title: Enhanced Expression of TREK-1 Is Related with Chronic Constriction Injury of Neuropathic Pain Mouse Model in Dorsal Root Ganglion.
abstract: Neuropathic pain is a complex state showing increased pain response with dysfunctional inhibitory neurotransmission. The TREK family, one of the two pore domain K⁺ (K2P) channel subgroups were focused among various mechanisms of neuropathic pain. These channels influence neuronal excitability and are thought to be related in mechano/thermosensation. However, only a little is known about the expression and role of TREK-1 and TREK-2, in neuropathic pain. It is performed to know whether TREK-1 and/ or 2 are positively related in dorsal root ganglion (DRG) of a mouse neuropathic pain model, the chronic constriction injury (CCI) model. Following this purpose, Reverse Transcription Polymerase Chain Reaction (RT-PCR) and western blot analyses were performed using mouse DRG of CCI model and compared to the sham surgery group. Immunofluorescence staining of isolectin- B4 (IB4) and TREK were performed. Electrophysiological recordings of single channel currents were analyzed to obtain the information about the channel. Interactions with known TREK activators were tested to confirm the expression. While both TREK-1 and TREK-2 mRNA were significantly overexpressed in DRG of CCI mice, only TREK-1 showed significant increase (~9 fold) in western blot analysis. The TREK-1-like channel recorded in DRG neurons of the CCI mouse showed similar current-voltage relationship and conductance to TREK-1. It was easily activated by low pH solution (pH 6.3), negative pressure, and riluzole. Immunofluorescence images showed the expression of TREK-1 was stronger compared to TREK-2 on IB4 positive neurons. These results suggest that modulation of the TREK-1 channel may have beneficial analgesic effects in neuropathic pain patients.
authors.affiliation: Department of Anesthesiology and Pain Medicine, CHA Bundang Medical Center, CHA University, Seongnam 13496, Republic of Korea.
authors.forename: Hyo Jo
authors.initials: HJ
authors.lastname: Han
authors.affiliation: Division of Natural Science, Ajou University, Suwon 16499, Republic of Korea.
authors.forename: Seung Wook
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Departments of Physiology and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727, Republic of Korea.
authors.forename: Gyu-Tae
authors.initials: GT
authors.lastname: Kim
authors.affiliation: Departments of Physiology and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727, Republic of Korea.
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, CHA Bundang Medical Center, CHA University, Seongnam 13496, Republic of Korea.
authors.forename: Byeonghun
authors.initials: B
authors.lastname: Kwon
authors.affiliation: Departments of Physiology and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727, Republic of Korea.
authors.forename: Dawon
authors.initials: D
authors.lastname: Kang
authors.affiliation: Department of Dental Anesthesiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea.
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Dental Anesthesiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea.
authors.forename: Kwang-Suk
authors.initials: KS
authors.lastname: Seo
keywords: Chronic constriction injury model; Dorsal root ganglion; Isolectin-B4; Neuropathic pain; TREK-1 expression