Variants of Neural Nitric Oxide Synthase in the Spinal Cord of Neuropathic Rats and Their Effects on Nuclear Factor-κB (NF-κB) Activity in PC12 Cells

Jin, Xiao-Gao; He, Song-Qing; Yan, Xue-Tao; Zhang, Guangxiong; Wan, Li; Wang, Jintao; Li, Yawen; Tian, Xuebi; Tian, Yuke; Luo, Ailin

doi:10.1016/j.jpain.2008.07.009

« Previous Next »The Journal of Pain
Volume 10, Issue 1 , Pages 80-89, January 2009

Variants of Neural Nitric Oxide Synthase in the Spinal Cord of Neuropathic Rats and Their Effects on Nuclear Factor-κB (NF-κB) Activity in PC12 Cells

Xiao-Gao Jin
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Song-Qing He
- Department of Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Xue-Tao Yan
- Department of Anesthesiology, Taihe Hospital, Yunyang Medical College, Shiyan, Hubei Province, China
Guangxiong Zhang
- Department of Anesthesiology, Hubei Provincial Corps Hospital, Chinese People's Armed Police Forces, Wuhan, Hubei Province, China
Li Wan
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Jintao Wang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Yawen Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Xuebi Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Yuke Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
Ailin Luo
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
- Address reprint requests to Dr. Ailin Luo, Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China

Received 4 March 2008; received in revised form 13 July 2008; accepted 22 July 2008. published online 03 November 2008.

Abstract

Neuropathic pain due to nerve injury is associated with overactivity of spinal N-methyl-D-aspartate (NMDA) receptors and nitric oxide synthases (NOS). Spinal NOS and NMDA receptors could act in a concerted manner to excite each other in nociceptive signaling. Among the 3 major NOS isoforms, neuronal NOS (nNOS) has the most functional relationship with NMDA receptors through a PDZ-PDZ (PSD-95, Dlg, ZO-1 homology) postsynapse interaction. However, some nNOS variants lack the PDZ domain, which may result in the changes in the interaction with the NMDA receptor and subsequent localization and enzymatic activity. The aim of this study was to determine which nNOS variants are expressed in the spinal cord in neuropathic rats and deduce their role in neuropathic pain by testing the effects of these kinds of nNOS on nuclear factor-κB (NF-κB) activity in PC12 cells. Western blot analysis revealed that there were at least 3 bands of nNOS (155, 135, and 125 kDa) in the spinal cord and, moreover, that nNOS at 135 kDa decreased significantly after development of neuropathic pain. 5′-RACE-PCR and Southern blots determined that the nNOS at 155 and 135 kDa corresponded to nNOSα and nNOSβ, respectively, which was confirmed by RT-PCR. PC12 cells transfected with the nNOSα gene had no effect on NF-κB activity, but nNOSβ without the PDZ domain significantly decreased that in PC12 cells. Considering the importance of spinal NF-κB signaling in neuropathic rat, it could be concluded that changes in spinal nNOS variants and quantity after peripheral nerve injury implicate nNOS in the generation of neuropathic pain.

Perspective

This article presents data demonstrating that nNOS variants change in the spinal cord of the rats after neuropathic pain and result in differential effects on NF-κB activity in PC12 cells. These changes in nNOS variants and their different characteristics may account for the spinal NO paradox role in neuropathic pain. Furthermore, these data suggest that nNOSβ̣ may represent a new therapeutic target for the treatment of chronic neuropathic pain.

Key words: Neural nitric oxide variants, neuropathic rats, NF-κB activity