gms | German Medical Science

Objective: The undercarboxylated (un) osteocalcin (OC), form of osteoblasts derived OC, crosses the blood-brain barrier and binds to the neurons of brainstem, midbrain and hippocampus. Maternal OC crosses the placenta and prevents neuronal apoptosis in embryo. Injection of unOC improved the behavioral dysfunction in 6-hydroxydopamine-induced Parkinson’s diseases rat model. Even though the wide range of unOC actions have been shown, the unOC function is not completely understood. Here we asked if the unOC has an effect on neural stem cells.

Methods: The ReNcell VM cells were incubated without the growth factors and unOC was added in concentration of 10 or 30 ng/µl and cells were incubated for 0, 3, 5, or 7 days. At each of these days, RNA was isolated and RT-PCR was used to detect the changes in mRNA level of following genes: NANOG, VMAT2, Gad2, GFAP, NR4A2, PAX6, SOX2, TIMP2, TUBB3, UCHL1, Nestin, RbAp48. Western blot analysis was performed to verify the changes in protein level.

Results: Treatment of the cells with 10 or 30ng/µl of unOC for 5 days increased transcription of the human NANOG (Nanog Homeobox) gene significantly (*p<0.05). Additionally, VMAT2 (Vesicular Monoamine Transporter 2) was increased by addition of 10 ng/µl of unOC on day 5 (*p<0.05).

Conclusion: Here we showed that unOC influences the transcription of VMAT2 and NANOG. If this influence is direct or indirect is not known yet. We speculate that, OC role for the control of neuronal apoptosis in embryo could be by controlling the transcription of VMAT2. If unOC is required for NANOG’s function in the acquisition of pluripotency has yet to be clarified.