1. Academic Validation
  2. TLR2 Mediates Microglial Activation and Contributes to Central Sensitization in a Recurrent Nitroglycerin-induced Chronic Migraine Model

TLR2 Mediates Microglial Activation and Contributes to Central Sensitization in a Recurrent Nitroglycerin-induced Chronic Migraine Model

  • Mol Neurobiol. 2023 Nov 27. doi: 10.1007/s12035-023-03781-2.
Xuejiao Liu # 1 Wenping Yang # 2 Chenlu Zhu # 1 Songtang Sun 1 Bin Yang 1 Shouyi Wu 1 Longde Wang 3 Zhiyan Liu # 4 Zhaoming Ge # 5
Affiliations

Affiliations

  • 1 Department of Neurology, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China.
  • 2 State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
  • 3 Expert Workstation of Academician Wang Longde, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China.
  • 4 Department of Neurology, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China. 347958394@qq.com.
  • 5 Department of Neurology, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China. gezhaoming5120@163.com.
  • # Contributed equally.
Abstract

Central sensitization is an important pathophysiological mechanism underlying chronic migraine (CM). Previous studies have shown that microglial activation and subsequent inflammation in the trigeminal nucleus caudalis (TNC) contribute to central sensitization. Toll-like Receptor 2 (TLR2) is a receptor expressed on the membrane of microglia and participates in central sensitization in inflammatory and chronic pain; however, its role in CM is unclear. Therefore, this study investigated TLR2 involvement in CM in detail. Mice treated with recurrent nitroglycerin (NTG) were used as a CM model. Hyperalgesia was assessed using a 50% paw mechanical threshold and a 50% periorbital threshold on a Von Frey filament pain meter. Western blotting and immunofluorescence analyses were used to detect the expression of TLR2, microglia, c-fos and CGRP in TNC. The expression of inflammatory factors (IL-6, IL-1β、 IL-10、TNF-α and IFN-β1) was detected using quantitative real-time polymerase chain reaction (qRT-PCR). A selective TLR2 Antagonist (C29) was systematically administered to observe its effect on hyperalgesia, microglia activation and the expression of c-fos, CGRP and inflammatory factors. Recurrent administration of NTG resulted in acute and chronic hypersensitivity, accompanied by upregulation of TLR2 expression and microglial activation in TNC. C29 partially inhibited pain hypersensitivity. C29 suppressed microglial activation induced by NTG administration. Inhibition of TLR2 reduced the expression of c-fos and CGRP in TNC after NTG treatment. C29 inhibited the expression of inflammatory mediators in TNC. These data showed that microglial TLR2 plays a critical role in the pathogenesis of CM by regulating microglial activation in TNC.

Keywords

Central sensitization; Chronic migraine; Hyperalgesia; Microglia; Nitroglycerin; TLR2.

Figures
Products