title: RNA sequencing of synaptic and cytoplasmic Upf1-bound transcripts supports contribution of nonsense-mediated decay to epileptogenesis.
abstract: The nonsense mediated decay (NMD) pathway is a critical surveillance mechanism for identifying aberrant mRNA transcripts. It is unknown, however, whether the NMD system is affected by seizures in vivo and whether changes confer beneficial or maladaptive responses that influence long-term outcomes such the network alterations that produce spontaneous recurrent seizures. Here we explored the responses of the NMD pathway to prolonged seizures (status epilepticus) and investigated the effects of NMD inhibition on epilepsy in mice. Status epilepticus led to increased protein levels of Up-frameshift suppressor 1 homolog (Upf1) within the mouse hippocampus. Upf1 protein levels were also higher in resected hippocampus from patients with intractable temporal lobe epilepsy. Immunoprecipitation of Upf1-bound RNA from the cytoplasmic and synaptosomal compartments followed by RNA sequencing identified unique populations of NMD-associated transcripts and altered levels after status epilepticus, including known substrates such as Arc as well as novel targets including Inhba and Npas4. Finally, long-term video-EEG recordings determined that pharmacologic interference in the NMD pathway after status epilepticus reduced the later occurrence of spontaneous seizures in mice. These findings suggest compartment-specific recruitment and differential loading of transcripts by NMD pathway components may contribute to the process of epileptogenesis.
authors.affiliation: Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Claire M
authors.initials: CM
authors.lastname: Mooney
authors.affiliation: Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Jimenez-Mateos
authors.affiliation: Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Engel
authors.affiliation: Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Catherine
authors.initials: C
authors.lastname: Mooney
authors.affiliation: Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Mairead
authors.initials: M
authors.lastname: Diviney
authors.affiliation: Department of Molecular Biology and Genetics and Center for DNA Nanotechnology and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark.
authors.forename: Morten T
authors.initials: MT
authors.lastname: Venø
authors.affiliation: Department of Molecular Biology and Genetics and Center for DNA Nanotechnology and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Kjems
authors.affiliation: Beaumont hospital, Beaumont, Dublin, Ireland.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Farrell
authors.affiliation: Beaumont hospital, Beaumont, Dublin, Ireland.
authors.forename: Donncha F
authors.initials: DF
authors.lastname: O'Brien
authors.affiliation: Beaumont hospital, Beaumont, Dublin, Ireland.
authors.forename: Norman
authors.initials: N
authors.lastname: Delanty
authors.affiliation: Department of Physiology &Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: David C
authors.initials: DC
authors.lastname: Henshall
mesh_terms: D000818:Animals; D019295:Computational Biology; D003593:Cytoplasm / Q000378:metabolism*; D004827:Epilepsy / Q000235:genetics*; D004833:Epilepsy, Temporal Lobe / Q000235:genetics; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D047468:Immunoprecipitation; D008297:Male; D008810:Mice, Inbred C57BL; D059365:Nonsense Mediated mRNA Decay / Q000235:genetics*; D011485:Protein Binding; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D017423:Sequence Analysis, RNA; D054852:Small Molecule Libraries / Q000494:pharmacology; D013226:Status Epilepticus / Q000235:genetics; D013569:Synapses / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; C484446:Rent1 protein, mouse; D054852:Small Molecule Libraries; D015534:Trans-Activators; D020365:RNA Helicases; C101828:UPF1 protein, human