Excess iron inhibits osteoblast metabolism.
Hemochromatosis is an iron overload disorder associated with osteopenia and osteoporosis. To learn more about the effects of iron on bone cells, we examined the effects of ferric ion on the proliferation, differentiation, and mineralization of two types of cultured osteoblasts, the cell line MC3T3-E1 and rat calvarial osteoblast-like (ROB) cells. We used ferric ammonium citrate (FAC) as a donor of ferric ion, and FAC inhibited the proliferation of MC3T3-E1 cells in a dose-dependent manner. FAC (0.1-1 microg/ml) inhibited indices of osteoblast differentiation, such as the expression of type I collagen (mRNA and protein), the activity of alkaline phosphatase, and the deposition of calcium by osteoblasts. These results suggest that iron overload might give rise to osteoporosis by inhibiting osteoblast proliferation and differentiation.
Yamasaki
Kanako
K
Department of Biomedical Engineering, Toin University of Yokohama, Yokohama 225-8502, Japan.
Hagiwara
Hiromi
H
D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001842:Bone and Bones / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019343:Citric Acid / Q000494:pharmacology; D024042:Collagen Type I / Q000378:metabolism; D007501:Iron / Q000633:toxicity*; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012886:Skull / Q000187:drug effects / Q000378:metabolism
D024042:Collagen Type I; D000644:Quaternary Ammonium Compounds; D019343:Citric Acid; C481046:ammonium citrate; D007501:Iron; D000469:Alkaline Phosphatase; D002118:Calcium