Modulation of IKKß/NF-κB and TGF-ß1/Smad via Fuzheng Huayu recipe involves in prevention of nutritional steatohepatitis and fibrosis in mice.

OBJECTIVES: Fuzheng Huayu recipe (FZHY) exerts significant protective effects against liver fibrosis by strengthening the body's resistance and removing blood stasis. However, the molecular mechanisms through which FZHY affects liver fibrosis are still unclear. In this study, we examined the expression levels of factors involved in the inhibitor κB kinase-ß (IKK-ß)/nuclear factor-κB (NF-κB) and transforming growth factor beta 1 (TGF-ß1)/Smad signaling pathways to elucidate whether FZHY could attenuate nutritional steatohepatitis and fibrosis in mice. MATERIALS AND METHODS: C57BL/6J mice were fed with methionine-choline deficient (MCD) diet for 8 weeks to induce fibrotic steatohepatitis. FZHY and/or heme oxygenase-1 (HO-1) chemical inducer (hemin) were administered to mice. The effects of FZHY alone and in combination with hemin were assessed by comparing the severity of hepatic injury, activation of hepatic stellate cells (HSCs), and the expression of oxidative stress, inflammation and fibrogenesis related genes. RESULTS: Administration of FZHY, hemin and FZHY plus hemin significantly ameliorated liver injury. Additionally, our analysis indicated that administration of these agents significantly attenuated oxidative stress, downregulated the expression of pro-inflammatory and pro-fibrotic genes, including IKK-ß, NF-κB, monocyte chemoattractant protein-1 (MCP-1), α-smooth muscle actin (α-SMA), TGF-ß1, Smad3 and Smad4, and upregulated the expression of the antifibrogenic gene Smad7 (P< 0.001). CONCLUSION: FZHY-containing therapies prevented nutritional steatohepatitis and fibrosis through modulating the expression of factors associated with the IKKß/NF-κB and TGF-ß1/Smad signaling pathways and oxidative stress related genes.

[Establishment of a complex alcoholic liver fibrosis mouse model and investigation of OPN and TGF-beta1 hepatic expression].

OBJECTIVE: To create a convenient method to establish an alcoholic liver fibrosis model in mice and use it to explore the putative pathogenic mechanisms involving the immunomodulatory proteins osteopontin (OPN) and transforming growth factor-betal (TGF-beta1). METHODS: Forty C57BLI6J mice were fed the Lieber-DeCarli 4% ethanol-containing liquid diet for four weeks, followed by an additional four weeks of the 4% ethanol diet combined with intraperitoneal injection of carbon tetrachloride (CC14 5% solution in olive oil; 2ml/ kg body weight, 2 times/week) to induce alcoholic liver fibrosis. Control groups (n = 6 each) included: normal diet; normal diet plus CCl4 injections; ethanol diet alone; ethanol diet plus solvent (olive oil) injections. Model establishment was monitored by sacrificing six mice at model inception (week 0), and weeks 4, 5, 6, 7, and 8 of modeling to collect liver tissues and blood for histological and biochemical analyses. Extent of hepatic steatosis, inflammation, and fibrosis was assessed by hematoxylin-eosin and Masson staining. Liver function markers, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, were tested by automated enzymatic assays. Alpha-smooth muscle actin (alpha-SMA) expression was detected by immunohistochemistry. The mRNA and protein expression of OPN and TGF-beta1 was detected by real-time quantitative reverse transcription-PCR and western blotting, respectively. Significance of differences between multiple groups was assessed by one-way ANOVA analysis followed by least significant difference t-test or Kruskal-Wallis H test followed by the Mann-Whitney U test. RESULTS: Compared to the control groups, the group of mice administrated ethanol and CCl4 developed mild to moderate hepatic steatosis at week 4 of modeling, progressive necroinflammation and perisinusoidal and portal fibrosis from weeks 5-8, and irregular necrosis and bridging fibrosis at week 8. In addition, the model group showed progressive up-regulation of a-SMA expression in the activated hepatic stellate cells (HSCs) and fibrotic areas from weeks 5-8. Both hepatic OPN and TGF-beta1 showed significantly increasing trends in mRNA and protein expressions from weeks 5-8 (OPN mRNA: 1.83 +/- 0.25, 2.94 +/- 0.19, 3.45 +/- 0.31, and 5.99 +/- 0.17 (F= 476.27, P < 0.001); OPN protein: 0.52 +/- 0.06, 1.02 +/- 0.10, 1.52 +/- 0.11 and 1.50 +/- 0.08 (F= 298.03, P< 0.001); TGF-beta1 mRNA: 13.19 +/- 0.40, 3.31 +/- 0.28, 1.58 +/- 0.18 and 2.08 +/- 0.26 (F= 85.55, P < 0.001); TGF-P31 protein: 1.26 +/- 0.16, 0.96 +/- 0.12, 1.09 +/- 0.25 and 1.10 +/- 0.20 (F = 43.64, P < 0.001). CONCLUSION: Feeding C57BL/6J mice the Lieber-DeCarli ethanol-containing liquid diet combined with CCl4 intraperitoneal injection is a convenient method to establish a model of alcoholic liver fibrosis within a relatively short amount of time (eight weeks). Progression of alcoholic liver fibrosis is accompanied by increased hepatic expression of OPN and TGF-beta1, which may contribute to the pathogenic mechanism of this disease and may be targets of future molecular therapies.

[Activation of Fas/FasL and its downstream signaling pathway promotes development of alcoholic steatohepatitis and liver fibrosis in mice].

OBJECTIVE: To explore the role and mechanism of the Fas/Fas ligand (FasL) system and its downstream signaling pathway related to the progression of alcoholic steatohepatitis and liver fibrosis. METHODS: Eighteen C57BL/6J mice were randomly divided into three groups: controls; alcoholic steatohepatitis model, given four-weeks of a 4% ethanol-containing Lieber-DeCarli liquid diet; alcoholic steatohepatitis and liver fibrosis model, given the four-week alcohol diet followed by twice weekly intraperitoneal injections of carbon tetrachloride (5% olive oil solution; 2 mL/kg dose) during the fifth to eighth weeks. Mice in the model groups were sacrificed at the end of week 4 and 8, respectively, along with control mice for comparative analyses. Liver tissue sections were evaluated for hepatocellular apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. The mRNA expression of Fas, FasL, cysteine aspartate-specific proteases 3 (caspase 3), and cytochrome P450 2E1 (CYP 2E1) in liver tissues was detected by reverse transcription (RT)-PCR, visualized by ethidium bromide staining, and normalized to the gray-value of GAPDH expression. The protein expression of Fas and caspase 3 were detected by western blotting (b-actin normalized), and of FasL and CYP 2E1 by immunohistochemistry staining. Intergroup differences and statistical significance were evaluated by single factor analysis of variance and the least squares difference-t test or the Kruskal-Wallis H test and the Mann-Whitney U test. RESULTS: The number of apoptotic cells in the liver sections was significantly higher in both model groups with alcoholic steatohepatitis (vs. controls) and the amount in the alcoholic steatohepatitis plus liver fibrosis model was significantly higher than that in the model with only alcoholic steatohepatitis. In addition, activation of Fas, FasL and its downstream signaling pathway showed an increasing trend with extent of liver injury. The hepatic mRNA (by RT-PCR) and protein (by western blotting) normalized expression levels in the controls, alcoholic steatohepatitis models, and alcoholic steatohepatitis plus liver fibrosis models were, respectively: Fas mRNA: 0.50+/-0.05, 0.61+/-0.10, 0.76+/-0.03 (H=12.137, P less than 0.05), protein: 0.52+/-0.14, 0.86+/-0.10, 0.99+/-0.09 (F=12.758, P less than 0.01); FasL mRNA: 0.31+/-0.03, 0.53+/-0.02, 1.02+/-0.04 (F=153.260, P less than 0.01); caspase 3 mRNA: 0.86+/-0.11, 0.85+/-0.05, 1.33+/-0.16 (F=8.740, P less than 0.01), protein: 0.40+/-0.03, 0.69+/-0.06, 1.02+/-0.10 (F=90.785, P less than 0.01); CYP 2E1 mRNA: 0.72+/-0.14, 1.00+/-0.15, 1.30+/-0.20 (H=4.713, P less than 0.01). The changes in hepatic FasL and CYP 2E1 expression detected by immunohistochemistry were consistent with the mRNA expression. CONCLUSION: Activation of Fas/FasL and its downstream signaling pathway, which induces hepatocellular apoptosis, contributes to the development of alcoholic steatohepatitis and liver fibrosis.

Fuzheng Huayu recipe prevents nutritional fibrosing steatohepatitis in mice.

BACKGROUND: Fuzheng Huayu recipe (FZHY), a compound of Chinese herbal medicine, was reported to improve liver function and fibrosis in patients with hepatitis B virus infection. However, its effect on nutritional fibrosing steatohepatitis is unclear. We aimed to elucidate the role and molecular mechanism of FZHY on this disorder in mice. METHODS: C57BL/6 J mice were fed with methionine-choline deficient (MCD) diet for 8 weeks to induce fibrosing steatohepatitis. FZHY and/or heme oxygenase-1 (HO-1) chemical inducer (hemin) were administered to mice, respectively. The effect of FZHY was assessed by comparing the severity of hepatic injury, levels of hepatic lipid peroxides, activation of hepatic stellate cells (HSCs) and the expression of oxidative stress, inflammatory and fibrogenic related genes. RESULTS: Mice fed with MCD diet for 8 weeks showed severe hepatic injury including hepatic steatosis, necro-inflammation and fibrosis. Administration of FZHY or hemin significantly lowered serum levels of alanine aminotransferase, aspartate aminotransferase, reduced hepatic oxidative stress and ameliorated hepatic inflammation and fibrosis. An additive effect was observed in mice fed MCD supplemented with FZHY or/and hemin. These effects were associated with down-regulation of pro-oxidative stress gene cytochrome P450 2E1, up-regulation of anti-oxidative gene HO-1; suppression of pro-inflammation genes tumor necrosis factor alpha and interleukin-6; and inhibition of pro-fibrotic genes including α-smooth muscle actin, transforming growth factor beta 1, collagen type I (Col-1) and Col-3. CONCLUSIONS: Our study demonstrated the protective role of FZHY in ameliorating nutritional fibrosing steatohepatitis. The effect was mediated through regulating key genes related to oxidative stress, inflammation and fibrogenesis.

Higher plant antioxidants and redox signaling under environmental stresses.

Main antioxidants in higher plants include glutathione, ascorbate, tocopherol, proline, betaine, and others, which are also information-rich redox buffers and important redox signaling components that interact with biomembrane-related compartments. As an evolutionary consequence of aerobic life for higher plants, reactive oxygen species (ROS) are formed by partial reduction of molecular oxygen. The above enzymatic and non-enzymatic antioxidants in higher plants can protect their cells from oxidative damage by scavenging ROS. In addition to crucial roles in defense system and as enzyme cofactors, antioxidants influence higher plant growth and development by modifying processes from mitosis and cell elongation to senescence and death. Most importantly, they provide essential information on cellular redox state, and regulate gene expression associated with biotic and abiotic stress responses to optimize defense and survival. An overview of the literature is presented in terms of main antioxidants and redox signaling in plant cells. Special attention is given to ROS and ROS-antioxidant interaction as a metabolic interface for different types of signals derived from metabolism and from the changing environment, which regulates the appropriate induction of acclimation processes or, execution of cell death programs, which are the two essential directions for higher plants.