TEMPERATURE AND CELL-TYPE DEPENDENCY OF SULFIDE EFFECTS ON MITOCHONDRIAL RESPIRATION
TEMPERATURE AND CELL-TYPE DEPENDENCY OF SULFIDE EFFECTS ON MITOCHONDRIAL RESPIRATION
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DOI：
10.1097/shk.0b013e3182651fe6
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发表时间：
2012-10-01
期刊：
影响因子：
3.1
通讯作者：
Wagner, Katja
中科院分区：
文献类型：
--
作者：
Groeger, Michael;Matallo, Jose;Wagner, Katja
先前的研究表明，硫化物诱导的细胞色素c氧化酶（cCox）的抑制，因此，硫化物的代谢和毒性作用在低体温下不太明显。由于硫化物对炎症反应的温度依赖性影响仍然是一个有争议的问题，我们研究了不同温度对cCox过量容量和巨噬细胞衍生细胞系（AMJ 2-C11和RAW 264.7）中硫化物-泛醌氧化还原酶对线粒体硫化物氧化的影响。使用氧描记室，通过在25 ℃和37 ℃下用硫化物和不可代谢的cCox抑制剂叠氮化钠逐步滴定来测量线粒体呼吸的抑制。使用两种抑制剂中的后者，获得cCox的过剩容量。此外，我们通过测量抑制呼吸50%和90%所需的量以及暴露于100 ppm硫化氢24小时后细胞的活力来量化这些细胞耐受硫化物抑制的能力。在低滴定率下，AMJ 2-C11细胞而不是RAW 264.7细胞增加了它们耐受外源添加的硫化物的能力。这种效应在25摄氏度时甚至比在37摄氏度时更大。此外，只有AMJ 2-C11细胞在硫化物暴露24 h后仍存活。相比之下，仅在RAW 264.7电池中发现低温下cCox过剩容量增加。在巨噬细胞来源的细胞系中，cCox的过量容量和硫化物消除效率在低温下都可能增加。这些特性可能会改变硫化物在免疫细胞中的作用，并可能改变不同体温下硫化物暴露期间的炎症反应。
Previous studies suggest that sulfide-induced inhibition of cytochrome c oxidase (cCox) and, consequently, the metabolic and toxic effects of sulfide are less pronounced at low body temperature. Because the temperature-dependent effects of sulfide on the inflammatory response are still a matter of debate, we investigated the impact of varying temperature on the cCox excess capacity and the mitochondrial sulfide oxidation by the sulfide-ubiquinone oxidoreductase in macrophage-derived cell lines (AMJ2-C11 and RAW 264.7). Using an oxygraph chamber, the inhibition of mitochondrial respiration was measured by stepwise titrations with sulfide and the nonmetabolizable cCox inhibitor sodium azide at 25 degrees C and 37 degrees C. Using the latter of the two inhibitors, the excess capacity of the cCox was obtained. Furthermore, we quantified the capacity of these cells to withstand sulfide inhibition by measuring the amount required to inhibit respiration by 50% and 90% and the viability of the cells after 24-h exposure to 100 ppm of hydrogen sulfide. At low titration rates, the AMJ2-C11 cells, but not the RAW 264.7 cells, increased their capacity to withstand exogenously added sulfide. This effect was even greater at 25 degrees C than at 37 degrees C. Furthermore, only the AMJ2-C11 cells remained viable after sulfide exposure for 24 h. In contrast, only in the RAW 264.7 cells that an increase in cCox excess capacity was found at low temperatures. In macrophage-derived cell lines, both the excess capacity of cCox and the efficiency of sulfide elimination may increase at low temperatures. These properties may modify the effects of sulfide in immune cells and, potentially, the inflammatory response during sulfide exposure at different body temperatures.