AIM:To investigate the effects of the heme oxygenase(HO)-1/carbon monoxide system on iron deposition and portal pressure in rats with hepatic fibrosis induced by bile duct ligation(BDL).METHODS:Male Sprague-Dawley rats were divided randomly into a Sham group,BDL group,Fe group,deferoxamine(DFX) group,zinc protoporphyrin(ZnPP) group and cobalt protoporphyrin(CoPP) group.The levels of HO-1 were detected using different methods.The serum carboxyhemoglobin(COHb),iron,and portal vein pressure(PVP) were also quantified.The plasma and mRNA levels of hepcidin were measured.Hepatic fibrosis and its main pathway were assessed using Van Gieson’s stain,hydroxyproline,transforming growth factor-β1(TGF-β1),nuclear factor-E2-related factor 2(Nrf2),matrix metalloproteinase-2(MMP-2) and tissue inhibitor of metalloproteinase-1(TIMP-1).RESULTS:Serum COHb and protein and mRNA expression levels of HO-1 and Nrf2 were increased in the BDL group compared with the Sham group and were much higher in the CoPP group.The ZnPP group showed lower expression of HO-1 and Nrf2 and lower COHb.The levels of iron and PVP were enhanced in the BDL group but were lower in the ZnPP and DFX groups and were higher in the CoPP and Fe groups.Hepcidin levels were higher,whereas superoxide dismutase levels were increased and malonaldehyde levels were decreased in the ZnPP and DFX groups.The ZnPP group also showed inhibited TGF-β1 expression and regulated TIMP-1/MMP-2 expression,as well as obviously attenuated liver fibrosis.CONCLUSION:Reducing hepatic iron deposition and CO levels by inhibiting HO-1 activity though the Nrf2/Keap pathway could be helpful in improving hepatic fibrosis and regulating PVP.
AIM:To investigate the effect of zinc protoporphyrin IX on the response of hepatoma cells to cisplatin and the possible mechanism involved.METHODS:Cytotoxicity was determined using the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was determined by a flow cytometric assay.Western blotting was used to measure protein expression.Heme oxygenase(HO)-1 activity was measured by determining the level of bilirubin generated in isolated microsomes.Reactive oxygen species(ROS)production was monitored by flow cytometry.Caspase-3 activity was measured with a colorimetric assay kit.Mice were inoculated with 1×107 tumor cells subcutaneously into the right flanks.All mice were sacrificed 6 wk after the first treatment and tumors were weighed and measured.RESULTS:Overexpression of HO-1 in HepG2 cell line was associated with increased chemoresistance to cisdiaminedichloroplatinum(cisplatin;CDDP)compared to other cell lines in vitro.Inhibition of HO-1 expression or activity by zinc protoporphyrin IX(ZnPP IX)markedly augmented CDDP-mediated cytotoxicity towards all liver cancer cell lines in vitro and in vivo.In contrast,induction of HO-1 with hemin increased resistance of tumor cells to CDDP-mediated cytotoxicity in vitro and in vivo.Furthermore,cells treated with ZnPP IX plus CDDP exhibited marked production of intracellular ROS and caspase-3 activity,which paralleled the incidence of cell apoptosis,whereas hemin decreased cellular ROS and caspase-3 activity induced by CDDP.CONCLUSION:ZnPP IX increases cellular sensitivity and susceptibility of liver cancer cell lines to CDDP and this may represent a mechanism of increasing ROS.
AIM:To investigate the efficacy and molecularmechanisms of induced heme oxygenase(HO)-1 in protecting liver from warm ischemia/reperfusion(I/R)injury.METHODS:Partial warm ischemia was produced in the left and middle hepatic lobes of SD rats for 75min,followed by 6 h of reperfusion.Rats were treated with saline,cobalt protoporphyrin(Co PP)or zinc protoporphyrin(Zn PP)at 24 h prior to the ischemia insult.Blood and samples of ischemic lobes subjected to ischemia were collected at 6 h after reperfusion.Serum transaminases level,plasma lactate dehydrogenase and myeloperoxidase activity in liver were measured.Liver histological injury and inflammatory cell infiltration were evaluated by tissue section and liver immunohistochemical analysis.We used quantitative reverse transcription polymerase chain reaction to analyze liver expression of inflammatory cytokines and chemokines.The cell lysates were subjected to immunoprecipitation with anti-Toll-IL-1R-containing adaptor inducing interferon-β(TRIF)and anti-myeloid differentiation factor 88(My D88),and then the immunoprecipitates were analyzed by SDS-PAGE and immunoblotted with the indicated antibodies.RESULTS:HO-1 protected livers from I/R injury,as evidenced by diminished liver enzymes and wellpreserved tissue architecture.In comparison with Zn PP livers 6 h after surgery,Co PP treatment livers showed a significant increase inflammatory cell infiltration of lymphocytes,plasma cells,neutrophils and macrophages.The Toll-like receptor(TLR)-4 and TANK binding kinase1 protein levels of rats treated with Co PP significantly reduced in TRIF-immunoprecipitated complex,as compared with Zn PP treatment.In addition,pretreatment with Co PP reduced the expression levels of TLR2,TLR4,IL-1R-associated kinase(IRAK)-1 and tumor necrosis factor receptor-associated factor 6 in My D88-immunoprecipitated complex.The inflammatory cytokines and chemokines m RNA expression rapidly decreased inCo PP-pretreated liver,compared with the Zn PP-treat...
This study examined the ability of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (β-PGG) to induce the expression of heme oxygenase-1 (HO-1) in the PC12 cells and its regulation in the PC12 cells.One week before treatment with the drug,nerve growth factor (NGF) was added to the cultures at a final concentration of 50 ng/mL to induce neuronal differentiation.After drug treatment,HO-1 gene transcription was analyzed by reverse transcription polymerase chain reaction (RT-PCR).Expression of HO-1 and NF-E2-related factor2 (Nrf2) and activation of extracellular signal-regulated kinase (ERK) and Akt were detected by Western blotting.The viability of the PC12 cells treated with different medicines was examined by MTT assay.The oxidative stress in the PC12 cells was evaluated qualitatively and quantitatively by DCFH-DA.The results showed that β-PGG up-regulated HO-1 expression and this increased expression provided neuroprotection against MPP+-induced oxidative injury.Moreover,β-PGG induced Nrf2 nuclear translocation,which was found to be upstream of β-PGG-induced HO-1 expression,and the activation of ERK and Akt,a pathway that is involved in β-PGG-induced Nrf2 nuclear translocation,HO-1 expression and neuroprotection.In conclusion,β-PGG up-regulates HO-1 expression by stimulating Nrf2 nuclear translocation in an ERK-and Akt-dependent manner,and HO-1 expression by β-PGG may provide the PC12 cells with an acquired antioxidant defense capacity to survive the oxidative stress.
目的：探討蘭索拉唑對幽門螺桿菌（helicobacter pylori，Hp）感染的胃上皮細胞的體外抗炎效應。方法體外培養胃上皮細胞系AGS，加入蘭索拉唑和培養的Hp感染不同時間。ELISA檢測IL-1β和IL-8的產生，Western blot檢測NF-κB p 65亞基的核轉位以及紅素氧合?1（Heme oxygenase-1， HO-1）蛋白表達水平。結果蘭索拉唑孵育8 h后，能顯著抑制Hp誘導的IL-1β和IL-8。同時，蘭索拉唑能抑制NF-κB p 65亞基的核轉位，并能上調HO-1蛋白的表達。結論蘭索拉唑可能通過抑制NF-κB的激活，上調HO-1的表達而發揮對胃上皮細胞的抗炎作用。