Open AccessSensitization of knee-innervating sensory neurons by tumor necrosis factor-α-activated fibroblast-like synoviocytes: an in vitro, coculture model of inflammatory pain
Author(s) -
Sampurna Chakrabarti,
Zoe Hore,
Luke A. Pattison,
Sylvine Lalnunhlimi,
Charity N. Bhebhe,
Gerard Callejo,
D Bulmer,
Leonie S. Taams,
Franziska Denk,
Ewan St. John Smith
Publication year - 2020
Publication title -
pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.524
H-Index - 258
eISSN - 1872-6623
pISSN - 0304-3959
DOI - 10.1097/j.pain.0000000000001890
Subject(s) - proinflammatory cytokine , sensitization , tumor necrosis factor alpha , dorsal root ganglion , arthritis , medicine , inflammation , stimulation , nociceptor , rheumatoid arthritis , sensory neuron , chronic pain , immunology , neuroscience , cancer research , nociception , biology , central nervous system , receptor , anatomy , dorsum , psychiatry
Pain is a principal contributor to the global burden of arthritis with peripheral sensitization being a major cause of arthritis-related pain. Within the knee joint, distal endings of dorsal root ganglion neurons (knee neurons) interact with fibroblast-like synoviocytes (FLS) and the inflammatory mediators they secrete, which are thought to promote peripheral sensitization. Correspondingly, RNA sequencing has demonstrated detectable levels of proinflammatory genes in FLS derived from arthritis patients. This study confirms that stimulation with tumor necrosis factor (TNF-α) results in expression of proinflammatory genes in mouse and human FLS (derived from osteoarthritis and rheumatoid arthritis patients), as well as increased secretion of cytokines from mouse TNF-α-stimulated FLS (TNF-FLS). Electrophysiological recordings from retrograde labelled knee neurons cocultured with TNF-FLS, or supernatant derived from TNF-FLS, revealed a depolarized resting membrane potential, increased spontaneous action potential firing, and enhanced TRPV1 function, all consistent with a role for FLS in mediating the sensitization of pain-sensing nerves in arthritis. Therefore, data from this study demonstrate the ability of FLS activated by TNF-α to promote neuronal sensitization, results that highlight the importance of both nonneuronal and neuronal cells to the development of pain in arthritis.