中文摘要：

目的研究ZCWCC1蛋白在人L02肝细胞脂肪变性中的表达变化并探讨其机制。方法培养中加用500μmol/L的油酸处理L02肝细胞,建立肝细胞脂肪变性体外模型,采用油红染色评价脂质蓄积程度,采用免疫荧光及激光共聚焦显微镜观察ZCWCC1蛋白在L02肝细胞脂肪变性时的表达改变,以Western blot对其进行半定量评价,并使用赖氨酸蛋白酶抑制剂N-乙基马来酰亚胺（N-Ethylmaleimide,NEM）及蛋白酶体抑制剂MG132对ZCWCC1蛋白表达变化的相关机制进行初步探讨。结果油红染色及细胞甘油三酯含量测定证明L02肝细胞脂肪变性体外模型成功建立,激光共聚焦显微镜观察发现ZCWCC1蛋白主要定位在胞核内,其荧光信号随油酸诱导时间延长而减弱,Western blot检测结果显示,ZCWCC1表达水平也随油酸诱导时间延长（0、3、6、12、24、48 h）而降低[（56 283±303）、（56 753±539）、（55 561±996）、（56 257±326）、（48 339±712）、（43 022±2 198）,P〈0.01]。NEM处理可使ZCWCC1降解增加,MG132处理可逆转ZCWCC1在L02肝细胞脂肪变性中的下降趋势。结论 ZCWCC1蛋白在L02肝细胞的脂肪变性过程中表达下降,可能与泛素-蛋白酶体途径有关。

英文摘要：

Objective To determine the expression profile of ZCWCC1 （Zinc-finger CW-type coiled-coil protein 1 ） protein in the process of steatosis of immortalized hepatocyte cell line L02 （ hereinafter referred to as L02 cells）. Methods L02 cells were cultured in the medium containing 500 μmol/L oleic acid to induce steatosis, then confirmed by oil red 0 staining. Immunofluorescence assay and fluorescent confocal microscopy were employed to observe the protein levels of ZCWCC1 during induction of steatosis, and Western blotting was used to semi-quantify the results. Lysine protease inhibitor, N-Ethylmaleimide （NEM）, and proteasome inhibitor, MG132 were used to enhance or block the ubiquitin-proteasome pathway which is important for protein degradation. Results Oil red 0 staining and cellular triglyceride measurement confirmed the establishment of L02 steatosis model. Immunofluorescence assay and Western blot analysis indicated that ZCWCC1 was mainly located in the nucleus, and its expression level was descending during the induction of steatosis （56 283 ± 303, 56 753 ± 539, 55 561 ± 996, 56 257 ± 326, 48 339 ± 712, and 43 022 ±2 198 respectively in 0, 3,6, 12, 24 and 48 h after induction, P 〈0.01 ）. NEM treatment resulted in enhanced degradation of ZCWCC1 in the L02 cells, while MG132 inversed the descending tendency of ZCWCC1 during 1332 steatosis. Conclusion Protein level of ZCWCC1 was descending in the process of steatosis of hepatocyte L02 ceils, which might be relative to the ubiquitin-proteasome pathway.