Maltose Dextrin Research Articles

The effects of chronic alcohol self-administration in nonhuman primate brain networks.

Long-term alcohol abuse is associated with change in behavior, brain structure, and brain function. However, the nature of these changes is not well understood. In this study, we used network science to analyze a nonhuman primate model of ethanol self-administration to evaluate functional differences between animals with chronic alcohol use and animals with no exposure to alcohol. Of particular interest was how chronic alcohol exposure may affect the resting state network. Baseline resting state functional magnetic resonance imaging was acquired in a cohort of vervet monkeys. Animals underwent an induction period where they were exposed to an isocaloric maltose dextrin solution (control) or ethanol in escalating doses over three 30-day epochs. Following induction, animals were given ad libitum access to water and a maltose dextrin solution (control) or water and ethanol for 22h/d over 12months. Cross-sectional analyses examined region of interests in hubs and community structure across animals to determine differences between drinking and nondrinking animals after the 12-month free access period. Animals were classified as lighter (<2.0g/kg/d) or heavier drinkers (≥2.0g/kg/d) based on a median split of their intake pattern during the 12-month ethanol free access period. Statistical analysis of hub connectivity showed significant differences in heavier drinkers for hubs in the precuneus, posterior parietal cortices, superior temporal gyrus, subgenual cingulate, and sensorimotor cortex. Heavier drinkers were also shown to have less consistent communities across the brain compared to lighter drinkers. The different level of consumption between the lighter and heavier drinking monkeys suggests that differences in connectivity may be intake dependent. Animals that consume alcohol show topological differences in brain network organization, particularly in animals that drink heavily. Differences in the resting state network were linked to areas that are associated with spatial association, working memory, and visuomotor processing.

UPLC/Q-TOFMS-Based Metabolomics Studies on the Protective Effect of Panax notoginseng Saponins on Alcoholic Liver Injury.

Consistent, excessive alcohol consumption leads to liver injury. The aim of the present study is to evaluate the possible efficacy of Panax notoginseng saponins (PNS) against chronic alcohol-induced liver injury using LC-MS-based urinary metabolomics. Mice were fed a Lieber-DeCarli liquid diet containing alcohol or isocaloric maltose dextrin as a control diet with or without PNS (200 mg/kg/BW) for 4 weeks. Treatment with PNS significantly reduced the increases in plasma ALT and AST levels, hepatic levels of reactive oxygen species (ROS) and malondialdehyde (MDA), which induced by chronic alcohol exposure. Conversely, PNS was also found to restore the glutathione (GSH) depletion and increase the superoxide dismutase (SOD) activities. The end-point urine sample of each mouse was collected overnight (24 h) in metabolic cages and their metabolic profiling changes were analyzed using UPLC/Q-TOFMS followed by multivariate statistical analysis. After 4 week of Lieber-DeCarli alcohol diet feeding, the metabolic profile experienced great perturbation in PCA score plot, and the treatment of PNS could assist to regulate the disturbed metabolic profile induced by alcohol exposure. Additionally, sixteen potential biomarkers responsible for derivations of the metabolic profile induced by alcohol exposure were identified, and the alcohol-induced changes in these biomarkers, except hexanoylglycine, could be partially or nearly reversed by PNS treatment. Taken together, PNS protects against chronic alcohol-induced liver injury. Our findings demonstrated that the LC-MS-based metabolomics approach is a useful tool to investigate the efficacy of Chinese medicines.

Protective effects of Penthorum chinense Pursh against chronic ethanol-induced liver injury in mice

Ethnopharmacological relevancePenthorum chinense Pursh (Penthoraceae) has been used as a Miao ethnomedicine for the treatment of jaundice, cholecystitis, edema, infectious hepatitis and anti-drunk hangover in China. The aim of present study is to investigate the possible protective effects of Penthorum chinense against chronic ethanol-induced liver injury. Material and methodsMice were fed a Lieber-DeCarli liquid diet containing alcohol or isocaloric maltose dextrin as control diet with or without aqueous extract of Penthorum chinense (PCP, 5.15 and 10.30g/kg/BW) for 4 weeks. Silymarin (86mg/kg) was used as positive control to compare the efficacy of PCP against chronic ethanol-induced hepatotoxicity. ResultsTreatment with PCP (10.30g/kg) significantly reduced the increases in serum ALT and AST levels, hepatic lipid accumulation and inflammatory cytokines (i.e. TNF-α, IL-6), which were induced by chronic ethanol exposure. PCP was also found to attenuate reactive oxygen species (ROS) generation and malondialdehyde (MDA) level, restore the glutathione (GSH) depletion, and increase the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. In addition, PCP supplementation (10.30g/kg) inhibited the induction of hepatic cytochrome P450 2E1 (CYP2E1), a major contributor to ethanol-mediated oxidative stress, and up-regulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream anti-oxidant protein heme oxygenase-1 (HO-1) in ethanol-treated mice. ConclusionsThese results indicate that the co-treatment with aqueous extract of Penthorum chinense (10.30g/kg) protects against chronic ethanol-induced liver injury, possibly through suppressing CYP2E1-mediated oxidative stress and enhancing the oxidant defense systems via the activation of Nrf2/HO-1 pathway.

Embryo transfers between C57BL/6J and DBA/2J mice: Examination of a maternal effect on ethanol teratogenesis.

Genetic factors influence fetal alcohol spectrum disorders (FASDs) in both humans and animals. Experiments using inbred and selectively bred mouse stocks that controlled for (1) ethanol dose, (2) maternal and fetal blood ethanol levels, and (3) fetal developmental exposure stage, show genotype can affect teratogenic outcome. Other experiments distinguish the teratogenic effects mediated by maternal genotype from those mediated by fetal genotype. One technique to distinguish maternal versus fetal genotype effect is to utilize embryo transfers. This study is the first to examine ethanol teratogenesis – fetal weight deficits and mortality, and digit, kidney, and vertebral malformations – in C57BL/6J (B6) and DBA/2J (D2) fetuses that were transferred as blastocysts into B6 and D2 dams. We hypothesized that, following maternal alcohol exposure, B6 and D2 fetuses gestating within B6 mothers, as compared to D2 mothers, will exhibit a higher frequency of malformations. On day 9 of pregnancy, females were intubated (IG) with either 5.8 g/kg ethanol (E) or maltose-dextrin (MD). Other females were mated within strain and treated with either ethanol or maltose, or were not exposed to either treatment. Implantation rates were affected by genotype. Results show more B6 embryos implanted into D2 females than B6 females (p < 0.05; 47% vs. 23%, respectively). There was no difference in the percentage of D2 embryos implanting into B6 and D2 females (14 and 16%, respectfully). Litter mortality averaged 24% across all experimental groups. Overall, in utero ethanol exposure reduced mean litter weight compared to maltose treatment (E = 1.01 g; MD = 1.19 g; p < 0.05); but maltose exposed litters with transferred embryos weighed more than similarly treated natural litters (1.30 g vs. 1.11 g; p < 0.05). Approximately 50% of all ethanol exposed B6 fetuses exhibited some malformation (digit, vertebral, and/or kidney) regardless of whether they were transferred into a B6 or D2 female, or were naturally conceived. This suggests the D2 maternal uterine environment did not offer any protection against ethanol teratogenesis for B6 fetuses. One of the questions remaining is the how the B6 uterine environment affects D2 teratogenesis. No definitive conclusions can be drawn because too few viable D2 litters were produced.

Enhanced AMPK phosphorylation contributes to the beneficial effects of Lactobacillus rhamnosus GG supernatant on chronic-alcohol-induced fatty liver disease

BackgroundWe have previously demonstrated that Lactobacillus rhamnosus GG culture supernatant (LGGs) prevents acute-alcohol-exposure-induced hepatic steatosis and injury. The protective effects of LGGs were attributed to the improved intestinal barrier function leading to decreased endotoxemia. The purpose of this study was to determine whether LGGs was effective in protecting against chronic-alcohol-induced hepatic steatosis and injury and to evaluate the underlying mechanisms of LGGs on hepatic lipid metabolism. MethodsC57BL/6N mice were fed liquid diet containing 5% alcohol or pair-fed isocaloric maltose dextrin for 4 weeks. LGGs at a dose equivalent to 109 CFU/day/mouse was given in the liquid diet. Hepatic steatosis, liver enzymes and hepatic apoptosis were analyzed. ResultsLGGs prevented alcohol-mediated increase in hepatic expression of lipogenic genes, sterol regulatory element binding protein-1 and stearoyl-CoA desaturase-1 and increased the expression of peroxisome proliferator activated receptor-α, peroxisome proliferator-activated receptor gamma coactivator protein-1α and carnitine palmitoyltransferase-1, leading to increased fatty acid β-oxidation. Importantly, chronic alcohol exposure decreased adenosine-monophosphate-activated protein kinase (AMPK) phosphorylation and increased acetyl-CoA carboxylase activity, which were attenuated by LGGs administration. LGGs also decreased Bax expression and increased Bcl-2 expression, which attenuated alcohol-induced hepatic apoptosis. These LGGs-regulated molecular changes resulted in the attenuation of chronic-alcohol-exposure-mediated increase in hepatic fat accumulation and liver injury. ConclusionsProbiotic LGG culture supernatant is effective in the prevention of chronic-alcohol-exposure-induced hepatic steatosis and injury. LGGs likely exerts its beneficial effects, at least in part, through modulation of hepatic AMPK activation and Bax/Bcl-2-mediated apoptosis.

Chronic alcohol administration causes expression of calprotectin and RAGE altering the distribution of zinc ions in mouse testis

Several studies reported that chronic alcohol consumption alters the intestinal mucosa barrier, and subsequent entrance of endotoxins into the bloodstream. In many tissues endotoxin exposure causes the expression of calprotectin (CP) and the receptor for advanced glycation -end products (RAGE). In this study we investigated whether chronic alcohol administration causes expression of CP and RAGE in mouse testis. The distribution of free and loosely bound Zn2+ (FLB-Zn2+) in the testicular tissues was also evaluated. Alcohol-induced testicular damage was documented by measuring testosterone blood levels and by light and electron microscope studies. Twenty mice were treated daily for three weeks with 3.0 g/kg of a 25% solution of alcohol. Ten mice were treated in the same period of time with a solution of maltose dextrins, isocaloric to alcohol. Twenty untreated mice were used as controls. Alcohol treated mice showed diffuse expression of CP and RAGE in the interstitial cells. RAGE was found also in the basal compartment of the seminiferous tubules. Depletion of FLB-Zn2+ was observed in the adluminal compartment of the seminiferous tubules. Expression of CP and RAGE was not found in control mice and maltose dextrin treated mice. Our results indicated novel mechanisms by which alcohol acts in testis. Indeed, CP and RAGE may cause the generation of oxidants and inflammatory mediators, with negative impact on testicular functions. Depletion of FLB-Zn2+ may contribute to the dysregulation of spermatogenesis.

Build a better mouse model, and the world will beat a path to your door

Build a better mouse model, and the world will beat a path to your door

Effects of fetal alcohol exposure on zinc homeostasis in the newborn pulmonary alveolar macrophage

Since zinc is essential for innate and adaptive immunity, zinc deficiency increases susceptibility to infection and magnifies existing infections. To examine the effects of in utero alcohol exposure, C57BL/6 female mice were fed the Lieber DeCarli liquid diet with 25% ethanol derived calories or with 25% maltose dextrin derived calories during preconception and pregnancy. At delivery, alveolar macrophages (AMs) from dams and pups were isolated and treated with FluoZin‐3AM to measure AM zinc and FITC‐labeled inactive Staph. aureus to measure phagocytosis. AMs from pregnant ethanol‐fed dams had lower intracellular zinc (p=0.007) and decreased phagocytic function (p&lt;0.05), when compared to pregnant controls. AMs isolated from pups with fetal ethanol exposure displayed lower zinc levels (p=0.078) and AM function (p=0.041) than unexposed pups. Additionally, protein expression of the zinc transporter, ZnT1, was significantly lower in exposed pups than unexposed pups (p=0.003). Chronic alcohol exposure in adults or chronic in utero exposure decreases pulmonary AM function via decreased zinc availability which may contribute to an increased risk of respiratory infections.Funding: NIH/NIAAA P50 AA135757(LAB)

Fibroblast growth factor 21 is required for alcohol‐induced adipose tissue lipoatrophy in mice

Fibroblast growth factor 21 (FGF‐21) is a member of FGF superfamily and has been identified as a potent metabolic regulator. Studies have shown that FGF‐21 plays a critical role in adipose tissue lipolysis. FGF‐21 KO mice and controls (C57BL/6 mice) were fed Lieber deCarli liquid diet containing 5% alcohol or pair‐fed with isocaloric maltose dextrin for 12 days. Six hours before sacrificing, a binge dose of alcohol at 6g/kg body weight was given to the mice by gavage. Alcohol significantly increased serum and hepatic FGF‐21 in wild type mice. Alcohol decreased white adipose tissue mass in wild type mice, but not in FGF‐21 KO mice, indicating a requirement of FGF‐21 for alcohol‐induced adipose tissue lipoatrophy. A mechanism underlying adipose tissue lipolysis is the cAMP‐mediated hormone sensitive lipase (HSL) pathway, which is regulated by catecholamines, nicotinic acid, and insulin. Perilipin (PLIN) is a coating protein for lipid droplet and protects lipids waiting to be degraded. Alcohol increased phosphorylation of PLIN and HSL in wild type mice, which may be responsible for the observed adipose lipolysis by alcohol. Alcohol did not affect PLIN and HSL phosphorylation in FGF‐21 knockout mice. Our results suggest that FGF‐21 is a potential regulator of alcohol‐induced white adipose tissue hyperlipolysis via HSL/PLIN pathway, which may contribute to alcoholic fatty liver formation.

Deletion of angiotensin II type 1 receptor gene or scavenge of superoxide prevents chronic alcohol‐induced aortic damage and remodelling

To investigate whether chronic alcohol consumption induces vascular injury via angiotensin II (Ang II) type 1 (AT1) receptor-dependent superoxide generation, male transgenic mice with knockout of AT1 gene (AT1-KO) and age-matched wild-type (WT) C57BL/6 mice were pair-fed a modified Lieber-DeCarli alcohol or isocaloric maltose dextrin control liquid diet for 2 months. Ethanol content (%, W/V) in the diet was 4.8 (34% of total calories) at initiation, and gradually increased up to 5.4 (38% of total calories). For some WT mice with and without alcohol treatment, superoxide dismutase mimetic (MnTMPyP) was given simultaneously by intraperitoneal injection at 5 mg/kg body weight daily for 2 months. At the end of studies, aortas were harvested for histopathological and immunohistochemical examination. Significant increases in the wall thickness and structural disarrangement of aorta were found in alcohol group, along with significant increases in aortic oxidative and/or nitrosative damage, expressions of NADPH oxidases (NOXs), inflammatory response, cell death and proliferation, and remodelling (fibrosis). However, these pathological changes were completely attenuated in alcohol-treated AT1-KO mice or in alcohol-treated WT mice that were also simultaneously treated with MnTMPyP for 2 months. These results suggest that chronic alcohol consumption may activate NOX via Ang II/AT1 receptor, to generate superoxide and associated peroxynitrite that in turn causes aortic nitrosative damage, inflammation, cell death and proliferation, and remodelling. Therefore, blocking Ang II/AT1 system or scavenging superoxide may become a potential preventive and/therapeutic approach to alcoholic vascular damage.

Deletion of Angiotensin II Type 1 Receptor Gene Attenuates Chronic Alcohol-Induced Retinal Ganglion Cell Death With Preservation of VEGF Expression

Purpose: To investigate how chronic alcohol consumption affects adult visual nervous system and whether renin-angiotensin system (RAS) is involved in this pathogenic process.Methods: Male transgenic mice with angiotensin II (Ang II) type 1 (AT1) receptor gene knockout (AT1-KO) and age-matched wild-type (WT) mice were pair-fed a modified Lieber-DeCarli alcohol or isocaloric maltose dextrin control liquid diet for 2 months. At the end of the study, retinas were harvested and subjected to histopathological and immunohistochemical examination.Results: We found that chronic alcohol consumption significantly increased retinal ganglion cell (RGC) apoptosis in the retina of WT mice, but not AT1-KO mice, detected by terminal deoxynucleotidyl-transferase-mediated dUTP-nick-end labeling staining and caspase 3 activation, along with an up-regulation of AT1 expression in RGC. At the same time, the phosphorylation of P53 in RGCs was significantly increased for both WT and AT1-KO mice exposed to alcohol, which could be significantly, although partially, prevented by AT1 gene deletion. We further examined the expression of vascular endothelial growth factor (VEGF) and CD31, and found that alcohol treatment significantly decreased the expression of VEGF and CD31 in RGCs of WT mice, but not AT1-KO mice.Conclusion: Taken together, our study demonstrates that the induction of RGC apoptosis by chronic alcohol exposure may be related to p53-activation and VEGF depression, all which are partially dependent of AT1 receptor activation.

Gene Expression Changes in C57BL/6J and DBA/2J Mice Following Prenatal Alcohol Exposure

Prenatal alcohol exposure can result in fetal alcohol spectrum disorders (FASD). Not all women who consume alcohol during pregnancy have children with FASD and studies have shown that genetic factors can play a role in ethanol teratogenesis. We examined gene expression in embryos and placentae from C57BL/6J (B6) and DBA/2J (D2) mice following prenatal alcohol exposure. B6 fetuses are susceptible to morphological malformations following prenatal alcohol exposure while D2 are relatively resistant. Male and female B6 and D2 mice were mated for 2 hours in the morning, producing 4 embryonic genotypes: true-bred B6B6 and D2D2, and reciprocal B6D2 and D2B6. On gestational day 9, dams were intubated with 5.8 g/kg ethanol, an isocaloric amount of maltose dextrin, or nothing. Four hours later, dams were sacrificed and embryos and placentae were harvested. RNA was extracted, labeled and hybridized to Affymetrix Mouse Genome 430 v2 microarray chips. Data were normalized, subjected to analysis of variance and tested for enrichment of gene ontology molecular function and biological process using the Database for Annotation, Visualization and Integrated Discovery (DAVID). Several gene classes were differentially expressed in B6 and D2 regardless of treatment, including genes involved in polysaccharide binding and mitosis. Prenatal alcohol exposure altered expression of a subset of genes, including genes involved in methylation, chromatin remodeling, protein synthesis, and mRNA splicing. Very few genes were differentially expressed between maltose-exposed tissues and tissues that received nothing, so we combined these groups for comparisons with ethanol. While we observed many expression changes specific to B6 following prenatal alcohol exposure, none were specific for D2. Gene classes up- or down-regulated in B6 following prenatal alcohol exposure included genes involved in mRNA splicing, transcription, and translation. Our study identified several classes of genes with altered expression following prenatal alcohol exposure, including many specific for B6, a strain susceptible to ethanol teratogenesis. Lack of strain specific effects in D2 suggests there are few gene expression changes that confer resistance. Future studies will begin to analyze functional significance of the expression changes.

Discontinuous and heterogeneous glass transition behavior of carbohydrate polymer–plasticizer systems

In order to understand the glass transition properties of carbohydrate polymer–plasticizer systems, glass transition temperatures of dextrin–glucose and dextrin–maltose systems were investigated systematically using differential scanning calorimetry. The onset (Tgon) and offset (Tgoff) of the glass transition decreased with increasing plasticizer (glucose or maltose) content, and showed an abrupt depression at certain plasticizer content. The abrupt depression of Tgoff occurred at higher plasticizer content than that of Tgon. The glass transition was much broader for intermediate plasticizer content. From the enthalpy relaxation behavior of samples aged at various temperatures, it was found that two different glass transitions occurred contentiously in the broad glass transition. These results suggested that carbohydrate polymer–plasticizer systems can be classified into three regions: the entrapment of the plasticizer by the polymer, the formations of the polymer–plasticizer and plasticizer-rich domains, and the embedment of polymer into the plasticizer.

PI3K/Akt pathway activation was involved in acute ethanol-induced fatty liver in mice

Accumulating evidences support the important roles of sterol regulatory element-binding protein-1 (SREBP-1) activation in ethanol-induced fatty liver, but the underlying mechanisms for its activation are not fully understood. Recent studies have demonstrated that phosphatidylinositol 3 kinase (PI3K)/Akt pathway activation could enhance SREBP-1 activity. The current study was designed to investigate the potential roles of PI3K/Akt pathway in acute ethanol-induced fatty liver in mice. In the first experiment, mice were treated with ethanol (2.5 or 5g/kg bw) or isocaloric/isovolumetric maltose–dextrin solution, and sacrificed at several time points after ethanol exposure. As expected, ethanol dose-dependently increased the hepatic triglyceride (TG) levels and the protein levels of the mature form of SREBP-1 (n-SREBP-1). The phosphorylation of Akt and glycogen synthase kinase-3β (GSK-3β) was significantly increased in mice treated with ethanol (5g/kg bw), while the protein levels of PI3K-p85 were significantly reduced. To confirm the roles of PI3K/Akt pathway, mice were then pretreated with wortmannin (0.7 or 1.4mg/kg bw), a specific PI3K/Akt pathway inhibitor, before exposure to ethanol. Interestingly, a dual effect of wortmannin was observed. Low dose of wortmannin significantly reduced the hepatic TG levels, while high dose of wortmannin aggravated ethanol-induced fatty liver. The ratio of LC3II/LC3I of wortmannin (1.4mg/kg bw) group mice was significantly increased, while the p62 protein level was significantly decreased compared to those of ethanol group, which indicated that wortmannin (1.4mg/kg bw) might suppress the lipid degradation by autophagy. These results supported the hypothesis that PI3K/Akt activation might be involved in acute ethanol-induced fatty liver, and PI3K/Akt inhibitors might have therapeutic potential for the treatment of ethanol-induced fatty liver.

Disruptions in serotonergic regulation of cortical glutamate release in primate insular cortex in response to chronic ethanol and nursery rearing

Early-life stress has been shown to increase susceptibility to anxiety and substance abuse. Disrupted activity within the anterior insular cortex (AIC) has been shown to play a role in both of these disorders. Altered serotonergic processing is implicated in controlling the activity levels of the associated cognitive networks. We therefore investigated changes in both serotonin receptor expression and glutamatergic synaptic activity in the AIC of alcohol-drinking rhesus monkeys. We studied tissues from male rhesus monkeys raised under two conditions: Male rhesus monkeys (1) “mother reared” (MR) by adult females (n=9) or (2) “Nursery reared” (NR), that is, separated from their mothers and reared as a separate group under surrogate/peer-reared conditions (n=9). The NR condition represents a long-standing and well-validated nonhuman primate model of early life stress. All monkeys were trained to self-administer ethanol (4% w/v) or an isocaloric maltose–dextrin control solution. Subsets from each rearing condition were then given daily access to ethanol, water, or maltose–dextrin for 12 months. Tissues were collected at necropsy and were further analyzed. Using real time RT-PCR we found that ethanol-naive, NR monkeys had lower AIC levels of 5-HT1A and 5-HT2A receptor mRNA compared with ethanol-naive, MR animals. Although NR monkeys consumed more ethanol over the 12-month period compared with MR animals, both MR and NR animals expressed greater 5-HT1A and 5-HT2A receptor mRNA levels following chronic alcohol self-administration. The interaction between nursery-rearing conditions and alcohol consumption resulted in a significant enhancement of both 5-HT1A and 5-HT2A receptor mRNA levels such that lower expression levels observed in nursery-rearing conditions were not found in the alcohol self-administration group. Using voltage clamp recordings in the whole cell configuration we recorded excitatory postsynaptic currents in both ethanol-naive and chronic self-administration groups of NR and MR monkeys. Both groups that self-administered ethanol showed greater glutamatergic activity within the AIC. This AIC hyperactivity in MR alcohol-consuming monkeys was accompanied by an increased sensitivity to regulation by presynaptic 5-HT1A receptors that was not apparent in the ethanol-naive, MR group. Our data indicate that chronic alcohol consumption leads to greater AIC activity and may indicate a compensatory upregulation of presynaptic 5-HT1A receptors. Our results also indicate that AIC activity may be less effectively regulated by 5-HT in ethanol-naive NR animals than in NR monkeys in response to chronic ethanol self-administration. These data suggest possible mechanisms for increased alcohol seeking and possible addiction potential among young adults who had previously experienced early-life stress that include disruptions in both AIC activity and serotonin system dynamics.

Activation of peroxisome proliferator-activated receptor-γ by rosiglitazone improves lipid homeostasis at the adipose tissue-liver axis in ethanol-fed mice.

The development of alcohol-induced fatty liver is associated with a reduction of white adipose tissue (WAT). Peroxisome proliferator-activated receptor (PPAR)-γ prominently distributes in the WAT and plays a crucial role in maintaining adiposity. The present study investigated the effects of PPAR-γ activation by rosiglitazone on lipid homeostasis at the adipose tissue-liver axis. Adult C57BL/6 male mice were pair fed liquid diet containing ethanol or isocaloric maltose dextrin for 8 wk with or without rosiglitazone supplementation to ethanol-fed mice for the last 3 wk. Ethanol exposure downregulated adipose PPAR-γ gene and reduced the WAT mass in association with induction of inflammation, which was attenuated by rosiglitazone. Ethanol exposure stimulated lipolysis but reduced fatty acid uptake capacity in association with dysregulation of lipid metabolism genes. Rosiglitazone normalized adipose gene expression and corrected ethanol-induced lipid dyshomeostasis. Ethanol exposure induced steatosis and upregulated inflammatory genes in the liver, which were attenuated by rosiglitazone. Hepatic peroxisomal fatty acid β-oxidation was suppressed by ethanol in associated with inhibition of acyl-coenzyme A oxidase 1. Rosiglitazone elevated plasma adiponectin level and normalized peroxisomal fatty acid β-oxidation rate. However, rosiglitazone did not affect ethanol-reduced very low-density lipoprotein secretion from the liver. These results demonstrated that activation of PPAR-γ by rosiglitazone reverses ethanol-induced adipose dysfunction and lipid dyshomeostasis at the WAT-liver axis, thereby abrogating alcoholic fatty liver.

Abstract P051: Induction of Cardiac Nitrosative Stress and Cell Death by Chronic Alcohol Consumption in an Angiotensin II-, PKC-, and NOX-Dependent Manner

Alcohol induced cardiac cell death is causative of cardiomyopathy, but the mechanisms responsible for alcoholic cardiac cell death remain largely unknown. We hypothesize that alcohol-induced Ang II plays a critical role in cardiac nitrosative stress, cell death and cardiomyopathy. To test this hypothesis, male C57BL/6 mice were pair-fed an alcohol or isocaloric maltose dextrin liquid diet for 2 months. Alcohol feeding caused significant cardiac cell death and nitrosative damage (shown by TUNEL positive cells, caspase-3 activation and protein nitration) and cardiac remodeling (shown by hypertrophy and fibrosis) along with increases in serum Ang II and cardiac AT1 expression. Mechanistic study in which cardiac H9c2 cells were treated with 100–400 mM alcohol for 24h revealed that alcohol exposure induced cell death, nitrosative damage and fibrosis, along with NADPH oxidase p47 phox (NOX) activation in a dose-dependent manner. Pre-treatment of alcohol-treated cells with NOX inhibitor (apycinin), peroxynitrite scavenger (urate), NOS inhibitor (L-NAME) and superoxide dismutase mimic (MnTMPyP) significantly abolished alcohol induced cell death. Furthermore, exposure to alcohol significantly up-regulated the expression of angiotensin II (Ang II) and its type 1 receptor (AT1) in these cultured cardiac cells. Either PKCα/β1 inhibitor or AT1 blocker completely prevented alcoholic NOX activation, and AT1 blocker inhibited the expression of PKCβ1, implying that alcoholic NOX activation is dependent of PKCα/β1 activation via AT1. To validate the in vitro findings, alcohol-fed and pair-fed mice were treated with MnTMPyP (5 mg/Kg) daily for 2 months, which did not change blood pressure, alcohol-induced cardiac PKC and NOX activation, but significantly prevented alcohol-induced cardiac nitrosative damage and cell death, along with a prevention of cardiac fibrosis and dysfunction. These results suggest that alcohol-induced cardiac cell death is mediated by up-regulated Ang II that via AT1 induces PKCα/β1-dependent NOX activation. The cardiac cell death plays a critical role in the development of alcoholic cardiomyopathy.

Comparative study on production of α-Amylase from Bacillus licheniformis strains

Alpha amylase (α-1, 4-glucan-glucanhydrolase, EC 3.2.1.1), an extracellular enzyme, degrades α, 1-4 glucosidic linkages of starch and related substrates in an endo-fashion producing oligosaccharides including maltose, glucose and alpha limit dextrin (7). The present study deals with the production and comparative study of production of α-amylase from two strains of Bacillus licheniformis, MTCC 2617 and 2618, by using four different substrates, starch, rice, wheat and ragi powder as carbon source by submerged fermentation. The effect of varying pH and incubation temperature, activator, inhibitor, and substrate concentration was investigated on the activity of α-amylase produced by MTCC strain 2618. The results shows that the production of the α-amylase by the B.licheniformis strain MTCC 2618, using four different substrates were found to be maximum (Starch 3.64 IU/ml/minutes, Rice powder 2.93 IU/ml/minutes, Wheat powder 2.67 IU/ml/minutes, Ragi powder 2.36 IU/ml/minutes) on comparing the enzyme production of two strains. It was also observed that the maximum production was found on the 3(rd) day (i.e. 72 hr) and characterization of crude enzyme revealed that optimum activity was at pH 7 and 37°C.

Lipidomic changes in rat liver after long-term exposure to ethanol

Alcoholic liver disease (ALD) is a serious health problem with significant morbidity and mortality. In this study we examined the progression of ALD along with lipidomic changes in rats fed ethanol for 2 and 3months to understand the mechanism, and identify possible biomarkers. Male Fischer 344 rats were fed 5% ethanol or caloric equivalent of maltose–dextrin in a Lieber-DeCarli diet. Animals were killed at the end of 2 and 3months and plasma and livers were collected. Portions of the liver were fixed for histological and immunohistological studies. Plasma and the liver lipids were extracted and analyzed by nuclear magnetic resonance (NMR) spectroscopy. A time dependent fatty infiltration was observed in the livers of ethanol-fed rats. Mild inflammation and oxidative stress were observed in some ethanol-fed rats at 3months. The multivariate and principal component analysis of proton and phosphorus NMR spectroscopy data of extracted lipids from the plasma and livers showed segregation of ethanol-fed groups from the pair-fed controls. Significant hepatic lipids that were increased by ethanol exposure included fatty acids and triglycerides, whereas phosphatidylcholine (PC) decreased. However, both free fatty acids and PC decreased in the plasma. In liver lipids unsaturation of fatty acyl chains increased, contrary to plasma, where it decreased. Our studies confirm that over-accumulation of lipids in ethanol-induced liver steatosis accompanied by mild inflammation on long duration of ethanol exposure. Identified metabolic profile using NMR lipidomics could be further explored to establish biomarker signatures representing the etiopathogenesis, progression and/or severity of ALD.

Maternal effects on ethanol teratogenesis in a cross between A/J and C57BL/6J mice

Genetic factors influence adverse pregnancy outcome in both humans and animal models. Animal research reveals that both the maternal and fetal genetic profiles are important for determining the risk of physical birth defects and prenatal mortality. Using a reciprocal-cross breeding design, we investigated whether the mother’s genes may be more important than fetal genes in determining risk for ethanol teratogenesis. Examination of possible synergistic genetic effects on ethanol teratogenesis was made possible by using two mouse strains known to be susceptible to specific malformations. Inbred A/J (A) and C57BL/6J (B6) mice were mated to produce four fetal genotype groups: the true-bred AċA and B6ċB6 genotypes and the genetically identical AċB6 and B6ċA genotypes (the F 1 genotype). Dams were administered either 5.8 g/kg ethanol or an isocaloric amount of maltose–dextrin on day 9 of pregnancy. Fetuses were removed by laparotomy on gestation day 18, weighed, and assessed for digit, vertebral, and kidney malformations. Digit malformations in the genetically identical F 1 ethanol-exposed litters showed a pattern consistent with a maternal genetic effect (AċB6 [2%] and B6ċA [30%]). In contrast, vertebral malformations were similar in all ethanol-exposed litters (AċA [26%], AċB6 [18%], B6ċA [22%], and B6ċB6 [33%]). The percentage of malformations did not differ between male and female fetuses, indicating sex-linked factors are not responsible for the maternal effect. Ethanol exposure decreased litter weights but did not affect litter mortality compared with maltose-exposed controls. This study supports the idea that genes influence malformation risk following in utero alcohol exposure. Specifically, maternal genes influence risk more than fetal genes for some teratogenic outcomes. No evidence supported synergistic genetic effects on ethanol teratogenesis. This research supports the conclusion that uterine environment contributes to determining risk of Fetal Alcohol Spectrum Disorder.