title: Interleukin-6-mediated functional upregulation of TRPV1 receptors in dorsal root ganglion neurons through the activation of JAK/PI3K signaling pathway: roles in the development of bone cancer pain in a rat model.
abstract: Primary and metastatic cancers that affect bone are frequently associated with severe and intractable pain. The mechanisms underlying the pathogenesis of bone cancer pain still remain largely unknown. Previously, we have reported that sensitization of primary sensory dorsal root ganglion (DRG) neurons contributes to the pathogenesis of bone cancer pain in rats. In addition, numerous preclinical and clinical studies have revealed the pathological roles of interleukin-6 (IL-6) in inflammatory and neuropathic hyperalgesia. In this study, we investigated the role and the underlying mechanisms of IL-6 in the development of bone cancer pain using in vitro and in vivo approaches. We first demonstrated that elevated IL-6 in DRG neurons plays a vital role in the development of nociceptor sensitization and bone cancer-induced pain in a rat model through IL-6/soluble IL-6 receptor (sIL-6R) trans-signaling. Moreover, we revealed that functional upregulation of transient receptor potential vanilloid channel type 1 (TRPV1) in DRG neurons through the activation of Janus kinase (JAK)/phosphatidylinositol 3-kinase (PI3K) signaling pathway contributes to the effects of IL-6 on the pathogenesis of bone cancer pain. Therefore, suppression of functional upregulation of TRPV1 in DRG neurons by the inhibition of JAK/PI3K pathway, either before surgery or after surgery, reduces the hyperexcitability of DRG neurons and pain hyperalgesia in bone cancer rats. We here disclose a novel intracellular pathway, the IL-6/JAK/PI3K/TRPV1 signaling cascade, which may underlie the development of peripheral sensitization and bone cancer-induced pain.
authors.affiliation: Neuroscience Research Institute, Peking University, Beijing, China Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, China Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Beijing, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Fang
authors.forename: Ling-Yu
authors.initials: LY
authors.lastname: Kong
authors.forename: Jie
authors.initials: J
authors.lastname: Cai
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Liu
authors.forename: Ji-Sheng
authors.initials: JS
authors.lastname: Han
authors.forename: Guo-Gang
authors.initials: GG
authors.lastname: Xing
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001859:Bone Neoplasms / Q000150:complications*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006930:Hyperalgesia / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D053612:Janus Kinases / Q000378:metabolism*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010146:Pain / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D017288:Pain Threshold / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019947:Receptors, Interleukin-6 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology*
chemical_list: D004791:Enzyme Inhibitors; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D053612:Janus Kinases