Pretreatment with inducers of ER molecular chaperones protects epithelial cells subjected to ATP depletion
Pretreatment with inducers of ER molecular chaperones protects epithelial cells subjected to ATP depletion
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DOI：
10.1152/ajprenal.1999.277.2.f211
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发表时间：
1999-08-01
影响因子：
4.2
通讯作者：
Nigam, SK
中科院分区：
文献类型：
--
作者：
Bush, KT;George, SK;Nigam, SK
我们研究了内质网（ER）分子伴侣在肾缺血培养细胞模型中的潜在细胞保护作用。Madin-Darby犬肾（MDCK）细胞用衣霉素（ER诱导剂，但不是胞质分子伴侣）预处理12-16小时，然后6小时的ATP消耗。在对照组和衣霉素处理的细胞中均观察到细胞ATP的快速和严重消耗。台盼蓝拒染试验表明，与未经预处理的对照组相比，经衣霉素预处理的MDCK细胞可减少ATP耗竭诱导的细胞损伤，减少幅度接近80%。在用另一种ER分子伴侣诱导剂（即，A23187）。例如，发现与未处理的对照相比，A23187将乳酸脱氢酶释放减少了约50%，而E-64（一种可能影响ER中某些蛋白质降解的半胱氨酸蛋白酶抑制剂）对细胞损伤几乎没有影响或没有影响。此外，荧光测定证实了ATP耗竭后细胞损伤的显著减少（衣霉素预处理的细胞中减少高达80%）。总之，这些发现与ER分子伴侣的诱导导致在面对ATP耗竭时获得细胞保护的概念一致。然而，放线菌酮抑制蛋白质翻译被发现只部分减弱所观察到的细胞保护作用，提高了其他的可能性，尚未确定，非蛋白质合成依赖性机制也可能在所观察到的细胞保护中发挥作用。
We have investigated the potential cytoprotective role of endoplasmic reticulum (ER) molecular chaperones in a cultured cell model of renal ischemia. Madin-Darby canine kidney (MDCK) cells were pretreated with tunicamycin (an inducer of ER but not cytosolic molecular chaperones) for 12-16 h, followed by 6 h of ATP depletion. A rapid and severe depletion of cellular ATP was noted in both control and tunicamycin-treated cells. Trypan blue exclusion assays indicated that pretreatment of MDCK cells with tunicamycin reduced ATP depletion-induced cell damage by similar to 80% compared with nonpretreated controls. This apparent cytoprotective effect was also found following pretreatment with another inducer of ER molecular chaperones (i.e., A23187). For example, A23187 was found to reduce lactate dehydrogenase release by similar to 50% compared with untreated controls, whereas E-64, a cysteine protease inhibitor which may affect degradation of some proteins in the ER, had little or no effect on cell injury. Moreover, a fluorescent assay confirmed the marked reduction in cell damage following ATP depletion (up to 80% reduction in tunicamycin-pretreated cells). Together, these findings are consistent with the notion that induction of ER molecular chaperones leads to the acquisition of cytoprotection in the face of ATP depletion. However, inhibition of protein translation by cycloheximide was found to only partially attenuate the observed cytoprotective effect, raising the possibility that other, as yet to be identified, nonprotein synthesis-dependent mechanisms may also play a role in the observed cytoprotection.