title: Inhibition of the osteoclast V-ATPase by small interfering RNAs.
abstract: The multisubunit enzyme V-ATPase harbours isoforms of individual subunits. a3 is one of four 116 kDa subunit a isoforms, and it is crucial for bone resorption. We used small interfering RNA (siRNA) molecules to knock down a3 in rat osteoclast cultures. Labeled siRNA-molecules entered osteoclasts via endocytosis and knocked down the a3 mRNA. Bone resorption was decreased in siRNA-treated samples due to decreased acidification and osteoclast inactivation. Expression of a1 did not respond to decreased a3 levels, suggesting that a1 does not compensate for a3 in osteoclast cultures. Subunit a3 is thus an interesting target for novel nucleic acid therapy.
authors.affiliation: Bone Biology Research Consortium, Department of Anatomy, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
authors.forename: Yingwei
authors.initials: Y
authors.lastname: Hu
authors.forename: Jonas
authors.initials: J
authors.lastname: Nyman
authors.forename: Pirkko
authors.initials: P
authors.lastname: Muhonen
authors.forename: H Kalervo
authors.initials: HK
authors.lastname: Väänänen
authors.forename: Tiina
authors.initials: T
authors.lastname: Laitala-Leinonen
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004705:Endocytosis / Q000502:physiology; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D010010:Osteoclasts / Q000201:enzymology*; D021122:Protein Subunits / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D025262:Vacuolar Proton-Translocating ATPases / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D021122:Protein Subunits; D034741:RNA, Small Interfering; D025262:Vacuolar Proton-Translocating ATPases