CXCL14 exacerbates seizures by inhibiting GABA metabolism in epileptic mice

Am J Transl Res. 2022 Sep 15;14(9):6222-6233. eCollection 2022.

Abstract

Objective: Epilepsy is a common central nervous system disorder with pathological mechanisms including inflammation, ion channel impairment, and neurotransmitter imbalance. Despite the rapid development of current anti-epileptic drugs, epilepsy is not well controlled, so there is still a need for research on the mechanisms and new drug targets for epilepsy. CXCL14 is a member of the CXC family of chemokines, and its receptor is currently unknown. Chemokines are the third major communication mediators in the central nervous system and play a role in many diseases. Therefore, we explore the expression of CXCL14 in epilepsy and its possible mechanisms.

Materials and methods: We chose the kainic acid (KA) mouse model as the epilepsy model, and studied the expression of CXCL14 in this model by western blot. Subsequently, after knocking down CXCL14, we explored the effect of CXCL14 on seizures by electrophysiology and FJB (Fluoro-Jade B) staining. Western blot and ELISA were used to explore the possible mechanism of CXCL14 affecting seizures.

Results: CXCL14 expression gradually increased after a seizure until it peaked at 72 hours and then gradually decreased again. The knockdown of CXCL14 resulted in prolonged seizure latency, decreased seizure grade, and reduced degenerative necrosis of neurons in mice. Levels of GABA (γ-aminobutyric acid), GAD67 (glutamate decarboxylase 67) and GABAA receptor (γ-aminobutyric acid A receptor) were increased.

Conclusion: Our results suggest that CXCL14 expression is increased after seizures and may exacerbate seizures by regulating GABA metabolism. Based on this, CXCL14 could be a new target for epilepsy treatment and antiepileptic drug development.

Keywords: CXCL14; GABA; GABA metabolism; chemokine; epilepsy; inflammation.