Cold sensitivity of TRPA1 is unveiled by the prolyl hydroxylation blockade-induced sensitization to ROS.

Takahito Miyake,Kanako So,Keisuke Inoue,Takayuki Nakagawa,Hisashi Shirakawa,Meng Zhao,Saki Nakamura,Nobuaki Takahashi,Yasuo Mori,Shuji Kaneko,Tomohiro Numata

doi:10.1038/ncomms12840

Abstract

Mammalian transient receptor potential ankyrin 1 (TRPA1) is a polymodal nociceptor that plays an important role in pain generation, but its role as a cold nociceptor is still controversial. Here, we propose that TRPA1 can sense noxious cold via transduction of reactive oxygen species (ROS) signalling. We show that inhibiting hydroxylation of a proline residue within the N-terminal ankyrin repeat of human TRPA1 by mutation or using a prolyl hydroxylase (PHD) inhibitor potentiates the cold sensitivity of TRPA1 in the presence of hydrogen peroxide. Inhibiting PHD in mice triggers mouse TRPA1 sensitization sufficiently to sense cold-evoked ROS, which causes cold hypersensitivity. Furthermore, this phenomenon underlies the acute cold hypersensitivity induced by the chemotherapeutic agent oxaliplatin or its metabolite oxalate. Thus, our findings provide evidence that blocking prolyl hydroxylation reveals TRPA1 sensitization to ROS, which enables TRPA1 to convert ROS signalling into cold sensitivity.

Highlights

Mammalian transient receptor potential ankyrin 1 (TRPA1) is a polymodal nociceptor that plays an important role in pain generation, but its role as a cold nociceptor is still controversial
We previously reported another mechanism for TRPA1 activation: hypoxia inhibits prolyl hydroxylase (PHD) activity, which relieves TRPA1 from the PHD-dependent hydroxylation of a proline residue located within the N-terminal ankyrin repeat domain (ARD) and leads to the opening of this channel[8]
We show that the modification of a single proline residue on TRPA1 augments its sensitivity to H2O2, which endows TRPA1 with cold sensitivity via transduction of reactive oxygen species (ROS) signalling

Summary

Introduction

Mammalian transient receptor potential ankyrin 1 (TRPA1) is a polymodal nociceptor that plays an important role in pain generation, but its role as a cold nociceptor is still controversial. By contrast, when hTRPA1-WT-expressing cells were pretreated with the PHD inhibitor DMOG (100 mM) for 2 h, the cold-evoked [Ca2 þ ]i responses were significantly facilitated, even in the absence of Pretreatment with mitoTEMPO (10 mM) significantly suppressed the cold-evoked [Ca2 þ ]i increase in both DMOG-pretreated hTRPA1-WT- and hTRPA1-P394A-expressing cells (Fig. 2a–c).

Results

Conclusion