AIM: To analyse the influence of Smad7, antagonist of transforming growth factor (TGF)-β canonical signaling pathways on hepatic stellate cell (HSC) transdifferentia-tion in detail. METHODS: We systematically analyse...AIM: To analyse the influence of Smad7, antagonist of transforming growth factor (TGF)-β canonical signaling pathways on hepatic stellate cell (HSC) transdifferentia-tion in detail. METHODS: We systematically analysed genes regulated by TGF-β/Smad7 in activated HSCs by microarray analy-sis and validated the results using real time polymerase chain reaction and Western blotting analysis. RESULTS: We identif ied 100 known and unknown tar-gets underlying the regulation of Smad7 expression and delineated 8 gene ontology groups. Hk2, involved in glycolysis, was one of the most downregulated proteins, while BMP2, activator of the Smad1/5/8 pathway, was extremely upregulated by Smad7. However, BMP2 de-pendent Smad1 activation could be inhibited in vitro by Smad7 overexpression in HSCs. CONCLUSION: We conclude (1) the existence of a tight crosstalk of TGF-β and BMP2 pathways in HSCs and (2) a Smad7 dependently decreased sugar metabolism ameliorates HSC activation probably by energy with-drawal.展开更多
基金Supported by Deutsche Forschungsgemeinschaft DO373/6-1 and SFB TRR77,BMBF (HepatoSys), European Research Advisory Board and the Schlieben-Lange-Programm of the Ministerium für Wissenschaft, Forschung und Kunst of Baden-Württemberg and the Europflische Sozialfond
文摘AIM: To analyse the influence of Smad7, antagonist of transforming growth factor (TGF)-β canonical signaling pathways on hepatic stellate cell (HSC) transdifferentia-tion in detail. METHODS: We systematically analysed genes regulated by TGF-β/Smad7 in activated HSCs by microarray analy-sis and validated the results using real time polymerase chain reaction and Western blotting analysis. RESULTS: We identif ied 100 known and unknown tar-gets underlying the regulation of Smad7 expression and delineated 8 gene ontology groups. Hk2, involved in glycolysis, was one of the most downregulated proteins, while BMP2, activator of the Smad1/5/8 pathway, was extremely upregulated by Smad7. However, BMP2 de-pendent Smad1 activation could be inhibited in vitro by Smad7 overexpression in HSCs. CONCLUSION: We conclude (1) the existence of a tight crosstalk of TGF-β and BMP2 pathways in HSCs and (2) a Smad7 dependently decreased sugar metabolism ameliorates HSC activation probably by energy with-drawal.
文摘目的:探讨外源性转入并上调表达抑制性信号蛋白Sm ad7对TGF-β1作用下大鼠腹膜间皮细胞Sm ad2表达的影响。方法:通过脂质体介导的方法,将表达Sm ad7的重组质粒(PCDNA3-Sm ad7)转染培养的大鼠腹膜间皮细胞,分别培养于不同浓度TGF-β1培养液(0、1.25、2.5和10μg/L),用RT-PCR及W estern b lotting的方法检测不同时间(0、5、15、30、60和120 m in)Sm ad2、Sm ad7表达的水平。结果:正常间皮细胞Sm ad2 mRNA和蛋白在TGF-β1刺激后5 m in开始表达,呈时间依赖性,在30 m in达到高峰,而后逐渐减弱;Sm ad7 mRNA和蛋白也在TGF-β1刺激后5 m in可见表达,但此后逐渐减弱,30 m in达到最低,60 m in又开始逐渐增强。Sm ad2和Sm ad7mRNA和蛋白,随TGF-β1浓度的增高而表达增强。转染后大鼠腹膜间皮细胞可见Sm ad7 mRNA和蛋白表达显著上调,并可持续高表达。转染后的腹膜间皮细胞在TGF-β1刺激下,Sm ad2 mRNA及蛋白的表达均低下,刺激0、5、15、30、60和120 m in后Sm ad2 mRNA表达分别低33%、56%、67%、71%、63%和57%(P<0.05)。Sm ad2蛋白表达分别低78%、89%、89%、88%和76%(P<0.05)。结论:上调表达抑制性信号蛋白Sm ad7可显著抑制腹膜间皮细胞中受体调控信号蛋白Sm ad2的表达和活性,提示Sm ad7可能对TGF-β1起反向调控作用。
