Involvement of CX3CR1 in bone cancer pain through the activation of microglia p38 MAPK pathway in the spinal cord
- 作者：Ji-Hua Hu szhujh@gmail.com ; Jian-Ping Yang ; szyangjp@gmail.com ; Lei Liu zhuliulei@163.com ; Cai-Fang Li licaifang@126.com ; Li-Na Wang lenawang0303@yahoo.com.cn ; Fu-Hai Ji jifuhai@hotmail.com ; Hao Cheng chenghaojs@163.com
- 关键词：Bone cancer pain ; CX3CR1 ; Microglia ; p38 MAP kinase ; Spinal cord
- 刊名：Brain Research
- 出版年：2012
- 期刊代码：8_00068993
- 类别：neu
- 出版时间：17 July, 2012
- 卷：1465
- 期：Complete
- 页码：1-9
- 文件大小：1344 K
摘要
Previous studies have demonstrated that fractalkine, a newly discovered chemokine, is implicated in spinal cord neuron-to-microglia activation signaling as well as mediation of neuropathic and inflammatory pain via its sole receptor CX3CR1, which is specifically expressed on microglia. However, whether it is involved in bone cancer pain (BCP) and the underlying mechanisms have not been elucidated. In this study we utilized a Sprague-Dawley rat animal model, and our findings indicated that on day 6, 12, and 18 following bone cancer pain induced by Walker 256 cell inoculation, the expression level of CX3CR1 in the spinal cord gradually increased. Intrathecal injection of a neutralizing antibody against CX3CR1 not only delayed the initiation of mechanical allodynia, but also attenuated established pain sensitization of BCP rats. Furthermore, we demonstrated that blockade of CX3CR1 suppressed the activation of microglia and the expression of p38 mitogen-activated protein kinase (MAPK) in the spinal cord in BCP rats. These results suggest a new mechanism of BCP, in which the microglia CX3CR1/p38 signaling cascade potentially plays an important role in facilitating pain processing in BCP rats.