Wang Jun, Qian Zhong-ming, Jiang Hong, Xie Junxia, Ke Ya
Laboratory of Iron Metabolism, Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Kowloon, Hong Kong, PR China.
Neurochem Int. 2005 Dec;47(7):514-7. doi: 10.1016/j.neuint.2005.02.008.
Divalent metal transporter 1 (DMT1) and transferrin receptor (TfR) might play a key role in non-transferrin-bound iron (NTBI) and transferrin-bound iron (Tf-Fe) uptake by neuronal cells. Recent studies demonstrated that nerve growth factor (NGF)-treated PC12 cells (the neuronal phenotype) have higher NTBI as well as Tf-Fe uptake compared with untreated cells (the undifferentiated cells). We speculated the increased NTBI and Tf-Fe uptake induced by NGF treatment might be associated with the increased expression of DMT1 and TfR. In this study, we investigated the effect of NGF treatment on DMT1 and TfR expression in PC12 cells. Contrary to our expectation, treatment with NGF induced a significant decrease rather than increase in DMT1+IRE, DMT1-IRE and TfR expression in the cells. The data demonstrate that the increase in iron uptake is not associated with the DMT1 and TfR in NGF-treated PC12 cells. The RT-PCR findings of no change in DMT1 mRNA plus our data suggest that regulation of DMT1 expression by NGF might be at the post-transcriptional level.
二价金属转运蛋白1（DMT1）和转铁蛋白受体（TfR）可能在神经元细胞摄取非转铁蛋白结合铁（NTBI）和转铁蛋白结合铁（Tf-Fe）过程中发挥关键作用。最近的研究表明，与未处理的细胞（未分化细胞）相比，经神经生长因子（NGF）处理的PC12细胞（神经元表型）具有更高的NTBI以及Tf-Fe摄取量。我们推测，NGF处理诱导的NTBI和Tf-Fe摄取增加可能与DMT1和TfR表达增加有关。在本研究中，我们调查了NGF处理对PC12细胞中DMT1和TfR表达的影响。与我们的预期相反，NGF处理导致细胞中DMT1+IRE、DMT1-IRE和TfR表达显著降低而非增加。数据表明，在经NGF处理的PC12细胞中，铁摄取增加与DMT1和TfR无关。DMT1 mRNA无变化的RT-PCR结果以及我们的数据表明，NGF对DMT1表达的调节可能在转录后水平。
