Neuron-specific Kv1.1 deficiency is sufficient to cause epilepsy, premature death, and cardiorespiratory dysregulation

NEUROBIOLOGY OF DISEASE

卷:137

Article

Trosclair, Krystle¹  Dhaibar, Hemangini A.¹  Gautier, Nicole M.¹  Mishra, Vikas¹  Glasscock, Edward^1,2 

[1] Louisiana State Univ, Hlth Sci Ctr, Dept Cellular Biol & Anat, Shreveport, LA 71103 USA

[2] Southern Methodist Univ, Dept Biol Sci, Dallas, TX 75275 USA

关键词: Kcna1;    Kv1.1;    Sudden unexpected death in epilepsy (SUDEP);    Heart rate variability;    Epilepsy;    Apnea;   

DOI  :  10.1016/j.nbd.2020.104759

来源: Elsevier

【 摘 要 】

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related mortality, but the precise cellular substrates involved remain elusive. Epilepsy-associated ion channel genes with co-expression in brain and heart have been proposed as SUDEP candidate genes since they provide a singular unifying link between seizures and lethal cardiac arrhythmias. Here, we generated a conditional knockout (cKO) mouse with neuron-specific deletion of Kenai, a SUDEP-associated gene with brain-heart co-expression, to test whether seizure-evoked cardiac arrhythmias and SUDEP require the absence of Kv1.1 in both brain and heart or whether ablation in neurons is sufficient. To obtain cKO mice, we developed a foxed Kcna1 mouse which we crossed to mice with the Synapsin1-Cre transgene, which selectively deletes Kcna1 in most neurons. Molecular analyses confirmed neuron-specific Kcna1 deletion in cKO mice and corresponding loss of Kv1.1 except in cerebellum where Synapsinl-Cre is not highly expressed. Survival studies and electroencephalography, electrocardiography, and plethysmography recordings showed that cK0 mice exhibit premature death, epilepsy, and cardiorespiratory dysregulation but to a lesser degree than global knockouts. Heart rate variability (HRV) was increased in cK0 mice with peaks during daytime suggesting disturbed diurnal HRV patterns as a SUDEP biomarker. Residual Kv1.1 expression in cKO cerebellum suggests it may play an unexpected role in regulating ictal cardiorespiratory dysfunction and SUDEP risk. This work demonstrates the principle that channelopathies with brain-heart expression patterns can increase death risk by brain-driven mechanisms alone without a functionally compromised heart, reinforcing seizure control as a primary clinical strategy for SUDEP prevention.