Iron chelator deferoxamine alters iron-regulatory genes and proteins and suppresses osteoblast phenotype in fetal rat calvaria cells
Iron chelator deferoxamine alters iron-regulatory genes and proteins and suppresses osteoblast phenotype in fetal rat calvaria cells
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DOI：
10.1016/j.bone.2010.01.376
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发表时间：
2010-05-01
期刊：
影响因子：
4.1
通讯作者：
Kipp, Deborah E.
中科院分区：
文献类型：
--
作者：
Messer, Jonathan G.;Cooney, Paula T.;Kipp, Deborah E.
尽管有证据表明缺铁会对骨密度产生不利影响，但很少有研究描述低铁状态对成骨细胞发生的影响程度。本研究的目的是通过测量铁调节基因和蛋白质表达来评估细胞内铁状态的改变，并描述在分化过程中用铁螯合剂去铁胺（DFOM）处理的原代细胞中成骨细胞表型的发展。使用充分描述的胎鼠颅盖模型，在整个分化过程中（汇合至第（D）21天），或仅在早期分化（汇合至第13 -15天）或晚期分化（第13 -15天至第21天）期间，将细胞与0-8 μ M DFOM孵育。通过测量转铁蛋白受体和铁蛋白轻链和重链的基因和蛋白质表达的改变来确定细胞内铁状态的变化。通过测量已知在分化过程中上调的基因的表达，分析矿化表面积的百分比，并在培养结束时计数多层骨结节的数量来监测成骨细胞表型的发育。结果表明，在整个分化过程中，用8 μ M DFOM处理改变了中期分化（D13-15）的铁调节基因和蛋白质，其模式与铁缺乏一致，伴随着成骨细胞表型基因的下调，特别是骨钙素。此外，与对照相比，在整个分化过程中用8 μ M DFOM处理的威尔斯孔中，碱性磷酸酶染色较低，到D21时矿化表面积减少约70%（p < 0.05）。在仅在早期分化期间处理的细胞中，骨钙素和碱性磷酸酶mRNA的下调（p < 0.05）和矿化抑制（p < 0.05）在D21时也很明显。相比之下，在晚期分化过程中的治疗并没有改变D21的成骨细胞的结果。总之，铁是正常成骨细胞表型发育所必需的，早期而不是晚期分化事件可能对铁的可用性更敏感。(C)2010爱思唯尔公司All rights reserved.
There are few studies describing the extent to which low iron status affects osteoblastogenesis, despite evidence that iron deficiency produces adverse effects on bone density. The purpose of this study was to evaluate alterations in intracellular iron status by measuring iron-regulated gene and protein expression and to describe development of osteoblast phenotype in primary cells treated with iron chelator deferoxamine (DFOM) during differentiation. Using the well-described fetal rat calvaria model, cells were incubated with 0-8 mu M DFOM throughout differentiation (confluence to day (D) 21), or only during early differentiation (confluence to D13-15) or late differentiation (D13-15 to D21). Changes in intracellular iron status were determined by measuring alterations in gene and protein expression of transferrin receptor and ferritin light chain and heavy chain. Development of osteoblast phenotype was monitored by measuring expression of genes that are known to be up-regulated during differentiation, analyzing the percentage of mineralized surface area, and counting the number of multi-layered bone nodules at the end of culture. Results indicate that treatment throughout differentiation with 8 mu M DFOM alters iron-regulated genes and proteins by mid-differentiation (D13-15) in a pattern consistent with iron deficiency with concomitant down-regulation of osteoblast phenotype genes, especially osteocalcin. Additionally, alkaline phosphatase staining was lower and there was about 70% less mineralized surface area (p < 0.05) by D21 in wells treated throughout differentiation with 8 mu M DFOM compared to control. Down-regulation of osteocalcin and alkaline phosphatase mRNA (p < 0.05) and suppressed mineralization (p < 0.05) was also evident at D21 in cells treated only during early differentiation. In contrast, treatment during late differentiation did not alter osteoblastic outcomes by D21. In conclusion, it appears that iron is required for normal osteoblast phenotype development, and that early rather than late differentiation events may be more sensitive to iron availability. (C) 2010 Elsevier Inc. All rights reserved.