Effect of pregabalin administration upon reperfusion in a rat model of hyperglycemic stroke: Mechanistic insights associated with high-mobility group box 1

PLoS One. 2017 Feb 2;12(2):e0171147. doi: 10.1371/journal.pone.0171147. eCollection 2017.

Abstract

Hyperglycemia, which reduces the efficacy of treatments and worsens clinical outcomes, is common in stroke. Ability of pregabalin to reduce neuroexcitotoxicity may provide protection against stroke, even under hyperglycemia. We investigated its protective effect against hyperglycemic stroke and its possible molecular mechanisms. Male Wistar rats administered dextrose to cause hyperglycemia, underwent middle cerebral artery occlusion for 1 h and subsequent reperfusion. Rats were treated with an intraperitoneal injection of 30 mg/kg pregabalin or an equal amount of normal saline at the onset of reperfusion (n = 16 per group). At 24 h after reperfusion, neurological deficit, infarct volume, and apoptotic cell count were assessed. Western blot analysis was performed to determine protein expression of high-mobility group box 1 (HMGB1), toll-like receptor-4 (TLR-4), phosphorylated nuclear factor-kappa B (p-NF-κB), interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), phosphorylated inducible and endothelial nitric oxide synthase (p-iNOS, p-eNOS), Bcl-2, Bax, Cytochrome C, and caspase-3 in the brain. Pregabalin-treated rats showed significantly improved neurological function (31% decrease in score), reduced infarct size (by 33%), fewer apoptotic cells (by 63%), and lower expression levels of HMGB1, TLR4, p-NF-κB, IL-1β, and TNF- α, compared with control rats. Decreased p-iNOS and increased p-eNOS expressions were also observed. Expression of Bax, Cytochrome C, and cleaved caspase-3/caspase3 was significantly downregulated, while Bcl-2 expression was increased by pregabalin treatment. Pregabalin administration upon reperfusion decreased neuronal death and improved neurological function in hyperglycemic stroke rats. Cogent mechanisms would include attenuation of HMGB1/TLR-4-mediated inflammation and favorable modulation of the NOS.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Brain / drug effects
  • Brain / metabolism
  • Brain / pathology
  • Brain Infarction / complications
  • Brain Infarction / metabolism
  • Brain Infarction / therapy
  • Cytokines / metabolism
  • Disease Models, Animal
  • HMGB1 Protein / metabolism*
  • Hyperglycemia / complications
  • Hyperglycemia / drug therapy*
  • Hyperglycemia / metabolism*
  • Injections, Intraperitoneal
  • Male
  • NF-kappa B / metabolism
  • Neuroprotective Agents / administration & dosage
  • Nitric Oxide Synthase Type II / metabolism
  • Nitric Oxide Synthase Type III / metabolism
  • Pregabalin / administration & dosage*
  • Rats
  • Rats, Wistar
  • Reperfusion Injury / drug therapy*
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / pathology
  • Stroke / complications
  • Stroke / drug therapy*
  • Stroke / metabolism*
  • Toll-Like Receptor 4 / metabolism

Substances

  • Cytokines
  • HMGB1 Protein
  • Hbp1 protein, rat
  • NF-kappa B
  • Neuroprotective Agents
  • Tlr4 protein, rat
  • Toll-Like Receptor 4
  • Pregabalin
  • Nitric Oxide Synthase Type II
  • Nitric Oxide Synthase Type III
  • Nos2 protein, rat
  • Nos3 protein, rat

Grants and funding

This study was supported by a faculty research grant of Yonsei University College of Medicine (Seoul, Republic of Korea) for 6-2013-0069. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.