A comparison of the biological activities of human osteoblast hFOB1.19 between iron excess and iron deficiency.
Bone metabolism has a close relationship with iron homeostasis. To examine the effects of iron excess and iron deficiency on the biological activities of osteoblast in vitro, human osteoblast cells (hFOB1.19) were incubated in a medium supplemented with 0-200 μmol/L ferric ammonium citrate and 0-20 μmol/L deferoxamine. The intracellular iron was measured by a confocal laser scanning microscope. Proliferation of osteoblasts was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Apoptotic cells were detected using annexin intervention V/PI staining with a flow cytometry. Alkaline phosphatase (ALP) activity was measured using an ALP assay kit. The number of calcified nodules and mineral area was evaluated by von Kossa staining assay. The expressions of type I collagen and osteocalcin of cultured osteoblasts were detected by reverse transcriptase polymerase chain reaction and Western blot. Intracellular reactive oxygen species (ROS) was measured using the oxidation-sensitive dye 2,7-dichlorofluorescin diacetate by flow cytometry. The results indicated that excessive iron inhibited osteoblast activity in a concentration-dependent manner. Low iron concentrations, in contrast, produced a biphasic manner on osteoblasts: mild low iron promoted osteoblast activity, but serious low iron inhibited osteoblast activity. Osteogenesis was optimal in certain iron concentrations. The mechanism underlying biological activity invoked by excessive iron may be attributed to increased intracellular ROS levels.
Department of Orthopaedics, The Second Affiliated Hospital of Soochow University, Suzhou, 215004, China.
Guo-Yang
GY
Zhao
Li-Ping
LP
Zhao
Yin-Feng
YF
He
Guang-Fei
GF
Li
Chao
C
Gao
Kai
K
Li
You-Jia
YJ
Xu
D000469:Alkaline Phosphatase / Q000378:metabolism; D018798:Anemia, Iron-Deficiency / Q000378:metabolism* / Q000473:pathology; D017209:Apoptosis / Q000187:drug effects; D002113:Calcification, Physiologic / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D003676:Deferoxamine / Q000494:pharmacology; D019587:Dietary Supplements / Q000009:adverse effects; D005290:Ferric Compounds / Q000009:adverse effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D059165:Hormesis; D006801:Humans; D007501:Iron / Q000378:metabolism* / Q000506:poisoning; D000090463:Iron Deficiencies; D019190:Iron Overload / Q000378:metabolism* / Q000473:pathology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects; D000644:Quaternary Ammonium Compounds / Q000009:adverse effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D017262:Siderophores / Q000494:pharmacology
D024042:Collagen Type I; D005290:Ferric Compounds; D000644:Quaternary Ammonium Compounds; D017382:Reactive Oxygen Species; D017262:Siderophores; D015675:Osteocalcin; D007501:Iron; D000469:Alkaline Phosphatase; D003676:Deferoxamine; C013531:ferric ammonium citrate