scholarly journals Dihydromyricetin attenuates palmitic acid-induced oxidative stress by promoting autophagy via SIRT3-ATG4B signaling in hepatocytes

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Li Huang ◽  
Xianglong Zeng ◽  
Bo Li ◽  
Cong Wang ◽  
Min Zhou ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Palmitic Acid ◽  
Hepg2 Cells ◽  
Underlying Mechanism ◽  
Protective Effects ◽  
Inhibitory Effects ◽  
Mitochondrial Ros ◽  
Intracellular Ros ◽  
Protein Expressions ◽  
And Oxidative Stress

Abstract Background Oxidative stress in hepatocytes was important pathogenesis of nonalcoholic steatohepatitis (NASH). Autophagy was a cellular process that can remove damaged organelles under oxidative stress, and thus presented a potential therapeutic target against NASH. This work aimed to investigate whether autophagy was participated in the protective effects of dihydromyricetin (DHM) on palmitic acid (PA)-induced oxidative stress in hepatocytes and the underlying mechanism. Methods HepG2 and HHL-5 cell lines were pretreated with DHM (20 μM) for 2 h, followed by PA (0.2 mM) treatment for 16 h. The oxidative stress was assessed by the quantification of intracellular reactive oxygen species (ROS), mitochondrial ROS (mtROS), mitochondrial membrane potential (MMP) and mitochondrial ultrastructural analyses. The protein expressions of SIRT3, LC3I/II, P62 and ATG4B, as well as the acetylation of AGT4B were determined by western blotting using HepG2 and HepG2/ATG4B± cells with heterozygous knockout of ATG4B. Results Exposure to PA resulted in increased intracellular ROS and mtROS, decreased MMP and aggravated mitochondrial injury in HepG2 cells, which were notably attenuated by DHM treatment. DHM-induced inhibition of oxidative stress was associated with the induction of autophagy, characterized by upregulated ATG4B and LC3 II as well as downregulated P62 levels. Furthermore, the inhibitory effects of DHM on PA-induced autophagy arrest and oxidative stress were eliminated when pretreated with a SIRT3 inhibitor 3-TYP or conducted in HepG2/ATG4B± cells, suggesting that SIRT3 and ATG4B were involved in DHM-induced benefits. Moreover, DHM treatment increased the protein expression of SIRT3 and SIRT3-dependent deacetylation of ATG4B in HepG2 cells. Conclusion Our results demonstrated that DHM attenuated PA-induced oxidative stress in hepatocytes through induction of autophagy, which was mediated through the increased expression of SIRT3 and SIRT3-mediated ATG4B deacetylation following DHM treatment.

scholarly journals Dihydromyricetin Attenuates Palmitate Acid-Induced Oxidative Stress by promoting Autophagy via SIRT3-ATG4B Signaling in Hepatocytes

2021 ◽  
Author(s):  
Mantian Mi ◽  
Li Huang ◽  
Xianglong Zeng ◽  
Bo Li ◽  
Cong Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hepg2 Cells ◽  
Underlying Mechanism ◽  
Protective Effects ◽  
Inhibitory Effects ◽  
Potential Therapeutic Target ◽  
Mitochondrial Ros ◽  
Intracellular Ros ◽  
Protein Expressions ◽  
And Oxidative Stress

Abstract Background Oxidative stress in hepatocytes was an important pathogenesis of nonalcoholic steatohepatitis (NASH). Autophagy was a cellular process that can remove damaged organelles under oxidative stress, and thus presented a potential therapeutic target against NASH. The aim of this work was to investigate whether autophagy participated the protective effects of dihydromyricetin (DHM) on palmitic acid (PA)-induced oxidative stress in hepatocytes and the underlying mechanism. Methods HepG2 cells were pretreated with DHM (20 µM) for 2 h, followed by PA (0.2 mM) treatment for 16 h. The oxidative stress was assessed by the quantification of intracellular reactive oxygen species (ROS), mitochondrial ROS (mtROS), mitochondrial membrane potential (MMP) and mitochondrial ultrastructural analyses. The protein expressions of SIRT3, LC3I/II, P62 and ATG4B, as well as the acetylation of AGT4B were determined by western blotting using HepG2 and HepG2/ ATG4B+/− cells with heterozygous knockout of ATG4B. Results Exposure to PA resulted in increased intracellular ROS and mtROS, decreased MMP and aggravated mitochondrial injury in HepG2 cells, which were notably attenuated by DHM treatment. DHM-induced inhibition of oxidative stress was associated with the induction of autophagy, characterized by upregulated ATG4B and LC3 II as well as downregulated P62 levels. Furthermore, the inhibitory effects of DHM on PA-induced autophagy arrest and oxidative stress were eliminated when pretreated with a SIRT3 inhibitor 3-TYP or conducted in HepG2/ATG4B+/− cells, suggesting that SIRT3 and ATG4B were involved in DHM-induced benefits. Moreover, DHM treatment increased the protein expression of SIRT3 and SIRT3-dependent deacetylation of ATG4B in HepG2 cells. Conclusion Our results demonstrated that DHM attenuated PA-induced oxidative stress in hepatocytes through induction of autophagy, which was mediated through the increased expression of SIRT3 and SIRT3-mediated ATG4B deacetylation following DHM treatment.

The protective effects of carvacrol and thymol against paracetamol–induced toxicity on human hepatocellular carcinoma cell lines (HepG2)

2016 ◽  
Vol 35 (12) ◽  
pp. 1252-1263 ◽  
Author(s):  
SS Palabiyik ◽  
E Karakus ◽  
Z Halici ◽  
E Cadirci ◽  
Y Bayir ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Cytokines ◽  
Hepg2 Cells ◽  
Folk Medicine ◽  
Hepatoprotective Activity ◽  
High Dose ◽  
Protective Effects ◽  
And Oxidative Stress ◽  
Pro Inflammatory Cytokines

Acetaminophen (APAP) overdose could induce liver damage and lead to acute liver failure. The treatment of APAP overdoses could be improved by new therapeutic strategies. Thymus spp., which has many beneficial effects and has been used in folk medicine, is one such potential strategy. In the present study, the hepatoprotective activity of the main constituents of Thymus spp., carvacrol and thymol, were evaluated in light of APAP-induced hepatotoxicity. We hoped to understand the hepatoprotective mechanism of these agents on the antioxidant system and pro-inflammatory cytokines in vitro. Dose-dependent effects of thymol and carvacrol (25, 50, and 100 µM) were tested on cultured HepG2 cells. N-Acetylcysteine (NAC) was tested as positive control. We showed that APAP inhibited HepG2 cell growth by inducing inflammation and oxidative stress. Incubating APAP-exposed HepG2 cells with carvacrol and thymol for 24 h ameliorated this inflammation and oxidative stress. We also evaluated alanine transaminase and lactate dehydrogenase levels of HepG2 cells. We found that thymol and carvacrol protected against APAP-induced toxicity in HepG2 cells by increasing antioxidant activity and reducing pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 1β. Taking together high-dose thymol and carvacrol treatment has an effect close to NAC treatment in APAP toxicity, but thymol has better treatment effect than carvacrol.

scholarly journals Apelin Promotes ECM Synthesis by Enhancing Autophagy Flux via TFEB in Human Degenerative NP Cells under Oxidative Stress

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Wei Jiang ◽  
Pei Zhao ◽  
Xuemei Zhang
Keyword(s):  
Oxidative Stress ◽  
Western Blot ◽  
Underlying Mechanism ◽  
Autophagic Flux ◽  
Rt Pcr ◽  
Autophagy Flux ◽  
Protein Expressions ◽  
Collagen Ii ◽  
The Relationship ◽  
And Oxidative Stress

Background. Apelin alleviates oxidative stress which contributes to the development of aging. IVDD is a disease closely correlated to aging and oxidative stress which is known to be harmful to NP cells’ matrix synthesis. The purpose of the present study was to investigate the role and underlying mechanism of Apelin in NP cells’ matrix degradation under oxidative stress. Methods. First, the mRNA and protein expressions of Apelin were checked by RT-PCR and Western blot in NP from normal and degenerative IVD to explore the relationship between Apelin and IVDD preliminarily. Then, H2O2 was used to mimic oxidative stress of NP cells. After treated with Apelin 13 and CQ, the GAG content was assessed by DMMB and the mRNA/protein expressions of NP matrix macromolecules (Collagen II and Aggrecan) and autophagy-related markers (LC3 and p62) were assessed by RT-PCR/Western blot. Finally, TFEB was knocked down by esiRNA-TFEB transfection and the nucleoprotein expression of TFEB and autophagy-related markers (LC3 and p62) were assessed by Western blot to discuss whether TFEB is involved in Apelin regulating autophagy flux in NP cells under oxidative stress. Results. Our data first confirmed that the mRNA and protein expressions of Apelin were decreased with IVDD. Furthermore, Apelin increased GAG content of NP cells and mRNA/protein expressions of NP matrix macromolecules (Collagen II and Aggrecan) and promoted autophagic flux (LC3II/I increased and p62 decreased) under oxidative stress. Finally, after transfected with esiRNA-TFEB, Apelin cannot promote autophagic flux any more in human degenerative NP cells. Conclusion. Our data indicated that Apelin promotes ECM synthesis by enhancing autophagy flux via TFEB in human degenerative NP cells under oxidative stress. This viewpoint may provide a new therapeutic idea for IVDD.

scholarly journals Metformin alleviates insulin resistance in obese-induced mice via remodeling gut microbiota and intestinal metabolites

2020 ◽  
Author(s):  
Ya Zhang ◽  
Yang Cheng ◽  
Jihui Zuo ◽  
Liping Yan ◽  
Qiaojuan Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Gut Microbiota ◽  
High Fat Diet ◽  
Underlying Mechanism ◽  
Liver Inflammation ◽  
High Fat ◽  
Intracellular Ros ◽  
And Oxidative Stress

AbstractMetformin is widely used to surmount insulin resistance (IR) and diabetes. Evidence indicates that metformin remodels gut microbiota but the underlying mechanism remain unclear. Present results showed that metformin effectively improved insulin sensitivity and alleviated liver inflammation and oxidative stress in high fat diet (HFD)-induced mice. Metabolomics analysis showed that metformin increased tauroursodeoxycholic acid (TUDCA) production by increasing the expression of bile acid synthase Cyp7a1 and Baat. In the palmitic acid (PA)-induced cell, TUDCA activated Nrf2/ARE pathway, thereby reducing intracellular ROS and improving insulin signaling. Further gut microbiota analysis showed that metformin increased the proportion of Akkermanisia muciniphlia in the HFD-fed mice, while TUDCA promoted the proliferation of A. muciniphlia but metformin did not. These findings reveal that metformin remodels the gut microbiota, reduces oxidative stress and enhances insulin sensitivity by increasing the production of TUDCA. This provides a novel mechanism by which metformin alleviates diet-induced IR and improves metabolism.

Effects of Montmorillonite on Growth Performance, Serum Biochemistry and Oxidative Stress of Red-Crowned Crane (Grus japonensis) Fed Mycotoxin-Contaminated Feed

2020 ◽  
Vol 21 (8) ◽  
pp. 626-632 ◽  
Author(s):  
Dawei Liu ◽  
Qinghua Wu ◽  
Hongyi Liu ◽  
Changhu Lu ◽  
Chao Gu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Growth Performance ◽  
Feed Intake ◽  
Animal Feed ◽  
Bird Species ◽  
Serum Biochemistry ◽  
Protective Effects ◽  
Regular Diet ◽  
Grus Japonensis ◽  
And Oxidative Stress

Background: The red-crowned crane (Grus japonensis) is one of the most vulnerable bird species in the world. Mycotoxins are toxic secondary metabolites produced by fungi and considered naturally unavoidable contaminants in animal feed. Our recent survey indicated that the mycotoxins had the potential to contaminate redcrowned crane’s regular diets in China. Objective: This experiment was conducted to investigate the protective effects of mycotoxin binder montmorillonite (Mont) on growth performance, serum biochemistry and oxidative stress parameters of the red-crowned crane. Methods: 16 red-crowned cranes were divided into four groups and fed one of the following diets; a selected diet, regular diet, or the selected diet or regular diet with 0.5% montmorillonite added to the diets. The cranes' parameters of performance, hematology, serum biochemistry and serum oxidative stress were measured. Results: Consuming regular diets decreased the average daily feed intake (ADFI), levels of haemoglobin (Hb), platelet count (PLT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), but increased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH). The supplementation of 0.5% Mont provided protection for the red-crowned crane in terms of feed intake, serum biochemistry and oxidative stress. Moreover, Mont supplementation had no adverse effect on the health of red-crowned crane. Conclusions: Taken together, these findings suggested that the addition of dietary Mont is effective in improving the health of red-crowned crane.

Hydrogen peroxide and quercetin induced changes on cell viability, apoptosis and oxidative stress in HepG2 cells

2020 ◽  
Vol 01 ◽  
Author(s):  
Ayşe Mine Yılmaz ◽  
Gökhan Biçim ◽  
Kübra Toprak ◽  
Betül Karademir Yılmaz ◽  
Irina Milisav ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Hydrogen Peroxide ◽  
Cell Viability ◽  
Hepg2 Cells ◽  
Proteasome Activity ◽  
Cell Cycle Phases ◽  
Induced Changes ◽  
And Oxidative Stress ◽  
Quercetin Treatment

Background: Different cellular responses influence the progress of cancer. In this study, we have investigated the effect of hydrogen peroxide and quercetin induced changes on cell viability, apoptosis and oxidative stress in human hepatocellular carcinoma (HepG2) cells. Methods: The effects of hydrogen peroxide and quercetin on cell viability, cell cycle phases and oxidative stress related cellular changes were investigated. Cell viability was assessed by WST-1 assay. Apoptosis rate, cell cycle phase changes and oxidative stress were measured by flow cytometry. Protein expressions of p21, p27, p53, NF-Kβ-p50 and proteasome activity were determined by Western blot and fluorometry, respectively. Results: Hydrogen peroxide and quercetin treatment resulted in decreased cell viability and increased apoptosis in HepG2 cells. Proteasome activity was increased by hydrogen peroxide but decreased by quercetin treatment. Conclusion: Both agents resulted in decreased p53 protein expression and increased cell death by different mechanisms regarding proteostasis and cell cycle phases.

MiR-22-3p Suppresses Vascular Remodeling and Oxidative Stress by Targeting CHD9 during the Development of Hypertension

2021 ◽  
pp. 1-11
Author(s):  
Hanqing Chen ◽  
Xiru Xu ◽  
Zhengqing Liu ◽  
Yong Wu
Keyword(s):  
Oxidative Stress ◽  
Vascular Remodeling ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
Spontaneously Hypertensive ◽  
Aortic Smooth Muscle ◽  
Phenotype Switch ◽  
And Oxidative Stress

Hypertension is considered a risk factor for a series of systematic diseases. Known factors including genetic predisposition, age, and diet habits are strongly associated with the initiation of hypertension. The current study aimed to investigate the role of miR-22-3p in hypertension. In this study, we discovered that the miR-22-3p level was significantly decreased in the thoracic aortic vascular tissues and aortic smooth muscle cells (ASMCs) of spontaneously hypertensive rats. Functionally, the overexpression of miR-22-3p facilitated the switch of ASMCs from the synthetic to contractile phenotype. To investigate the underlying mechanism, we predicted 11 potential target mRNAs for miR-22-3p. After screening, chromodomain helicase DNA-binding 9 (CHD9) was validated to bind with miR-22-3p. Rescue assays showed that the co-overexpression of miR-22-3p and CHD9 reversed the inhibitory effect of miR-22-3p mimics on cell proliferation, migration, and oxidative stress in ASMCs. Finally, miR-22-3p suppressed vascular remodeling and oxidative stress in vivo. Overall, miR-22-3p regulated ASMC phenotype switch by targeting CHD9. This new discovery provides a potential insight into hypertension treatment.

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