Schwann cell TRPA1 mediates neuroinflammation that sustains macrophage-dependent neuropathic pain in mice

作者：Francesco De Logu, Romina Nassini, Serena Materazzi, Muryel Carvalho Gonçalves, Daniele Nosi, Duccio Rossi Degl’Innocenti, Ilaria M. Marone, Juliano Ferreira, Simone Li Puma, Silvia Benemei, Gabriela Trevisan, Daniel Souza Monteiro de Araújo, Riccardo Patacchini, Nigel W. Bunnett, Pierangelo Geppetti · 发表于：Nature Communications · 年份：2017 · DOI：10.1038/s41467-017-01739-2 · 被引用次数：306 · 研究领域：Ion Channels and Receptors、Pain Mechanisms and Treatments、Neuropeptides and Animal Physiology

Abstract It is known that transient receptor potential ankyrin 1 (TRPA1) channels, expressed by nociceptors, contribute to neuropathic pain. Here we show that TRPA1 is also expressed in Schwann cells. We found that in mice with partial sciatic nerve ligation, TRPA1 silencing in nociceptors attenuated mechanical allodynia, without affecting macrophage infiltration and oxidative stress, whereas TRPA1 silencing in Schwann cells reduced both allodynia and neuroinflammation. Activation of Schwann cell TRPA1 evoked NADPH oxidase 1 (NOX1)-dependent H 2 O 2 release, and silencing or blocking Schwann cell NOX1 attenuated nerve injury-induced macrophage infiltration, oxidative stress and allodynia. Furthermore, the NOX2-dependent oxidative burst, produced by macrophages recruited to the perineural space activated the TRPA1–NOX1 pathway in Schwann cells, but not TRPA1 in nociceptors. Schwann cell TRPA1 generates a spatially constrained gradient of oxidative stress, which maintains macrophage infiltration to the injured nerve, and sends paracrine signals to activate TRPA1 of ensheathed nociceptors to sustain mechanical allodynia.