title: Stress Conditions Increase Vimentin Cleavage by Omi/HtrA2 Protease in Human Primary Neurons and Differentiated Neuroblastoma Cells.
abstract: Dysfunctional Omi/HtrA2, a mitochondrial serine protease, has been implicated in various neurodegenerative disorders. Despite the wealth of evidence on the roles of Omi/HtrA2 in apoptosis, little is known about its cytosolic targets, the cleavage of which could account for the observed morphological changes such as cytoskeletal reorganizations in axons. By proteomic analysis, vimentin was identified as a substrate for Omi/HtrA2 and we have reported increased Omi/HtrA2 protease activity in Alzheimer disease (AD) brain. Here, we investigated a possible link between Omi/HtrA2 and vimentin cleavage, and consequence of this cleavage on mitochondrial distribution in neurons. In vitro protease assays showed vimentin to be cleaved by Omi/HtrA2 protease, and proximity ligation assay demonstrated an increased interaction between Omi/HtrA2 and vimentin in human primary neurons upon stress stimuli. Using differentiated neuroblastoma SH-SY5Y cells, we showed that Omi/HtrA2 under several different stress conditions induces cleavage of vimentin in wild-type as well as SH-SY5Y cells transfected with amyloid precursor protein with the Alzheimer disease-associated Swedish mutation. After stress treatment, inhibition of Omi/HtrA2 protease activity by the Omi/HtrA2 specific inhibitor, Ucf-101, reduced the cleavage of vimentin in wild-type cells. Following altered vimentin filaments integrity by stress stimuli, mitochondria was redistributed in differentiated SH-SY5Y cells and human primary neurons. In summary, the findings outlined in this paper suggest a role of Omi/HtrA2 in modulation of vimentin filamentous structure in neurons. Our results provide important findings for understanding the biological role of Omi/HtrA2 activity during stress conditions, and give knowledge of interplay between Omi/HtrA2 and vimentin which might affect mitochondrial distribution in neurons.
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Bérangère
authors.initials: B
authors.lastname: Lucotte
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Tajhizi
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Dareen
authors.initials: D
authors.lastname: Alkhatib
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Eva-Britt
authors.initials: EB
authors.lastname: Samuelsson
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Wiehager
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Sophia
authors.initials: S
authors.lastname: Schedin-Weiss
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Sundström
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Winblad
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden.
authors.forename: Lars O
authors.initials: LO
authors.lastname: Tjernberg
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society (NVS), Center for Alzheimer Research, Division for Neurogeriatrics, Novum 5th floor, SE-141 57, Huddinge, Sweden. homira.behbahani@ki.se.
authors.forename: Homira
authors.initials: H
authors.lastname: Behbahani
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism; D001369:Axons / Q000648:ultrastructure; D045744:Cell Line, Tumor; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D000074923:High-Temperature Requirement A Serine Peptidase 2; D006801:Humans; D053583:Interleukin-1beta / Q000633:toxicity; D007382:Intermediate Filaments / Q000648:ultrastructure; D017879:Isothiocyanates / Q000633:toxicity; D008928:Mitochondria / Q000502:physiology; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020125:Mutation, Missense; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009447:Neuroblastoma / Q000473:pathology*; D055495:Neurogenesis / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D017354:Point Mutation; D011744:Pyrimidinones / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013312:Stress, Physiological / Q000502:physiology*; D013454:Sulfoxides; D013871:Thiones / Q000494:pharmacology; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology; D014415:Tunicamycin / Q000633:toxicity; D014746:Vimentin / Q000378:metabolism*
chemical_list: D016564:Amyloid beta-Protein Precursor; D016895:Culture Media, Serum-Free; D053583:Interleukin-1beta; D017879:Isothiocyanates; D024101:Mitochondrial Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011744:Pyrimidinones; D015842:Serine Proteinase Inhibitors; D013454:Sulfoxides; D013871:Thiones; C501517:UCF 101; D014746:Vimentin; D014415:Tunicamycin; D014212:Tretinoin; D012697:Serine Endopeptidases; C000615914:HTRA2 protein, human; D000074923:High-Temperature Requirement A Serine Peptidase 2; C016766:sulforaphane
keywords: APPswe; Alzheimer disease; Human primary neurons; Mitochondria; Omi/HtrA2; Vimentin