Taurine inhibits osteoclastogenesis through the taurine transporter
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Several studies have suggested a direct link between taurine and bone homeostasis. However, the mechanisms of taurine on the regulation of bone metabolism have not been elucidated. Using a coculture of osteoblasts and bone marrow cells as a model for the study of osteoclastogenesis, RANKL-stimulated RAW264.7 cells and M-CSF- and RANKL-induced bone marrow macrophages were investigated to elucidate the possible roles of taurine in osteoclastogenesis. Taurine inhibited osteoclastogenesis in the coculture of osteoblasts and bone marrow cells, but did not influence the expression of OPG and RANKL in osteoblasts. The taurine transporter (TAUT) expressed by RAW264.7 and bone marrow macrophages exhibited typical taurine uptake activity. Taurine directly reduced osteoclastogenesis in RANKL-stimulated RAW264.7 cells and M-CSF- and RANKL-induced bone marrow macrophages, while TAUT siRNA relieved this effect. Our study demonstrated that taurine directly inhibited osteoclastogenesis through the taurine transporter. Taken together, these data suggest that taurine plays a direct role in bone homeostasis by inhibiting osteoclastogenesis.
KeywordsTaurine Taurine transporter Osteoclastogenesis siRNA
The National Natural Science Foundation of China (No. 30801174) and the Ph. D. Programs Foundation of the Ministry of Education of China (No. 200805331017).
- Koide M, Okahashi N, Tanaka R, Kazuno K, Shibasaki K, Yamazaki Y, Kaneko K, Ueda N, Ohguchi M, Ishihara Y, Noguchi T, Nishihara T (1999) Inhibition of experimental bone resorption and osteoclast formation and survival by 2-aminoethanesulphonic acid. Arch Oral Biol 44:711–719CrossRefPubMedGoogle Scholar
- Liu YS, Lu Y, Liu W, Xie H, Luo XH, Wu XP, Yuan LQ, Liao EY (2009) Connective tissue growth factor is a downstream mediator for peptin-induced proliferation and differentiation in human osteoblasts. Amino Acids [Epub ahead of print]Google Scholar
- Warskulat U, Flogel U, Jacoby C, Hartwig HG, Thewissen M, Merx MW, Molojavyi A, Heller-Stilb B, Schrader J, Haussinger D (2004) Taurine transporter knockout depletes muscle taurine levels and results in severe skeletal muscle impairment but leaves cardiac function uncompromised. FASEB J 18:577–579PubMedGoogle Scholar
- Yasutomi C, Nakamuta H, Fujita T, Takenaga T, Koida M (2002) Anti-osteopenic effect of taurine: possible involvement of activated MEK-ERK-Cbfa1 signaling. Nippon Yakurigaku Zasshi 120:114–115Google Scholar