scholarly journals Exosomal circEhmt1 Released from Hypoxia-Pretreated Pericytes Regulates High Glucose-Induced Microvascular Dysfunction via the NFIA/NLRP3 Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Lin Ye ◽  
Hui Guo ◽  
Yuan Wang ◽  
Yun Peng ◽  
Yongxin Zhang ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
High Glucose ◽  
Critical Role ◽  
Microvascular Dysfunction ◽  
Hypoxic Conditions ◽  
Dna Binding Site ◽  
Hif Pathway ◽  
Exosomal Rnas

Diabetic retinopathy (DR) is a frequently occurring microvascular complication induced by long-term hyperglycemia. Pericyte-endothelial cell crosstalk is critical for maintaining vascular homeostasis and remodeling; however, the molecular mechanism underlying that crosstalk remains unknown. In this study, we explored the crosstalk that occurs between endothelial cells and pericytes in response to diabetic retinopathy. Pericytes were stimulated with cobalt chloride (CoCl2) to activate the HIF pathway. Hypoxia-stimulated pericytes were cocultured with high glucose- (HG-) induced endotheliocytes. Cell viability was determined using the CCK-8 assay. Western blot studies were performed to detect the expression of proteins associated with apoptosis, hypoxia, and inflammation. ELISA assays were conducted to analyze the release of IL-1β and IL-18. We performed a circRNA microarray analysis of exosomal RNAs expressed under normoxic or hypoxic conditions. A FISH assay was performed to identify the location of circEhmt1 in pericytes. Chromatin immunoprecipitation (CHIP) was used to identify the specific DNA-binding site on the NFIA-NLRP3 complex. We found that pericyte survival was negatively correlated with the angiogenesis activity of endotheliocytes. We also found that hypoxia upregulated circEhmt1 expression in pericytes, and circEhmt1 could be transferred from pericytes to endotheliocytes via exosomes. Moreover, circEhmt1 overexpression protected endotheliocytes against HG-induced injury in vitro. Mechanistically, circEhmt1 was highly expressed in the nucleus of pericytes and could upregulate the levels of NFIA (a transcription factor) to suppress NLRP3-mediated inflammasome formation. Our study revealed a critical role for circEhmt1-mediated NFIA/NLRP3 signaling in retinal microvascular dysfunction and suggests that signaling pathway as a target for treating DR.

scholarly journals Protective Effects ofPanax notoginsengSaponins against High Glucose-Induced Oxidative Injury in Rat Retinal Capillary Endothelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yue Fan ◽  
Yuan Qiao ◽  
Jianmei Huang ◽  
Minke Tang
Keyword(s):  
Endothelial Cells ◽  
Diabetic Retinopathy ◽  
High Glucose ◽  
Microvascular Dysfunction ◽  
Panax Notoginseng ◽  
Protective Effects ◽  
Pronounced Increase ◽  
Nadph Oxidase 4 ◽  
Retinal Capillary ◽  
Capillary Endothelial Cells

Diabetic retinopathy, a leading cause of visual loss and blindness, is characterized by microvascular dysfunction. Hyperglycemia is considered the major pathogenic factor for diabetic retinopathy and is associated with increased oxidative stress in the retina. In this study, we investigated the potential protective effects ofPanax notoginsengSaponins (PNS) in retinal capillary endothelial cells (RCECs) exposed to high glucose conditions. We found a pronounced increase in cell viability in rat RCECs incubated with both PNS and high glucose (30 mM) for 48 h or 72 h. The increased viability was accompanied by reduced intracellular hydrogen peroxide (H2O2) and superoxide (O2-), decreased mitochondrial reactive oxygen species (ROS), and lowered malondialdehyde (MDA) levels. PNS also increased the activities of total superoxide dismutase (SOD), MnSOD, catalase (CAT), and glutathione peroxidase (GSH-PX). The glutathione (GSH) content also increased after PNS treatment. Furthermore, PNS reduced NADPH oxidase 4 (Nox4) expression. These results indicate that PNS exerts a protective effect against high glucose-induced injury in RCECs, which may be partially attributed to its antioxidative function.

scholarly journals Hypoxia Alters the Expression of Dipeptidyl Peptidase 4 and Induces Developmental Remodeling of Human Preadipocytes

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Helena H. Chowdhury ◽  
Jelena Velebit ◽  
Nataša Radić ◽  
Vito Frančič ◽  
Marko Kreft ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Transmembrane Protein ◽  
Human Adipose Tissue ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase 4 ◽  
Hypoxic Conditions ◽  
Human Preadipocytes ◽  
Developmental Remodeling

Dipeptidyl peptidase 4 (DPP4), a transmembrane protein, has been identified in human adipose tissue and is considered to be associated with obesity-related type 2 diabetes. Since adipose tissue is relatively hypoxic in obese participants, we investigated the expression of DPP4 in human preadipocytes (hPA) and adipocytes in hypoxia, during differentiation and upon insulin stimulation. The results show that DPP4 is abundantly expressed in hPA but very sparsely in adipocytes. During differentiationin vitro, the expression of DPP4 in hPA is reduced on the addition of differentiation medium, indicating that this protein can be hPA marker. Long term hypoxia altered the expression of DPP4 in hPA. Inin vitrohypoxic conditions the protease activity of shed DPP4 is reduced; however, in the presence of insulin, the increase in DPP4 expression is potentiated by hypoxia.

Long non-coding RNA SNHG16 regulates E2F1 expression by sponging miR-20a-5p and aggravating proliferative diabetic retinopathy

2021 ◽  
Author(s):  
Xiaohua Li ◽  
Chenyu Guo ◽  
Yong Chen ◽  
Feifei Yu
Keyword(s):  
Diabetic Retinopathy ◽  
Microvascular Dysfunction ◽  
Luciferase Reporter ◽  
Non Coding Rna ◽  
Reporter Assays ◽  
Polymerase Chain ◽  
Long Non Coding Rna ◽  
E2f1 Expression

Long non-coding RNAs (lncRNAs) were reported that related to microvascular dysfunction in diabetic retinopathy (DR), but the potential mechanism remains unknown. This study was designed to elucidate the effects of lncRNA SNHG16 in proliferative DR progression. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to measure the levels of SNHG16 and miR-20a-5p from peripheral blood samples of different participants. Pearson’s correlation analysis on the plasma data was applied to detect correlations between SNHG16 and miR-20a-5p. Finally, the interactions of miR-20a-5p and SNHG16 or E2F1 were assessed by luciferase reporter assays. SNHG16 and E2F1 were increased and miR-20a-5p was decreased in proliferative DR both in vivo and in vitro, when compared with control or non-proliferative DR. E2F1 was identified as the target of miR-20a-5p. MiR-20a-5p interacted with SNHG16 and E2F1, and was controlled by SNHG16. The regulation of SNHG16 on E2F1 was mediated by miR-20a-5p. Cells transfected with SNHG16 OE plasmid markedly increased cell apoptosis and vessel-like formation, whereas the miR-20a-5p mimic partially reversed these effects. Transfection with si-E2F1 plasmid rescued SNHG16 overexpression-aggravated proliferative DR. This study indicated that SNHG16 regulated E2F1 expression by sponging miR-20a-5p and aggravating proliferative DR.

scholarly journals Kinetics of sickle cell biorheology and implications for painful vasoocclusive crisis

2015 ◽  
Vol 112 (5) ◽  
pp. 1422-1427 ◽  
Author(s):  
E Du ◽  
Monica Diez-Silva ◽  
Gregory J. Kato ◽  
Ming Dao ◽  
Subra Suresh
Keyword(s):  
Disease Severity ◽  
Cell Density ◽  
Sickle Cell ◽  
Hematological Parameters ◽  
Diagnostic Tools ◽  
Hypoxic Conditions ◽  
Vitro Model ◽  
Kinetics Of

We developed a microfluidics-based model to quantify cell-level processes modulating the pathophysiology of sickle cell disease (SCD). This in vitro model enabled quantitative investigations of the kinetics of cell sickling, unsickling, and cell rheology. We created short-term and long-term hypoxic conditions to simulate normal and retarded transit scenarios in microvasculature. Using blood samples from 25 SCD patients with sickle hemoglobin (HbS) levels varying from 64 to 90.1%, we investigated how cell biophysical alterations during blood flow correlated with hematological parameters, HbS level, and hydroxyurea (HU) therapy. From these measurements, we identified two severe cases of SCD that were also independently validated as severe from a genotype-based disease severity classification. These results point to the potential of this method as a diagnostic indicator of disease severity. In addition, we investigated the role of cell density in the kinetics of cell sickling. We observed an effect of HU therapy mainly in relatively dense cell populations, and that the sickled fraction increased with cell density. These results lend support to the possibility that the microfluidic platform developed here offers a unique and quantitative approach to assess the kinetic, rheological, and hematological factors involved in vasoocclusive events associated with SCD and to develop alternative diagnostic tools for disease severity to supplement other methods. Such insights may also lead to a better understanding of the pathogenic basis and mechanism of drug response in SCD.

scholarly journals Vascular Endothelial Growth Factor Is Essential for Hyperglycemia-Induced Structural and Functional Alterations of the Peritoneal Membrane

2001 ◽  
Vol 12 (8) ◽  
pp. 1734-1741 ◽  
Author(s):  
AN S. DE VRIESE ◽  
RONALD G. TILTON ◽  
CLIFFORD C. STEPHAN ◽  
NORBERT H. LAMEIRE
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
High Glucose ◽  
Microvascular Dysfunction ◽  
Vascular Endothelial ◽  
Peritoneal Membrane ◽  
Long Term Treatment ◽  
Glucose Exposure ◽  
Endothelial Growth Factor

Abstract. Long-term peritoneal dialysis is associated with the development of functional and structural alterations of the peritoneal membrane. Long-term exposure to the high glucose concentrations in conventional peritoneal dialysate has been implicated in the pathogenesis of peritoneal hyperpermeability and neoangiogenesis. Vascular endothelial growth factor (VEGF) is an endothelial-specific growth factor that potently stimulates microvascular permeability and proliferation. High glucose exposure upregulates VEGF expression in various cell types and tissues. This study investigated whether VEGF plays a pathogenetic role in hyperglycemia-induced microvascular dysfunction in the peritoneal membrane. The peritoneal microcirculation of streptozotocin-induced diabetic rats and age-matched controls was studiedin vivowith a combination of functional and morphologic techniques. The diabetic microcirculation was characterized by an elevated transport of small solutes, indicating the presence of an increased effective vascular surface area. The leakage of FITC-albumin was more rapid in diabetic vessels, suggesting hyperpermeability for macromolecules. Structurally, an increased vascular density with focal areas of irregular capillary budding was found in the diabetic peritoneum. The hyperglycemia-induced structural and functional microvascular alterations were prevented by long-term treatment with neutralizing anti-VEGF monoclonal antibodies, whereas treatment with isotype-matched control antibodies had no effect. VEGF blockade did not influence microvascular density or macromolecular leakage in control rats, demonstrating specificity for the hyperglycemia-induced alterations. The present results thus support an causative link among high glucose exposure, upregulation of VEGF, and peritoneal microvascular dysfunction.

scholarly journals PKCδPromotes High Glucose Induced Renal Tubular Oxidative Damage via Regulating Activation and Translocation of p66Shc

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Panai Song ◽  
Shikun Yang ◽  
Li Xiao ◽  
Xiaoxuan Xu ◽  
Chengyuan Tang ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
High Glucose ◽  
Cell Injury ◽  
Critical Role ◽  
Dependent Manner ◽  
Ros Production ◽  
Tubular Injury ◽  
Renal Tubular ◽  
Stage Renal Disease

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease (ESRD). Renal tubular injury by overproduction of ROS in mitochondria plays a critical role in the pathogenesis of DKD. Evidences have shown that p66Shc was involved in renal tubular injury via mitochondrial-dependent ROS production pathway, but little is known about the upstream signaling of p66Shc that leads to tubular oxidative damage under high glucose conditions. In this study, an increased PKCδand p66Shc activation and ROS production in renal tissues of patients with diabetic nephropathy were seen and further analysis revealed a positive correlation between the tubulointerstitial damage and p-PKCδ, p-p66Shc, and ROS production. In vitro, we investigated the phosphorylation and activation of p66Shc and PKCδduring treatment of HK-2 cells with high glucose (HG). Results showed that the activation of p66Shc and PKCδwas increased in a dose- and time-dependent manner, and this effect was suppressed by Rottlerin, a pharmacologic inhibitor of PKCδ. Moreover, PKCδsiRNA partially blocked HG-induced p66Shc phosphorylation, translocation, and ROS production in HK-2 cells. Taken together, these data suggest that activation of PKCδpromotes tubular cell injury through regulating p66Shc phosphorylation and mitochondrial translocation in HG ambient.

scholarly journals Potential Combination Drug Therapy to Prevent Redox Stress and Mitophagy Dysregulation in Retinal Müller Cells under High Glucose Conditions: Implications for Diabetic Retinopathy

Diseases ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 91
Author(s):  
Lalit Pukhrambam Singh ◽  
Takhellambam S. Devi
Keyword(s):  
Transcription Factor ◽  
Diabetic Retinopathy ◽  
Drug Treatment ◽  
Combination Treatment ◽  
High Glucose ◽  
Drug Combination ◽  
Redox Stress ◽  
Combination Drug ◽  
Mitochondrial Stress

Chronic hyperglycemia-induced thioredoxin-interacting protein (TXNIP) expression, associated oxidative/nitrosative stress (ROS/RNS), and mitochondrial dysfunction play critical roles in the etiology of diabetic retinopathy (DR). However, there is no effective drug treatment to prevent or slow down the progression of DR. The purpose of this study is to examine if a combination drug treatment targeting TXNIP and the mitochondria-lysosome pathway prevents high glucose-induced mitochondrial stress and mitophagic flux in retinal Müller glial cells in culture, relevant to DR. We show that diabetes induces TXNIP expression, redox stress, and Müller glia activation (gliosis) in rat retinas when compared to non-diabetic rat retinas. Furthermore, high glucose (HG, 25 mM versus low glucose, LG 5.5 mM) also induces TXNIP expression and mitochondrial stress in a rat retinal Müller cell line, rMC1, in in vitro cultures. Additionally, we develop a mitochondria-targeted mCherry and EGFP probe tagged with two tandem COX8a mitochondrial target sequences (adenovirus-CMV-2×mt8a-CG) to examine mitophagic flux in rMC1. A triple drug combination treatment was applied using TXNIP-IN1 (which inhibits TXNIP interaction with thioredoxin), Mito-Tempo (mitochondrial anti-oxidant), and ML-SA1 (lysosome targeted activator of transient calcium channel MCOLN1/TRPML1 and of transcription factor TFEB) to study the mitochondrial–lysosomal axis dysregulation. We found that HG induces TXNIP expression, redox stress, and mitophagic flux in rMC1 versus LG. Treatment with the triple drug combination prevents mitophagic flux and restores transcription factor TFEB and PGC1α nuclear localization under HG, which is critical for lysosome biosynthesis and mitogenesis, respectively. Our results demonstrate that 2×mt8a-CG is a suitable probe for monitoring mitophagic flux, both in live and fixed cells in in vitro experiments, which may also be applicable to in vivo animal studies, and that the triple drug combination treatment has the potential for preventing retinal injury and disease progression in diabetes.

scholarly journals Tofacitinib Ameliorates Retinal Vascular Leakage in a Murine Model of Diabetic Retinopathy with Type 2 Diabetes

2021 ◽  
Vol 22 (21) ◽  
pp. 11876
Author(s):  
Eimear M. Byrne ◽  
María Llorián-Salvador ◽  
Timothy J. Lyons ◽  
Mei Chen ◽  
Heping Xu
Keyword(s):  
Type 2 Diabetes ◽  
Diabetic Retinopathy ◽  
High Glucose ◽  
Macular Oedema ◽  
Diabetic Macular Oedema ◽  
Janus Kinase ◽  
Blood Retinal Barrier ◽  
Albumin Leakage

We have previously reported that inhibition of the Janus kinase 1 (JAK1) signaling ameliorates IL-17A-mediated blood-retinal barrier (BRB) dysfunction. Higher levels of IL-17A have been observed in the blood and intraocular fluids in patients with diabetic retinopathy (DR), in particular those with diabetic macular oedema. This study aimed to understand whether JAK1 inhibition could prevent BRB dysfunction in db/db mice, a model of type 2 diabetes (T2D). An in vitro study showed that high glucose treatment disrupted the junctional distribution of claudin-5 in bEnd3 cells and ZO-1 in ARPE19 cells and that tofacitinib citrate treatment prevented high glucose-mediated tight junction disruption. Albumin leakage, accompanied by increased levels of the phosphorylated form of JAK1 (pJAK1), was observed in three-month-old db/db mice. Treatment of two-and-a-half-month-old db/db mice with tofacitinib citrate for two weeks significantly reduced retinal albumin leakage and reduced pJAK1 expression. pJAK1 expression was also detected in human DR retina. Our results suggest that JAK1 inhibition can ameliorate BRB dysfunction in T2D, and JAK1 inhibitors such as tofacitinib citrate may be re-purposed for the management of diabetic macular oedema.

scholarly journals The Expression and Significance of mTORC1 in Diabetic Retinopathy

2019 ◽  
Author(s):  
Yanli Liu ◽  
Yarong Zheng ◽  
Yekai Zhou ◽  
Yi Liu ◽  
Mengjuan Xie ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Diabetic Retinopathy ◽  
Western Blotting ◽  
Rat Model ◽  
High Glucose ◽  
Control Group ◽  
Diabetes Group ◽  
And Migration ◽  
Proliferation And Migration

Abstract Background: To investigate the expression and significance of mechanistic target of rapamycin complex 1(mTORC1) in diabetic retinopathy(DR), and to find new targets and new methods for the treatment of DR.Methods: A DR rat model was prepared by general feeding combined with intraperitoneal injection of 10% streptozotocin (60 mg/kg). The rats were randomly divided into a control group (NDM group) and diabetes group (DM group).Three months later,the degrees of retinopathy were determined using hematoxylin and eosin staining,and the levels of p-S6, VEGF, and PEDF proteins were detected by immunohistochemistry and western blotting. Human retinal capillary endothelial cells (HRCECs) were cultured in high glucose conditions,then treated with rapamycin or transfected with siTSC1.The protein levels of p-S6 were assessed by western blotting. The 5-ethynyl-2´-deoxyuridine assay was used to detect cell proliferation, and the Transwell assay was used to detect cell migration.Results: A DM rat model was successfully developed. The expressions of p-S6 and VEGF proteins were significantly increased in the DM group (p < 0.05), and the expression of PEDF protein was significantly decreased compared with the control group (p < 0.05). In vitro,the p-S6 protein in high glucose(HG) induced HRCECs was increased compared with the normal control (p < 0.05), and cell proliferation and migration were increased compared with the normal glucose(NG) group (p < 0.05). After transfection with siTSC1 to activate mTORC1,the expression of p-S6 was increased,as well as cell proliferation and migration.In contrast rapamycin decreased p-S6 expression in HG induced HRCECs, as well as decrased proliferation and migration (p < 0.05).Conclusion: The mTORC1 played an important role in DR. After activation, mTORC1 induced expression of the p-S6 protein, regulated the expressions of VEGF and PEDF proteins, and changed the proliferation and migration of endothelial cells.The mTORC1 can therefore be used as a new target,as well as in the treatment of DR.

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