Human Recombinant Lactoferrin Promotes Differentiation and Calcification on MC3T3-E1 Cells

Lactoferrin (LF), known to be present in mammalian milk, has been reported to promote the proliferation of osteoblasts and suppress bone resorption by affecting osteoclasts. However, the mechanisms underlying the effects of human sources LF on osteoblast differentiation have not yet been elucidated, and almost studies have used LF from bovine sources. The presented study aimed to characterize the molecular mechanisms of bovine lactoferrin (IF-I) and human recombinant lactoferrin (LF-II) on MC3T3-E1 pre-osteoblast cells. MC3T3-E1 cells were treated with LF, ascorbic acid, and beta-glycerophosphate (beta-GP). Cell proliferation was analyzed using the MTT assay. Alkaline phosphatase activation and osteopontin expression levels were evaluated via cell staining and immunocytochemistry. The differentiation markers were examined using quantitative real-time PCR. The cell viability assay showed the treatment of 100 mu g/mL LF significantly increased; however, it was suppressed by the simultaneous treatment of ascorbic acid and beta-GP. Alizarin red staining showed that the 100 mu g/mL treatment of LF enhanced calcification. Quantitative real-time PCR showed a significant increase in osterix expression. The results suggest that treatment with both LFs enhanced MC3T3-E1 cell differentiation and promoted calcification. The mechanisms of calcification suggest that LFs are affected by an increase in osterix and osteocalcin mRNA levels.

Automated summary

Lactoferrin can promote osteoblast proliferation and suppress bone resorption. The mechanisms of human lactoferrin on osteoblast differentiation are still unclear, and most studies have used bovine lactoferrin. This study aimed to compare the effects of bovine lactoferrin and human recombinant lactoferrin on MC3T3-E1 osteoblast cells. The results showed that both lactoferrins enhanced MC3T3-E1 cell differentiation and calcification.