title: Expression of new human inorganic pyrophosphatase in thyroid diseases: its intimate association with hyperthyroidism.
abstract: Inorganic pyrophosphatase (PPase) controls the level of inorganic pyrophosphate produced by biosynthesis of protein, RNA, and DNA. Thus, PPase is essential for life. PPase expression is unclear in the thyroid. We cloned a new human PPase, phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPPase), and established a rabbit polyclonal anti-LHPPase antibody. This is the first study to determine the PPase expression by immunohistochemistry and Western blot. Intranuclear LHPPase expression of thyrocytes was enhanced most prominently in Graves' disease and autonomously functional thyroid nodule. To estimate a regulating factor of subcellular localization of LHPPase, we examined its expression of Graves' disease-derived thyrocytes in vitro with the disease-originated serum. Nuclear expression of LHPPase was lost in cultured thyrocytes even with the serum, while its cytoplasmic expression was retained. The data suggest that increased expression of LHPPase is associated with hyperthyroidism. Intranuclear expression of LHPPase may not be regulated by Graves' disease-derived serum factors.
authors.affiliation: Department of Pathology and Biodefence, Faculty of Medicine, Saga University, Saga, Japan. koikeei@med.saga-u.ac.jp
authors.forename: Eisuke
authors.initials: E
authors.lastname: Koike
authors.forename: Shuji
authors.initials: S
authors.lastname: Toda
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Yokoi
authors.forename: Kenji
authors.initials: K
authors.lastname: Izuhara
authors.forename: Norimasa
authors.initials: N
authors.lastname: Koike
authors.forename: Kouichi
authors.initials: K
authors.lastname: Itoh
authors.forename: Kohji
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Hajime
authors.initials: H
authors.lastname: Sugihara
mesh_terms: D000906:Antibodies / Q000276:immunology; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006980:Hyperthyroidism / Q000201:enzymology* / Q000473:pathology; D007150:Immunohistochemistry; D043564:Inorganic Pyrophosphatase / Q000276:immunology / Q000378:metabolism*
chemical_list: D000906:Antibodies; D043564:Inorganic Pyrophosphatase