scholarly journals Phloroglucinol prevents albumin glycation as well as diminishes ROS production, glycooxidative damage, nitrosative stress and inflammation in hepatocytes treated with high glucose

2021 ◽  
Vol 142 ◽  
pp. 111958
Author(s):  
Krzysztof Drygalski ◽  
Eliza Fereniec ◽  
Anna Zalewska ◽  
Adam Krętowski ◽  
Małgorzata Żendzian-Piotrowska ◽  
...  
2021 ◽  
Vol 22 (9) ◽  
pp. 4604
Author(s):  
Giuliana Mannino ◽  
Anna Longo ◽  
Florinda Gennuso ◽  
Carmelina Daniela Anfuso ◽  
Gabriella Lupo ◽  
...  

A pericyte-like differentiation of human adipose-derived mesenchymal stem cells (ASCs) was tested in in vitro experiments for possible therapeutic applications in cases of diabetic retinopathy (DR) to replace irreversibly lost pericytes. For this purpose, pericyte-like ASCs were obtained after their growth in a specific pericyte medium. They were then cultured in high glucose conditions to mimic the altered microenvironment of a diabetic eye. Several parameters were monitored, especially those particularly affected by disease progression: cell proliferation, viability and migration ability; reactive oxygen species (ROS) production; inflammation-related cytokines and angiogenic factors. Overall, encouraging results were obtained. In fact, even after glucose addition, ASCs pre-cultured in the pericyte medium (pmASCs) showed high proliferation rate, viability and migration ability. A considerable increase in mRNA expression levels of the anti-inflammatory cytokines transforming growth factor-β1 (TGF-β1) and interleukin-10 (IL-10) was observed, associated with reduction in ROS production, and mRNA expression of pro-inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), and angiogenic factors. Finally, a pmASC-induced better organization of tube-like formation by retinal endothelial cells was observed in three-dimensional co-culture. The pericyte-like ASCs obtained in these experiments represent a valuable tool for the treatment of retinal damages occurring in diabetic patients.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Yanjuan Hou ◽  
Qian Wang ◽  
Baosheng Han ◽  
Yiliang Chen ◽  
Xi Qiao ◽  
...  

AbstractTubulointerstitial inflammation plays a key role in the pathogenesis of diabetic nephropathy (DN). Interleukin-1β (IL-1β) is the key proinflammatory cytokine associated with tubulointerstitial inflammation. The NLRP3 inflammasome regulates IL-1β activation and secretion. Reactive oxygen species (ROS) represents the main mediator of NLRP3 inflammasome activation. We previously reported that CD36, a class B scavenger receptor, mediates ROS production in DN. Here, we determined whether CD36 is involved in NLRP3 inflammasome activation and explored the underlying mechanisms. We observed that high glucose induced-NLRP3 inflammasome activation mediate IL-1β secretion, caspase-1 activation, and apoptosis in HK-2 cells. In addition, the levels of CD36, NLRP3, and IL-1β expression (protein and mRNA) were all significantly increased under high glucose conditions. CD36 knockdown resulted in decreased NLRP3 activation and IL-1β secretion. CD36 knockdown or the addition of MitoTempo significantly inhibited ROS production in HK-2 cells. CD36 overexpression enhanced NLRP3 activation, which was reduced by MitoTempo. High glucose levels induced a change in the metabolism of HK-2 cells from fatty acid oxidation (FAO) to glycolysis, which promoted mitochondrial ROS (mtROS) production after 72 h. CD36 knockdown increased the level of AMP-activated protein kinase (AMPK) activity and mitochondrial FAO, which was accompanied by the inhibition of NLRP3 and IL-1β. The in vivo experimental results indicate that an inhibition of CD36 could protect diabetic db/db mice from tubulointerstitial inflammation and tubular epithelial cell apoptosis. CD36 mediates mtROS production and NLRP3 inflammasome activation in db/db mice. CD36 inhibition upregulated the level of FAO-related enzymes and AMPK activity in db/db mice. These results suggest that NLRP3 inflammasome activation is mediated by CD36 in renal tubular epithelial cells in DN, which suppresses mitochondrial FAO and stimulates mtROS production.


Author(s):  
Aravind P ◽  
Sarojini R. Bulbule ◽  
Hemalatha N ◽  
Anushree G ◽  
Babu R.L ◽  
...  

Abstract Background Free radicals generated in the biological system bring about modifications in biological molecules causing damage to their structure and function. Identifying the damage caused by ROS and RNS is important to predict the pathway of apoptosis due to stress in PC12 cells. The first defense mechanisms against them are antioxidants which act in various pathways through important cellular organelles like the mitochondria and endoplasmic reticulum. Specific biomarkers like Gadd153 which is a marker for endoplasmic reticulum stress, Nrf2 which responds to the redox changes and translocates the antioxidant response elements, and Btg2 which is an antioxidant regulator have not been addressed in different stress conditions previously in PC12 cells. Therefore, the study was conducted to analyze the gene expression pattern (SOD, Catalase, Btg2, Gadd153, and Nrf2) and the protein expression pattern (iNOS and MnSOD) of the antioxidant stress markers in differential stress-induced PC12 cells. Peroxynitrite (1 μM), rotenone (1 μM), H2O2(100 mM), and high glucose (33 mM) were used to induce oxidative and nitrosative stress in PC12 cells. Results The results obtained suggested that rotenone-induced PC12 cells showed a significant increase in the expression of catalase, Btg2, and Gadd153 compared to the control. Peroxynitrite-induced PC12 cells showed higher expression of Btg2 compared to the control. H2O2 and high glucose showed lesser expression compared to the control in all stress marker genes. In contrast, the Nrf2 gene expression is downregulated in all the stress-induced PC12 cells compared to the control. Further, MnSOD and iNOS protein expression studies suggest that PC12 cells exhibit a selective downregulation. Lower protein expression of MnSOD and iNOS may be resulted due to the mitochondrial dysfunction in peroxynitrite-, high glucose-, and H2O2-treated cells, whereas rotenone-induced cells showed lower expression, which could be the result of a dysfunction of the endoplasmic reticulum. Conclusion Different stress inducers like rotenone, peroxynitrite, H2O2, and high glucose increase the NO and ROS. Btg2 and Gadd153 genes were upregulated in the stress-induced cells, whereas the Nrf2 was significantly downregulated in differential stress-induced PC12 cells. Further, antioxidant marker genes were differentially expressed with different stress inducers.


2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Qing Zhao ◽  
Futian Tang ◽  
Limei Shan ◽  
Inga Cepinskas ◽  
Gedas Cepinskas ◽  
...  

Objectives: Elevated levels of reactive oxygen species (ROS) are the initial source of endothelial dysfunction in diabetes. Calpain has been implicated in diabetic vascular complications. The present study was to investigate the role of calpain in mitochondrial ROS generation in endothelial cells and vascular dysfunction in diabetic mice. Methods: Endothelial cells cultured from human umbilical vein (HUVEC) were stimulated with high glucose. Calpain activity and protein were determined in mitochondria of HUVEC. Intracellular and mitochondrial ROS generation as well as apoptosis were measured. Type I diabetic OVE 26 mice and type II diabetic db/db mice with calpastatin over-expression (OVE26/CAST and db/db-CAST) were generated, respectively. Type I diabetes was also induced in both wild-type and Tg-CAST mice by injection of streptozocin (STZ). The endothelium-dependent relaxation of aortic ring was measured. Results: High glucose significantly increased calpain-1 protein, calpain activity and ROS generation in mitochondria of HUVEC. Pharmacological inhibition of calpain or over-expression of calpastatin abrogated high glucose-induced intracellular ROS production, mitochondrial ROS generation and apoptosis in HUVEC. Incubation of isolated mitochondria with calpain-1 protein significantly induced its ROS generation and the membrane potential. In diabetic mice, calpain activity was induced in aortic vessels, which correlated with an increase in ROS production and protein tyrosine nitration. Over-expression of calpastatin prevented calpain activity, reduced ROS production and inhibited protein tyrosine nitration in diabetic mice. Aortic ring segments from diabetic mice exhibited a significant reduction in vascular relaxation to acetylcholine, which was reversed by over-expression of calpastatin in Tg-CAST, OVE26/CAST and db/db-CAST mice. Conclusions: This study has demonstrated a novel role of calpain in mitochondrial ROS generation, which contributes to apoptosis in endothelial cells during hyperglycemia. Thus, over-expression of calpastatin inhibits reduces ROS production and ameliorates endothelium-dependent vascular dysfunction in mouse models of diabetes.


2021 ◽  
Vol 21 ◽  
Author(s):  
Zhen Zhao ◽  
Yu Lu ◽  
Huan Wang ◽  
Xiang Gu ◽  
Luting Zhu ◽  
...  

Background: Some studies demonstrated that under high-glucose (HG) condition, osteoblasts develop oxidative stress, which will impair their normal functions. The effects of activin receptor-like kinase 7 (ALK7) silencing on HG-induced osteoblasts remained unclear. Objective: The aim of this study was to explore the effect of ALK7 on HG-induced osteoblasts. Methods: MC3T3-E1 cells were treated with different concentrations of HG (0, 50, 100, 200 and 300mg/dL), and the cell viability was detected using cell counting kit-8 (CCK-8). HG-treated MC3T3-E1 cells were transfected with siALK7 or ALK7 overexpression plasmid or siNrf2, and then the viability and apoptosis were detected by CCK-8 and flow cytometry. The levels of reactive oxygen species (ROS), collagen I and calcification nodule were determined by oxidative stress kits, Enzyme-linked immunosorbent assay and Alizarin red staining. The expressions of NF-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and osteoblast-associated genes were determined by quantitative real-time PCR (qRT-PCR) and Western blot. Results: Cell viability was reduced with HG treatment. Silencing ALK7 inhibited the effect of HG on increasing cell apoptosis and ROS production, reduced cell viability, mineralized nodules, and downregulated collagen I and osteoblast-associated genes expression in MC3T3-E1 cells. ALK7 silencing activated the Nrf2/HO-1 signaling pathway by affecting expressions of HO-1 and Nrf2. ALK7 overexpression had the opposite effects. In addition, siNrf2 partially reversed the effects of ALK7 silencing on HG-induced MC3T3-E1 cells. Conclusion: ALK7 silencing protected osteoblasts under HG condition possibly through activating the Nrf2/HO-1 pathway.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Kunxiao Zhao ◽  
Ying Li ◽  
Ziqiang Wang ◽  
Ning Han ◽  
Ying Wang

Diabetic nephropathy is the complication of diabetes mellitus that can lead to chronic renal failure. Reactive oxygen species (ROS) production plays an important role in its pathological process. Previous studies showed that carnosine may reduce diabetic nephropathy by antioxidant effect. However, the molecular mechanism of its antioxidant was not fully understood. In the current study, we developed high glucose containing different concentrations of carnosine to reduce ROS levels and podocytes apoptosis, and Cell Counting Kit-8 test was used to observe the cell viability. Carnosine (5-20mM) was found to protect mouse podocytes (MPC5) cells from HG-induced injury. Quantitative real-time PCR, Western blotting, and immunofluorescence staining revealed that high glucose induced ROS levels and podocytes apoptosis were downregulated by PI3K/AKT and Nrf2 signaling pathways. The current findings suggest that carnosine may reduce ROS levels and MPC5 cells apoptosis by PI3K/AKT and Nrf2 signaling pathways activation.


2020 ◽  
Vol 21 (7) ◽  
pp. 2324
Author(s):  
Shou Oosuka ◽  
Teruyo Kida ◽  
Hidehiro Oku ◽  
Taeko Horie ◽  
Seita Morishita ◽  
...  

Purpose: To investigate the effect of a selective aquaporin 4 (AQP4) inhibitor, 2-(nicotinamide)-1,3,4-thiadiazole (TGN-020), on the expression of vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) production, as well as on the retinal edema in diabetic retina. Methods: Intravitreal injections of bevacizumab, TGN-020, or phosphate-buffered saline (PBS) were performed on streptozotocin-induced diabetic rats. Retinal sections were immunostained for anti-glial fibrillary acidic protein (GFAP), anti-AQP4, and anti-VEGF. Protein levels of VEGF from collected retinas were determined by Western blot analysis. In addition, retinal vascular leakage of Evans Blue was observed in the flat-mounted retina from the diabetic rats in the presence or absence of TGN-020. Volumetric changes of rat retinal Müller cells (TR-MUL5; transgenic rat Müller cells) and intracellular levels of ROS were determined using flow cytometry analysis of ethidium fluorescence in the presence or absence of TGN-020 or bevacizumab under physiological and high glucose conditions. Results: In the diabetic retina, the immunoreactivity and protein levels of VEGF were suppressed by TGN-020. AQP4 immunoreactivity was higher than in the control retinas and the expressions of AQP4 were co-localized with GFAP. Similarly to VEGF, AQP4 and GFAP were also suppressed by TGN-020. In the Evans Blue assay, TGN-020 decreased leakage in the diabetic retinas. In the cultured Müller cells, the increase in cell volumes and intracellular ROS production under high glucose condition were suppressed by exposure to TGN-020 as much as by exposure to bevacizumab. Conclusion: TGN-020 may have an inhibitory effect on diabetic retinal edema.


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