Sensitization of TRPV1 by protein kinase C in rats with mono-iodoacetate-induced joint pain
Sensitization of TRPV1 by protein kinase C in rats with mono-iodoacetate-induced joint pain
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DOI：
10.1016/j.joca.2016.02.010
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发表时间：
2016-07-01
影响因子：
7
通讯作者：
Morioka, Y.
中科院分区：
文献类型：
--
作者：
Koda, K.;Hyakkoku, K.;Morioka, Y.
目的：目的：观察瞬时受体电位香草酸1（TRPV 1）受体在单碘乙酸（MIA）诱导的大鼠关节痛模型中的功能变化，并探讨其作用机制（MIA大鼠），其具有类似于骨关节炎的关节退化和软骨损失。通过在MIA大鼠膝关节注射辣椒素诱导的短暂自发痛行为和电生理变化来评估TRPV 1在MIA大鼠中的增敏作用。背根神经节（DRG）神经元支配膝关节对辣椒素的反应。TRPV 1致敏的机制进行了分析，通过一种新开发的夹心酶联免疫吸附试验，检测磷酸化的TRPV 1，然后在体内和体外的蛋白激酶C（PKC）的功能和表达分析，其中涉及TRPV 1的磷酸化。此外，辣椒素的敏感性，辣椒素诱导的内向电流，在MIA大鼠DRG神经元显着增加。TRPV 1蛋白水平保持不变，但磷酸化TRPV 1在Ser 800增加在DRG神经元的MIA大鼠。磷酸化蛋白激酶C 3（p-PKC 3）在MIA大鼠DRG神经元中表达增加，并与TRPV 1共定位。关节内给予PKC抑制剂双吲哚马来酰亚胺I可抑制辣椒素诱导的MIA大鼠疼痛相关行为。此外，关节内注射PKC激活剂佛波醇12-肉豆蔻酸酯13-乙酸酯可增加正常大鼠辣椒素诱导的痛相关行为。结论：TRPV 1通过PKC激活致敏MIA大鼠膝关节和DRG神经元。因此，TRPV 1敏化可能参与骨关节炎引起的慢性疼痛。(C)2016国际骨关节炎研究学会。由爱思唯尔有限公司出版。保留所有权利。
Objective: To assess the functional changes of Transient receptor potential vanilloid 1 (TRPV1) receptor and to clarify its mechanism in a rat mono-iodoacetate (MIA)-induced joint pain model (MIA rats), which has joint degeneration with cartilage loss similar to osteoarthritis.Methods: Sensitization of TRPV1 in MIA rats was assessed by transient spontaneous pain behavior induced by capsaicin injection in knee joints and electrophysiological changes of dorsal root ganglion (DRG) neurons innervating knee joints in response to capsaicin. Mechanisms of TRPV1 sensitization were analyzed by a newly developed sandwich enzyme-linked immunosorbent assay that detects phosphorylated TRPV1, followed by functional and expression analyses of protein kinase C (PKC) in vivo and in vitro, which involves TRPV1 phosphorylation.Results: Pain-related behavior induced by intra-articular injection of capsaicin was significantly increased in MIA rats compared with sham rats. In addition, capsaicin sensitivity, evaluated by capsaicin-induced inward currents, was significantly increased in DRG neurons of MIA rats. Protein levels of TRPV1 remained unchanged, but phosphorylated TRPV1 at Ser800 increased in DRG neurons of MIA rats. Phosphorylated-PKC 3 (p-PKC 3) increased and co-localized with TRPV1 in DRG neurons of MIA rats. Capsaicin-induced pain-related behavior in MIA rats was inhibited by intra-articular pretreatment of the PKC inhibitor bisindolylmaleimide I. In addition, intra-articular injection of the PKC activator phorbol 12-myristate 13-acetate increased capsaicin-induced pain-related behavior in normal rats.Conclusion: TRPV1 was sensitized at the knee joint and at DRG neurons of MIA rats through PKC activation. Thus, TRPV1 sensitization might be involved in chronic pain caused by osteoarthritis. (C) 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.