Expression and correlation of angiotensin-converting enzyme 2 in CCl4-induced rat liver fibrosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the expression and pathogenic relevance of angiotensin-converting enzyme 2 (ACE2) in liver fibrosis by using the rat model of CCl4-induced liver fibrosis.</p><p><b>METHODS</b>The liver fibrosis model was generated by delivering subcutaneous injections of CCl4 (dissolved in olive oil at a 2:3 ratio; injection dose: 3 ml/kg) every three days for six weeks into male Sprague-Dawley rats. Another group of rats that received simultaneous injections of olive oil alone (3 ml/kg) were used as controls. At week 0, 2, 4, or 6 after the first injection, a subset of rats from each group was sacrificed to obtain liver tissues and serum samples. Pathological analyses were carried out to detect the presence and extent of liver cell degeneration, necrosis, inflammatory cell infiltration, and collagen deposition. ACE2 and ACE gene and protein expressions were measured by real-time PCR and Western blotting, respectively. The significance of differential expression between groups and time points was assessed by t-test and one-way ANOVA or Kruskal-Wallis tests, and correlation with fibrosis was assessed by Spearman's rank correlation coefficient.</p><p><b>RESULTS</b>CCl4 administration led to significantly up-regulated ACE2 mRNA levels at week 2 (3.055+/-1.034), 4 (3.545+/-1.947), and 6 (6.448+/-1.836) (vs. controls; H = 23.224, P less than 0.001). Similarly, hepatic ACE mRNA was significantly increased after the CCl4 injections (week 2: 3.055+/-1.034, week 4: 3.545+/-1.947, week 6: 6.448+/-1.836; vs. controls: F = 12.982, P less than 0.001). There was a significant correlation between the ACE and ACE2 gene expression levels (r = 0.750, P less than 0.001). Protein levels of ACE2 also showed an increasing trend following CCl4 administration (week 0: 0.034, week 2: 0.097, week 4: 0.356, week 6: 0.512). The hepatic ACE2 gene expression strongly correlated with levels of alanine aminotransferase (r = 0.669, P less than 0.0001) and aspartate aminotransferase (r = 0.815, P less than 0.0001), and with the Ishak fibrosis score (r = 0.850, P less than 0.001). Finally, there was a significant correlation between circulating ACE2 and the Ishak fibrosis score (r = 0.730, P less than 0.001).</p><p><b>CONCLUSION</b>A significant relationship exists between ACE2 gene expression and extent of liver fibrosis. ACE2 may play a crucial role in liver fibrogenesis.</p>

Real-time quantification of microRNAs in Huh7 cells by stem-loop reverse transcriptase polymerase chain reaction / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To establish a convenient realtime PCR which can detect microRNAs in the human hepatoma cell line, Huh7 cells.</p><p><b>METHODS</b>Total RNAs in Huh7 cells were extracted. MicroRNA 122, 24 and 146a were assayed by microRNA array, and then verified by Northern blot. Stem-loop RT-PCR and poly(A)-tailed RT-PCR were used to detect the above microRNAs. Data were analyzed with Quantity One software and 7500 system software.</p><p><b>RESULTS</b>Microarray signal intensity of microRNA 122, 24 and 146a in Huh7 cells was 2201.49, 410.20 and 4.70, whose relative expression was confirmed as 0.0383, 0.0249, 0.0001 through Northern blot. While the poly(A)-tailed RT-PCR might only measure microRNA 122, Stem-loop RT-PCR could detect microRNA 122, 24 and 146a, whose average dCt was 2.5, 5.8 and 12.1 in accordance with microRNA array and Northern blot.</p><p><b>CONCLUSION</b>Stem-loop RT-PCR can specifically and sensitively quantity microRNA levels, regardless of their abundance.</p>

The effect of N-acetyl-L-cysteine on endoplasmic reticulum stress mediated apoptosis of HepG2 cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To analyze the mechanisms of NAC on endoplasmic reticulum (ER) stress mediated cells apoptosis of HepG2 cells and to evaluate the potential role of NAC in the treatment of liver injury.</p><p><b>METHODS</b>HepG2 cells were treated with H2O2 to make a model of oxidative ER stress mediated apoptosis. To evaluate the apoptosis, various methods such as MTT, DNA ladder, Western blot and flow cytometry were used. Then the optimal dosage and incubation time of NAC intervention in apoptosis were ascertained, and the differences between induction and intervention of apoptosis, including the percentage of apoptosis, the expression of apoptotic protein (GRP78, Caspase-12, PARP) and the production of reactive oxygen species (ROS) were compared.</p><p><b>RESULTS</b>The activity of the cells decreased by H2O2 (0, 1, 3, 5 mmol/L) treatments in a dose-dependent manner. The ratio of apoptotic cells increased (0.7%+/-0.5%, 26.4%+/-1.8%, 29.7%+/-1.2% and 51.2%+/-9.4%, respectively) as did the production of ROS (14.0%+/-0.5%, 95.2%+/-0.1%, 97.5%+/-0.2% and 98.3%+/-0.2%, respectively). The HepG2 cells showed typical morphologic change of ER stress 6 hr after they were treated with 3 mmol/L H2O2. ER stress mediated-apoptosis was confirmed by Western blot. NAC (10 mmol/L and 20 mmol/L) protected cells from apoptosis. Typical features of ER stress apoptosis were seen accompanied by diminishing the ratio of apoptotic cells from 29.7%+/-1.2% to 23.3%+/-4.7% and 14.3%+/-1.2%. The production of ROS also decreased from 97.5%+/-0.2% to 52.2%+/-0.8% and 51.2%+/-2.9%. The effect was related to the concentration: 20 mmol/L NAC was more effective than 10 mmol/L.</p><p><b>CONCLUSIONS</b>As an oxidizing agent, H2O2 may induce ROS in cells and induce oxidative stress, causing ER stress and apoptosis. NAC can inhibit the procession of ROS directly and prevent injuries to the hepatocytes.</p>

Expression of Toll-like receptor 3 on peripheral blood dendritic cells in HBeAg positive patients with chronic hepatitis B / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To elucidate the roles of Toll-like receptor 3 (TLR3) on dendritic cells (DCs) in HBV infection.</p><p><b>METHODS</b>Peripheral blood mononuclear cells (PBMCs) were isolated from 48 healthy volunteers (HV) and 50 chronically HBV-infected patients (CH). DCs were induced and proliferated in a culture medium with rhGM-CSF and rhIL-4. We stimulated DCs with poly I:C and then TLR3, HLA-DR, and CD86, and CD1a expressions were examined by flow cytometry at 0 h, 12 h, 24 h and 48 h. The mRNA expressions of TLR3 were quantified by real-time PCR.</p><p><b>RESULTS</b>TLR3 expression on DCs before the poly I:C stimulation and afterwards on the 12 h, 24 h, and 48 h were 69.2%+/-20.4%, 76.0%+/-18.6%, 78.2%+/-19.5% and 85.5%+/-6.9% respectively in the CH group, and 70.8%+/-11.2%, 67.5%+/-20.9%, 86.3%+/-14.7%, 68.6%+/-16.9% in the HV group. The expressions of TLR3 were up-regulated significantly at 24 h and 48 h after stimulation with poly I:C in the HV group, and in the CH group they were not significantly increased at 24 h but obviously increased at 48 h. The mRNA expressions of TLR3 increased significantly at 12 h in the HV groups, and at 48 h in CH group. The rate of CD86 expressions increased after poly I:C stimulation, and the increased rates were 12.6%+/-9.8%, 23.8%+/-20.0%, 20.7%+/-14.3% in the CH group, and 31.0%+/-25.0%, 43.4%+/-24.7%, 44.6%+/-25.5% in the HV group at 12 h, 24 h and 48 h after poly I:C stimulation. There was a marked increase of the expression level of CD86 in the HV group. In contrast, the level was only slightly increased in the CH group (31.0% vs 12.6%). The differences between the two groups were significant at 24 h and 48 h. No significant differences were detected in HLA-DR and CD1a between the two groups.</p><p><b>CONCLUSIONS</b>The increase of expression level of TLR3 is slower in the CH group than that in the HV group. A marked increase of the expression level of CD86 is observed in the HV group. Our results suggest that abnormal expression of TLR3 and CD86 may relate to the persistence of HBV infection.</p>

Toll like receptor 9 expression and functions of plasmacytoid dendritic cells in the peripheral blood of patients with chronic hepatitis B virus infection / 中华传染病杂志

Objective To investigate the expression of Toll-like receptor(TLR) 9 of circulating plasmacytoid dendritic cell (pDC) and analyze the frequency and interferon (IFN)-?production of circulating pDC during hepatitis B virus(HBV) infection.Methods Peripheral blood was collected from 69 HBV-infected patients,including 14 cases of asymptomatie HBV infection,30 cases of chro- nic hepatitis B(CHB),25 cases of HBV-related liver cirrhosis,and 21 healthy blood donors as con- trols.Flow cytometry was used to analyze the frequency of circulating pDC and the mean fluorescence intensity(MFI) of TLR9.Fresh peripheral blood mononuclear cells(PBMC) were stimulated by CpG ODN 2216 for 24 h in vitro.IFN-?in the supernatant was measured using enzyme-linked immunosorbent assay(ELISA) to analyze the frequency and IFN-?production of pDC during HBV in- fection.Data were analyzed with SPSS 13.0 for windows.Results Compared with healthy controls (62.6?10.7),the MFI of TLR9 of patients with asymptomatic HBV infection,those of CHB and HBV-related cirrhosis were significantly reduced (P

Construction and identification of a specific small interfering RNA expression vector of Caspase-12 in mouse hepatoma cell line / 中华传染病杂志

Objective To construct a specific small interfering double-stranded RNA(siRNA) expression vector of Caspase-12 and to evaluate inhibitory effect of this siRNA on caspase-12 mRNA activity.Methods Three groups of siRNA targeting different gene sites of caspase-12 were designed and synthesized chemically.Mouse hepatoma cell line,Hepa1-6,was transfected with the siRNA by 24 h.Reverse transcription-polymerase chain reaction(RT-PCR)was performed to analyze the inhibi- tion of caspase-12.Then the most effective siRNA was selected and the two template sequences for the siRNA were inserted into pRNAT-H1.1Neo expression vector.The recombinant plasmid, referred to as pRNAT-casp12,was verified by PCR analysis and sequencing.The expression of caspase-12 at mRNA and protein level,after transfection with pRNAT-casp12 by 48 h and 72 h respectively,were analyzed by using real-time PCR and Western blotting.Results The chemically synthesized siRNA*1 and siRNA*3 could inhibit mouse hepatoma cell caspase-12 mRNA by 59.9% and 39.6%(P