Lelli J L, Becks L L, Dabrowska M I, Hinshaw D B
Department of Surgery, University of Michigan Medical School, Ann Arbor, USA.
Free Radic Biol Med. 1998 Oct;25(6):694-702. doi: 10.1016/s0891-5849(98)00107-5.
Cell death due to necrosis results in acute inflammation, while death by apoptosis generally does not. The effect of adenosine triphosphate (ATP) on the pattern of cell death induced by oxidants was examined in bovine endothelial cells. ATP levels were altered by hydrogen peroxide (H2O2), glutamine (Gln), and metabolic inhibition (MI), to determine if necrosis can be shifted to apoptosis during oxidant injury. The form of cell death was determined by fluorescence microscopic techniques and the pattern of DNA degradation on agarose gels. ATP levels were measured using the luciferase-luciferin assay. Apoptosis occurred with 100 microM H2O2 without an alteration in ATP levels. ATP was significantly lowered with 5 mM H2O2, and necrosis occurred. MI, in combination with 100 microM H2O2, decreased ATP and resulted in necrosis. MI alone, however, did not cause cell death. Gln partially restored ATP levels in cells injured with 5 mM H2O2 and resulted in a significant increase in apoptosis. DNA laddering on agarose gels confirmed the apoptotic changes seen by fluorescence microscopy. In summary, a threshold level of ATP 25% of basal levels is required for apoptosis to proceed after oxidant stress, otherwise necrosis occurs. Agents like glutamine that enhance ATP levels in oxidant-stressed cells may be potent means of shifting cell death during inflammation to the noninflammatory form of death--apoptosis.
坏死导致的细胞死亡会引发急性炎症，而凋亡导致的细胞死亡通常不会。在牛内皮细胞中研究了三磷酸腺苷（ATP）对氧化剂诱导的细胞死亡模式的影响。用过氧化氢（H2O2）、谷氨酰胺（Gln）和代谢抑制（MI）改变ATP水平，以确定在氧化剂损伤期间坏死是否可转变为凋亡。通过荧光显微镜技术和琼脂糖凝胶上DNA降解模式确定细胞死亡形式。使用荧光素酶 - 荧光素测定法测量ATP水平。100微摩尔H2O2处理时发生凋亡且ATP水平无变化。5毫摩尔H2O2处理使ATP显著降低，发生坏死。MI与100微摩尔H2O2联合使用会降低ATP并导致坏死。然而，单独的MI不会导致细胞死亡。Gln可部分恢复5毫摩尔H2O2损伤细胞中的ATP水平，并导致凋亡显著增加。琼脂糖凝胶上的DNA梯状条带证实了荧光显微镜下观察到的凋亡变化。总之，氧化剂应激后凋亡发生需要ATP达到基础水平的25%这一阈值，否则发生坏死。像谷氨酰胺这样能提高氧化剂应激细胞中ATP水平的物质，可能是在炎症期间将细胞死亡转变为非炎症性死亡形式——凋亡的有效手段。
