Region- or state-related differences in expression and activation of extracellular signal-regulated kinases (ERKs) in naïve and pain-experiencing rats

作者：Shewei Guo, Ming‐Gang Liu, Ya-Li Long, Liying Ren, Zhuo-Min Lu, Houyou Yu, Junfeng Hou, Hua Li, Cui-Ying Gao, Xiu-Yu Cui, AN Yang-yuan, Junfa Li, Lan-Feng Zhao, Jun Chen · 发表于：BMC Neuroscience · 年份：2007 · DOI：10.1186/1471-2202-8-53 · 被引用次数：27 · 研究领域：Pain Mechanisms and Treatments、Melanoma and MAPK Pathways、Spine and Intervertebral Disc Pathology

BACKGROUND: Extracellular signal-regulated kinase (ERK), one member of the mitogen-activated protein kinase (MAPK) family, has been suggested to regulate a diverse array of cellular functions, including cell growth, differentiation, survival, as well as neuronal plasticity. Recent evidence indicates a role for ERKs in nociceptive processing in both dorsal root ganglion and spinal cord. However, little literature has been reported to examine the differential distribution and activation of ERK isoforms, ERK1 and ERK2, at different levels of pain-related pathways under both normal and pain states. In the present study, quantitative blot immunolabeling technique was used to determine the spatial and temporal expression of ERK1 and ERK2, as well as their activated forms, in the spinal cord, primary somatosensory cortex (SI area of cortex), and hippocampus under normal, transient pain and persistent pain states. RESULTS: In naïve rats, we detected regional differences in total expression of ERK1 and ERK2 across different areas. In the spinal cord, ERK1 was expressed more abundantly than ERK2, while in the SI area of cortex and hippocampus, there was a larger amount of ERK2 than ERK1. Moreover, phosphorylated ERK2 (pERK2), not phosphorylated ERK1 (pERK1), was normally expressed with a high level in the SI area and hippocampus, but both pERK1 and pERK2 were barely detectable in normal spinal cord. Intraplantar saline or bee venom injection, mimicking transient or persistent pain resp...