title: ALS-associated peripherin spliced transcripts form distinct protein inclusions that are neuroprotective against oxidative stress.
abstract: Intracellular proteinaceous inclusions are well-documented hallmarks of the fatal motor neuron disorder amyotrophic lateral sclerosis (ALS). The pathological significance of these inclusions remains unknown. Peripherin, a type III intermediate filament protein, is upregulated in ALS and identified as a component within different types of ALS inclusions. The formation of these inclusions may be associated with abnormal peripherin splicing, whereby an increase in mRNA retaining introns 3 and 4 (Per-3,4) leads to the generation of an aggregation-prone isoform, Per-28. During the course of evaluating peripherin filament assembly in SW-13 cells, we identified that expression of both Per-3,4 and Per-28 transcripts formed inclusions with categorically distinct morphology: Per-3,4 was associated with cytoplasmic condensed/bundled filaments, small inclusions (<10μM), or large inclusions (≥10μM); while Per-28 was associated with punctate inclusions in the nucleus and/or cytoplasm. We found temporal and spatial changes in inclusion morphology between 12 and 48h post-transfected cells, which were accompanied by unique immunofluorescent and biochemical changes of other ALS-relevant proteins, including TDP-43 and ubiquitin. Despite mild cytotoxicity associated with peripherin transfection, Per-3,4 and Per-28 expression increased cell viability during H2O2-mediated oxidative stress in BE(2)-M17 neuroblastoma cells. Taken together, this study shows that ALS-associated peripherin isoforms form dynamic cytoplasmic and intranuclear inclusions, effect changes in local endogenous protein expression, and afford cytoprotection against oxidative stress. These findings may have important relevance to understanding the pathophysiological role of inclusions in ALS.
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Jesse R
authors.initials: JR
authors.lastname: McLean
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Gaynor A
authors.initials: GA
authors.lastname: Smith
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Emily M
authors.initials: EM
authors.lastname: Rocha
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Teresia M
authors.initials: TM
authors.lastname: Osborn
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.
authors.forename: Samar
authors.initials: S
authors.lastname: Dib
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Hayes
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Beagan
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Tana B
authors.initials: TB
authors.lastname: Brown
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Tristan F S
authors.initials: TF
authors.lastname: Lawson
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA.
authors.forename: Penelope J
authors.initials: PJ
authors.lastname: Hallett
authors.affiliation: Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.
authors.forename: Janice
authors.initials: J
authors.lastname: Robertson
authors.affiliation: Neuroregeneration Research Institute, McLean Hospital, Harvard Medical School, Belmont, MA, USA. Electronic address: isacson@hms.harvard.edu.
authors.forename: Ole
authors.initials: O
authors.lastname: Isacson
mesh_terms: D002277:Carcinoma / Q000473:pathology; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D002479:Inclusion Bodies / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics*; D064531:Peripherins / Q000235:genetics* / Q000378:metabolism; D066263:Protein Aggregation, Pathological / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D025801:Ubiquitin / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C489427:MYC protein, human; C578994:PRPH protein, human; D064531:Peripherins; D020033:Protein Isoforms; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D025801:Ubiquitin; D014746:Vimentin; D006861:Hydrogen Peroxide
keywords: Aggregation; Amyotrophic lateral sclerosis (ALS); Inclusion; Intermediate filament; Peripherin; Splicing; Stress; TDP-43