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低氧暴露对大鼠骨骼肌L6细胞铁代谢的影响

李海洲, 刘玉倩^*, 王海涛, 刘树欣, 赵斌, 杨杰

河北师范大学体育学院，石家庄 050024

摘要

本文旨在研究低氧暴露对骨骼肌细胞铁代谢的影响。培养大鼠骨骼肌L6细胞，随机分成3组，分别低氧(1% O2)暴露0、12和24 h。采用同位素55Fe示踪法测定细胞铁摄取和铁释放能力的变化；用流式细胞仪检测细胞内可变铁池(labile iron pool, LIP)；应用蛋白免疫印迹检测转铁蛋白受体1 (transferrin receptor 1, TfR1)、二价金属离子转运体(divalent metal transporter 1, DMT1)、膜铁转运蛋白1 (ferroportin 1, FPN1)和低氧诱导因子1 (hypoxia-inducible transcription factor-1, HIF-1)的变化。结果显示，与0 h低氧暴露组相比，12 h低氧暴露组细胞的铁摄取能力明显升高(P < 0.05)，铁释放能力显著降低(P < 0.01)，LIP明显升高(P < 0.05)。24 h低氧暴露组肌细胞铁摄取、铁释放能力及LIP均明显低于0 h和12 h低氧暴露组(P < 0.05 或P < 0.01)。与0 h低氧暴露组比较，12 h低氧暴露组HIF-1、DMT1 (IRE)、DMT1 (non-IRE)和TfR1表达显著升高(P < 0.05 或P < 0.01)，而FPN1表达则显著降低(P < 0.01)；24 h低氧暴露组DMT1 (IRE)、DMT1 (non-IRE) 和FPN1表达均低于0和12 h低氧暴露组(P < 0.01)，但TfR1表达却显著增加(P < 0.05或P < 0.01)。以上结果提示，低氧对骨骼肌铁代谢的影响与暴露时间密切相关，一定时间的低氧暴露可以提高肌细胞的铁摄取能力，降低铁释放，增加细胞内的铁含量，而长时间的低氧暴露会引起细胞铁代谢紊乱。

关键词： 低氧暴露; L6细胞; 低氧诱导因子1; 铁

分类号：Q74

[Effects of hypoxia on iron metabolism of rat L6 skeletal muscle cells.] [Article in Chinese]

LI Hai-Zhou, LIU Yu-Qian^*, WANG Hai-Tao, LIU Shu-Xin, ZHAO Bin, YANG Jie

Department of Physical Education, Hebei Normal University, Shijiazhuang 050024, China

Abstract

The present study was aimed to investigate the effects of hypoxia on iron metabolism of skeletal muscle. Rat L6 skeletal muscle cells were randomly divided into three groups which were exposed to hypoxia (1% O2) for 0, 12, 24 h, respectively. Iron isotope tracing method was used to determine iron uptake and release. Iron content of labile iron pool (LIP) was investigated by flow cytometry, and the expressions of transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), ferroportin 1 (FPN1), hypoxia-inducible transcription factor-1 (HIF-1) in L6 cells were observed by Western blot. The results showed that, compared with 0-hour hypoxia group, 12-hour hypoxia group exhibited significantly increased iron uptake and LIP (P < 0.05), as well as decreased iron release (P < 0.01). Not only iron uptake and release, but also LIP in 24-hour hypoxia group were significantly decreased, compared with those in 0- and 12-hour hypoxia groups (P < 0.01). The expressions of HIF-1, DMT1 (IRE), DMT1 (non-IRE) and TfR1 in 12-hour hypoxia group were significantly increased compared with those in 0-hour hypoxia group (P < 0.01). On the contrary, the expressions of DMT1 (IRE), DMT1 (non-IRE) and FPN1 in 24-hour hypoxia group were significantly decreased compared with those in the other two groups. However, TfR1 expression in 24-hour hypoxia was higher than those in 0- and 12-hour hypoxia groups (P < 0.05 or P < 0.01). These results suggest hypoxia plays an important role in iron metabolism of skeletal muscle cells. Moderate hypoxia can increase iron uptake and decrease iron release, resulting in higher LIP, but a prolonged hypoxia induces a disordered iron metabolism of skeletal cells.

Key words: hypoxia; L6 cells; hypoxia-inducible transcription factor-1; iron

收稿日期：2011-02-25　　录用日期：2011-05-04

通讯作者：刘玉倩　　E-mail: yuqianht@126.com

引用本文：

李海洲, 刘玉倩, 王海涛, 刘树欣, 赵斌, 杨杰. 低氧暴露对大鼠骨骼肌L6细胞铁代谢的影响[J]. 生理学报 2011; 63 (4): 347-352.

LI Hai-Zhou, LIU Yu-Qian, WANG Hai-Tao, LIU Shu-Xin, ZHAO Bin, YANG Jie. [Effects of hypoxia on iron metabolism of rat L6 skeletal muscle cells.] [Article in Chinese]. Acta Physiol Sin 2011; 63 (4): 347-352 (in Chinese with English abstract).