Resveratrol inhibits nonalcoholic fatty liver disease in rats

Es reproducción del documenteo publicado en http://dx.doi.org/10.1186/1471-230X-8-40Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) is high. NAFLD is linked to obesity, diabetes mellitus, and hypertriglyceridemia. Approximately 20% of patients with NAFLD will eventually develop cirrhosis. Our purpose was to investigate whether resveratrol decreased hepatic steatosis in an animal model of steatosis, and whether this therapeutic approach resulted in a decrease in tumor necrosis factor alpha (TNF-alpha) production, lipid peroxidation and oxidative stress. Methods: Male Wistar CRL: Wi (Han) (225 g) rats were randomized into three groups. A control group (n = 12) was given free access to regular dry rat chow for 4 weeks. The steatosis (n = 12) and resveratrol (n = 12) groups were given free access to feed (a high carbohydrate-fat free modified diet) and water 4 days per week, and fasted for the remaining 3 days for 4 weeks. Rats in the resveratrol group were given resveratrol 10 mg daily by the oral route. All rats were killed at 4 weeks and assessed for fatty infiltration and bacterial translocation. Levels of TNF-alpha in serum, hepatic malondialdehyde (MDA), oxidative stress (superoxide dismutase, glutathione peroxidase, catalase and nitric oxide synthase) and biochemical parameters were measured. Results: Fat deposition was decreased in the resveratrol group as compared to the steatosis group (Grade 1 vs Grade 3, P < 0.05). TNF-alpha and MDA levels were significantly increased in the steatosis group (TNF-alpha; 33.4 +/- 5.2 vs 26.24 +/- 3.47 pg/ml and MDA; 9.08 +/- 0.8 vs 3.17 +/- 1.45 mu M respectively, P < 0.05). This was accompanied by increased superoxide dismutase, glutathione peroxidase and catalase and decreased nitric oxide synthase in the liver of resveratrol group significantly (P < 0.05 vs steatosis group). Bacterial translocation was not found in any of the groups. Glucose levels were decreased in the group of rats given resveratrol (P < 0.05). Conclusion: Resveratrol decreased NAFLD severity in rats. This effect was mediated, at least in part, by TNF-alpha inhibition and antioxidant activities

Araztegi-lokatzak jasotako lurzoruaren analisi toxikologikoa zizare eta landareak erabiliz

Urtetik urtera areagotzen diren giza populazioak eta jarduera industrialak zabortegi, isuri-puntu eta betetze guneen emendioa eragin du. Zabortegi horien artean, 48046-00181 kodearekin, "17-zabortegia" dago, Gernika-Lumon kokatua (43°19’28,9”N 2°40’30,9”W.). Zabortegi horretan, Gernikako araztegiko arazketa-lokatzak isuri izan ziren ongarri gisa urteetan zehar; eta, horrela, Gernikako industrian sortutako hainbat kutsatzaile (metal astunak, PAHak, pestizidak, etab.) bertan lurperatu ziren. Isurketaren eraginez gehien kaltetutako espezieen artean, azpimarratzekoak dira landareak eta zizareak edo antzeko lurzoruko ornogabeak; batez ere, berorien eta lurzoru-matrizearen arteko kontaktu estuagatik. Testuinguru horretan, lan honen helburua da lokatz horien isurketak eragindako efektuen ebaluazio bat gauzatzea, lurzoruari beste erabilera bat emate aldera; eta, horretarako, zabalki ezagunak diren test estandarizatu eta biomarkatzaileak erabiliko dira: organismo (uraza eta zizare), denbora (3, 7, 28 eta 56 egunera) eta konplexutasun biologiko desberdinetan (zelula-mailatik populazio-mailara arte). Besteak beste, OECD-204 (toxikotasun akutuaren testa), OECD-222 (ugalketa-testa) eta kaltzeina AM bideragarritasun-testak aplikatu ziren Eisenia fetida zizarean, paraleloki, Lactuca sativa landareetan ernetze- eta elongazio-testak gauzatu ziren heinean. Azterketa toxikologikoen ostean, kontrolarekiko desberdintasun esanguratsuak ikusi ziren: erauzitako zelomozito kantitatean, bideragarritasun zelularrean, ehunetan metatutako metal-kontzentrazioetan, hazkuntza-parametroetan (pisu-galeran) eta ugalketa-parametroetan, kutsatzaileek lurzoru biotan eragindako afekzioa berretsiz. L. sativa espeziarekin egindako frogetan, aldiz, ez zen desberdintasun nabarmenik preziatu talde esperimentalen artean.; Increasing global population, along with a rising industrial activity and soil scarceness led to landfill, spill and filling point extension. Among this landfills, “Landfill 17” can be found with 48046-00181 code; located in Gernika-Lumo (43°19'28,9"N 2°40'30,9"W, Basque Country). There, sewage sludges coming from Gernika waste water treatment plant were poured with a hose with agricultural purposes; thus, many pollutants with industrial origin (heavy metals, PAHs and pesticides among others) ended up in the mentioned soils. Among the species mostly affected by the contamination, plants and earthworms must be highlighted due to their close relation with soil matrix; and therefore, soil pollution. In this context, the aim of this work is to evaluate the effects exerted by pollutants in the spilling in order to assess potential Landfill future uses; using for that widely known biomarkers and standardized tests in different organisms (lettuce and earthworms), exposure times (3, 7, 28 and 56 days) and complexity levels (from cellular level to populational level) for that. Indeed, OECD-204 (acute toxicity test), OECD-222 (reproduction test) and calcein AM tests were applied in Eisenia fetida earthworms; while, germination and elongation tests were applied on Lactuca sativa plants. After carrying out ecotoxicological assays, significant differences respect to the control were observed in: extruded coelomocyte quantity, cell viability, tissue metal accumulations, growth (weight loss) parameters or reproductive parameters; proving pollutants affection upon soil biota. However, no significant differences were observed between experimental groups in those tests carried out with L. sativa

Fine-tuning of SIRT1 expression is essential to protect the liver from cholestatic liver disease

Cholestasis comprises aetiologically heterogeneous conditions characterized by accumulation of bile acids in the liver that actively contribute to liver damage. Sirtuin 1 (SIRT1) regulates liver regeneration and bile acid metabolism by modulating farnesoid X receptor (FXR); we here investigate its role in cholestatic liver disease. We determined SIRT1 expression in livers from patients with cholestatic disease, in two experimental models of cholestasis, as well as in human and murine liver cells in response to bile acid loading. SIRT1-overexpressing (SIRT oe ) and hepatocyte-specific SIRT1-KO (knockout) mice (SIRT hep–/– ) were subjected to bile duct ligation (BDL) and were fed with a 0.1% DDC (3,5-diethoxycarbonyl-1,4-dihydrocollidine) diet to determine the biological relevance of SIRT1 during cholestasis. The effect of NorUDCA (24-norursodeoxycholic acid) was tested in BDL/SIRT oe mice. We found that SIRT1 was highly expressed in livers from cholestatic patients, mice after BDL, and Mdr2 knockout mice (Mdr2 –/– ) animals. The detrimental effects of SIRT1 during cholestasis were validated in vivo and in vitro. SIRT oe mice showed exacerbated parenchymal injury whereas SIRT hep–/– mice evidenced a moderate improvement after BDL and 0.1% DDC feeding. Likewise, hepatocytes isolated from SIRT oe mice showed increased apoptosis in response to bile acids, whereas a significant reduction was observed in SIRT hep–/– hepatocytes. Importantly, the decrease, but not complete inhibition, of SIRT1 exerted by norUDCA treatment correlated with pronounced improvement in liver parenchyma in BDL/SIRT oe mice. Interestingly, both SIRT1 overexpression and hepatocyte-specific SIRT1 depletion correlated with inhibition of FXR, whereas modulation of SIRT1 by NorUDCA associated with restored FXR signaling. Conclusion: SIRT1 expression is increased during human and murine cholestasis. Fine-tuning expression of SIRT1 is essential to protect the liver from cholestatic liver damage

Intestinal microbiome-macrophage crosstalk contributes to cholestatic liver disease by promoting intestinal permeability in mice

Background and Aims: Mounting evidence supports an association between cholestatic liver disease and changes in the composition of the microbiome. Still, the role of the microbiome in the pathogenesis of this condition remains largely undefined.  Approach and Results: To address this, we have used two experimental models, administering alpha-naphtylisocyanate or feeding a 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet, to induce cholestatic liver disease in germ-free mice and germ-free mice conventionalized with the microbiome from wild-type, specific pathogen-free animals. Next, we have inhibited macrophage activation by depleting these cells using clodronate liposomes and inhibiting the inflammasome with a specific inhibitor of NOD-, LRR-, and pyrin domain-containing protein 3. Our results demonstrate that cholestasis, the accumulation of bile acids in the liver, fails to promote liver injury in the absence of the microbiome in vivo. Additional in vitro studies supported that endotoxin sensitizes hepatocytes to bile-acid–induced cell death. We also demonstrate that during cholestasis, macrophages contribute to promoting intestinal permeability and to altered microbiome composition through activation of the inflammasome, overall leading to increased endotoxin flux into the cholestatic liver.  Conclusions: We demonstrate that the intestinal microbiome contributes to cholestasis-mediated cell death and inflammation through mechanisms involving activation of the inflammasome in macrophages

Stabilization of LKB1 and Akt by neddylation regulates energy metabolism in liver cancer

The current view of cancer progression highlights that cancer cells must undergo through a post-translational regulation and metabolic reprogramming to progress in an unfriendly environment. In here, the importance of neddylation modification in liver cancer was investigated. We found that hepatic neddylation was specifically enriched in liver cancer patients with bad prognosis. In addition, the treatment with the neddylation inhibitor MLN4924 in Phb1-KO mice, an animal model of hepatocellular carcinoma showing elevated neddylation, reverted the malignant phenotype. Tumor cell death in vivo translating into liver tumor regression was associated with augmented phosphatidylcholine synthesis by the PEMT pathway, known as a liver-specific tumor suppressor, and restored mitochondrial function and TCA cycle flux. Otherwise, in protumoral hepatocytes, neddylation inhibition resulted in metabolic reprogramming rendering a decrease in oxidative phosphorylation and concomitant tumor cell apoptosis. Moreover, Akt and LKB1, hallmarks of proliferative metabolism, were altered in liver cancer being new targets of neddylation. Importantly, we show that neddylation-induced metabolic reprogramming and apoptosis were dependent on LKB1 and Akt stabilization. Overall, our results implicate neddylation/signaling/metabolism, partly mediated by LKB1 and Akt, in the development of liver cancer, paving the way for novel therapeutic approaches targeting neddylation in hepatocellular carcinoma

Stabilization of LKB1 and Akt by neddylation regulates energy metabolism in liver cancer

The current view of cancer progression highlights that cancer cells must undergo through a post-translational regulation and metabolic reprogramming to progress in an unfriendly environment. In here, the importance of neddylation modification in liver cancer was investigated. We found that hepatic neddylation was specifically enriched in liver cancer patients with bad prognosis. In addition, the treatment with the neddylation inhibitor MLN4924 in Phb1-KO mice, an animal model of hepatocellular carcinoma showing elevated neddylation, reverted the malignant phenotype. Tumor cell death in vivo translating into liver tumor regression was associated with augmented phosphatidylcholine synthesis by the PEMT pathway, known as a liver-specific tumor suppressor, and restored mitochondrial function and TCA cycle flux. Otherwise, in protumoral hepatocytes, neddylation inhibition resulted in metabolic reprogramming rendering a decrease in oxidative phosphorylation and concomitant tumor cell apoptosis. Moreover, Akt and LKB1, hallmarks of proliferative metabolism, were altered in liver cancer being new targets of neddylation. Importantly, we show that neddylation-induced metabolic reprogramming and apoptosis were dependent on LKB1 and Akt stabilization. Overall, our results implicate neddylation/signaling/metabolism, partly mediated by LKB1 and Akt, in the development of liver cancer, paving the way for novel therapeutic approaches targeting neddylation in hepatocellular carcinoma

Resveratrol inhibits nonalcoholic fatty liver disease in rats

<p>Abstract</p> <p>Background</p> <p>The prevalence of nonalcoholic fatty liver disease (NAFLD) is high. NAFLD is linked to obesity, diabetes mellitus, and hypertriglyceridemia. Approximately 20% of patients with NAFLD will eventually develop cirrhosis. Our purpose was to investigate whether resveratrol decreased hepatic steatosis in an animal model of steatosis, and whether this therapeutic approach resulted in a decrease in tumor necrosis factor α (TNF-α) production, lipid peroxidation and oxidative stress.</p> <p>Methods</p> <p>Male Wistar CRL: Wi (Han) (225 g) rats were randomized into three groups. A control group (n = 12) was given free access to regular dry rat chow for 4 weeks. The steatosis (n = 12) and resveratrol (n = 12) groups were given free access to feed (a high carbohydrate-fat free modified diet) and water 4 days per week, and fasted for the remaining 3 days for 4 weeks. Rats in the resveratrol group were given resveratrol 10 mg daily by the oral route. All rats were killed at 4 weeks and assessed for fatty infiltration and bacterial translocation. Levels of TNF-α in serum, hepatic malondialdehyde (MDA), oxidative stress (superoxide dismutase, glutathione peroxidase, catalase and nitric oxide synthase) and biochemical parameters were measured.</p> <p>Results</p> <p>Fat deposition was decreased in the resveratrol group as compared to the steatosis group (Grade 1 vs Grade 3, P < 0.05). TNF-α and MDA levels were significantly increased in the steatosis group (TNF-α; 33.4 ± 5.2 vs 26.24 ± 3.47 pg/ml and MDA; 9.08 ± 0.8 vs 3.17 ± 1.45 μM respectively, <it>P </it>< 0.05). This was accompanied by increased superoxide dismutase, glutathione peroxidase and catalase and decreased nitric oxide synthase in the liver of resveratrol group significantly (<it>P </it>< 0.05 vs steatosis group). Bacterial translocation was not found in any of the groups. Glucose levels were decreased in the group of rats given resveratrol (<it>P </it>< 0.05).</p> <p>Conclusion</p> <p>Resveratrol decreased NAFLD severity in rats. This effect was mediated, at least in part, by TNF-α inhibition and antioxidant activities.</p

Dietary α‐Linolenic Acid, Marine ω‐3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvención con DIeta MEDiterránea (PREDIMED) Study

Background: Epidemiological evidence suggests a cardioprotective role of α‐linolenic acid (ALA), a plant‐derived ω‐3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine ω‐3 fatty acids (long‐chain n‐3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to all‐cause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for long‐chain n‐3 polyunsaturated fatty acids (≥500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvención con DIeta MEDiterránea (PREDIMED) trial. Multivariable‐adjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9‐y follow‐up, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56–0.92) for all‐cause mortality and 0.95 (95% CI 0.58–1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for long‐chain n‐3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67–1.05) for all‐cause mortality, 0.61 (95% CI 0.39–0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29–0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22–1.01) for sudden cardiac death. The highest reduction in all‐cause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45–0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to all‐cause mortality, whereas protection from cardiac mortality is limited to fish‐derived long‐chain n‐3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639

Deregulated neddylation in liver fibrosis

Hepatic fibrosis is a global health problem currently without effective therapeutic approaches. Even though the ubiquitin-like posttranslational modification of neddylation, that conjugates Nedd8 (neural precursor cell expressed developmentally downregulated) to specific targets, is aberrant in many pathologies, its relevance in liver fibrosis (LF) remained unexplored. Our results show deregulated neddylation in clinical fibrosis and both in mouse bileductligationâ and CCl4-induced fibrosis. Importantly, neddylation inhibition, by using the pharmacological inhibitor, MLN4924, reduced liver injury, apoptosis, inflammation, and fibrosis by targeting different hepatic cell types. On one hand, increased neddylation was associated with augmented caspase 3 activity in bile-acidâinduced apoptosis in mouse hepatocytes whereas neddylation inhibition ameliorated apoptosis through reduction of expression of the Cxcl1 and Ccl2 chemokines. On the other hand, chemokine receptors and cytokines, usually induced in activated macrophages, were reduced after neddylation inhibition in mouse Kupffer cells. Under these circumstances, decreased hepatocyte cell death and inflammation after neddylation inhibition could partly account for reduction of hepatic stellate cell (HSC) activation. We provide evidence that augmented neddylation characterizes activated HSCs, suggesting that neddylation inhibition could be important for resolving LF by directly targeting these fibrogenic cells. Indeed, neddylation inhibition in activated HSCs induces apoptosis in a process partly mediated by accumulation of c-Jun, whose cullin-mediated degradation is impaired under these circumstances. Conclusion: Neddylation inhibition reduces fibrosis, suggesting neddylation as a potential and attractive therapeutic target in liver fibrosis. (Hepatology 2017;65:694-709)