Extracellular thiol/disulfide redox state affects proliferation rate in a human colon carcinoma (Caco2) cell line
Extracellular thiol/disulfide redox state affects proliferation rate in a human colon carcinoma (Caco2) cell line
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DOI：
10.1016/s0891-5849(02)01081-x
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发表时间：
2002-12-01
影响因子：
7.4
通讯作者：
Jones, DP
中科院分区：
文献类型：
--
作者：
Jonas, CR;Ziegler, TR;Jones, DP
氧化还原机制在调节细胞生长方面发挥作用，血浆硫醇/二硫化物对的氧化还原状态在各种生理条件下都会发生变化，包括糖尿病、化疗和衰老。本研究旨在确定人血浆中细胞外硫醇/二硫代氧化还原状态(Eh)在0 mV至-150 mV范围内的系统性变化是否会改变培养细胞的增殖。实验是用人结肠癌细胞系(Caco 2)进行的，该细胞系在没有血清的情况下生长缓慢，对多肽生长因子的反应加快，细胞分裂速度加快。胞外氧化还原状态是通过不同浓度的半胱氨酸和半胱氨酸来建立的，根据半胱氨酸当量保持池大小不变。用5-溴-2-脱氧尿苷(BrdU)掺入法检测DNA合成，在氧化程度最高的胞外Eh(0 MV)处最低。掺入随着氧化还原状态的变化而增加，在最低值(-150 mV)时达到100%的高值。加入胰岛素样生长因子-1(IGF-1)或表皮生长因子(EGF)可增加氧化还原条件下(0~-80 mV)BrdU的掺入速率，但在-150 mV时无明显作用。细胞外E的变化对细胞内GSH无明显影响，在没有生长因子的情况下，细胞外的E值基本维持24小时，而IGF-1或EGF刺激细胞外氧化还原的变化与年轻健康个体血浆中半胱氨酸/半胱氨酸氧化还原的值相似。结果表明，细胞外的硫醇/二硫代氧化还原状态调节细胞的增殖速度，并且这种调控与生长因子信号的相互作用明显不依赖于细胞内的谷胱甘肽。(C)2002年爱思唯尔科学公司。
Redox mechanisms function in regulation of cell growth, and variation in redox state of plasma thiol/ disulfide couples occurs in various physiologic conditions, including diabetes, chemotherapy, and aging. The present study was designed to determine whether a systematic variation in extracellular thiol/disulfide redox state (Eh) over a range (0 mV to -150 mV) that occurs in human plasma altered proliferation of cultured cells. Experiments were performed with a human colon carcinoma cell line (Caco2), which grows slowly in the absence of serum and responds to peptide growth factors with increased rate of cell division. The extracellular redox states were established by, varying concentrations of cysteine and cystine, maintaining constant pool size in terms of cysteine equivalents. Incorporation of 5-bromo-2-deoxyuridine (BrdU) was used to measure DNA synthesis and was lowest at the most oxidized extracellular Eh (0 mV). Incorporation increased as a function of redox state, attaining a 100% higher value at the most reduced condition (- 150 mV). Addition of insulin-like growth factor-1 (IGF-1) or epidermal growth factor (EGF) increased the rate of BrdU incorporation at more oxidizing redox conditions (0 to - 80 mV) but had no effect at - 150 mV. Cellular GSH was not significantly affected by variation in extracellular E, In the absence of growth factors, extracellular E, values were largely maintained for 24 h. However, IGF-1 or EGF stimulated a change in extracellular redox to values similar to that for cysteine/cystine redox in plasma of young, healthy individuals. The results show that extracellular thiol/disulfide redox state modulates cell proliferation rate and that this control interacts with growth factor signaling apparently independently of cellular glutathione. (C) 2002 Elsevier Science Inc.