Chronic Ethanol Exposure Potentiates Lipopolysaccharide Liver Injury Despite Inhibiting Jun N-terminal Kinase and Caspase 3 Activation

Abstract

Although ethanol is known to sensitize hepatocytes to tumor necrosis factor (TNF) lethality, the mechanisms involved remain controversial. Recently, others have shown that adding TNFα to cultures of ethanol-pretreated hepatocytes provokes the mitochondrial permeability transition, cytochrome crelease, procaspase 3 activation, and apoptosis. Although this demonstrates that ethanol can sensitize hepatocytes to TNF-mediated apoptosis, the hepatic inflammation and ballooning hepatocyte degeneration that typify alcohol-induced liver injury suggest that other mechanisms might predominate in vivo. To evaluate this possibility, acute responses to lipopolysaccharide (LPS), a potent inducer of TNFα, were compared in mice that had been fed either an ethanol-containing or control diet for 5 weeks. Despite enhanced induction of cytokines such as interleukin (IL)-10, IL-15, and IL-6 that protect hepatocytes from apoptosis, ethanol-fed mice exhibited a 4–5-fold increase in serum alanine aminotransferase after LPS, confirming increased liver injury. Six h post-LPS histology also differed notably in the two groups, with control livers demonstrating only scattered apoptotic hepatocytes, whereas ethanol-exposed livers had large foci of ballooned hepatocytes, inflammation, and scattered hemorrhage. No caspase 3 activity was noted during the initial 6 h after LPS in ethanol-fed mice, but this tripled by 1.5 h after LPS in controls. Procaspase 8 cleavage and activity of the apoptosis-associated kinase, Jun N-terminal kinase, were also greater in controls. In contrast, ethanol exposure did not inhibit activation of cytoprotective mitogen-activated protein kinases and AKT or attenuate induction of the anti-apoptotic factors NF-κB and inducible nitric oxide synthase. Consistent with these responses, neither cytochrome c release, an early apoptotic response, nor hepatic oligonucleosomal DNA fragmentation, the ultimate consequence of apoptosis, was increased by ethanol. Thus, ethanol exacerbates TNF-related hepatotoxicity in vivo without enhancing caspase 3-dependent apoptosis. Although ethanol is known to sensitize hepatocytes to tumor necrosis factor (TNF) lethality, the mechanisms involved remain controversial. Recently, others have shown that adding TNFα to cultures of ethanol-pretreated hepatocytes provokes the mitochondrial permeability transition, cytochrome crelease, procaspase 3 activation, and apoptosis. Although this demonstrates that ethanol can sensitize hepatocytes to TNF-mediated apoptosis, the hepatic inflammation and ballooning hepatocyte degeneration that typify alcohol-induced liver injury suggest that other mechanisms might predominate in vivo. To evaluate this possibility, acute responses to lipopolysaccharide (LPS), a potent inducer of TNFα, were compared in mice that had been fed either an ethanol-containing or control diet for 5 weeks. Despite enhanced induction of cytokines such as interleukin (IL)-10, IL-15, and IL-6 that protect hepatocytes from apoptosis, ethanol-fed mice exhibited a 4–5-fold increase in serum alanine aminotransferase after LPS, confirming increased liver injury. Six h post-LPS histology also differed notably in the two groups, with control livers demonstrating only scattered apoptotic hepatocytes, whereas ethanol-exposed livers had large foci of ballooned hepatocytes, inflammation, and scattered hemorrhage. No caspase 3 activity was noted during the initial 6 h after LPS in ethanol-fed mice, but this tripled by 1.5 h after LPS in controls. Procaspase 8 cleavage and activity of the apoptosis-associated kinase, Jun N-terminal kinase, were also greater in controls. In contrast, ethanol exposure did not inhibit activation of cytoprotective mitogen-activated protein kinases and AKT or attenuate induction of the anti-apoptotic factors NF-κB and inducible nitric oxide synthase. Consistent with these responses, neither cytochrome c release, an early apoptotic response, nor hepatic oligonucleosomal DNA fragmentation, the ultimate consequence of apoptosis, was increased by ethanol. Thus, ethanol exacerbates TNF-related hepatotoxicity in vivo without enhancing caspase 3-dependent apoptosis. tumor necrosis factor lipopolysaccharide TNF receptor pair-fed Jun N-terminal kinase electrophoretic mobility shift assay interleukin inducible nitric oxide synthase heat shock protein-70 mitogen-activated protein kinase extracellular signal-regulated kinase protein kinase B inhibitor κβ kinase Although ethyl alcohol has been recognized as a significant hepatotoxin for centuries, the mechanisms involved in alcohol-induced liver disease remain uncertain. It is known that chronic alcohol ingestion potentiates liver injury inflicted by many other toxins (1.Seeff L.B. Cuccherini B.A. Zimmerman H.J. Alder E. Benjamin S.B. Ann. Intern. Med. 1986; 104: 399-404Crossref PubMed Scopus (369) Google Scholar), viral hepatitis (2.Marsano L.S. Pena L.R. Hepatogastroenterology. 1998; 45: 331-339PubMed Google Scholar, 3.Serfaty L. Chazouilleres O. Poujol-Robert A. Morand-Joubert L. Dubois C. Chretien Y. Poupon R.E. Petit J.C. Poupon R. Hepatology. 1997; 26: 776-779Crossref PubMed Scopus (116) Google Scholar), and hepatic hypoxia-reoxygenation (4.Thurman R.G. Ji S. Matsumura T. Lemasters J.J. Fundam. Appl. Toxicol. 1984; 4: 125-133Crossref PubMed Google Scholar, 5.Israel Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Scholar) or ischemia-reperfusion (6.Gao W. Connor H.D. Lemasters J.J. Mason R.P. Thurman R.G. Transplantation. 1995; 59: 674-679Crossref PubMed Scopus (60) Google Scholar) and yet fails to cause serious liver damage in most healthy adults (7.Lelbach W.K. Prog. Liver Dis. 1976; 5: 494-513PubMed Google Scholar, 8.Pequignot G. Tuyns A.S. Berta J.L. Int. J. Epidemiol. 1978; 7: 113-120Crossref PubMed Scopus (191) Google Scholar, 9.Johnson R.D. Williams R. Alcohol Alcohol. 1985; 20: 137-142PubMed Google Scholar). These clinical observations suggest that ethanol exposure enhances hepatic vulnerability to a secondary inflammatory or oxidative stress, such that serious liver injury is most likely to occur when proinflammatory/pro-oxidant factors are superimposed onto a background of ethanol use (10.Day C.P. James O. Gastroenterology. 1998; 114: 842-845Abstract Full Text Full Text PDF PubMed Scopus (3406) Google Scholar). Because tumor necrosis factor-α ((TNFα)1 and cytokines that potentiate TNF activity are the common, proximal mediators of inflammatory liver injury (11.Vassalli P. Annu. Rev. Immunol. 1992; 10: 411-452Crossref PubMed Scopus (1798) Google Scholar, 12.Tracey K.J. Cerami A. Annu. Rev. Cell Biol. 1993; 9: 317-343Crossref PubMed Scopus (760) Google Scholar, 13.Baker S.J. Reddy E.P. Oncogene. 1996; 12: 1-9PubMed Google Scholar), several laboratories have been evaluating the possibility that ethanol may sensitize hepatocytes to TNF-related toxicity (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar, G. R. Alcohol. 1996; 20: PubMed Scopus Google Scholar, J.C. C. A. E. A. J. 1997; PubMed Google Scholar, H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar, Hepatology. PubMed Scopus Google Scholar). this is that ethanol enhances liver injury by lipopolysaccharide (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar), a that TNFα J. Toxicol. 1997; PubMed Scopus Google Scholar). of the that the TNF receptor mice from the liver injury that from chronic of ethanol H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar). demonstrates that TNFα is for liver disease in that mechanisms in is to the mechanisms that to TNF hepatocytes are to TNFα toxicity have been with that inhibit protein such TNFα the mitochondrial permeability transition, cytochrome c release, caspase 3 activation, and by G. A. J. Immunol. Google Scholar). Recently, and Hepatology. PubMed Scopus Google Scholar) that ethanol these of protein when or hepatocytes that have been with ethanol are to TNFα in mitochondrial permeability transition, cytochrome c release, caspase 3 activation, and Because of these cultures with mitochondrial permeability from TNF lethality, these Hepatology. PubMed Scopus Google Scholar) that ethanol the liver to injury by of the is to mechanisms in vivo. To ethanol and pair-fed mice were a of LPS, and liver damage as as activation of mechanisms that and inhibit were ethanol exposure enhanced liver injury these caspase 3 the increased liver damage in the ethanol-fed was not with increased cytochrome c or oligonucleosomal DNA these a the in mechanisms for ethanol hepatotoxicity and that to sensitize ethanol-exposed livers to TNF toxicity in vivo. In of TNF-mediated liver injury not caspase 3 activation, and hepatocyte to from from of have in that are to and in the vulnerability to alcohol-induced liver several of suggest that serious liver damage the of an inflammatory or to ethanol-exposed livers that have of factors that protect hepatocyte H. J. Med. PubMed Scopus Google Scholar). Thus, in the and cytoprotective factors the of liver damage in laboratories have this to and that can to for from many TNFα as a of liver damage (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar, G. R. Alcohol. 1996; 20: PubMed Scopus Google Scholar, J.C. C. A. E. A. J. 1997; PubMed Google Scholar, H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar, Hepatology. PubMed Scopus Google Scholar). Recent of hepatocytes that were to ethanol and with TNFα in an enhanced induction of several that are involved in apoptotic Hepatology. PubMed Scopus Google Scholar), the possibility that that activation of caspase 3 might as for liver is of increased hepatocyte in and with liver damage J. 1997; Full Text PDF PubMed Scopus Google Scholar, R.D. J. J. 1993; PubMed Scopus Google Scholar, L. A. J. 20: Full Text PDF PubMed Scopus Google Scholar, Alcohol. 1995; PubMed Scopus Google Scholar), the of alcohol-induced hepatocyte and inflammation Liver Dis. 1986; PubMed Scopus Google Scholar). such have been to P. and C. S. Liver Dis. Scholar). is to that enhanced vulnerability to TNF-mediated during in vivo in ethanol is known to potentiate TNF-related liver of that of TNF-mediated liver injury not the activation of procaspase that increased liver damage in ethanol-fed mice acute induction of responses, and protect hepatocytes from LPS exposure Hepatology. PubMed Scopus Google Y. T. C. R. J. 1998; PubMed Scopus Google Scholar, 1997; PubMed Scopus Google Scholar, D. E. Cell PubMed Scopus Google Scholar). in this in vivo of liver is that ethanol exposure apoptotic the activation of procaspase 8 and as an caspase for apoptosis, and the is for procaspase 3 activation and in many C. P. J. A. R. PubMed Scopus Google Scholar, E. H. J. J. J. Immunol. PubMed Scopus Google Scholar, C. A. S. C. PubMed Scopus Google Scholar, J. 20: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, H. H. J. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar). Consistent with this were to increased cytochrome c or oligonucleosomal DNA in ethanol-fed mice, these liver damage the controls. these suggest that enhanced might not the for liver is by from A. C. E. A. J.C. Gastroenterology. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), that hepatocytes from ethanol-fed are in mitochondrial after with TNFα in large of and that ethanol potentiates TNF-mediated hepatocyte necrosis is not with other that ethanol potentiates hepatocyte Hepatology. PubMed Scopus Google Scholar), of ethanol can by in factors that responses to other cytokines are of TNFα K.J. Cerami A. Annu. Rev. Cell Biol. 1993; 9: 317-343Crossref PubMed Scopus (760) Google Scholar). These factors are by hepatic J. PubMed Scopus Google Scholar) and are not in hepatocyte of liver that in vivo exposure to ethanol and induction of several cytokines that inhibit apoptosis. of these the of to the of and the of apoptotic that are by these Dubois S. Y. Google Scholar). in mice, and other cytokines may apoptotic responses that in hepatocytes without these are to evaluate this possibility ethanol exposure also the of factors that apoptosis. chronic of ethanol hepatic mitochondrial and in and Alcohol PubMed Scopus Google Scholar, C.P. Scholar). the of liver in the most of liver hepatic the most injury after hepatocytes in of the liver are and (4.Thurman R.G. Ji S. Matsumura T. Lemasters J.J. Fundam. Appl. Toxicol. 1984; 4: 125-133Crossref PubMed Google Scholar, 5.Israel Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Scholar). in might J.J. T. Y. J. PubMed Scopus Google Scholar) the of caspase 3 activation not occur when a S. P. J. Med. 1997; PubMed Scopus Google Scholar). that the of that and this to and necrosis Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Y. S. Y. 1997; Google Scholar, G. Annu. Rev. 1998; PubMed Scopus Google Scholar). of the hepatic liver and to inflammatory to the liver A. R. PubMed Scopus Google Scholar, J. T. Gastroenterology. Full Text PDF PubMed Scopus Google Scholar, G. J. Williams R. Hepatology. 1993; PubMed Scopus Google Scholar), in the of (10.Day C.P. James O. Gastroenterology. 1998; 114: 842-845Abstract Full Text Full Text PDF PubMed Scopus (3406) Google Scholar). Because the liver and other for hepatocyte and hypoxia-reoxygenation J. R. In PubMed Scopus Google Scholar, H. Scopus Google Scholar, R.B. A. J. PubMed Scopus Google Scholar, H.J. 1992; PubMed Scopus Google Scholar, J.C. D. J. PubMed Scopus Google Scholar, A. L. J. G. A. Cell PubMed Scopus Google Scholar), is that ethanol-exposed hepatocytes with can this Thus, only the liver with are likely to from is not by hepatocytes from to ethanol in of ethanol are not to the of mitochondrial toxicity that hepatic during chronic in vivo exposure to ethanol Biol. Med. PubMed Scopus Google Scholar). to hepatocyte for hepatocytes are other have for S. J. 1997; PubMed Scopus Google Scholar) and might not mitochondrial that with are in the in a that the apoptotic in hepatocyte not the or of hepatocytes in is to the in to in vivo of chronic ethanol exposure Alcohol PubMed Scopus Google Scholar, C.P. Scholar). in has that the in vivo suggest that of caspase 3 may to in this not protect alcohol from liver and to for this cause of chronic liver Although ethyl alcohol has been recognized as a significant hepatotoxin for centuries, the mechanisms involved in alcohol-induced liver disease remain uncertain. It is known that chronic alcohol ingestion potentiates liver injury inflicted by many other toxins (1.Seeff L.B. Cuccherini B.A. Zimmerman H.J. Alder E. Benjamin S.B. Ann. Intern. Med. 1986; 104: 399-404Crossref PubMed Scopus (369) Google Scholar), viral hepatitis (2.Marsano L.S. Pena L.R. Hepatogastroenterology. 1998; 45: 331-339PubMed Google Scholar, 3.Serfaty L. Chazouilleres O. Poujol-Robert A. Morand-Joubert L. Dubois C. Chretien Y. Poupon R.E. Petit J.C. Poupon R. Hepatology. 1997; 26: 776-779Crossref PubMed Scopus (116) Google Scholar), and hepatic hypoxia-reoxygenation (4.Thurman R.G. Ji S. Matsumura T. Lemasters J.J. Fundam. Appl. Toxicol. 1984; 4: 125-133Crossref PubMed Google Scholar, 5.Israel Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Scholar) or ischemia-reperfusion (6.Gao W. Connor H.D. Lemasters J.J. Mason R.P. Thurman R.G. Transplantation. 1995; 59: 674-679Crossref PubMed Scopus (60) Google Scholar) and yet fails to cause serious liver damage in most healthy adults (7.Lelbach W.K. Prog. Liver Dis. 1976; 5: 494-513PubMed Google Scholar, 8.Pequignot G. Tuyns A.S. Berta J.L. Int. J. Epidemiol. 1978; 7: 113-120Crossref PubMed Scopus (191) Google Scholar, 9.Johnson R.D. Williams R. Alcohol Alcohol. 1985; 20: 137-142PubMed Google Scholar). These clinical observations suggest that ethanol exposure enhances hepatic vulnerability to a secondary inflammatory or oxidative stress, such that serious liver injury is most likely to occur when proinflammatory/pro-oxidant factors are superimposed onto a background of ethanol use (10.Day C.P. James O. Gastroenterology. 1998; 114: 842-845Abstract Full Text Full Text PDF PubMed Scopus (3406) Google Scholar). Because tumor necrosis factor-α ((TNFα)1 and cytokines that potentiate TNF activity are the common, proximal mediators of inflammatory liver injury (11.Vassalli P. Annu. Rev. Immunol. 1992; 10: 411-452Crossref PubMed Scopus (1798) Google Scholar, 12.Tracey K.J. Cerami A. Annu. Rev. Cell Biol. 1993; 9: 317-343Crossref PubMed Scopus (760) Google Scholar, 13.Baker S.J. Reddy E.P. Oncogene. 1996; 12: 1-9PubMed Google Scholar), several laboratories have been evaluating the possibility that ethanol may sensitize hepatocytes to TNF-related toxicity (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar, G. R. Alcohol. 1996; 20: PubMed Scopus Google Scholar, J.C. C. A. E. A. J. 1997; PubMed Google Scholar, H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar, Hepatology. PubMed Scopus Google Scholar). this is that ethanol enhances liver injury by lipopolysaccharide (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar), a that TNFα J. Toxicol. 1997; PubMed Scopus Google Scholar). of the that the TNF receptor mice from the liver injury that from chronic of ethanol H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar). demonstrates that TNFα is for liver disease in that mechanisms in is to the mechanisms that to TNF hepatocytes are to TNFα toxicity have been with that inhibit protein such TNFα the mitochondrial permeability transition, cytochrome c release, caspase 3 activation, and by G. A. J. Immunol. Google Scholar). Recently, and Hepatology. PubMed Scopus Google Scholar) that ethanol these of protein when or hepatocytes that have been with ethanol are to TNFα in mitochondrial permeability transition, cytochrome c release, caspase 3 activation, and Because of these cultures with mitochondrial permeability from TNF lethality, these Hepatology. PubMed Scopus Google Scholar) that ethanol the liver to injury by apoptosis. of the is to mechanisms in vivo. To ethanol and pair-fed mice were a of LPS, and liver damage as as activation of mechanisms that and inhibit were ethanol exposure enhanced liver injury these caspase 3 the increased liver damage in the ethanol-fed was not with increased cytochrome c or oligonucleosomal DNA these a the in mechanisms for ethanol hepatotoxicity and that to sensitize ethanol-exposed livers to TNF toxicity in vivo. In of TNF-mediated liver injury not caspase 3 activation, and hepatocyte to from from apoptosis. of have in that are to and in the vulnerability to alcohol-induced liver several of suggest that serious liver damage the of an inflammatory or to ethanol-exposed livers that have of factors that protect hepatocyte H. J. Med. PubMed Scopus Google Scholar). Thus, in the and cytoprotective factors the of liver damage in laboratories have this to and that can to for from many TNFα as a of liver damage (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar, G. R. Alcohol. 1996; 20: PubMed Scopus Google Scholar, J.C. C. A. E. A. J. 1997; PubMed Google Scholar, H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar, Hepatology. PubMed Scopus Google Scholar). Recent of hepatocytes that were to ethanol and with TNFα in an enhanced induction of several that are involved in apoptotic Hepatology. PubMed Scopus Google Scholar), the possibility that that activation of caspase 3 might as for liver is of increased hepatocyte in and with liver damage J. 1997; Full Text PDF PubMed Scopus Google Scholar, R.D. J. J. 1993; PubMed Scopus Google Scholar, L. A. J. 20: Full Text PDF PubMed Scopus Google Scholar, Alcohol. 1995; PubMed Scopus Google Scholar), the of alcohol-induced hepatocyte and inflammation Liver Dis. 1986; PubMed Scopus Google Scholar). such have been to P. and C. S. Liver Dis. Scholar). is to that enhanced vulnerability to TNF-mediated during in vivo in ethanol is known to potentiate TNF-related liver of that of TNF-mediated liver injury not the activation of procaspase that increased liver damage in ethanol-fed mice acute induction of responses, and protect hepatocytes from LPS exposure Hepatology. PubMed Scopus Google Y. T. C. R. J. 1998; PubMed Scopus Google Scholar, 1997; PubMed Scopus Google Scholar, D. E. Cell PubMed Scopus Google Scholar). in this in vivo of liver is that ethanol exposure apoptotic the activation of procaspase 8 and as an caspase for apoptosis, and the is for procaspase 3 activation and in many C. P. J. A. R. PubMed Scopus Google Scholar, E. H. J. J. J. Immunol. PubMed Scopus Google Scholar, C. A. S. C. PubMed Scopus Google Scholar, J. 20: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, H. H. J. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar). Consistent with this were to increased cytochrome c or oligonucleosomal DNA in ethanol-fed mice, these liver damage the controls. these suggest that enhanced might not the for liver is by from A. C. E. A. J.C. Gastroenterology. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), that hepatocytes from ethanol-fed are in mitochondrial after with TNFα in large of and that ethanol potentiates TNF-mediated hepatocyte necrosis is not with other that ethanol potentiates hepatocyte Hepatology. PubMed Scopus Google Scholar), of ethanol can by in factors that responses to other cytokines are of TNFα K.J. Cerami A. Annu. Rev. Cell Biol. 1993; 9: 317-343Crossref PubMed Scopus (760) Google Scholar). These factors are by hepatic J. PubMed Scopus Google Scholar) and are not in hepatocyte of liver that in vivo exposure to ethanol and induction of several cytokines that inhibit apoptosis. of these the of to the of and the of apoptotic that are by these Dubois S. Y. Google Scholar). in mice, and other cytokines may apoptotic responses that in hepatocytes without these are to evaluate this possibility ethanol exposure also the of factors that apoptosis. chronic of ethanol hepatic mitochondrial and in and Alcohol PubMed Scopus Google Scholar, C.P. Scholar). the of liver in the most of liver hepatic the most injury after hepatocytes in of the liver are and (4.Thurman R.G. Ji S. Matsumura T. Lemasters J.J. Fundam. Appl. Toxicol. 1984; 4: 125-133Crossref PubMed Google Scholar, 5.Israel Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Scholar). in might J.J. T. Y. J. PubMed Scopus Google Scholar) the of caspase 3 activation not occur when a S. P. J. Med. 1997; PubMed Scopus Google Scholar). that the of that and this to and necrosis Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Y. S. Y. 1997; Google Scholar, G. Annu. Rev. 1998; PubMed Scopus Google Scholar). of the hepatic liver and to inflammatory to the liver A. R. PubMed Scopus Google Scholar, J. T. Gastroenterology. Full Text PDF PubMed Scopus Google Scholar, G. J. Williams R. Hepatology. 1993; PubMed Scopus Google Scholar), in the of (10.Day C.P. James O. Gastroenterology. 1998; 114: 842-845Abstract Full Text Full Text PDF PubMed Scopus (3406) Google Scholar). Because the liver and other for hepatocyte and hypoxia-reoxygenation J. R. In PubMed Scopus Google Scholar, H. Scopus Google Scholar, R.B. A. J. PubMed Scopus Google Scholar, H.J. 1992; PubMed Scopus Google Scholar, J.C. D. J. PubMed Scopus Google Scholar, A. L. J. G. A. Cell PubMed Scopus Google Scholar), is that ethanol-exposed hepatocytes with can this Thus, only the liver with are likely to from is not by hepatocytes from to ethanol in of ethanol are not to the of mitochondrial toxicity that hepatic during chronic in vivo exposure to ethanol Biol. Med. PubMed Scopus Google Scholar). to hepatocyte for hepatocytes are other have for S. J. 1997; PubMed Scopus Google Scholar) and might not mitochondrial that with are in the in a that the apoptotic in hepatocyte not the or of hepatocytes in is to the in to in vivo of chronic ethanol exposure Alcohol PubMed Scopus Google Scholar, C.P. Scholar). in has that the in vivo suggest that of caspase 3 may to in this not protect alcohol from liver and to for this cause of chronic liver of have in that are to and in the vulnerability to alcohol-induced liver several of suggest that serious liver damage the of an inflammatory or to ethanol-exposed livers that have of factors that protect hepatocyte H. J. Med. PubMed Scopus Google Scholar). Thus, in the and cytoprotective factors the of liver damage in laboratories have this to and that can to for from many TNFα as a of liver damage (14.Honchel R. Ray R.B. Marsano L. Cohen D. E. S. Alcohol. 1992; PubMed Scopus Google Scholar, G. R. Alcohol. 1996; 20: PubMed Scopus Google Scholar, J.C. C. A. E. A. J. 1997; PubMed Google Scholar, H. Thurman R.G. Gastroenterology. Full Text Full Text PDF PubMed Scopus Google Scholar, Hepatology. PubMed Scopus Google Scholar). Recent of hepatocytes that were to ethanol and with TNFα in an enhanced induction of several that are involved in apoptotic Hepatology. PubMed Scopus Google Scholar), the possibility that that activation of caspase 3 might as for liver is of increased hepatocyte in and with liver damage J. 1997; Full Text PDF PubMed Scopus Google Scholar, R.D. J. J. 1993; PubMed Scopus Google Scholar, L. A. J. 20: Full Text PDF PubMed Scopus Google Scholar, Alcohol. 1995; PubMed Scopus Google Scholar), the of alcohol-induced hepatocyte and inflammation Liver Dis. 1986; PubMed Scopus Google Scholar). such have been to P. and C. S. Liver Dis. Scholar). is to that enhanced vulnerability to TNF-mediated during in vivo in ethanol is known to potentiate TNF-related liver of that of TNF-mediated liver injury not the activation of procaspase that increased liver damage in ethanol-fed mice acute induction of responses, and protect hepatocytes from LPS exposure Hepatology. PubMed Scopus Google Y. T. C. R. J. 1998; PubMed Scopus Google Scholar, 1997; PubMed Scopus Google Scholar, D. E. Cell PubMed Scopus Google Scholar). in this in vivo of liver is that ethanol exposure apoptotic the activation of procaspase 8 and as an caspase for apoptosis, and the is for procaspase 3 activation and in many C. P. J. A. R. PubMed Scopus Google Scholar, E. H. J. J. J. Immunol. PubMed Scopus Google Scholar, C. A. S. C. PubMed Scopus Google Scholar, J. 20: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, H. H. J. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar). Consistent with this were to increased cytochrome c or oligonucleosomal DNA in ethanol-fed mice, these liver damage the controls. these suggest that enhanced might not the for liver is by from A. C. E. A. J.C. Gastroenterology. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), that hepatocytes from ethanol-fed are in mitochondrial after with TNFα in large of and that ethanol potentiates TNF-mediated hepatocyte necrosis is not with other that ethanol potentiates hepatocyte Hepatology. PubMed Scopus Google Scholar), of ethanol can by in factors that responses to other cytokines are of TNFα K.J. Cerami A. Annu. Rev. Cell Biol. 1993; 9: 317-343Crossref PubMed Scopus (760) Google Scholar). These factors are by hepatic J. PubMed Scopus Google Scholar) and are not in hepatocyte of liver that in vivo exposure to ethanol and induction of several cytokines that inhibit apoptosis. of these the of to the of and the of apoptotic that are by these Dubois S. Y. Google Scholar). in mice, and other cytokines may apoptotic responses that in hepatocytes without these are to evaluate this possibility ethanol exposure also the of factors that apoptosis. chronic of ethanol hepatic mitochondrial and in and Alcohol PubMed Scopus Google Scholar, C.P. Scholar). the of liver in the most of liver hepatic the most injury after hepatocytes in of the liver are and (4.Thurman R.G. Ji S. Matsumura T. Lemasters J.J. Fundam. Appl. Toxicol. 1984; 4: 125-133Crossref PubMed Google Scholar, 5.Israel Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Scholar). in might J.J. T. Y. J. PubMed Scopus Google Scholar) the of caspase 3 activation not occur when a S. P. J. Med. 1997; PubMed Scopus Google Scholar). that the of that and this to and necrosis Y. Orrego H. Recent Dev. Alcohol. 1984; 2: 119-133Crossref PubMed Scopus (28) Google Y. S. Y. 1997; Google Scholar, G. Annu. Rev. 1998; PubMed Scopus Google Scholar). of the hepatic liver and to inflammatory to the liver A. R. PubMed Scopus Google Scholar, J. T. Gastroenterology. Full Text PDF PubMed Scopus Google Scholar, G. J. Williams R. Hepatology. 1993; PubMed Scopus Google Scholar), in the of (10.Day C.P. James O. Gastroenterology. 1998; 114: 842-845Abstract Full Text Full Text PDF PubMed Scopus (3406) Google Scholar). Because the liver and other for hepatocyte and hypoxia-reoxygenation J. R. In PubMed Scopus Google Scholar, H. Scopus Google Scholar, R.B. A. J. PubMed Scopus Google Scholar, H.J. 1992; PubMed Scopus Google Scholar, J.C. D. J. PubMed Scopus Google Scholar, A. L. J. G. A. Cell PubMed Scopus Google Scholar), is that ethanol-exposed hepatocytes with can this Thus, only the liver with are likely to from is not by hepatocytes from to ethanol in of ethanol are not to the of mitochondrial toxicity that hepatic during chronic in vivo exposure to ethanol Biol. Med. PubMed Scopus Google Scholar). to hepatocyte for hepatocytes are other have for S. J. 1997; PubMed Scopus Google Scholar) and might not mitochondrial that with are in the in a that the apoptotic Thus, in hepatocyte not the or of hepatocytes in is to the in to in vivo of chronic ethanol exposure Alcohol PubMed Scopus Google Scholar, C.P. Scholar). in has that the in vivo suggest that of caspase 3 may to in this not protect alcohol from liver and to for this cause of chronic liver