1. Academic Validation
  2. CXCL13/CXCR5 signaling contributes to diabetes-induced tactile allodynia via activating pERK, pSTAT3, pAKT pathways and pro-inflammatory cytokines production in the spinal cord of male mice

CXCL13/CXCR5 signaling contributes to diabetes-induced tactile allodynia via activating pERK, pSTAT3, pAKT pathways and pro-inflammatory cytokines production in the spinal cord of male mice

  • Brain Behav Immun. 2019 Aug;80:711-724. doi: 10.1016/j.bbi.2019.05.020.
Sisi Liu 1 Xueting Liu 2 Hui Xiong 1 Wen Wang 1 Yutong Liu 3 Liang Yin 1 Chuyue Tu 1 Hua Wang 3 Xuechuan Xiang 1 Jinhong Xu 1 Bailu Duan 1 Ailin Tao 2 Zhongqiu Zhao 4 Zhinan Mei 5
Affiliations

Affiliations

  • 1 School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China.
  • 2 The Second Afliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Guangzhou 510260, China.
  • 3 College of Life Science, South-Central University for Nationalities, Wuhan, China.
  • 4 Center for the Study of Itch, Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States; Barnes-Jewish Hospital, St. Louis, MO, USA.
  • 5 School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China. Electronic address: meizhinan@163.com.
Abstract

Painful diabetic neuropathy (PDN) is a severely debilitating chronic pain syndrome. Spinal chemokine CXCL13 and its receptor CXCR5 were recently demonstrated to play a pivotal role in the pathogenesis of chronic pain induced by peripheral tissue inflammation or nerve injury. In this study we investigated whether CXCL13/CXCR5 mediates PDN and the underlying spinal mechanisms. We used the db/db type 2 diabetes mice, which showed obvious hyperglycemia and obese, long-term mechanical allodynia, and increased expression of CXCL13, CXCR5 as well as pro-inflammatory cytokines TNF-α and IL-6 in the spinal cord. Furthermore, in the spinal cord of db/db mice there is significantly increased gliosis and upregulated phosphorylation of cell signaling kinases, including PERK, pAKT and pSTAT3. Mechanical allodynia and upregulated PERK, pAKT and pSTAT3 as well as production of TNF-α and IL-6 were all attenuated by the noncompetitive NMDA Receptor Antagonist MK-801. If spinal giving U0126 (a selective MEK Inhibitor) or AG490 (a Janus kinase (JAK)-STAT inhibitor) to db/db mice, both of them can decrease the mechanical allodynia, but only inhibit PERK (by U0126) or pSTAT3 (by AG490) respectively. Acute administration of CXCL13 in C57BL/6J mice resulted in exacerbated thermal hyperalgesia and mechanical allodynia, activation of the PERK, pAKT and pSTAT3 pathways and increased production of pro-inflammatory cytokines (IL-1β, TNF-α and IL-6), which were all attenuated by knocking out of Cxcr5. In all, our work showed that chemokine CXCL13 and its receptor CXCR5 in spinal cord contribute to the pathogenesis of PDN and may help develop potential novel therapeutic approaches for patients afflicted with PDN.

Keywords

CXCL13; CXCR5; Diabetic neuropathy; Neuroinflammation; Pain behavior; Spinal cord.

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