Vitamin K2 (MK4) functions were investigated by using the induced skin cell into osteoblast
compared with the control media. The real time PCR measured gene expression in both cultures at the fourth,
seventh, fourteenth, twenty first, twenty eighth, thirty fifth and forty second days of culture. The gene
expressions of osteocalcin, osteonectin, osteopontin , bone sialoprotein, CBFA1, Interleukin-6, Estrogen
receptors and collagen type1 were monitored by real time PCR. MK4 had strong power to stimulate gene
expression of osteocalcin and osteonectin after one week of culture but MK4 showed weak action on gene of
osteopontin, bone sialoprotein and interleukin-6. The gene of estrogens showed the marked expression of
estrogen receptor beta at the fourteenth day of culture while estrogen receptor alpha did not respond.MK4
could stimulate genes of RANKL and collagen type 1. This study supported the action of vitamin K2 for
enhancing the bone matrix.

Keywords: Gene expression, Osteocalcin, Osteonectin, Collagen type1, Stem cell, Vitamin K2, Osteoblast