Exendin-4 attenuates pain-induced cognitive impairment by alleviating hippocampal neuroinflammation in a rat model of spinal nerve ligation

• Published in: Neural regeneration research Vol. 15; no. 7; pp. 1333 - 1339
• Main Authors: Cui, Shan-Shan, Feng, Xiao-Bo, Zhang, Bing-Hong, Xia, Zhong-Yuan, Zhan, Li-Ying
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer India Pvt. Ltd 01.07.2020; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China%Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China; Wolters Kluwer - Medknow; Wolters Kluwer Medknow Publications
• Subjects: Anti-inflammatory agents; Apoptosis; astrocyte; chronic pain; cognitive impairment; exendin-4; hippocampal dentate gyrus; microglia; morris water maze; neuroinflammation; spinal nerve ligation; Catheters; Chronic pain; Cognitive ability; Enzymes; Glucagon; Immunoglobulins; Intubation; Ischemia; Laboratory animals; Pain; Peptides; Proteins; Rodents; Software; United States > US; China; chronic pain; Morris water maze; neuroinflammation; spinal nerve ligation; cognitive impairment; hippocampal dentate gyrus; astrocyte; exendin-4; microglia
• ISSN: 1673-5374; 1876-7958
• DOI: 10.4103/1673-5374.272620

Glucagon-like peptide-1 receptor has anti-apoptotic, anti-inflammatory, and neuroprotective effects. It is now recognized that the occurrence and development of chronic pain are strongly associated with anti-inflammatory responses; however, it is not clear whether glucagon-like peptide-1 receptor regulates chronic pain via anti-inflammatory mechanisms. We explored the effects of glucagon-like peptide-1 receptor on nociception, cognition, and neuroinflammation in chronic pain. A rat model of chronic pain was established using left L5 spinal nerve ligation. The glucagon-like peptide-1 receptor agonist exendin-4 was intrathecally injected into rats from 10 to 21 days after spinal nerve ligation. Electrophysiological examinations showed that, after treatment with exendin-4, paw withdrawal frequency of the left limb was significantly reduced, and pain was relieved. In addition, in the Morris water maze test, escape latency increased and the time to reach the platform decreased following exendin-4 treatment. Immunohistochemical staining and western blot assays revealed an increase in the numbers of activated microglia and astrocytes in the dentate gyrus of rat hippocampus, as well as an increase in the expression of tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6. All of these effects could be reversed by exendin-4 treatment. These findings suggest that exendin-4 can alleviate pain-induced neuroinflammatory responses and promote the recovery of cognitive function via the glucagon-like peptide-1 receptor pathway. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Renmin Hospital of Wuhan University of China (approval No. WDRM 20171214) on September 22, 2017.