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 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.

Downregulation of General Control Nonderepressible 2/Eukaryotic Initiation Factor 2α Attenuates Inflammation, Oxidative Stress and Cell Apoptosis in Retinal Cells Induced by High Glucose

2021 ◽  
Vol 11 (8) ◽  
pp. 1497-1505
Author(s):  
Shuyu Zhao ◽  
Yuqian Yin ◽  
Hong Qin
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cell ◽  
Western Blot ◽  
High Glucose ◽  
Cell Apoptosis ◽  
Colorimetric Method ◽  
Underlying Mechanism ◽  
Initiation Factor ◽  
Western Blot Assay ◽  
And Oxidative Stress

Background: Diabetic retinopathy (DR), the frequent complication of diabetes mellitus, has been the main factor of clinical blindness. It is of great clinical significance to seek a novel therapeutic target of DR. The present study aims to investigate the important role of GCN2/eIF2α in DR and the underlying mechanism. Materials and Methods: The expression levels of GCN2 and p-eIF2α were measured by western blot assay and q-PCR. The inflammation levels were assessed by ELISA assay and oxidative stress was measured by colorimetric method. Then, the key proteins related to the function of endothelial cell were measured by western blot assay. Cell apoptotic rate was detected by flow cytometry and proteins related to cell apoptosis were detected by western blot assay. Results: High glucose activated GCN2/eIF2α signaling pathway in HRCECs. Downregulation of GCN2 attenuated HG-induced cell apoptosis, inflammatory and oxidative stress in HRCECs. Meanwhile, downregulation of GCN2 ameliorated HG-induced endothelial cell dysfunction. Inhibition of GCN2 inhibited p-eIF2α, ATF4, CHOP and activated UCP2. Conclusion: The results in this study proved that knockdown of GCN2 could significantly mitigate HG-induced injury, suggesting GCN2/eIF2α as a potential target for DR therapy.

scholarly journals Downregulation of long non-coding RNA SNHG7 protects against inflammation and apoptosis in Parkinson's disease model by targeting miR-425-5p/TRAF5/NF-κB axis

2020 ◽  
Author(s):  
Shan Yu ◽  
Xueshibojie Liu ◽  
Duo Yu ◽  
Changyong E ◽  
Jinghui Yang
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Western Blot ◽  
Inflammatory Cytokines ◽  
Neuronal Apoptosis ◽  
Rt Pcr ◽  
Non Coding Rna ◽  
Long Non Coding Rna ◽  
And Oxidative Stress

Abstract Background Accumulated evidence has established that long non-coding RNA (lncRNA) is involved in the progress of Parkinson's disease (PD). SNHG7, a novel lncRNA, has been found to play a key role in tumorigenesis. However, the SNHG7 expression and its functional effects on PD remain uncharted. Methods RT-PCR was used to detect the expression of SNHG7, miR-425-5p and inflammatory cytokines in the plasma of PD patients and the healthy controls. Rotenone (Rot) was adopted to construct PD models in SD rats and SH-SY5Y cells, respectively. Gain- and loss- of functions of SNHG7 or miR-425-5p were conducted. The expression levels of Caspase3, tyrosine hydroxylase (TH), Iba1 in SD rat striatum was measured via immunohistochemistry and Western blot. Additionally, the expressions of inflammatory cytokines (IL-1β, IL-6, TNF-α) and oxidative stress factors (MDA, SOD, GSH-PX) in the brain tissues were examined using RT-PCR and ELISA. Moreover, the protein levels of TRAF5, I-κB, NF-κB, HO-1, Nrf2 were detected via Western blot. Bioinformatics was applied to predict the targeting relationship between SNHG7, miR-425-5p and TRAF5. Dual luciferase activity assay and RNA immunoprecipitation (RIP) assays were carried out to verify their interactions. Results SNHG7 was found up-regulated in PD patients while miR-425-5p expression was down-regulated (compared to healthy donors). Meanwhile, SNHG7 level was positively correlated with the level of inflammatory cytokines in PD patients. Functional experiments confirmed that SNHG7 downregulation or miR-425-5p overexpression attenuated neuronal apoptosis in the Rot-mediated PD model, TH-positive cell loss and microglia activation by mitigating inflammation and oxidative stress. Mechanistically, SNHG7 served as a competitive endogenous RNA (ceRNA) by sponging miR-425-5p and promoted TRAF5 mediated inflammation and oxidative stress. Conclusion Inhibition of SNHG7 ameliorated neuronal apoptosis in PD through relieving miR-425-5p/TRAF5/NF-κB signaling pathway modulated inflammation and oxidative stress.

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 Activation of CD137 Signaling Enhances Vascular Calcification through c-Jun N-Terminal Kinase-Dependent Disruption of Autophagic Flux

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Rui Chen ◽  
Yao Xu ◽  
Wei Zhong ◽  
Bo Li ◽  
Ping Yang ◽  
...  
Keyword(s):  
Western Blot ◽  
Vascular Calcification ◽  
Underlying Mechanism ◽  
Calcium Deposition ◽  
Control Group ◽  
Autophagic Flux ◽  
Autophagy Flux ◽  
Alp Activity

Background. Vascular calcification is widespread and clinically significant, contributing to substantial morbidity and mortality. Calcifying vascular cells are partly derived from local vascular smooth muscle cells (VSMCs), which can undergo chondrogenic or osteogenic differentiation under inflammatory environment. Recently, we have found activation of CD137 signaling accelerated vascular calcification. However, the underlying mechanism remains unknown. This study aims to identify key mediators involved in CD137 signaling-induced vascular calcification in vivo and in vitro. Methods. Autophagy flux was measured through mRFP-GFP-LC3 adenovirus and transmission electron microscopy. Von Kossa assay and alkaline phosphatase (ALP) activity were used to observe calcification in vivo and in vitro, respectively. Autophagosome-containing vesicles were collected and identified by flow cytometry and Western blot. Autophagy or calcification-associated targets were measured by Western blot, quantitative real-time PCR, and immunohistochemistry. Results. Treatment with the agonist-CD137 displayed c-Jun N-terminal kinase- (JNK-) dependent increase in the expression of various markers of autophagy and the number of autophagosomes relative to the control group. Autophagy flux experiments suggested that agonist-CD137 blocked the fusion of autophagosomes with lysosomes in cultured VSMCs. Calcium deposition, ALP activity, and the expression of calcification-associated proteins also increased in agonist-CD137 group compared with anti-CD137 group, which could be recovered by autophagy stimulator rapamycin. Autophagosome-containing vesicles collected from agonist-CD137 VSMCs supernatant promoted VSMC calcification. Conclusion. The present study identified a new pathway in which CD137 promotes VSMC calcification through the activation of JNK signaling, subsequently leading to the disruption of autophagic flux, which is responsible for CD137-induced acceleration of vascular calcification.

Febuxostat Attenuates the Progression of Periodontitis in Rats

Pharmacology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Naseratun Nessa ◽  
Miyuki Kobara ◽  
Hiroe Toba ◽  
Tetsuya Adachi ◽  
Toshiro Yamamoto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Bone Resorption ◽  
Alveolar Bone ◽  
Alveolar Bone Loss ◽  
Gingival Tissue ◽  
Systemic Effects ◽  
Rt Pcr ◽  
Tnf Α ◽  
And Oxidative Stress

Introduction: Periodontitis is a lifestyle-related disease that is characterized by chronic inflammation in gingival tissue. Febuxostat, a xanthine oxidase inhibitor, exerts anti-inflammatory and antioxidant effects. Objective: The present study investigated the effects of febuxostat on periodontitis in a rat model. Methods: Male Wistar rats were divided into 3 groups: control, periodontitis, and febuxostat-treated periodontitis groups. Periodontitis was induced by placing a ligature wire around the 2nd maxillary molar and the administration of febuxostat (5 mg/kg/day) was then initiated. After 4 weeks, alveolar bone loss was assessed by micro-computed tomography and methylene blue staining. The expression of osteoprotegerin (OPG), a bone resorption inhibitor, was detected by quantitative RT-PCR and immunological staining, and the number of osteoclasts in gingival tissue was assessed by tartrate-resistant acid phosphatase staining. The mRNA and protein expression levels of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β), in gingival tissue were measured using quantitative RT-PCR and immunological staining. Oxidative stress in gingival tissue was evaluated by the expression of 4-hydroxy-2-nonenal (4-HNE), and 8-hydroxy-2-deoxyguanosine (8-OHdG). To clarify the systemic effects of periodontitis, blood pressure and glucose tolerance were examined. Results: In rats with periodontitis, alveolar bone resorption was associated with reductions in OPG and increases in osteoclast numbers. The gingival expression of TNF-α, IL-1β, 4-HNE, and 8-OHdG was up-regulated in rats with periodontitis. Febuxostat significantly reduced alveolar bone loss, proinflammatory cytokine levels, and oxidative stress. It also attenuated periodontitis-induced glucose intolerance and blood pressure elevations. Conclusion: Febuxostat prevented the progression of periodontitis and associated systemic effects by inhibiting proinflammatory mediators and oxidative stress.

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.

The Association between Oxidative Stress and Cardiac Functions in Infants Born to Preeclamptic Mothers

2018 ◽  
Vol 36 (11) ◽  
pp. 1205-1210
Author(s):  
Didem Arman ◽  
Secil Ercin ◽  
Sevilay Topcuoğlu ◽  
Ayşem Kaya ◽  
Taner Yavuz ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Premature Infants ◽  
Stress Index ◽  
Control Group ◽  
Cardiac Functions ◽  
Total Antioxidant ◽  
Echocardiographic Parameters ◽  
Oxidant Status ◽  
The Relationship ◽  
And Oxidative Stress

Objective The present study aimed to assess the global oxidant and antioxidant status in infants born to preeclamptic mothers and their correlation with cardiac functions. Study Design We compared 40 infants born to preeclamptic mothers with 40 premature infants born to normotensive mothers. We assessed the relationship between echocardiographic measurements and total antioxidant capacity (TAC) and total oxidant status (TOS) values. Results In the study group, TAC, TOS, and oxidative stress index (OSI) levels were significantly higher in the cord blood (p = 0.03, 0.04, and 0.039, respectively) than in the control group. We did not observe any correlation between echocardiographic measurements and TAC, TOS, and OSI levels in infants born to preeclamptic mothers. Conclusion Compared with the control group, despite higher TAC levels in infants born to preeclamptic mothers, concurrent elevated OSI levels reveal that the oxidant–antioxidant balance is disturbed in favor of oxidants. Furthermore, the findings of this study suggest that echocardiographic parameters are unaffected by the oxidant status.

Relationship between aldose reductase enzyme and the signaling pathway of protein kinase C in an in vitro diabetic retinopathy model

2020 ◽  
Vol 98 (4) ◽  
pp. 243-251
Author(s):  
Mutlu Sarikaya ◽  
Nuray Yazihan ◽  
Net Daş Evcimen
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Signaling Molecules ◽  
Protein Levels ◽  
Kinase C ◽  
The Relationship ◽  
And Oxidative Stress ◽  
Expression And Activity

Protein kinase C (PKC) and aldose reductase (AR) enzyme activities are increased in diabetes and complications are include retinopathy, nephropathy, and neuropathy. However, the relationship between PKC and AR and the underlying molecular mechanisms is still unclear. We aimed to evaluate the relationship between these two enzymes and clarify the underlying molecular mechanisms by the related signaling molecules. The effects of hyperglycemia and oxidative stress on AR and PKC enzymes and the signaling molecules such as nuclear factor-kappa B (NF-κB), inhibitor kappa B-alpha (IkB-α), total c-Jun, phospho c-Jun, and stress-activated protein kinases (SAPK)/Jun amino-terminal kinases (JNK) were evaluated in human retinal pigment epithelial cells (ARPE-19). AR, PKC protein levels, and related signaling molecules increased with hyperglycemia and oxidative stress. The AR inhibitor sorbinil decreased PKC expression and activity and all signaling molecule protein levels. Increased AR expression during hyperglycemia and oxidative stress was found to be correlated with the increase in PKC expression and activity in both conditions. Decreased expression and activity of PKC and the protein levels of related signaling molecules with the AR inhibitor sorbinil showed that AR enzyme may play a key role in the expression of PKC enzyme and oxidative stress during diabetes.

scholarly journals Kaempferol and Kaempferide Attenuate Oleic Acid-Induced Lipid Accumulation and Oxidative Stress in HepG2 Cells

2021 ◽  
Vol 22 (16) ◽  
pp. 8847
Author(s):  
Fangfang Tie ◽  
Jin Ding ◽  
Na Hu ◽  
Qi Dong ◽  
Zhi Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oleic Acid ◽  
Lipid Metabolism ◽  
Western Blot ◽  
Blot Analysis ◽  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Western Blot Analysis ◽  
Heme Oxygenase 1 ◽  
And Oxidative Stress

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases which lacks ideal treatment options. Kaempferol and kaempferide, two natural flavonol compounds isolated from Hippophae rhamnoides L., were reported to exhibit a strong regulatory effect on lipid metabolism, for which the mechanism is largely unknown. In the present study, we investigated the effects of kaempferol and kaempferide on oleic acid (OA)-treated HepG2 cells, a widely used in vitro model of NAFLD. The results indicated an increased accumulation of lipid droplets and triacylglycerol (TG) by OA, which was attenuated by kaempferol and kaempferide (5, 10 and 20 μM). Western blot analysis demonstrated that kaempferol and kaempferide reduced expression of lipogenesis-related proteins, including sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and stearoyl-CoA desaturase 1 (SCD-1). Expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer binding proteins β (C/EBPβ), two adipogenic transcription factors, was also decreased by kaempferol and kaempferide treatment. In addition, western blot analysis also demonstrated that kaempferol and kaempferide reduced expression of heme oxygenase-1 (HO-1) and nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Molecular docking was performed to identify the direct molecular targets of kaempferol and kaempferide, and their binding to SCD-1, a critical regulator in lipid metabolism, was revealed. Taken together, our findings demonstrate that kaempferol and kaempferide could attenuate OA-induced lipid accumulation and oxidative stress in HepG2 cells, which might benefit the treatment of NAFLD.

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