Menaquinone-7 regulates gene expression in osteoblastic MC3T3E1 cells.
Previous study has shown that the vitamin K2 analog menaquinone-7 (MK-7) induces expression of the osteoblast-specific genes osteocalcin, osteoprotegerin, receptor activator of NFkappaB, and its ligand. Since MK-7 may also regulate osteoblast cell function, we examined the expression of osteoblast genes regulated by MK-7 administration. Differences between gene expression in control and MK-7-administered MC3T3E1 cells were analyzed using the suppression subtractive hybridization method. After 24 h of MK-7 administration, genes upregulated by MK-7 included tenascin C and BMP2. Genes downregulated by MK-7 administration included biglycan and butyrophilin. Real-time PCR showed a marked increase in tenascin C. When the protein level was examined using Western blot analysis, tenascin C was higher in MK-7-administered cells than in control cells. These results indicated that MK-7 affected the cellular function of osteoblastic MC3T3E1 cells. Considering BMP2 mRNA expression was higher in MK-7-administered cells than in control cells, the effect of MK-7 administration on the signal transduction system was examined. Western blot analysis showed that cells administered MK-7 displayed a higher phosphorylated Smad1 level than control cells. Because MC3T3E1 cells have a nuclear binding receptor for MK-7, this result might indicate an indirect effect of MK-7 through BMP2 production.
Katsuyama
Hironobu
H
Department of Public Health, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan. katsu@med.kawasaki-m.ac.jp
Saijoh
Kiyofumi
K
Otsuki
Takemi
T
Tomita
Masafumi
M
Fukunaga
Masao
M
Sunami
Shigeo
S
D000818:Animals; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects*; D051379:Mice; D009693:Nucleic Acid Hybridization; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D019063:Tenascin / Q000235:genetics; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000494:pharmacology
D012333:RNA, Messenger; D019063:Tenascin; D024482:Vitamin K 2; C062629:menaquinone 7