Human lactoferrin exerts bi-directional actions on PC12 cell survival via ERK1/2 pathway.
Human lactoferrin (hLF) is a member of the transferrin family and is found in most body fluids of human. Recent study showed that hLF played some roles in the regulation of cell growth. However, the biological function of hLF in the central nervous system and neuronal cells is still unclear. The MTT was used to assay cell viability, ELISA tests were used to assay caspase activities, and TUNEL staining was used to test the cytotoxicity of hLF to the cells. Our result showed that 700 microg/ml hLF significantly reduced the cell viability and increased the caspase 3 and 8 activities in PC12 neuronal cells. TUNEL staining further showed that 700 microg/ml hLF was cytotoxic to the PC12 through apoptosis-mediated pathway. In addition, 700 microg/ml hLF significantly decreased the protein expressions of phosphorylated extracellular-signal-regulated kinase 1/2 (ERK1/2) and Bcl-2 in PC12 cells, whereas 50 microg/ml hLF significantly increased the phosphorylation of ERK1/2 which could be specifically inhibited by PD98059. Furthermore, 50 microg/ml hLF could not only up-regulate the Bcl-2 expression but also protect PC12 cells from FasL-induced apoptosis. In conclusion, hLF plays a crucial role in the regulation of apoptosis and anti-apoptosis in PC12 neuronal cells via ERK1/2 phosphorylation pathway.
Lin
Tsung-Yao
TY
Laboratory of Biophysics, Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan.
Chiou
Shih-Hwa
SH
Chen
Mei
M
Kuo
Cheng-Deng
CD
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002352:Carrier Proteins / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D053222:Fas Ligand Protein; D006801:Humans; D007781:Lactoferrin / Q000633:toxicity*; D020935:MAP Kinase Signaling System; D008562:Membrane Glycoproteins / Q000494:pharmacology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D016716:PC12 Cells; D010766:Phosphorylation; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats
D002352:Carrier Proteins; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505662:Faslg protein, rat; C490098:LTF protein, human; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D007781:Lactoferrin