Establishment of a reporter system for estimating activation of human hepatic stellate cells based on COL1A1 promoter and enhanced green fluorescent protein / 北京大学学报(医学版)

OBJECTIVE@#To establish a visual reporting system for evaluating the activity of collagen Ⅰ α 1 chain (COL1A1) gene promoter in immortalized human hepatic stellate cells, so as to estimate the activation status of the cells and provide a new cell model for the screening and study of anti-hepatic fibrosis drugs.@*METHODS@#The promoter sequence of human COL1A1 was amplified from the genomic DNA of human hepatocarcinoma cell line HepG2. Based on the pLVX-AcGFP1-N1 plasmid, the recombinant plasmid pLVX-COL1A1-enhanced green fluorescent protein (EGFP) was constructed, in which the enhanced green fluorescent protein gene expression was regulated by the COL1A1 promoter. The monoclonal cell line was acquired by stably transfecting pLVX-COL1A1-EGFP into the immortalized human hepatic stellate cell line LX-2 by the lentivirus packaging system and screening. The cell line was treated with transforming growth factor-β1 (TGF-β1) or co-treated with TGF-β1 and drugs with potential anti-hepatic fibrosis effects. The EGFP fluorescence intensity in cells was analyzed by the fluorescence microscope and ImageJ 1.49 software using a semi-quantitative method. The COL1A1 and EGFP mRNA were detected by reverse transcription real-time quantitative PCR (RT-qPCR), and corresponding proteins were detected by Western blot.@*RESULTS@#The recombinant plasmid pLVX-COL1A1-EGFP with the expression of EGFP regulated by COL1A1 promoter was successfully constructed. Kozak sequence was added to enhance the expression of EGFP, which was identified by double digestion and sequencing. The LX-2 monoclonal cell line LX-2-CE stably transfected with pLVX-COL1A1-EGFP was obtained. After co-treatment with TGF-β1 and 5 μmol/L dihydrotanshinone Ⅰ with potential anti-hepatic fibrosis effect for 24 h, the total fluorescence intensity and the average fluorescence intensity of LX-2-CE were lower than those in TGF-β1 single treatment group (P < 0.05), the intracellular mRNA and protein levels of COL1A1 and EGFP were also lower than those in the TGF-β1 single treatment group (P < 0.05).@*CONCLUSION@#A reporter system for estimating activation of hepatic stellate cells based on COL1A1 promoter regulated EGFP expression is successfully constructed, which could visually report the changes in COL1A1 expression, one of the activation-related markers of hepatic stellate cells, in vitro. It provides a new cell model for the screening and study of anti-hepatic fibrosis drugs.

Effect of plumbagin on levels of Nox4/ROS andα-SMA in human hepatic stellate cells / 中国病理生理杂志

AIM:To observe the effect of plumbagin on the mRNA and protein expression of nicotinamide ade -nine dinucleotidephosphate oxidase 4 ( Nox4 ) , reactive oxygen species ( ROS ) level and protein expression of α-smooth muscle actin (α-SMA) in the HSC-LX2 cells stimulated with transforming growth factor β1 (TGF-β1) in vitro.METH-ODS:HSC-LX2 cells were cultured in vitro and divided into blank group, model group, high-, medium-and low-dose (2, 1.5 and 1 μmol/L) plumbagin groups .After incubated with each drug for 72 h, the mRNA expression of Nox4 was detec-ted by RT-PCR.ROS levels were tested by in situ loading probe method.The protein contents of Nox4 and α-SMA were measured by Western blot .RESULTS:Compared with model group , after treated with plumbagin for 72 h, the mRNA ex-pression of Nox4, ROS level and α-SMA protein were significantly decreased in high-and medium-dose plumbagin groups (P<0.01).CONCLUSION:Plumbagin inhibits the activation of HSC-LX2 cells via decreasing the expression of Nox4, thus decreasing ROS levels .