title: RNA interference targeting cathepsin B of the carcinogenic liver fluke, Opisthorchis viverrini.
abstract: Functional genomics have not been reported for Opisthorchis viverrini or the related fish-borne fluke, Clonorchis sinensis. Here we describe the introduction by square wave electroporation of Cy3-labeled small RNA into adult O. viverrini worms. Adult flukes were subjected to square wave electroporation employing a single pulse for 20 ms of 125V in the presence of 50 μg/ml of Cy3-siRNA. The parasites tolerated this manipulation and, at 24 and 48 h after electroporation, fluorescence from the Cy3-siRNA was evident throughout the parenchyma of the worms, with strong fluorescence evident in the guts and reproductive organs of the adult worms. Second, other worms were treated using the same electroporation settings with double stranded RNA targeting an endogenous papain-like cysteine protease, cathepsin B. This manipulation resulted in a significant reduction in specific mRNA levels encoding cathepsin B, and a significant reduction in cathepsin B activity against the diagnostic peptide, Z-Arg-Arg-AMC. This appears to be the first report of introduction of reporter genes into O. viverrini and the first report of experimental RNA interference (RNAi) in this fluke. The findings indicated the presence of an intact RNAi pathway in these parasites which, in turn, provides an opportunity to probe gene functions in this neglected tropical disease pathogen.
authors.affiliation: Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Jittiyawadee
authors.initials: J
authors.lastname: Sripa
authors.forename: Porntip
authors.initials: P
authors.lastname: Pinlaor
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Brindley
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
authors.forename: Sasithorn
authors.initials: S
authors.lastname: Kaewkes
authors.forename: Mark W
authors.initials: MW
authors.lastname: Robinson
authors.forename: Neil D
authors.initials: ND
authors.lastname: Young
authors.forename: Robin B
authors.initials: RB
authors.lastname: Gasser
authors.forename: Alex
authors.initials: A
authors.lastname: Loukas
authors.forename: Thewarach
authors.initials: T
authors.lastname: Laha
mesh_terms: D000818:Animals; D001650:Bile Duct Neoplasms / Q000469:parasitology; D001653:Bile Ducts, Intrahepatic / Q000469:parasitology; D002401:Cathepsin B / Q000235:genetics / Q000378:metabolism*; D018281:Cholangiocarcinoma / Q000469:parasitology; D006224:Cricetinae; D018274:Electroporation; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008647:Mesocricetus; D009889:Opisthorchiasis / Q000150:complications / Q000469:parasitology*; D009891:Opisthorchis / Q000235:genetics* / Q000378:metabolism; D000077153:Progranulins; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics; D018510:RNA, Helminth / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013997:Time Factors; D014161:Transduction, Genetic
chemical_list: D015801:Helminth Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000077153:Progranulins; D012330:RNA, Double-Stranded; D018510:RNA, Helminth; D012333:RNA, Messenger; D002401:Cathepsin B