GKLF, a transcriptional activator of Txnip, drives microglia activation in kainic acid-induced murine models of epileptic seizures

Int Immunopharmacol. 2023 Aug:121:110426. doi: 10.1016/j.intimp.2023.110426. Epub 2023 Jun 8.

Abstract

Neuroinflammation is a major component of epilepsy. Gut-enriched Kruppel-like factor (GKLF), a transcription factor of Kruppel-like factor family, has been reported to promote microglia activation and mediate neuroinflammation. However, the role of GKLF in epilepsy remains poorly characterized. This study focused on the function of GKLF in neuron loss and neuroinflammation in epilepsy and the molecular mechanism underlying microglia activation induced by GKLF upon lipopolysaccharides (LPS) treatment. An experimental epileptic model was induced by an intraperitoneal injection of 25 mg/kg kainic acid (KA). Lentivirus vectors (Lv) carrying Gklf CDS or short hairpin RNA targeting Gklf (shGKLF) was injected into the hippocampus, resulting in Gklf overexpression or knockdown in the hippocampus. BV-2 cells were co-infected with Lv-shGKLF or/and Lv carrying thioredoxin interacting protein (Txnip) CDS for 48 h and treated with 1 μg/mL LPS for 24 h. Results showed that GKLF enhanced KA-induced neuronal loss, pro-inflammatory cytokine secretion, activation of NOD-like receptor protein-3 (NLRP3) inflammasomes and microglia, and TXNIP expression in the hippocampus. GKLF inhibition showed negative effects on LPS-induced microglia activation, as evidenced by reduced pro-inflammatory cytokine secretion and activation of NLRP3 inflammasomes. GKLF bound to Txnip promoter and increased TXNIP expression in LPS-activated microglia. Interestingly, Txnip overexpression reversed the inhibitory effect of Gklf knockdown on microglia activation. These findings indicated that GKLF was involved in microglia activation via TXNIP. This study demonstrates the underlying mechanism of GKLF in the pathogenesis of epilepsy and uncovers that GKLF inhibition may be a therapeutic strategy for epilepsy treatment.

Keywords: Epilepsy; Gut-enriched Kruppel-like factor; Microglia; NOD-like receptor protein-3; Seizures; Thioredoxin interacting protein.

MeSH terms

  • Animals
  • Carrier Proteins / genetics
  • Cytokines / metabolism
  • Disease Models, Animal
  • Epilepsy* / chemically induced
  • Inflammasomes / metabolism
  • Kainic Acid / pharmacology
  • Kruppel-Like Factor 4*
  • Lipopolysaccharides / pharmacology
  • Mice
  • Microglia
  • NLR Family, Pyrin Domain-Containing 3 Protein / genetics
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Neuroinflammatory Diseases
  • Seizures / chemically induced
  • Thioredoxins / metabolism
  • Transcription Factors / genetics

Substances

  • Carrier Proteins
  • Cytokines
  • Inflammasomes
  • Kainic Acid
  • Kruppel-Like Factor 4
  • Lipopolysaccharides
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Thioredoxins
  • Transcription Factors
  • Txnip protein, mouse
  • Klf4 protein, mouse