P2Y12 receptor mediates microglial activation via RhoA/ROCK pathway in the trigeminal nucleus caudalis in a mouse model of chronic migraine

作者：Feng Jing, Yixin Zhang, Ting Long, Wei He, Guangcheng Qin, Dunke Zhang, Lixue Chen, Jiying Zhou · 发表于：Journal of Neuroinflammation · 年份：2019 · DOI：10.1186/s12974-019-1603-4 · 被引用次数：146 · 研究领域：Migraine and Headache Studies、Pain Mechanisms and Treatments、Neuroinflammation and Neurodegeneration Mechanisms

BACKGROUND: Microglial activation contributes to the development of chronic migraine (CM). The P2Y12 receptor (P2Y12R), a metabolic purinoceptor that is expressed on microglia in the central nervous system (CNS), has been indicated to play a critical role in the pathogenesis of chronic pain. However, whether it contributes to the mechanism of CM remains unknown. Thus, the present study investigated the precise details of microglial P2Y12R involvement in CM. METHODS: Mice subjected to recurrent nitroglycerin (NTG) treatment were used as the CM model. Hyperalgesia were assessed by mechanical withdrawal threshold to electronic von Frey and thermal withdrawal latency to radiant heat. Western blot and immunohistochemical analyses were employed to detect the expression of P2Y12R, Iba-1, RhoA, and ROCK2 in the trigeminal nucleus caudalis (TNC). To confirm the role of P2Y12R and RhoA/ROCK in CM, we systemically administered P2Y12R antagonists (MRS2395 and clopidogrel) and a ROCK2 inhibitor (fasudil) and investigated their effects on microglial activation, c-fos, and calcitonin gene-related peptide (CGRP) expression in the TNC. To further confirm the effect of P2Y12R on microglial activation, we preincubated lipopolysaccharide (LPS)-treated BV-2 microglia with MRS2395 and clopidogrel. ELISA was used to evaluate the levels of inflammatory cytokines. RESULTS: The protein levels of P2Y12R, GTP-RhoA, ROCK2, CGRP, c-fos, and inducible nitric oxide synthase (iNOS) in the TNC were increased ...