Acid sphingomyelinase regulates osteoclastogenesis by modulating sphingosine kinases downstream of RANKL signaling.
Acid sphingomyelinase (ASM) was identified as a gene induced by NFAT2 activation in osteoclasts. Suppression of ASM expression in bone marrow macrophages by knockdown enhanced c-Fos/NFAT2 expression, increasing the number of TRAP-positive multinucleated cells in vitro. SphK1 was upregulated during the late stage of osteoclastogenesis, while SphK2 expression remained constant. SphK1 was downregulated following ASM knockdown, while SphK2 levels were unchanged. Experiments using shRNA and catalytically-inactive form demonstrated inhibitory and stimulatory activities on osteoclast formation of SphK1 and SphK2, respectively. These results suggest that ASM regulates osteoclastogenesis by modulating the balance between SphK1 and SphK2 downstream of RANKL signaling.
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
Xilinqiqige
X
Bao
Takuya
T
Ogawa
Satoru
S
Se
Motofusa
M
Akiyama
Anton
A
Bahtiar
Tatsuo
T
Takeya
Norihiro
N
Ishida-Kitagawa
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D051379:Mice; D050778:NFATC Transcription Factors / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology* / Q000201:enzymology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D053245:RANK Ligand / Q000378:metabolism; D013108:Sphingomyelin Phosphodiesterase / Q000235:genetics / Q000502:physiology*; D000099157:Sphingosine Kinase
D050778:NFATC Transcription Factors; D017853:Phosphotransferases (Alcohol Group Acceptor); D053245:RANK Ligand; D013108:Sphingomyelin Phosphodiesterase; D000099157:Sphingosine Kinase; C505689:Tnfsf11 protein, mouse