scholarly journals Detection of Autophagy-Related Gene Expression by Conjunctival Impression Cytology in Age-Related Macular Degeneration

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 296
Author(s):  
Chih-Wen Shu ◽  
Youn-Shen Bee ◽  
Jiunn-Liang Chen ◽  
Chui-Lien Tsen ◽  
Wei-Lun Tsai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Cell Viability ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Autophagic Flux ◽  
Related Gene ◽  
Impression Cytology ◽  
Conjunctival Impression Cytology

Purpose: To investigate the association of autophagy-related gene expression with age-related macular degeneration (AMD). Methods: Patients with AMD were recruited for analysis by conjunctival impression cytology. mRNA was assessed by real-time polymerase chain reaction (RT-PCR) to evaluate whether the expression of 26 autophagy-related genes (ATGs) was correlated with AMD. Further studies on cell viability and autophagic flux in response to oxidative stress by H2O2 were performed in human retinal pigment epithelial (RPE) cell lines based on the results of impression cytology. Results: Both the neovascular AMD (nAMD) and polypoidal choroidal vasculopathy (PCV) groups had significantly higher mRNA levels of gamma-aminobutyric acid receptor-associated protein-like 1 (GABARAPL1) and microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B) than the control group, but there was no significant difference between these two groups. Age difference existed only in the AMD group. GABARAPL1 and MAP1LC3B mRNA expression increased significantly after acute oxidative stress in adult retinal pigment epithelial (ARPE-19) cells. Cell viability significantly increased and decreased in the cells harboring GABARAPL1 expression vector and silenced with siRNA against GABARAPL1, respectively, during short-term oxidative stress, whereas viability increased in the GABARAPL1-silenced cells after long-term oxidative stress. Silencing GABARAPL1 itself caused a reduction in autophagic flux under both short and long-term oxidative stress. Conclusion: Our study showed the possibility of assessing autophagy-related gene expression by conjunctival impression cytology. GABARAPL1 was significantly higher in AMD. Although an in vitro study showed an initial protective effect of autophagy, a cell viability study revealed the possibility of a harmful effect after long-term oxidative injury. The underlying mechanism or critical factors require further investigation.

scholarly journals Sulforaphane Enhances the Ability of Human Retinal Pigment Epithelial Cell against Oxidative Stress, and Its Effect on Gene Expression Profile Evaluated by Microarray Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Liang Ye ◽  
Ting Yu ◽  
Yanqun Li ◽  
Bingni Chen ◽  
Jinshun Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Microarray Analysis ◽  
Retinal Pigment Epithelial ◽  
Nuclear Translocation ◽  
Retinal Pigment ◽  
Regulation Of Gene Expression ◽  
Age Related Macular Degeneration ◽  
Rpe Cells ◽  
Pigment Epithelial

To gain further insights into the molecular basis of Sulforaphane (SF) mediated retinal pigment epithelial (RPE) 19 cell against oxidative stress, we investigated the effects of SF on the regulation of gene expression on a global scale and tested whether SF can endow RPE cells with the ability to resist apoptosis. The data revealed that after exposure to H2O2, RPE 19 cell viability was increased in the cells pretreated with SF compared to the cell not treated with SF. Microarray analysis revealed significant changes in the expression of 69 genes in RPE 19 cells after 6 hours of SF treatment. Based on the functional relevance, eight of the SF-responsive genes, that belong to antioxidant redox system, and inflammatory responsive factors were validated. The up-regulating translation of thioredoxin-1 (Trx1) and the nuclear translocation of Nuclear factor-like2 (Nrf2) were demonstrated by immunoblot analysis in SF treated RPE cells. Our data indicate that SF increases the ability of RPE 19 cell against oxidative stress through up-regulating antioxidative enzymes and down-regulating inflammatory mediators and chemokines. The results suggest that the antioxidant, SF, may be a valuable supplement for preventing and retarding the development of Age Related Macular Degeneration.

scholarly journals Oxidative stress-mediated TXNIP loss causes RPE dysfunction

2019 ◽  
Vol 51 (10) ◽  
pp. 1-13 ◽  
Author(s):  
Min Ji Cho ◽  
Sung-Jin Yoon ◽  
Wooil Kim ◽  
Jongjin Park ◽  
Jangwook Lee ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Function ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Common Factor ◽  
Age Related Macular Degeneration ◽  
Autophagic Flux ◽  
Blood Retinal Barrier ◽  
Rpe Cells ◽  
Age Related

Abstract The disruption of the retinal pigment epithelium (RPE), for example, through oxidative damage, is a common factor underlying age-related macular degeneration (AMD). Aberrant autophagy also contributes to AMD pathology, as autophagy maintains RPE homeostasis to ensure blood–retinal barrier (BRB) integrity and protect photoreceptors. Thioredoxin-interacting protein (TXNIP) promotes cellular oxidative stress by inhibiting thioredoxin reducing capacity and is in turn inversely regulated by reactive oxygen species levels; however, its role in oxidative stress-induced RPE cell dysfunction and the mechanistic link between TXNIP and autophagy are largely unknown. Here, we observed that TXNIP expression was rapidly downregulated in RPE cells under oxidative stress and that RPE cell proliferation was decreased. TXNIP knockdown demonstrated that the suppression of proliferation resulted from TXNIP depletion-induced autophagic flux, causing increased p53 activation via nuclear localization, which in turn enhanced AMPK phosphorylation and activation. Moreover, TXNIP downregulation further negatively impacted BRB integrity by disrupting RPE cell tight junctions and enhancing cell motility by phosphorylating, and thereby activating, Src kinase. Finally, we also revealed that TXNIP knockdown upregulated HIF-1α, leading to the enhanced secretion of VEGF from RPE cells and the stimulation of angiogenesis in cocultured human retinal microvascular endothelial cells. This suggests that the exposure of RPE cells to sustained oxidative stress may promote choroidal neovascularization, another AMD pathology. Together, these findings reveal three distinct mechanisms by which TXNIP downregulation disrupts RPE cell function and thereby exacerbates AMD pathogenesis. Accordingly, reinforcing or restoring BRB integrity by targeting TXNIP may serve as an effective therapeutic strategy for preventing or attenuating photoreceptor damage in AMD.

scholarly journals Essential Role of Thioredoxin 2 in Mitigating Oxidative Stress in Retinal Epithelial Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Eriko Sugano ◽  
Namie Murayama ◽  
Maki Takahashi ◽  
Kitako Tabata ◽  
Makoto Tamai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Cell Viability ◽  
Metabolic Activity ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Hsp70 Expression ◽  
Age Related ◽  
Shock Proteins ◽  
Thioredoxin 2

The retina is constantly subjected to oxidative stress, which is countered by potent antioxidative systems present in retinal pigment epithelial (RPE) cells. Disruption of these systems leads to the development of age-related macular degeneration. Thioredoxin 2 (Trx2) is a potent antioxidant, which acts directly on mitochondria. In the present study, oxidative stress was induced in the human RPE cell line (ARPE-19) using 4-hydroxynonenal (4-HNE) or C2-ceramide. The protective effect of Trx2 against oxidative stress was investigated by assessing cell viability, the kinetics of cell death, mitochondrial metabolic activity, and expression of heat shock proteins (Hsps) in Trx2-overexpressing cell lines generated by transfecting ARPE cells with an adeno-associated virus vector encoding Trx2. We show that overexpression of Trx2 reduced cell death induced by both agents when they were present in low concentrations. Moreover, early after the induction of oxidative stress Trx2 played a key role in the maintenance of the cell viability through upregulation of mitochondrial metabolic activity and inhibition of Hsp70 expression.

scholarly journals SLC7A11 Reduces Laser-Induced Choroidal Neovascularization by Inhibiting RPE Ferroptosis and VEGF Production

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaohuan Zhao ◽  
Min Gao ◽  
Jian Liang ◽  
Yuhong Chen ◽  
Yimin Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Cell Viability ◽  
Laser Treatment ◽  
Choroidal Neovascularization ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Related Factor ◽  
Rpe Cells ◽  
Age Related

In age-related macular degeneration (AMD), one of the principal sources of vascular endothelial growth factor (VEGF) is retinal pigment epithelium (RPE) cells under hypoxia or oxidative stress. Solute carrier family 7 member 11 (SLC7A11), a key component of cystine/glutamate transporter, regulates the level of cellular lipid peroxidation, and restrains ferroptosis. In our study, we assessed the role of SLC7A11 in laser-induced choroidal neovascularization (CNV) and explored the underlying mechanism. We established a mouse model of CNV to detect the expression level of SLC7A11 and VEGF during disease progression. We found the expression of the SLC7A11 protein in RPE cells peaked at 3 days after laser treatment, which was correlated with the expression of VEGF. Intraperitoneal injection of SLC7A11 inhibitor expanded the area of CNV. We examined functional proteins related to oxidative stress and Fe2+ and found laser-induced ferroptosis accompanied by increased Fe2+ content and GPX4 expression in the RPE-choroidal complex after laser treatment. We verified the expression of SLC7A11 in the ARPE19 cell line and the effects of its inhibitors on cell viability and lipid peroxidation in vitro. Application of SLC7A11 inhibitor and SLC7A11 knockdown increased the level of lipid peroxidation and reduced the cell viability of ARPE19 which can be rescued by ferroptosis inhibitors ferrostatin-1 (Fer-1) and liproxstatin-1 (Lip-1). Conversely, SLC7A11 overexpression induced resistance to erastin or RSL3-induced ferroptosis. Moreover, we tested the possible regulatory transcription factor NF-E2-related factor 2 (NRF2) of SLC7A11 by Western blot. Knock-down of NRF2 decreased the expression of SLC7A11. Our study suggests that SLC7A11 plays a key role in the laser-induced CNV model by protecting RPE cells from ferroptosis. SLC7A11 provides a new therapeutic target for neovascular AMD patients.

scholarly journals The CD36 Ligand-Promoted Autophagy Protects Retinal Pigment Epithelial Cells from Oxidative Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Marie-France Dorion ◽  
Mukandila Mulumba ◽  
Shuya Kasai ◽  
Ken Itoh ◽  
William D. Lubell ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Autophagic Flux ◽  
Cytoprotective Effect ◽  
Rpe Cells ◽  
Age Related ◽  
Cluster Of Differentiation

The retinal pigment epithelium (RPE) performs many functions that maintain photoreceptor health. Oxidative damage to the RPE is a critical component in the pathogenesis of eye diseases such as age-related macular degeneration (AMD). Ligands of the cluster of differentiation 36 (CD36) have previously preserved photoreceptor integrity in mouse models of AMD. The cytoprotective effect of the CD36 ligand MPE-001 on RPE cells has now been elucidated employing a model of oxidative stress. Sodium iodate (NaIO3) induced formation of reactive oxygen species and apoptosis in human RPE cells, which were decreased by MPE-001 without affecting antioxidant enzyme transcription. Immunoblotting and immunostaining assays showed a restorative effect of MPE-001 on the autophagic flux disrupted by NaIO3, which was associated with an increase in syntaxin 17-positive mature autophagosomes. The cytoprotective effect of MPE-001 was completely abolished by the autophagy inhibitors wortmannin and bafilomycin A1. In conclusion, we report for the first time an autophagy-dependent protection of RPE cells from oxidative stress by a CD36 ligand.

scholarly journals Gastrodin represses hydrogen peroxide-induced oxidative stress in retinal pigment epithelial cells through p38MAPK/iNOS pathway

2021 ◽  
Vol 13 (4) ◽  
pp. 24-30
Author(s):  
Xingli Zhou ◽  
Ximing Zhao
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Viability ◽  
Cell Apoptosis ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
B Cell Lymphoma ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Age Related

Elevated reactive oxygen species (ROS) induce oxidative damage in retinal pigment epithelium (RPE) and con-tribute to the development of age-related macular degeneration (AMD). Gastrodin plays an antioxidant role in distinct diseases, such as epilepsy, cerebral ischemia, Alzheimer’s disease, and cardiovascular diseases. However, the function of gastrodin in AMD remains unclear. Human RPE (ARPE-19) cells were incubated with 300 μM hydrogen peroxide (H2O2) for 24 hours. The results showed that H2O2 decreased cell viability and promoted the cell apoptosis of ARPE-19 cells. H2O2-induced ARPE-19 cells were then treated with different concentrations of gastrodin. Gastrodin increased cell viability of H2O2-induced ARPE-19 cells, suppressed the cell apoptosis of H2O2-induced ARPE-19 cells with reduced B-cell lymphoma (Bcl)-2 like protein (Bax), and enhanced Bcl-2. The levels of ROS were enhanced, malondialdehyde (MDA) was up-regulated, and superoxide dismutase (SOD) and glutathione (GSH) were down-regulated in H2O2-induced ARPE-19 cells. However, gastrodin reduced the lev-els of ROS and MDA and elevated SOD and GSH in H2O2-induced ARPE-19 cells. Furthermore, H2O2-induced increase of inducible nitric oxide synthase (iNOS) and p-p38 proteins in ARPE-19 was reversed by gastrodin. In conclusion, gastrodin exerted antiapoptotic and antioxidant capacities to protect against H2O2-induced oxidative stress in RPE, thereby acting as a potential agent for managing AMD.

scholarly journals Resvega Alleviates Hydroquinone-Induced Oxidative Stress in ARPE-19 Cells

2020 ◽  
Vol 21 (6) ◽  
pp. 2066 ◽  
Author(s):  
Niina Bhattarai ◽  
Eveliina Korhonen ◽  
Maija Toppila ◽  
Ali Koskela ◽  
Kai Kaarniranta ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Cigarette Smoke ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ros Production ◽  
Rpe Cells ◽  
Age Related ◽  
Dichlorofluorescin Diacetate

Retinal pigment epithelial (RPE) cells maintain homeostasis at the retina and they are under continuous oxidative stress. Cigarette smoke is a prominent environmental risk factor for age-related macular degeneration (AMD), which further increases the oxidant load in retinal tissues. In this study, we measured oxidative stress and inflammatory markers upon cigarette smoke-derived hydroquinone exposure on human ARPE-19 cells. In addition, we studied the effects of commercial Resvega product on hydroquinone-induced oxidative stress. Previously, it was observed that Resvega induces autophagy during impaired protein clearance in ARPE-19 cells, for which it has the potential to alleviate pro-inflammatory pathways. Cell viability was determined while using the lactate dehydrogenase (LDH) and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and the cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) production were measured using the 2′,7′-dichlorofluorescin diacetate (H2DCFDA) probe. Hydroquinone compromised the cell viability and increased ROS production in ARPE-19 cells. Resvega significantly improved cell viability upon hydroquinone exposure and reduced the release of interleukin (IL)-8 and monocytic chemoattractant protein (MCP)-1 from RPE cells. Resvega, N-acetyl-cysteine (NAC) and aminopyrrolidine-2,4-dicarboxylic acid (APDC) alleviated hydroquinone-induced ROS production in RPE cells. Collectively, our results indicate that hydroquinone induces cytotoxicity and increases oxidative stress through NADPH oxidase activity in RPE cells, and resveratrol-containing Resvega products prevent those adverse effects.

scholarly journals Hydrogen Sulfide Protects Retinal Pigment Epithelial Cells from Oxidative Stress-Induced Apoptosis and Affects Autophagy

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Liming Hu ◽  
Jia Guo ◽  
Li Zhou ◽  
Sen Zhu ◽  
Chunming Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Crucial Role ◽  
Retinal Pigment Epithelial ◽  
Cell Injury ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Pigment Epithelial ◽  
Age Related

Age-related macular degeneration (AMD) is a major cause of visual impairment and blindness among the elderly. AMD is characterized by retinal pigment epithelial (RPE) cell dysfunction. However, the pathogenesis of AMD is still unclear, and there is currently no effective treatment. Accumulated evidence indicates that oxidative stress and autophagy play a crucial role in the development of AMD. H2S is an antioxidant that can directly remove intracellular superoxide anions and hydrogen peroxide. The purpose of this study is to investigate the antioxidative effect of H2S in RPE cells and its role in autophagy. The results show that exogenous H2S (NaHS) pretreatment effectively reduces H2O2-induced oxidative stress, oxidative damage, apoptosis, and inflammation in ARPE-19 cells. NaHS pretreatment also decreased autophagy levels raised by H2O2, increased cell viability, and ameliorated cell morphological damage. Interestingly, the suppression of autophagy by its inhibitor 3-MA showed an increase of cell viability, amelioration of morphology, and a decrease of apoptosis. In summary, oxidative stress causes ARPE-19 cell injury by inducing cell autophagy. However exogenous H2S is shown to attenuate ARPE-19 cell injury, decrease apoptosis, and reduce the occurrence of autophagy-mediated by oxidative stress. These findings suggest that autophagy might play a crucial role in the development of AMD, and exogenous H2S has a potential value in the treatment of AMD.

scholarly journals Crosstalk between Long-Term Sublethal Oxidative Stress and Detrimental Inflammation as Potential Drivers for Age-Related Retinal Degeneration

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Age Related Macular Degeneration ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Nuclear Factor ◽  
Rpe Cells ◽  
Age Related ◽  
Oxidative Insult

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.

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