Translational Implications of the Alcohol-Metabolizing Enzymes, Including Cytochrome P450-2E1, in Alcoholic and Nonalcoholic Liver Disease

The Role of Phthalocyanine-Gold Nanoconjugates (Pc-Au NCs) in Ameliorating the Hepatic and Renal Toxicity-Induced by Silver Nanoparticles (Ag NPs) in Male Rats

Recently, gold nanoparticles (Au Nps) have gained tremendous attention for its unique properties as a safe nanocarrier for delivering drugs that are used in different disease diagnoses. Although silver nanoparticles (Ag NPs) have been generally applied due to their strong antibacterial, antiviral, antifungal, and antimicrobial properties, their toxicity is a subject of sustained debate, thus requiring further studies. The present study aims to evaluate the potential protective effect of gold nanoparticles and phthalocyanine-gold nanoconjugates (Pc-Au NCs) against the hepatorenal toxicity of silver nanoparticles in male rats. Herein, 60 adult male Rattus norvegicus rats were divided into six equal groups (n = 10/group); the first group was kept as control, the second received gold nanoparticles (Au NPs) intraperitoneally (10 µg/kg) daily for 3 weeks, the third group is gold-phthalocyanine (Pc-Au) group where rats were injected intraperitoneally with gold-phthalocyanine for 3 weeks (10 µg/kg), the fourth group received silver nanoparticles (Ag NPs) (4 mg/kg) daily intraperitoneally for 3 weeks, the fifth group is silver + gold nanoparticles group (Ag + Au), and the sixth is silver + gold-phthalocyanine nanoconjugates (Ag + Pc-Au) group in which rats were intraperitoneally injected firstly with Ag NPs (4 mg/kg) for 3 weeks then with gold or gold-phthalocyanine for another 3 weeks (10 µg/kg). Our results revealed that Ag NPs could increase the serum AST, ALT, ALP, urea, creatinine, and lipid profile and significantly decreased the total protein and albumin. Moreover, histopathological alterations detected in the kidney and the liver of the Ag NPs group included vascular congestion, inflammatory cell infiltration, and tissue distortion. Alongside, exposure to Ag NPs induces hepatic and renal oxidative stress by suppressing the antioxidant-related genes including glutathione peroxidase 1 (gpx1), superoxide dismutase (sod), and catalase (cat). Ag NPs also upregulated the hepatic and renal genes involved in inflammation such as the interleukin-6 (il-6) and tumor necrosis factor-α (tnf-α), nuclear factor kappa B (nf-κβ), apoptosis such as the BCL2 associated X (bax), casp3, and other related to metabolism including asparagine synthetase (asns), suppressor of cytokine signaling 3 (socs3), MYC proto-oncogene (myc), and C-C motif chemokine ligand 2 (ccl2). On the other hand, treatment with Au NPs and Pc-Au NCs could effectively ameliorate the hepatorenal damages induced by Ag NPs and improve liver and kidney architecture and function, especially in the Pc-Au NCs group. Briefly, our study revealed the underlined mechanism of Ag NPs hepatotoxic and nephrotoxic effects and that Pc-Au NCs could alleviate these adverse impacts via their anti-oxidative, anti-apoptotic, and anti-inflammatory activities.

Longitudinal profiling of the microbiome at four body sites reveals core stability and individualized dynamics during health and disease

To understand the dynamic interplay between the human microbiome and host during health and disease, we analyzed the microbial composition, temporal dynamics, and associations with host multi-omics, immune, and clinical markers of microbiomes from four body sites in 86 participants over 6 years. We found that microbiome stability and individuality are body-site specific and heavily influenced by the host. The stool and oral microbiome are more stable than the skin and nasal microbiomes, possibly due to their interaction with the host and environment. We identify individual-specific and commonly shared bacterial taxa, with individualized taxa showing greater stability. Interestingly, microbiome dynamics correlate across body sites, suggesting systemic dynamics influenced by host-microbial-environment interactions. Notably, insulin-resistant individuals show altered microbial stability and associations among microbiome, molecular markers, and clinical features, suggesting their disrupted interaction in metabolic disease. Our study offers comprehensive views of multi-site microbial dynamics and their relationship with host health and disease.

Longitudinal profiling of the microbiome at four body sites reveals core stability and individualized dynamics during health and disease

To understand dynamic interplay between the human microbiome and host during health and disease, we analyzed the microbial composition, temporal dynamics, and associations with host multi-omics, immune and clinical markers of microbiomes from four body sites in 86 participants over six years. We found that microbiome stability and individuality are body-site-specific and heavily influenced by the host. The stool and oral microbiome were more stable than the skin and nasal microbiomes, possibly due to their interaction with the host and environment. Also, we identified individual-specific and commonly shared bacterial taxa, with individualized taxa showing greater stability. Interestingly, microbiome dynamics correlated across body sites, suggesting systemic coordination influenced by host-microbial-environment interactions. Notably, insulin-resistant individuals showed altered microbial stability and associations between microbiome, molecular markers, and clinical features, suggesting their disrupted interaction in metabolic disease. Our study offers comprehensive views of multi-site microbial dynamics and their relationship with host health and disease.

Study Highlights

The stability of the human microbiome varies among individuals and body sites.Highly individualized microbial genera are more stable over time.At each of the four body sites, systematic interactions between the environment, the host and bacteria can be detected.Individuals with insulin resistance have lower microbiome stability, a more diversified skin microbiome, and significantly altered host-microbiome interactions.

Pathogenetic Pathways in Nonalcoholic Fatty Liver Disease: An Incomplete Jigsaw Puzzle

Nonalcoholic fatty liver disease (NAFLD)-a condition of excess fat accumulation in hepatocytes associated with metabolic dysfunction-has surpassed viral hepatitis to become the most prevalent chronic liver disease worldwide. As of now, only modestly effective pharmacological therapies for NAFLD exist. The uncomplete understanding of the pathophysiology underlying the heterogeneous disease spectrum known as NAFLD remains one of the major obstacles to the development of novel therapeutic approaches. This review compiles current knowledge on the principal signaling pathways and pathogenic mechanisms involved in NAFLD, which are analyzed in relation to its main pathological hallmarks (ie, hepatic steatosis, steatohepatitis, and liver fibrosis).

ALDH2 deficiency increases susceptibility to binge alcohol-induced gut leakiness, endotoxemia, and acute liver injury in mice through the gut-liver axis

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is the major enzyme responsible for metabolizing toxic acetaldehyde to acetate and acts as a protective or defensive protein against various disease states associated with alcohol use disorder (AUD), including alcohol-related liver disease (ARLD). We hypothesized that Aldh2-knockout (KO) mice are more susceptible to binge alcohol-mediated liver injury than wild-type (WT) mice through increased oxidative stress, gut leakiness and endotoxemia. Therefore, this study aimed to investigate the protective role of ALDH2 in binge alcohol-induced gut permeability, endotoxemia, and acute inflammatory liver injury by exposing Aldh2-KO or WT mice to a single oral dose of binge alcohol 3.5, 4.0, or 5.0 g/kg. Our findings showed for the first time that ALDH2 deficiency in Aldh2-KO mice increases their sensitivity to binge alcohol-induced oxidative and nitrative stress, enterocyte apoptosis, and nitration of gut tight junction (TJ) and adherent junction (AJ) proteins, leading to their degradation. These resulted in gut leakiness and endotoxemia in Aldh2-KO mice after exposure to a single dose of ethanol even at 3.5 g/kg, while no changes were observed in the corresponding WT mice. The elevated serum endotoxin (lipopolysaccharide, LPS) and bacterial translocation contributed to systemic inflammation, hepatocyte apoptosis, and subsequently acute liver injury through the gut-liver axis. Treatment with Daidzin, an ALDH2 inhibitor, exacerbated ethanol-induced cell permeability and reduced TJ/AJ proteins in T84 human colon cells. These changes were reversed by Alda-1, an ALDH2 activator. Furthermore, CRISPR/Cas9-mediated knockout of ALDH2 in T84 cells increased alcohol-mediated cell damage and paracellular permeability. All these findings demonstrate the critical role of ALDH2 in alcohol-induced epithelial barrier dysfunction and suggest that ALDH2 deficiency or gene mutation in humans is a risk factor for alcohol-mediated gut and liver injury, and that ALDH2 could be an important therapeutic target against alcohol-associated tissue or organ damage.

Binge drinking during the adolescence period causes oxidative damage-induced cardiometabolic disorders: A possible ameliorative approach with selenium supplementation

Binge drinking (BD) is the most common alcohol consumption model among adolescents. BD exposure during adolescence disrupts the nervous system function, being involved in the major mortality causes at this age: motor vehicle accidents, homicides and suicides. Recent studies have also shown that BD consumption during adolescence affects liver, renal and cardiovascular physiology, predisposing adolescents to future adult cardiometabolic damage. BD is a particularly pro-oxidant alcohol consumption pattern, because it leads to the production of a great source of reactive oxygen species (ROS) via the microsomal ethanol oxidizing system, also decreasing the antioxidant activity of glutathione peroxidase (GPx). Selenium (Se) is a mineral which plays a pivotal role against oxidation; it forms part of the catalytic center of different antioxidant selenoproteins such as GPxs (GPx1, GPx4, GPx3) and selenoprotein P (SelP). Specifically, GPx4 has an essential role in mitochondria, preventing their oxidation, apoptosis and NFkB-inflamative response, being this function even more relevant in heart's tissue. Se serum levels are decreased in acute and chronic alcoholic adult patients, being correlated to the severity of oxidation, liver damage and metabolic profile. Experimental studies have described that Se supplementation to alcohol exposed mice clearly decreases oxidative and liver damage. However, clinical BD effects on Se homeostasis and selenoproteins' tissue distribution related to oxidation during adolescence are not yet studied. In this narrative review we will describe the use of sodium selenite supplementation as an antioxidant therapy in adolescent BD rats in order to analyze Se homeostasis implication during BD exposure, oxidative balance, apoptosis and inflammation, mainly in liver, kidney, and heart. These biomolecular changes and the cardiovascular function will be analyzed. Se supplementation therapies could be a good strategy to prevent the oxidation, inflammation and apoptosis generated in tissues by BD during adolescence, such as liver, kidney and heart, improving cardiovascular functioning.

Identification of key genes associated with the progression of liver fibrosis to hepatocellular carcinoma based on iTRAQ proteomics and GEO database

INTRODUCTION AND OBJECTIVE

Liver fibrosis (LF) often leads to cirrhosis and even hepatocellular carcinoma (HCC), but the molecular mechanism remains unclear. The aims of the present study were to identify potential biomarkers for the progression of LF to HCC and explore the associated molecular mechanisms.

MATERIALS AND METHODS

The isobaric tags for relative and absolute quantitation (iTRAQ) was used to detect changes in the protein expression profiles of liver tissues and to screen the differentially expressed proteins (DEPs). The differentially expressed genes (DEGs) of LF rats and patients were screened by Gene Expression Database (GEO). Subsequently, the clinicopathological analysis of the overlapping genes in different pathological stages in HCC patients based on GEPIA database was conducted.

RESULTS

iTRAQ proteomic analysis revealed 689, 749 and 585 DEPs in the 6W, 8W and 12W groups, respectively. ALDH2, SLC27A5 and ASNS were not only the DEPs found in rats with LF with different stages but were also the DEGs related to the pathological stages and survival in patients with HCC.

CONCLUSIONS

ALDH2, SLC27A5 and ASNS were the potential biomarkers associated with the progression of LF to HCC.

Xenobiotic-Induced Aggravation of Metabolic-Associated Fatty Liver Disease

Metabolic-associated fatty liver disease (MAFLD), which is often linked to obesity, encompasses a large spectrum of hepatic lesions, including simple fatty liver, steatohepatitis, cirrhosis and hepatocellular carcinoma. Besides nutritional and genetic factors, different xenobiotics such as pharmaceuticals and environmental toxicants are suspected to aggravate MAFLD in obese individuals. More specifically, pre-existing fatty liver or steatohepatitis may worsen, or fatty liver may progress faster to steatohepatitis in treated patients, or exposed individuals. The mechanisms whereby xenobiotics can aggravate MAFLD are still poorly understood and are currently under deep investigations. Nevertheless, previous studies pointed to the role of different metabolic pathways and cellular events such as activation of de novo lipogenesis and mitochondrial dysfunction, mostly associated with reactive oxygen species overproduction. This review presents the available data gathered with some prototypic compounds with a focus on corticosteroids and rosiglitazone for pharmaceuticals as well as bisphenol A and perfluorooctanoic acid for endocrine disruptors. Although not typically considered as a xenobiotic, ethanol is also discussed because its abuse has dire consequences on obese liver.

Fructose and the Liver

Chronic diseases represent a major challenge in world health. Metabolic syndrome is a constellation of disturbances affecting several organs, and it has been proposed to be a liver-centered condition. Fructose overconsumption may result in insulin resistance, oxidative stress, inflammation, elevated uric acid levels, increased blood pressure, and increased triglyceride concentrations in both the blood and liver. Non-alcoholic fatty liver disease (NAFLD) is a term widely used to describe excessive fatty infiltration in the liver in the absence of alcohol, autoimmune disorders, or viral hepatitis; it is attributed to obesity, high sugar and fat consumption, and sedentarism. If untreated, NAFLD can progress to nonalcoholic steatohepatitis (NASH), characterized by inflammation and mild fibrosis in addition to fat infiltration and, eventually, advanced scar tissue deposition, cirrhosis, and finally liver cancer, which constitutes the culmination of the disease. Notably, fructose is recognized as a major mediator of NAFLD, as a significant correlation between fructose intake and the degree of inflammation and fibrosis has been found in preclinical and clinical studies. Moreover, fructose is a risk factor for liver cancer development. Interestingly, fructose induces a number of proinflammatory, fibrogenic, and oncogenic signaling pathways that explain its deleterious effects in the body, especially in the liver.

Effect of fucoidan on ethanol-induced liver injury and steatosis in mice and the underlying mechanism

BACKGROUND

Alcoholic liver disease is caused as a result of chronic alcohol consumption. In this study, we used an alcoholic liver injury mouse model to investigate the effect of fucoidan on ethanol-induced liver injury and steatosis and the underlying mechanisms.

METHODS

All mice were randomly divided into four groups: 1) control group, 2) model group, 3) diammonium glycyrrhizinate treatment group (200 mg/kg body weight), and 4) fucoidan treatment group (300 mg/kg body weight). Administration of ethanol for 8 weeks induced liver injury and steatosis in mice.

RESULTS

Fucoidan treatment decreased serum alanine aminotransferase activity, serum total cholesterol levels, and hepatic triglyceride levels, and improved the morphology of hepatic cells. Fucoidan treatment upregulated the expression of AMPKα1, SIRT1, and PGC-1α and inhibited the expression of ChREBP and HNF-1α. The levels of hepatic IL-6 and IL-18 were significantly decreased in the fucoidan group. Further, the levels of cytochrome P450-2E1 (CYP2E1), glucose-regulated protein (GRP) 78, and 3-nitrotyrosine (3-NT) in hepatic tissues were reduced in the fucoidan group as compared to the model group. Fucoidan significantly reversed the reduction of ileac Farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) levels induced by alcohol-feeding and reduced CYP7A1 (cholesterol 7α-hydroxylase) expression and total bile acid levels in the liver tissue. In addition, fucoidan regulated the structure of gut flora, with increased abundance of Prevotella and decreased abundance of Paraprevotella and Romboutsia as detected by 16S rDNA high-throughput sequencing.

CONCLUSION

Fucoidan inhibited alcohol-induced steatosis and disorders of bile acid metabolism in mice through the AMPKα1/SIRT1 pathway and the gut microbiota-bile acid-liver axis and protected against alcohol-induced liver injury in vivo.

Vinegar extract ameliorates alcohol-induced liver damage associated with the modulation of gut microbiota in mice

Vinegar extract is rich in phenolic compounds, which can prevent free radical-induced diseases. The aim of the present study was to explore the effects of vinegar extract on gut microbiota in alcohol-treated mice and their correlation with alcohol-induced liver damage. These results showed that vinegar extract regulated the gut microbiota composition and improved intestinal homeostasis through increasing the expression levels of ZO-1, occludin, claudin-1, Reg3b, and Reg3g in alcohol-treated mice. In addition, vinegar extract inhibited the alcohol-induced production of ROS and inflammatory factors. Moreover, Bacteroidetes, Verrucomicrobia, Akkermansia, and Lactobacillus showed a significant positive correlation with Reg3b, Reg3g, ZO-1, occludin, and claudin-1 and a negative correlation with hepatic inflammation and oxidative stress parameters. However, Firmicutes, Proteobacteria, Butyricimonas, Parabacteroides, and Bilophila exhibited the opposite effect. These findings suggest that vinegar extract modulates gut microbiota and improves intestinal homeostasis, and can be used as a novel gut microbiota manipulator against alcohol-induced liver damage.

Advanced glycation end products (AGEs) and other adducts in aging-related diseases and alcohol-mediated tissue injury

Advanced glycation end products (AGEs) are potentially harmful and heterogeneous molecules derived from nonenzymatic glycation. The pathological implications of AGEs are ascribed to their ability to promote oxidative stress, inflammation, and apoptosis. Recent studies in basic and translational research have revealed the contributing roles of AGEs in the development and progression of various aging-related pathological conditions, such as diabetes, cardiovascular complications, gut microbiome-associated illnesses, liver or neurodegenerative diseases, and cancer. Excessive chronic and/or acute binge consumption of alcohol (ethanol), a widely consumed addictive substance, is known to cause more than 200 diseases, including alcohol use disorder (addiction), alcoholic liver disease, and brain damage. However, despite the considerable amount of research in this area, the underlying molecular mechanisms by which alcohol abuse causes cellular toxicity and organ damage remain to be further characterized. In this review, we first briefly describe the properties of AGEs: their formation, accumulation, and receptor interactions. We then focus on the causative functions of AGEs that impact various aging-related diseases. We also highlight the biological connection of AGE-alcohol-adduct formations to alcohol-mediated tissue injury. Finally, we describe the potential translational research opportunities for treatment of various AGE- and/or alcohol-related adduct-associated disorders according to the mechanistic insights presented.

Genetic variants associated with alcohol dependence co-ordinate regulation of ADH genes in gastrointestinal and adipose tissues

GWAS studies have identified genetic variants associated with Alcohol Dependence (AD), but how they link to genes, their regulation and disease traits, remains largely unexplored. Here we integrated information on the 3D genome organization with expression quantitative loci (eQTLs) analysis, using CoDeS3D, to identify the functional impacts of single nucleotide polymorphisms associated with AD (p < 1 × 10-6). We report that 42% of the 285 significant tissue-specific regulatory interactions we identify were associated with four genes encoding Alcohol Dehydrogenase - ADH1A, ADH1B, ADH1C and ADH4. Identified eQTLs produced a co-ordinated regulatory action between ADH genes, especially between ADH1A and ADH1C within the subcutaneous adipose and gastrointestinal tissues. Five eQTLs were associated with regulatory motif alterations and tissue-specific histone marks consistent with these variants falling in enhancer and promoter regions. By contrast, few regulatory connections were identified in the stomach and liver. This suggests that changes in gene regulation associated with AD are linked to changes in tissues other than the primary sites of alcohol absorption and metabolism. Future work to functionally characterise the putative regulatory regions we have identified and their links to metabolic and regulatory changes in genes will improve our mechanistic understanding of AD disease development and progression.

Alcohol Metabolizing Enzymes, Microsomal Ethanol Oxidizing System, Cytochrome P450 2E1, Catalase, and Aldehyde Dehydrogenase in Alcohol-Associated Liver Disease

Once ingested, most of the alcohol is metabolized in the liver by alcohol dehydrogenase to acetaldehyde. Two additional pathways of acetaldehyde generation are by microsomal ethanol oxidizing system (cytochrome P450 2E1) and catalase. Acetaldehyde can form adducts which can interfere with cellular function, leading to alcohol-induced liver injury. The variants of alcohol metabolizing genes encode enzymes with varied kinetic properties and result in the different rate of alcohol elimination and acetaldehyde generation. Allelic variants of these genes with higher enzymatic activity are believed to be able to modify susceptibility to alcohol-induced liver injury; however, the human studies on the association of these variants and alcohol-associated liver disease are inconclusive. In addition to acetaldehyde, the shift in the redox state during alcohol elimination may also link to other pathways resulting in activation of downstream signaling leading to liver injury.

Contributing Roles of CYP2E1 and Other Cytochrome P450 Isoforms in Alcohol-Related Tissue Injury and Carcinogenesis

The purpose of this review is to briefly summarize the roles of alcohol (ethanol) and related compounds in promoting cancer and inflammatory injury in many tissues. Long-term chronic heavy alcohol exposure is known to increase the chances of inflammation, oxidative DNA damage, and cancer development in many organs. The rates of alcohol-mediated organ damage and cancer risks are significantly elevated in the presence of co-morbidity factors such as poor nutrition, unhealthy diets, smoking, infection with bacteria or viruses, and exposure to pro-carcinogens. Chronic ingestion of alcohol and its metabolite acetaldehyde may initiate and/or promote the development of cancer in the liver, oral cavity, esophagus, stomach, gastrointestinal tract, pancreas, prostate, and female breast. In this chapter, we summarize the important roles of ethanol/acetaldehyde in promoting inflammatory injury and carcinogenesis in several tissues. We also review the updated roles of the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and other cytochrome P450 isozymes in the metabolism of various potentially toxic substrates, and consequent toxicities, including carcinogenesis in different tissues. We also briefly describe the potential implications of endogenous ethanol produced by gut bacteria, as frequently observed in the experimental models and patients of nonalcoholic fatty liver disease, in promoting DNA mutation and cancer development in the liver and other tissues, including the gastrointestinal tract.

Alcohol Metabolism in the Progression of Human Nonalcoholic Steatohepatitis

Alcohol metabolism is a well-characterized biological process that is dominated by the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) families. Nonalcoholic steatohepatitis (NASH) is the advanced inflammatory stage of nonalcoholic fatty liver disease (NAFLD) and is known to alter the metabolism and disposition of numerous drugs. The purpose of this study was to investigate the alterations in alcohol metabolism processes in response to human NASH progression. Expression and function of ADHs, ALDHs, and catalase were examined in normal, steatosis, NASH (fatty) and NASH (not fatty) human liver samples. ALDH4A1 mRNA was significantly decreased in both NASH groups, while no significant changes were observed in the mRNA levels of other alcohol-related enzymes. The protein levels of ADH1A, ADH1B, and ADH4 were each decreased in the NASH groups, which was consistent with a decreased overall ADH activity. The protein level of ALDH2 was significantly increased in both NASH groups, while ALDH1A1 and ALDH1B1 were only decreased in NASH (fatty) samples. ALDH activity represented by oxidation of acetaldehyde was decreased in the NASH (fatty) group. The protein level of catalase was decreased in both NASH groups, though activity was unchanged. Furthermore, the significant accumulation of 4-hydroxynonenal protein adduct in NASH indicated significant oxidative stress and a potential reduction in ALDH activity. Collectively, ADH and ALDH expression and function are profoundly altered in the progression of NASH, which may have a notable impact on ADH- and ALDH-associated cellular metabolism processes and lead to significant alterations in drug metabolism mediated by these enzymes.

Hepatoprotective Effects of Morchella esculenta against Alcohol-Induced Acute Liver Injury in the C57BL/6 Mouse Related to Nrf-2 and NF-κB Signaling

This study investigated the hepatoprotective effects of Morchella esculenta fruit body (ME) and the underlying mechanisms in mice with alcohol-induced acute liver injury. Systematic analysis revealed that ME contained 21 types of fatty acid, 17 types of amino acid, and 12 types of mineral. Subsequently, a mouse model of acute alcohol-induced liver injury was established by oral administration of alcohol for 14 days. Fourteen-day administration of ME prevented alcohol-induced increases in alanine aminotransferase and aspartate aminotransferase levels and reduced the activity of acetaldehyde dehydrogenase in blood serum and liver tissue. ME appears to regulate lipid metabolism by suppressing triglycerides, total cholesterol, and high-density lipoprotein in the liver. ME inhibited the production of inflammatory factors including chitinase-3-like protein 1 (YKL 40), interleukin-7 (IL-7), plasminogen activator inhibitor type 1 (PAI-1), and retinol-binding protein 4 (RBP4) in blood serum and/or liver tissue. ME treatment relieved the alcohol-induced imbalance in prooxidative and antioxidative signaling via nuclear factor-erythroid 2-related factor 2 (Nrf-2), as indicated by upregulation of superoxide dismutase-1, superoxide dismutase-2, catalase, heme oxygenase-1, and heme oxygenase-2 expression and downregulation of kelch-like ECH-associated protein 1 (Keap-1) in the liver. Moreover, ME reduced the levels of phosphorylated nuclear factor kappa-B kinase α/β, inhibitor of nuclear factor kappa-B α and nuclear factor kappa-B p65 (NF-κB p65) in the liver. The hepatoprotective effects of ME against alcohol-induced acute liver injury were thus confirmed. The mechanism of action may be related to modulation of antioxidative and anti-inflammatory signaling pathways, partially via regulation of Nrf-2 and NF-κB signaling.

Comparing the protective effects of three sulfur compounds against acrylonitrile-induced acute toxicity in CYP2E1-induced rats

Cytochrome P450 2E1 (CYP2E1) can be induced by diabetes mellitus, nonalcoholic liver disease, and obesity. This study assessed the protective effects of three sulfur compounds, namely phenethyl isothiocyanate (PEITC), dimethyl trisulfide (DMTS), and sodium thiosulfate (STS), on acrylonitrile (ACN)-induced acute toxicity in rats enriched with CYP2E1. PEITC and DMTS were administered intragastrically (i.g.), whereas STS was injected intraperitoneally (i.p.) at an identical dose of 0.5 mmol/kg for 3 days in acetone-pretreated rats before ACN (90 mg/kg) injection (i.p.). Acetone-treated rats that expressed high levels of CYP2E1 were more susceptible to ACN-induced acute toxicity. The sulfur compounds reduced the rate of convulsions and loss of the righting reflex in acute ACN-exposed CYP2E1-induced rats; PEITC and DMTS also increased the survival rates. PEITC inhibited hepatic CYP2E1 activity and protected hepatic and cerebral cytochrome c oxidase (CcOx) activities in acute ACN-exposed CYP2E1-enriched rats; DMTS protected hepatic CcOx activity. DMTS attenuated ACN-induced oxidative injury by reducing malondialdehyde (MDA) levels and increasing glutathione content in the brain. STS only reduced cerebral MDA levels, whereas PEITC did not exhibit any antioxidant effects. Collectively, PEITC provided superior protective effects against ACN-induced acute toxicity in rats with increased CYP2E1 activity, followed by DMTS; STS provided limited effects. PEITC and DMTS might be considered as promising chemopreventive agents against ACN-induced acute toxicity in vulnerable subpopulations with increased CYP2E1 activity.

Role of Alcohol Oxidative Metabolism in Its Cardiovascular and Autonomic Effects

Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.

Mechanisms involved in the death of steatotic WIF-B9 hepatocytes co-exposed to benzo[a]pyrene and ethanol: a possible key role for xenobiotic metabolism and nitric oxide

We previously demonstrated that co-exposing pre-steatotic hepatocytes to benzo[a]pyrene (B[a]P), a carcinogenic environmental pollutant, and ethanol, favored cell death. Here, the intracellular mechanisms underlying this toxicity were studied. Steatotic WIF-B9 hepatocytes, obtained by a 48h-supplementation with fatty acids, were then exposed to B[a]P/ethanol (10 nM/5 mM, respectively) for 5 days. Nitric oxide (NO) was demonstrated to be a pivotal player in the cell death caused by the co-exposure in steatotic hepatocytes. Indeed, by scavenging NO, CPTIO treatment of co-exposed steatotic cells prevented not only the increase in DNA damage and cell death, but also the decrease in the activity of CYP1, major cytochrome P450s of B[a]P metabolism. This would then lead to an elevation of B[a]P levels, thus possibly suggesting a long-lasting stimulation of the transcription factor AhR. Besides, as NO can react with superoxide anion to produce peroxynitrite, a highly oxidative compound, the use of FeTPPS to inhibit its formation indicated its participation in DNA damage and cell death, further highlighting the important role of NO. Finally, a possible key role for AhR was pointed out by using its antagonist, CH-223191. Indeed it prevented the elevation of ADH activity, known to participate to the ethanol production of ROS, notably superoxide anion. The transcription factor, NFκB, known to be activated by ROS, was shown to be involved in the increase in iNOS expression. Altogether, these data strongly suggested cooperative mechanistic interactions between B[a]P via AhR and ethanol via ROS production, to favor cell death in the context of prior steatosis.

Effect of Diabetes Mellitus on the Pharmacokinetics and Pharmacodynamics of Tuberculosis Treatment

Diabetes mellitus (DM) and tuberculosis (TB) are two common diseases with increasing geographic overlap and clinical interactions. The effect of DM and hemoglobin A1c (HbA1c) values on the pharmacokinetics (PK) and pharmacodynamics (PD) of anti-TB drugs remains poorly characterized. Newly diagnosed TB patients with and without DM starting fixed-dose, thrice-weekly treatment underwent sampling for PK assessments (predose and 0.5, 2, and 6 h postdose) during the intensive and continuation phases of treatment. The effect of DM and HbA1c values on the maximum concentration (C _max) of rifampin, isoniazid, and pyrazinamide and the association between drug concentrations and microbiologic and clinical outcomes were assessed. Of 243 patients, 101 had DM. Univariate analysis showed significant reductions in the C _max of pyrazinamide and isoniazid (but not rifampin) with DM or increasing HbA1c values. After adjusting for age, sex, and weight, DM was associated only with reduced pyrazinamide concentrations (adjusted geometric mean ratio = 0.74, P = 0.03). In adjusted Cox models, female gender (adjusted hazards ratio [aHR] = 1.75, P = 0.001), a lower smear grade with the Xpert assay (aHR = 1.40, P < 0.001), and the pyrazinamide C _max (aHR = 0.99, P = 0.006) were independent predictors of sputum culture conversion to negative. Higher isoniazid or rifampin concentrations were associated with a faster time to culture conversion in patients with DM only. A pyrazinamide C _max above the therapeutic target was associated with higher unfavorable outcomes (treatment failure, relapse, death) (odds ratio = 1.92, P = 0.04). DM and higher HbA1c values increased the risk of not achieving therapeutic targets for pyrazinamide (but not rifampin or isoniazid). Higher pyrazinamide concentrations, though, were associated with worse microbiologic and clinical outcomes. DM status also appeared to influence PK-PD relationships for isoniazid and rifampin.

Higher Activity of Alcohol Dehydrogenase Is Correlated with Hepatic Fibrogenesis

Hepatofibrosis can progress to cirrhosis and hepatocellular carcinoma (HCC). Prevention, stabilization, and reversal of disease progression are vital for patients with hepatofibrosis, and identifying the risk factors for hepatofibrosis is urgently needed. In this study, we examined the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the fibrotic livers of HCC patients (n = 88) and comparied these results with activities in patients with normal livers (n = 74). A fibrosis-carcinoma rat model was used to study the activity of ADH in fibrosis and HCC and the relationship between innate ADH activity and the extent of hepatofibrosis or HCC. Substantial interindividual variations were found in the activities of ADH and ALDH in normal livers. The activity levels of total ADH, ADHI, and ADHII in fibrotic livers were significantly higher than those in normal livers (P < 0.001), whereas the activity of ALDH was slightly greater. The positive rates of ADHI and ADHII were 84.1% and 77.3%, respectively; the areas under the receiver operator characteristics (ROC) curve were 0.943 and 0.912, respectively. For the rat model compared with controls, ADH activity in liver was significantly increased at the fibrotic and HCC stages, and no significant difference was noted between ADH activity in the liver at these two stages. The innate activity of ADH in serum was well correlated with the extent of hepatofibrosis as indicated by Masson area%, Ki67⁺%, proliferating cell nuclear antigen ⁺%, and GST-p average density at fibrotic stage but not at HCC stage. A higher level of activity of ADH is a risk factor for hepatofibrogenesis and might be a prevention target for hepatofibrosis.

Pomegranate prevents binge alcohol-induced gut leakiness and hepatic inflammation by suppressing oxidative and nitrative stress

Alcoholic liver disease (ALD) is a major chronic liver disease worldwide and can range from simple steatosis, inflammation to fibrosis/cirrhosis possibly through leaky gut and systemic endotoxemia. We investigated whether pomegranate (POM) protects against binge alcohol-induced gut leakiness, endotoxemia, and inflammatory liver damage. After POM pretreatment for 10 days, rats were exposed to 3 oral doses of binge alcohol (5 g/kg/dose) or dextrose (as control) at 12-h intervals. Binge alcohol exposure induced leaky gut with significantly elevated plasma endotoxin and inflammatory fatty liver by increasing the levels of oxidative and nitrative stress marker proteins such as ethanol-inducible CYP2E1, inducible nitric oxide synthase, and nitrated proteins in the small intestine and liver. POM pretreatment significantly reduced the alcohol-induced gut barrier dysfunction, plasma endotoxin and inflammatory liver disease by inhibiting the elevated oxidative and nitrative stress marker proteins. POM pretreatment significantly restored the levels of intestinal tight junction (TJ) proteins such as ZO-1, occludin, claudin-1, and claundin-3 markedly diminished after alcohol-exposure. In addition, the levels of gut adherent junction (AJ) proteins (e.g., β-catenin and E-cadherin) and desmosome plakoglobin along with associated protein α-tubulin were clearly decreased in binge alcohol-exposed rats but restored to basal levels in POM-pretreated rats. Immunoprecipitation followed by immunoblot analyses revealed that intestinal claudin-1 protein was nitrated and ubiquitinated in alcohol-exposed rats, whereas these modifications were significantly blocked by POM pretreatment. These results showed for the first time that POM can prevent alcohol-induced gut leakiness and inflammatory liver injury by suppressing oxidative and nitrative stress.

Red mulberry fruit aqueous extract and silk proteins accelerate acute ethanol metabolism and promote the anti‑oxidant enzyme systems in rats

Red mulberry (Morus alba) fruit is rich in anthocyanins, and mulberry leaves are used by silk worms to make silk protein. We determined that the water and ethanol extract of mulberry fruit and silk amino acids accelerated ethanol degradation and suppressed temporal cognitive dysfunction in acute alcohol administered rats. The mechanism was explored in rats with acute oral administration of silk protein and mulberry fruit extracts. Rats were given 0.3 g of dextrin (control) and water extract (WMB) and ethanol extract of mulberry (EMB), silk protein hydrolysates (SKA), and a commercial product (positive‑control) based on body weight. After 30 min, rats were administered 3 g ethanol/kg body weight and serum ethanol and acetaldehyde levels were measured. After 3 h movements were measured with a video tracking system and at 5 h cognitive function was measured by Y maze test. WMB contain much higher rutin, luteolin and quercetins than EMB. In SKA rats, serum alcohol concentrations slowly increased until 60 min, but were markedly elevated until 120 min. However, WMB rats exhibited rapidly increased serum alcohol levels until 60 min and showed the lowest peak of serum alcohol levels, indicating the highest degradation of alcohol. The patterns of serum acetaldehyde levels were similar to those of serum ethanol levels but WMB was more effective for reducing serum acetaldehyde levels than serum ethanol levels. WMB was most effective for increasing mRNA expression of alcohol dehydrogenase and acetaldehyde dehydrogenase. WMB and SKA decreased lipid peroxides by increasing activities of SOD and GSH‑Px in the liver and they also reduced pro‑inflammatory cytokines such as tumor necrosis factor‑α and interleukin‑6. WMB and SKA exerted better anti‑oxidant effects than the positive‑control. WMB containing higher flavonoids reduced pro‑inflammatory cytokines better than SKA. In conclusions, both WMB and SKA might reduce acute alcohol‑induced hangover and liver and brain damage by lowering serum alcohol and acetaldehyde levels.

Preventive effects of indole-3-carbinol against alcohol-induced liver injury in mice via antioxidant, anti-inflammatory, and anti-apoptotic mechanisms: Role of gut-liver-adipose tissue axis

Indole-3-carbinol (I3C), found in Brassica family vegetables, exhibits antioxidant, anti-inflammatory, and anti-cancerous properties. Here, we aimed to evaluate the preventive effects of I3C against ethanol (EtOH)-induced liver injury and study the protective mechanism(s) by using the well-established chronic-plus-binge alcohol exposure model. The preventive effects of I3C were evaluated by conducting various histological, biochemical, and real-time PCR analyses in mouse liver, adipose tissue, and colon, since functional alterations of adipose tissue and intestine can also participate in promoting EtOH-induced liver damage. Daily treatment with I3C alleviated EtOH-induced liver injury and hepatocyte apoptosis, but not steatosis, by attenuating elevated oxidative stress, as evidenced by the decreased levels of hepatic lipid peroxidation, hydrogen peroxide, CYP2E1, NADPH-oxidase, and protein acetylation with maintenance of mitochondrial complex I, II, and III protein levels and activities. I3C also restored the hepatic antioxidant capacity by preventing EtOH-induced suppression of glutathione contents and mitochondrial aldehyde dehydrogenase-2 activity. I3C preventive effects were also achieved by attenuating the increased levels of hepatic proinflammatory cytokines, including IL1β, and neutrophil infiltration. I3C also attenuated EtOH-induced gut leakiness with decreased serum endotoxin levels through preventing EtOH-induced oxidative stress, apoptosis of enterocytes, and alteration of tight junction protein claudin-1. Furthermore, I3C alleviated adipose tissue inflammation and decreased free fatty acid release. Collectively, I3C prevented EtOH-induced liver injury via attenuating the damaging effect of ethanol on the gut-liver-adipose tissue axis. Therefore, I3C may also have a high potential for translational research in treating or preventing other types of hepatic injury associated with oxidative stress and inflammation.

CYP2E1 Gene Polymorphisms Related to the Formation of Coronary Artery Lesions in Kawasaki Disease

BACKGROUND

Kawasaki disease (KD) is an acute febrile systemic vasculitis that disturbs coronary arteries. Patients' risks of adverse cardiovascular events and subclinical atherosclerosis have been found to significantly increase with polymorphisms of the human cytochrome P450. This current study aims to research the possible relationship between cytochrome P450, family 2, subfamily E and polypeptide 1 (CYP2E1) polymorphisms with KD.

METHODS

We selected 6 tag single-nucleotide polymorphisms (SNPs) of the CYP2E1 gene for TaqMan allelic discrimination assay in 340 KD patients and performed analysis on the clinical phenotypes and coronary artery lesions (CALs). CAL associations of tag SNPs were adjusted for age and gender in the logistic regression.

RESULTS

The KD patients with a CC genotype of rs915906 demonstrated a greater proportion of CAL formation (P = 0.009). Furthermore, the GG genotype frequencies of rs2070676 showed a significantly greater risk for CAL formation in KD patients (P = 0.007). However, the SNPs of the CYP2E1 gene did not influence CAL formation in the participating KD patients either with or without high-dose acetylsalicylic acid. Using the expression quantitative trait locus analyses, we found that the SNPs associated with CAL formation in KD also affected CYP2E1 expression in certain cell types.

CONCLUSION

This study is the first to find that the risk of CAL formation is related to CYP2E1 gene polymorphisms in KD patients.

Aqueous Extract of Gynura Bicolor Attenuated Hepatic Steatosis, Glycative, Oxidative, and Inflammatory Injury Induced by Chronic Ethanol Consumption in Mice

Gynura bicolor leaf aqueous extract (GAE) is rich in phytochemicals including phenolic acids, flavonoids, carotenoids, and anthocyanins. Effects of GAE upon hepatic injury in mice with chronic ethanol intake were examined. Lieber-DeCarli liquid diet with ethanol was used to induce hepatic lipid accumulation, oxidative, glycative, and inflammatory injury. GAE at 0.25% or 0.5% was added in feeds, and supplied to mice consumed Lieber-DeCarli liquid diet with ethanol for 6 wk. Blood and liver were collected for analyses. Results showed that ethanol increased plasma and hepatic triglyceride and cholesterol content, and affected plasma levels of insulin, adiponectin, leptin, and ghrelin. GAE at both doses decreased lipid accumulation, and at high dose improved hormones abnormality. Histological data revealed that GAE supplement mitigated hepatic lipid deposit. Ethanol increased plasma N^ε -(carboxyethymethyl)-lysine and pentosidine levels. GAE at high doses lowered those glycative factors. Ethanol depleted glutathione content, increased CYP2E1 activity and reactive oxygen species production, and reduced the activity of glutathione peroxide, glutathione reductase and catalase in liver. GAE supplement at both doses reversed these alterations and attenuated hepatic oxidative stress. GAE supplement also at both doses decreased hepatic inflammatory cytokines release in ethanol treated mice. These findings support that leaves of G. bicolor is a functional food with liver protective activities against ethanol.

Increased ethanol-inducible cytochrome P450-2E1 and cytochrome P450 isoforms in exosomes of alcohol-exposed rodents and patients with alcoholism through oxidative and endoplasmic reticulum stress

This study investigated the role of ethanol‐inducible cytochrome P450‐2E1 (CYP2E1) in enhancing CYP2E1 and other P450 proteins in extracellular vesicles (EVs) from alcohol‐exposed rodents and human patients with alcoholism and their effects on oxidative hepatocyte injury. Female Fischer rats and wild‐type or Cyp2e1‐null mice were exposed to three oral doses of binge ethanol or dextrose control at 12‐hour intervals. Plasma EV and hepatic proteins from alcohol‐exposed rodents, patients with alcoholism, and their respective controls were isolated and characterized. The number of EVs and the amounts of EV CYP2E1, CYP2A, CYP1A1/2, and CYP4B proteins were markedly elevated in both patients with alcoholism and alcohol‐exposed rats and mice. The number of EVs and EV P450 proteins were significantly reduced in ethanol‐exposed rats fed a diet containing polyunsaturated fatty acids. The increased number of EVs and EV CYP2E1 and other P450 isoforms in alcohol‐exposed wild types were significantly reduced in the corresponding Cyp2e1‐null mice. EV CYP2E1 amounts depended on increased oxidative and endoplasmic reticulum (ER) stress because their levels were decreased by cotreatment with the antioxidant N‐acetylcysteine or the CYP2E1 inhibitor chlormethiazole but increased by ER stress‐inducer thapsigargin, which was blocked by 4‐phenylbutyric acid. Furthermore, cell death rates were elevated when primary hepatocytes or human hepatoma cells were exposed to EVs from alcohol‐exposed rodents and patients with alcoholism, demonstrating that EVs from alcohol‐exposed rats and patients with alcoholism are functional and can promote cell death by activating the apoptosis signaling pathway, including phospho‐c‐Jun N‐terminal kinase, proapoptotic Bax, and activated caspase‐3. Conclusion: CYP2E1 has an important role in elevating EV CYP2E1 and other P450 isoforms through increased oxidative and ER stress. Elevated EV‐CYP2E1 detected after withdrawal from alcohol or exposure to the CYP2E1 inducer pyrazole can be a potential biomarker for liver injury. (Hepatology Communications 2017;1:675–690)

Role of nonalcoholic fatty liver disease as risk factor for drug-induced hepatotoxicity

BACKGROUND

Obesity is often associated with nonalcoholic fatty liver disease (NAFLD), which refers to a large spectrum of hepatic lesions including fatty liver, nonalcoholic steatohepatitis (NASH) and cirrhosis. Different investigations showed or suggested that obesity and NAFLD are able to increase the risk of hepatotoxicity of different drugs. Some of these drugs could induce more frequently an acute hepatitis in obese individuals whereas others could worsen pre-existing NAFLD.

AIM

The main objective of the present review was to collect the available information regarding the role of NAFLD as risk factor for drug-induced hepatotoxicity. For this purpose, we performed a data-mining analysis using different queries including drug-induced liver injury (or DILI), drug-induced hepatotoxicity, fatty liver, nonalcoholic fatty liver disease (or NAFLD), steatosis and obesity. The main data from the collected articles are reported in this review and when available, some pathophysiological hypotheses are put forward.

RELEVANCE FOR PATIENTS

Drugs that could pose a potential risk in obese patients include compounds belonging to different pharmacological classes such as acetaminophen, halothane, methotrexate, rosiglitazone, stavudine and tamoxifen. For some of these drugs, experimental investigations in obese rodents confirmed the clinical observations and unveiled different pathophysiological mechanisms which could explain why these pharmaceuticals are particularly hepatotoxic in obesity and NAFLD. Other drugs such as pentoxifylline, phenobarbital and omeprazole might also pose a risk but more investigations are required to determine whether this risk is significant or not. Because obese people often take several drugs for the treatment of different obesity-related diseases such as type 2 diabetes, hyperlipidemia and coronary heart disease, it is urgent to identify the main pharmaceuticals that can cause acute hepatitis on a fatty liver background or induce NAFLD worsening.

Limited Excessive Voluntary Alcohol Drinking Leads to Liver Dysfunction in Mice

BACKGROUND

Liver damage is a serious and sometimes fatal consequence of long-term alcohol intake, which progresses from early-stage fatty liver (steatosis) to later-stage steatohepatitis with inflammation and fibrosis/necrosis. However, very little is known about earlier stages of liver disruption that may occur in problem drinkers, those who drink excessively but are not dependent on alcohol.

METHODS

We examined how repeated binge-like alcohol drinking in C57BL/6 mice altered liver function, as compared with a single binge-intake session and with repeated moderate alcohol consumption. We measured a number of markers associated with early- and later-stage liver disruption, including liver steatosis, measures of liver cytochrome P4502E1 (CYP2E1) and alcohol dehydrogenase (ADH), alcohol metabolism, expression of cytokine mRNA, accumulation of 4-hydroxynonenal (4-HNE) as an indicator of oxidative stress, and alanine transaminase/aspartate transaminase as a measure of hepatocyte injury.

RESULTS

Importantly, repeated binge-like alcohol drinking increased triglyceride levels in the liver and plasma, and increased lipid droplets in the liver, indicators of steatosis. In contrast, a single binge-intake session or repeated moderate alcohol consumption did not alter triglyceride levels. In addition, alcohol exposure can increase rates of alcohol metabolism through CYP2E1 and ADH, which can potentially increase oxidative stress and liver dysfunction. Intermittent, excessive alcohol intake increased liver CYP2E1 mRNA, protein, and activity, as well as ADH mRNA and activity. Furthermore, repeated, binge-like drinking, but not a single binge or moderate drinking, increased alcohol metabolism. Finally, repeated, excessive intake transiently elevated mRNA for the proinflammatory cytokine IL-1B and 4-HNE levels, but did not alter markers of later-stage liver hepatocyte injury.

CONCLUSIONS

Together, we provide data suggesting that even relatively limited binge-like alcohol drinking can lead to disruptions in liver function, which might facilitate the transition to more severe forms of liver damage.

miR-224 Affects Mammary Epithelial Cell Apoptosis and Triglyceride Production by Downregulating ACADM and ALDH2 Genes

MicroRNAs (miRNAs) are small noncoding RNA molecules that involve in various biological functions by regulating the expressions of target genes. In recent years, many researchers have demonstrated that miR-224 played an important role in regulating lipid metabolism. Therefore, in this study, the target genes of miR-224 were verified and the regulatory role of miR-224 was confirmed in lipid metabolism. In this study, bioinformatics methods were used for primarily predicting the target gene of miR-224 and dual-luciferase reporter system was used for further verify the relationship between miR-224 and its target gene. Then, the miR-224 mimics, miR-224 inhibitor, and miRNA-ShNC were transfected into mammary epithelial cells (MECs), respectively, and the expression of miR-224 and its target genes was detected by quantitative real-time polymerase chain reaction and Western blot. Furthermore, the triglyceride production and cell apoptosis were detected by triglyceride mensuration reagent kit using flow cytometry. The results showed that ACADM and ALDH2 were predicted to be the target genes of miR-224, primarily by bioinformatics analysis. We founded that miR-224 could recognize with ACADM-3'UTR and ALDH2-3'UTR, indicating that the target sites existed in 3'UTR of ACADM and ALDH2. And then, the expressions of miR-224 had negative trend with the levels of ACADM and ALDH2, suggesting that miR-224 could downregulate the expressions of ACADM and ALDH2. Finally, the triglyceride production decreased and apoptosis rate increased after the overexpression of miR-224 in MECs. The above results indicated that miR-224 regulating target genes in lipid metabolism might be used as a new pathway for better breeding.

Inhibitory effect of Sophora subprosrate polysaccharide on mitochondria oxidative stress induced by PCV-2 infection in RAW264.7 cells

In the present study, the inhibitory effect of Sophora subprosrate polysaccharide (SSP) on PCV-2-induced mitochondrial respiratory burst in RAW264.7 cells was first investigated. The findings suggested that SOD activity and the anti-superoxide anion radical activity of the RAW264.7 cells were significantly decreased after PCV-2 infection, and MnSOD mRNA levels were significantly decreased, while NOX2 mRNA levels and protein expression were increased. Meanwhile, the O₂^•- levels and mitochondrial membrane potentials were significantly increased. After treatment with SSP, significant increases in the activities of SOD, anti-superoxide anion radical activities, and MnSOD mRNA levels in the PCV-2 infected cells were observed. Meanwhile, significant increases in NOX2 mRNA levels and protein expression, O₂^•- levels and mitochondrial membrane potentials were also observed. The results showed that PCV2 infection resulted in the mitochondria oxidative stress of RAW264.7 cells as indicated by an increasing mitochondrial membrane potential, which was then inhibited by SSP. It was concluded that RAW264.7 cells treated with SSP could suffer from mitochondrial damage, which may be mediated by the inhibition of the mitochondrial membrane potential.

Mitochondrial dysfunction and cell death in neurodegenerative diseases through nitroxidative stress

Mitochondria are important for providing cellular energy ATP through the oxidative phosphorylation pathway. They are also critical in regulating many cellular functions including the fatty acid oxidation, the metabolism of glutamate and urea, the anti-oxidant defense, and the apoptosis pathway. Mitochondria are an important source of reactive oxygen species leaked from the electron transport chain while they are susceptible to oxidative damage, leading to mitochondrial dysfunction and tissue injury. In fact, impaired mitochondrial function is commonly observed in many types of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, alcoholic dementia, brain ischemia-reperfusion related injury, and others, although many of these neurological disorders have unique etiological factors. Mitochondrial dysfunction under many pathological conditions is likely to be promoted by increased nitroxidative stress, which can stimulate post-translational modifications (PTMs) of mitochondrial proteins and/or oxidative damage to mitochondrial DNA and lipids. Furthermore, recent studies have demonstrated that various antioxidants, including naturally occurring flavonoids and polyphenols as well as synthetic compounds, can block the formation of reactive oxygen and/or nitrogen species, and thus ultimately prevent the PTMs of many proteins with improved disease conditions. Therefore, the present review is aimed to describe the recent research developments in the molecular mechanisms for mitochondrial dysfunction and tissue injury in neurodegenerative diseases and discuss translational research opportunities.