title: Prevention of oculopharyngeal muscular dystrophy-associated aggregation of nuclear polyA-binding protein with a single-domain intracellular antibody.
abstract: Oculopharyngeal muscular dystrophy (OPMD) belongs to the group of protein aggregation disorders and is caused by extensions of the N-terminal polyalanine stretch of the nuclear polyA-binding protein 1 (PABPN1). The presence of PABPN1-containing intranuclear aggregates in skeletal muscle is unique for OPMD and is also observed in transgenic mouse and cell models for OPMD. These models consistently support a direct role for the protein aggregation in OPMD pathogenesis. We have isolated and characterized a diverse panel of single-domain antibody reagents (VHH), recognizing different epitopes in PABPN1. The antibody reagents specifically detect endogenous PABPN1 in cell lysates on western blot and label PABPN1 in cultured cells and muscle sections. When expressed intracellularly as intrabodies in a cellular model for OPMD, aggregation of PABPN1 was prevented in a dose-dependent manner. More importantly yet, these intrabodies could also reduce the presence of already existing aggregates. Given the domain specificity of VHH-mediated aggregation interference, this approach at least allows the definition of the nucleation kernel in aggregation-prone proteins, thus facilitating etiological insight into this and other protein aggregation disorders, and ultimately, it may well provide useful therapeutic agents.
authors.affiliation: Department of Molecular and Cellular Biology, University of Utrecht, The Netherlands. pverheesen@hotmail.com
authors.forename: Peter
authors.initials: P
authors.lastname: Verheesen
authors.forename: Anna
authors.initials: A
authors.lastname: de Kluijver
authors.forename: Silvana
authors.initials: S
authors.lastname: van Koningsbruggen
authors.forename: Marjolein
authors.initials: M
authors.lastname: de Brij
authors.forename: Hans J
authors.initials: HJ
authors.lastname: de Haard
authors.forename: Gert-Jan B
authors.initials: GJ
authors.lastname: van Ommen
authors.forename: Silvère M
authors.initials: SM
authors.lastname: van der Maarel
authors.forename: C Theo
authors.initials: CT
authors.lastname: Verrips
mesh_terms: D000818:Animals; D000906:Antibodies / Q000378:metabolism* / Q000627:therapeutic use; D015153:Blotting, Western; D019556:COS Cells; D002522:Chlorocebus aethiops; D004305:Dose-Response Relationship, Drug; D018604:Epitope Mapping; D006367:HeLa Cells; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000473:pathology*; D039141:Muscular Dystrophy, Oculopharyngeal / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D039103:Poly(A)-Binding Protein II / Q000235:genetics*
chemical_list: D000906:Antibodies; D039103:Poly(A)-Binding Protein II