Bovine lactoferrin protects RSC96 Schwann cells from tumor necrosis factor-alpha-induced growth arrest via extracellular-signal-regulated kinase 1/2.

Bovine lactoferrin (bLF) is a member of the transferrin protein family that is abundant in bovine milk. Recent studies have shown that bLF plays roles in the regulation of cell growth. However, the biological function of bLF in the peripheral nervous system is still unclear. In this study, the immortalized rat Schwann cells (RSC96) were exposed to bLF at concentrations ranging from 10 to 800 microg/ml for 48 h and compared with control group. The bromodeoxyuridine BrdU cell viability assay was used to examine the effect of bLF on cell viability of RSC96 Schwann cells. Cell-counting test was used to assay the growth rate of RSC96 cells after exposure to bLF, and immunoblot analysis was used to test the signaling pathway controlled by bLF in the RSC96 cells. It was found that the viability of the RSC96 cells was increased by more than 25% when treated with 50 microg/ml bLF and the cell number of RSC96 cells was increased by more than threefold when treated with 800 microg/ml bLF. Our results showed that bLF could significantly improve viability and number of RSC96 Schwann cells. Also, bLF could significantly increase the phosphorylation state of extracellular-signal regulated kinase 1/2 (ERK1/2) that could be specifically inhibited by PD98059. Furthermore, bLF could not only protect RSC96 cells from tumor necrosis factor-alpha (TNF-alpha) -induced growth arrest but could also restore proliferation rate in TNF-alpha-treated RSC96 cells. In conclusion, bLF plays a crucial role in the proliferation of RSC96 Schwann cells and the protection of RSC96 Schwann cells from TNF-alpha-induced growth arrest via ERK1/2 protein.