Alperujo, an antioxidant-rich by-product of olive oil extraction, could protect β-cells against oxidative damage. Our goal was to study the antioxidant effects of an alperujo extract (AE) on MIN6 β-cells challenged ...Alperujo, an antioxidant-rich by-product of olive oil extraction, could protect β-cells against oxidative damage. Our goal was to study the antioxidant effects of an alperujo extract (AE) on MIN6 β-cells challenged with glucose or hydrogen peroxide. MIN6 β-cells were challenged with glucose (100 mM) or H2O2 (0.15 mM), with or without AE (20 μM phenol). Reactive oxygen species, intracellular iron (Fe), insulin, glucose uptake, and mRNA gene expression of Uncoupling Protein-2 (UCP-2), Thioredoxin (TRDX), p47phox, and the ratio Bax/Bcl-2 were measured. ROS increased when the stressors were incubated with AE (p < 0.05 and p < 0.01, respectively). Intracellular Fe increased in glucose presence (100 mM p < 0.001). Insulin secretion improved when cells were pre-incubated with AE (p < 0.001) and glucose uptake increased when cells were pre-incubated with AE for 3 days and then further treated with glucose (p < 0.001). After 3 days of AE alone, mRNA relative expression of UCP-2 and TRDX increased (p < 0.001) and after 5 days p47phox, also increased. The Bax/Bcl-2 ratio tended to decrease in the samples pre-incubated with AE. The Alperujo extract,in vitro, had a pro-oxidant behavior, however pre-incubating MIN6 β-cells with AE tended to protect them against apoptosis, thereby enhancing insulin secretion.展开更多
AIM:To evaluate the effects of LIN28A(human)on high glucose-induced retinal pigmented epithelium(RPE)cell injury and its possible mechanism.METHODS:Diabetic retinopathy model was generated following 48h of exposure to...AIM:To evaluate the effects of LIN28A(human)on high glucose-induced retinal pigmented epithelium(RPE)cell injury and its possible mechanism.METHODS:Diabetic retinopathy model was generated following 48h of exposure to 30 mmol/L high glucose(HG)in ARPE-19 cells.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blot tested the expression of the corresponding genes and proteins.Cell viability as well as apoptosis was determined through cell counting kit-8(CCK-8)and flow cytometry assays.Immunofluorescence assay was adopted to evaluate autophagy activity.Caspase 3 activity,oxidative stress markers,and cytokines were appraised adopting their commercial kits,respectively.Finally,ARPE-19 cells were preincubated with EX527,a Sirtuin 1(SIRT1)inhibitor,prior to HG stimulation to validate the regulatory mechanism.RESULTS:LIN28A was downregulated in HG-challenged ARPE-19 cells.LIN28A overexpression greatly inhibited HGinduced ARPE-19 cell viability loss,apoptosis,oxidative damage as well as inflammatory response.Meanwhile,the repressed autophagy and SIRT1 in ARPE-19 cells challenged with HG were elevated after LIN28A overexpression.In addition,treatment of EX527 greatly inhibited the activated autophagy following LIN28A overexpression and partly abolished the protective role of LIN28A against HG-elicited apoptosis,oxidative damage as well as inflammation in ARPE-19 cells.CONCLUSION:LIN28A exerts a protective role against HG-elicited RPE oxidative damage,inflammation,as well as apoptosis via regulating SIRT1/autophagy.展开更多
Objective To explore the protective effects of dexmedetomidine(Dex)against high glucose-induced epithelial-mesenchymal transition in HK-2 cells and relevant mechanisms.Methods HK-2 cells were exposed to either glucose...Objective To explore the protective effects of dexmedetomidine(Dex)against high glucose-induced epithelial-mesenchymal transition in HK-2 cells and relevant mechanisms.Methods HK-2 cells were exposed to either glucose or glucose+Dex for 6 h.The production of ROS,morphology of HK-2 cells,and cell cycle were detected.Moreover,the expression of AKT,p-AKT,ERK,pERK,PI3 K,E-Cadherin,Claudin-1,andα-SMA were determined and compared between HK-2 cells exposed to glucose and those exposed to both glucose and Dex with or without PI3 K/AKT pathway inhibitor LY294002 and ERK pathway inhibitor U0126.Results Compared with HK-2 cells exposed to high level of glucose,the HK-2 cells exposed to both high level of glucose and Dex showed:(1)lower level of ROS production;(2)cell morphology was complete;(3)more cells in G1 phase;(4)lower expression of p-AKT,p-ERK andα-SMA,higher expression of ECadherin and Claudin-1.PI3 K/AKT inhibitor LY294002 and ERK inhibitor U0126 decreased the expression of p-AKT,p-ERK andα-SMA,and increased the expression of E-Cadherin and Claudin-1.Conclusion Dex can attenuate high glucose-induced HK-2 epithelial-mesenchymal transition by inhibiting AKT and ERK.展开更多
Iron overload can lead to cytotoxicity, and it is a risk factor for diabetic peripheral neuropathy. However, the underlying mechanism remains unclear. We conjectured that iron overload-induced neurotoxicity might be a...Iron overload can lead to cytotoxicity, and it is a risk factor for diabetic peripheral neuropathy. However, the underlying mechanism remains unclear. We conjectured that iron overload-induced neurotoxicity might be associated with oxidative stress and the NF-E2-related factor 2 （Nrf2）/ARE signaling pathway. As an in vitro cellular model of diabetic peripheral neuropathy, PC12 cells ex- posed to high glucose concentration were used in this study. PC12 cells were cultured with ferric ammonium citrate at different concentrations to create iron overload. PC12 cells cultured in ferric ammonium citrate under high glucose concentration had significantly low cell viability, a high rate of apoptosis, and elevated reactive oxygen species and malondialdehyde levels. These changes were dependent on ferric ammonium citrate concentration. Nrf2 mRNA and protein expression in the ferric ammonium citrate groups were inhibited markedly in a dose-dependent manner. All changes could be inhibited by addition of deferoxamine. These results indicate that iron overload aggravates oxidative stress injury in neural cells under high glucose concentration and that the Nrf2/ARE sigfnaling pathway might play an important role in this process.展开更多
Objective: To study the protective effect and molecular mechanism of glucagon-like peptide-1 (GLP-1) on the high glucose-induced endothelial cell injury. Methods: Endothelial cells HUVECs were cultured and divided int...Objective: To study the protective effect and molecular mechanism of glucagon-like peptide-1 (GLP-1) on the high glucose-induced endothelial cell injury. Methods: Endothelial cells HUVECs were cultured and divided into three groups, control group were treated with serum-free low-glucose culture medium, high glucose group were treated with serum-free culture medium containing 40 mmol/L glucose and GLP-1 group were treated with serum-free culture medium containing 10 mmol/L GLP-1 and 40 mmol/L glucose. 24 h after treatment, the expression of apoptosis genes and autophagy genes as well as the levels of oxidative stress products and antioxidants were measured. Results: JAK2, STAT3, Bax, Caspase-9, Caspase-3, Nrf2, NQO1, HO1 and GSH-Px mRNA expression as well as ROS, gp91phox, MDA and ox-LDL levels in high glucose group of cells were significantly higher than those in control group while STSQM1, Atg-5 and LC-3 mRNA expression were significantly lower than those of control group;JAK2, STAT3, Bax, Caspase-9 and Caspase-3 mRNA expression as well as ROS, gp91phox, MDA and ox-LDL levels in GLP-1 group of cells were significantly lower than those in high glucose group while Nrf2, NQO1, HO1, GSH-Px, STSQM1, Atg-5 and LC-3mRNA expression were significantly higher than those in high glucose group. Conclusion:GLP-1 can reduce the high glucose-induced endothelial cell injury by inhibiting apoptosis, reducing oxidative stress and enhancing autophagy.展开更多
Background Diabetic cardiomyopathy is the major cause of morbidity and mortality in diabetic patients. Oxidative stress plays an important role in diabetic cardiomyopathy. This study aimed to investigate the effects o...Background Diabetic cardiomyopathy is the major cause of morbidity and mortality in diabetic patients. Oxidative stress plays an important role in diabetic cardiomyopathy. This study aimed to investigate the effects of adiponectin on oxidative stress and apoptosis in human cardiac myocytes （HCM） cultured with high glucose. Methods The cells were assigned to three group： control group, high glucose group and high glucose plus adiponectin group. After culture for 24, 48, 72 hours, oxidative stress was evaluated by detecting levels of malondialdehyde （MDA） and superoxide dismutase （SOD） in the supernatant of culture media. The expression of p66Shc and Heme oxygenase-1 （HO-1） was detected by real-time polymerase chain reaction （PCR）. Flow cytometry was designed to observe and detect cellular apoptosis. Results Our findings showed significant increase in MDA levels and decrease in SOD activity in the high glucose group compared with the control group （P 〈0.05）. However, MDA levels were significantly decreased and SOD activity was significantly increased in the adiponectin group compared with those in the high-glucose group （P 〈0.05）. The mRNA expression of HO-1 in the high glucose group was significantly increased in a time-dependent manner compared with that in the control group （P 〈0.05）. Adiponectin further increased the mRNA expression of HO-1 induced by high glucose in a time-dependent manner （P 〈0.05）.The expression of p66Shc was significantly increased in high glucose group compared with that in the control group （P 〈0.05）. Adiponectin significantly suppressed the upregulation of p66Shc induced by high glucose （P 〈0.05）. The apoptotic rate of cardiomyocytes was significantly increased in the high glucose group compared with that in the control group while the apoptotic rate in the adiponectin group was remarkably declined in comparison with that in the high glucose group. Conclusion Adiponectin reduces high glucose-induced oxidative stress and apoptosis and plays a protective role in myocardial cells by upregulating the HO-1 expression and downregulating p66Shc expression.展开更多
AIM:To investigate the effect of novel probiotics on the clinical characteristics of high-fructose induced metabolic syndrome.METHODS:Male Wistar rats aged 4 wk were fed a 70% w/w high-fructose diet(n = 27) or chow di...AIM:To investigate the effect of novel probiotics on the clinical characteristics of high-fructose induced metabolic syndrome.METHODS:Male Wistar rats aged 4 wk were fed a 70% w/w high-fructose diet(n = 27) or chow diet(n = 9) for 3 wk to induce metabolic syndrome,the rats were then randomized into groups and administered probiotic [Lactobacillus curvatus(L.curvatus) HY7601 and Lactobacillus plantarum(L.plantarum) KY1032] at 109 cfu/d or 1010 cfu/d or placebo by oral gavage for 3 wk.Food intake and body weight were measured once a week.After 6 wk,the rats were fasted for 12 h,then anesthetized with diethyl ether and sacrificed.Blood samples were taken from the inferior vena cava for plasma analysis of glucose,insulin,C-peptide,totalcholesterol,triglycerides and thiobarbituric acid-reacting substances.Real-time polymerase chain reaction was performed using mouse-specific Taqman probe sets to assess genes related to fatty acid β-oxidation,lipogenesis and cholesterol metabolism in the liver.Target gene expression was normalized to the housekeeping gene,glyceraldehyde-3-phosphate dehydrogenase.RESULTS:Rodents fed a high-fructose diet developed clinical characteristics of the metabolic syndrome including increased plasma glucose,insulin,triglycerides,total cholesterol and oxidative stress levels,as well as increased liver mass and liver lipids compared to chow fed controls.Probiotic treatment(L.curvatus HY7601 and L.plantarum KY1032) at high(1010 cfu/d) or low dosage(109 cfu/d) lowered plasma glucose,insulin,triglycerides and oxidative stress levels.Only high-dose probiotic treatment reduced liver mass and liver cholesterol.Probiotic treatment reduced lipogenesis via downregulation of SREBP1,FAS and SCD1 mRNA levels and increased β-oxidation via up-regulation of PPARα and CPT2 mRNA levels.CONCLUSION:Probiotic L.curvatus HY7601 and L.plantarum KY1032 combined suppressed the clinical characteristics of high-fructose-induced metabolic syndrome,therefore,may provide a natural alternative for the treatment of diet-induced metabolic syndrome.展开更多
文摘Alperujo, an antioxidant-rich by-product of olive oil extraction, could protect β-cells against oxidative damage. Our goal was to study the antioxidant effects of an alperujo extract (AE) on MIN6 β-cells challenged with glucose or hydrogen peroxide. MIN6 β-cells were challenged with glucose (100 mM) or H2O2 (0.15 mM), with or without AE (20 μM phenol). Reactive oxygen species, intracellular iron (Fe), insulin, glucose uptake, and mRNA gene expression of Uncoupling Protein-2 (UCP-2), Thioredoxin (TRDX), p47phox, and the ratio Bax/Bcl-2 were measured. ROS increased when the stressors were incubated with AE (p < 0.05 and p < 0.01, respectively). Intracellular Fe increased in glucose presence (100 mM p < 0.001). Insulin secretion improved when cells were pre-incubated with AE (p < 0.001) and glucose uptake increased when cells were pre-incubated with AE for 3 days and then further treated with glucose (p < 0.001). After 3 days of AE alone, mRNA relative expression of UCP-2 and TRDX increased (p < 0.001) and after 5 days p47phox, also increased. The Bax/Bcl-2 ratio tended to decrease in the samples pre-incubated with AE. The Alperujo extract,in vitro, had a pro-oxidant behavior, however pre-incubating MIN6 β-cells with AE tended to protect them against apoptosis, thereby enhancing insulin secretion.
基金Supported by Medical and Health Science and Technology Project of Zhejiang Province(No.2023KY1356).
文摘AIM:To evaluate the effects of LIN28A(human)on high glucose-induced retinal pigmented epithelium(RPE)cell injury and its possible mechanism.METHODS:Diabetic retinopathy model was generated following 48h of exposure to 30 mmol/L high glucose(HG)in ARPE-19 cells.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blot tested the expression of the corresponding genes and proteins.Cell viability as well as apoptosis was determined through cell counting kit-8(CCK-8)and flow cytometry assays.Immunofluorescence assay was adopted to evaluate autophagy activity.Caspase 3 activity,oxidative stress markers,and cytokines were appraised adopting their commercial kits,respectively.Finally,ARPE-19 cells were preincubated with EX527,a Sirtuin 1(SIRT1)inhibitor,prior to HG stimulation to validate the regulatory mechanism.RESULTS:LIN28A was downregulated in HG-challenged ARPE-19 cells.LIN28A overexpression greatly inhibited HGinduced ARPE-19 cell viability loss,apoptosis,oxidative damage as well as inflammatory response.Meanwhile,the repressed autophagy and SIRT1 in ARPE-19 cells challenged with HG were elevated after LIN28A overexpression.In addition,treatment of EX527 greatly inhibited the activated autophagy following LIN28A overexpression and partly abolished the protective role of LIN28A against HG-elicited apoptosis,oxidative damage as well as inflammation in ARPE-19 cells.CONCLUSION:LIN28A exerts a protective role against HG-elicited RPE oxidative damage,inflammation,as well as apoptosis via regulating SIRT1/autophagy.
文摘Objective To explore the protective effects of dexmedetomidine(Dex)against high glucose-induced epithelial-mesenchymal transition in HK-2 cells and relevant mechanisms.Methods HK-2 cells were exposed to either glucose or glucose+Dex for 6 h.The production of ROS,morphology of HK-2 cells,and cell cycle were detected.Moreover,the expression of AKT,p-AKT,ERK,pERK,PI3 K,E-Cadherin,Claudin-1,andα-SMA were determined and compared between HK-2 cells exposed to glucose and those exposed to both glucose and Dex with or without PI3 K/AKT pathway inhibitor LY294002 and ERK pathway inhibitor U0126.Results Compared with HK-2 cells exposed to high level of glucose,the HK-2 cells exposed to both high level of glucose and Dex showed:(1)lower level of ROS production;(2)cell morphology was complete;(3)more cells in G1 phase;(4)lower expression of p-AKT,p-ERK andα-SMA,higher expression of ECadherin and Claudin-1.PI3 K/AKT inhibitor LY294002 and ERK inhibitor U0126 decreased the expression of p-AKT,p-ERK andα-SMA,and increased the expression of E-Cadherin and Claudin-1.Conclusion Dex can attenuate high glucose-induced HK-2 epithelial-mesenchymal transition by inhibiting AKT and ERK.
基金supported by the Natural Science Foundation of Hubei Province,No.2010CDB09001
文摘Iron overload can lead to cytotoxicity, and it is a risk factor for diabetic peripheral neuropathy. However, the underlying mechanism remains unclear. We conjectured that iron overload-induced neurotoxicity might be associated with oxidative stress and the NF-E2-related factor 2 （Nrf2）/ARE signaling pathway. As an in vitro cellular model of diabetic peripheral neuropathy, PC12 cells ex- posed to high glucose concentration were used in this study. PC12 cells were cultured with ferric ammonium citrate at different concentrations to create iron overload. PC12 cells cultured in ferric ammonium citrate under high glucose concentration had significantly low cell viability, a high rate of apoptosis, and elevated reactive oxygen species and malondialdehyde levels. These changes were dependent on ferric ammonium citrate concentration. Nrf2 mRNA and protein expression in the ferric ammonium citrate groups were inhibited markedly in a dose-dependent manner. All changes could be inhibited by addition of deferoxamine. These results indicate that iron overload aggravates oxidative stress injury in neural cells under high glucose concentration and that the Nrf2/ARE sigfnaling pathway might play an important role in this process.
基金Surface Project of National Natural Science Foundation of China,No:81570440Shanghai Leading Talent Fund Project,No.:035.
文摘Objective: To study the protective effect and molecular mechanism of glucagon-like peptide-1 (GLP-1) on the high glucose-induced endothelial cell injury. Methods: Endothelial cells HUVECs were cultured and divided into three groups, control group were treated with serum-free low-glucose culture medium, high glucose group were treated with serum-free culture medium containing 40 mmol/L glucose and GLP-1 group were treated with serum-free culture medium containing 10 mmol/L GLP-1 and 40 mmol/L glucose. 24 h after treatment, the expression of apoptosis genes and autophagy genes as well as the levels of oxidative stress products and antioxidants were measured. Results: JAK2, STAT3, Bax, Caspase-9, Caspase-3, Nrf2, NQO1, HO1 and GSH-Px mRNA expression as well as ROS, gp91phox, MDA and ox-LDL levels in high glucose group of cells were significantly higher than those in control group while STSQM1, Atg-5 and LC-3 mRNA expression were significantly lower than those of control group;JAK2, STAT3, Bax, Caspase-9 and Caspase-3 mRNA expression as well as ROS, gp91phox, MDA and ox-LDL levels in GLP-1 group of cells were significantly lower than those in high glucose group while Nrf2, NQO1, HO1, GSH-Px, STSQM1, Atg-5 and LC-3mRNA expression were significantly higher than those in high glucose group. Conclusion:GLP-1 can reduce the high glucose-induced endothelial cell injury by inhibiting apoptosis, reducing oxidative stress and enhancing autophagy.
文摘Background Diabetic cardiomyopathy is the major cause of morbidity and mortality in diabetic patients. Oxidative stress plays an important role in diabetic cardiomyopathy. This study aimed to investigate the effects of adiponectin on oxidative stress and apoptosis in human cardiac myocytes （HCM） cultured with high glucose. Methods The cells were assigned to three group： control group, high glucose group and high glucose plus adiponectin group. After culture for 24, 48, 72 hours, oxidative stress was evaluated by detecting levels of malondialdehyde （MDA） and superoxide dismutase （SOD） in the supernatant of culture media. The expression of p66Shc and Heme oxygenase-1 （HO-1） was detected by real-time polymerase chain reaction （PCR）. Flow cytometry was designed to observe and detect cellular apoptosis. Results Our findings showed significant increase in MDA levels and decrease in SOD activity in the high glucose group compared with the control group （P 〈0.05）. However, MDA levels were significantly decreased and SOD activity was significantly increased in the adiponectin group compared with those in the high-glucose group （P 〈0.05）. The mRNA expression of HO-1 in the high glucose group was significantly increased in a time-dependent manner compared with that in the control group （P 〈0.05）. Adiponectin further increased the mRNA expression of HO-1 induced by high glucose in a time-dependent manner （P 〈0.05）.The expression of p66Shc was significantly increased in high glucose group compared with that in the control group （P 〈0.05）. Adiponectin significantly suppressed the upregulation of p66Shc induced by high glucose （P 〈0.05）. The apoptotic rate of cardiomyocytes was significantly increased in the high glucose group compared with that in the control group while the apoptotic rate in the adiponectin group was remarkably declined in comparison with that in the high glucose group. Conclusion Adiponectin reduces high glucose-induced oxidative stress and apoptosis and plays a protective role in myocardial cells by upregulating the HO-1 expression and downregulating p66Shc expression.
基金Supported by The Basic Science Research Program,Center for Food and Nutritional Genomicsthe National Research Foundation(NRF) of Korea funded by the Ministry of Education,Science and Technology,No.2011-0000912Korea Yakult Co., Ltd.
文摘AIM:To investigate the effect of novel probiotics on the clinical characteristics of high-fructose induced metabolic syndrome.METHODS:Male Wistar rats aged 4 wk were fed a 70% w/w high-fructose diet(n = 27) or chow diet(n = 9) for 3 wk to induce metabolic syndrome,the rats were then randomized into groups and administered probiotic [Lactobacillus curvatus(L.curvatus) HY7601 and Lactobacillus plantarum(L.plantarum) KY1032] at 109 cfu/d or 1010 cfu/d or placebo by oral gavage for 3 wk.Food intake and body weight were measured once a week.After 6 wk,the rats were fasted for 12 h,then anesthetized with diethyl ether and sacrificed.Blood samples were taken from the inferior vena cava for plasma analysis of glucose,insulin,C-peptide,totalcholesterol,triglycerides and thiobarbituric acid-reacting substances.Real-time polymerase chain reaction was performed using mouse-specific Taqman probe sets to assess genes related to fatty acid β-oxidation,lipogenesis and cholesterol metabolism in the liver.Target gene expression was normalized to the housekeeping gene,glyceraldehyde-3-phosphate dehydrogenase.RESULTS:Rodents fed a high-fructose diet developed clinical characteristics of the metabolic syndrome including increased plasma glucose,insulin,triglycerides,total cholesterol and oxidative stress levels,as well as increased liver mass and liver lipids compared to chow fed controls.Probiotic treatment(L.curvatus HY7601 and L.plantarum KY1032) at high(1010 cfu/d) or low dosage(109 cfu/d) lowered plasma glucose,insulin,triglycerides and oxidative stress levels.Only high-dose probiotic treatment reduced liver mass and liver cholesterol.Probiotic treatment reduced lipogenesis via downregulation of SREBP1,FAS and SCD1 mRNA levels and increased β-oxidation via up-regulation of PPARα and CPT2 mRNA levels.CONCLUSION:Probiotic L.curvatus HY7601 and L.plantarum KY1032 combined suppressed the clinical characteristics of high-fructose-induced metabolic syndrome,therefore,may provide a natural alternative for the treatment of diet-induced metabolic syndrome.
