scholarly journals 670nm photobiomodulation modulates bioenergetics and oxidative stress, in rat Müller cells challenged with high glucose

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260968
Author(s):  
Hannah J. Nonarath ◽  
Alexandria E. Hall ◽  
Gopika SenthilKumar ◽  
Betsy Abroe ◽  
Janis T. Eells ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Glial Cells ◽  
High Glucose ◽  
Near Infrared ◽  
Müller Cells ◽  
Model System ◽  
Light Treatment ◽  
Muller Cells ◽  
Müller Glial Cells

Diabetic retinopathy (DR), the most common complication of diabetes mellitus, is associated with oxidative stress, nuclear factor-κB (NFκB) activation, and excess production of vascular endothelial growth factor (VEGF) and intracellular adhesion molecule-1 (ICAM-1). Muller glial cells, spanning the entirety of the retina, are involved in DR inflammation. Mitigation of DR pathology currently occurs via invasive, frequently ineffective therapies which can cause adverse effects. The application of far-red to near-infrared (NIR) light (630-1000nm) reduces oxidative stress and inflammation in vitro and in vivo. Thus, we hypothesize that 670nm light treatment will diminish oxidative stress preventing downstream inflammatory mechanisms associated with DR initiated by Muller cells. In this study, we used an in vitro model system of rat Müller glial cells grown under normal (5 mM) or high (25 mM) glucose conditions and treated with a 670 nm light emitting diode array (LED) (4.5 J/cm2) or no light (sham) daily. We report that a single 670 nm light treatment diminished reactive oxygen species (ROS) production and preserved mitochondrial integrity in this in vitro model of early DR. Furthermore, treatment for 3 days in culture reduced NFκB activity to levels observed in normal glucose and prevented the subsequent increase in ICAM-1. The ability of 670nm light treatment to prevent early molecular changes in this in vitro high glucose model system suggests light treatment could mitigate early deleterious effects modulating inflammatory signaling and diminishing oxidative stress.

scholarly journals Metabolic Imbalance Effect on Retinal Müller Glial Cells Reprogramming Capacity: Involvement of Histone Deacetylase SIRT6

2021 ◽  
Vol 12 ◽  
Author(s):  
L Francisco Sanhueza Salas ◽  
Alfredo García-Venzor ◽  
Natalia Beltramone ◽  
Claudia Capurro ◽  
Debra Toiber ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Histone Deacetylase ◽  
Glial Cells ◽  
High Glucose ◽  
Müller Cells ◽  
Enrichment Analysis ◽  
Regulatory Elements ◽  
Muller Cells ◽  
Müller Glial Cells ◽  
And Oxidative Stress

Retinal Müller glial cells (MGs) are among the first to demonstrate metabolic changes during retinal disease and are a potential source of regenerative cells. In response to a harmful stimulus, they can dedifferentiate acquiring neural stem cells properties, proliferate and migrate to the damaged retinal layer and differentiate into lost neurons. However, it is not yet known how this reprogramming process is regulated in mammals. Since glucose and oxygen are important regulatory elements that may help directing stem cell fate, we aimed to study the effect of glucose variations and oxidative stress in Müller cells reprogramming capacity and analyze the participation the histone deacetylase SIRT6, as an epigenetic modulator of this process. We found that the combination of high glucose and oxidative stress induced a decrease in the levels of the marker glutamine synthetase, and an increase in the migration capacity of the cells suggesting that these experimental conditions could induce some degree of dedifferentiation and favor the migration ability. High glucose induced an increase in the levels of the pluripotent factor SOX9 and a decrease in SIRT6 levels accompanied by the increase in the acetylation levels of H3K9. Inhibiting SIRT6 expression by siRNA rendered an increase in SOX9 levels. We also determined SOX9 levels in retinas from mice with a conditional deletion of SIRT6 in the CNS. To further understand the mechanisms that regulate MGs response under metabolic impaired conditions, we evaluated the gene expression profile and performed Gene Ontology enrichment analysis of Müller cells from a murine model of Diabetes. We found several differentially expressed genes and observed that the transcriptomic change involved the enrichment of genes associated with glucose metabolism, cell migration, development and pluripotency. We found that many functional categories affected in cells of diabetic animals were directly related to SIRT6 function. Transcription factors enrichment analysis allowed us to predict several factors, including SOX9, that may be involved in the modulation of the differential expression program observed in diabetic MGs. Our results underline the heterogeneity of Müller cells response and the challenge that the study of metabolic impairment in vivo represents.

scholarly journals 670nm Photobiomodulation Modulates Bioenergetics And Oxidative Stress, Decreasing Inflammatory Mediator Production In An In Vitro Model Of Diabetic Retinopathy

2021 ◽  
Author(s):  
Hannah J. Nonarath ◽  
Alexandria E. Hall ◽  
Gopika SenthilKumar ◽  
Betsy Abroe ◽  
Janis T. Eells ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Retinopathy ◽  
Near Infrared ◽  
Therapeutic Option ◽  
Model System ◽  
Light Treatment ◽  
Subsequent Increase ◽  
Atp Production

Abstract Diabetic retinopathy (DR), the most common complication of diabetes mellitus, is associated with oxidative stress, nuclear factor-kB (NFkB) activation, and excess production of vascular endothelial growth factor (VEGF) and intracellular adhesion molecule-1 (ICAM-1). Current therapies are invasive, frequently ineffective, and have adverse effects. The application of far-red to near-infrared (NIR) light (630-1000nm) reduces oxidative stress and inflammation in vitro and in vivo. Thus, we hypothesize that 670nm light treatment will dimish oxidative stress preventing downstream inflammatory mechanisms associated with DR. We used an in vitro model system of rat Müller glial cells grown under normal (5 mM) or high (25 mM) glucose conditions and treated with a 670 nm light emitting diode array (LED) (4.5 J/cm2) or no light (sham) daily. We report that a single 670 nm light treatment diminished ROS production and preserved mitochondrial integrity and ATP production in this in vitro model of diabetic retinopathy. Furthermore, treatment for 3 days in culture reduced NFkB activity to levels observed in normal glucose and prevented the subsequent increase in ICAM-1. The ability of 670nm light treatment to prevent early molecular changes in this established DR model system suggests light treatment could become an early therapeutic option for DR.

scholarly journals Dietary Supplement Enriched in Antioxidants and Omega-3 Promotes Glutamine Synthesis in Müller Cells: A Key Process against Oxidative Stress in Retina

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3216
Author(s):  
Maryvonne Ardourel ◽  
Chloé Felgerolle ◽  
Arnaud Pâris ◽  
Niyazi Acar ◽  
Khaoula Ramchani Ben Othman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Müller Cells ◽  
Nutritional Supplement ◽  
Glutamine Metabolism ◽  
Muller Cells ◽  
Omega 3 ◽  
Glutamine Synthesis ◽  
The Impact

To prevent ocular pathologies, new generation of dietary supplements have been commercially available. They consist of nutritional supplement mixing components known to provide antioxidative properties, such as unsaturated fatty acid, resveratrol or flavonoids. However, to date, only one preclinical study has evaluated the impact of a mixture mainly composed of those components (Nutrof Total®) on the retina and demonstrated that in vivo supplementation prevents the retina from structural and functional injuries induced by light. Considering the crucial role played by the glial Müller cells in the retina, particularly to regulate the glutamate cycle to prevent damage in oxidative stress conditions, we questioned the impact of this ocular supplement on the glutamate metabolic cycle. To this end, various molecular aspects associated with the glutamate/glutamine metabolism cycle in Müller cells were investigated on primary Müller cells cultures incubated, or not, with the commercially mix supplement before being subjected, or not, to oxidative conditions. Our results demonstrated that in vitro supplementation provides guidance of the glutamate/glutamine cycle in favor of glutamine synthesis. These results suggest that glutamine synthesis is a crucial cellular process of retinal protection against oxidative damages and could be a key step in the previous in vivo beneficial results provided by the dietary supplementation.

scholarly journals Long non-coding RNA nuclear paraspeckle assembly transcript 1 inhibits the apoptosis of retina Müller cells after diabetic retinopathy through regulating miR-497/brain-derived neurotrophic factor axis

2018 ◽  
Vol 15 (3) ◽  
pp. 204-213 ◽  
Author(s):  
Xiu-juan Li
Keyword(s):  
Diabetes Mellitus ◽  
Diabetic Retinopathy ◽  
High Glucose ◽  
Neurotrophic Factor ◽  
Müller Cells ◽  
Brain Derived Neurotrophic Factor ◽  
Muller Cells ◽  
Non Coding Rna ◽  
Long Non Coding Rna

Background: The role of long non-coding RNA in diabetic retinopathy, a serious complication of diabetes mellitus, has attracted increasing attention in recent years. The purpose of this study was to explore whether long non-coding RNA nuclear paraspeckle assembly transcript 1 was involved in the context of diabetic retinopathy and its underlying mechanisms. Results: Our results revealed that nuclear paraspeckle assembly transcript 1 was significantly downregulated in the retina of diabetes mellitus rats. Meanwhile, miR-497 was significantly increased in diabetes mellitus rats’ retina and high glucose–treated Müller cells, but brain-derived neurotrophic factor was increased. We also found that high glucose–induced apoptosis of Müller cells was accompanied by the significant downregulation of nuclear paraspeckle assembly transcript 1 in vitro. Further study demonstrated that high glucose–promoted Müller cells apoptosis through downregulating nuclear paraspeckle assembly transcript 1 and downregulated nuclear paraspeckle assembly transcript 1 mediated this effect via negative regulating miR-497. Moreover, brain-derived neurotrophic factor was negatively regulated by miR-497 and associated with the apoptosis of Müller cells under high glucose. Conclusion: Our results suggested that under diabetic conditions, downregulated nuclear paraspeckle assembly transcript 1 decreased the expression of brain-derived neurotrophic factor through elevating miR-497, thereby promoting Müller cells apoptosis and aggravating diabetic retinopathy.

scholarly journals Unfolded Protein Response Pathways Correlatively Modulate Endoplasmic Reticulum Stress Responses in Rat Retinal Müller Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Shengyu Wu ◽  
Xiaolu Zhu ◽  
Biechuan Guo ◽  
Tian Zheng ◽  
Jiangbo Ren ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Endoplasmic Reticulum Stress ◽  
High Glucose ◽  
Müller Cells ◽  
Muller Cells ◽  
Unfolded Protein ◽  
Activating Transcription Factor ◽  
Protein Response

Background. Endoplasmic reticulum stress (ERS) in the retinal Müller cells is a key factor contributing to the retinal inflammation and vascular leakage in diabetic retinopathy (DR). This study was to investigate the underlying mechanisms through which the 3 main unfolded protein response (UPR) pathways regulate ERS and to examine the expression levels of vascular endothelial growth factor (VEGF) in Müller cells in vitro. Methods. Rat Müller cell lines were stimulated with high glucose to mimic a diabetic environment in vitro. PKR-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1) and activating transcription factor 6 (ATF6) were downregulated or upregulated with shRNA or overexpression plasmids. The transfected Müller cells were cultivated in high glucose medium for 48 hours. Expression of glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), X-box binding protein 1 (XBP1), ATF6, and VEGF was examined with immunofluorescence and western blot. Results. Our data indicated that ERS was found in both high glucose and osmotic control groups. Overexpression or downregulation of UPR pathways effectively increased or reduced the production of GRP78, ATF4, XBP1, ATF6, and VEGF, respectively. These 3 signaling pathways had similar regulatory effects on VEGF. Conclusion. The 3 UPR-mediated inflammatory pathways were dependent on each other. Inhibition any of these signaling pathways in UPR might be a potential therapeutic target for DR.

scholarly journals Geniposide Attenuates Hyperglycemia-Induced Oxidative Stress and Inflammation by Activating the Nrf2 Signaling Pathway in Experimental Diabetic Retinopathy

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yuanyuan Tu ◽  
Lele Li ◽  
Linling Zhu ◽  
Yang Guo ◽  
Shu Du ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Retinopathy ◽  
Signaling Pathway ◽  
Cell Activation ◽  
Müller Cells ◽  
In Vivo Model ◽  
Muller Cells ◽  
Nrf2 Signaling Pathway

Geniposide (GEN) is a natural antioxidant and anti-inflammatory product and plays an important role in the treatment of diabetes and diabetic complications. To explore the biological functions and mechanism of GEN in diabetic retinopathy (DR), we constructed the in vitro and in vivo model of DR by using primary cultured mouse retinal Müller cells and C57BL/6 mice, respectively. We found that GEN inhibited ROS accumulation, NF-κB activation, Müller cell activation, and inflammatory cytokine secretion both in vitro and in vivo, which is probably mediated through the Nrf2 pathway. Exendin (9-39) (EX-9), an antagonist of glucagon-like peptide-1 receptor (GLP-1R), abolished the protective effect of GEN on high glucose- (HG-) induced Müller cells. Additionally, GEN decreased hyperglycemia-induced damage to Müller cells and blood-retinal barrier in the retinas of mice with DR. We demonstrated that GEN was capable of protecting Müller cells and mice from HG-induced oxidative stress and inflammation, which is mostly dependent on the Nrf2 signaling pathway through GLP-1R. GEN may be an effective approach for the treatment of DR.

scholarly journals Purinergic regulation of high-glucose-induced caspase-1 activation in the rat retinal Müller cell line rMC-1

2011 ◽  
Vol 301 (5) ◽  
pp. C1213-C1223 ◽  
Author(s):  
Katherine E. Trueblood ◽  
Susanne Mohr ◽  
George R. Dubyak
Keyword(s):  
High Glucose ◽  
Müller Cells ◽  
Müller Cell ◽  
Muller Cells ◽  
Interacting Protein ◽  
Caspase 1 ◽  
Muller Cell ◽  
Stimulation Of

Chronic activation of proinflammatory caspase-1 in the retinas of diabetic animals and patients in vivo and retinal Müller cells in vitro is well documented. In this study we characterized how elevated glucose and extracellular purines contribute to the activation of caspase-1 in a cultured rat Müller cell (rMC-1) model. The ability of high glucose (25 mM, 24 h) to activate caspase-1 was attenuated by either apyrase, which metabolizes extracellular ATP to AMP, or adenosine deaminase (ADA), which metabolizes extracellular adenosine to inosine. This suggested that autocrine stimulation of ATP-sensing P2 receptors and adenosine-sensing P1 receptors may in part mediate the response to high glucose. Exogenous ATP, 5′- N-ethylcarboxamido-adenosine (NECA), a nonselective P1 receptor agonist, or forskolin (FSK) increased caspase-1 activity in rMC-1 cells cultured in control glucose (5 mM) medium. Accumulation of active caspase-1 was also increased by dipyridamole, which suppresses adenosine reuptake. High-glucose stimulation of caspase-1 was attenuated by suramin, a nonselective P2 antagonist, or A2 adenosine receptor antagonists, but not by antagonism of P2X7 ATP-gated ion channel receptors. Although high glucose increased P2X7 mRNA, neither P2X7 protein nor function was detected in rMC-1 cells. The increased caspase-1 activity stimulated by high glucose, FSK, NECA, or ATP was correlated with increased gene expression of caspase-1 and thioredoxin-interacting-protein (TXNIP). These findings support a novel role for autocrine P1 and P2 purinergic receptors coupled to cAMP signaling cascades and transcriptional induction of caspase-1 in mediating the high-glucose-induced activation of caspase-1 and secretion of IL-1β in a cell culture model of nonhematopoietic retinal Müller cells.

scholarly journals Physiological properties of retinal Müller glial cells from the cynomolgus monkey, Macaca fascicularis—a comparison to human Müller cells

2005 ◽  
Vol 45 (14) ◽  
pp. 1781-1791 ◽  
Author(s):  
Thomas Pannicke ◽  
Bernd Biedermann ◽  
Ortrud Uckermann ◽  
Michael Weick ◽  
Andreas Bringmann ◽  
...  
Keyword(s):  
Glial Cells ◽  
Cynomolgus Monkey ◽  
Macaca Fascicularis ◽  
Müller Cells ◽  
Muller Cells ◽  
Müller Glial Cells ◽  
Physiological Properties

scholarly journals Extracellular H+ fluxes from tiger salamander Müller (glial) cells measured using self-referencing H+-selective microelectrodes

2017 ◽  
Vol 118 (6) ◽  
pp. 3132-3143 ◽  
Author(s):  
Matthew A. Kreitzer ◽  
David Swygart ◽  
Meredith Osborn ◽  
Blair Skinner ◽  
Chad Heer ◽  
...  
Keyword(s):  
Glial Cells ◽  
Müller Cells ◽  
Bicarbonate Transport ◽  
Extracellular Potassium ◽  
Tiger Salamander ◽  
Muller Cells ◽  
Extracellular Acidification ◽  
Müller Glial Cells ◽  
Bicarbonate Transporter ◽  
Induced Changes

Self-referencing H+-selective electrodes were used to measure extracellular H+ fluxes from Müller (glial) cells isolated from the tiger salamander retina. A novel chamber enabled stable recordings using H+-selective microelectrodes in a self-referencing format using bicarbonate-based buffer solutions. A small basal H+ flux was observed from the end foot region of quiescent cells bathed in 24 mM bicarbonate-based solutions, and increasing extracellular potassium induced a dose-dependent increase in H+ flux. Barium at 6 mM also increased H+ flux. Potassium-induced extracellular acidifications were abolished when bicarbonate was replaced by 1 mM HEPES. The carbonic anhydrase antagonist benzolamide potentiated the potassium-induced extracellular acidification, while 300 μM DIDS, 300 μM SITS, and 30 μM S0859 significantly reduced the response. Potassium-induced extracellular acidifications persisted in solutions lacking extracellular calcium, although potassium-induced changes in intracellular calcium monitored with Oregon Green were abolished. Exchange of external sodium with choline also eliminated the potassium-induced extracellular acidification. Removal of extracellular sodium by itself induced a transient alkalinization, and replacement of sodium induced a transient acidification, both of which were blocked by 300 μM DIDS. Recordings at the apical portion of the cell showed smaller potassium-induced extracellular H+ fluxes, and removal of the end foot region further decreased the H+ flux, suggesting that the end foot was the major source of acidifications. These studies demonstrate that self-referencing H+-selective electrodes can be used to monitor H+ fluxes from retinal Müller cells in bicarbonate-based solutions and confirm the presence of a sodium-coupled bicarbonate transporter, the activity of which is largely restricted to the end foot of the cell. NEW & NOTEWORTHY The present study uses self-referencing H+-selective electrodes for the first time to measure H+ fluxes from Müller (glial) cells isolated from tiger salamander retina. These studies demonstrate bicarbonate transport as a potent regulator of extracellular levels of acidity around Müller cells and point toward a need for further studies aimed at addressing how such glial cell pH regulatory mechanisms may shape neuronal signaling.

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