Department of Gastroenterology and Hepatology, Guangzhou Institute of Digestive Disease, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, 510180, China.
J Cell Biochem. 2014 May;115(5):839-46. doi: 10.1002/jcb.24725.
Accumulating evidence supports the role of miR-122 in fatty liver disease. We investigated miR-122 expression in a steatotic hepatocyte model, the effect of miR-122 over-expression and inhibition in the pathogenesis. Human hepatic cell line L02 was induced with oleic acid to establish the steatotic hepatocyte model. Intracellular lipid content was observed with laser scanning confocal microscope (LSCM), and triglyceride content was determined with kits. Total RNA was extracted and reversely transcribed into cDNA. miR-122 expression was measured using qRT-PCR. Subsequently, miR-122 mimic and miR-122 inhibitor were transfected into steatotic hepatocytes to observe their effect on intracellular lipid content. The lipid fluorescence intensity and triglyceride content within the steatotic hepatocytes were significantly higher than those in normal control (860.01 ± 26.52 vs. 257.77 ± 29.69 and 3.47 ± 0.12 vs. 1.85 ± 0.02 at 24 h) (P < 0.01). miR-122 expression in steatotic hepatocytes was down-regulated compared with that in control (2-ΔCt value: 0.0286 ± 0.0078 vs. 0.0075 ± 0.0012) (P ≪ 0.01). After transfection, miR-122 expression (2-ΔCt value) in the miR-122 mimic group increased 2.96-fold compared with that in control, and its lipid fluorescence intensity was significantly lower than that in control (790.92 ± 46.72 vs. 1,022.16 ± 49.66) (P < 0.01). Nevertheless, miR-122 expression decreased 3.45-fold in the miR-122 inhibitor group compared with that in control, and its fluorescence intensity was significantly higher than that in control (1,386.49 ± 40.34 vs 1,022.16 ± 49.66)(P ≪ 0.01). We concluded that miR-122 was down-regulated in steatotic hepatocytes model. The pathogenesis of hepatocyte steatosis was enhanced by miR-122 mimic and reduced with miR-122 inhibitor.
越来越多的证据支持 miR-122 在脂肪性肝病中的作用。我们研究了 steatotic 肝细胞模型中的 miR-122 表达，以及 miR-122 过表达和抑制在发病机制中的作用。用人肝细胞系 L02 用油酸诱导建立 steatotic 肝细胞模型。用激光扫描共聚焦显微镜（LSCM）观察细胞内脂质含量，用试剂盒测定甘油三酯含量。提取总 RNA 并逆转录为 cDNA。用 qRT-PCR 测量 miR-122 表达。随后，将 miR-122 模拟物和 miR-122 抑制剂转染至 steatotic 肝细胞，观察其对细胞内脂质含量的影响。与正常对照组相比，脂肪变性肝细胞的脂质荧光强度和甘油三酯含量明显升高（24 小时时为 860.01 ± 26.52 与 257.77 ± 29.69 和 3.47 ± 0.12 与 1.85 ± 0.02）（P < 0.01）。与对照组相比，脂肪变性肝细胞中的 miR-122 表达下调（2-ΔCt 值：0.0286 ± 0.0078 与 0.0075 ± 0.0012）（P < 0.01）。转染后，miR-122 模拟物组的 miR-122 表达（2-ΔCt 值）增加 2.96 倍，与对照组相比，其脂质荧光强度明显低于对照组（790.92 ± 46.72 与 1,022.16 ± 49.66）（P < 0.01）。然而，miR-122 抑制剂组的 miR-122 表达与对照组相比降低了 3.45 倍，其荧光强度明显高于对照组（1,386.49 ± 40.34 与 1,022.16 ± 49.66）（P < 0.01）。综上所述，miR-122 在 steatotic 肝细胞模型中下调。miR-122 模拟物增强了肝细胞脂肪变性的发病机制，而 miR-122 抑制剂则降低了其发病机制。
