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Fructose Mediated Non-Alcoholic Fatty Liver Is Attenuated by HO-1-SIRT1 Module in Murine Hepatocytes and Mice Fed a High Fructose Diet.

Sodhi K, Puri N, Favero G, Stevens S, Meadows C, Abraham NG, Rezzani R, Ansinelli H, Lebovics E, Shapiro JI - PLoS ONE (2015)

Bottom Line: Fructose increased oxidative stress markers and decreased HO-1 and SIRT1 levels in hepatocytes (p<0.05).Increased levels of HO-1 increased SIRT1 levels and ameliorated fructose-mediated lipid accumulation and fibrosis in liver along with decreasing vascular dysfunction (p<0.05 vs. fructose).Taken together, our study demonstrates, for the first time, that HO-1 induction attenuates fructose-induced hepatic lipid deposition, prevents the development of hepatic fibrosis and abates NAFLD-associated vascular dysfunction; effects that are mediated by activation of SIRT1 gene expression.

View Article: PubMed Central - PubMed

Affiliation: Departments of Medicine and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, United States of America.

ABSTRACT

Background: Oxidative stress underlies the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), obesity and cardiovascular disease (CVD). Heme Oxygenase-1 (HO-1) is a potent endogenous antioxidant gene that plays a key role in decreasing oxidative stress. Sirtuin1 (SIRT1) belongs to the family of NAD-dependent de-acyetylases and is modulated by cellular redox.

Hypothesis: We hypothesize that fructose-induced obesity creates an inflammatory and oxidative environment conducive to the development of NAFLD and metabolic syndrome. The aim of this study is to determine whether HO-1 acts through SIRT1 to form a functional module within hepatocytes to attenuate steatohepatitis, hepatic fibrosis and cardiovascular dysfunction.

Methods and results: We examined the effect of fructose, on hepatocyte lipid accumulation and fibrosis in murine hepatocytes and in mice fed a high fructose diet in the presence and absence of CoPP, an inducer of HO-1, and SnMP, an inhibitor of HO activity. Fructose increased oxidative stress markers and decreased HO-1 and SIRT1 levels in hepatocytes (p<0.05). Further fructose supplementation increased FAS, PPARα, pAMPK and triglycerides levels; CoPP negated this increase. Concurrent treatment with CoPP and SIRT1 siRNA in hepatocytes increased FAS, PPARα, pAMPK and triglycerides levels suggesting that HO-1 is upstream of SIRT1 and suppression of SIRT1 attenuates the beneficial effects of HO-1. A high fructose diet increased insulin resistance, blood pressure, markers of oxidative stress and lipogenesis along with fibrotic markers in mice (p<0.05). Increased levels of HO-1 increased SIRT1 levels and ameliorated fructose-mediated lipid accumulation and fibrosis in liver along with decreasing vascular dysfunction (p<0.05 vs. fructose). These beneficial effects of CoPP were reversed by SnMP.

Conclusion: Taken together, our study demonstrates, for the first time, that HO-1 induction attenuates fructose-induced hepatic lipid deposition, prevents the development of hepatic fibrosis and abates NAFLD-associated vascular dysfunction; effects that are mediated by activation of SIRT1 gene expression.

No MeSH data available.


Related in: MedlinePlus

Effect of high-fructose (HFr) supplementation (500 μM) on markers of oxidative stress and HO-1 and SIRT1 gene expressions in hepatocytes treated with and without CoPP (5 μM) and SnMP (5 μM).(A) Isoprostanes level in condition media of hepatocytes (B) heme content measurement in hepatocytes (C) superoxide measurement in hepatocytes. (D) HO-1 mRNA levels (E) SIRT-1 protein levels. (F) Effect of Biliverdin and Tempol on SIRT1 expression in fructose (Fr)-treated hepatocytes. Hepatocytes were treated with biliverdin (10 μM) and with Tempol (100 μM) in presence of fructose (500 μM) for 24 hours. Results are mean±SE, n = 6/group. * p<0.05 vs CTR; # p<0.05 vs HFr, + p<0.05 vs HFr+CoPP.
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pone.0128648.g001: Effect of high-fructose (HFr) supplementation (500 μM) on markers of oxidative stress and HO-1 and SIRT1 gene expressions in hepatocytes treated with and without CoPP (5 μM) and SnMP (5 μM).(A) Isoprostanes level in condition media of hepatocytes (B) heme content measurement in hepatocytes (C) superoxide measurement in hepatocytes. (D) HO-1 mRNA levels (E) SIRT-1 protein levels. (F) Effect of Biliverdin and Tempol on SIRT1 expression in fructose (Fr)-treated hepatocytes. Hepatocytes were treated with biliverdin (10 μM) and with Tempol (100 μM) in presence of fructose (500 μM) for 24 hours. Results are mean±SE, n = 6/group. * p<0.05 vs CTR; # p<0.05 vs HFr, + p<0.05 vs HFr+CoPP.

Mentions: In accordance with our hypothesis our results showed that cultured murine hepatocytes treated with HFr increased isoprostane levels obtained from conditioned media as compared to the control. CoPP decreased isoprostane levels (p<0.05) (Fig 1A) and concurrent treatment with SnMP reversed the beneficial effects of CoPP. Similarly heme and superoxide levels were increased in murine hepatocytes treated with HFr as compared to the control. CoPP decreased heme and superoxide levels as compared to HFr treatment (Fig 1B and 1C respectively, p<0.05) and concurrent treatment with SnMP reversed the beneficial effects of CoPP, indicating that HO activity is required for the reduction in these oxidative markers.


Fructose Mediated Non-Alcoholic Fatty Liver Is Attenuated by HO-1-SIRT1 Module in Murine Hepatocytes and Mice Fed a High Fructose Diet.

Sodhi K, Puri N, Favero G, Stevens S, Meadows C, Abraham NG, Rezzani R, Ansinelli H, Lebovics E, Shapiro JI - PLoS ONE (2015)

Effect of high-fructose (HFr) supplementation (500 μM) on markers of oxidative stress and HO-1 and SIRT1 gene expressions in hepatocytes treated with and without CoPP (5 μM) and SnMP (5 μM).(A) Isoprostanes level in condition media of hepatocytes (B) heme content measurement in hepatocytes (C) superoxide measurement in hepatocytes. (D) HO-1 mRNA levels (E) SIRT-1 protein levels. (F) Effect of Biliverdin and Tempol on SIRT1 expression in fructose (Fr)-treated hepatocytes. Hepatocytes were treated with biliverdin (10 μM) and with Tempol (100 μM) in presence of fructose (500 μM) for 24 hours. Results are mean±SE, n = 6/group. * p<0.05 vs CTR; # p<0.05 vs HFr, + p<0.05 vs HFr+CoPP.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4476565&req=5

pone.0128648.g001: Effect of high-fructose (HFr) supplementation (500 μM) on markers of oxidative stress and HO-1 and SIRT1 gene expressions in hepatocytes treated with and without CoPP (5 μM) and SnMP (5 μM).(A) Isoprostanes level in condition media of hepatocytes (B) heme content measurement in hepatocytes (C) superoxide measurement in hepatocytes. (D) HO-1 mRNA levels (E) SIRT-1 protein levels. (F) Effect of Biliverdin and Tempol on SIRT1 expression in fructose (Fr)-treated hepatocytes. Hepatocytes were treated with biliverdin (10 μM) and with Tempol (100 μM) in presence of fructose (500 μM) for 24 hours. Results are mean±SE, n = 6/group. * p<0.05 vs CTR; # p<0.05 vs HFr, + p<0.05 vs HFr+CoPP.
Mentions: In accordance with our hypothesis our results showed that cultured murine hepatocytes treated with HFr increased isoprostane levels obtained from conditioned media as compared to the control. CoPP decreased isoprostane levels (p<0.05) (Fig 1A) and concurrent treatment with SnMP reversed the beneficial effects of CoPP. Similarly heme and superoxide levels were increased in murine hepatocytes treated with HFr as compared to the control. CoPP decreased heme and superoxide levels as compared to HFr treatment (Fig 1B and 1C respectively, p<0.05) and concurrent treatment with SnMP reversed the beneficial effects of CoPP, indicating that HO activity is required for the reduction in these oxidative markers.

Bottom Line: Fructose increased oxidative stress markers and decreased HO-1 and SIRT1 levels in hepatocytes (p<0.05).Increased levels of HO-1 increased SIRT1 levels and ameliorated fructose-mediated lipid accumulation and fibrosis in liver along with decreasing vascular dysfunction (p<0.05 vs. fructose).Taken together, our study demonstrates, for the first time, that HO-1 induction attenuates fructose-induced hepatic lipid deposition, prevents the development of hepatic fibrosis and abates NAFLD-associated vascular dysfunction; effects that are mediated by activation of SIRT1 gene expression.

View Article: PubMed Central - PubMed

Affiliation: Departments of Medicine and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, United States of America.

ABSTRACT

Background: Oxidative stress underlies the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), obesity and cardiovascular disease (CVD). Heme Oxygenase-1 (HO-1) is a potent endogenous antioxidant gene that plays a key role in decreasing oxidative stress. Sirtuin1 (SIRT1) belongs to the family of NAD-dependent de-acyetylases and is modulated by cellular redox.

Hypothesis: We hypothesize that fructose-induced obesity creates an inflammatory and oxidative environment conducive to the development of NAFLD and metabolic syndrome. The aim of this study is to determine whether HO-1 acts through SIRT1 to form a functional module within hepatocytes to attenuate steatohepatitis, hepatic fibrosis and cardiovascular dysfunction.

Methods and results: We examined the effect of fructose, on hepatocyte lipid accumulation and fibrosis in murine hepatocytes and in mice fed a high fructose diet in the presence and absence of CoPP, an inducer of HO-1, and SnMP, an inhibitor of HO activity. Fructose increased oxidative stress markers and decreased HO-1 and SIRT1 levels in hepatocytes (p<0.05). Further fructose supplementation increased FAS, PPARα, pAMPK and triglycerides levels; CoPP negated this increase. Concurrent treatment with CoPP and SIRT1 siRNA in hepatocytes increased FAS, PPARα, pAMPK and triglycerides levels suggesting that HO-1 is upstream of SIRT1 and suppression of SIRT1 attenuates the beneficial effects of HO-1. A high fructose diet increased insulin resistance, blood pressure, markers of oxidative stress and lipogenesis along with fibrotic markers in mice (p<0.05). Increased levels of HO-1 increased SIRT1 levels and ameliorated fructose-mediated lipid accumulation and fibrosis in liver along with decreasing vascular dysfunction (p<0.05 vs. fructose). These beneficial effects of CoPP were reversed by SnMP.

Conclusion: Taken together, our study demonstrates, for the first time, that HO-1 induction attenuates fructose-induced hepatic lipid deposition, prevents the development of hepatic fibrosis and abates NAFLD-associated vascular dysfunction; effects that are mediated by activation of SIRT1 gene expression.

No MeSH data available.


Related in: MedlinePlus