Ethanol sensitizes hepatocytes for TGF-β-triggered apoptosis

Effect of Europinidin against Alcohol-Induced Liver Damage in Rats by Inhibiting the TNF-α/TGF-β/IFN-γ/NF-kB/Caspase-3 Signaling Pathway

BACKGROUND

The effect of europinidin on alcoholic liver damage in rats was examined in this research.

METHODS

A total of 24 Wistar rats were grouped in the same way into four groups: normal control (normal), ethanol control (EtOH), europinidin low dose (10 mg/kg), and europinidin higher dose (20 mg/kg). The test group rats were orally treated with europinidin-10 and europinidin-20 for 4 weeks, whereas 5 mL/kg distilled water was administered to control rats. In addition, 1 h after the last dose of the above-mentioned oral treatment, 5 mL/kg (i.p.) EtOH was injected to induce liver injury. After 5 h of EtOH treatment, samples of blood were withdrawn for biochemical estimations.

RESULTS

Administration of europinidin at both doses restored all of the estimated serum, i.e., liver function tests (ALT, AST, ALP), biochemical test (Creatinine, albumin, BUN, direct bilirubin, and LDH), lipid assessment (TC and TG), endogenous antioxidants (GSH-Px, SOD, and CAT), malondialdehyde (MDA), nitric oxide (NO), cytokines (TGF-β, TNF-α, IL-1β, IL-6, IFN-γ, and IL-12), caspase-3, and nuclear factor kappa B (NF-κB) associated with the EtOH group.

CONCLUSION

The results of the investigation showed that europinidin had favorable effects in rats given EtOH and may have hepatoprotective potential property.

Alcohol-induced increase in BMP levels promotes fatty liver disease in male prediabetic stage Otsuka Long-Evans Tokushima Fatty rats

Alcohol consumption exacerbates liver abnormalities in animal models, but whether it increases the severity of liver disease in early diabetic or prediabetic rats is unclear. To investigate the molecular mechanisms underlying alcohol-induced liver steatosis or hepatitis, we used a prediabetic animal model. Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Fatty (LETO) rats were pair-fed with an ethanol-containing liquid diet for 6 weeks. Compared with controls, OLETF and LETO rats displayed more pronounced liver steatosis and higher plasma levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamate pyruvate transaminase (SPGT), indicating liver injury. Ethanol-fed LETO (Pd-L-E) rats showed mild liver steatosis and no inflammation compared with ethanol-fed OLETF (Pd-O-E) rats. Although precursor and active SREBP-1 levels in the liver of ethanol-fed OLETF rats significantly increased compared with control diet-fed OLETF rats (Pd-O-C), those of Pd-L-E rats did not. Bone morphogenetic protein (BMP) and TGF-β1 balance in Pd-O-E rats was significantly altered because BMP signaling was upregulated by inducing BMP2, BMP4, BMP7, BMP9, Smad1, and Smad4, whereas TGF-β1, Smad3, and Erk were downregulated. Activation of TGF-β/Smad signaling inhibited BMP2 and BMP9 expression and increased epithelial-mesenchymal transition (EMT) marker levels (Hepcidin, Snail, and Twist) in the liver of LETO rats. Livers of ethanol-fed OLETF rats showed increased levels of vimentin, FSP-1, α-SMA, MMP1, MMP13, and collagen III compared with rats of other groups, whereas EMT marker levels did not change. Thus, BMP exerted anti- and/or pro-fibrotic effects in ethanol-fed rats. Therefore, BMP and TGF-β, two key members of the TGF-β superfamily, play important but diverse roles in liver steatosis in young LETO and OLETF rats.

Maternal Ethanol Exposure-Induced Cardiac Fibrosis is Associated with Changes in TGF-β and SIRT1/FOXO3a Signaling in Male Rat Offspring: A Three-Month Follow-up Study

Ethanol exposure during pregnancy induces cardiac fibrosis in the fetal heart. However, the mechanisms by which consumption of ethanol induces fibrotic changes are not known. Pregnant rats were received ethanol 4.5 g/kg BW once per day from the 7th day of pregnancy (GD7) throughout lactation. Our findings demonstrated that, area of fibrosis increased in cardiac tissue in the pups on both postnatal day twenty one (PN21) and postnatal day ninety (PN90) after prenatal and early postnatal period ethanol treatment compared with the controls. It was accompanied by a decline in the expression of SIRT1 protein along with the elevation of FOXO3a and TGF-β protein expressions which were determined by western blot. Overall, our data reveal that prenatal alcohol usage increase in fibrotic regions in the pup hearts possibly by regulating TGF-β, FOXO3a and SIRT1 protein levels. These are potential therapeutic molecular targets that can be modulated to protect heart against maternal ethanol exposure.

Downmodulation of Regulatory T Cells Producing TGF-β Participates in Pathogenesis of Leprosy Reactions

Leprosy reactions are an acute and systemic manifestation, which occurs suddenly, can be severe and lead leprosy patients to disability. Reactional episodes are observed among half of the multibacillary patients, mainly in borderline lepromatous and lepromatous forms. They may begin at any time during multidrug therapy, and even before the treatment. Physical disabilities, which are the source of extreme suffering and pain for patients, occur in progression of the cellular immune response associated with a reaction and are still poorly understood. Thus, this work aimed to phenotypically and functionally characterize CD4⁺ and CD8⁺ Treg cells ex vivo and in response to Mycobacterium leprae (ML). We studied 52 individuals, including 18 newly diagnosed and untreated multibacillary leprosy patients, 19 reactional multibacillary patients (Type I or Type II episodes) and 15 healthy volunteers, included as controls, all residents of the city of Rio de Janeiro. The functional activity and frequencies of these cells were evaluated through multiparametric flow cytometry. In addition, the production of cytokines in supernatant from peripheral blood mononuclear cell cultures was also investigated against ML by enzyme-linked immunosorbent assay. Our results showed a decrease in CD4⁺TGF-β⁺ Treg and CD8⁺ TGF-β⁺ Treg in leprosy multibacillary patients during both types of reactional episodes. Alterations in the cytokine profile was also observed in Type II reactions, along with upregulation of IL-17 and IL-6 in supernatant. Thus, our study suggests that downregulation of Treg cells is related with both classes of reactional episodes, improving our understanding of immune hyporesponsiveness in multibacillary patients and hyperesponsiveness in both reactions.

Chronic Alcohol Exposure Among People Living with HIV Is Associated with Innate Immune Activation and Alterations in Monocyte Phenotype and Plasma Cytokine Profile

Despite advances in antiretroviral therapy, chronic immune activation continues to be observed among individuals with well-controlled HIV viral loads, and is associated with non-AIDS defining morbidities among people living with HIV. Alcohol use disorder impacts a significant proportion of individuals living with HIV, and alcohol exposure is known to damage the intestinal epithelium which may increase translocation of pathogens and their molecular products, driving systemic immune activation and dysregulation. The aim of this study was to determine if adults living with HIV with well-controlled viral loads, who also suffer from alcohol use disorder with and without hepatitis C virus co-infection (n=23), exhibit evidence of advanced systemic immune activation, intestinal damage, and microbial translocation, as compared to adults living with HIV who are not exposed to chronic alcohol or other substances of abuse (n=29). The impact of a 1-month intervention to treat alcohol-use disorder was also examined. Alcohol-use disorder was associated with evidence of advanced innate immune activation, alterations in monocyte phenotype including increased expression of Toll-like receptor 4, increased burden of stimulatory ligands for Toll-like receptor 4, and alterations in plasma cytokine signature, most notably elevations in soluble CD40 ligand and transforming growth factor beta. Alcohol-associated immune activation was more pronounced among individuals with hepatitis C virus co-infection. Although the 1-month intervention to treat alcohol use disorder did not result in significant reductions in the interrogated indicators of immune activation, our findings suggest that chronic alcohol exposure is a major modifiable risk factor for chronic immune activation and dysregulation among people-living with HIV.

Withaferin A alleviates ethanol-induced liver injury by inhibiting hepatic lipogenesis

Withaferin A (WA) is a natural steroidal compound with reported hepatoprotective activities against various liver diseases. Whether WA has therapeutic effects on alcoholic liver disease has not been explored. A binge alcoholic liver injury model was employed by feeding C57BL/6J mice an ethanol (EtOH) diet for 10 days followed by an acute dose of EtOH to mimic clinical acute-upon-chronic liver injury. In this binge model, WA significantly reduced the binge EtOH-induced increase of serum aminotransaminase levels and decreased hepatic lipid accumulation. Mechanistically, WA decreased levels of hepatic lipogenesis gene mRNAs in vivo, including Srebp1c, Fasn, Acc1 and Fabp1. In EtOH-treated primary hepatocytes in vitro, WA decreased lipid accumulation by lowering the expression of the lipogenesis gene mRNAs Fasn and Acc1 as well as decreasing hepatocyte death. In the established binge alcoholic liver injury model, WA therapeutically reduced the EtOH-induced increase of serum aminotransaminase levels as well as hepatic lipid accumulation. These results demonstrate that WA reduces EtOH-induced liver injury by inhibiting hepatic lipogenesis, suggesting a potential therapeutic option for treating alcoholic liver injury.

Interleukin-9 attenuates inflammatory response and hepatocyte apoptosis in alcoholic liver injury

Alcoholic liver injury is a liver cell dysfunction disease caused by long-term or excessive alcohol consumption. Inhibiting the production of inflammatory factors is an important way to alleviate liver injury. Interleukin-9 (IL-9) is one of the members of IL-2Rγc family. It has multiple biological functions. Previous studies have shown that IL-9 is a cytokine that is closely related to inflammatory disease, allergic diseases, autoimmune diseases, and parasitic infections. However, no systematic studies have been performed to address the role of IL-9 in ALI. This project aims to investigate the effects of IL-9 on macrophage-related inflammatory response and hepatocyte apoptosis in alcohol-induced liver injury by injecting adeno-associated virus (AAV9) into tail vein. In the ALI model group, western blot and ELISA assays demonstrated that the expression of IL-9 was reduced. Overexpression of IL-9 relieved the injury and reduced the serum levels of IL-6, TNF-α in EtOH-induced ALI mouse model. Moreover, by using western blot, it was indicated that IL-9 can inhibit the expression of pro-apoptotic protein, such as cleaved caspase 3 and Bax. In vitro, mouse recombinant protein IL-9 inhibited the expression of IL-6, TNF-α in EtOH-induced RAW264.7 cells. Moreover, flow cytometry and western blot results displayed that macrophage-derived IL-9 inhibited hepatocyte apoptosis. After silencing STAT3 in AML-12 cells, the anti-apoptotic effect of macrophage-derived IL-9 was further enhanced. These results indicate that IL-9 reduces the production of pro-inflammatory factors in ALI. Furthermore, macrophage-derived IL-9 can reduce hepatocyte apoptosis by inhibiting the activation of the STAT3 pathway.

Drug Repurposing in Alternative Medicine: Sochehwan, a Polyherbal Traditional Korean Digestant, Protects against Alcoholic Steatohepatitis by Regulating Cytochrome P450 2E1 Expression

Sochehwan (SCH) is an herbal prescription from traditional oriental medicine and is currently used to treat digestive ailments. In a previous study, SCH was found to have the potential to attenuate metabolic syndrome (MetS) by activating AMPK and downstream signaling. From the view of drug repurposing, the efficacy of SCH on alcoholic liver injury is implied in classic medical texts but is yet to be proven. C57BL/6J mice were pre-treated with SCH orally for 5 days and challenged by providing a pair-fed Lieber DeCarli diet containing alcohol for 20 days. Hepatic enzyme and triglyceride levels and endoplasmic reticulum (ER) stress-related markers were analyzed. Moreover, mitogen-activated protein kinases (MAPKs) and cytochrome P450 2E1 (CYP2E1) levels were determined. CYP2E1-transfected HepG2 cells were used to test the cytoprotective efficacy of SCH against the adverse effects of alcohol in vitro. In mice, SCH administration notably reduced hepatic enzyme activity and neural lipid levels. Furthermore, ER-stress markers and MAPK phosphorylation were reduced due to ROS suppression, which was attributed to decreased CYP2E1 expression in liver tissue. In addition, SCH successfully protected CYP2E1-transfected HepG2 cells against ethanol. Our findings suggest SCH attenuated alcohol-induced liver injury by inhibiting CYP2E1 expression and indicate drug repurposing should be considered as a valuable option for drug development in traditional herbal medicines.

Mangosteen Hinders Gamma Radiation-Mediated Oxidative Stress and Liver Injury by Down-Regulating TNF-α/NF-κB and Pro-Fibrotic Factor TGF-β1 Inducing Inflammatory Signaling

Background:

Liver injury due to ionizing radiation exposure either accidental or after radiotherapy treatment, may lead to many alterations in proteins expression related to inflammation or apoptosis. Our study investigated the curative effect of Mangosteen (MGS) extract (fruit rind) against ionizing radiation (IR) induced liver damage.

Methods:

Hepatotoxicity was induced in Wister rats by exposure to an acute single dose (6 Gy) of IR while MGS was given orally to rats (500 mg/kg bwt) and administered daily for 30 days after irradiation.

Results:

MGS treatment has significantly attenuated redox imbalance state and toxicity induced by protracted exposure to gamma-rays in liver tissues, which was substantiated by the significant amelioration of liver function tests, MDA contents, antioxidant enzymes (SOD and CAT) activities and NO level. MGS inhibited also the inflammatory markers (TNF-alpha, IL-6 and CRP) and downregulated transcriptional factor NF-Kappa-B/TGF-β1. These alterations were concomitant with an improvement of the Proliferating cell nuclear antigen (PCNA) which is a protein expressed in the nuclei of cells during cell cycle and is important for both DNA synthesis and DNA repair. These results were confirmed by amelioration in histological and ultrastructural examinations.

Conclusion:

We concluded that MGS could ameliorate via minimizing significantly the amount of oxidative damage, inflammations disturbances and pro-apoptotic alternations induced by IR. MGS may be a promising supplement with protective effects from irradiation-induced injury such as TNF-α/NF-κB/TGF-β1 management.

Gut microbiota and their metabolites in the progression of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disorder worldwide. It comprises a spectrum of conditions that range from steatosis to non-alcoholic steatohepatitis, with progression to cirrhosis and hepatocellular carcinoma. Currently, there is no FDA-approved pharmacological treatment for NAFLD. The pathogenesis of NAFLD involves genetic and environmental/host factors, including those that cause changes in intestinal microbiota and their metabolites. In this review, we discuss recent findings on the relationship(s) of microbiota signature with severity of NAFLD and the role(s) microbial metabolites in NAFLD progression. We discuss how metabolites may affect NAFLD progression and their potential to serve as biomarkers for NAFLD diagnosis or therapeutic targets for disease management.

Functional Food XingJiuTang Attenuates Alcohol-Induced Liver Injury by Regulating SIRT1/Nrf-2 Signaling Pathway

Lipid accumulation, inflammatory responses and oxidative stress have been implicated in the pathology of alcohol-induced liver injury (ALI). In this work, we evaluated the effects of the functional food XingJiuTang (XJT) on ALI and explored the underlying mechanism. We used alcohol-stimulated human normal hepatocytes L02 for in vitro experiments, while for in vivo experiments, 55 % alcohol was intragastrically administrated to C57BL/6 mice at 16 mL/kg with pre-administration of bifendate and XJT. Liver histology and function, along with the inflammatory cytokines, oxidative mediators and SIRT1/Nrf-2 pathway were evaluated. The results showed that XJT treatment significantly alleviated ALI, ameliorated lipid peroxidation, improved the liver function impaired by alcohol and inhibited the hepatocytes apoptosis in vitro and in vivo. In addition, XJT treatment modulated the activation of the SIRT1/Nrf-2 signaling pathway and suppressed the overexpression of NOX4. Overall, the functional food XJT effectively protects against experimental ALI via activating the SIRT1/Nrf-2 pathway.

Pathophysiology of hepatic Na+/H+ exchange (Review)

Na+/H+ exchangers (NHEs) are a family of membrane proteins that contribute to exchanging one intracellular proton for one extracellular sodium. The family of NHEs consists of nine known members, NHE1-9. Each isoform represents a different gene product that has unique tissue expression, membrane localization, physiological effects, pathological regulation and sensitivity to drug inhibitors. NHE1 was the first to be discovered and is often referred to as the 'housekeeping' isoform of the NHE family. NHEs are not only involved in a variety of physiological processes, including the control of transepithelial Na+ absorption, intracellular pH, cell volume, cell proliferation, migration and apoptosis, but also modulate complex pathological events. Currently, the vast majority of review articles have focused on the role of members of the NHE family in inflammatory bowel disease, intestinal infectious diarrhea and digestive system tumorigenesis, but only a few reviews have discussed the role of NHEs in liver disease. Therefore, the present review described the basic biology of NHEs and highlighted their physiological and pathological effects in the liver.

TGF-β1 alleviates HgCl2 induced apoptosis via P38 MAPK signaling pathway in human trophoblast cells

It is well known that embryonic development can be perturbed by environmental factors such as heavy metals. Mercury is one of the most significant threats to the environment and human health. Mercury can damage many parts of the human body, including lungs, kidneys, nerves and fetus. However, the effect of mercury on human embryo remains unknown. Here, we showed that HgCl₂ treatment resulted in a significant increase in apoptosis in HTR-8/SVneo cells. However, the effect of HgCl₂ on apoptosis was partially reduced by the combination treatment with TGF-β1 and HgCl₂ in HTR-8/SVneo cells. Moreover, HgCl₂ treatment gradually decreased the expression of TGF-β1 in a dose dependent manner. Furthermore, a P38 MAPK inhibitor, SB202190, decreased the cell apoptosis and caspase activation induced by HgCl₂ in trophoblast cells. In addition, TGF-β1 alleviated HgCl₂ induced apoptosis of HTR-8/SVneo cells via p38 MAPK signaling pathway, which was involved in the TAK1 expression. These results might provide a theoretical basis for mercury induced trophoblast associated embryo damage and a potential avenue of intervention.

Berberine inhibits epithelial-mesenchymal transition and promotes apoptosis of tumour-associated fibroblast-induced colonic epithelial cells through regulation of TGF-β signalling

Tumour-associated fibroblasts (TAFs) mediate the differentiation of adjacent stromal cells. Berberine (BBR), a monomer of traditional Chinese herbs, exhibits a potent therapeutic effect against cancer. However, the effects of BBR on the differentiation of normal colonic epithelial cells induced by TAFs have not been determined. In the present study, we selected the TAF-like myofibroblast cell line CCD-18Co. CCD-18Co-derived conditioned medium (CM) and co-culture induced epithelial-mesenchymal transition (EMT) changes in colonic epithelial HCoEpiC cells with decreased E-cadherin and increased vimentin and α-SMA expression. In addition, CCD-18Co stimulated the expression of ZEB1 and Snail and promoted motility. We used LY364947, a TGF-β receptor kinase type I (TβRI) inhibitor, and BBR. Our results showed that LY364947 and BBR inhibited these phenomena. BBR decreased the expression of ZEB1 and Snail, and this effect was concentration dependent. BBR also downregulated the expression of TβRI, TβRII, Smad2/p-Smad2 and Smad3/p-Smad3. In addition, BBR induced apoptosis in EMT-like HCoEpiC cells in a concentration-dependent manner with upregulation of Bax and downregulation of Bcl-2. However, VX-702, an inhibitor of p38 MAPK, significantly suppressed the apoptosis rate. BBR promoted the expression of p38 MAPK and phosphorylated p38 MAPK. In conclusion, berberine inhibits EMT and promotes apoptosis in TAF-induced colonic epithelial cells through mediation of the Smad-dependent and SMAD-independent TGF-β signalling pathways.

Hepatoprotective activity of metformin: A new mission for an old drug?

Metformin, as a dimethyl biguanide prescribed as the first-line medication for treatment of type 2 diabetes mellitus, is one of the most frequently used drugs, worldwide. However, the beneficial effects of metformin are not limited to insulin sensitizing and blood glucose lowering effects as recent clinical trials deciphered lower cancer risk in metformin users. In addition, metformin protected the liver against chemical or viral hepatotoxicants through various mechanisms including activation of AMPK via inhibition of mitochondrial complex I, inhibition of mitogen activated protein kinase (MAPK) and inhibition of Smads phosphorylation. Clinical trials are under way to assess possible additive effects of metformin when co-administered along with the standard regimen for hepatocellular carcinoma (HCC) treatment. This review outlines the molecular mechanisms behind protective activity of metformin against different liver diseases.

Chemical induction of hepatic apoptosis in rodents

The urge of identifying new pharmacological interventions to prevent or attenuate liver injury is of critical importance and needs an expanded experimental toolbox. Hepatocyte injury and cellular death is a prominent feature behind the pathology of liver diseases. Several research activities focused on identifying chemicals and hepatotoxicants that induce cell death by apoptosis, in addition to presenting its corresponding signaling pathway. Although such efforts provided further understanding of the mechanisms of cell death, it has also raised confusion concerning identifying the involvement of several modes of cell death including apoptosis, necrosis and fibrosis. The current review highlights the ability of several chemicals and potential hepatotoxicants to induce liver damage in rodents by means of apoptosis while the probable involvement of other modes of cell death is also exposed. Thus, several chemical substances including hepatotoxins, mycotoxins, hyperglycemia inducers, metallic nanoparticles and immunosuppressant drugs are reviewed to explore the hepatic cytotoxic spectrum they could exert on hepatocytes of rodents. In addition, the current review address the mechanism by which hepatotoxicity is initiated in hepatocytes in different rodents aiding the researcher in choosing the right animal model for a better research outcome.