title: RANKL-induced schlafen2 is a positive regulator of osteoclastogenesis.
abstract: Osteoclasts are hematopoietic lineage derived-multinucleated cells that resorb bone. Their activity in balance with that of osteoblast is essential for bone homeostasis. Receptor activator of NF-kappaB ligand (RANKL) is known as an essential cytokine for the osteoclastogenesis, and c-Jun signaling in cooperation with NFAT family is crucial for RANKL-regulated osteoclastogenesis. We show here that schlafen2 (Slfn2), a member of a new family of growth regulatory genes involved in thymocyte development, is critical for osteoclastogenesis. RANKL selectively induces Slfn2 expression in osteoclast precursors via Rac1 signaling pathway. Targeted inhibition of Slfn2 by small interfering RNAs (siRNAs) markedly inhibits the formation of osteoclasts by diminishing the activation of c-Jun and the expression of c-Jun and NFATc1. In contrast, the overexpression of Slfn2 markedly increased phosphorylation and transactivation of c-Jun by RANKL. Together, these results indicate that Slfn2 has an essential role in osteoclastogenesis, functioning upstream of c-Jun and NFATc1.
authors.affiliation: Division of Life and Pharmaceutical Sciences, Center for Cell Signaling and Drug Discovery Research, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors.forename: Na Kyung
authors.initials: NK
authors.lastname: Lee
authors.forename: Han Kyung
authors.initials: HK
authors.lastname: Choi
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Yoo
authors.forename: Jihye
authors.initials: J
authors.lastname: Shin
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D050778:NFATC Transcription Factors / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism / Q000494:pharmacology*; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D050778:NFATC Transcription Factors; D016755:Proto-Oncogene Proteins c-jun; D053245:RANK Ligand; D034741:RNA, Small Interfering; C521352:schlafen-2 protein, mouse; D020830:rac1 GTP-Binding Protein