Stelmashook E V, Genrikhs E E, Kapkaeva M R, Zelenova E A, Isaev N K
Research Center of Neurology, Moscow, 125367, Russia.
Biochemistry (Mosc). 2017 Oct;82(10):1176-1182. doi: 10.1134/S0006297917100108.
Addition into the culture medium of the antioxidant N-acetylcysteine (NAC, 1 mM) in the presence of Cu2+ (0.0005-0.001 mM) induced intensive death of cultured rat cerebellar granule neurons, which was significantly decreased by the zinc ion chelator TPEN (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine). However, the combined action of NAC and Zn2+ did not induce destruction of the neurons. Measurement of the relative intracellular concentration of Zn2+ with the fluorescent probe FluoZin-3 AM or of free radical production using a CellROX Green showed that incubation of the culture for 4 h with Cu2+ and NAC induced an intensive increase in the fluorescence of CellROX Green but not of FluoZin-3. Probably, the protective effect of TPEN in this case could be mediated by its ability to chelate Cu2+. Incubation of cultures in a balanced salt solution in the presence of 0.01 mM Cu2+ caused neuronal death already after 1 h if the NAC concentration in the solution was within 0.005-0.05 mM. NAC at higher concentrations (0.1-1 mM) together with 0.01 mM Cu2+ did not cause the death of neurons. These data imply that the antioxidant NAC can be potentially harmful to neurons even in the presence of nanomolar concentrations of variable valence metals.
在存在Cu2+（0.0005 - 0.001 mM）的情况下，向培养基中添加抗氧化剂N - 乙酰半胱氨酸（NAC，1 mM）会诱导培养的大鼠小脑颗粒神经元大量死亡，而锌离子螯合剂TPEN（N，N，N'，N'-四（2 - 吡啶甲基）乙二胺）可显著降低这种死亡。然而，NAC和Zn2+的联合作用并未诱导神经元的破坏。用荧光探针FluoZin - 3 AM测量细胞内Zn2+的相对浓度，或使用CellROX Green测量自由基产生，结果表明，用Cu2+和NAC孵育培养物4小时会导致CellROX Green荧光强烈增加，但FluoZin - 3荧光未增加。在这种情况下，TPEN的保护作用可能是由其螯合Cu2+的能力介导的。如果溶液中NAC浓度在0.005 - 0.05 mM范围内，在含有0.01 mM Cu2+的平衡盐溶液中孵育培养物1小时后就会导致神经元死亡。较高浓度（0.1 - 1 mM）的NAC与0.01 mM Cu2+一起不会导致神经元死亡。这些数据表明，即使在存在纳摩尔浓度的可变价金属的情况下，抗氧化剂NAC对神经元也可能具有潜在危害。
