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.

Sequoyitol Alleviates High Glucose-Induced Inflammation, Oxidative Stress and Apoptosis of Retina Epithelial Cells

2021 ◽  
Vol 11 (5) ◽  
pp. 1003-1009
Author(s):  
Liping Hu ◽  
Rui Zhang ◽  
Jianhua Wu ◽  
Chao Feng ◽  
Li Kong
Keyword(s):  
Oxidative Stress ◽  
Protein Expression ◽  
Cell Viability ◽  
Inflammatory Cytokines ◽  
High Glucose ◽  
Cell Apoptosis ◽  
Therapeutic Potential ◽  
Promoting Effect ◽  
Related Factors ◽  
And Oxidative Stress

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes, contributing to visual impairment and blindness. Sequoyitol (Seq), a form of inositol derivatives, has been demonstrated to be a therapeutic potential for diabetes and diabetic nephropathy. The aim of this study is to explore the effects of Seq on DR. ARPE-19 cells were cultured in high glucose (HG) condition to simulate DR in vitro. Seq (1,10 and 20 µM) was applied for treatment. CCK-8 assay was performed to detect cell viability. Flow cytometry analysis was conducted to determine cell apoptosis rate. The production level of inflammatory cytokines and oxidative stress-related factors were determined using their commercial kits. The protein expressions of corresponding genes were detected using western blotting. The results revealed that Seq significantly increased cell viability and protein expression of PCNA and Ki67 which were decreased after HG induction. HG promoted cell apoptosis by decreasing protein expression of Bcl-2 and increasing protein expression of Bax and cleaved caspase-3, which was then reversed by Seq treatment. Besides, Seq abolished the promoting effects of HG on the production of pro-inflammatory cytokines and oxidative stress-related factors. Furthermore, Seq suppressed the promoting effect of HG on the activation of NF-κB signaling by inhibiting phosphorylation of kBa and NF-κB nucleus translocation. These results indicated that Seq might protect ARPE-19 cells against HG-induced cell viability, apoptosis, inflammation and oxidative stress by regulating NF-κB signaling, providing evidence for the potential application of Seq in the therapy of DR.

scholarly journals Intermittent High Glucose Enhances Apoptosis in INS-1 Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Xiao-li Shi ◽  
Yue-zhong Ren ◽  
Jing Wu
Keyword(s):  
Oxidative Stress ◽  
Beta Cells ◽  
High Glucose ◽  
Cell Apoptosis ◽  
Oxidative Stress Markers ◽  
Intracellular Level ◽  
High Concentration ◽  
Stress Markers ◽  
Intermittent High Glucose ◽  
And Oxidative Stress

To investigate the effect of intermittent high glucose (IHG) and sustained high glucose (SHG) on inducingβ-cell apoptosis and the potential involved mechanisms, INS-1 beta cells were incubated for 72 h in the medium containing different glucose concentrations: control (5.5 mmol/L), SHG (33.3 mmol/L), and IHG (5.5 mmol/L and 33.3 mmol/L glucose alternating every 12 h). Cell viability, apoptosis rate, and oxidative-stress markers were determined. The results showed that the apoptosis induced by IHG was more obvious than that by SHG. Simultaneously, the intracellular level of oxidative stress was more significantly increased in INS-1 cells exposed to IHG. These findings suggest that intermittent high glucose could be more deleterious toβ-cell than a constant high concentration of glucose, this may be due to the aggravation of oxidative stress triggered by intermittent high glucose.

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 Knockdown of long noncoding RNA HOTAIR inhibits osteoarthritis chondrocyte injury by miR-107/CXCL12 axis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jipeng Lu ◽  
Zhongxiong Wu ◽  
Ying Xiong
Keyword(s):  
Cell Proliferation ◽  
Western Blot ◽  
Cell Apoptosis ◽  
Noncoding Rna ◽  
Underlying Mechanism ◽  
Joint Disease ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Cxcl12 Expression ◽  
Ecm Degradation

Abstract Background Osteoarthritis (OA) is a joint disease characterized via destruction of cartilage. Chondrocyte damage is associated with cartilage destruction during OA. Long noncoding RNAs (lncRNAs) are implicated in the regulation of chondrocyte damage in OA progression. This study aims to investigate the role and underlying mechanism of lncRNA homeobox antisense intergenic RNA (HOTAIR) in OA chondrocyte injury. Methods Twenty-three OA patients and healthy controls without OA were recruited. Chondrocytes were isolated from OA cartilage tissues. HOTAIR, microRNA-107 (miR-107) and C-X-C motif chemokine ligand 12 (CXCL12) levels were measured by quantitative real-time polymerase chain reaction and western blot. Cell proliferation, apoptosis and extracellular matrix (ECM) degradation were measured using cell counting kit-8, flow cytometry and western blot. The target interaction was explored by bioinformatics, luciferase reporter and RNA immunoprecipitation assays. Results HOTAIR expression was enhanced, and miR-107 level was reduced in OA cartilage samples. HOTAIR overexpression inhibited cell proliferation, but induced cell apoptosis and ECM degradation in chondrocytes. HOTAIR knockdown caused an opposite effect. MiR-107 was sponged and inhibited via HOTAIR, and knockdown of miR-107 mitigated the effect of HOTAIR silence on chondrocyte injury. CXCL12 was targeted by miR-107. CXCL12 overexpression attenuated the roles of miR-107 overexpression or HOTAIR knockdown in the proliferation, apoptosis and ECM degradation. CXCL12 expression was decreased by HOTAIR silence, and restored by knockdown of miR-107. Conclusion HOTAIR knockdown promoted chondrocyte proliferation, but inhibited cell apoptosis and ECM degradation in OA chondrocytes by regulating the miR-107/CXCL12 axis.

Neuroprotection of chromobox 7 knockout in the mouse after cerebral ischemia-reperfusion injury via nuclear factor E2-related factor 2/hemeoxygenase-1 signaling pathway

2021 ◽  
pp. 096032712110361
Author(s):  
Hai-Tao Zhang ◽  
Xi-Zeng Wang ◽  
Qing-Mei Zhang ◽  
Han Zhao
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Infarct Size ◽  
Water Content ◽  
Cell Apoptosis ◽  
Ischemia Reperfusion ◽  
Related Factor ◽  
Nuclear Factor ◽  
Cerebral Ischemia Reperfusion ◽  
And Oxidative Stress

Objective To explore the mechanism of chromobox 7 (CBX7)-mediated nuclear factor E2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) signaling pathway in the cerebral ischemia/reperfusion (I/R) injury. Methods The experimental wild-type (WT) and CBX7-/- mice were used to establish cerebral I/R models using the middle cerebral artery occlusion (MCAO) surgery to determine CBX7 levels at different time points after MCAO injury. For all mice, neurological behavior, infarct size, water content, and oxidative stress–related indicators were determined, and transferase (TdT)-mediated dUTP-biotin nick-end labeling (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL)) staining method was employed to observe cell apoptosis, while Western blot to measure the expression of CBX7 and Nrf/HO-1 pathway-related proteins. Results At 6 h, 12 h, 24 h, 3 days, and 7 days after mice with MCAO, CBX7 expression was gradually up-regulated and the peak level was reached at 24 h. Mice in the WT + MCAO group had increased infarct size, with significant increases in the modified neurological severity scores and water content in the brain, as well as the quantity of TUNEL-positive cells. For the oxidative stress-indicators, an increase was seen in the content of MDA (malondial dehyde), but the activity of SOD (superoxide dismutase) and content of GSH-PX (glutathione peroxidase) and CAT (catalase) were decreased; meanwhile, the protein expression of CBX7, HO-1, and nuclear Nrf2 was up-regulated, while the cytoplasmic Nrf2 was down-regulated. Moreover, CBX7 knockout attenuated I/R injury in mice. Conclusion Knockout of CBX7 may protect mice from cerebral I/R injury by reducing cell apoptosis and oxidative stress, possibly via activating the Nrf2/HO-1 pathway.

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