番茄E8启动子乙烯应答元件克隆及DNA序列分析

E8启动子是常用的番茄果实特异表达启动子之一，是指番茄E8基因5’侧翼近2．2kb的DNA序列。前人的研究表明，E8基因5’侧翼-2181～-1088区段的删除使E8基因表达量大幅度下降(仅为完整E8启动子的1／10)，同时该区段还是E8基因对乙烯应答的充分必要区域；这说明了该区段是E8基因表达调控的重要元件。

Cloning and DNA Sequence Analysis of Element Responsive to Ethylene in E8 Promoter of the Tomato

AIM: To investigate the effects of octreotide (Oct) on the proliferation and extracellular matrix (ECM) synthesis in hepatic stellate cells (HSCs). METHODS: HSCs were isolated from normal male Sprague-Dawley rat liver by a combination of pronase-collagenase perfusion and density gradient centrifugation. The concentration of 2.5 μg/L transforming growth factor β1 (TGFβ1) was used in all the experiment settings. Oct at concentrations of 0.01 mg/L, 0.1 mg/L, 1 mg/L and 10 mg/L, respectively, or 0.01 mg/L Oct + TGFβ1, 0.1 mg/L Oct+TGFβ1, 1 mg/L Oct+TGFβ1, 10 mg/L Oct+TGFβ1 were respectively added to the cultured HSCs. Effects of Oct on HSC proliferation and ECM synthesis were respectively determined by MTT method, [³H]-TdR and [³H]-proline incorporation, or radioimmunoassay. RESULTS: Oct inhibited MTT intake by cultured hepatic stellate cells and down-regulated [³H]-TdR incorporation, compared with control group. The concentrations of hyaluronic acid, laminin, collagen type IV in the culture supernatant and [³H]-proline incorporation in HSCs were decreased by Oct. TGFβ1 obviously up-regulated proliferation and ECM synthesis in cultured HSCs, and Oct significantly blocked these actions. CONCLUSION: Oct inhibited proliferation and ECM synthesis in cultured HSCs, and elicited the effects of anti-hepatofibrogenesis.