- Email: [email protected]
Effect of alcohol consumption on the skin
112
Abstracts / Alcohol 39 (2006) 111e117
1
3
Consequences and mechanisms of defective neutrophil recruitment in pulmonary host defense against bacterial infections after ethanol exposure Gregory J. Bagby, Ping Zhang and Steve Nelson, Alcohol and Drug Abuse Center, Departments of Physiology and Medicine, LSU Health Sciences Center, New Orleans. LA 70112.
Identification of phospholipase A2 isoforms which contribute to binge alcohol-mediated neurodegeneration James Brown III, Nicholas Achille, Edward J. Neafsey and Michael A. Collins, Department of Cell Biology, Neurobiology & Anatomy, Loyola University Medical Center, Maywood, IL USA.
Alcohol abuse increases the incidence and severity of pulmonary infections. The respiratory system possesses an array of host defense strategies that normally function to protect the lung from invading pathogens. Excessive alcohol consumption impairs the ability of airway defenses to clear microbes entering the lungs through the air or via aspiration of pathogens that have colonized to nasopharynx. Neutrophil recruitment from the blood to the intra-alveolar compartment is often required for the effective eradication of invading bacteria. It has been recognized for more than 50 years that alcohol intoxication impairs neutrophil functions and that their migration to sites of infection is one important mechanism by which alcohol abuse increases host susceptibility to infections of the lung. Neutrophil migration from the intravascular compartment to a locus of infection within the lungs is a complex process involving multiple steps that include margination, adhesion, and transendothelial/epithelial migration. As neutropenia is observed in alcoholics, delivery of neutrophils to infected lung is also compromised by insufficient production of neutrophils by hematopoietic tissues. In rodent models of pulmonary inflammation and bacterial infection, we have shown that intoxicating doses of ethanol impair production of proinflammatory cytokine such as TNF, CXC chemokines and G-CSF. Host defense augmentation strategies using G-CSF, IFN and CXC chemokines show that ethanol-induced suppression of cytokine production is in part responsible for impaired neutrophil recruitment to the intra-alveolar compartment and granulopoiesis. However, recent studies indicate that neutrophil recruitment in response to chemotactic signals within the lung as well as the granulopoietic response to G-CSF is also impaired. Understanding the mechanisms by which ethanol intoxication attenuates neutrophil delivery to sites of infection might identify therapeutic approaches to improve neutrophil production and function in response to invading pathogens. (Supported by NIAAA P60 AA09803).
Excessive alcohol consumption for several days in a small time frame (binge-drinking) is known to cause significant loss of neuronal tissue. Previous studies in our lab have shown that rat hippocampal-entorhinocortical (HEC) slice cultures binge-treated for 6 days with 100-150 mM alcohol exhibit cellular swelling (edema) followed by regional neurodegeneration. A potential signaling pathway that is common to both cell swelling and neurodegeneration in other models is activation of the phospholipase A2 (PLA2) pathway and subsequent release of arachidonic acid (AA). Using our HEC model, we have also observed an increase in release of AA following binge alcohol treatment and an inhibition of binge alcohol-induced neurotoxicity by the non-specific PLA2 inhibitor, mepacrine. What is unclear is the identity of the class of PLA2 isoforms involved in this release of arachidonic acid and subsequent neurodegeneration. We show here that the specific secretory PLA2 inhibitor (sPLA2), manoalide, caused a concentration-dependent inhibition of binge alcohol-mediated neurodegeneration in HEC slices. Results with use of the specific inhibitors of cytosolic Ca2þ -dependent phospholipase A2 (cPLA2), or Ca2þ -independent PLA2 (iPLA2) (AACOCF3 and bromoenol lactone, respectively), or the dual inhibitor of both cPLA2 and iPLA2, methylarachidonyl fluorophosphate (MAFP) suggest that cPLA2 and iPLA2 do not contribute to binge alcohol-mediated neurodegeneration (though at press time, the bromoenol lactone data is very preliminary). Of the known isoforms of sPLA2 (Groups I, IIa-f, III, V, X, XII), initial data suggests that Group I and II isoforms of sPLA2 do not contribute to binge alcohol-mediated neurodegeneration. Taken together, sPLA2, but not c- or (possibly) iPLA2, appear to play a role in the mechanism development of binge alcohol-mediated neurodegeneration. (Supported by NIH T32 AA13527, the Loyola University Medical Center Potts fund, and the Loyola University Alcohol Research Program.).
2
4
Effect of alcohol consumption on the skin Rhonda M. Brand and Jessica L. Jendrzejewski, Department of Internal Medicine, Evanston Northwestern Healthcare and Feinberg School of Medicine at Northwestern University, Evanston, IL.
Chronic ethanol consumption results in increased TNF-a production by inflammatory macrophages in mice infected with Salmonella typhimurium Michael P. Burrows and Thomas R. Jerrells, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.
Ethanol is well known as a topical penetration enhancer and is used in commercially formulated drug delivery patches. This combined with the fact that alcohol ingestion is correlated with a number of skin diseases led to studies examining whether the enhancement properties of ethanol on chemical penetration occur if alcohol is consumed instead of applied topically. Wistar rats were given ethanol either in the Lieber-DeCarli diet for 12 weeks or by gavage at doses of 10, 6, 4.3, 3 or 1.5 g/kg prior to transdermal penetration studies. Both chronic and acute ethanol consumption increase transdermal penetration through rat skin resulting in significantly higher exposure of xenobiotics including paraquat, DEET, dimethyl formamide and 2,4-D (p!0.05). In order to elucidate the mechanism by which ethanol alters skin barrier function, both dermal blood flow and transepidermal water loss (TEWL) were non-invasively monitored for each feeding model. Dermal blood flow was increased in both chronic and acute exposure (p!0.05) but changes in barrier lipids as determined by TEWL were only seen after chronic dosing (p!0.05). Furthermore, we have also demonstrated that chronic ethanol ingestion leads to changes in the skin that are similar to those that occur in alcoholic liver disease including increased alcohol and aldehyde dehydrogenase as well as lipid peroxidation. All parameters tested in chronically treated animals remain elevated for at least 2 weeks after termination of ethanol consumption, demonstrating that the changes in the skin induced by ethanol are not immediately reversible and that the epidermis must ‘‘turn over’’ or be replaced with new cells in order to reverse the effects. Even changes triggered by acute ethanol consumption remained 24 hours after ingestion. These studies demonstrate that both chronic and acute ethanol consumption can compromise the dermal barrier and that the effects last beyond the duration of ethanol in the blood stream and provide a starting point for examination of the link between ethanol ingestion and skin disorders associated with alcohol use. (Supported by NIH R21 AA015199-01).
Alcohol abuse and the sequelae of alcohol abuse are major health issues in the United States and around the world. Human beings who chronically abuse alcohol have alterations in their immune system, most notably a suppression of the immune response to pathogenic organisms. Alcohol consumption by mice is associated with a reduced ability of the host to clear S. typhimurium from the liver, which results in increased and prolonged inflammation. Because inflammatory macrophages (IMf) are the primary source of TNF-a during the early response to Salmonella typhimurium we tested the hypothesis that IMfs isolated from EtOH-fed mice produce more TNF-a than control IMf, resulting in increased liver damage. C57BL/6 mice were provided 20% EtOH in H2O for 14 weeks. Mice were euthanized 1-4 days after infection, and serum and liver tissue collected. Mononuclear cells were isolated by percoll gradient and IMf were purified by magnetic bead separation. IMf were cultured ex vivo and stimulated with toll-like receptor ligands. Liver damage was assessed by histologic examination and serum alanine aminotransferase (ALT) concentration, and serum cytokine concentrations were determined by cytometric bead array. IMf isolated from the liver of EtOH-fed mice produced higher concentrations of TNF-a when compared with controls (p!0.05). TNF-a in the serum of EtOH-fed mice was lower than controls 3 days (p!0.01) after infection and higher than controls at 4 days (p!0.001). IFN-g (p!0.05) and IL-6 (p!0.01) in the serum of EtOH-fed mice were lower than controls 3 days after infection. Additionally, mice fed EtOH and infected with S. typhimurium had a more severe hepatitis than control mice 3 (p!0.01) and 4 (p!0.001) days after infection, as indicated by serum ALT concentration. These data support the suggestion that mechanisms altered by EtOH in resident Mf may exist in IMf, and result in increased TNF-a production and liver damage in Salmonella-infected mice. (Supported by RO1 AA 12450 and T32 AA 7582).
Abstracts / Alcohol 39 (2006) 111e117
1
3
Consequences and mechanisms of defective neutrophil recruitment in pulmonary host defense against bacterial infections after ethanol exposure Gregory J. Bagby, Ping Zhang and Steve Nelson, Alcohol and Drug Abuse Center, Departments of Physiology and Medicine, LSU Health Sciences Center, New Orleans. LA 70112.
Identification of phospholipase A2 isoforms which contribute to binge alcohol-mediated neurodegeneration James Brown III, Nicholas Achille, Edward J. Neafsey and Michael A. Collins, Department of Cell Biology, Neurobiology & Anatomy, Loyola University Medical Center, Maywood, IL USA.
Alcohol abuse increases the incidence and severity of pulmonary infections. The respiratory system possesses an array of host defense strategies that normally function to protect the lung from invading pathogens. Excessive alcohol consumption impairs the ability of airway defenses to clear microbes entering the lungs through the air or via aspiration of pathogens that have colonized to nasopharynx. Neutrophil recruitment from the blood to the intra-alveolar compartment is often required for the effective eradication of invading bacteria. It has been recognized for more than 50 years that alcohol intoxication impairs neutrophil functions and that their migration to sites of infection is one important mechanism by which alcohol abuse increases host susceptibility to infections of the lung. Neutrophil migration from the intravascular compartment to a locus of infection within the lungs is a complex process involving multiple steps that include margination, adhesion, and transendothelial/epithelial migration. As neutropenia is observed in alcoholics, delivery of neutrophils to infected lung is also compromised by insufficient production of neutrophils by hematopoietic tissues. In rodent models of pulmonary inflammation and bacterial infection, we have shown that intoxicating doses of ethanol impair production of proinflammatory cytokine such as TNF, CXC chemokines and G-CSF. Host defense augmentation strategies using G-CSF, IFN and CXC chemokines show that ethanol-induced suppression of cytokine production is in part responsible for impaired neutrophil recruitment to the intra-alveolar compartment and granulopoiesis. However, recent studies indicate that neutrophil recruitment in response to chemotactic signals within the lung as well as the granulopoietic response to G-CSF is also impaired. Understanding the mechanisms by which ethanol intoxication attenuates neutrophil delivery to sites of infection might identify therapeutic approaches to improve neutrophil production and function in response to invading pathogens. (Supported by NIAAA P60 AA09803).
Excessive alcohol consumption for several days in a small time frame (binge-drinking) is known to cause significant loss of neuronal tissue. Previous studies in our lab have shown that rat hippocampal-entorhinocortical (HEC) slice cultures binge-treated for 6 days with 100-150 mM alcohol exhibit cellular swelling (edema) followed by regional neurodegeneration. A potential signaling pathway that is common to both cell swelling and neurodegeneration in other models is activation of the phospholipase A2 (PLA2) pathway and subsequent release of arachidonic acid (AA). Using our HEC model, we have also observed an increase in release of AA following binge alcohol treatment and an inhibition of binge alcohol-induced neurotoxicity by the non-specific PLA2 inhibitor, mepacrine. What is unclear is the identity of the class of PLA2 isoforms involved in this release of arachidonic acid and subsequent neurodegeneration. We show here that the specific secretory PLA2 inhibitor (sPLA2), manoalide, caused a concentration-dependent inhibition of binge alcohol-mediated neurodegeneration in HEC slices. Results with use of the specific inhibitors of cytosolic Ca2þ -dependent phospholipase A2 (cPLA2), or Ca2þ -independent PLA2 (iPLA2) (AACOCF3 and bromoenol lactone, respectively), or the dual inhibitor of both cPLA2 and iPLA2, methylarachidonyl fluorophosphate (MAFP) suggest that cPLA2 and iPLA2 do not contribute to binge alcohol-mediated neurodegeneration (though at press time, the bromoenol lactone data is very preliminary). Of the known isoforms of sPLA2 (Groups I, IIa-f, III, V, X, XII), initial data suggests that Group I and II isoforms of sPLA2 do not contribute to binge alcohol-mediated neurodegeneration. Taken together, sPLA2, but not c- or (possibly) iPLA2, appear to play a role in the mechanism development of binge alcohol-mediated neurodegeneration. (Supported by NIH T32 AA13527, the Loyola University Medical Center Potts fund, and the Loyola University Alcohol Research Program.).
2
4
Effect of alcohol consumption on the skin Rhonda M. Brand and Jessica L. Jendrzejewski, Department of Internal Medicine, Evanston Northwestern Healthcare and Feinberg School of Medicine at Northwestern University, Evanston, IL.
Chronic ethanol consumption results in increased TNF-a production by inflammatory macrophages in mice infected with Salmonella typhimurium Michael P. Burrows and Thomas R. Jerrells, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.
Ethanol is well known as a topical penetration enhancer and is used in commercially formulated drug delivery patches. This combined with the fact that alcohol ingestion is correlated with a number of skin diseases led to studies examining whether the enhancement properties of ethanol on chemical penetration occur if alcohol is consumed instead of applied topically. Wistar rats were given ethanol either in the Lieber-DeCarli diet for 12 weeks or by gavage at doses of 10, 6, 4.3, 3 or 1.5 g/kg prior to transdermal penetration studies. Both chronic and acute ethanol consumption increase transdermal penetration through rat skin resulting in significantly higher exposure of xenobiotics including paraquat, DEET, dimethyl formamide and 2,4-D (p!0.05). In order to elucidate the mechanism by which ethanol alters skin barrier function, both dermal blood flow and transepidermal water loss (TEWL) were non-invasively monitored for each feeding model. Dermal blood flow was increased in both chronic and acute exposure (p!0.05) but changes in barrier lipids as determined by TEWL were only seen after chronic dosing (p!0.05). Furthermore, we have also demonstrated that chronic ethanol ingestion leads to changes in the skin that are similar to those that occur in alcoholic liver disease including increased alcohol and aldehyde dehydrogenase as well as lipid peroxidation. All parameters tested in chronically treated animals remain elevated for at least 2 weeks after termination of ethanol consumption, demonstrating that the changes in the skin induced by ethanol are not immediately reversible and that the epidermis must ‘‘turn over’’ or be replaced with new cells in order to reverse the effects. Even changes triggered by acute ethanol consumption remained 24 hours after ingestion. These studies demonstrate that both chronic and acute ethanol consumption can compromise the dermal barrier and that the effects last beyond the duration of ethanol in the blood stream and provide a starting point for examination of the link between ethanol ingestion and skin disorders associated with alcohol use. (Supported by NIH R21 AA015199-01).
Alcohol abuse and the sequelae of alcohol abuse are major health issues in the United States and around the world. Human beings who chronically abuse alcohol have alterations in their immune system, most notably a suppression of the immune response to pathogenic organisms. Alcohol consumption by mice is associated with a reduced ability of the host to clear S. typhimurium from the liver, which results in increased and prolonged inflammation. Because inflammatory macrophages (IMf) are the primary source of TNF-a during the early response to Salmonella typhimurium we tested the hypothesis that IMfs isolated from EtOH-fed mice produce more TNF-a than control IMf, resulting in increased liver damage. C57BL/6 mice were provided 20% EtOH in H2O for 14 weeks. Mice were euthanized 1-4 days after infection, and serum and liver tissue collected. Mononuclear cells were isolated by percoll gradient and IMf were purified by magnetic bead separation. IMf were cultured ex vivo and stimulated with toll-like receptor ligands. Liver damage was assessed by histologic examination and serum alanine aminotransferase (ALT) concentration, and serum cytokine concentrations were determined by cytometric bead array. IMf isolated from the liver of EtOH-fed mice produced higher concentrations of TNF-a when compared with controls (p!0.05). TNF-a in the serum of EtOH-fed mice was lower than controls 3 days (p!0.01) after infection and higher than controls at 4 days (p!0.001). IFN-g (p!0.05) and IL-6 (p!0.01) in the serum of EtOH-fed mice were lower than controls 3 days after infection. Additionally, mice fed EtOH and infected with S. typhimurium had a more severe hepatitis than control mice 3 (p!0.01) and 4 (p!0.001) days after infection, as indicated by serum ALT concentration. These data support the suggestion that mechanisms altered by EtOH in resident Mf may exist in IMf, and result in increased TNF-a production and liver damage in Salmonella-infected mice. (Supported by RO1 AA 12450 and T32 AA 7582).