[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treat...[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy (APA); morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential (△ψm) intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential(△ψm) intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.展开更多
AIM: To analyze the clinical features and risk factors of adverse reactions associated with telbivudine. METHODS: Clinical data were collected from cases that presented with serious adverse reactions to telbivudine. W...AIM: To analyze the clinical features and risk factors of adverse reactions associated with telbivudine. METHODS: Clinical data were collected from cases that presented with serious adverse reactions to telbivudine. We analyzed general information and medicine status, clinical features, results of examination, and misdiagnosis. RESULTS: Out of 105 patients who were treated with telbivudine for hepatitis B in an outpatient department from January, 2007 to January, 2008, five presented with serious adverse drug reactions. Most of these five patients had used other nucleoside analogues in the past. Four were treated with a combination of telbivudine and interferon or another nucleoside analogue, while the other received an increased dose of telbivudine. The main adverse reactions were myalgia and general weakness. This was accompanied by cardiac arrhythmia in one patient, and nervous symptoms in three. Serum creatine kinase was elevated. The rate of misdiagnosis was high. CONCLUSION: The adverse reactions were related to telbivudine, but the biological mechanism of the reactions is not yet clear. Combination therapy with interferon or another nucleoside analogue and a high dose may increase the risk of adverse reactions.展开更多
AIM: To observe changes of mitochondria and investigate the effect of ethanol on mitochondrial perme- ability transition pore (PTP), mitochondrial membrane potential (MMP, ΔΨm) and intracellular calcium concentratio...AIM: To observe changes of mitochondria and investigate the effect of ethanol on mitochondrial perme- ability transition pore (PTP), mitochondrial membrane potential (MMP, ΔΨm) and intracellular calcium concentration in hepatocytes by establishing an animal model of alcoholic liver disease (ALD). METHODS: Fourty adult male Wistar rats were randomly divided into two groups, the model group (20) was administered alcohol intragastrically plus an Oliver oil diet to establish an ALD model, and the control group (20) was given an equal amount of normal saline. The ultramicrostructural changes of mitochondria were observed under electron microscopy. Mitochondria of liver was extracted, and patency of PTP, mitochondrial membrane potential (ΔΨm), mitochondrial mass and intracellular calcium concentration of isolated hepacytes were detected by flow cytometry using rhodamine123 (Rh123), Nonyl-Acridine Orange and calcium fluorescent probe Fluo-3/AM, respectively. RESULTS: Membrane and cristae were broken or disappeared in mitochondria in different shapes under electron microscopy. Some mitochondria showed U shape or megamitochondrion. In the model group, liver mitochondria PTP was broken, and mitochondria swelled, the absorbance at 450 nm, A540 decreased (0.0136 ± 0.0025 vs 0.0321 ± 0.0013, model vs control, P < 0.01); mitochondria transmembrane potential (239.4638 ± 12.7263 vs 377.5850 ± 16.8119, P < 0.01) was lowered; mitochondrial mass (17.4350 ± 1.9880 vs 31.6738 ± 3.4930, P < 0.01); and [Ca2+]i was increased in liver cells (7.0020 ± 0.5008 vs 10.2050 ± 0.4701, P < 0.01).CONCLUSION: Chronic alcohol intake might lead to broken mitochondria PTP, decreased mitochondria membrane potential and injury, and elevated intracellular Ca2+ production. Ethanol-induced chondriosome injury may be an important mechanism of alcoholic diseases.展开更多
Non-alcoholic fatty liver disease(NAFLD) is a common clinicopathological condition, encompassing a range of conditions caused by lipid deposition within liver cells. To date, no approved drugs are available for the tr...Non-alcoholic fatty liver disease(NAFLD) is a common clinicopathological condition, encompassing a range of conditions caused by lipid deposition within liver cells. To date, no approved drugs are available for the treatment of NAFLD, despite the fact that it represents a serious and growing clinical problem in the Western world. Identification of the molecular mechanisms leading to NAFLD-related fat accumulation, mitochondrial dysfunction and oxidative balance impairment facilitates the development of specific interventions aimed at preventing the progression of hepatic steatosis. In this review, we focus our attention on the role of dysfunctions in mitochondrial bioenergetics in the pathogenesis of fatty liver. Major data from the literature about the mitochondrial targeting of some antioxidant molecules as a potential treatment for hepatic steatosis are described and critically analysed. There is ample evidence of the positive effects of several classes of antioxidants, such as polyphenols(i.e., resveratrol, quercetin, coumestrol, anthocyanins, epigallocatechin gallate and curcumin), carotenoids(i.e., lycopene, astaxanthin and fucoxanthin) and glucosinolates(i.e., glucoraphanin, sulforaphane, sinigrin and allyl-isothiocyanate), on the reversion of fatty liver. Although the mechanism of action is not yet fully elucidated, in some cases an indirect interaction with mitochondrial metabolism is expected. We believe that such knowledge will eventually translate into the development of novel therapeutic approaches for fatty liver.展开更多
AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachlo...AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachloride (CCl4: 0.1 mL/10 g, ip), D-galactasamine (D-GaIN: 500 mg/kg, ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated. RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by the administration of CCl4, D-GaIN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dose dependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱ inhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism. CONCLUSION: Picroside II can evidently relieve hepatocyte injuries induced by CCI4, D-GaIN and AP, help scavenge free radicals, protect normal constructions of mitochondria membrane and enhance the activity of ATPase in mitochondria, thereby modulating the balance of liver energy metabolism, which might be part of the mechanisms of hepatoprotective effects of picroside Ⅱ.展开更多
Nonalcoholic fatty liver disease (NAFLD) includes hepatic steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. NAFLD is the most common liver disorder in the United States and worldwide. Due to the...Nonalcoholic fatty liver disease (NAFLD) includes hepatic steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. NAFLD is the most common liver disorder in the United States and worldwide. Due to the rapid rise of the metabolic syndrome, the prevalence of NAFLD has recently dramatically increased and will continue to increase. NAFLD has also the potential to progress to hepatocellular carcinoma (HCC) or liver failure. NAFLD is strongly linked to caloric overconsumption, physical inactivity, insulin resistance and genetic factors. Although significant progress in understanding the pathogenesis of NAFLD has been achieved in years, the primary metabolic abnormalities leading to lipid accumulation within hepatocytes has remained poorly understood. Mitochondria are critical metabolic organelles serving as "cellular power plants". Accumulating evidence indicate that hepatic mitochondrial dysfunction is crucial to the pathogenesis of NAFLD. This review is focused on the significant role of mitochondria in the development of NAFLD.展开更多
AIM:To survey glutathione(GSH) S-transferase(GST) isoforms in mitochondria and to reveal the isoforms' biological significance in diabetic mice.METHODS:The presence of GSTs in mouse liver mitochondria was systemat...AIM:To survey glutathione(GSH) S-transferase(GST) isoforms in mitochondria and to reveal the isoforms' biological significance in diabetic mice.METHODS:The presence of GSTs in mouse liver mitochondria was systematically screened by two proteomic approaches,namely,GSH affinity chromatography/two dimensional electrophoresis(2DE/MALDI TOF/TOF MS) and SDS-PAGE/LC ESI MS/MS.The proteomic results were further confirmed by Western blotting using monoclonal antibodies against GSTs.To evaluate the liver mitochondrial GSTs quantitatively,calibration curves were generated by the loading amounts of individual recombinant GST protein vs the relative intensities elicited from the Western blotting.An extensive comparison of the liver mitochondrial GSTs was conducted between normal and db/db diabetic mice.Student's t test was adopted for the estimation of regression and significant difference.RESULTS:Using GSH affinity/2DE/MALDI TOF/TOF MS,three GSTs,namely,alpha3,mu1 and pi1,were identified;whereas five GSTs,alpha3,mu1,pi1,kappa1 and zeta1,were detected in mouse liver mitochondria using SDS-PAGE/LC ESI MS/MS,of these GSTs,GST kappa1 was reported as a specific mitochondrial GST.The R 2 values of regression ranged between values of about 0.86 and 0.98,which were acceptable for the quantification.Based on the measurement of the GST abundances in liver mitochondria of normal and diabetic mice,the four GSTs,alpha3,kappa1,mu1 and zeta1,were found to be almost comparable between the two sets of animals,whereas,lower GST pi1 was detected in the diabetic mice compared with normal ones,the signal of Western blotting in control and db/db diabetic mice liver mitochondria is 134.61 ± 53.84 vs 99.74 ± 46.2,with P < 0.05.CONCLUSION:Our results indicate that GSTs exist widely in mitochondria and its abundances of mitochondrial GSTs might be tissue-dependent and disease-related.展开更多
Mitochondrial dysfunction is known to be a contributing factor to a number of diseases including chronic alcohol induced liver injury. While there is a detailed understanding of the metabolic pathways and proteins of ...Mitochondrial dysfunction is known to be a contributing factor to a number of diseases including chronic alcohol induced liver injury. While there is a detailed understanding of the metabolic pathways and proteins of the liver mitochondrion, little is known regarding how changes in the mitochondrial proteome may contribute to the development of hepatic pathologies. Emerging evidence indicates that reactive oxygen and nitrogen species disrupt mitochondrial function through post-translational modifications to the mitochondrial proteome. Indeed, various new affinity labeling reagents are available to test the hypothesis that post-translational modification of proteins by reactive species contributes to mitochondrial dysfunction and alcoholic fatty liver disease. Specialized proteomic techniques are also now available, which allow for identification of defects in the assembly of multi-protein complexes in mitochondria and the resolution of the highly hydrophobic proteins of the inner membrane. In this review knowledge gained from the study of changes to the mitochondrial proteome in alcoholic hepatotoxicity will be described and placed into a mechanistic framework to increase understanding of the role of mitochondrial dysfunction in liver disease.展开更多
lntracellular redox homeostasis plays a critical role in determining tumor cells' sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 (TRX1), a key component of redox regulation, i...lntracellular redox homeostasis plays a critical role in determining tumor cells' sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 (TRX1), a key component of redox regulation, in arsenic trioxide (AS2O3)-induced apoptosis. Over-expression of wild-type TRX1 in HepG2 cells led to the inhibition of As2O3-induced cytochrome c (cyto c) release, caspase activation and apoptosis, and down-regulation of TRX1 expression by RNAi sensitized HepG2 cells to As2O3-induced apoptosis. Interestingly, mutation of the active site of TRX1 from Cys^32/35 to Ser^32/35 converted this molecule from an apoptotic protector to an apoptotic promoter. In an effort to understand the mechanisms of this conversion, we used isolated mitochondria from mouse liver and found that recombinant wild-type TRX1 could protect mitochondria from the apoptotic changes. In contrast, the mutant form of TRX1 alone elicited mitochondria-related apoptotic changes, including the mitochondrial permeability transition pore (mPTP) opening, loss of mitochondrial membrane potential, and cyto c release from mitochondria. These apoptotic effects were inhibited by cyclosporine A (CsA), indicating that mutant TRX1 targeted to mPTP. Alteration of TRX1 from its reduced form to oxidized form in vivo by 2,4-dinitrochlorobenzene (DNCB), a specific inhibitor ofTRX reductase, also sensitized HepG2 cells to As203-induced apoptosis. These data suggest that TRX1 plays a central role in regulating apoptosis by blocking cyto c release, and inactivation of TRX1 by either mutation or oxidization of the active site cysteines may sensitize tumor cells to As2O3-induced apoptosis.展开更多
AIM: To examine how High-mobility group box I (HMGB1) regulates hepatocyte apoptosis and, furthermore, to determine whether glycyrrhizin (GL), a known HMGB1 inhibitor, prevents HMGBl-induced hepatocyte apoptosis.
Several studies have characterized the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic bile acids (BAs) in cholestatic diseases. BAs may disrupt cell membranes through t...Several studies have characterized the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic bile acids (BAs) in cholestatic diseases. BAs may disrupt cell membranes through their detergent action on lipid components and can promote the generation of reactive oxygen species that, in turn, oxidatively modify lipids, proteins, and nucleic acids, and eventually cause hepatocyte necrosis and apoptosis. Several pathways are involved in triggering hepatocyte apoptosis. Toxic BAs can activate hepatocyte death receptors directly and induce oxidative damage, thereby causing mitochondrial dysfunction, and induce endoplasmic reticulum stress. When these compounds are taken up and accumulate inside biliary cells, they can also cause apoptosis. Regarding extrahepatic tissues, the accumulation of BAs in the systemic circulation may contribute to endothelial injury in the kidney and lungs. In gastrointestinal cells, BAs may behave as cancer promoters through an indirect mechanism involving oxidative stress and DNA damage, as well as acting as selection agents for apoptosis-resistant cells. The accumulation of BAs may have also deleterious effects on placental and fetal cells. However, other BAs, such as ursodeoxycholic acid, have been shown to modulate BA-induced injury in hepatocytes. The major beneficial effects of treatment with ursodeoxycholic acid are protection against cytotoxicity due to more toxic BAs; the stimulation of hepatobiliary secretion; antioxidant activity, due in part to an enhancement in glutathione levels; and the inhibition of liver cell apoptosis. Other natural BAs or their derivatives, such as cholyI-N- methylglycine or pharmacological properties. cholylsarcosine, interest owing have also aroused to their protective展开更多
AIM: To clarify the mechanism underlying the anti-mutagenic and anti-cancer activities of Scorpio water extract (SWE). METHODS: Human hepatoma HepG2 cells were incubated with various concentrations of SWE. After 24-h ...AIM: To clarify the mechanism underlying the anti-mutagenic and anti-cancer activities of Scorpio water extract (SWE). METHODS: Human hepatoma HepG2 cells were incubated with various concentrations of SWE. After 24-h incubation, cytotoxicity and apoptosis evaluations were determined by MTT and DNA fragmentation assay, respectively. After treatment with SWE, mitochondrial membrane potential (MMP) was determined by measuring the retention of the dye 3,3'-dihexyloxacarbocyanine (DiOC6(3)) and the protein expression including cytochrome C and poly-(ADPribose) polymerase (PARP) were measured by Western blotting. Caspase-3 and -9 enzyme activities were measured using specific fluorescence dyes such as Ac-DEVD-AFC and Ac-LEHD-AFC. RESULTS: We found that treatment with SWE induced apoptosis as confirmed by discontinuous DNA fragmentation in cultured human hepatoma HepG2 cells. Our investigation also showed that SWE-induced apoptosis of HepG2 cells were associated with intracellular events including disruption of MMP, increased translocation of cytochrome C from mitochondria to cytosol, activation of caspase-3, and PARP. Pre-treatment of N-acetyl-Asp-Glu-Val-Asp-CHO (Ac-DEVD-CHO), a caspase-3 specific inhibitor, or cyclosporin A (CsA), an inhibitor of MMP disruption, completely abolished SWE-induced DNA fragmentation. CONCLUSION: These results suggest that SWE possibly causes mitochondrial damage, leading to cytochrome C release into cytosol and activation of caspases resulting in PARP cleavage and execution of apoptotic cell death in HepG2 cells. These results further suggest that Scorpio may be a valuable agent of therapeutic intervention of human hepatomas.展开更多
AIM: To determine whether alteration of the mito- chondria DNA (mtDNA) copy number and its oxidative damage index (mtDNA△CT) can be detected by analysis of peripheral blood cells in hepatitis C virus (HCV)- in...AIM: To determine whether alteration of the mito- chondria DNA (mtDNA) copy number and its oxidative damage index (mtDNA△CT) can be detected by analysis of peripheral blood cells in hepatitis C virus (HCV)- infected patients. METHODS: This study enrolled two groups of pa- tients aged 40-60 years: a control group and an HCV- infected group in Department of Gastroenterology and Hepatology in Changhua Christian Hospital. Patients with co-infection with hepatitis B virus or human im- munodeficiency virus, autoimmune disease, malignant neoplasia, pregnancy, thyroid disease, or alcohol con- sumption 〉 40 g/d were excluded. HCV-infected pa- tients who met the following criteria were included: (1) positive HCV antibodies for 〉 6 mo; (2) alanine aminotransferase (ALT) levels more than twice the upper lim- it of normal on at least two occasions during the past 6 mo; and (3) histological fibrosis stage higher than F1. The mtDNA copy number and oxidative damage index of HCV mtDNA (mtDNA△CT) were measured in periph- eral blood leukocytes. The association between mtDNA copy number and mtDNA△CT was further analyzed using clinical data. RESULTS: Forty-seven normal controls (male/female: 26/21, mean age 50.51 ± 6.15 years) and 132 HCV- infected patients (male/female: 76/61, mean age 51.65 ± 5.50 years) were included in the study. The geno- types of HCV-infected patients include type 1a (n = 3), type 1b (n = 83), type 2a (n = 32), and type 2b (n = 14). Liver fibrosis stages were distributed as follows: F1/F2/F3/F4 = 1/61/45/25 and activity scores were A0/ A1/A2/A3 = 7/45/55/25. There were no age or gender differences between the two groups. HCV-infected pa- tients had higher hepatitis activity (aspartate transami- nase levels 108.77 ± 60.73 vs 23.19 ± 5.47, P 〈 0.01; ALT levels 168.69 ± 93.12 vs 23.15 ± 9.45, P 〈 0.01) and lower platelet count (170.40±58.00 vs 251.24 ± 63.42, P 〈 0.01) than controls. The mtDNA copy num- ber was lower in HCV-infected patients than in controls (173.49 vs 247.93, P 〈 0.05). The mtDNA△CT was higher in HCV-infected patients than in controls (2.92 vs 0.64, P 〈 0.05). To clarify the clinical significance of these results in HCV-infected patients, their association with different clinical parameters among HCV-infected pa- tients was analyzed. A negative association was found between mtDNA copy number and elevated aspartate transaminase levels (r = -0.17, P 〈 0.05). Changes in mtDNA copy number were not associated with HCV RNA levels, HCV genotypes, liver fibrosis severity, or inflammatory activity in the liver biopsy specimen. How- ever, a correlation was observed between mtDNA△CT and platelet count (r = -0.22, P 〈 0.01), HCV RNA level (r = 0.36, P 〈 0.01), and hepatitis activity (r = 0.20, P = 0.02). However, no difference in the change in mtDNA△CT was observed between different fibrosis stages or HCV CONCLUSION: Oxidative stress and mtDNA dam- age are detectable in patient's peripheral leukocytes. Increased leukocyte mtDNA△CT correlates with higher HCV viremia, increased hepatitis activity, and lower platelet count.展开更多
AIM:To investigate the effects of tectorigenin on human hepatocellular carcinoma(HCC)HepG2 cells.METHODS:Tectorigenin,one of the main components of rhizome of Iris tectorum,was prepared by simple methods,such as extra...AIM:To investigate the effects of tectorigenin on human hepatocellular carcinoma(HCC)HepG2 cells.METHODS:Tectorigenin,one of the main components of rhizome of Iris tectorum,was prepared by simple methods,such as extraction,filtration,concentration,precipitation and recrystallization.HepG2 cells were incubated with tectorigenin at different concentrations,and their viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was detected by morphological observation of nuclear change,agarose gel electrophoresis of DNA ladder,and flow cytometry with Hoechst 33342,Annexin V-EGFP and propidium iodide staining.Generation of reactive oxygen species was quantified using DCFH-DA.Intracellular Ca2+was monitored by Fura 2-AM.Mitochondrial membrane potential was monitored using Rhodamine 123.Release of cytochrome c from mitochondria to cytosol was detected by Western blotting.Activities of caspase-3,-8 and-9 were investigated by Caspase Activity Assay Kit.RESULTS:The viability of HepG2 cells treated by tectorigenin decreased in a concentration-and timedependent manner.The concentration that reduced the number of viable HepG2 cells by 50%(IC50)after 12,24 and 48 h of incubation was 35.72 mg/L,21.19 mg/L and 11.06 mg/L,respectively.However,treatment with tectorigenin at 20 mg/L resulted in a very slight cytotoxicity to L02 cells after incubation for 12,24 or 48 h.Tectorigenin at a concentration of 20 mg/L greatly inhibited the viability of HepG2 cells and induced the condensation of chromatin and fragmentation of nuclei.Tectorigenin induced apoptosis of HepG2 cells in a time-and dose-dependent manner.Compared with the viability rate,induction of apoptosis was the main mechanism of the anti-proliferation effect of tectorigenin in HepG2 cells.Furthermore,tectorigenininduced apoptosis of HepG2 cells was associated with the generation of reactive oxygen species,increased intracellular[Ca2+]i,loss of mitochondrial membrane potential,translocation of cytochrome c,and activation of caspase-9 and-3.CONCLUSION:Tectorigenin induces apoptosis of HepG2 cells mainly via mitochondrial-mediated pathway,and produces a slight cytotoxicity to L02 cells.展开更多
OBJECTIVE: To study the clinical features of patients with primary biliary cirrhosis (PBC) in order to improve the doctors' awareness of the disease. METHODS: General status, clinical manifestations and laboratory...OBJECTIVE: To study the clinical features of patients with primary biliary cirrhosis (PBC) in order to improve the doctors' awareness of the disease. METHODS: General status, clinical manifestations and laboratory findings of 40 patients with PBC were reviewed.Thirty-seven patients were females (37/40), and the mean age at diagnosis was 50.5 +/- 7.8 years. The time interval from initial symptoms or preliminary diagnosis to final diagnosis was 24.0 +/- 23.6 months. RESULTS: The most frequently reported symptoms were fatigue (67.5%, 27/40), jaundice (60%, 24/40) and pruritus (32.5%, 17/40). Eight patients (20%) had associated auto-immune diseases (Sjogren's syndrome and/or rheumatoid a(c)arthritis). Serum alkaline phosphatase (ALP) and gamma glutamyl transpeptidase (gamma-GT) levels were markedly elevated (520.3 +/- 382.3 IU/L and 648.6 +/- 529.1 IU/L, respectively) in all patients, while alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were mildly elevated (82.6 +/- 54.5 IU/L and 100.7 +/- 47.2 IU/L, respectively). Twenty-four patients (60%) had a total bilirubin level >/= 34.2 micromol/L. Thirty-five patients (87.5%) had elevated serum immunoglobin M,and 97.5% of patients (39/40 ) were anti-mitochondrial antibody (AMA)/AMA-M2 positive. CONCLUSION: Elevated serum ALP and gamma-GT levels, together with a positive AMA/AMA-M2, can help the diagnosis of PBC. Liver biopsy is useful to confirm the diagnosis and to differentiate histopathological stages.展开更多
To examine whether metabolic compensation during seasonal acclimatization at the liver mitochondrial level is consistent with that at the whole-animal level, respiration rates of liver mitochondria and resting metabol...To examine whether metabolic compensation during seasonal acclimatization at the liver mitochondrial level is consistent with that at the whole-animal level, respiration rates of liver mitochondria and resting metabolic rates in winter- and sum- meracclimatized southern catfish (Silurus meridionalis Chen) were measured. At 12.5, 17.5, 22.5, 27.5 and 32.5~C, the mean values of state 3 respiration rates were 12.21, 13.84, 18.96, 24.78 and 32.01 nmol O2min-1 mg-1 mitochondrial protein in the winter group, and 8.56, 9.20, 17.32, 22.74 and 26.32 nmol 02 min-1 mgq in the summer group, respectively. At the five assay temperatures the resting metabolic rates were 24.86, 42.68, 61.59, 84.10 and 125.65 mg 02 h-1 kgI body mass in the winter group, and 22.89, 40.59, 52.94, 75.13 and 109.35 mg Oz h-1 kg-1 in the summer group, respectively. Total mitochondrial respiration rates in the liver organ were estimated based on state 3 respiration rates, mitochondrial protein content and organ mass, and the mean values were 72.96, 71.87, 112.47, 167.35 and 183.27 nmol Ozmin-lin the winter group, and were 47.89, 47.39, 105.67, 138.18 and 132.29 nmol 02 min-1 in the summer group, respectively. Metabolic compensation caused by seasonal acclimatization occurred at the liver mitochondrial level and compensation at the liver organ level was found to be more efficient because of an in- crease in metabolic capacity of mitochondria and a boost in organ mass. Metabolic compensation at the whole-animal level was not detected. During seasonal acclimatization, the effect of metabolic compensation at liver mitochondrial level is inconsistent with that at the whole-animal level in the southern catfish. This may be due to different degrees of regulation of metabolic mechanisms among various tissues and organs in an acclimatized organism展开更多
Analysis of the mitochondrial proteome would provide valuable insight into the function of this important organelle, which plays key roles in energy metabolism, apoptosis, free radical production, thermogenesis, and c...Analysis of the mitochondrial proteome would provide valuable insight into the function of this important organelle, which plays key roles in energy metabolism, apoptosis, free radical production, thermogenesis, and calcium signaling. It could also increase our understanding about the mechanisms that promote mitochondrial disease. To identify proteins that are antigenically dominant in human liver mitochondria, we generated >240 hybridoma cell lines from native mitochondrial proteins after cell fusion, screening, and cloning. Antibodies that recognized mitochondrial proteins were identified by screening human liver cDNA expression libraries. In this study, we identified 6 major antigens that were recognized by at least 2 different monoclonal antibodies (mAbs). The proteins that were antigenically dominant were: acetyl-Coenzyme A acyltransferase 2 (mitochondrial 3-oxoacyl-Coenzyme A thiolase), aldehyde dehydrogenase 1 family member A1, carbamoyl phosphate synthetase 1, dihydrolipoamide S-acetyltransferase (E2 component of pyruvate dehydrogenase complex), enoyl coenzyme A hydratase 1, and hydroxysteroid (11-beta) dehydrogenase 1. We also determined the subcellular localizations of these enzymes within the mitochondria using immunohistocytochemistry. We believe that these well-characterized antibodies will provide a valuable resource for the Human Liver Proteome Project (HLPP), and will make studies aimed at investigating liver mitochondrial function far easier to perform in future. Our results provide strong evidence that, (i) depletion of dominant proteins from liver mitochondrial samples is possible and, (ii) the approaches adopted in this study can be used to explore or validate protein-protein interactions in this important organelle.展开更多
Objective: To investigate the effects of seawater immersion on the function of myocardium and hepatocyte mitochondria in experimental hemorrhagic shock rats. Methods: Twenty-four male Wistar rats were divided into thr...Objective: To investigate the effects of seawater immersion on the function of myocardium and hepatocyte mitochondria in experimental hemorrhagic shock rats. Methods: Twenty-four male Wistar rats were divided into three groups (n=8 in each group): control group, HSL group (hemorrhagic shock group on land) and HSS group (hemorrhagic shock group in seawater). The hemodynamic parameters, activities of H+-ATPase (adenosinetriphosphatase), succinate dehydrogenase (SDH) and Ca 2+-Mg 2+-ATPase, the calcium contents in myocardium and hepatocyte mitochondria were measured and the changes of proton translocation across the inner mitochondrial membrane were analyzed. Results: The hemodynamic indexes and the activities of H+-ATPase, SDH, Ca 2+-Mg 2+-ATPase in HSS group were significantly lower than those in control group and HSL group (P< 0.05). In HSS group the calcium levels in tissue and mitochondria of myocardium and hepatocyte were elevated significantly compared with control group and HSL group(P< 0.05). There was no significant difference in proton translocation among three groups. Conclusions: This investigation demonstrates that seawater immersion can aggravate the conditions of hemorrhagic shock rats.展开更多
OBJECTIVE: To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus (C. orbiculatus) extract in human hepa- tocellular carcinoma cells. METHODS: Human hepatocellular carcin...OBJECTIVE: To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus (C. orbiculatus) extract in human hepa- tocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cells (HCCLM6) were treated with C. orbiculatus extract (COE) at different nontoxic concentrations (10, 20, 40, 80, and 160 IJg/mL). The effect of COE on HC-CLM6 viability was examined using 3-(4,5-dimethyl- thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Cellular apoptosis following COE treatment was assessed by flow cytometry and western blot analysis. RESULTS: COE significantly inhibited cell viability and induced apoptosis of HCCLM6 cells in a dose-dependent manner. Apoptosis was accompa- nied by increased Bax expression and decreased Bcl-2 expression. In addition, COE treatment led to the release of cytochrome c, activation of cas- pase-3, and cleavage of poly (ADP-ribose) poly- merase (PARP). Furthermore, activation of extracel- lular signal-regulated kinase (ERK), p38 kinase, and c-Jun N-terminal kinase (JNK) phosphorylation, and down-regulation of Akt phosphorylation was ob- served. CONCLUSION: COE induces mitochondrial-mediat- ed, caspase-dependent apoptosis in HCCLM6 cells, which might be attributed to the activation of mito- gen-activated protein kinase (MAPK) and inhibition of Akt signaling pathways. These data suggest that COE may be a potential treatment for human hepa- tocellular carcinoma.展开更多
基金Supported by the Natural Science Foundation of Shandong Province(ZR2011CM021)the Science and Technology Plan of Binzhou Medical University(BY2010KJ087)~~
文摘[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy (APA); morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential (△ψm) intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential(△ψm) intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.
文摘AIM: To analyze the clinical features and risk factors of adverse reactions associated with telbivudine. METHODS: Clinical data were collected from cases that presented with serious adverse reactions to telbivudine. We analyzed general information and medicine status, clinical features, results of examination, and misdiagnosis. RESULTS: Out of 105 patients who were treated with telbivudine for hepatitis B in an outpatient department from January, 2007 to January, 2008, five presented with serious adverse drug reactions. Most of these five patients had used other nucleoside analogues in the past. Four were treated with a combination of telbivudine and interferon or another nucleoside analogue, while the other received an increased dose of telbivudine. The main adverse reactions were myalgia and general weakness. This was accompanied by cardiac arrhythmia in one patient, and nervous symptoms in three. Serum creatine kinase was elevated. The rate of misdiagnosis was high. CONCLUSION: The adverse reactions were related to telbivudine, but the biological mechanism of the reactions is not yet clear. Combination therapy with interferon or another nucleoside analogue and a high dose may increase the risk of adverse reactions.
基金Supported by Natural Science Foundation of Shandong Province, No. 032050113
文摘AIM: To observe changes of mitochondria and investigate the effect of ethanol on mitochondrial perme- ability transition pore (PTP), mitochondrial membrane potential (MMP, ΔΨm) and intracellular calcium concentration in hepatocytes by establishing an animal model of alcoholic liver disease (ALD). METHODS: Fourty adult male Wistar rats were randomly divided into two groups, the model group (20) was administered alcohol intragastrically plus an Oliver oil diet to establish an ALD model, and the control group (20) was given an equal amount of normal saline. The ultramicrostructural changes of mitochondria were observed under electron microscopy. Mitochondria of liver was extracted, and patency of PTP, mitochondrial membrane potential (ΔΨm), mitochondrial mass and intracellular calcium concentration of isolated hepacytes were detected by flow cytometry using rhodamine123 (Rh123), Nonyl-Acridine Orange and calcium fluorescent probe Fluo-3/AM, respectively. RESULTS: Membrane and cristae were broken or disappeared in mitochondria in different shapes under electron microscopy. Some mitochondria showed U shape or megamitochondrion. In the model group, liver mitochondria PTP was broken, and mitochondria swelled, the absorbance at 450 nm, A540 decreased (0.0136 ± 0.0025 vs 0.0321 ± 0.0013, model vs control, P < 0.01); mitochondria transmembrane potential (239.4638 ± 12.7263 vs 377.5850 ± 16.8119, P < 0.01) was lowered; mitochondrial mass (17.4350 ± 1.9880 vs 31.6738 ± 3.4930, P < 0.01); and [Ca2+]i was increased in liver cells (7.0020 ± 0.5008 vs 10.2050 ± 0.4701, P < 0.01).CONCLUSION: Chronic alcohol intake might lead to broken mitochondria PTP, decreased mitochondria membrane potential and injury, and elevated intracellular Ca2+ production. Ethanol-induced chondriosome injury may be an important mechanism of alcoholic diseases.
文摘Non-alcoholic fatty liver disease(NAFLD) is a common clinicopathological condition, encompassing a range of conditions caused by lipid deposition within liver cells. To date, no approved drugs are available for the treatment of NAFLD, despite the fact that it represents a serious and growing clinical problem in the Western world. Identification of the molecular mechanisms leading to NAFLD-related fat accumulation, mitochondrial dysfunction and oxidative balance impairment facilitates the development of specific interventions aimed at preventing the progression of hepatic steatosis. In this review, we focus our attention on the role of dysfunctions in mitochondrial bioenergetics in the pathogenesis of fatty liver. Major data from the literature about the mitochondrial targeting of some antioxidant molecules as a potential treatment for hepatic steatosis are described and critically analysed. There is ample evidence of the positive effects of several classes of antioxidants, such as polyphenols(i.e., resveratrol, quercetin, coumestrol, anthocyanins, epigallocatechin gallate and curcumin), carotenoids(i.e., lycopene, astaxanthin and fucoxanthin) and glucosinolates(i.e., glucoraphanin, sulforaphane, sinigrin and allyl-isothiocyanate), on the reversion of fatty liver. Although the mechanism of action is not yet fully elucidated, in some cases an indirect interaction with mitochondrial metabolism is expected. We believe that such knowledge will eventually translate into the development of novel therapeutic approaches for fatty liver.
基金Supported by the China Postdoctoral Science Foundation and the National Natural Science Foundation of China, No. 90209046
文摘AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachloride (CCl4: 0.1 mL/10 g, ip), D-galactasamine (D-GaIN: 500 mg/kg, ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated. RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by the administration of CCl4, D-GaIN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dose dependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱ inhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism. CONCLUSION: Picroside II can evidently relieve hepatocyte injuries induced by CCI4, D-GaIN and AP, help scavenge free radicals, protect normal constructions of mitochondria membrane and enhance the activity of ATPase in mitochondria, thereby modulating the balance of liver energy metabolism, which might be part of the mechanisms of hepatoprotective effects of picroside Ⅱ.
文摘Nonalcoholic fatty liver disease (NAFLD) includes hepatic steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. NAFLD is the most common liver disorder in the United States and worldwide. Due to the rapid rise of the metabolic syndrome, the prevalence of NAFLD has recently dramatically increased and will continue to increase. NAFLD has also the potential to progress to hepatocellular carcinoma (HCC) or liver failure. NAFLD is strongly linked to caloric overconsumption, physical inactivity, insulin resistance and genetic factors. Although significant progress in understanding the pathogenesis of NAFLD has been achieved in years, the primary metabolic abnormalities leading to lipid accumulation within hepatocytes has remained poorly understood. Mitochondria are critical metabolic organelles serving as "cellular power plants". Accumulating evidence indicate that hepatic mitochondrial dysfunction is crucial to the pathogenesis of NAFLD. This review is focused on the significant role of mitochondria in the development of NAFLD.
基金Supported by The National Basic Research Program of China,No. 2010CB912703the Development Program of China,No.2006AA02A308the Nature Science Foundation of China,No. 30900508
文摘AIM:To survey glutathione(GSH) S-transferase(GST) isoforms in mitochondria and to reveal the isoforms' biological significance in diabetic mice.METHODS:The presence of GSTs in mouse liver mitochondria was systematically screened by two proteomic approaches,namely,GSH affinity chromatography/two dimensional electrophoresis(2DE/MALDI TOF/TOF MS) and SDS-PAGE/LC ESI MS/MS.The proteomic results were further confirmed by Western blotting using monoclonal antibodies against GSTs.To evaluate the liver mitochondrial GSTs quantitatively,calibration curves were generated by the loading amounts of individual recombinant GST protein vs the relative intensities elicited from the Western blotting.An extensive comparison of the liver mitochondrial GSTs was conducted between normal and db/db diabetic mice.Student's t test was adopted for the estimation of regression and significant difference.RESULTS:Using GSH affinity/2DE/MALDI TOF/TOF MS,three GSTs,namely,alpha3,mu1 and pi1,were identified;whereas five GSTs,alpha3,mu1,pi1,kappa1 and zeta1,were detected in mouse liver mitochondria using SDS-PAGE/LC ESI MS/MS,of these GSTs,GST kappa1 was reported as a specific mitochondrial GST.The R 2 values of regression ranged between values of about 0.86 and 0.98,which were acceptable for the quantification.Based on the measurement of the GST abundances in liver mitochondria of normal and diabetic mice,the four GSTs,alpha3,kappa1,mu1 and zeta1,were found to be almost comparable between the two sets of animals,whereas,lower GST pi1 was detected in the diabetic mice compared with normal ones,the signal of Western blotting in control and db/db diabetic mice liver mitochondria is 134.61 ± 53.84 vs 99.74 ± 46.2,with P < 0.05.CONCLUSION:Our results indicate that GSTs exist widely in mitochondria and its abundances of mitochondrial GSTs might be tissue-dependent and disease-related.
基金Supported by NIH/NIAAA grants AA13395 (VDU) and AA15172 (SMB)
文摘Mitochondrial dysfunction is known to be a contributing factor to a number of diseases including chronic alcohol induced liver injury. While there is a detailed understanding of the metabolic pathways and proteins of the liver mitochondrion, little is known regarding how changes in the mitochondrial proteome may contribute to the development of hepatic pathologies. Emerging evidence indicates that reactive oxygen and nitrogen species disrupt mitochondrial function through post-translational modifications to the mitochondrial proteome. Indeed, various new affinity labeling reagents are available to test the hypothesis that post-translational modification of proteins by reactive species contributes to mitochondrial dysfunction and alcoholic fatty liver disease. Specialized proteomic techniques are also now available, which allow for identification of defects in the assembly of multi-protein complexes in mitochondria and the resolution of the highly hydrophobic proteins of the inner membrane. In this review knowledge gained from the study of changes to the mitochondrial proteome in alcoholic hepatotoxicity will be described and placed into a mechanistic framework to increase understanding of the role of mitochondrial dysfunction in liver disease.
文摘lntracellular redox homeostasis plays a critical role in determining tumor cells' sensitivity to drug-induced apoptosis. Here we investigated the role of thioredoxin-1 (TRX1), a key component of redox regulation, in arsenic trioxide (AS2O3)-induced apoptosis. Over-expression of wild-type TRX1 in HepG2 cells led to the inhibition of As2O3-induced cytochrome c (cyto c) release, caspase activation and apoptosis, and down-regulation of TRX1 expression by RNAi sensitized HepG2 cells to As2O3-induced apoptosis. Interestingly, mutation of the active site of TRX1 from Cys^32/35 to Ser^32/35 converted this molecule from an apoptotic protector to an apoptotic promoter. In an effort to understand the mechanisms of this conversion, we used isolated mitochondria from mouse liver and found that recombinant wild-type TRX1 could protect mitochondria from the apoptotic changes. In contrast, the mutant form of TRX1 alone elicited mitochondria-related apoptotic changes, including the mitochondrial permeability transition pore (mPTP) opening, loss of mitochondrial membrane potential, and cyto c release from mitochondria. These apoptotic effects were inhibited by cyclosporine A (CsA), indicating that mutant TRX1 targeted to mPTP. Alteration of TRX1 from its reduced form to oxidized form in vivo by 2,4-dinitrochlorobenzene (DNCB), a specific inhibitor ofTRX reductase, also sensitized HepG2 cells to As203-induced apoptosis. These data suggest that TRX1 plays a central role in regulating apoptosis by blocking cyto c release, and inactivation of TRX1 by either mutation or oxidization of the active site cysteines may sensitize tumor cells to As2O3-induced apoptosis.
基金Supported by Samsung Biomedical Research Institute grant,No.SBRI C-A8-219-1
文摘AIM: To examine how High-mobility group box I (HMGB1) regulates hepatocyte apoptosis and, furthermore, to determine whether glycyrrhizin (GL), a known HMGB1 inhibitor, prevents HMGBl-induced hepatocyte apoptosis.
基金Supported by Instituto de Salud CarlosTM,FIS, Spain (GrantsPI070517 and PI080151)Fundacion Investigacion Medica Mutua Madrilea, Spain (Conv-TM,, 2006)+3 种基金Junta de Castillay Leon, Spain (Grants GR75-2008, SA033A08, SA03508 and SA03608)Ministerio de Ciencia y Tecnologia, Plan Nacional de Investigacion Cientifi ca, Desarrollo e Innovacion Tecnologica, Spain (Grant BFU2006-12577)The group is member of the Network for Cooperative Research on Membrane Transport Proteins (REIT), co-funded by the Ministerio de Educacion y Ciencia, Spain, and the European Regional Development Fund (ERDF) (Grant BFU2007-30688-E/BFI)belongs to the CIBERehd (Centro de Investigacion Biomedica en Red para el Estudio de Enfermedades Hepaticas y Digestivas), Instituto de Salud CarlosTM
文摘Several studies have characterized the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic bile acids (BAs) in cholestatic diseases. BAs may disrupt cell membranes through their detergent action on lipid components and can promote the generation of reactive oxygen species that, in turn, oxidatively modify lipids, proteins, and nucleic acids, and eventually cause hepatocyte necrosis and apoptosis. Several pathways are involved in triggering hepatocyte apoptosis. Toxic BAs can activate hepatocyte death receptors directly and induce oxidative damage, thereby causing mitochondrial dysfunction, and induce endoplasmic reticulum stress. When these compounds are taken up and accumulate inside biliary cells, they can also cause apoptosis. Regarding extrahepatic tissues, the accumulation of BAs in the systemic circulation may contribute to endothelial injury in the kidney and lungs. In gastrointestinal cells, BAs may behave as cancer promoters through an indirect mechanism involving oxidative stress and DNA damage, as well as acting as selection agents for apoptosis-resistant cells. The accumulation of BAs may have also deleterious effects on placental and fetal cells. However, other BAs, such as ursodeoxycholic acid, have been shown to modulate BA-induced injury in hepatocytes. The major beneficial effects of treatment with ursodeoxycholic acid are protection against cytotoxicity due to more toxic BAs; the stimulation of hepatobiliary secretion; antioxidant activity, due in part to an enhancement in glutathione levels; and the inhibition of liver cell apoptosis. Other natural BAs or their derivatives, such as cholyI-N- methylglycine or pharmacological properties. cholylsarcosine, interest owing have also aroused to their protective
文摘AIM: To clarify the mechanism underlying the anti-mutagenic and anti-cancer activities of Scorpio water extract (SWE). METHODS: Human hepatoma HepG2 cells were incubated with various concentrations of SWE. After 24-h incubation, cytotoxicity and apoptosis evaluations were determined by MTT and DNA fragmentation assay, respectively. After treatment with SWE, mitochondrial membrane potential (MMP) was determined by measuring the retention of the dye 3,3'-dihexyloxacarbocyanine (DiOC6(3)) and the protein expression including cytochrome C and poly-(ADPribose) polymerase (PARP) were measured by Western blotting. Caspase-3 and -9 enzyme activities were measured using specific fluorescence dyes such as Ac-DEVD-AFC and Ac-LEHD-AFC. RESULTS: We found that treatment with SWE induced apoptosis as confirmed by discontinuous DNA fragmentation in cultured human hepatoma HepG2 cells. Our investigation also showed that SWE-induced apoptosis of HepG2 cells were associated with intracellular events including disruption of MMP, increased translocation of cytochrome C from mitochondria to cytosol, activation of caspase-3, and PARP. Pre-treatment of N-acetyl-Asp-Glu-Val-Asp-CHO (Ac-DEVD-CHO), a caspase-3 specific inhibitor, or cyclosporin A (CsA), an inhibitor of MMP disruption, completely abolished SWE-induced DNA fragmentation. CONCLUSION: These results suggest that SWE possibly causes mitochondrial damage, leading to cytochrome C release into cytosol and activation of caspases resulting in PARP cleavage and execution of apoptotic cell death in HepG2 cells. These results further suggest that Scorpio may be a valuable agent of therapeutic intervention of human hepatomas.
基金Supported by Changhua Christian Hospital,99-CCH-IPR-12
文摘AIM: To determine whether alteration of the mito- chondria DNA (mtDNA) copy number and its oxidative damage index (mtDNA△CT) can be detected by analysis of peripheral blood cells in hepatitis C virus (HCV)- infected patients. METHODS: This study enrolled two groups of pa- tients aged 40-60 years: a control group and an HCV- infected group in Department of Gastroenterology and Hepatology in Changhua Christian Hospital. Patients with co-infection with hepatitis B virus or human im- munodeficiency virus, autoimmune disease, malignant neoplasia, pregnancy, thyroid disease, or alcohol con- sumption 〉 40 g/d were excluded. HCV-infected pa- tients who met the following criteria were included: (1) positive HCV antibodies for 〉 6 mo; (2) alanine aminotransferase (ALT) levels more than twice the upper lim- it of normal on at least two occasions during the past 6 mo; and (3) histological fibrosis stage higher than F1. The mtDNA copy number and oxidative damage index of HCV mtDNA (mtDNA△CT) were measured in periph- eral blood leukocytes. The association between mtDNA copy number and mtDNA△CT was further analyzed using clinical data. RESULTS: Forty-seven normal controls (male/female: 26/21, mean age 50.51 ± 6.15 years) and 132 HCV- infected patients (male/female: 76/61, mean age 51.65 ± 5.50 years) were included in the study. The geno- types of HCV-infected patients include type 1a (n = 3), type 1b (n = 83), type 2a (n = 32), and type 2b (n = 14). Liver fibrosis stages were distributed as follows: F1/F2/F3/F4 = 1/61/45/25 and activity scores were A0/ A1/A2/A3 = 7/45/55/25. There were no age or gender differences between the two groups. HCV-infected pa- tients had higher hepatitis activity (aspartate transami- nase levels 108.77 ± 60.73 vs 23.19 ± 5.47, P 〈 0.01; ALT levels 168.69 ± 93.12 vs 23.15 ± 9.45, P 〈 0.01) and lower platelet count (170.40±58.00 vs 251.24 ± 63.42, P 〈 0.01) than controls. The mtDNA copy num- ber was lower in HCV-infected patients than in controls (173.49 vs 247.93, P 〈 0.05). The mtDNA△CT was higher in HCV-infected patients than in controls (2.92 vs 0.64, P 〈 0.05). To clarify the clinical significance of these results in HCV-infected patients, their association with different clinical parameters among HCV-infected pa- tients was analyzed. A negative association was found between mtDNA copy number and elevated aspartate transaminase levels (r = -0.17, P 〈 0.05). Changes in mtDNA copy number were not associated with HCV RNA levels, HCV genotypes, liver fibrosis severity, or inflammatory activity in the liver biopsy specimen. How- ever, a correlation was observed between mtDNA△CT and platelet count (r = -0.22, P 〈 0.01), HCV RNA level (r = 0.36, P 〈 0.01), and hepatitis activity (r = 0.20, P = 0.02). However, no difference in the change in mtDNA△CT was observed between different fibrosis stages or HCV CONCLUSION: Oxidative stress and mtDNA dam- age are detectable in patient's peripheral leukocytes. Increased leukocyte mtDNA△CT correlates with higher HCV viremia, increased hepatitis activity, and lower platelet count.
基金Supported by The National Natural Science Foundation of China,No.NSFC30801417Natural Science Foundation of Jiangsu Province,No.BK2009010 and BK2008267+1 种基金Doctoral Fund of Ministry of Education of China,No.RFDP200802841004Science Fund of Ministry of Health of China,No.LW201008
文摘AIM:To investigate the effects of tectorigenin on human hepatocellular carcinoma(HCC)HepG2 cells.METHODS:Tectorigenin,one of the main components of rhizome of Iris tectorum,was prepared by simple methods,such as extraction,filtration,concentration,precipitation and recrystallization.HepG2 cells were incubated with tectorigenin at different concentrations,and their viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was detected by morphological observation of nuclear change,agarose gel electrophoresis of DNA ladder,and flow cytometry with Hoechst 33342,Annexin V-EGFP and propidium iodide staining.Generation of reactive oxygen species was quantified using DCFH-DA.Intracellular Ca2+was monitored by Fura 2-AM.Mitochondrial membrane potential was monitored using Rhodamine 123.Release of cytochrome c from mitochondria to cytosol was detected by Western blotting.Activities of caspase-3,-8 and-9 were investigated by Caspase Activity Assay Kit.RESULTS:The viability of HepG2 cells treated by tectorigenin decreased in a concentration-and timedependent manner.The concentration that reduced the number of viable HepG2 cells by 50%(IC50)after 12,24 and 48 h of incubation was 35.72 mg/L,21.19 mg/L and 11.06 mg/L,respectively.However,treatment with tectorigenin at 20 mg/L resulted in a very slight cytotoxicity to L02 cells after incubation for 12,24 or 48 h.Tectorigenin at a concentration of 20 mg/L greatly inhibited the viability of HepG2 cells and induced the condensation of chromatin and fragmentation of nuclei.Tectorigenin induced apoptosis of HepG2 cells in a time-and dose-dependent manner.Compared with the viability rate,induction of apoptosis was the main mechanism of the anti-proliferation effect of tectorigenin in HepG2 cells.Furthermore,tectorigenininduced apoptosis of HepG2 cells was associated with the generation of reactive oxygen species,increased intracellular[Ca2+]i,loss of mitochondrial membrane potential,translocation of cytochrome c,and activation of caspase-9 and-3.CONCLUSION:Tectorigenin induces apoptosis of HepG2 cells mainly via mitochondrial-mediated pathway,and produces a slight cytotoxicity to L02 cells.
文摘OBJECTIVE: To study the clinical features of patients with primary biliary cirrhosis (PBC) in order to improve the doctors' awareness of the disease. METHODS: General status, clinical manifestations and laboratory findings of 40 patients with PBC were reviewed.Thirty-seven patients were females (37/40), and the mean age at diagnosis was 50.5 +/- 7.8 years. The time interval from initial symptoms or preliminary diagnosis to final diagnosis was 24.0 +/- 23.6 months. RESULTS: The most frequently reported symptoms were fatigue (67.5%, 27/40), jaundice (60%, 24/40) and pruritus (32.5%, 17/40). Eight patients (20%) had associated auto-immune diseases (Sjogren's syndrome and/or rheumatoid a(c)arthritis). Serum alkaline phosphatase (ALP) and gamma glutamyl transpeptidase (gamma-GT) levels were markedly elevated (520.3 +/- 382.3 IU/L and 648.6 +/- 529.1 IU/L, respectively) in all patients, while alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were mildly elevated (82.6 +/- 54.5 IU/L and 100.7 +/- 47.2 IU/L, respectively). Twenty-four patients (60%) had a total bilirubin level >/= 34.2 micromol/L. Thirty-five patients (87.5%) had elevated serum immunoglobin M,and 97.5% of patients (39/40 ) were anti-mitochondrial antibody (AMA)/AMA-M2 positive. CONCLUSION: Elevated serum ALP and gamma-GT levels, together with a positive AMA/AMA-M2, can help the diagnosis of PBC. Liver biopsy is useful to confirm the diagnosis and to differentiate histopathological stages.
基金Acknowledgements This study was supported by the National Natural Science Foundation of China (30371121), Natural Science Foundation of Chongqing Government (2007BA7029), and Doctoral Foundation of Southwest University, China. We are grateful to LQ Yuan, Y Kong, DF Ming and B Wu for assistance with experiments. We also thank SL Miao for comments on an earlier version of this manuscript.
文摘To examine whether metabolic compensation during seasonal acclimatization at the liver mitochondrial level is consistent with that at the whole-animal level, respiration rates of liver mitochondria and resting metabolic rates in winter- and sum- meracclimatized southern catfish (Silurus meridionalis Chen) were measured. At 12.5, 17.5, 22.5, 27.5 and 32.5~C, the mean values of state 3 respiration rates were 12.21, 13.84, 18.96, 24.78 and 32.01 nmol O2min-1 mg-1 mitochondrial protein in the winter group, and 8.56, 9.20, 17.32, 22.74 and 26.32 nmol 02 min-1 mgq in the summer group, respectively. At the five assay temperatures the resting metabolic rates were 24.86, 42.68, 61.59, 84.10 and 125.65 mg 02 h-1 kgI body mass in the winter group, and 22.89, 40.59, 52.94, 75.13 and 109.35 mg Oz h-1 kg-1 in the summer group, respectively. Total mitochondrial respiration rates in the liver organ were estimated based on state 3 respiration rates, mitochondrial protein content and organ mass, and the mean values were 72.96, 71.87, 112.47, 167.35 and 183.27 nmol Ozmin-lin the winter group, and were 47.89, 47.39, 105.67, 138.18 and 132.29 nmol 02 min-1 in the summer group, respectively. Metabolic compensation caused by seasonal acclimatization occurred at the liver mitochondrial level and compensation at the liver organ level was found to be more efficient because of an in- crease in metabolic capacity of mitochondria and a boost in organ mass. Metabolic compensation at the whole-animal level was not detected. During seasonal acclimatization, the effect of metabolic compensation at liver mitochondrial level is inconsistent with that at the whole-animal level in the southern catfish. This may be due to different degrees of regulation of metabolic mechanisms among various tissues and organs in an acclimatized organism
基金supported by the National Basic Research Program of China (Grant No. 2006CB910803)the National High Technology Research and Development Program of China (Grant No. 2006AA02A311)
文摘Analysis of the mitochondrial proteome would provide valuable insight into the function of this important organelle, which plays key roles in energy metabolism, apoptosis, free radical production, thermogenesis, and calcium signaling. It could also increase our understanding about the mechanisms that promote mitochondrial disease. To identify proteins that are antigenically dominant in human liver mitochondria, we generated >240 hybridoma cell lines from native mitochondrial proteins after cell fusion, screening, and cloning. Antibodies that recognized mitochondrial proteins were identified by screening human liver cDNA expression libraries. In this study, we identified 6 major antigens that were recognized by at least 2 different monoclonal antibodies (mAbs). The proteins that were antigenically dominant were: acetyl-Coenzyme A acyltransferase 2 (mitochondrial 3-oxoacyl-Coenzyme A thiolase), aldehyde dehydrogenase 1 family member A1, carbamoyl phosphate synthetase 1, dihydrolipoamide S-acetyltransferase (E2 component of pyruvate dehydrogenase complex), enoyl coenzyme A hydratase 1, and hydroxysteroid (11-beta) dehydrogenase 1. We also determined the subcellular localizations of these enzymes within the mitochondria using immunohistocytochemistry. We believe that these well-characterized antibodies will provide a valuable resource for the Human Liver Proteome Project (HLPP), and will make studies aimed at investigating liver mitochondrial function far easier to perform in future. Our results provide strong evidence that, (i) depletion of dominant proteins from liver mitochondrial samples is possible and, (ii) the approaches adopted in this study can be used to explore or validate protein-protein interactions in this important organelle.
文摘Objective: To investigate the effects of seawater immersion on the function of myocardium and hepatocyte mitochondria in experimental hemorrhagic shock rats. Methods: Twenty-four male Wistar rats were divided into three groups (n=8 in each group): control group, HSL group (hemorrhagic shock group on land) and HSS group (hemorrhagic shock group in seawater). The hemodynamic parameters, activities of H+-ATPase (adenosinetriphosphatase), succinate dehydrogenase (SDH) and Ca 2+-Mg 2+-ATPase, the calcium contents in myocardium and hepatocyte mitochondria were measured and the changes of proton translocation across the inner mitochondrial membrane were analyzed. Results: The hemodynamic indexes and the activities of H+-ATPase, SDH, Ca 2+-Mg 2+-ATPase in HSS group were significantly lower than those in control group and HSL group (P< 0.05). In HSS group the calcium levels in tissue and mitochondria of myocardium and hepatocyte were elevated significantly compared with control group and HSL group(P< 0.05). There was no significant difference in proton translocation among three groups. Conclusions: This investigation demonstrates that seawater immersion can aggravate the conditions of hemorrhagic shock rats.
基金Supported by the National Natural Science Foundation of China(No.81173603 and No.81274141)State Administration of Traditional Chinese Medicine of China(No.0405ZP35)+3 种基金Jiangsu Provincial Social Development Project(No. BE2011738)the Natural Science Foundation of Jiangsu Province(No.BK2012686)Administration of Traditional Chinese Medicine of Jiangsu Province(No.LZ11210)and the Project of Cooperation between Yangzhou University and Yangzhou City(No.YZ2010157)
文摘OBJECTIVE: To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus (C. orbiculatus) extract in human hepa- tocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cells (HCCLM6) were treated with C. orbiculatus extract (COE) at different nontoxic concentrations (10, 20, 40, 80, and 160 IJg/mL). The effect of COE on HC-CLM6 viability was examined using 3-(4,5-dimethyl- thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Cellular apoptosis following COE treatment was assessed by flow cytometry and western blot analysis. RESULTS: COE significantly inhibited cell viability and induced apoptosis of HCCLM6 cells in a dose-dependent manner. Apoptosis was accompa- nied by increased Bax expression and decreased Bcl-2 expression. In addition, COE treatment led to the release of cytochrome c, activation of cas- pase-3, and cleavage of poly (ADP-ribose) poly- merase (PARP). Furthermore, activation of extracel- lular signal-regulated kinase (ERK), p38 kinase, and c-Jun N-terminal kinase (JNK) phosphorylation, and down-regulation of Akt phosphorylation was ob- served. CONCLUSION: COE induces mitochondrial-mediat- ed, caspase-dependent apoptosis in HCCLM6 cells, which might be attributed to the activation of mito- gen-activated protein kinase (MAPK) and inhibition of Akt signaling pathways. These data suggest that COE may be a potential treatment for human hepa- tocellular carcinoma.