| Objective: The aim of this study was to elucidate the mechanismsunderlying the anti-apoptotic action of lactoferrin (LF) in primary rat osteoblasts.Methods: Primary rat osteoblast cells were harvested by the mixed enzyme fromneonatal calvaria of Sprague Dawley rats. After treated with different concentrationsof lactoferrin (0,0.1,1,10,100,1000μg/mL) for24h, osteoblast apoptosis weretested by flow cytometer. The gene expression of IGF-1mRNA were measured byreal-time fluorescence quantitative PCR (RT-PCR). The lentiviral vector containingshort hairpin RNA targeting IGF-1was constructed. The primary osteoblast cells weredivided five groups: control group, LF group（10μg/mL）, negative IGF-1siRNA+LF(10μg/mL) group, IGF-1siRNA group, IGF-1siRNA+LF (10μg/mL) group. Thenosteoblast apoptosis were tested by flow cytometer. Resμlts:(1)1μg/mL,10μg/mL,100μg/mL LF all played a role of inhibiting osteoblast apoptosis. The LF markedlyinhibited the osteoblast apoptosis at10μg/mL concentration. But1000μg/mL LFpromoted osteoblast apoptosis.(2)10μg/mL,100μg/mL,1000μg/mL LF all play arole of promoting expression of IGF-1mRNA.(3)Apoptosis was significantlyinhibited (P<0.01) compared to the control group in both the10μg/mL LF group andthe negative IGF-1siRNA+10μg/mL LF group. In the IGF-1siRNA group, the rate ofapoptosis increased by10%(P<0.05). There were no significant differences in the rateof apoptosis between the IGF-1siRNA group and the IGF-1siRNA+10μg/mL LFgroup (P>0.05). Conclusion: The lactoferrin markedly inhibited the osteoblastapoptosis at10μg/mL concentration. Lactoferrin may inhibit osteoblast apoptosis byupregμlating the expression of IGF-1mRNA. |
