Following acute and chronic liver injury,hepatic stellate cells (HSCs) become activated to undergo a phenotypic transformation into myofibroblast-like cells and lose their retinol content,but the mechanisms of retinoi...Following acute and chronic liver injury,hepatic stellate cells (HSCs) become activated to undergo a phenotypic transformation into myofibroblast-like cells and lose their retinol content,but the mechanisms of retinoid loss and its potential roles in HSCs activation and liver fibrosis are not understood.The influence of retinoids on HSCs and hepatic fibrosis remains controversial.The purpose of this study was to evaluate the effects of all-trans retinoid acid (ATRA) on cell proliferation,mRNA expression of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)],profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),fibrolytic genes (MMP-3,MMP-13) and the upstream element (JNK and AP-1) in the rat hepatic stellate cell line (CFSC-2G).Cell proliferation was evaluated by measuring BrdU incorporation.The mRNA expression levels of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)],profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and fibrolytic genes (MMP-3,MMP-13) were quantitatively detected by using real-time PCR.The mRNA expression of JNK and AP-1 was quantified by RT-PCR.The results showed that ATRA inhibited HSCs proliferation and diminished the mRNA expression of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)] and profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and significantly stimulated the mRNA expression of MMP-3 and MMP-13 in HSCs by suppressing the mRNA expression of JNK and AP-1.These findings suggested that ATRA could inhibit proliferation and collagen production of HSCs via the suppression of active protein-1 and c-Jun N-terminal kinase signal,then decrease the mRNAs expression of profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and significantly induce the mRNA expression of MMP-3 and MMP-13.展开更多
为提高我国电动自行车厂家的市场竞争力,研制出一款新颖的智能型1∶1助力车.在详细阐述1∶1电动助力车的实现原理及其方案的基础上,提出采用经特殊设计的速度传感器和扭矩传感器采集人力脚踩速度和扭矩,并利用P IC 16C 712单片机作为信...为提高我国电动自行车厂家的市场竞争力,研制出一款新颖的智能型1∶1助力车.在详细阐述1∶1电动助力车的实现原理及其方案的基础上,提出采用经特殊设计的速度传感器和扭矩传感器采集人力脚踩速度和扭矩,并利用P IC 16C 712单片机作为信号处理与中心控制单元,以完成对人力脚踩输出功率的计算,并根据该功率的大小控制直流驱动电机的输出,实现真正意义上的1∶1助力.此外,为提高使用性能和安全性能,P IC 16C 712单片机还能够对该车的工作状况进行实时监测和控制.经测试表明:该车完全符合有关的1∶1技术标准,与同类车相比,该车在可靠性、使用性和性价比等方面呈现出明显的优势.展开更多
文摘Following acute and chronic liver injury,hepatic stellate cells (HSCs) become activated to undergo a phenotypic transformation into myofibroblast-like cells and lose their retinol content,but the mechanisms of retinoid loss and its potential roles in HSCs activation and liver fibrosis are not understood.The influence of retinoids on HSCs and hepatic fibrosis remains controversial.The purpose of this study was to evaluate the effects of all-trans retinoid acid (ATRA) on cell proliferation,mRNA expression of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)],profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),fibrolytic genes (MMP-3,MMP-13) and the upstream element (JNK and AP-1) in the rat hepatic stellate cell line (CFSC-2G).Cell proliferation was evaluated by measuring BrdU incorporation.The mRNA expression levels of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)],profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and fibrolytic genes (MMP-3,MMP-13) were quantitatively detected by using real-time PCR.The mRNA expression of JNK and AP-1 was quantified by RT-PCR.The results showed that ATRA inhibited HSCs proliferation and diminished the mRNA expression of collagen genes [procollagen α1 (Ⅰ),procollagen α1 (Ⅲ)] and profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and significantly stimulated the mRNA expression of MMP-3 and MMP-13 in HSCs by suppressing the mRNA expression of JNK and AP-1.These findings suggested that ATRA could inhibit proliferation and collagen production of HSCs via the suppression of active protein-1 and c-Jun N-terminal kinase signal,then decrease the mRNAs expression of profibrogenic genes (TGF-β 1,CTGF,MMP-2,TIMP-1,TIMP-2,PAI-1),and significantly induce the mRNA expression of MMP-3 and MMP-13.
文摘为提高我国电动自行车厂家的市场竞争力,研制出一款新颖的智能型1∶1助力车.在详细阐述1∶1电动助力车的实现原理及其方案的基础上,提出采用经特殊设计的速度传感器和扭矩传感器采集人力脚踩速度和扭矩,并利用P IC 16C 712单片机作为信号处理与中心控制单元,以完成对人力脚踩输出功率的计算,并根据该功率的大小控制直流驱动电机的输出,实现真正意义上的1∶1助力.此外,为提高使用性能和安全性能,P IC 16C 712单片机还能够对该车的工作状况进行实时监测和控制.经测试表明:该车完全符合有关的1∶1技术标准,与同类车相比,该车在可靠性、使用性和性价比等方面呈现出明显的优势.
