Long-term lamivudine treatment achieves regression of advanced liver fibrosis/cirrhosis in patients with chronic hepatitis B.

BACKGROUND AND AIM: Antiviral therapy is important in advanced liver fibrosis/cirrhosis with chronic hepatitis B (AdLF-CHB) patients, but complete regression of cirrhosis remains to be the challenge. We aimed to investigate whether up to 10 years lamivudine treatment achieves liver fibrosis/cirrhosis regression in AdLF-CHB patients. METHODS: Improvement of hepatic fibrosis/cirrhosis, virological response and disease progression were evaluated in 28 AdLF-CHB patients with up to 10 years lamivudine treatment. Liver biopsy was performed in all of the 28 patients at baseline, but only 19 patients had second biopsy at year 10. RESULTS: There were 24 hepatitis B e antigen (HBeAg)-positive and 4 HBeAg-negative patients within the original 28 AdLF-CHB patients. At the end of 10 years lamivudine treatment, 20 of the 24 HBeAg-positive patients had HBeAg loss. HBeAg seroconversion was detected in 10 of these 20 HBeAg loss patients. HBsAg loss was observed in 4 of the original 28 patients. Among these four HBsAg loss patients, three had HBsAg seroconversion. All patients achieved hepatitis B virus DNA (HBV DNA) undetectable. Histopathology was evaluated between paired original and final liver biopsies among 19 patients as follows: 4/19 achieved complete liver fibrosis/cirrhosis regression; 9/19 improved in Ishak fibrosis score; whereas 6/19 showed no fibrosis improvement. About 75% patients achieved inflammatory/fibrotic improvement. No significant disease progression was observed in 24/28 patients. Furthermore, no significant difference in histopathology improvement, cirrhosis regression, disease progression between non-resistance and rescue for resistance was observed. CONCLUSION: Long-term lamivudine therapy achieves regression of fibrosis/cirrhosis and improvement of histological and disease progression in AdLF-CHB patients.

Telbivudine versus lamivudine in Chinese patients with chronic hepatitis B: Results at 1 year of a randomized, double-blind trial.

UNLABELLED: Chronic hepatitis B and its life-threatening sequelae are highly prevalent in China. There is a need for effective new therapies to suppress hepatitis B virus (HBV) replication and ameliorate liver disease. In this study, we compared the efficacy of telbivudine, a nucleoside analogue, with lamivudine in Chinese patients. In this phase III, double-blind, multicenter trial conducted in China, 332 patients with compensated hepatitis B e antigen (HBeAg)-positive or HBeAg-negative chronic hepatitis B were randomly assigned to treatment with 600 mg of telbivudine or 100 mg of lamivudine daily for 104 weeks. The primary efficacy endpoint was reduction in serum HBV DNA levels at week 52 of treatment. Secondary endpoints included clearance of HBV DNA to undetectable levels, HBeAg loss and seroconversion, therapeutic response, and alanine aminotransferase (ALT) normalization. Viral resistance and safety were assessed. At week 52, among 290 HBeAg-positive patients, mean reductions of serum HBV DNA were significantly greater in telbivudine recipients than lamivudine recipients (6.3 log(10) versus 5.5 log(10), P < 0.001), and HBV DNA was polymerase chain reaction-negative in significantly more telbivudine recipients than lamivudine recipients (67% versus 38%, P < 0.001). ALT normalization (87% versus 75%, P = 0.007), therapeutic response (85% versus 62%, P = 0.001), and HBeAg loss (31% versus 20%, P = 0.047) were also significantly more common in the telbivudine group. Treatment effects showed similar patterns in the smaller HBeAg-negative group (n = 42). Viral resistance in telbivudine recipients was approximately half that observed with lamivudine; however, this difference was not statistically significant. Clinical adverse events were similar in the two treatment groups. CONCLUSION: In Chinese patients with chronic hepatitis B, telbivudine treatment for 52 weeks provided greater antiviral and clinical efficacy than lamivudine, with less resistance.

[Results of 3 years of continuous entecavir treatment in nucleos(t)ide-naive chronic hepatitis B patients].

OBJECTIVE: To evaluate the virological, serological and biochemical outcomes of 3 years of entecavir (ETV) treatment in nucleoside-naive chronic hepatitis B patients. METHODS: This study was divided into two stages: Patients receiving either ETV 0.5 mg/d (n = 258) or lamivudine (LAM) 100 mg/d (n = 261) entered the initial 96-week randomized, double blind, controlled efficacy study. Patients not achieving a consolidated response (HBV DNA less than 0.7 MEq/ml, ALT less than 1.25 times*ULN, and if HBeAg-positive at baseline, loss of HBeAg for >or= 24 weeks), or those experienced viral breakthrough or relapse, entered a 48-week entecavir rollover study. RESULTS: 96 weeks after the treatment, 79% of ETV treated and 46% of LAM treated patients had HBV DNA less than 300 copies/ml (P < 0.0001), 96% of ETV treated and 92% of LAM treated patients had normalized ALT (P = 0.06). 21% of ETV treated and 23% of LAM treated patients achieved HBeAg seroconversion. Among the 160 patients received continuous ETV for 144 weeks, 89% had undetectable serum HBV DNA, 86% showed ALT normalization, and 27% achieved HBeAg seroconversion. ETV resistance was rare: only 3 patients showed ETV resistance 96 weeks after the treatment, and additional 2 patients developed ETV resistance during the following 48 weeks, genotyping indicated the ETV resistance was caused by gene mutation. Adverse event rates in ETV-treated patients were similar to those in LAM-treated patients, but fewer ALT flares were observed in ETV-treated patients. CONCLUSIONS: This study demonstrates that ETV treatment results in long-term HBV suppression and ALT normalization in Chinese CHB patients, and is associated with low rate of drug resistance.

Ribozyme-mediated inhibition of caspase-12 activity reduces apoptosis induced by endoplasmic reticulum stress in primary mouse hepatocytes.

Apoptosis via endoplasmic reticulum (ER) stress has been reported in many cell lines. ER stress plays an important role in many liver diseases and caspase-12 is the central player in ER stress-induced apoptosis. We conducted an investigation to determine whether catalytic cleavage of caspase-12 mRNA by hammerhead ribozymes can protect liver cells from apoptosis induced by ER stress. Thapsigargin (TG) was used to induce primary mouse hepatocytes apoptosis to establish the experimental system of ER stress- mediated apoptosis. The effective ribozyme-Rz138 selected in vitro was embedded in eukaryotic expression vector and transfected into cultured cells. The activity of Rz138 in primary mouse hepatocytes was determined by testing the expression of caspase-12 mRNA and procaspase-12 protein in ribozyme treated cells compared with the control. The anti-apoptotic effect was assayed by the nuclear morphological features of primary mouse hepatocytes stained with Hoechst 33258 under the fluorescence microscope. Primary mouse hepatocytes were incubated with 4 micromol/l TG, the percentage of apoptotic cells increased along with the treatment time, obvious apoptosis was observed after 4 micromol/l TG treatment for 30 h. Expression of caspase-12 mRNA and procaspase-12 protein were decreased significantly in hepatocytes transfected with pRz138 compared with those untransfected. The percentage of apoptotic cells was also decreased in pRz138 treated cells measured by staining with Hoechst 33258. Rz138, as a specific inhibitor of caspase-12 can down-regulate the expression of caspase-12 in primary mouse hepatocytes and protect the cells from apoptosis induced by TG. These results further elucidated the new treatment for diseases associated with ER stress-mediated apoptosis.

[Effects of CpG-ODN combined with HBsAg on the phenotype, function and the activity of NF-kappa B and AP-1 of monocyte-derived dendritic cells in chronic hepatitis B patients].

OBJECTIVE: To investigate the effect of synthetic non-methylated CpG-ODN combined with recombined HBsAg on the phenotype, function and the expression level of nucleic transcription factor NF-kappa B (NF-kB) and AP-1 of monocyte-derived dendritic cells (DC) in patients with chronic hepatitis B (CHB). METHODS: Purified monocytes were isolated from the peripheral blood of CHB patients and healthy volunteers and cultured with human granulocyte-monocyte colony stimulating factor added together with interleukin-4. On the fifth day of culture, CpG-ODN, HBsAg and other reagents, such as TNF alpha and PBS, were added to the medium, and 18 hours later cells were collected for the detection of surface molecules (HLA-DR/CD86/CD1a). IL-12p70 levels in the supernatant and stimulating capacity to allogenic T lymphocytes were detected. The nucleic proteins of NF-kB and AP-1 in DC were extracted and purified for the gel shift assay. RESULTS: Compared with those of the PBS group, the expression rates of HLA-DR of DC treated with CpG-ODN and/or HBsAg were obviously increased. Both the IL-12p70 level and the stimulating capacity of DC to allogenic T lymphocytes in mixed lymphocyte reaction increased significantly in the CpG-ODN group and in the CpG-ODN/HBsAg combination group (P less than 0.01 and 0.05, respectively). The expression rates of CD1a were raised only in the CpG-ODN/HBsAg combination group. Three kinds of immunological adjuvants, TNF alpha, CpG-ODN and CpG-ODN/HBsAg enhanced the expression of nucleic NF-kB and inhibited the expression of AP-1 in DC. CONCLUSION: CpG-ODN, like TNF alpha, has remarkable stimulatory effect on the impaired phenotype and function of monocyte-derived DC in patients with CHB; CpG-ODN and HBsAg have a synergetic effect in increasing the antigen presenting function. The regulating ability of CpG-ODN and TNF alpha on the expression levels of NF-kB and AP-1 might be one of the mechanisms of their immunostimulatory effects on DC of the CHB patients.

[The effect of N-acetyl-L-cysteine on endoplasmic reticulum stress mediated apoptosis of HepG2 cells].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Correlation between liver stem cell activation and histopathologic changes in liver with hepatic failure].

OBJECTIVE: To investigate the correlation between liver stem cell activation and histopathologic changes in liver transplant recipients with hepatic failure. METHODS: A total of 33 cases of hepatic failure were enrolled into the study. Donor liver tissues were used as normal controls. Histopathologic changes, presence of hepatotropic virus antigens, history of artificial liver therapy and number of c-kit positive cells were analyzed. RESULTS: There were a total of 25 males and 8 females. The age of patients ranged from 21 to 64 years. Among the 33 patients studied, 6 suffered from acute liver failure, 5 from subacute liver failure and the remaining from acute-on-chronic liver failure (associated with cirrhosis). Thirteen patients had a history of artificial liver therapy. Activated liver stem cells expressed c-kit monoclonal antibody but were negative for toluidine blue stain. The number of c-kit-positive cells in acute liver failure, subacute liver failure and acute-on-chronic liver failure were 3.50 +/- 2.66 (0 to 8) per mm(2), 11.47 +/- 8.85 (3 to 30) per mm(2) and 15.50 +/- 10.95 (5 to 45) per mm(2), respectively (P < 0.05). The number of c-kit-positive cells in cases with or without artificial liver therapy showed no statistically significant difference. CONCLUSIONS: The poor prognosis of acute liver failure is mainly due to massive liver necrosis and insufficient stem cell activation. Liver stem cell level is increased whenever there is progression into subacute liver failure and chronic liver failure. Actively treating acute liver failure with stimulation of the self-regeneration system in liver is thus useful.

[Histological changes in the livers of chronic hepatitis B patients with persistently normal serum alanine transaminase levels].

OBJECTIVE: To study the histological changes in livers of chronic hepatitis B (CHB) patients with persistently normal serum ALT levels (PNAL). METHODS: 274 CHB patients who had percutaneous liver biopsies and had a detectable viral load (lower limit of detection is 10(3) copies/ml) in our department between October 2003 and February 2007 were included in this study. Among these patients, 139 had PNAL, group A, (with at least 3 normal serum ALT levels, with intervals of more than two months over a period of 12 or more months before the biopsy). The other 135 patients, group B, had abnormal serum ALT levels during the same period. The histological changes in the livers of the two groups of patients were compared. RESULTS: Sixty-six (47.5%) patients with PNAL had normal liver histology, but significant pathohistological changes such as significant necroinflammation, fibrosis and/or cirrhosis were found in 33 (23.7%) patients. Thirteen (9.4%) had established cirrhosis. When compared to patients within (0-0.75)x upper limit of normal (ULN) ALT, patients within (0.76-1.00)x ULN ALT had higher scores of histological changes (43.5% vs. 19.8%, P < 0.05). In the PNAL group, scores of histological changes increased sharply in parallel with an age increase of older than 40 yrs. However neither viral loads nor HBeAg statuses of the PNAL patients had any predictive meaning to the scores of the histological findings. CONCLUSIONS: 23.7% of our CHB patients with PNAL, regardless of what their HBeAg statuses or viral load levels were, had significant liver pathohistological changes. Liver biopsies should be considered in CHB patients with PNAL, especially those older than 40 yrs and with a higher ALT within (0.76-1) x ULN.

[The degree of HBV suppression with 24 week telbivudine- or lamivudine-treatment in hepatitis B patients predicts the efficacy of the treatment at week 52].

OBJECTIVES: To investigate the possibilities of an association between the degrees of HBV suppression with nucleoside treatments at week 24 and week 52 in hepatitis B patients and to find a useful predictor for treatment efficacy. METHODS: In this phase III, double-blind, multicenter trial, we compared the efficacy of telbivudine treatment with lamivudine treatment in 332 Chinese compensated chronic hepatitis B patients. The patients were randomly assigned to a daily 600 mg telbivudine treatment group or daily 100 mg lamivudine group for 24 weeks. They were then categorized into 4 groups according to their serum HBV DNA levels (copies/ml) at week 24: a PCR-undetectable group (< 300 copies/ml); a QL- < 10(3) copies/ml group; a 10(3)-<10(4) copies/ml group; and a > or = 10(4) copies/ml group. The treatments were continued as they previously had been for another 28 weeks and the patients serum HBV DNA levels were examined again. RESULTS: At week 52, mean reductions of serum HBV DNA were significantly greater in the telbivudine-treated patients than in the lamivudine-treated group (6.2 log10 vs 5.4 log10, t = 3.6, P < 0.01). Viral resistance was twice as common in lamivudine-treated patients compared to those receiving telbivudine. Telbivudine was well-tolerated with an adverse event profile similar to that of lamivudine. The lower the HBV DNA level achieved at week 24, the higher HBV DNA non-detectable by PCR. ALT normalization and HBeAg seroconversion achieved at week 52, and viral resistance at week 48 decreased parallel to the degree of HBV DNA inhibition. CONCLUSION: HBV DNA PCR-undetectable at week 24 in nucleoside-treated hepatitis B patients suggests a better efficacy at week 52 and lower viral resistance at week 48. The degree of suppression of HBV at week 24 may be used as a predictor of 1-year outcome.

[Foscarnet sodium for treatment in patients with severe chronic hepatitis B].

OBJECTIVE: To investigate the effectiveness of foscarnet sodium in the treatment of severe chronic hepatitis B. METHODS: Two hundred and eight patients were enrolled in a multicenter, double-blind, controlled study. The patients received foscarnet sodium (foscarnet group) or saline (control group) injections for 4 weeks, and were then followed for 24 weeks. RESULTS: HBV DNA negative rate was 12.8% in the foscarnet group and 7.1% in the control group at the end of treatment; and it was 5.5% and 3.0% at the end of the follow-up period respectively (P > 0.05). The rate of HBV DNA decrease of more than 2 log copies/ml was 53.2% in the foscarnet group and 16.2% in the control group at the end of treatment, and 23.9% and 8.1% (P < 0.01) respectively at the end of the follow-up period. The rate of HBV DNA < 10(5) copies/ml was 64.2% and 30.3% at week 4 in the two groups respectively, and 40.4% and 22.2% (P < 0.01) at the end of the follow-up period. HBeAg negative rate was 17.3% and 5.8% at the end of the treatment, and 22% and 5.4% at the end of the follow-up period (P < 0.01). The rate of HBeAg seroconversion was 12.7% and 3.7% at week 4, and 16.7% and 1.5% at the end of the follow-up period. Response rate was 60.6% and 21.2% at the end of week 4 (P < 0.05). CONCLUSION: Foscarnet sodium injection has a good effect on severe chronic hepatitis B patients and it is safe to use on them.

Preparation of anti-mouse caspase-12 mRNA hammerhead ribozyme and identification of its activity in vitro.

AIM: To prepare and identify specific anti-mouse caspase-12 hammerhead ribozymes in vitro, in order to select a more effective ribozyme against mouse caspase-12 as a potential tool to rescue cells from endoplasmic reticulum stress induced apoptosis. METHODS: Two hammerhead ribozymes directed separately against 138 and 218 site of nucleotide of mouse caspase-12 mRNA were designed by computer software, and their DNA sequences were synthesized. The synthesized ribozymes were cloned into an eukaryotic expression vector-neo(r)pBSKU6 and embedded in U6 SnRNA context for further study. Mouse caspase-12 gene segment was cloned into PGEM-T vector under the control of T7 RNA polymerase promoter (containing gene sequence from positions nt 41 to nt 894) as target. In vitro transcription both the ribozymes and target utilize T7 promoter. The target was labeled with (alpha- (32)P)UTP, while ribozymes were not labeled. After gel purification the RNAs were dissolved in RNase free water. Ribozyme and target were incubated for 90 min at 37 degrees in reaction buffer (40 mmol/L Tris-HCL, pH 7.5, 10 mmol/L Mg(2+)). Molar ratio of ribozyme vs target was 30:1. Samples were analyzed on 6% PAGE(containing 8 mol/L urea). RESULTS: Both caspase-12 and ribozyme gene sequences were successfully cloned into expression vector confirmed by sequencing. Ribozymes and caspase-12 mRNA were obtained by in vitro transcription. Cleavage experiment showed that in a physiological similar condition (37 degrees, pH 7.5), Rz138 and Rz218 both cleaved targets at predicted sites, for Rz138 the cleavage efficiency was about 100%, for Rz218 the value was 36.66%. CONCLUSION: Rz138 prepared in vitro can site specific cleave mouse caspase-12 mRNA with an excellent efficiency. It shows a potential to suppress the expression of caspase-12 in vivo, thus provided a new way to protect cells from ER stress induced apoptosis.

Hybrid artificial liver support system for treatment of severe liver failure.

AIM: To construct a novel hybrid artificial liver support system (HALSS) and to evaluate its efficacy in patients with severe liver failure. METHODS: Hepatocytes were isolated from suckling pig by the modified Seglen's method. Isolated hepatocytes were cultured in a spinner flask for 24 h to form spheroids before use and the functions of spheroids were detected. HALSS consisted of a plasma separator, a hemo-adsorba and a bioreactor with hepatocytes spheroids in its extra-fiber space. HALSS was applied to 10 patients with severe liver failure. The general condition and the biochemical indexes of the patients were studied just before and after the treatment. RESULTS: The number of cells per liver was about 2-4 x 10(10) (mean, 3.1+/-1.5 x 10(10)). The cell viabilities were more than 95%. After 24 h of spheroid culture, most hepatocytes formed spheroids. The levels of albumin and urea in the medium of spheroid culture were higher than those in supernatant of petri dish culture (P = 0.0015 and 0.0001, respectively). The capacity of albumin production and urea synthesis remained stable for more than one wk and declined rapidly after two weeks in vitro. In HALSS group, the duration of HALSS treatment was 6-10 h each time. All patients tolerated the treatment well without any fatal adverse reaction. After HALSS treatment, the general condition, psychic state, encephalopathy and hepatic function of the patients were improved. The survival rate of the HALSS group, Plasmapheresis group and control group was 30% (3/10), 20% (2/10) and 0% (0/10), respectively (P = 0.024). Two weeks after treatment, Tbil and ALT decreased and the PTA level elevated in HALSS group and pasmapheresis group (P value: 0.015 vs 0.020, 0.009 vs 0.012 and 0.032 vs 0.041, respectively). But there was no significant change of blood albumin concentration before and after treatment in HALSS group and Plasmapheresis group. CONCLUSION: The HALSS established by us is effective in supporting liver function of patients with severe liver failure.

Multicenter clinical study on Fuzhenghuayu capsule against liver fibrosis due to chronic hepatitis B.

AIM: To study the efficacy and safety of Fuzhenghuayu capsule (FZHY capsule, a capsule for strengthening body resistance to remove blood stasis) against liver fibrosis due to chronic hepatitis B. METHODS: Multicenter, randomized, double blinded and parallel control experiment was conducted in patients (aged from 18 to 65 years) with liver fibrosis due to chronic hepatitis B. Hepatic histologic changes and HBV markers were examined at wk 0 and 24 during treatment. Serologic parameters (HA, LM, P-III-P, IV-C) were determined and B ultrasound examination of the spleen and liver was performed at wk 0, 12 and 24. Liver function (liver function and serologic parameters for liver fibrosis) was observed at wk 0, 6, 12, 18 and 24. Blood and urine routine test, renal function and ECG were examined before and after treatment. RESULTS: There was no significant difference between experimental group (110 cases) and control group (106 cases) in demographic features, vital signs, course of illness, history for drug anaphylaxis and previous therapy, liver function, serologic parameters for liver fibrosis, liver histologic examination (99 cases in experimental group, 96 cases in control group), HBV markers, and renal function. According to the criteria for liver fibrosis staging, mean score of fibrotic stage(s) in experimental group after treatment (1.80) decreased significantly compared to the previous treatment (2.33, P<0.05), but there was no significant difference in mean score of fibrotic stage(s) (2.11 and 2.14 respectively). There was a significant difference in reverse rate between experimental group (52%) and control group (23.3%) in liver biopsy. With marked effect on decreasing the mean value of inflammatory activity and score of inflammation (P<0.05), Fuzhenghuayu capsule had rather good effects on inhibiting inflammatory activity and was superior to that of Heluoshugan capsule. Compared to that of pretreatment, there was a significant decrease in HA, LM, P-III-P and IV-C content in experimental group after 12 and 24 wk of treatment. The difference in HA, LM, P-III-P and IV-C content between 12 and 24 wk of treatment and pretreatment in experimental group was significantly greater than that in control group (P<0.01-0.05). The effect, defined as two of four parameters lowering more than 30% of the baseline, was 72.7% in experimental group and 27.4% in control group (P<0.01). Obvious improvement in serum Alb, ALT, AST and GGT was seen in two groups. Compared to that of control group, marked improvement in GGT and Alb was seen in experimental group (P<0.05). The effective rate of improvement in serum ALT was 72.7% in experimental group and 59.4% in control group. No significant difference was seen in blood and urine routine and ECG before and after treatment. There was also no significant difference in stable rate in ALT and serologic parameters for liver fibrosis between experimental group and control group after 12 wk of withdrawal. CONCLUSION: Fuzhenghuayu capsule has good therapeutic effects on alleviating liver fibrosis due to chronic hepatitis B without any adverse effect and is superior to that of Heluoshugan capsule.

[Preparation and identification of hammerhead ribozyme in vitro against caspase-12 mRNA fragments].

OBJECTIVE: To design and synthesize ribozymes targeting 138 and 218 sites of the mRNA nucleotide of mouse caspase-12, a key intermedium of ER stress mediated apoptosis, and to identify their activities through in vitro transcription and cleavage. METHODS: The mouse caspase-12 gene fragment was obtained by RT-PCR and cloned into the PGEM-T vector under the control of T7 RNA polymerase promoter. The transcription product of the target was labeled with a-32P UTP, while ribozymes were not labeled. Ribozyme and target RNA were incubated for 90 min at 37 degree C in a reaction buffer to perform the cleavage reaction. RESULTS: It was found that under a condition of 37 degree C, pH 7.5 and with Mg2+ in a concentration of 10 mmol/L, Rz138 and Rz218 both cleaved targets at predicted sites, and the cleavage efficiency of Rz138 was 100%. CONCLUSION: Rz138 and Rz218 prepared in vitro possess the perfect specific catalytic cleavage activity. Rz138 has excellent cleavage efficiency. It may be a promising tool to prevent ER stress induced apoptosis through catalytic cleavage of caspase-12 mRNA in vivo. It also can be used to verify whether caspase-12 is necessary in ER stress induced apoptosis.

[Inhibition of mouse hepatocyte apoptosis by anti-caspase-12 small interfering RNA].

OBJECTIVES: To study the inhibition of primary mouse hepatocyte apoptosis by small interfering RNA (siRNAs) against caspase-12. METHODS: The Balb/c mouse primary hepatocytes were isolated in situ with two-step liver perfusion with 0.5 g/L collagenase type IV, and apoptosis were induced with 4 micromol/L thapsigargin (TG). The three kingds of siRNAs targeting different gene sites (130, 214, 521) were synthetized chemically. The single-stranded RNAs were annealed to produce double-stranded siRNAs, then the mouse primary hepatocytes were transfected by oligofectamine package. The inhibition of caspase-12 was analyzed with RT-PCR and Western-blot. The viable hepatocytes following the induction of apoptosis were evaluated with MTT. RESULTS: All the three kinds of siRNAs could obviously inhibit normal mouse hepatocyte caspase-12 mRNA. The siRNA (214) were more effective than the other two when the concentration was 100 nmol/L. The caspase-12 mRNA expression was inhibited by 52.08%, while that of siRNA (521) was 30.73% (t=4.30, P <0.05). However when the concentration was 200 nmol/L, the inhibitions were similar (88.07%, 86.22% and 89.41% respectively). siRNA (214) could downregulate the expression of apoptotic hepatocytes procaspase-12 by 51.43% ( t=4.30, P <0.01). Contrasted with apoptotic hepatocytes, the cell activity, which was analyzed with MTT, increased by 48.76% (t=2.23, P <0.01). CONCLUSION: siRNAs could effectively downregulate the expression of caspase-12 at mRNA and protein levels and prevent mouse primary hepatocytes from apoptosis.

[Caspase-12 expression and activation in the pathogenesis of acute hepatic failure induced by lipopolysaccharide and D-galactosamine].

OBJECTIVE: To study the role of caspase-12 expression on hepatocyte apoptosis in an experimental model of acute hepatic failure (AHF). METHODS: A mouse experimental model of AHF was developed by intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-Gal). Hepatocyte apoptosis was examined by DNA agarose gel and liver pathology. Caspase-12 mRNA expression in liver was detected by reverse transcriptase PCR (RT-PCR) method. The expression of caspase-12, GRP78 proteins in livers was determined by Western blot. RESULTS: Caspase-12 mRNA expression in the livers increased significantly from 5 to 7 hours after administration of LPS and D-Gal. Typical manifestation of hepatocyte apoptosis appeared at 5 hours after the drug administration. After 5 hours the level of serum ALT and AST were remarkably increased, and they reached the peak at 7 hours. The expression of procaspase-12 protein decreased obviously at 7 hours. Seven hours after the drug administration, hepatocyte apoptosis and necrosis both started. The marker of endoplasmic reticulum (ER) stress, Bip/GRP78 was activated during the development of hepatocyte apoptosis. The level of Bip/GRP78 protein was gradually increased at 5 hours after the drug induction. CONCLUSION: Hepatocyte apoptosis plays an important role in the pathogenesis of AHF. Caspase-12 induced ER stress involves in hepatocyte apoptosis. It suggests that inhibition of caspase-12 activation might be a potential strategy in the treatment of AHF in the future.

[A study of the dosage and efficacy of entecavir for treating hepatitis B virus].

OBJECTIVE: To evaluate the antiviral activity and safety of entecavir in patients with chronic HBV infection as a preliminarily step in selecting 0.1 mg or 0.5 mg as a better dosage for a further large scale clinical trial. METHODS: This was a randomized, double-blinded, placebo-controlled and dose-ranging trial of entecavir usage in 212 patients with chronic HBV infection. The patients were randomly assigned to 3 groups: 0.1 mg entecavir (69), 0.5 mg entecavir (72) and, placebo (71) groups and treated for 28 days. The patients were then followed for 56 days without treatment. RESULTS: The proportion of subjects who achieved the primary endpoint at day 28, with their HBV DNA level decreased >2 log or undetectable, was significantly greater in the entecavir 0.1 mg and 0.5 mg dose groups compared with the placebo group (P < 0.01 for both comparisons). The mean change from baseline in HBV DNA levels at day 28 was greater for entecavir 0.1mg and 0.5 mg groups compared with the placebo group (both P < 0.01). The mean change from baseline in HBV DNA levels at day 28 for entecavir 0.5 mg group was greater than that of the entecavir 0.1 mg group (P < 0.01). During the 56-day post-dosing follow-up phase, the entecavir 0.5 mg group was associated with greater and more sustained suppression of viral replication than the entecavir 0.1 mg group (P < 0.01). There were no clinically meaningful differences in the incidence of any adverse events between the entecavir dosing and the placebo groups. CONCLUSION: Entecavir at both 0.1 mg and 0.5 mg doses demonstrated superior antiviral activity compared with a placebo. Since the entecavir 0.5 mg dose appears to have greater antiviral activity than the 0.1 mg dose and with a comparable safety and tolerability profile, the 0.5 mg entecavir dose could be used in further trials.

[Clinical investigation of famciclovir in chronic hepatitis B patients irresponsive to alpha interferon treatment].

OBJECTIVES: To evaluate the efficacy and safety of famciclovir on the decreasing levels of serum HBV-DNA and ALT and HBeAg/antiHBe seroconversion in chronic hepatitis B patients irresponsive to 3 months treatment with alpha interferon. METHODS: Two hundred and nineteen patients with chronic HBV infection, defined as positive HBsAg, HBeAg and HBV DNA, were enrolled and randomly half-and- half put into famciclovir and placebo groups. The two groups received either famciclovir 500 mg tid or a placebo treatment for 24 weeks, and then were followed-up for another 24 weeks with no treatment. RESULTS: At the end of 24 weeks, the log value of HBV DNA dropped from 6.54+/-1.26 to 5.70+/-2.03 in the famciclovirt group and were elevated from 6.30+/-1.32 to 6.51+/-1.65 in the placebo group (P < 0.01). The rate of cases with persistence HBV DNA dropped 2 log of quantity in the famciclovir group and was 28.28% (28/99); it was 9.47% (9/95) in the placebo group (P < 0.01). Those with persistence negative HBV DNA was 28.28% (28/99) in the flamciclovir treated group and 14.74% (14/95) in the placebo group (P < 0.05). Those persistently being HBeAg negative were 7.69% (7/91) in the famciclovir treated group and 3.33% (3/90) in the placebo group (P > 0.05). The HBeAg/antiHBe seroconversion was 4.40% (4/91) in the famciclovir group and 2.22% (2/90) in the placebo group (P > 0.05). The percentage of cases with normal of ALT level was 15.15% in the famciclovir group and 6.35% in the placebo group (P < 0.05). CONCLUSION: Famciclovir is effective in inhibiting HBV DNA replication and in decreasing serum ALT levels. The rate of HBeAg/antiHBe seroconversion in the famciclovir treated group was similar to that of the placebo group. Famciclovir was well tolerated without severe adverse effects during our treatment.

Characterization and enrichment of hepatic progenitor cells in adult rat liver.

AIM: To detect the markers of oval cells in adult rat liver and to enrich them for further analysis of characterization in vitro. METHODS: Rat model for hepatic oval cell proliferation was established with 2-acetylaminofluorene and two third partial hepatectomy (2-AAF/PH). Paraffin embedded rat liver sections from model (11 d after hepatectomy) and control groups were stained with HE and OV6, cytokeratin19 (CK19), albumin, alpha fetoprotein (AFP), connexin43, and c-kit antibodies by immunohistochemistry. Oval cell proliferation was measured with BrdU incorporation test. C-kit positive oval cells were enriched by using magnetic activated cell sorting (MACS). The sorted oval cells were cultured in a low density to observe colony formation and to examine their characterization in vitro by immunocytochemistry and RT-PCR. RESULTS: A 2-AAF/PH model was successfully established to activate the oval cell compartment in rat liver. BrdU incorporation test of oval cell was positive. The hepatic oval cells coexpressed oval cell specific marker OV6, hepatocyte-marker albumin and cholangiocyte-marker CK19. They also expressed AFP and connexin 43. C-kit, one hematopoietic stem cell receptor, was expressed in hepatic oval cells at high levels. By using c-kit antibody in conjunction with MACS, we developed a rapid oval cell isolation protocol. The sorted cells formed colony when cultured in vitro. Cells in the colony expressed albumin or CK19 or coexpressed both and BrdU incorporation test was positive. RT-PCR on colony showed expression of albumin and CK19 gene. CONCLUSION: Hepatic oval cells in the 2-AAF/PH model had the properties of hepatic stem/progenitor cells. Using MACS, we established a method to isolate oval cells. The sorted hepatic oval cells can form colony in vitro which expresses different combinations of phenotypic markers and genes from both hepatocytes and cholangiocyte lineage.

Expression and in vitro cleavage activity of anti-caspase-7 hammerhead ribozymes.

AIM: To prepare hammerhead ribozymes against mouse caspase-7 and identify their cleavage activity in vitro, in order to select a ribozyme with specific cleavage activity against mouse caspase-7 as a potential gene therapy for apoptosis-related diseases. METHODS: Anti-caspase-7 ribozymes targeting sites 333 and 394 (named Rz333 and Rz394) were designed by computer software, and their DNA sequences encoding ribozymes were synthesized. Caspase-7 DNA sequence was acquired by RT-PCR. Ribozymes and caspase-7 DNA obtained by in vitro transcription were cloned into pBSKneo U6' and pGEM-T vectors, respectively. The cleavage activity of ribozymes against mouse caspase-7 was identified by cleavage experiments in vitro. RESULTS: Rz333 and Rz394 were designed and their DNA sequences were synthesized respectively. The expression vector of caspase-7 and plasmids containing Rz333 and Rz394 were reconstructed successfully. Ribozymes and caspase-7 mRNA were expressed by in vitro transcription. In vitro cleavage experiment showed that 243-nt and 744-nt segments were produced after caspase-7 mRNA was mixed with Rz333 in equivalent, and the cleavage efficiency was 67.98%. No cleaved segment was observed when caspase-7 mRNA was mixed with Rz394. CONCLUSION: Rz333 can site-specific cleave mouse caspase-7 mRNA, and it shows a potential for gene therapy of apoptosis-related diseases by down-regulating gene expression of caspase-7.