目的探讨大鼠肝星状细胞(HSC)中,环磷酸腺苷(cAMP)反应元件结合蛋白-1(CREB-1)对转化生长因子β3(TGFβ3)的mRNA表达及启动子活I生的影响。方法将HSC分为CREB-1表达质粒转染组(C质粒组)、s氓NA—cREB-1转染组(s质粒组)、阴性对照质粒组(N质粒组)、Forskolin处理组(FSK组)、H-89处理组(H-89组)及空白对照组,并根据加或不加入外源性TGFD3重组蛋白将以上各组再分为(TGFD3+)组和(TGFD3-)组,实时荧光定量PCR法检测TGFβ3mRNA的表达。上述各组共转染PGL3妇sjc-TGFp3P(W质粒)或PGL3-basic-TGFB3P—mCRE(M质粒),以pRL-SV40为空白对照,荧光素酶报告基因分析法检测各组TGFD3启动子活性。双侧t检验进行组间数据比较。结果TGFD3mRNA表达结果显示,与N质粒(TGFp3-)组比较,s质粒(TGFp3-)组mRNA相对表达量降低至0.69fl:0.15(t=3.702,P〈0.05);与空白对照(TGFD3-)组比较,H-89(TGFD3-)组降低至0.57±0.08(t=9.490,P〈0.05);N质粒(TGFD3+)组与N质粒(TGFD3-)组、s质粒(TGFB3+)组与s质粒(TGFD3-)组、空白对照(TGFB3+)组与空白对照(TGFβ3-)组、H-89(TGFB3+)组与H-89(TGFD3-)组分别比较,差异均有统计学意义(t值分别为-7.404、-3.480、-2.831和-7.875,尸值均〈0.05)。荧光素酶报告基因分析结果显示,s+w质粒组、N+W质粒组、C+W质粒组的TGFB3启动子活性分别为0.062±0.013、0.122±0.011、0.165±0.016,C+W质粒组TGFB3活性较N+w质粒组组明显升高(t=-3.823,P〈0.05),s+w质粒组较N+w质粒组明显降低(t=5.853,P〈0.01)lH-89+W质粒组、空白对照+w质粒组、FSK+W质粒组TGFp3启动子活性分别为0.154士0.010、0.188士0.016、0.276±0.031,FSK+W质粒组的TGFB3启动子活性较空白对照+W质粒组明显升高(t=-4.419,P〈0.05),H-89+W质?
Objective To investigate the effects of cAMP-response element binding protein-1 (CREB- 1) on transforming growth factor-β3 (TGF β3) mRNA expression and promoter activity in hepatic stellate cells (HSCs). Methods Freshly isolated HSCs from rats were divided into six groups: CREB-1 expression plasmid transfected group (C), siRNA-CREB-1 plasmid transfected group (S), negative control group (N), forskolin treated group (F), H-89 treated group (H), and blank group (B). Rats in each group were further sub-divided according to whether (±) or not (-) they were exposed to exogenous TGF β3. TGF β3 mRNA expression was measured by real time quantitative PCR. HSCs of the C, S, N, F, H and B groups were transfected with the TGF β3 promoter luciferase reporter plasmid (PGL3-TGF β3-P; W group), the TGFβ3 promoter luciferase reporter plasmid with CRE mutation (PGL3-basic-TGF β3P-mCRE; M group) and the renilla luciferase control plasmid (pRL-SV40; control group). TGFβ3 promoter activity was assessed by luciferase reporter assays. Results Compared to NO, the TGF β3 m_RNA expression was reduced to 0.69 ± 0.15 in S(-) (P 〈 0.05) and increased to 4.68 ±2.76 in C(-) (P 〉 0.05). Compared to B(-), the TGFβ3 rnRNA expression was reduced to 0.57 ± 0.08 in H(-) (P 〈 0.05). The differences between N(±) and N(-), S(±) and S(-), B(±) and B(-), and H(±) and H(-) were all significant (P〈 0.05). The values of TGFβ3 promoter activity in S(W), N(W), and C(W) were 0.062 ± 0.013, 0.122 ±0.011, and 0.165 ± 0.016 (P〈0.05), but the changes of TGF 153 promoter activity in S(M), N(M), and C(M) were not significant (P〉0.05). The values of TGF β3 promoter activity in H(W), B(W), and F(W) were 0.154 ± 0.010, 0.188 ±0.016, and 0.276 ± 0.031 (P〈0.05), but the changes of TGFβ3 promoter activity in H(M), B(M), and F(M) were not significant ?