the expression of Nav1.9 in dorsal root ganglion (DRG) in rheumatoid arthritis (RA) pain model. A chronic knee joint inflammation model was produced by intra-articular injection of the complete Freund's adjuvant (CFA) in rats. Nociceptive behaviors including mechanical, cold, and heat hyperalgesia were examined. The expression of Nav1.9 and PKCα in DRG was detected by a quantitative polymerase chain reaction, Western blot, and immunofluorescence. The in vitro and in vivo effects of a PKC activator (phorbol 12-myristate 13-acetate [PMA]) and a PKC inhibitor (GF-109203X) on the expression of Nav1.9 were examined. Moreover, the effects of PKC modulators on nociceptive behaviors were studied. Increased mechanical, heat, and cold sensitivity was observed 3 to 14 days after CFA injection. Parallel increases in messenger RNA and protein expression of Nav1.9 and PKCα were found. Immunofluorescence experiments found that Nav1.9 was preferentially colocalized with IB4+DRG neurons in RA rats. In cultured DRG neurons, PMA increased Nav1.9 expression while GF-109203X prevented the effect of PMA. PMA increased Nav1.9 expression in naïve rats while GF-109203X decreased Nav1.9 expression in RA rats. In naïve rats, PMA caused mechanical and cold hyperalgesia. On the other hand, GF-109203X attenuated mechanical and cold hyperalgesia in RA-pain model. Nav1.9 might be upregulated by PKCα in DRG, which contributes to pain hypersensitivity in CFA-induced chronic knee joint inflammation model of RA pain.
先前的研究发现，Nav1.9 和蛋白激酶 C（PKC）的表达增加导致几种炎症性疼痛模型中的痛觉过敏。在这里，我们想要观察 PKC 是否可以调节类风湿关节炎（RA）疼痛模型中背根神经节（DRG）中 Nav1.9 的表达。通过向大鼠关节内注射完全弗氏佐剂（CFA）来产生慢性膝关节炎症模型。通过机械、冷和热痛觉超敏反应来检查伤害感受行为。通过定量聚合酶链反应、Western blot 和免疫荧光检测 DRG 中 Nav1.9 和 PKCα 的表达。通过 PKC 激活剂（佛波醇 12-肉豆蔻酸 13-醋酸酯[PMA]）和 PKC 抑制剂（GF-109203X）在体外和体内检查对 Nav1.9 表达的影响。此外，还研究了 PKC 调节剂对伤害感受行为的影响。在 CFA 注射后 3 至 14 天观察到机械、热和冷敏感性增加。发现 Nav1.9 的信使 RNA 和蛋白质表达均平行增加。免疫荧光实验发现 Nav1.9 优先与 RA 大鼠的 IB4+DRG 神经元共定位。在培养的 DRG 神经元中，PMA 增加了 Nav1.9 的表达，而 GF-109203X 则阻止了 PMA 的作用。PMA 增加了幼稚大鼠中 Nav1.9 的表达，而 GF-109203X 则降低了 RA 大鼠中 Nav1.9 的表达。在幼稚大鼠中，PMA 引起机械和冷痛觉过敏。另一方面，GF-109203X 减轻了 RA 疼痛模型中的机械和冷痛觉过敏。PKCα 在 DRG 中可能上调 Nav1.9，导致 CFA 诱导的慢性膝关节炎症模型中的 RA 疼痛中的痛觉过敏。
