title: Acute TrkB inhibition rescues phenobarbital-resistant seizures in a mouse model of neonatal ischemia.
abstract: Neonatal seizures are commonly associated with hypoxic-ischemic encephalopathy. Phenobarbital (PB) resistance is common and poses a serious challenge in clinical management. Using a newly characterized neonatal mouse model of ischemic seizures, this study investigated a novel strategy for rescuing PB resistance. A small-molecule TrkB antagonist, ANA12, used to selectively and transiently block post-ischemic BDNF-TrkB signaling in vivo, determined whether rescuing TrkB-mediated post-ischemic degradation of the K(+)-Cl(-) co-transporter (KCC2) rescued PB-resistant seizures. The anti-seizure efficacy of ANA12 + PB was quantified by (i) electrographic seizure burden using acute continuous video-electroencephalograms and (ii) post-treatment expression levels of KCC2 and NKCC1 using Western blot analysis in postnatal day (P)7 and P10 CD1 pups with unilateral carotid ligation. ANA12 significantly rescued PB-resistant seizures at P7 and improved PB efficacy at P10. A single dose of ANA12 + PB prevented the post-ischemic degradation of KCC2 for up to 24 h. As anticipated, ANA12 by itself had no anti-seizure properties and was unable to prevent KCC2 degradation at 24 h without follow-on PB. This indicates that unsubdued seizures can independently lead to KCC2 degradation via non-TrkB-dependent pathways. This study, for the first time as a proof-of-concept, reports the potential therapeutic value of KCC2 modulation for the management of PB-resistant seizures in neonates. Future investigations are required to establish the mechanistic link between ANA12 and the prevention of KCC2 degradation.
authors.affiliation: Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, 716 North Broadway, Baltimore, MD, 21205, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Kang
authors.affiliation: Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, 716 North Broadway, Baltimore, MD, 21205, USA.|Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.|Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: M V
authors.initials: MV
authors.lastname: Johnston
authors.affiliation: Neuroscience Laboratory, Hugo Moser Research Institute at Kennedy Krieger, 716 North Broadway, Baltimore, MD, 21205, USA.|Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Kadam
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000927:Anticonvulsants / Q000008:administration & dosage*; D001381:Azepines / Q000008:administration & dosage*; D001549:Benzamides / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D002545:Brain Ischemia / Q000150:complications*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D004195:Disease Models, Animal; D004569:Electroencephalography; D005260:Female; D008297:Male; D051379:Mice; D010634:Phenobarbital / Q000008:administration & dosage*; D020813:Receptor, trkB / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012640:Seizures / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D064506:Solute Carrier Family 12, Member 2 / Q000378:metabolism; D027981:Symporters / Q000378:metabolism; D000096922:K Cl- Cotransporters
chemical_list: D000927:Anticonvulsants; D001381:Azepines; D001549:Benzamides; D019208:Brain-Derived Neurotrophic Factor; D010634:Phenobarbital; D020813:Receptor, trkB; D064506:Solute Carrier Family 12, Member 2; D027981:Symporters; D000096922:K Cl- Cotransporters; C559317:ANA 12 compound; C578878:Slc12a2 protein, mouse
keywords: Bumetanide; KCC2; PB resistance; hypoxic-ischemic encephalopathy; neonatal seizure