L-谷氨酰胺在镉致HK-2细胞损伤中的作用初探  

The role of L-glutamine in renal epithelial cell under cadmium treatment

作　　者：吴仕漩 朱盼[2] 赵敏[2] 谭剑斌[2] 李欣[2] 黄芮[2] 梁旭霞[2] 高燕红[2] 杨杏芬[1,2] 

机构地区：[1]中山大学公共卫生学院,广东广州510080 [2]广东省疾病预防控制中心

出　　处：《毒理学杂志》2016年第2期113-117,共5页Journal of Toxicology

基　　金：国家自然科学基金(81273102);卫生公益性行业科研项目(201302005);广东省医学科学技术研究基金(A2015060)

摘　　要：目的探讨谷氨酰胺在镉致肾细胞损伤过程中发挥的作用,为深入了解镉毒性机制提供科学依据。方法体外培养人肾近端小管上皮细胞系HK-2细胞,采用1、2、4、8、16、32、64和128μmol/L剂量氯化镉染毒处理24 h,观察细胞存活率（MTT法）和乳酸脱氢酶漏出水平（全自动生化仪测定）,检测细胞培养上清中谷氨酰胺水平（气相色谱-质谱联用法）和谷氨酰转肽酶含量（全自动生化仪测定）,并观察线粒体和胞浆中谷氨酰胺合成酶蛋白表达水平的变化（Western blot法）。结果氯化镉对HK-2细胞的半数抑制率浓度为40μmol/L;64和128μmol/L剂量组LDH漏出增多,与对照组相比,差异具有统计学意义（P〈0.01）;随染毒剂量增加谷氨酰胺含量呈上升趋势,与对照组比较4-128μmol/L剂量组差异具有统计学意义（P〈0.05）,且谷氨酰胺与氯化镉具有良好的剂量依赖关系。谷氨酰转肽酶从16μmol/L剂量组起增加,与对照组相比差异具有统计学意义（P〈0.01）。线粒体内谷氨酰胺合成酶蛋白表达水平随氯化镉剂量的增加出现降低现象,而胞浆中呈现升高趋势。结论在氯化镉处理人肾近端小管上皮细胞HK-2细胞24 h出现毒性损伤改变过程中,谷氨酰胺及其生物合成代谢关键分子谷氨酰转肽酶和谷氨酰胺合成酶均发生改变,提示谷氨酰胺可能在镉致肾损伤过程中发挥作用,值得进一步深入探究。Objective To explore the role of L-glutamine in renal epithelial cell under cadmium treatment. Methods HK-2 cells were treated with CdCl2 in 1,2,4,8,16,32,64,128 μmol/L for 24 h. MTT colorimetry test was used to detect the survival state of HK-2 cells. LDH and GGT values in culture supernatant were analyzed by automatic biochemical meter, while glutamine content was quantified by gas chromatography-mass spectroscopy （GC-MS）. The protein expression of glutamine synthetase in mitochondria and cytoplasm was confirmed by Western blot. Results CdCl2 could dose-dependently suppress the viability of HK-2 cells and the half maximal inhibitory concentration was 40 μmol/L. LDH levels in both 64 and 128 μmol/L groups were significantly higher than the control group （P 〈0. 01 ）. Glutamine content in supernatant raised with the increasing CdC12 dose, and the differences between the control and 4 -128 μmol/L groups were statistically significant （P 〈 0.05）. Compared with control group, the GGT level in supernatant in 16 -128 μmol/L groups were significantly increased, which were dose-dependently. Glutamine synthetase expressions were enhanced dose-dependently in mitochondria while weakened in cytoplasm. Conclusions CdCl2 could induced both the change of glutamine content and the key molecules in its anabolism process in HK-2 cells under cadmium treatment, indicating that glutamine may play an important role in kidney injury induced by cadmium.

关 键 词：镉 谷氨酰胺 谷氨酰胺合成酶 谷氨酰转肽酶 线粒体 

分 类 号：R994.6[医药卫生—毒理学]