Transient receptor potential canonical 5 (TRPC5) mediates inflammatory mechanical pain

Abstract

Persistent tactile pain is a poorly managed symptom of inflammatory and neuropathic injury. To develop therapies for this maladaptive sensation, the underlying molecular mediators must be identified. Using knockout mice and pharmacological inhibitors, we identified transient receptor canonical 5 (TRPC5) as a key contributor to the persistent tactile pain that occurs in many inflammatory and neuropathic preclinical rodent models. TRPC5 inhibition was effective in injuries associated with elevated levels of the bioactive phospholipid lysophosphatidylcholine (LPC). Exogenous application of LPC induced TRPC5-dependent behavioral mechanical allodynia, neuronal mechanical hypersensitivity, and spontaneous pain. In vitro, LPC activated both homomeric mouse and human TRPC5 channels, which upon examination of human dorsal root ganglia tissue, were expressed in 75% of human sensory neurons. Based on these results, TRPC5 inhibitors should be pursued as personalized therapy for spontaneous and tactile pain in conditions where elevated LPC is a biomarker.

ASIC3-dependent spinal cord nociceptive signaling in cutaneous pain induced by lysophosphatidyl-choline

“…However, LPC not only modulates ASIC3 (Marra et al, 2016), but has also been reported to affect other pain-related channels including TREK1 (Maingret et al, 2000), TRPM8 (Andersson et al, 2007;Gentry et al, 2010), TRPC5 (Flemming et al, 2006;Sadler et al, 2020), and more recently TRPV1 (Rimola et al, 2020). Our data demonstrate an overall excitatory effect of peripheral injection of the lysolipid on spinal neurons and confirm the excitatory nature of LPC.…”