Zhao Jing-jing, Zhao Long-feng, Yang Hui, Zhang Li
Department of Infectious Disease, the First Hospital of Shanxi Medical University, Taiyuan 030001, China.
Zhonghua Gan Zang Bing Za Zhi. 2013 Mar;21(3):218-21.
To investigate the effects of peroxisome proliferator activated receptor-alpha (PPAR-a) activation on oleic acid (OA)-induced steatosis and hepatic expression of heme oxygenase-1 (HO-1) using an in vitro cell model system.
A steatosis human hepatocyte in vitro model system was established by treating HepG2 cells with 0.2 mmol/L of oleic acid for 24 hours. The steatosis cells were then divided into four groups for an additional 24 hours of treatment with 0.2 mmol/L of oleic acid alone (model control group) or with 5, 10 or 50 pnol/L of fenofibrate (FF, a selective PPAR-a agonist; experimental groups). Untreated HepG2 cells served as non-steatosis controls. Effect of PPAR-a activation on fat accumulation was detected by Oil Red O staining and on intracellular triglyceride (TG) levels by enzymatic assay. mRNA and protein expression of PPAR-alpha and HO-1 were quantified by real-time PCR and immunocytochemistry, respectively. One-way ANOVA and the LSD t-test were used for between-group comparisons, and correlation analysis was performed with the Pearson's correlation coefficient.
The steatosis model control cells showed significantly increased TG deposition (379.98 +/- 23.19 mg/g protein, vs. non-steatosis controls F = 148.56, P< 0.01), significantly decreased mRNA and protein expression of PPAR-alpha (0.42 +/- 0.38,F= 177.64,P< 0.01 and 0.47 +/- 0.14, F= 120.76,P< 0.01) and HO-1 (0.36 +/- 0.66, F= 74.77,P< 0.01 and 0.26 +/- 0.10,F= 119.90,P<0.01). FF (5, 10 and 50 micromol/L) inhibited the steatosis induced by OA in a concentration-dependent manner (294.00 +/- 19.80, 250.33 +/- 9.96, and 196.99 +/- 9.14, F = 148.56, P <0.01) and increased the mRNA and protein expression of PPAR-alpha (0.55 +/- 0.65, 0.85 +/- 0.61, and 1.31 +/- 0.36,F= 177.64,P< 0.01; 0.82 + 0.11, 1.31 +/- 0.16, and 1.75 +/- 0.13, F= 120.76,P <0.01) and HO-1 (0.62 +/- 0.05, 0.84 +/- 0.07, and 1.30 +/- 0.11,F= 74.77,P <0.01; 0.44 +/- 0.08, 0.81 +/- 0.08, 1.20 +/- 0.10,F= 119.90,P< 0.01).
Activation of PPAR-a prevents OA-induced steatosis in HepG2 cells, and HO-1 may function as a downstream effector of this mechanism.
使用体外细胞模型系统，研究过氧化物酶体增殖物激活受体α（PPAR-α）激活对油酸（OA）诱导的脂肪变性及血红素加氧酶-1（HO-1）肝脏表达的影响。
通过用0.2 mmol/L油酸处理HepG2细胞24小时，建立体外脂肪变性人肝细胞模型系统。然后将脂肪变性细胞分为四组，再分别用0.2 mmol/L油酸单独处理24小时（模型对照组），或用5、10或50 μmol/L非诺贝特（FF，一种选择性PPAR-α激动剂；实验组）处理。未处理的HepG2细胞作为非脂肪变性对照。通过油红O染色检测PPAR-α激活对脂肪积累的影响，通过酶法检测细胞内甘油三酯（TG）水平。分别通过实时PCR和免疫细胞化学法定量PPAR-α和HO-1的mRNA和蛋白表达。采用单因素方差分析和LSD t检验进行组间比较，并使用Pearson相关系数进行相关分析。
脂肪变性模型对照细胞显示TG沉积显著增加（379.98±23.19 mg/g蛋白，与非脂肪变性对照相比F = 148.56，P<0.01），PPAR-α的mRNA和蛋白表达显著降低（0.42±0.38，F = 177.64，P<0.01和0.47±0.14，F = 120.76，P<0.01）以及HO-1（0.36±0.66，F = 74.77，P<0.01和0.26±0.10，F = 119.90，P<0.01）。FF（5、10和50 μmol/L）以浓度依赖性方式抑制OA诱导的脂肪变性（294.00±19.80、250.33±9.96和
