Watson R W, Redmond H P, Wang J H, Bouchier-Hayes D
Department of Surgery, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin.
J Leukoc Biol. 1996 Nov;60(5):625-32. doi: 10.1002/jlb.60.5.625.
Apoptosis is a distinct mechanism by which eukaryotic cells die. Factors governing the induction of polymorphonuclear leukocyte (PMN) apoptosis should be important in understanding resolution of acute inflammation. The mechanisms for induction of PMN apoptosis remain uncertain; however, oxidative stress has been suggested. The aims of this study were to determine whether reactive oxygen intermediates play a role in PMN apoptosis and to investigate inhibition of this process by selective use of antioxidants. PMN were isolated from 10 healthy volunteers. PMN (1 x 10(6) PMN/mL) were cultured in 40, 80, and 160 microM of arsenite for 2, 6, 12, 18, and 24 h. Apoptosis was assessed qualitatively by morphology and gel electrophoresis and quantitatively by CD16 receptor expression and propidium iodide DNA staining. There was a significant (P < 0.05) increase in the rate of apoptosis on incubation with arsenite (80 and 160 microM). To investigate the mechanism of this process, intracellular respiratory burst activity was measured following arsenite culture. We found that arsenite-induced PMN apoptosis correlated with an increase in intracellular respiratory burst. To further investigate the role of oxidative injury in inducing apoptosis, the antioxidants catalase, dimethyl sulfoxide (DMSO), glutathione (GSH), N-acetylcysteine (NAC), and taurine were investigated and we demonstrated that GSH, NAC, and taurine were significantly protective against arsenite-induced apoptosis. However, catalase and DMSO failed to induce protection. This study demonstrates that arsenite induces PMN apoptosis through an oxygen-dependent mechanism that can be prevented through selective antioxidants.
细胞凋亡是真核细胞死亡的一种独特机制。控制多形核白细胞（PMN）凋亡诱导的因素对于理解急性炎症的消退应该很重要。PMN凋亡诱导的机制尚不确定；然而，有人提出氧化应激与之有关。本研究的目的是确定活性氧中间体是否在PMN凋亡中起作用，并通过选择性使用抗氧化剂来研究对这一过程的抑制作用。从10名健康志愿者中分离出PMN。将PMN（1×10⁶个PMN/mL）在40、80和160微摩尔的亚砷酸盐中培养2、6、12、18和24小时。通过形态学和凝胶电泳定性评估凋亡，并通过CD16受体表达和碘化丙啶DNA染色定量评估凋亡。与亚砷酸盐（80和160微摩尔）孵育后，凋亡率有显著（P<0.05）增加。为了研究这一过程的机制，在亚砷酸盐培养后测量细胞内呼吸爆发活性。我们发现亚砷酸盐诱导的PMN凋亡与细胞内呼吸爆发的增加相关。为了进一步研究氧化损伤在诱导凋亡中的作用，研究了抗氧化剂过氧化氢酶、二甲基亚砜（DMSO）、谷胱甘肽（GSH）、N-乙酰半胱氨酸（NAC）和牛磺酸，我们证明GSH、NAC和牛磺酸对亚砷酸盐诱导的凋亡有显著保护作用。然而，过氧化氢酶和DMSO未能起到保护作用。本研究表明，亚砷酸盐通过一种氧依赖机制诱导PMN凋亡，这种机制可以通过选择性抗氧化剂来预防。
