Ghrelin Upregulates Hoxb4 Gene Expression in Rat Bone Marrow Stromal Cells.

OBJECTIVES: Ghrelin is a peptide which has a proliferative and antiapoptotic effect in many cells including bone marrow stromal cells (BMSCs). Homeobox protein B4 (HOXB4) is a transcription factor involved in stem cell regeneration and survival. The aim of the study was to find out the efect of ghrelin on Hoxb4 expression in BMSCs. MATERIALS AND METHODS: In this experimental study, rat BMSCs were cultivated in Dulbecco's Modified Eagle Medium (DMEM). Passage three BMSCs were treated with ghrelin 100 µM for 48 hours. Real-time polymerase chain reaction (PCR) was carried out from the untreated BMSCs (B), BMSCs treated with 125 µM H2O2 (BH), BMSCs treated with 100 µM ghrelin then 125 µM H2O2 (BGH) and BMSCs treated with 100 µM ghrelin (BG) groups. For immunofluorescence, cells were incubated with an anti-HOXB4 monoclonal antibody. Primary antibodies were visualized using the Fluorescein isothiocyanate (FITC) method. All data are presented as mean ± SEM and P<0.05 was considered as statistical significant. RESULTS: Hoxb4 expression significantly increased in the BG compared with BH and BGH groups. Furthermore, 100 µM ghrelin, increased the mean of HOXB4 positive immunoreactive cells compared to the BH group. CONCLUSIONS: Ghrelin probably enhances proliferation and viability of BMSCs through Hoxb4 upregulation. However, the signaling pathway and other biological outcomes of this effect should be elucidated in different stem cells.