Higher neutrophil infiltration mediated by osteopontin is a likely contributing factor to the increased susceptibility of females to alcoholic liver disease

Alcoholic liver disease (ALD) is a major public health problem in the United States and women are known to be more susceptible to ALD. However, the precise mechanism for increased susceptibility of females to ALD is not completely understood. The present study is based on the hypothesis that induction of osteopontin (OPN), a matricellular protein, is the likely contributing factor for higher neutrophil recruitment in females during alcoholic steatohepatitis (ASH). ASH was induced in male and female Sprague-Dawley rats by feeding them a Lieber-DeCarli diet containing ethanol (EtOH) for 6 weeks, followed by a single injection of lipopolysaccharide (LPS, 10 mg/kg, ip). Liver injury, measured by plasma transaminase elevations and confirmed by haematoxylin and eosin-stained liver sections, revealed approximately 25-fold higher liver injury in the female ASH model compared with the males. Although steatosis, necrosis, and neutrophil infiltration were evident in both male and female rats, hepatic neutrophilic necrotic foci were noted as early as 2 h after LPS injection in the EtOH-treated female rats. Hepatic neutrophil infiltration correlated with higher expression of cleaved (cOPN) and uncleaved OPN in the EtOH + LPS-treated female rats compared with the males. OPN secretion was localized predominantly in the biliary epithelium and females had significantly higher OPN mRNA than their male counterparts in the ASH model. The ability of OPN to attract neutrophils was further confirmed in vivo, in a peritonitis rat model, and by neutralizing OPN (nOPN) antibody experiments. Hepatic neutrophil infiltration was largely inhibited ( approximately 50%) by nOPN antibody. Flow cytometry experiments revealed OPN-mediated up-regulation of the CD11b neutrophil adhesion molecule. In conclusion, these data suggest that higher hepatic expression of OPN is the likely reason for higher and early hepatic neutrophil infiltration making females more susceptible to ALD during ASH.     

The effect of 1,25-dihydroxyvitamin D3 on liver damage,oxidative stress,and advanced glycation end products in experimental nonalcoholic- and alcoholic- fatty liver disease

Background/aim Oxidative stress and advanced glycation end products (AGEs) formation are proposed as effective mechanisms in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD). 1,25(OH)2D3 was proposed to have antioxidant, antiinflammatory and antiglycation properties. In this study, the effect of 1,25(OH)2D3 treatment on oxidative stress parameters and AGEs levels together with hepatic histopathology was investigated in high fructose (HFr) or ethanol (EtOH)-treated rats. Materials and methods Rats were treated with fructose (30%) or ethanol (5-20%) in drinking water with and without 1,25(OH)2D3 treatment (5 µg/kg two times a week) for 8 weeks. Insulin resistance (IR), oxidative stress parameters, AGEs, triglyceride (TG), and hydroxyproline (Hyp) levels together with histopathology were investigated in the liver. Results1,25(OH)2D3 decreased hepatic reactive oxygen species, lipid and protein oxidation products together with histopathological improvements in HFr- and EtOH-treated rats. 1,25(OH)2D3 treatment was observed to decrease significantly serum and hepatic AGEs in HFr group, and hepatic AGEs in EtOH group.Conclusion Our results clearly show that 1,25(OH)2 D3 treatment may be useful in the alleviation of hepatic lesions by decreasing glycooxidant stress in both NAFLD and ALD models created by HFr- and EtOH-treated rats, respectively.     

Myeloid Mixed Lineage Kinase 3 Contributes to Chronic Ethanol-Induced Inflammation and Hepatocyte Injury in Mice

Proinflammatory activity of hepatic macrophages plays a key role during progression of alcoholic liver disease (ALD). Since mixed lineage kinase 3 (MLK3)-dependent phosphorylation of JNK is involved in the activation of macrophages, we tested the hypothesis that myeloid MLK3 contributes to chronic ethanol-induced inflammatory responses in liver, leading to hepatocyte injury and cell death. Primary cultures of Kupffer cells, as well in vivo chronic ethanol feeding, were used to interrogate the role of MLK3 in the progression of liver injury. Phosphorylation of MLK3 was increased in primary cultures of Kupffer cells isolated from ethanol-fed rats compared to cells from pair-fed rats. Kupffer cells from ethanol-fed rats were more sensitive to LPS-stimulated cytokine production; this sensitization was normalized by pharmacological inhibition of MLK3. Chronic ethanol feeding to mice increased MLK3 phosphorylation robustly in F4/80⁺ Kupffer cells, as well as in isolated nonparenchymal cells. MLK3^−/− mice were protected from chronic ethanol-induced phosphorylation of MLK3 and JNK, as well as multiple indicators of liver injury, including increased ALT/AST, inflammatory cytokines, and induction of RIP3. However, ethanol-induced steatosis and hepatocyte apoptosis were not affected by MLK3. Finally, chimeric mice lacking MLK3 only in myeloid cells were also protected from chronic ethanol-induced phosphorylation of JNK, expression of inflammatory cytokines, and increased ALT/AST. MLK3 expression in myeloid cells contributes to phosphorylation of JNK, increased cytokine production, and hepatocyte injury in response to chronic ethanol. Our data suggest that myeloid MLK3 could be targeted for developing potential therapeutic strategies to suppress liver injury in ALD patients.Key words: Alcoholic liver disease (ALD), Kupffer cells, Necroptosis, Toll-like receptor 4 (TLR4), Cytokines     

Quantitative assessment of fibrosis and steatosis in liver biopsies from patients with chronic hepatitis C

BACKGROUNDS: Hepatic fibrosis is one of the main consequences of liver disease. Both fibrosis and steatosis may be seen in some patients with chronic hepatitis C and alcoholic liver disease (ALD). AIMS: To quantitate fibrosis and steatosis by stereological and morphometric techniques in patients with chronic hepatitis C and compare the results with a control group of patients with ALD. In addition, to correlate the quantitative features of fibrosis with the Ishak modified histological score. MATERIALS AND METHODS: Needle liver biopsies from 86 patients with chronic hepatitis C and from 32 patients with alcoholic liver disease (disease controls) were analysed by stereological and morphometric analyses using the Prodit 5.2 system. Haematoxylin and eosin and Picro-Mallory stained sections were used. The area fractions (A(A)) of fibrosis, steatosis, parenchyma, and other structures (bile duct and central vein areas) were assessed by stereological method. The mean diameters of fat globules were determined by morphometric analysis. RESULTS: Significant differences were found in the A(A) of fibrosis, including fibrosis within portal tract areas, between chronic hepatitis C patients and those with ALD (mean (SD): 19.14 (10.59) v 15.97 (12.51)). Portal and periportal (zone 1) fibrosis was significantly higher (p = 0.00004) in patients with chronic hepatitis C compared with the control group (mean (SD): 9.04 (6.37) v 3.59 (3.16)). Pericentral fibrosis (zone 3) occurred in both groups but was significantly more pronounced in patients with ALD. These results correlate well with the modified Ishak scoring system. However, in patients with cirrhosis (stage 6) with chronic hepatitis C the A(A) of fibrosis varied between 20% and 74%. The diameter of fat globules was significantly lower in patients with hepatitis C (p = 0.00002) than the ALD group (mean (SD): 14.44 (3.45) v 18.4 (3.32)). Microglobules were more frequent in patients with chronic hepatitis C than in patients with ALD. In patients with chronic hepatitis C, the fat globules had a zonal distribution in comparison with pan steatosis in ALD. CONCLUSION: Quantitative, stereological techniques are simple and reliable for evaluating hepatic fibrosis and steatosis in chronic hepatitis C. They are most useful for assessing the origin, location, and the stage of fibrosis. Stereology and morphometry are recommended for the quantitation of fibrosis and steatosis, particularly for the evaluation of new treatment strategies in patients with chronic hepatitis C.     

Increased severity of alcoholic liver injury in female verses male rats: a microarray analysis

Alcoholic liver disease (ALD) is an increasingly recognized condition that may progress to end-stage liver disease. In addition to alcohol consumption, genetic factors, dietary fatty acids, gender and viral infection potentiate the severity of alcoholic liver injury. In humans, significant gender differences in susceptibility to ALD are observed. In the intragastric infusion rat model of ALD, female rats developed more severe liver injury than males. To understand the effect of gender on the development of more severe ALD in female rats, we performed a microarray based expression profiling of genes in rats fed with fish oil and ethanol diet. A large number of genes showed significant changes in female livers compared to males. The upregulated genes in female liver were involved in proteosome endopeptidase activity, catalytic activity, lipid metabolism, alcohol metabolism, mitochondrial and oxidoreductase activity. The downregulated genes were involved in oxidoreductase activity, chaperone activity, and electron transport activity in the female liver as demonstrated by biological theme analysis. Ingenuity computational pathway analysis tools were used to identify specific regulatory networks of genes operative in promoting liver injury. These networks allowed us to identify a large cluster of genes involved in lipid metabolism, development, cellular growth and proliferation, apoptosis, carcinogenesis and various signaling pathways. Genes listed in this article that were significantly increased or decreased (expression two fold or more) were assigned to pathological functional groups and reviewed for relevance to establish hypotheses of potential mechanisms involved in ALD in female liver injury.     

Lactobacillus rhamnosus GG treatment potentiates intestinal hypoxia-inducible factor, promotes intestinal integrity and ameliorates alcohol-induced liver injury

Gut-derived endotoxin is a critical factor in the development and progression of alcoholic liver disease (ALD). Probiotics can treat alcohol-induced liver injury associated with gut leakiness and endotoxemia in animal models, as well as in human ALD; however, the mechanism or mechanisms of their beneficial action are not well defined. We hypothesized that alcohol impairs the adaptive response-induced hypoxia-inducible factor (HIF) and that probiotic supplementation could attenuate this impairment, restoring barrier function in a mouse model of ALD by increasing HIF-responsive proteins (eg, intestinal trefoil factor) and reversing established ALD. C57BJ/6N mice were fed the Lieber DeCarli diet containing 5% alcohol for 8 weeks. Animals received Lactobacillus rhamnosus GG (LGG) supplementation in the last 2 weeks. LGG supplementation significantly reduced alcohol-induced endotoxemia and hepatic steatosis and improved liver function. LGG restored alcohol-induced reduction of HIF-2α and intestinal trefoil factor levels. In vitro studies using the Caco-2 cell culture model showed that the addition of LGG supernatant prevented alcohol-induced epithelial monolayer barrier dysfunction. Furthermore, gene silencing of HIF-1α/2α abolished the LGG effects, indicating that the protective effect of LGG is HIF-dependent. The present study provides a mechanistic insight for utilization of probiotics for the treatment of ALD, and suggests a critical role for intestinal hypoxia and decreased trefoil factor in the development of ALD.     

Hepatic expression of CCL2 in alcoholic liver disease is associated with disease severity and neutrophil infiltrates

Serum levels and liver expression of CCL2 are increased in patients with alcoholic hepatitis (AH). In an experimental model of alcoholic liver disease (ALD), CCL2 was implicated in proinflammatory cytokines activation and hepatic lipid metabolism, but its role in human disease is currently unknown. In a large cohort of ALD patients, we analysed plasma levels and liver expression of CCL2 and their association with liver disease severity and histological lesions. We also studied the relationship between −2518 A > G CCL2 and CCR2 190 A/G polymorphisms and severity of ALD. We show that CCL2 plasma levels are increased in ALD patients compared with healthy subjects. AH patients had significantly higher plasma levels and hepatic expression of CCL2 than patients without AH. Plasma levels and hepatic expression of CCL2 were associated with disease severity. CCL2 liver expression was correlated with neutrophil infiltrate and interleukin (IL)-8 expression, but not with steatosis. Moreover, there were more G-allele carriers of −2518 A > G CCL2 polymorphism in severe AH patients than in other ALD patients. Our results demonstrate that CCL2 is increased in ALD, particularly in severe forms, and suggest a role for CCL2 in the pathogenesis of ALD via neutrophil recruitment.     

Platelet-derived growth factor isoform expression in carbon tetrachloride-induced chronic liver injury

Platelet-derived growth factor (PDGF) has an essential role in liver fibrogenesis, as PDGF-B and -D both act as potent mitogens on culture-activated hepatic stellate cells (HSCs). Induction of PDGF receptor type-beta (PDGFR beta) in HSC is well documented in single-dose carbon tetrachloride (CCl(4))-induced acute liver injury. Of the newly discovered isoforms PDGF-C and -D, only PDGF-D shows significant upregulation in bile duct ligation (BDL) models. We have now investigated the expression of PDGF isoforms and receptors in chronic liver injury in vivo after long-term CCl(4) treatment and demonstrated that isolated hepatocytes have the requisite PDGF signaling pathways, both in the naive state and when isolated from CCl(4)-treated rats. In vivo, PDGF gene expression showed upregulation of all PDGF isoforms and receptors, with values peaking at 4 weeks and decreasing to near basal levels by 8 and 12 weeks. Interestingly, PDGF-C increased significantly when compared to BDL-models. PDGF-A, PDGF-C and PDGF receptor type-alpha (PDGFR alpha) correlated closely with inflammation and steatosis. Immunohistochemistry revealed expression of PDGF-B, -C and -D in areas corresponding to centrilobular necrosis, inflammation and fibrosis, whereas PDGF-A localized in regenerative hepatocytes. PDGFR beta was identified along the fibrotic septa, whereas PDGFR alpha showed positive staining in fibrotic septa and regenerative hepatocytes. Despite a significant decline of PDGF isoforms, hepatocyte regeneration peaked at 8 weeks. A marked difference in the degree of fibrosis was observed amongst the individual animals. In summary, PDGF expression in liver damage primarily parallels mesenchymal cell proliferation and extracellular matrix production, rather than hepatocyte regeneration. We conclude that PDGF levels in chronic liver injury peak at 4 weeks after onset of injury, and that the outcome of chronic toxic liver injury strongly depends on the individual capacity for tissue regeneration in the weeks following the peak of PDGF expression.     

Synergism between ethanol and carbon tetrachloride in the generation of liver fibrosis

In this study, alcohol-induced histological lesions in a short-term experimental rat model were compared with those characteristic of human alcoholic liver disease. In the rat model used, pretreatment with carbon tetrachloride (CCl4) for 6 weeks was employed possibly to sensitize the liver for the effects of alcohol and shorten the time of induction of alcoholic liver disease. After 6 weeks of CCl4 treatment, subsequent maintenance on drinking water containing up to 10 per cent alcohol for 7 weeks potentiated liver fibroplasia as compared with non-alcohol-treated rats. However, steatosis and alcoholic hepatitis, as histological evidence for alcoholic liver disease as seen in humans, were not observed. In non-CCl4-pretreated control animals, alcohol administration had no effect on liver histology. It can be concluded that in the model used, CCl4 pretreatment sensitizes the liver to increase collagen deposition following alcohol administration, but not to steatosis or alcoholic hepatitis as seen in human alcoholic liver disease. In this experimental set-up, direct metabolic interaction of CCl4 with alcohol as a cause of the increased fibroplasia can be excluded.     

TUNEL-positive hepatocytes in alcoholic liver disease

 Alcohol-induced damage to the liver results in a wide array of typical alterations. Whereas the mechanisms involved in the pathogenesis of fatty change, hepatocyte ballooning, Mallory body formation and fibrosis have been studied in detail, little is known about hepatocyte apoptosis in alcoholic liver disease (ALD). In this retrospective study we analysed parenchymal cell death in ALD systematically by the use of in situ DNA nick-end labelling (ISEL/TUNEL). We show that increased hepatocyte TdT labelling occurs in ALD. Labelling is observed more frequently in parenchymal areas exhibiting advanced damage (ballooning degeneration with or without Mallory bodies, cholestasis and perisinusoidal fibrosis). In addition, hepatocyte TdT labelling is higher where there is septal fibrosis and nodular remodelling. Conversely, it is not elevated in ballooning hepatocytes themselves, but rather in the apparently normal hepatocytes in their vicinity. Received: 29 July 1996 / Accepted: 18 March 1997     

Adaptive growth changes in the liver remnant are affected by the size of hepatectomy in rats

In this study we investigated the dynamics of hepatocyte hyperplasia and hypertrophy in rats subjected to increasing sizes of partial hepatectomy (PH). A total of 104 rats were randomized according to the size of PH. On postoperative days (PODs) 1, 3 and 5, blood was drawn and the remnant liver removed for stereological analysis. Liver parameters and regeneration rate were significantly affected by size of PH. On POD 1, hepatocyte volumes had increased significantly in all PH groups. On POD 3, all groups showed hepatocyte volumes approximating baseline. On POD 5, hepatocyte volumes were significantly lower in PH (90) than in baseline, sham and PH (30) rats. Increasing hepatocyte proliferation was not observed following PH (30). Following PH (70), cell proliferation was significantly elevated on PODs 1 and 3, and following PH (90) on PODs 3 and 5. In conclusion, general hypertrophy of hepatocytes after different size of PH was followed by hepatocyte proliferation only in the liver remnant of PH (70) and PH (90).     

Oxidative stress and oval cell accumulation in mice and humans with alcoholic and nonalcoholic fatty liver disease

In animals, the combination of oxidative liver damage and inhibited hepatocyte proliferation increases the numbers of hepatic progenitors (oval cells). We studied different murine models of fatty liver disease and patients with nonalcoholic fatty liver disease or alcoholic liver disease to determine whether oval cells increase in fatty livers and to clarify the mechanisms for this response. To varying degrees, all mouse models exhibit excessive hepatic mitochondrial production of H(2)O(2), a known inducer of cell-cycle inhibitors. In mice with the greatest H(2)O(2) production, mature hepatocyte proliferation is inhibited most, and the greatest number of oval cells accumulates. These cells differentiate into intermediate hepatocyte-like cells after a regenerative challenge. Hepatic oval cells are also increased significantly in patients with nonalcoholic fatty liver disease and alcoholic liver disease. In humans, fibrosis stage and oval cell numbers, as well as the number of intermediate hepatocyte-like cells, are strongly correlated. However, cirrhosis is not required for oval cell accumulation in either species. Rather, as in mice, progenitor cell activation in human fatty liver diseases is associated with inhibited replication of mature hepatocytes. The activation of progenitor cells during fatty liver disease may increase the risk for hepatocellular cancer, similar to that observed in the Solt-Farber model of hepatocarcinogenesis in rats.     

Dynamics of hepatocyte proliferation in regenerating fetal rat liver

We studied hepatocyte proliferation in the regenerating liver of 17-day fetuses of outbred albino rats. The animals were sacrificed every 3 h over 2 days after resection of 20% liver. The number of mitoses beyond the zone of injury increased sharply 12 and 24 h after resection. The hepatocyte mitotic index in the perifocal zone did not surpass the mitotic index in regions distant from the focus of injury during any of the studied periods. No circadian rhythm of hepatocyte mitotic activity was detected for resected or intact fetal liver. The injury caused virtually no changes in hepatocyte mitosis phase ratio in the operated compared to intact liver, which attested to stable course of mitosis. The weight of fetal liver recovered at the expense of enhanced mitotic activity of hepatocytes in the entire liver.     

腺苷酸激活蛋白激酶在大鼠酒精性肝病中的表达减少

 【摘要】：目的：观察酒精对大鼠肝脏腺苷酸活化蛋白激酶（AMPK）表达水平的影响。方法：雄性Wistar大鼠50只,随机分出10只为正常对照组,其余动物采用酒精灌胃的方法,随机分为模型4、8、12、16周组,留取血清及肝组织标本;检测血清ALT、AST、CHE、TG、TC、LDL、VLD、HDL等生化指标,应用HE、天狼红及苏丹Ⅳ染色观察肝组织病理变化;应用免疫组织化学染色、RT-PCR法检测AMPK、ACC、SREBP蛋白及mRNA的表达。结果：随着酒精造模时间延长,血清ALT和AST水平逐渐升高,CHE水平逐渐降低;血清TG、TC、LDL水平逐渐升高,HDL水平逐渐降低;肝组织中AMPK表达逐渐减少,ACC及SREBP表达逐渐增多;肝组织AMPK与ACC及SREBP的表达呈负相关(r=-0.911, P<0.01; r=-0.907, P<0.01)。结论：ALD发病过程中AMPK表达减少,对ACC、SREBP活化的抑制作用减弱,脂质合成增多,造成脂肪堆积于肝脏中,是造成肝脏损伤的重要因素。AMPK作为一个新的药物靶点,为ALD的防治提供了新的思路。     

The effect of carbon tetrachloride on the copper-laden rat liver

Copper is believed to be hepatotoxic in Indian Childhood Cirrhosis and Wilson's disease. However, copper-loading causes only minimal hepatic damage in animal models. The hypothesis was therefore proposed that a second hepatic insult may precipitate or perpetuate liver injury in a copper-laden liver. In non-copper-dosed rats CCl4 (10 mmol/kg, i.p.) produced elevated serum AST (809 +/- 298 IU/l, normal 20 +/- 5) and ALT (295 +/- 157 IU/l, normal 6 +/- 1) and extensive liver cell necrosis, portal tract inflammation, fat deposition, and perilobular hepatocyte ballooning. In rats whose liver copper was elevated from 75 +/- 13 to 461 +/- 13 micrograms/g by oral copper supplementation, CCl4 produced much smaller increases in AST (492 +/- 80 IU/l) and ALT (172 +/- 57 IU/l) and mild focal liver cell necrosis. Fat deposition and perilobular vacuolation were not reduced. Prior copper-loading of rats unequivocally protected against the CCl4-induced liver injury. Triglyceride accumulation, however, was apparently unaffected. The possible interactions of copper with prostaglandin-mediated inflammation and with free-radical-induced liver damage are discussed.     

Increased methylation demand exacerbates ethanol-induced liver injury

We previously reported that chronic ethanol intake lowers hepatocellular S-adenosylmethionine to S-adenosylhomocysteine ratio and significantly impairs many liver methylation reactions. One such reaction, catalyzed by guanidinoacetate methyltransferase (GAMT), is a major consumer of methyl groups and utilizes as much as 40% of the SAM-derived groups to convert guanidinoacetate (GAA) to creatine. The exposure to methyl-group consuming compounds has substantially increased over the past decade that puts additional stresses on the cellular methylation potential. The purpose of our study was to investigate whether increased ingestion of a methyl-group consumer (GAA) either alone or combined with ethanol intake, plays a role in the pathogenesis of liver injury. Adult male Wistar rats were pair-fed the Lieber DeCarli control or ethanol diet in the presence or absence of GAA for 2 weeks. At the end of the feeding regimen, biochemical and histological analyses were conducted. We observed that 2 weeks of GAA- or ethanol-alone treatment increases hepatic triglyceride accumulation by 4.5 and 7-fold, respectively as compared with the pair-fed controls. However, supplementing GAA in the ethanol diet produced panlobular macro- and micro-vesicular steatosis, a marked decrease in the methylation potential and a 28-fold increased triglyceride accumulation. These GAA-supplemented ethanol diet-fed rats displayed inflammatory changes and significantly increased liver toxicity compared to the other groups. In conclusion, increased methylation demand superimposed on chronic ethanol consumption causes more pronounced liver injury. Thus, alcoholic patients should be cautioned for increased dietary intake of methyl-group consuming compounds even for a short period of time.     

The epidemiology, pathogenesis and histopathology of fatty liver disease

Fatty liver disease includes non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD), each of which is increasing in prevalence. Each represents a histological spectrum that extends from isolated steatosis to steatohepatitis and cirrhosis. NAFLD is associated with obesity, diabetes, and insulin resistance, and is considered to be the liver manifestation of the metabolic syndrome. The pathogenesis of NAFLD and ALD involves cytokines, adipokines, oxidative stress, and apoptosis. Histopathology is the gold standard for assessing the severity of liver damage in NAFLD and ALD. We have reviewed the literature, and described and compared the epidemiology, natural disease history, pathogenesis and histopathology of NAFLD and ALD.     

PGE2 alleviates kidney and liver damage, decreases plasma renin activity and acute phase response in cirrhotic rats with acute liver damage.

In this study, we evaluated the effect of prostaglandin E2 (PGE2) on renal and hepatic function using an experimental cirrhosis model plus acute liver damage (ALD). Male Wistar rats treated with carbon tetrachloride (CCl4) for 8 weeks were used for the cirrhosis model. Cirrhotic rats were further exposed to an additional acute dose of CCl4 to induce ALD and then treated with PGE2 intramuscularly twice a day for 7 days (200 microg/Kg/day). PGE2 administration started 3 h after the additional dosing of CCl4 and PGE2 effect on hepatorenal function was examined on days 1, 2, 3, and 7. PGE2-treatment ameliorated the decrease in urinary sodium excretion, and normalized serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and plasma renin observed in cirrhotic rats with ALD. In addition, PGE2-treatment decreased mean arterial pressure, glomerular hypercellularity and thickening of the kidney capillary wall, and liver steatosis and cellular necrosis. Also, PGE2 increased the number of regenerative nodules. Finally, PGE2-treatment inhibited the increase in Alpha 1-acid glycoprotein (pAGP), fibrinogen, and Apo A-1 mRNA expression by 83%, 59%, and 77%, respectively. These results suggest that PGE2 administration may decrease the expression of acute phase proteins. In conclusion, PGE2-treatment improved hepatic and renal function and may be useful to down-regulate the acute phase response in cirrhotic rats presenting ALD induced by CCl4.     

Severity of liver injury in experimental alcoholic liver disease. Correlation with plasma endotoxin, prostaglandin E2, leukotriene B4, and thromboxane B2.

The purpose of our study is to determine if a relationship exists between the severity of injury in experimental alcoholic liver disease and plasma levels of endotoxin, prostaglandin E2, leukotriene B4, and thromboxane B2. Four groups of animals (n = 4 to 8 in each group) were fed a liquid diet with corn oil (25% of calories) and ethanol over various time periods: 1 week, 2 weeks, 1 month, and 2 months. At sacrifice, liver pathology scores and plasma levels of the above were determined. Plasma levels of endotoxin were already increased after 1 week (26.6 +/- 18.6 pg/ml) and continued to increase over time, with the highest levels at 2 months (69.5 +/- 24.5 pg/ml). A strong positive correlation (r = 0.84, P < 0.001) was seen between plasma endotoxin levels and severity of liver injury. The pathology score also correlated positively with leukotriene B4 (r = 0.47, P < 0.05) and thromboxane B2 (0.66, P < 0.01). A negative correlation was obtained with prostaglandin E2 levels (r = -0.44, P < 0.05). A positive correlation was also seen between endotoxin levels and leukotriene B4 (r = 0.57, P < 0.02) and thromboxane B2 (0.64, P < 0.01); a negative correlation was obtained with prostaglandin E2 levels (r = -0.55, P < 0.02). Each metabolite was also correlated with each of the features of alcoholic liver injury, i.e., fatty liver, necrosis, and inflammation. With prostaglandin E2, the most marked decrease was seen in association with severe fatty liver (3 to 4+). Thromboxane B2 correlated best with presence of inflammation and necrosis. Our study shows the importance of endotoxin in the pathogenesis of experimental alcoholic liver disease and suggests that endotoxin modulates production of eicosanoids that contribute to the severity of liver injury.