Chronic ethanol consumption induces histopathological changes and increases nitric oxide generation in the rat liver

Chronic ethanol exposure impairs alveolar leukocyte infiltration during pneumococcal pneumonia, leading to an increased bacterial burden despite increased CXCL1 and nitric oxide levels

Ethanol abuse is a risk factor for the development of pneumonia caused by Streptococcus pneumoniae, a critical pathogen for public health. The aim of this article was to investigate the inflammatory mechanisms involved in pneumococcal pneumonia that may be associated with chronic ethanol exposure. Male C57BL6/J-Unib mice were exposed to 20% (v/v) ethanol for twelve weeks and intranasally infected with 5x10⁴ CFU of S. pneumoniae. Twenty-four hours after infection, lungs, bronchoalveolar lavage and blood samples were obtained to assess the consequences of chronic ethanol exposure during infection. Alcohol-fed mice showed increased production of nitric oxide and CXCL1 in alveoli and plasma during pneumococcal pneumonia. Beside this, ethanol-treated mice exhibited a decrease in leukocyte infiltration into the alveoli and reduced frequency of severe lung inflammation, which was associated with an increase in bacterial load. Curiously, no changes were observed in survival after infection. Taken together, these results demonstrate that chronic ethanol exposure alters the inflammatory response during S. pneumoniae lung infection in mice with a reduction in the inflammatory infiltrate even in the presence of higher levels of the chemoattractant CXCL1.

Anti-Inflammatory Mechanisms of Novel Synthetic Ruthenium Compounds

Inflammation is the primary biological reaction to induce severe infection or injury in the immune system. Control of different inflammatory cytokines, such as nitric oxide (NO), interleukins (IL), tumor necrosis factor alpha-(TNF-α), noncytokine mediator, prostaglandin E2 (PGE2), mitogen activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB), facilitates anti-inflammatory effect of different substances. Coordination metal complexes have been applied as metallo-drugs. Several metal complexes have found to possess potent biological activities, especially anticancer, cardioprotective, chondroprotective and anti-parasitosis activities. Among the metallo drugs, ruthenium-based (Ru) complexes have paid much attention in clinical applications. Despite the kinetic nature of Ru complexes is similar to platinum in terms of cell division events, their toxic effect is lower than that of cisplatin. This paper reviews the anti-inflammatory effect of novel synthetic Ru complexes with potential molecular mechanisms that are actively involved.

Columbianadin Dampens In Vitro Inflammatory Actions and Inhibits Liver Injury via Inhibition of NF-κB/MAPKs: Impacts on ∙OH Radicals and HO-1 Expression

Columbianadin (CBN), a natural coumarin isolated from Angelica decursiva, is reported to have numerous biological activities, including anticancer and platelet aggregation inhibiting properties. Here, we investigated CBN’s anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell activation and deciphered the signaling process, which could be targeted by CBN as part of the mechanisms. Using a mouse model of LPS-induced acute liver inflammation, the CBN effects were examined by distinct histologic methods using trichrome, reticulin, and Weigert’s resorcin fuchsin staining. The result showed that CBN decreased LPS-induced expressions of TNF-α, IL-1β, and iNOS and NO production in RAW 264.7 cells and mouse liver. CBN inhibited LPS-induced ERK and JNK phosphorylation, increased IκBα levels, and inhibited NF-κB p65 phosphorylation and its nuclear translocation. Application of inhibitors for ERK (PD98059) and JNK (SP600125) abolished the LPS-induced effect on NF-κB p65 phosphorylation, which indicated that ERK and JNK signaling pathways were involved in CBN-mediated inhibition of NF-κB activation. Treatment with CBN decreased hydroxyl radical (^•OH) generation and increased HO-1 expression in RAW 264.7 cells. Furthermore, LPS-induced liver injury, as indicated by elevated serum levels of liver marker enzymes (aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) and histopathological alterations, were reversed by CBN. This work demonstrates the utility of CBN against LPS-induced inflammation, liver injury, and oxidative stress by targeting JNK/ERK and NF-κB signaling pathways.

Rapid Enkephalin Delivery Using Exosomes to Promote Neurons Recovery in Ischemic Stroke by Inhibiting Neuronal p53/Caspase-3

No pharmacological treatment is currently available to protect brain from neuronal damage after ischemic stroke. Recent studies found that enkephalin may play an important role in neuron regeneration. We assembled a homogeneous size vesicle constituted by transferrin, exosomes, and enkephalin. Immunofluorescence assay showed that transferrin was combined with the exosomes and enkephalin was packaged into the vesicle; thus this complex was called tar-exo-enkephalin. In vitro studies were performed using rat primary hippocampal neurons and the results showed that enkephalin decreased p53 and caspase-3 levels to 47.6% and 67.2%, respectively, compared to neurons treated with glutamate, thus inhibiting neuron apoptosis caused by glutamate. An in vivo experiment in rats was also carried out using a transient middle cerebral artery occlusion (tMCAO)/reperfusion model and tar-exo-enkephalin treatment was performed after tMCAO. The results showed that tar-exo-enkephalin crossed the blood brain barrier (BBB) and decreased the levels of LDH, p53, caspase-3, and NO by 41.9, 52.6, 45.5, and 57.9% compared to the tMCAO rats, respectively. In addition, tar-exo-enkephalin improved brain neuron density and neurological score after tMCAO. These findings suggest that the use of exogenous enkephalin might promote neurological recovery after stroke.

Anti-inflammatory and hepatoprotective effects of exopolysaccharides isolated from Pleurotus geesteranus on alcohol-induced liver injury

The present work investigated the hepatoprotective role of exopolysaccharides (EPS) isolated from the mushroom Pleurotus geesteranus with respect to alcohol-induced liver injury in mice. Based on a physico-chemical analysis, the EPS produced by Pleurotus geesteranus was identified as a heteropolysaccharide with α-glycosidic bond. The results revealed that prophylactic application of the EPS reduces detrimental alcoholic effects on the liver. This observation was followed by decreased levels of total cholesterol, triglycerides, CYP2E1 and pro-inflammatory mediators (TNF-α, IL-6, IL-1β, COX-2, NO and iNOS) in the liver homogenates, suggesting that the EPS exhibits anti-inflammatory and hepatoprotective effects. Moreover, the increased activity of hepatic enzymes (superoxide dismutase, glutathione peroxidase and catalase) and reduced lipid peroxidation status indicated that the antioxidative effect of the EPS contributes to alleviation of liver injury. Therefore, this study reports that the EPS produced by Pleurotus geesteranus could be considered a potential natural drug or functional food supplement for the prevention of liver damage.

Dysregulated mitogen-activated protein kinase and matrix metalloproteinase in ethanol-induced cavernosal dysfunction

We evaluated the effects of ethanol consumption on the mitogen-activated protein kinases (MAPK) and metalloproteinases (MMP) pathways in the rat cavernosal smooth muscle (CSM). Male Wistar rats were treated with ethanol (20% v/v) for 6 weeks. Quantitative real-time polymerase chain reaction experiments showed that ethanol consumption did not alter mRNA levels of p38MAPK, SAPK/JNK, ERK1/2, MMP-2, or MMP-9 in the rat CSM. Western immunoblotting experiments revealed decreased protein expression of p38MAPK and phosphorylation of SAPK/JNK in the CSM from ethanol-treated rats. Additionally, ethanol consumption decreased the expression of MMP-2. Functional assays showed that SP600125, an inhibitor of SAPK/JNK, prevented the increase in endothelin (ET)-1-induced contraction in the CSM from ethanol-treated rats. Treatment with ethanol decreased MMP-2 activity, but did not change net MMP activity in the rat CSM. Ethanol consumption increased the circulating levels of MMP-2, MMP-9, and TIMP-2 as well as the MMP-9/TIMP-1 ratio. The major finding of our study is that ethanol consumption down-regulates both MAPK and MMP pathways in the rat CSM, whereas it increases the circulating levels of MMP-9. Additionally, we found that SAPK/JNK plays a role in ethanol-induced increase on ET-1 contraction in the isolated rat CSM.

Synergistic Interaction of Light Alcohol Administration in the Presence of Mild Iron Overload in a Mouse Model of Liver Injury: Involvement of Triosephosphate Isomerase Nitration and Inactivation

It is well known that iron overload promotes alcoholic liver injury, but the doses of iron or alcohol used in studies are usually able to induce liver injury independently. Little attention has been paid to the coexistence of low alcohol consumption and mild iron overload when either of them is insufficient to cause obvious liver damage, although this situation is very common among some people. We studied the interactive effects and the underlining mechanism of mild doses of iron and alcohol on liver injury in a mouse model. Forty eight male Kunming mice were randomly divided into four groups: control, iron (300 mg/kg iron dextran, i.p.), alcohol (2 g/kg/day ethanol for four weeks i.g.), and iron plus alcohol group. After 4 weeks of treatment, mice were sacrificed and blood and livers were collected for biochemical analysis. Protein nitration level in liver tissue was determined by immunoprecipitation and Western blot analysis. Although neither iron overload nor alcohol consumption at our tested doses can cause severe liver injury, it was found that co-administration of the same doses of alcohol and iron resulted in liver injury and hepatic dysfunction, accompanied with elevated ratio of NADH/NAD⁺, reduced antioxidant ability, increased oxidative stress, and subsequent elevated protein nitration level. Further study revealed that triosephosphate isomerase, an important glycolytic enzyme, was one of the targets to be oxidized and nitrated, which was responsible for its inactivation. These data indicate that even under low alcohol intake, a certain amount of iron overload can cause significant liver oxidative damage, and the modification of triosephosphate isomerasemight be the important underlining mechanism of hepatic dysfunction.

Fucoidan from Fucus vesiculosus protects against alcohol-induced liver damage by modulating inflammatory mediators in mice and HepG2 cells

Fucoidan is an l-fucose-enriched sulfated polysaccharide isolated from brown algae and marine invertebrates. In this study, we investigated the protective effect of fucoidan from Fucus vesiculosus on alcohol-induced murine liver damage. Liver injury was induced by oral administration of 25% alcohol with or without fucoidan (30 mg/kg or 60 mg/kg) for seven days. Alcohol administration increased serum aspartate aminotransferase and alanine aminotransferase levels, but these increases were suppressed by the treatment of fucoidan. Transforming growth factor beta 1 (TGF-β1), a liver fibrosis-inducing factor, was highly expressed in the alcohol-fed group and human hepatoma HepG2 cell; however, the increase in TGF-β1 expression was reduced following fucoidan administration. Treatment with fucoidan was also found to significantly reduce the production of inflammation-promoting cyclooygenase-2 and nitric oxide, while markedly increasing the expression of the hepatoprotective enzyme, hemeoxygenase-1, on murine liver and HepG2 cells. Taken together, the antifibrotic and anti-inflammatory effects of fucoidan on alcohol-induced liver damage may provide valuable insights into developing new therapeutics or interventions.

Integrating knowledge representation and quantitative modelling in physiology

A wealth of potentially shareable resources, such as data and models, is being generated through the study of physiology by computational means. Although in principle the resources generated are reusable, in practice, few can currently be shared. A key reason for this disparity stems from the lack of consistent cataloguing and annotation of these resources in a standardised manner. Here, we outline our vision for applying community-based modelling standards in support of an automated integration of models across physiological systems and scales. Two key initiatives, the Physiome Project and the European contribution - the Virtual Phsysiological Human Project, have emerged to support this multiscale model integration, and we focus on the role played by two key components of these frameworks, model encoding and semantic metadata annotation. We present examples of biomedical modelling scenarios (the endocrine effect of atrial natriuretic peptide, and the implications of alcohol and glucose toxicity) to illustrate the role that encoding standards and knowledge representation approaches, such as ontologies, could play in the management, searching and visualisation of physiology models, and thus in providing a rational basis for healthcare decisions and contributing towards realising the goal of of personalized medicine.