Identification of avian sarcoplasmic reticulum Ca(2+)-ATPase (SERCA3) as a novel 1,25(OH)(2)D(3) target gene in the monocytic lineage.
Osteoclasts are postmitotic, multinucleated giant cells generated by the fusion of hematopoietic mononuclear precursors from the monocyte-macrophage lineage. In culture, adherent macrophages from blood-derived monocytes grow, gather, and fuse together to form multinucleated osteoclast-like cells. These events are controlled by 1,25(OH)(2)D(3). To sort out new 1,25(OH)(2)D(3) target genes involved in osteoclast differentiation, we have performed an RT-PCR differential display using mRNA from macrophages induced for 10 h by 1,25(OH)(2)D(3) compared to nontreated cells. We have identified a new target gene, a chick ATP-dependent Ca(2+) pump, ChkSERCA3. Although the level of the corresponding transcript increases during the differentiation process from macrophages to osteoclast-like cells, its steady-state level is downregulated by hormone treatment. The action of 1,25(OH)(2)D(3) on the Ca(2+)-ATPase gene expression is independent of de novo protein synthesis and is hormone dose dependent. This expression in adult chick was restricted to the hematopoietic cell lineage, spleen, lung, intestine, and brain, whereas no expression was detected in embryos. The function of the protein can be predicted from its high homology with the other members of the SR ATP-dependent Ca(2+) pump family, i.e., storage and control of cytosolic Ca(2+) directly regulated by 1, 25(OH)(2)D(3), further supporting the critical role for intracellular calcium in highly specialized cells such as osteoclasts.
Machuca
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Laboratoire de Biologie Moléculaire et Cellulaire de l'Ecole Normale Supérieure de Lyon, UMR5665 CNRS/ENS,INRA913, 46 Allée d'Italie, Lyon Cedex 07, 69364, France. imachuca@ens-lyon.fr
Domenget
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C
Jurdic
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P
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D000252:Calcium-Transporting ATPases / Q000235:genetics*; D002454:Cell Differentiation / Q000187:drug effects; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015726:Giant Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010802:Phylogeny; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology*; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D007527:Isoenzymes; D012333:RNA, Messenger; D000252:Calcium-Transporting ATPases; D002117:Calcitriol