摘要目的 研究L02肝细胞脂肪变模型中内质网应激状态下，干扰固醇调节元件结合蛋白(SREBP) -1c表达后肝细胞脂质代谢及肝细胞系统性炎症的变化情况及其意义。 方法 用油酸诱导L02肝细胞脂肪变，选用pSilencer 1.0-U6-4476质粒干扰SREBP-1c的表达，分为空白对照组、空质粒转染模型组及干扰质粒转染模型组。分别于0、24、48、72 h检测细胞炎症趋化因子配体(CCL)2和成纤维细胞生长因子(FGF) 21的mRNA和蛋白质的表达。组间比较用t检验，多个组间正态资料的比较用单因素方差分析。 结果 干扰SREBP-1c后，干扰质粒转染模型组较空质粒转染模型组细胞内脂肪滴数量明显减少，提示肝细胞脂肪变显著减轻。干扰质粒转染模型组CCL2基因在0、24、48、72h mRNA相对表达量分别为1.03±0.11、1.11±0.21、0.88±0.16、1.05±0.15，与空白对照组比较，P值均＞0.05，差异均无统计学意义。组内各时相点比较，P值均＞0.05，差异均无统计学意义。而对应的蛋白质表达量0、24、48、72h分别为1.19±0.15、1.07±0.18、0.48±0.14、0.05±0.24，低于空白对照组的4.15±0.18、4.09±0.21、3.91±0.13、4.06±0.12，两组比较，t值分别为2.78、3.67、4.10、4.89，P值均＜0.01，差异均有统计学意义。干扰质粒转染模型组组内各时相点比较,t值分别为1.11、2.25、3.17、1.01、3.27、3.51，P值均＜0.05，差异均有统计学意义。干扰质粒转染模型组FGF21基因mRNA相对表达量在0、24、48、72 h分别为1.01±0.08、0.91±0.22、0.98±0.20、1.02±0.12，与空白对照组比较，P值均＞0.05，差异均无统计学意义。干扰质粒转染模型组组内各时相点之间比较，t值分别为0.28、0.28、0.17、0.19、0.24、0.16，P值均＞0.05，差异均无统计学意义。而对应的蛋白质表达量下调趋势非常明显，0、24、48、72 h分别为0.81±0.05、0.66±0.12、0.58±0.08、0.19±0.13，与空白对照组的3.95±0.07、4.01±0.14、3.89±0.19、4.08±0.15比较，t值分别为3.21、3.78、4.54、5.17，P值均＜0.01，差异均有统计学意义。干扰质粒转染模型组组内各时相点比较，t值分别为1.08、1.76、3.54、1.24、4.21、3.79，P值均＜0.05，差异均有统计学意义。结论 SREBP-1c下调表达后能减轻内质网应激的后续效应，改善肝细胞脂质代谢，还可能通过CCL2通路减轻肝细胞内质网应激所致的炎症效应。

abstractsObjective To study the effect of SREBP-1c silencing on lipid metabolism and expression of inflammatory chemokines in a NAFLD model with endoplasmic reticulum stress. Method NAFLD model was established in L02 cells treated with oleic acid. SREBP-1c expression was inhibited using RNA interference with a pSilencer-1.0-U6-4476 vector. After transfection with pSilencer-1.0-U6-4476 or control vector for 0h, 24h, 48h and 72h, the extent of fatty degeneration was shown by Oil Red O staining. The mRNA and protein expression of inflammatory chemokine CCL2 and basic fibroblast growth factor-21 (FGF21) were determined by real time PCR and Western blot respectively. Results SREBP-lc silenced L02 cells showed fat droplets with smaller diameter and attenuated fatty deposition, as compared with control cells. The relative CCL2 mRN A levels in SREBP- 1 c silencing vector transfected L02 cells were 1.03 ± 0.11 for 0 h, 1.11 + 0.21 for 24 h, 0.88 + 0.16 for 48 h, and 1.05 + 0.15 for 72h, which showed no significant difference as compared with control cells (P ＞ 0.05, respectively). In addition, no difference was found between the different time points within the same group (P ＞ 0.05). However, CCL2 protein levels in SREBP- 1 c silenced cells were 1.19 + 0.15, 1.07 + 0.18, 0A8 + 0.14, and 0.05 + 0.24 after transfection for 0 h, 24h, 48h, and 72h respectively, which were significantly downregulated as compared to the control group (P ＜ 0.01). And CCL2 protein levels between different time points in SREBP-1c silenced cells were also distinct (P ＜0.01). The relative FGF21 mRNA levels in SREBP-1c silenced L-02 cells were 1.01 + 0.08, 0.91 + 0.22, 0.98 + 0.20, and 1.02 ± 0.12 for 0h, 24h, 48h, and 72h respectively, which were not statistically different as compared with the corresponding control cells. Statistic difference of FGF21 mRNA levels in SREBP-1c knockdown cells of different time points was not found (P＞ 0.05). In striking contrast, robust downregualtion of FGF21 protein in SREBP-lc silenced cells was observed, with 0.81 + 0.05, 0.66 + 0.12, 0.58 + 0.08 and 0.19 + 0.13 after transfection for 0 h, 24h, 48h and 72 h respectively, as compared to control group (P ＜ 0.01). And differences in FGF2 1 protein level between different time points in SREBP-1c silenced cells were also demonstrated (P＜0.01). Conclusion SREBP1c knockdown attenuated fatty deposition in oleic acid treated L02 cells. In addition, silencing of SREBP-1c expression reduced expressions of CCL2 and FGF21 proteins posttranscriptionally, which may play a role in endoplasmic reticulum stress induced inflammatory response in NAFLD.