Liver Proliferation Research Articles

OTUD4: A Potential Prognosis Biomarker for Multiple Human Cancers.

BackgroundDeubiquitinase OTU domain containing 4 (OTUD4) is initially identified as a K48-specific deubiquitinase and plays an important role in DNA damage repair signaling transduction. However, the expression level, prognostic role, biological function and mechanism of OTUD4 in multiple human cancers are unclear.MethodsGEPIA online (http://gepia.cancer-pku.cn/; The Cancer Genome Atlas (TCGA) database) was used to analyze the mRNA expression of OTUD4 in multiple human cancers. Kaplan-Meier plotter (KM plotter) database and TCGA database were used to evaluate the prognostic value of OTUD4 expression in multiple human cancers. MTT, Transwell and 3D culture assays were used to detect the role of OTUD4 in breast, liver and lung cancer cells. The correlation between OTUD4 and apoptosis signaling pathway and AKT signaling pathway was analyzed by Gene set enrichment analysis (GSEA).ResultsOTUD4 mRNA expression is significantly downregulated in multiple human cancer tissues. Survival analysis establishes that the downregulation of OTUD4 predicts poor prognosis in many solid tumors, including breast invasive carcinoma (BRCA), esophageal carcinoma (ESCA), liver hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD), and ovarian serous cystadenocarcinoma (OV). Furthermore, overexpression of OTUD4 could inhibit tumor cell proliferation, migration and invasion of breast, liver and lung cancer cells through inhibiting the AKT signaling pathway.ConclusionThis study found that OTUD4 may be a potential predictive factor for several human cancers and a tumor suppressor for breast, liver and lung cancer. The overexpression of OTUD4 restrained proliferation, migration and invasion of human breast, liver and lung cancer cells through promoting cancer cells apoptosis and inhibiting AKT signaling pathway. Notably, our results indicated that OTUD4 could be a useful biomarker for the prognosis of human cancers and a potential molecular target for diagnosis and treatment of breast, liver and lung cancer.

Hepatosplenic T Cell Lymphoma: A Rare Disease

Hepatosplenic T cell lymphoma (HSTCL) is an uncommon neoplasm comprising 5% of peripheral T-cell lymphomas. We report an uncommon case of Peripheral T-cell lymphoma that is characterized by primary extranodal disease with malignant T cell proliferation in spleen, liver and bone marrow. 19 year old male patient presented with fever, weakness and pain abdomen for 2 months. On clinical examination he was pale and had massive hepatosplenomegaly. The diagnosis was quite challenging as thorough clinical, hematological and immunophenotypic correlation was required.

Current status of associating liver partition and portal vein ligation for staged hepatectomy in treatment of liver metastasis of colorectal cancer

At present,radical resection remains the best treatment strategy for liver metastasis of colorectal cancer,and patients with large or multiple tumors often face the problem of insufficient residual liver volume after hepatectomy,which may lead to serious complications including liver failure after surgery. Associating liver partition and portal vein ligation for staged hepatectomy( ALPPS) is a novel two-step hepatectomy that allows rapid proliferation of the residual liver after primary surgery and can improve the resectability of liver tumors and reduce the risk of postoperative liver failure. Although ALPPS can achieve R0 resection or tumors and prolong patients' survival time,there are still controversies over its application due to high incidence rates of complications and mortality rate. With reference to related studies in China and foreign countries,this article reviews the current application status and clinical value of ALPPS in liver metastasis of colorectal cancer.

Participation of 5-lipoxygenase and LTB4 in liver regeneration after partial hepatectomy

Regeneration is the unmatched liver ability for recovering its functional mass after tissue lost. Leukotrienes (LT) are a family of eicosanoids with the capacity of signaling to promote proliferation. We analyzed the impact of blocking LT synthesis during liver regeneration after partial hepatectomy (PH). Male Wistar rats were subjected to two-third PH and treated with zileuton, a specific inhibitor of 5-lipoxygenase (5-LOX). Our first find was a significant increment of intrahepatic LTB4 during the first hour after PH together with an increase in 5-LOX expression. Zileuton reduced hepatic LTB4 levels at the moment of hepatectomy and also inhibited the increase in hepatic LTB4. This inhibition produced a delay in liver proliferation as seen by decreased PCNA and cyclin D1 nuclear expression 24 h post-PH. Results also showed that hepatic LTB4 diminution by zileuton was associated with a decrease in NF-ĸB activity. Additionally, decreased hepatic LTB4 levels by zileuton affected the recruitment of neutrophils and macrophages. Non-parenchymal cells (NPCs) from zileuton-treated PH-rats displayed higher apoptosis than NPCs from PH control rats. In conclusion, the present work provides evidences that 5-LOX activation and its product LTB4 are involved in the initial signaling events for liver regeneration after PH and the pharmacological inhibition of this enzyme can delay the initial time course of the phenomenon.

LncRNA RP11-422N16.3 Inhibits Cell Proliferation and EMT, and Induces Apoptosis in Hepatocellular Carcinoma Cells by Sponging miR-23b-3p.

ObjectiveThis study investigated the mechanism of RP11-422N16.3 sponging miR-23b-3p in cell proliferation, apoptosis and epithelial-mesenchymal transition (EMT) in liver cancer.MethodsExpressions of RP11-422N16.3, miR-23b-3p and dimethylglycine dehydrogenase (DMGDH) were determined in liver cancer tissues, adjacent normal tissues, hepatocellular carcinoma cell lines and normal liver epithelial cell line. Up-regulation of RP11-422N16.3 and down-regulation of miR-23b-3p were conducted in hepatocellular carcinoma cells. Bioinformatics analysis, luciferase reporter assay and RNA-pull down assay were performed to verify the relationship among miR-23b-3p, DMGDH, as well as RP11-422N16.3. Cell proliferation and cell apoptosis were determined by CCK-8 and Flow Cytometry analysis, respectively.ResultsExpressions of RP11-422N16.3 and DMGDH were down-regulated while that of miR-23b-3p were up-regulated in hepatocellular carcinoma cancer tissues and cells. RP11-422N16.3 localized in cytoplasm and competitively bound to miR-23b-3p. Up-regulation of RP11-422N16.3 and down-regulation of miR-23b-3p contributed to increased expressions of DMGDH and E-cadherin, and decreased expressions of miR-23b-3p, ZEB1, Snail and Vimentin, resulting in inhibiting cell proliferation and promoting cell apoptosis. Inhibition of RP11-422N16.3 or overexpression of miR-23b-3p accelerated cell proliferation and slowed down cell apoptosis. miR-23b-3p inhibited the expression of DMGDH.ConclusionOur data suggested that LncRNA RP11-422N16.3, by competitively binding to miR-23b-3p, promoted DMGDH expression, contributing to inhibit cell proliferation and EMT, and induce cell apoptosis in hepatocellular carcinoma cells.

Increased fatty acid oxidation and mitochondrial proliferation in liver are associated with increased plasma kynurenine metabolites and nicotinamide levels in normolipidemic and carnitine-depleted rats

Dysregulation of the tryptophan (Trp)-NAD+ pathway has been related to several pathological conditions, and the metabolites in this pathway are known to influence mitochondrial respiration and redox status. The aim of this project was to investigate if stimulation of beta-oxidation and mitochondrial proliferation by the mitochondrial-targeted compound 2-(tridec-12-yn-1-ylthio)acetic acid (1-triple TTA) would influence metabolites of the Trp-Kyn-NAD+ pathway. We wished to investigate how carnitine depletion by meldonium-treatment influenced these metabolites. After dietary treatment of male Wistar rats with 1-triple TTA for three weeks, increased hepatic mitochondrial- and peroxisomal fatty acid oxidation resulted. The plasma content of total carnitines decreased compared to control animals, whereas hepatic genes involved in CoA biosynthesis were upregulated by 1-triple TTA treatment. The plasma Trp level and individual metabolites in the kynurenine pathway were increased by 1-triple TTA, associated with decreased hepatic gene expression of indoleamine2,3-dioxygenase. 1-triple TTA treatment increased conversion of Trp to nicotinamide (Nam) as the plasma content of quinolinic acid, Nam and N1-methylnicotinamide (mNam) increased, accompanied with suppression of hepatic gene expression of α-amino-α-carboxymuconate-ε-semialdehyde decarboxylase. A positive correlation between mitochondrial fatty acid oxidation and Trp-derivatives was found. Almost identical results were obtained by 1-triple TTA in the presence of meldonium, which alone exerted minor effects. Moreover, the plasma Kyn:Trp ratio (KTR) correlated negatively to mitochondrial function. Whether increased flux through the Trp-NAD+ pathway increased redox status and lowered inflammation locally and systemically should be considered.

Transcriptional analysis and differentially expressed gene screening of spontaneous liver tumors in CBA/CaJ mice

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide due to its frequent metastasis, tumor recurrence, and lack of curative treatment. However, the underlying molecular mechanisms involved in HCC progression remain unclear. Here, we analyzed the global gene expression of spontaneous liver tumor tissue from CBA/CaJ mice by RNA-Seq and identified 10,706 and 10,374 genes in the normal and liver tumor groups, respectively. Only 9793 genes were expressed in both, 913 genes were identified in only the liver tumor group, and 581 genes were found in normal liver tissues. There were 2054 differentially expressed genes (DEGs), with 975 down-regulated genes and 1079 up-regulated genes. Gene ontology (GO) term enrichment analysis showed that 43 up-regulated genes were significantly associated with cell cycle regulation and hundreds of up-regulated genes were related to cell migration, adhesion, or metabolic processes. KEGG pathway enrichment also demonstrated that some DEGs were tightly associated with the cell cycle, extracellular matrix (ECM)-receptor interactions, as well as protein digestion and absorption pathways, indicating that the activation of these oncogenic cascades was closely related to tumor liver progression in CBA/CaJ mice. Ninety-three genes with elevated expression levels preferentially localized in microtubules, kinetochores, and spindles play an important role during mitosis and meiosis and are associated with the reorganization of the cytoskeleton in cancer cells during migration and invasion. Some ECM-related genes were significantly different in the tumor group, including collagen types I, III, IV, V, and VI, non-collagenous glycoproteins, laminin, and fibronectin. We further validated the functions of upregulated genes, such as cyclin-dependent kinase 1 (CDK1) and polo-like kinase 1 (PLK1), with regards to cell cycle regulation, apoptosis, and proliferation in normal human liver or liver tumor-derived cell lines. Our results indicated that the cell cycle dysregulation, ECM-receptor interaction, and cytoskeleton-associated genes in mouse livers may promote HCC progression and deciphering the function of the genes will help investigators understand the underlying molecular mechanism of HCC.

Phenolic Profile and In Vivo Cytotoxic Activity of Rice Straw Extract

Background: Previous work of our team exhibited that rice straw (RS) has antitumor activity in vitro and inhibit proliferation of liver, lung, prostate, and breast cancer human cell lines. In this work, we extended our research to screen the antitumor activity of RS ethanol extract as a single treatment and in the presence of combined radiotherapy with a low dose of gamma radiation against murine Ehrlich solid carcinoma (EAC) model. Objective: To evaluate the most common waste in Egypt RS to screen out its in vivo cytotoxic activity and as combined therapy with radiotherapy. Method: Tested sample RS was investigated for its content of phenolics by LC/MS/MS, in addition, ethanolic extracts of the tested sample were investigated as antitumor on female mice inoculated with EAC cells as a single treatment and in the presence of combined radiotherapy with a low dose of gamma radiation (LDR). Results: LC/MS/MS revealed that rice straw was rich in phenolic acids (vanillic, p-coumaric, ferulic, and sinapic acid) along with catechin and flavonoids aglycones (quercetin, apigenin, and kaempferol). Rice straw and/or exposure to a low dose of γ-radiation caused a marked suppression of tumor growth and induced significant reduction in VEGF level & in IL-6 level with significant elevation in IL-10 serum level. Rice straw caused a significant down regulation in the gene transcription level of MCL1 and b-catenin, and a significant up-regulation of Caspase-3 and Bax gene expression. RS extract and LDR (EC + RS + R group) revealed that there was a mild form of necrosis with severe apoptosis in the tumor cells. Conclusion: From the aforementioned results, it can be concluded that RS/LDR effectively and synergistically work towards inhibition of cancer cell proliferation. These findings were well supported with histopathological studies suggesting that RS/low dose gamma radiation can serve as a good therapeutic agent against cancer but still need further clinical studies.

PROLIFERATION, DNA DAMAGE RESPONSE AND HEMATOPOIETIC STEM CELL FUNCTION: A DYNAMIC, CONTEXT DEPENDENT RELATION

Proliferation in hematopoietic stem cells (HSCs) has been linked to stemness. A variety of mouse transgenic lines with increased HSC proliferation rates have shown concomitant deterioration of their function (Dev. Dyn. 2016). While some studies implicated DNA damage accumulation as the underlying reason (Walter D. et al. in Nature 2015), others have maintained that, in fact, quiescence of primitive HSCs might be the reason behind poor resolution of DNA damages (Mohrin M et al. in Cell Stem Cell 2010). In our earlier studies, we demonstrated that outside-in integrin signaling is important to maintain HSC quiescence (Khurana S. et al. in Nat. Comm. 2016). We showed loss of HSC function in mice deficient in interaction between Integrin-αv (Itgav; Vav-Itgav-/- mice) and its ligand Periostin (Postn; Postn-/- mice). Our recent studies show that increase in proliferation of fetal liver (FL) HSCs in these mice results in their efficient expansion without any loss of function. Postn deficient FL tissues showed clear increase in the frequency of primitive HSCs with long-term engraftment potential. They proliferated faster, without any functional decline. However, Vav-Itgav-/- FL HSCs transiting from proliferative to quiescent phenotype showed dependence on Itgav-Postn interaction for quiescence and functional integrity. On the basis of RNASeq based differential pathway analysis using BM and E14.5 FL derived HSCs, we hypothesized that better DNA damage response (DDR) pathways in FL derived HSCs could result in these observations. In deed we observed that HSCs derived from FL show better resistance to DNA damage than adult bone marrow. We went on to show the importance of integrin ligand Postn in the creation of hematopoietic niche in FL tissue. Overall, we propose through our results that proliferation in HSCs affects HSC function in developmental context dependent manner.

The Carcinogenic Agent Diethylnitrosamine Induces Early Oxidative Stress, Inflammation and Proliferation in Rat Liver, Stomach and Colon: Protective Effect of Ginger Extract.

Background:Diethylnitrosamine (DENA), a well-known dietary carcinogen, related to cancer initiation of various organs. The present study investigated the deleterious mechanisms involved in the early destructive changes of DENA in different organs namely, liver, stomach and colon and the potential protective effect of GE against these mechanisms. Methods:Adult male albino rats were assigned into four groups. A normal control group received the vehicle, another group was injected with a single necrogenic dose of DENA (200 mg/kg, i.p) on day 21. Two groups received oral GE (108 or 216 mg/kg) daily for 28 days. Sera, liver, stomach and colon were obtained 7 days after DENA injection. Serum aspartate transaminase and alanine transaminase were detected as well as reduced glutathione (GSH), malondialdehyde, nitric oxide metabolites, interleukin 1β, tumor necrosis factor (TNF-α), alpha-fetoprotein (AFP) and nuclear factor-erythroid 2-related factor2 (Nrf2) in liver, stomach and colon. Histopathological studies and immunohistochemical examination of cyclooxygenase-2 (COX2) were conducted.Results:DENA induced elevation in liver function enzymes with significant increase in oxidation and inflammation biomarkers and AFP while decreased levels of Nrf2 in liver, stomach and colon were detected. Histologically, DENA showed degenerative changes in hepatocytes and inflammatory foci. Inflammatory foci displayed increased expression of COX2 in immunohistochemical staining. GE-pretreatment improved liver function and restored normal GSH with significant mitigation of oxidative stress and inflammatory biomarkers compared to DENA-treated group. AFP was reduced by GE in both doses, while Nrf2 increased significantly. Histology and immunostaining of hepatic COX-2 were remarkably improved in GE-treated groups in a dose dependent manner. Conclusion:GE exerted a potential anti-proliferative activity against DENA in liver, stomach and colon via Nrf2 activation, whilst suppression of oxidation and inflammation.

Liver Proliferation Is an Essential Driver of Fibrosis in Mouse Models of Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) involves development of hepatic steatosis, fibrosis, and steatohepatitis. Because hepatic steatosis appears first in NAFLD animal models, the current therapy development focuses on inhibition of hepatic steatosis, suggesting that further steps of NAFLD will be also inhibited. In this report, we show that the first event of NAFLD is liver proliferation, which drives fibrosis in NAFLD. We have deleted a strong driver of liver proliferation, gankyrin (Gank), and examined development of NAFLD in this animal model under conditions of a high‐fat diet (HFD). We found that proliferating livers of wild‐type mice develop fibrosis; however, livers of Gank liver‐specific knockout (GLKO) mice with reduced proliferation show no fibrosis. Interestingly, an HFD causes the development of strong macrovesicular steatosis in GLKO mice and is surprisingly associated with improvements in animal health. We observed that key regulators of liver biology CCAAT/enhancer binding protein α (C/EBPα), hepatocyte nuclear factor 4α (HNF4α), p53, and CUG repeat binding protein 1 (CUGBP1) are elevated due to the deletion of Gank and that these proteins support liver functions leading to healthy conditions in GLKO mice under an HFD. To examine the role of one of these proteins in the protection of liver from fibrosis, we used CUGBP1‐S302A knockin mice, which have a reduction of CUGBP1 due to increased degradation of this mutant by Gank. These studies show that reduction of CUGBP1 inhibits steatosis and facilitates liver proliferation, leading to fibrosis and the development of liver tumors. Conclusion: Liver proliferation drives fibrosis, while steatosis might play a protective role. Therapy for NAFLD should include inhibition of proliferation rather than inhibition of steatosis.

Interferon gamma inhibits the differentiation of mouse adult liver and bone marrow hematopoietic stem cells by inhibiting the activation of notch signaling

BackgroundThe paradigm of hematopoietic stem and progenitor cells (HSPCs) has become accepted ever since the discovery of adult mouse liver hematopoietic stem cells and their multipotent characteristics that give rise to all blood cells. However, differences between bone marrow (BM) and liver hematopoietic stem cells and the hematopoietic microenvironment remain poorly understood. In addition, the regulation of the liver hematopoietic system remains unknown.MethodsClone formation assays were used to confirm that the proliferation of adult mouse liver and bone marrow HSPCs. Model mice with different interferon gamma (IFN-γ) levels and a co-culture system were used to detect the differentiation of liver HSPCs. The γ-secretase inhibitor (GSI) and the JAK/STAT inhibitor ruxolitinib and cell culture assays were used to explore the molecular mechanism by which IFN-γ impairs HSPC proliferation and differentiation.ResultsThe colony-forming activity of liver and bone marrow HSPCs was inhibited by IFN-γ. Model mice with different IFN-γ levels showed that the differentiation of liver HSPCs was impaired by IFN-γ. Using a co-culture system comprising liver HSPCs, we found that IFN-γ inhibited the development of liver hematopoietic stem cells into γδT cells. We then demonstrated that IFN-γ might impair liver HSPC differentiation by inhibiting the activation of the notch signaling via the JAK/STAT signaling pathway.ConclusionsIFN-γ inhibited the proliferation of liver-derived HSPCs. IFN-γ also impaired the differentiation of long-term hematopoietic stem cells (LT-HSCs) into short-term hematopoietic stem cells (ST-HSCs) and multipotent progenitors (MPPs) and the process from LSK (Lineage−Sca-1+c-Kit+) cells to γδT cells. Importantly, we proposed that IFN-γ might inhibit the activation of notch signaling through the JAK/STAT signaling pathway and thus impair the differentiation process of mouse adult liver and BM hematopoietic stem cells.

Hyaluronan-Based Grafting Strategies for Liver Stem Cell Therapy and Tracking Methods.

Cell adhesion is essential for survival, it plays important roles in physiological cell functions, and it is an innovative target in regenerative medicine. Among the molecular interactions and the pathways triggered during cell adhesion, the binding of cluster of differentiation 44 (CD44), a cell-surface glycoprotein involved in cell-cell interactions, to hyaluronic acid (HA), a major component of the extracellular matrix, is a crucial step. Cell therapy has emerged as a promising treatment for advanced liver diseases; however, so far, it has led to low cell engraftment and limited cell repopulation of the target tissue. Currently, different strategies are under investigation to improve cell grafting in the liver, including the use of organic and inorganic biomatrices that mimic the microenvironment of the extracellular matrix. Hyaluronans, major components of stem cell niches, are attractive candidates for coating stem cells since they improve viability, proliferation, and engraftment in damaged livers. In this review, we will discuss the new strategies that have been adopted to improve cell grafting and track cells after transplantation.

Combined kidney‑liver perfusion enhances the proliferation effects of hypothermic perfusion on liver grafts via upregulation of IL‑6/Stat3 signaling.

A limited number of studies have revealed that adding kidneys to liver perfusion may maintain an improved physiological balance; however, the underlying mechanism remains to be elucidated. The preset study confirmed the protective role of this new model and investigated the underlying mechanisms. Methods: A total of 12 rats were randomly assigned into two groups (n=6 for each group): The kidney-liver perfusion (KL) group and liver perfusion (LP) group. Perfusate samples were collected during the perfusion process for the analysis of pH, K+ and liver function. Liver tissues were obtained for the evaluation of adenosine triphosphate (ATP), terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling and immunohistochemistry of Ki67. Cell cycle inhibitors, apoptosis-associated genes and signal transducer and activator of transcription 3 (Stat3) were analyzed using quantitative polymerase chain reaction and western blot analysis. Results: Overall pH and K+ values of the KL group were significantly different from the LP group and more stable; aspartate aminotransferase, alanine transaminase and lactate dehydrogenase levels increased progressively over time in the LP group and were significantly different at different time points compared with pre-perfusion levels and the KL group, which suggested the KL group was superior to the LP group. In addition, KL reduced portal vein resistance and was associated with lower ATP consumption compared with the LP group. Furthermore, liver proliferation was upregulated with the upregulation of the interleukin 6 (IL-6)/Stat3 signaling pathway in KL compared with LP. The present study revealed for the first time that KL and hypothermic machine perfusion demonstrated a more proactive repair capability by maintaining liver regeneration via the upregulation of the IL-6/Stat3 signaling pathway.

Maternal undernutrition induces fetal hepatic lipid metabolism disorder and affects the development of fetal liver in a sheep model.

Undernutrition accelerates body fat mobilization to alleviate negative energy balance, which disrupts homeostasis of lipid metabolism in maternal liver. However, little is known about its effect on fetal metabolism and development. Here, a sheep model was used to explore whether maternal undernutrition induces fetal lipid metabolism disorder and further inhibits fetal hepatic development. Twenty pregnant ewes were either fed normally or restricted to 30% level for 15 d, after which fetal hepatic samples were collected to conduct transcriptome, metabolome, histomorphology, and biochemical analysis. Results showed that maternal undernutrition altered the general transcriptome profile and metabolic mode in fetal liver. Fatty acid oxidation and ketogenesis were enhanced in fetal livers of undernourished ewes, which might be promoted by the activated peroxisome proliferator-activated receptor α signaling pathway, whereas cholesterol, steroid, and fatty acid synthesis were repressed. Maternal undernutrition increased triglyceride synthesis, decreased triglyceride degradation, and inhibited phospholipid degradation and synthesis in fetal liver. In addition, our data revealed that maternal undernutrition extremely inhibited DNA replication, cell cycle progression, and antiapoptosis and broke the balance between cell proliferation and apoptosis in fetal liver, indicating that maternal undernutrition affects the growth and development of fetal liver. Generally, these findings provide evidence that maternal undernutrition during pregnancy disturbs fetal lipid metabolism and inhibits fetal hepatic development in sheep, which greatly contribute to the further study of fetal metabolism and development in human beings.-Xue, Y., Guo, C., Hu, F., Zhu, W., Mao, S. Maternal undernutrition induces fetal hepatic lipid metabolism disorder and affects the development of fetal liver in a sheep model.

Stilbene compound trans-3,4,5,4´-tetramethoxystilbene, a potential anticancer drug, regulates constitutive androstane receptor (Car) target genes, but does not possess proliferative activity in mouse liver

The constitutive androstane receptor(CAR) activation is connected with mitogenic effects leading to liver hyperplasia and tumorigenesis in rodents. CAR activators, including phenobarbital, are considered rodent non-genotoxic carcinogens. Recently, trans-3,4,5,4´-tetramethoxystilbene(TMS), a potential anticancer drug (DMU-212), have been shown to alleviate N-nitrosodiethylamine/phenobarbital-induced liver carcinogenesis. We studied whether TMS inhibits mouse Car to protect from the PB-induced tumorigenesis. Unexpectedly, we identified TMS as a murine CAR agonist in reporter gene experiments, in mouse hepatocytes, and in C57BL/6 mice in vivo. TMS up-regulated Car target genes Cyp2b10, Cyp2c29 and Cyp2c55 mRNAs, but down-regulated expression of genes involved in gluconeogenesis and lipogenesis. TMS did not change or down-regulate genes involved in liver proliferation or apoptosis such as Mki67, Foxm1, Myc, Mcl1, Pcna, Bcl2, or Mdm2, which were up-regulated by another Car ligand TCPOBOP. TMS did not increase liver weight and had no significant effect on Ki67 and Pcna labeling indices in mouse liver in vivo. In murine hepatic AML12 cells, we confirmed a Car-independent proapoptotic effect of TMS. We conclude that TMS is a Car ligand with limited effects on hepatocyte proliferation, likely due to promoting apoptosis in mouse hepatic cells, while controlling Car target genes involved in xenobiotic and endobiotic metabolism.

Diallyl disulfide attenuates non‑alcoholic steatohepatitis by suppressing key regulators of lipid metabolism, lipid peroxidation and inflammation in mice.

Non‑alcoholic steatohepatitis (NASH) is a common clinicopathological condition. Currently, the pathogenesis of NASH remains unknown, and no optimal therapy option currently exists. It has previously been demonstrated that diallyl disulfide (DADS) was capable of attenuating liver dysfunction, as DADS supplementation had a positive impact on liver regeneration, proliferation and oxidative damage. Thus, DADS could serve as a potential therapeutic agent that can protect against the effects of NASH. The present study aimed to evaluate the effect of DADS on NASH and to understand the associated underlying molecular mechanisms. A methionine‑ and choline‑deficient diet (MCD) and high‑fat diet (HFD) are the two common animal models that induce NASH. C57BL/6J mice were fed an MCD for 4weeks, or an HFD for 20weeks, in the present study. The mice were treated with or without DADS (20, 50 and 100mg/kg) for 4 or 20weeks. For the histopathological examination, hematoxylin and eosin staining, oil red O staining and immunohistochemical analyses were performed using the liver sections. Biochemical assays and ELISA were performed to measure the serum biochemical indicators of hepatic function and inflammatory indicators, respectively. Reverse transcription‑quantitative PCR, immunofluorescence and western blotting were used to detect expression levels of the genes involved in the molecular mechanisms underlying DADS protection. MCD or HFD induced the histological features of NASH in mice, including significant vacuolated hepatocytes, marked inflammatory cell infiltration and severe micro‑ and macro‑vesicular steatosis. Serum alanine transferase and aspartate aminotransferase levels, as well as the contents of liver triglyceride and total cholesterol, were significantly increased in these two models. DADS attenuated these histological and biochemical changes. DADS ameliorated hepatic steatosis by regulating sterol regulatory element‑binding transcription factor 1, apolipoprotein A1, cyclic AMP‑responsive element‑binding protein H and fibroblast growth factor 21. Furthermore, DADS was revealed to prevent lipotoxicity via peroxisome proliferator‑activated receptor α elevation and stearoyl‑coenzyme A desaturase1 inhibition in HFD‑fed mice. In addition, DADS markedly inhibited lipid peroxidation by modulating malondialdehyde and superoxide dismutase, and it also decreased tumor necrosis factor‑α production, interleukin‑6 production and macrophage influx, as well as suppressing nuclear factor‑κB activation, indicating suppression of MCD‑induced hepatic inflammation. Taken together, the results have shown that DADS exerts beneficial effects on MCD‑ or HFD‑induced NASH by suppressing key regulators of lipid metabolism, lipid peroxidation and inflammation.

Hepatic ZIP8‐mediated selenium transport contributes to normal liver function

ZIP8 is a multi‐functional electroneutral membrane transporter with substrates including both essential and toxic divalent metals (e.g. zinc, manganese, iron and cadmium) and micronutrient selenite. Despite that ZIP8 is found to be associated with metabolic disorders by GWAS, the physiological and pathological roles of ZIP8 remain to be characterized and its connection to any metabolic pathways has not been identified. Our preliminary results demonstrate that moderate or acute decreases in ZIP8 activity resulted in hepatic pathology. Chronic moderate ZIP8 deficiency in transgenic mice led to spontaneous liver neoplastic nodules with increased oxidative stress, inflammation and fibrosis. And acute ZIP8 decrease in mice via adenovirus induced significant hepatomegaly, injury, inflammation and proliferation in liver. In addition, we found that elevation of ZIP8 induced significant glycogen accumulation while downregulation of ZIP8 decreases the glycogen level in primary hepatocytes and liver. Along with these liver pathology, the selenium level and selenoproteins (including GPX1 and GPX2) significantly decreased after ZIP8 deficiency. Thus ZIP8 plays an important role in maintaining normal hepatic function, likely through regulating selenium homeostasis.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Gypenoside L Inhibits Proliferation of Liver and Esophageal Cancer Cells by Inducing Senescence.

Senescence is an irreversible state of cell cycle arrest that can be triggered by multiple stimuli, such as oxygen reactive species and DNA damage. Growing evidence has proven that senescence is a tumor-suppressive approach in cancer treatment. Therefore, developing novel agents that modulate senescence may be an alternative strategy against cancer. In our study, we investigated the inhibitory effect of gypenoside L (Gyp-L), a saponin isolated from Gynostemma pentaphyllum, on cancer cell growth. We found that Gyp-L increased the SA-β-galactosidase activity, promoted the production of senescence-associated secretory cytokines, and inhibited cell proliferation of human liver and esophageal cancer cells. Moreover, Gyp-L caused cell cycle arrest at S phase, and activated senescence-related cell cycle inhibitor proteins (p21 and p27) and their upstream regulators. In addition, Gyp-L activated p38 and ERK MAPK pathways and NF-κB pathway to induce senescence. Consistently, adding chemical inhibitors efficiently counteracted the Gyp-L-mediated senescence, growth inhibition, and cell cycle arrest in cancer cells. Furthermore, treatment with Gyp-L, enhanced the cytotoxicity of clinic therapeutic drugs, including 5-fluorouracil and cisplatin, on cancer cells. Overall, these results indicate that Gyp-L inhibits proliferation of cancer cells by inducing senescence and renders cancer cells more sensitive to chemotherapy.

Suppressed hepatocyte proliferation via a ROS-HNE-P21 pathway is associated with nicotine- and cotinine-enhanced alcoholic fatty liver in mice

CYP2A5 is a major enzyme responsible for nicotine and cotinine metabolism in mice. Nicotine and cotinine enhance alcoholic fatty liver in wild type (WT) mice but not in CYP2A5 knockout (KO) mice, and reactive oxygen species (ROS) generated during the CYP2A5-mediated metabolism contributes to the enhancing effect. In combination with ethanol, nicotine and cotinine increased lipid peroxidation end product 4-hydroxynonenal (HNE) in WT mice but not in KO mice. In ethanol-fed KO mice, only 5 and 10 genes were regulated by nicotine and cotinine, respectively. However, in ethanol-fed WT mice, 59 and 104 genes were regulated by nicotine and cotinine, respectively, and 7 genes were up-regulated by both nicotine and cotinine. Plin 2 and Cdkn1a are among the 7 genes. Plin2 encodes adipose differentiation-related protein (ADRP), a lipid droplet-associated protein, which was confirmed to be increased by nicotine and cotinine in WT mice but not in KO mice. Cdkn1a encodes P21 and elevated P21 in nuclei was also confirmed. HNE can increase P21 and P21 inhibit cell proliferation. Consistently, hepatocyte proliferation markers proliferating cell nuclear antigen (PCNA) and Ki67 were decreased in WT mice but not in KO mice by nicotine/ethanol and cotinine/ethanol, respectively. These results suggest that inhibition of liver proliferation via a ROS-HNE-P21 pathway is involved in nicotine- and cotinine-enhanced alcoholic fatty liver.