AIM:To investigate the influence of macrophages on hepatocyte phenotype and function.METHODS:Macrophages were differentiated from THP-1 monocytes via phorbol myristate acetate stimulation and the effects of monocyte o...AIM:To investigate the influence of macrophages on hepatocyte phenotype and function.METHODS:Macrophages were differentiated from THP-1 monocytes via phorbol myristate acetate stimulation and the effects of monocyte or macrophageconditioned medium on HepG2 mRNA and protein expression determined.The in vivo relevance of these findings was confirmed using liver biopsies from 147 patients with hepatitis C virus(HCV)infection.RESULTS:Conditioned media from macrophages,but not monocytes,induced a transient morphological change in hepatocytes associated with upregulation of vimentin(7.8±2.5-fold,P=0.045)and transforming growth factor(TGF)-β1(2.6±0.2-fold,P<0.001)and downregulation of epithelial cadherin(1.7±0.02-fold,P=0.017)mRNA expression.Microarray analysis revealed significant upregulation of lipocalin-2(17-fold,P <0.001)and pathways associated with inflammation,and substantial downregulation of pathways related to hepatocyte function.In patients with chronic HCV,realtime polymerase chain reaction and immunohistochemistry confirmed an increase in lipocalin-2 mRNA(F0 1.0 ±0.3,F1 2.2±0.2,F2 3.0±9.3,F3/4 4.0±0.8,P= 0.003)and protein expression(F1 1.0±0.5,F2 1.3± 0.4,F3/4 3.6±0.4,P=0.014)with increasing liver injury.High performance liquid chromatography-tandem mass spectrometry analysis identified elevated levels of matrix metalloproteinase(MMP)-9 in macrophageconditioned medium,and a chemical inhibitor of MMP-9 attenuated the change in morphology and mRNA expression of TGF-β1(2.9±0.2 vs 1.04±0.1,P<0.001) in macrophage-conditioned media treated HepG2 cells.In patients with chronic HCV infection,hepatic mRNA expression of CD163(F0 1.0±0.2,F1/2 2.8±0.3,F3/4 5.3±1.0,P=0.001)and MMP-9(F0 1.0±0.4,F1/2 2.8±0.3,F3/4 4.1±0.8,P=0.011)was significantly associated with increasing stage of fibrosis.CONCLUSION:Secreted macrophage products alter the phenotype and function of hepatocytes,with increased expression of inflammatory mediators,suggesting that hepatocytes actively participate in liver injury.展开更多
AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on wholebody and hepatic fat oxidation of patients with nonalcoholic fatty liver disease(NAFLD).METHODS Participant...AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on wholebody and hepatic fat oxidation of patients with nonalcoholic fatty liver disease(NAFLD).METHODS Participants were randomised into either circuit exercise training(EX;n = 13;3 h/wk without changes in dietary habits),or dietary energy restriction(ER) without changes in structured physical activity(ER;n = 8).Respiratory quotient(RQ) and whole-body fat oxidation rates(Fatox) were determined by indirect calorimetry under basal,insulin-stimulated and exercise conditions.Severity of disease and steatosis was determined by liver histology;hepatic Fatox was estimated from plasma β-hydroxybutyrate co.ncentrations;cardiorespiratory fitness was expressed as VO2 peak.Complete-case analysis was performed(EX:n = 10;ER:n = 6).RESULTS Hepatic steatosis and NAFLD activity score decreased with ER but not with EX.β-hydroxybutyrate concentrations increased significantly in response to ER(0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L,P = 0.03) but remained unchanged in response to EX(0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L,P = 0.39).Basal RQ decreased(P = 0.05) in response.to EX,while this change was not significant after ER(P = 0.38).VO_(2peak)(P < 0.001) and maximal Fa_(tox) during aerobic exercise(P = 0.03) improved with EX but not with ER(P > 0.05).The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis(r =-0.56,P = 0.04).CONCLUSION ER and EX lead to specific benefits on fat metabolism of patients with NAFLD.Increased hepatic Fat_(ox) in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.展开更多
基金Supported by The National Health and Medical Research Council of Australia,No.APP1003108the Queensland Government’s Smart State Health and Medical Research Fund+3 种基金The Princess Alexandra Hospital Research and Development FoundationThe Sasakawa Foundation(Royal Children’s Hospital,Brisbane)an Unrestricted Education Grant from MSD(to Powell EE)a Lions Medical Research Foundation Senior Research Fellowship(to Thomas GP)
文摘AIM:To investigate the influence of macrophages on hepatocyte phenotype and function.METHODS:Macrophages were differentiated from THP-1 monocytes via phorbol myristate acetate stimulation and the effects of monocyte or macrophageconditioned medium on HepG2 mRNA and protein expression determined.The in vivo relevance of these findings was confirmed using liver biopsies from 147 patients with hepatitis C virus(HCV)infection.RESULTS:Conditioned media from macrophages,but not monocytes,induced a transient morphological change in hepatocytes associated with upregulation of vimentin(7.8±2.5-fold,P=0.045)and transforming growth factor(TGF)-β1(2.6±0.2-fold,P<0.001)and downregulation of epithelial cadherin(1.7±0.02-fold,P=0.017)mRNA expression.Microarray analysis revealed significant upregulation of lipocalin-2(17-fold,P <0.001)and pathways associated with inflammation,and substantial downregulation of pathways related to hepatocyte function.In patients with chronic HCV,realtime polymerase chain reaction and immunohistochemistry confirmed an increase in lipocalin-2 mRNA(F0 1.0 ±0.3,F1 2.2±0.2,F2 3.0±9.3,F3/4 4.0±0.8,P= 0.003)and protein expression(F1 1.0±0.5,F2 1.3± 0.4,F3/4 3.6±0.4,P=0.014)with increasing liver injury.High performance liquid chromatography-tandem mass spectrometry analysis identified elevated levels of matrix metalloproteinase(MMP)-9 in macrophageconditioned medium,and a chemical inhibitor of MMP-9 attenuated the change in morphology and mRNA expression of TGF-β1(2.9±0.2 vs 1.04±0.1,P<0.001) in macrophage-conditioned media treated HepG2 cells.In patients with chronic HCV infection,hepatic mRNA expression of CD163(F0 1.0±0.2,F1/2 2.8±0.3,F3/4 5.3±1.0,P=0.001)and MMP-9(F0 1.0±0.4,F1/2 2.8±0.3,F3/4 4.1±0.8,P=0.011)was significantly associated with increasing stage of fibrosis.CONCLUSION:Secreted macrophage products alter the phenotype and function of hepatocytes,with increased expression of inflammatory mediators,suggesting that hepatocytes actively participate in liver injury.
基金Supported by the National Health and Medical Research Council of Australia(NHMRC),APP1044650 and APP1003108the Queensland Government’s Smart State Health and Medical Research Fund+5 种基金the Princess Alexandra Hospital Research and Development Foundation and The Australian Liver FoundationIrvine KM is the recipient of the Australian Liver Foundation Pauline Hall FellowshipPowell EE is the recipient of an NHMRC Practitioner Fellowship,APP1004242Sweet MJ is the recipient of an Australian Research Council(ARC)Future Fellowship,FT100100657an honorary NHMRC Senior Research Fellowship,APP1003470Hill MM is the recipient of an ARC Future Fellowship,FT120100251
文摘AIM: To develop a model of stress-induced senescence to study the hepatocyte senescence associated secretory phenotype (SASP).
基金Supported by The National Health and Medical Research Council of Australiathe Lions Medical Research Foundation
文摘AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on wholebody and hepatic fat oxidation of patients with nonalcoholic fatty liver disease(NAFLD).METHODS Participants were randomised into either circuit exercise training(EX;n = 13;3 h/wk without changes in dietary habits),or dietary energy restriction(ER) without changes in structured physical activity(ER;n = 8).Respiratory quotient(RQ) and whole-body fat oxidation rates(Fatox) were determined by indirect calorimetry under basal,insulin-stimulated and exercise conditions.Severity of disease and steatosis was determined by liver histology;hepatic Fatox was estimated from plasma β-hydroxybutyrate co.ncentrations;cardiorespiratory fitness was expressed as VO2 peak.Complete-case analysis was performed(EX:n = 10;ER:n = 6).RESULTS Hepatic steatosis and NAFLD activity score decreased with ER but not with EX.β-hydroxybutyrate concentrations increased significantly in response to ER(0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L,P = 0.03) but remained unchanged in response to EX(0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L,P = 0.39).Basal RQ decreased(P = 0.05) in response.to EX,while this change was not significant after ER(P = 0.38).VO_(2peak)(P < 0.001) and maximal Fa_(tox) during aerobic exercise(P = 0.03) improved with EX but not with ER(P > 0.05).The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis(r =-0.56,P = 0.04).CONCLUSION ER and EX lead to specific benefits on fat metabolism of patients with NAFLD.Increased hepatic Fat_(ox) in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.
