AIM: To investigate the signaling mechanism of antioxidative action by curcumin and its impact on glucose disposal. METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n =...AIM: To investigate the signaling mechanism of antioxidative action by curcumin and its impact on glucose disposal. METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n = 20) to induce obesity and insulin resistance. After 16 wk, 10 HFD-fed mice were further treated with daily curcumin oral gavage at the dose of 50 mg/kg body weight (BW) (HFD + curcumin group). After 15 d of the curcumin supplementation, an intraperitoneal glucose tolerance test was performed. Fasting blood samples were also collected for insulin and glucose measurements. Insulin-sensitive tissues, including muscle, adipose tissue and the liver, were isolated for the assessments of malondialdehyde (MDA), reactive oxygen species (ROS)and nuclear factor erythroid-2-related factor-2 (Nrf2) signaling. RESULTS: We show here that in a HFD mouse model, short-term curcumin gavage attenuated glucose intolerance without affecting HFD-induced BW gain. Curcumin also attenuated HFD-induced elevations of MDA and ROS in the skeletal muscle, particularly in its mitochondrial fraction, but it had no such an effect in either adipose tissue or the liver of HFD-fed mice. Correspondingly, in skeletal muscle, the levels of total or nuclear content of Nrf2, as well as its downstream target, heme oxygenase-1, were reduced by HFD-feeding. Curcumin intervention dramatically reversed these defects in Nrf2 signaling. Further analysis of the relationship of oxidative stress with glucose level by a regression analysis showed a positive and significant correlation between the area under the curve of a glucose tolerance test with MDA levels either in muscle or muscular mitochondria. CONCLUSION: These findings suggest that the shortterm treatment of curcumin in HFD-fed mice effectively ameliorates muscular oxidative stress by activating Nrf2 function that is a novel mechanism for its effect in improving glucose intolerance.展开更多
Chalcone is a plant metabolite widely found in fruits,vegetables,spices and tea,and has anti-tumor,anti-inflammation,immunomodulation,antibacterial and anti-oxidation activities,as well as many other pharmacological a...Chalcone is a plant metabolite widely found in fruits,vegetables,spices and tea,and has anti-tumor,anti-inflammation,immunomodulation,antibacterial and anti-oxidation activities,as well as many other pharmacological and biological effects.Our team has shown that its analogs have antioxidant activity,and oxidative stress is a pathological hallmark of retinal ischemia/reperfusion injury that can lead to retinal damage and visual loss.This investigation aims to identify a chalcone that protects retinal ganglion cells in vitro from the effects of oxidative stress and examine its mechanism.Rat retinal ganglion cell-5 cells were pretreated with chalcones and then exposed to tert-butyl hydroperoxide that causes oxidative damage.Controls received dimethyl sulfoxide only or tert-butyl hydroperoxide in dimethyl sulfoxide.Only（E）-3,4-dihydroxy-2′-methylether ketone（L2 H17）,of the five chalcone analogs,markedly increased the survival rate of oxidatively injured RGC-5 cells.Thus,subsequent experiments only analyzed the results of the L2 H17 intervention.Cell viability and apoptosis were measured.Intracellular superoxide dismutase and reactive oxygen species levels were used to assess induced oxidative stress.The mechanism of action by L2 H17 was explored by measuring the ER stress/UPR pathway and the expression and localization of Nrf2.All results demonstrated that L2 H17 could reduce the apoptosis of oxidatively injured cells,inhibit caspase-3 activity,increase Bcl-2 expression,decrease Bad expression,increase the activity of superoxide dismutase,inhibit the production of reactive oxygen species,increase Nrf2 immunoreactivity,and reduce the activating transcription factor 4,phospho-eukaryotic initiation factor 2 and CHOP expression.L2 H17 protects retinal ganglion cells induced by oxidative stress by regulating Nrf2,which indicates that it has the potential to become a drug for retinal ischemia/reperfusion.展开更多
OBJECTIVE To investigate the neuroprotective effects of quercetin on central neurons against chronic high glucose in central neurons,in relation to Nrf2/ARE/Glo-1 activation.METHODS SH-SY5Y cells were cultured with hi...OBJECTIVE To investigate the neuroprotective effects of quercetin on central neurons against chronic high glucose in central neurons,in relation to Nrf2/ARE/Glo-1 activation.METHODS SH-SY5Y cells were cultured with high glucose(HG,70 mmol·L^(-1)),4-fold of the normal glucose(17.5 mmol·L^(-1)).Quercetin was set three concentrations(5,10,20μmol·L^(-1)),with Nrf2 activator sulforaphane(SFN)as a positive group(2.5μmol·L^(-1)).After 72 h,cells were collected for glyoxalase 1(Glo-1)activity and GSH level were by spectrophotometry;advanced glycation end-products(AGEs)as well as nuclear Nrf2 and p-Nrf2 levels by immunofluorescence;Glo-1,γ-glutamycysteine synthase(γ-GCS),Nrf2 and p-Nrf2 protein levels by Western blotting,and Glo-1 andγ-GCS m RNA levels by real-time qP CR.RESULTS Quercetin increased the cell viability of SH-SY5Y cells,and upregulated the levels of Glo-1 activity,protein,and m RNA in SH-SY5Y cells cultured with HG,accompanied by the elevated levels of glutathione,a cofactor of Glo-1 activity,and the reduced levels of AGEs.Meanwhile,quercetin could increase p-Nrf2 and Nrf2 levels in nucleus as well as p-Nrf2 levels in cytosol of SH-SY5Y cells exposed to chronic HG,accompanied by the elevated protein expression and m RNA levels ofγ-GCS,a known target gene of Nrf2/ARE signaling.Moreover,a PKC activator or a p38MAPK inhibitor pretreatment could significantly increase the protein expression ofγ-GCS in HG condition,but an alkylating agent for sulfydryl of cysteine in Keap 1,a negative regulator of Nrf2,pretreatment only showed an increased tendency ofγ-GCS protein,compared with without pretreatment;however,after pretreatment with those tool drugs,co-treatment with quercetin and HG had similar results to those of single tool drug pretreatment followed by HG exposure.CONCLUSION Firstly,quercetin can enhance Glo-1 function in central neurons,which is mediated by activation of Nrf2/ARE pathway,then exerts the neuroprotection against HG induced damage;moreover,PKC and p38 MAPK pathways may be involved in Nrf2 inactivation in chronic HG condition.展开更多
OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmo...OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmonary disease(COPD),which was a serious disease of respiratory system.METHODS We duplicate the emphysema model with porcine pancreatic elastase(PPE)in Nrf2-/-and WT mouse for 21d,and intraperitoneal injection of Li Cl,the activator of Wnt/β-catenin signaling pathway from 14 d to the end.Hematoxylin and eosin(H&E)staining was performed to assess the histopathologic level,and immunohistochemistry(IHC)for Mac-3(the marker of macrophagocyte)and Ly6G(the marker of neutrophil)was used to observe the inflammatory infiltrate,while the levels of Wnt/β-catenin and Nrf2 signaling pathways related proteins heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),and the expression of inflammatory cytokine interleukin-6(IL-6)were detected by Western blotting of lung tissues.In vitro,cigarette smoke extract(CSE)-treated normal human bronchial epithelial(NHBE)cells,cell viability was examined by MTT assay,and then we treated recombinant human Wnt3a,si Nrf2 and si Wnt3a to measure the expression of Wnt3a,β-catenin,Nrf2,HO-1,NQO-1,and IL-6.Cellular immunofluorescence staining was employed to identify the nuclear translocation of Nrf2.RESULTS We found that the Li Cl-treated group has markedly decreased the damage of alveolar structure and inflammatory signs than the model group of WT mice rather than Nrf2-/-group.It also seen that Li Cl not only increasedβ-catenin,but it also led to a comparable increase in Nrf2,HO-1,NQO1,and decrease of IL-6 compared with WT model groups but except to Nrf2-/-group in vivo.And it showed that Wnt3atreatment has significantly increased the nuclear translocation of Nrf2 and the expression of HO-1 and NQO1,reduced the IL-6 release,while there has no significance when Nrf2 was blocked in CSE-induced NHBE cells.CONCLUSION Our results demonstrated that Wnt3a/β-catenin significantly balanced oxidative stress and attenuated inflammation reaction by promoting Nrf2 nuclear translocation and activity.展开更多
Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascula...Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascular endothelial growth factor therapies against neovascular age-related macular degeneration;however, effective treatment is not yet available for geographical atrophy in dry agerelated macular degeneration or for preventing the progression from early or mid to the late stage of age-related macular degeneration. Both clinical and experimental investigations involving human agerelated macular degeneration retinas and animal models point towards the atrophic alterations in retinal pigment epithelium as a key feature in age-related macular degeneration progression. Retinal pigment epithelium cells are primarily responsible for cellular-structural maintenance and nutrition supply to keep photoreceptors healthy and functional. The retinal pigment epithelium constantly endures a highly oxidative environment that is balanced with a cascade of antioxidant enzyme systems regulated by nuclear factor erythroid-2-related factor 2 as a main redox sensing transcription factor. Aging and accumulated oxidative stress triggers retinal pigment epithelium dysfunction and eventually death. Exposure to both environmental and genetic factors aggravates oxidative stress damage in aging retinal pigment epithelium and accelerates retinal pigment epithelium degeneration in age-related macular degeneration pathophysiology. The present review summarizes the role of oxidative stress in retinal pigment epithelium degeneration, with potential impacts from both genetic and environmental factors in age-related macular degeneration development and progression. Potential strategies to counter retinal pigment epithelium damage and protect the retinal pigment epithelium through enhancing its antioxidant capacity are also discussed, focusing on existing antioxidant nutritional supplementation, and exploring nuclear factor erythroid-2-related factor 2 and its regulators including REV-ERBα as therapeutic targets to protect against age-related macular degeneration development and progression.展开更多
AIM: To evaluate the effect of an extract of Geranium schiedeanum(Gs) as a hepatoprotective agent against ethanol(Et OH)-induced toxicity in rats. METHODS: Male Wistar rats weighing 200-230 g were subjected to a 70% p...AIM: To evaluate the effect of an extract of Geranium schiedeanum(Gs) as a hepatoprotective agent against ethanol(Et OH)-induced toxicity in rats. METHODS: Male Wistar rats weighing 200-230 g were subjected to a 70% partial hepatectomy(PH); they were then divided into three groups(groups 1-3). During the experiment, animals in group 1 drank only water. The other two groups(2-3) drank an aqueous solution of Et OH(40%, v/v). Additionally, rats in group 3 received a Gs extract daily at a dose of 300 mg/kg body weight intragastically. Subsequently, to identify markers of liver damage in serum, alanine aminotransferase, aspartate aminotransferase, albumin and bilirubin were measured by colorimetric methods. Glucose, triglyceride and cholesterol concentrations were also determined. In addition, oxidative damage was estimated by measuring lipid peroxidation [using thiobarbituric-acid reactive substances(TBARS)] in both plasma and the liver and by measuring the total concentration of antioxidants in serum and the total antioxidant capacity in the liver. In addition, a liver mass gain assessment, total DNA analysis and a morpho-histological analysis of the liver from animals in all three groups were performed and compared. Finally, the number of deaths observed in the three groups was analyzed.RESULTS: Administration of the Geranium shiedeanum extract significantly reduced the unfavorable effect of ethanol on liver regeneration(restitution liver mass: PHEt OH group 60.68% vs PH-Gs-Et OH group 69.22%). This finding was congruent with the reduced levels of hepatic enzymes and the sustained or increased levels of albumin and decreased bilirubin in serum. The extract also modified the metabolic processes that regulate glucose and lipid levels, as observed from the serum measurements. Lower antioxidant levels and the liver damage induced by Et OH administration appeared to be mitigated by the extract, as observed from the TBARs(PH-Et OH group 200.14 mmol/mg vs PH-Gs-Et OH group 54.20 mmol/mg; P < 0.05), total status of antioxidants(PH-Et OH group 1.43 mmol/L vs PH-Gs-Et OH group 1.99 mmol/L; P < 0.05), total antioxidant capacity values, liver mass gain and total DNA determination(PH-Et OH group 4.80 mg/g vs PH-Gs-Et OH 9.10 mg/g; P < 0.05). Overall, these processes could be related to decreased mortality in these treated animals.CONCLUSION: The administered extract showed a hepatoprotective effect, limiting the Et OH-induced hepatotoxic effects. This effect can be related tomodulating oxido-reduction processes.展开更多
Objective： To investigate the effect of total flavone of haw leaves（TFHL） on the expression of nuclear factor erythroid-2 related factor（Nrf2） and other related factors in nonalcoholic steatohepatitis（NASH） rat...Objective： To investigate the effect of total flavone of haw leaves（TFHL） on the expression of nuclear factor erythroid-2 related factor（Nrf2） and other related factors in nonalcoholic steatohepatitis（NASH） rats induced by high-fat diet and then to further discuss the mechanism of TFHL＇s prevention against NASH. Methods： High-fat diet was fed to 40 rats to establish the NASH model. Then model rats were intragastrically administrated with 40, 80, 160 mg/（kg·day） TFHL, respectively. The pathological changes of liver tissues in NASH rats were detected by oil red O and hematoxylin-eosin（HE） stainings. The expression of Nrf2 in rat liver was examined through immunohistochemistry. The level of 8-iso-prostaglandin F2α in serum was detected through enzyme linked immunosorbent assay（ELISA）. The mR NA and protein levels of Nrf2 and other related factors in liver tissue were measured by real-time reverse transcriptionpolymerase chain reaction and western blot. Results： Lipid deposition, hepatic steatosis, focal necrosis in lobular inflammation and ballooning degeneration were emerged in livers of NASH rats. The 8-iso-prostaglandin F2α in the serum of NASH rats increased significantly compared with the control group（P〈0.05）. The mR NA of Nrf2, hemeoxyenase1（HO-1） and the mR NA and protein levels of quinine oxidoreductase（NQO1） in NASH rats liver tissue showed a striking increase, while the mR NA levels of Keap1, r-glutamylcysteine synthethase（rG CS） and glutathione S-transferase（GST） were significantly decreased compared with the control group（P〈0.05）. After TFHL treatment, 8-iso-prostaglandin F2α level in serum significantly decreased, and Nrf2 mR NA and protein levels in hepatocytes nucleus enhanced compared with the model group（P〈0.05 or 0.01）. Meanwhile the Keap1 mR NA, the mR NA and protein levels of HO-1, NQO1 antibody, rG CS antibody, GST increased after TFHL treatment（P〈0.05 or 0.01）. Conclusions： Nrf2 and other related factors were involved in development of NASH, and they also served as an important part in its occurrence. By regulating expression of Nrf2 and other related factors, TFHL may play a role in antioxidative stress and prevention of NASH.展开更多
Objective： To investigate the cytoprotective effects of Saeng-kankunbi-tang（生肝健脾汤, SKT）, a herbal prescription consisting of Artemisia capillaris and Alisma canaliculatum, and its underlying mechanism involved...Objective： To investigate the cytoprotective effects of Saeng-kankunbi-tang（生肝健脾汤, SKT）, a herbal prescription consisting of Artemisia capillaris and Alisma canaliculatum, and its underlying mechanism involved. Methods： In mice, blood biochemistry and histopathology were assessed in carbon tetrachloride（CCl4）-induced oxidative hepatic injury in vivo. The animal groups included vehicle-treated control, CCl4, SKT 500 mg/（kg·day） CCl4＋SKT 200 or 500 mg/（kg·day）. In Hep G2 cell, tert-butyl hydroperoxide（t BHP） induced severe oxidative stress and mitochondrial dysfunction in vitro. The cyto-protective effects of SKT were determined by 3-（4,5-dimethylthiazol）-2,5-diphenyltetrazolium bromide（MTT） assay, fluorescence activated cell sorting analysis and western blotting. Results： The administration of SKT prevented liver damage induced by CCl4 in mice, by inhibition of hepatocyte degeneration and inflammatory cell infiltration as well as plasma parameters such as alanine aminotransferase（P〈0.01）. Moreover, treatment with t BHP induced hepatocyte death and cellular reactive oxygen species production in hepatocyte cell line. However, SKT pretreatment（30–300 μg/m L） reduced this cell death and oxidative stress（P〈0.01）. More importantly, SKT inhibited the ability of t BHP to induce changes in mitochondrial membrane transition in cell stained with rhodamine 123（P〈0.01）. Furthermore, treatment with SKT induced extracellular signal-regulated kinases-mediated nuclear factor erythroid-2-related factor 2（Nrf2） activation as well as the expressions of heme oxygenase 1 and glutamate-cystein ligase catalytic, Nrf2 target genes. Conclusion： SKT has the ability to protect hepatocyte against oxidative stress and mitochondrial damage mediated by Nrf2 activation.展开更多
基金Supported by A National Natural Science Foundation of China Grant, No. 81072300 to Jin TR andYu ZW
文摘AIM: To investigate the signaling mechanism of antioxidative action by curcumin and its impact on glucose disposal. METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n = 20) to induce obesity and insulin resistance. After 16 wk, 10 HFD-fed mice were further treated with daily curcumin oral gavage at the dose of 50 mg/kg body weight (BW) (HFD + curcumin group). After 15 d of the curcumin supplementation, an intraperitoneal glucose tolerance test was performed. Fasting blood samples were also collected for insulin and glucose measurements. Insulin-sensitive tissues, including muscle, adipose tissue and the liver, were isolated for the assessments of malondialdehyde (MDA), reactive oxygen species (ROS)and nuclear factor erythroid-2-related factor-2 (Nrf2) signaling. RESULTS: We show here that in a HFD mouse model, short-term curcumin gavage attenuated glucose intolerance without affecting HFD-induced BW gain. Curcumin also attenuated HFD-induced elevations of MDA and ROS in the skeletal muscle, particularly in its mitochondrial fraction, but it had no such an effect in either adipose tissue or the liver of HFD-fed mice. Correspondingly, in skeletal muscle, the levels of total or nuclear content of Nrf2, as well as its downstream target, heme oxygenase-1, were reduced by HFD-feeding. Curcumin intervention dramatically reversed these defects in Nrf2 signaling. Further analysis of the relationship of oxidative stress with glucose level by a regression analysis showed a positive and significant correlation between the area under the curve of a glucose tolerance test with MDA levels either in muscle or muscular mitochondria. CONCLUSION: These findings suggest that the shortterm treatment of curcumin in HFD-fed mice effectively ameliorates muscular oxidative stress by activating Nrf2 function that is a novel mechanism for its effect in improving glucose intolerance.
基金supported by the National Natural Science Foundation of China,No.81473295(to ZMS),81373312(to XZ)and 81371028(to WCW)
文摘Chalcone is a plant metabolite widely found in fruits,vegetables,spices and tea,and has anti-tumor,anti-inflammation,immunomodulation,antibacterial and anti-oxidation activities,as well as many other pharmacological and biological effects.Our team has shown that its analogs have antioxidant activity,and oxidative stress is a pathological hallmark of retinal ischemia/reperfusion injury that can lead to retinal damage and visual loss.This investigation aims to identify a chalcone that protects retinal ganglion cells in vitro from the effects of oxidative stress and examine its mechanism.Rat retinal ganglion cell-5 cells were pretreated with chalcones and then exposed to tert-butyl hydroperoxide that causes oxidative damage.Controls received dimethyl sulfoxide only or tert-butyl hydroperoxide in dimethyl sulfoxide.Only（E）-3,4-dihydroxy-2′-methylether ketone（L2 H17）,of the five chalcone analogs,markedly increased the survival rate of oxidatively injured RGC-5 cells.Thus,subsequent experiments only analyzed the results of the L2 H17 intervention.Cell viability and apoptosis were measured.Intracellular superoxide dismutase and reactive oxygen species levels were used to assess induced oxidative stress.The mechanism of action by L2 H17 was explored by measuring the ER stress/UPR pathway and the expression and localization of Nrf2.All results demonstrated that L2 H17 could reduce the apoptosis of oxidatively injured cells,inhibit caspase-3 activity,increase Bcl-2 expression,decrease Bad expression,increase the activity of superoxide dismutase,inhibit the production of reactive oxygen species,increase Nrf2 immunoreactivity,and reduce the activating transcription factor 4,phospho-eukaryotic initiation factor 2 and CHOP expression.L2 H17 protects retinal ganglion cells induced by oxidative stress by regulating Nrf2,which indicates that it has the potential to become a drug for retinal ischemia/reperfusion.
基金supported by National Natural Science Foundation of China(81371210)Qing Lan Project of Jiangsu Province(2014)Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘OBJECTIVE To investigate the neuroprotective effects of quercetin on central neurons against chronic high glucose in central neurons,in relation to Nrf2/ARE/Glo-1 activation.METHODS SH-SY5Y cells were cultured with high glucose(HG,70 mmol·L^(-1)),4-fold of the normal glucose(17.5 mmol·L^(-1)).Quercetin was set three concentrations(5,10,20μmol·L^(-1)),with Nrf2 activator sulforaphane(SFN)as a positive group(2.5μmol·L^(-1)).After 72 h,cells were collected for glyoxalase 1(Glo-1)activity and GSH level were by spectrophotometry;advanced glycation end-products(AGEs)as well as nuclear Nrf2 and p-Nrf2 levels by immunofluorescence;Glo-1,γ-glutamycysteine synthase(γ-GCS),Nrf2 and p-Nrf2 protein levels by Western blotting,and Glo-1 andγ-GCS m RNA levels by real-time qP CR.RESULTS Quercetin increased the cell viability of SH-SY5Y cells,and upregulated the levels of Glo-1 activity,protein,and m RNA in SH-SY5Y cells cultured with HG,accompanied by the elevated levels of glutathione,a cofactor of Glo-1 activity,and the reduced levels of AGEs.Meanwhile,quercetin could increase p-Nrf2 and Nrf2 levels in nucleus as well as p-Nrf2 levels in cytosol of SH-SY5Y cells exposed to chronic HG,accompanied by the elevated protein expression and m RNA levels ofγ-GCS,a known target gene of Nrf2/ARE signaling.Moreover,a PKC activator or a p38MAPK inhibitor pretreatment could significantly increase the protein expression ofγ-GCS in HG condition,but an alkylating agent for sulfydryl of cysteine in Keap 1,a negative regulator of Nrf2,pretreatment only showed an increased tendency ofγ-GCS protein,compared with without pretreatment;however,after pretreatment with those tool drugs,co-treatment with quercetin and HG had similar results to those of single tool drug pretreatment followed by HG exposure.CONCLUSION Firstly,quercetin can enhance Glo-1 function in central neurons,which is mediated by activation of Nrf2/ARE pathway,then exerts the neuroprotection against HG induced damage;moreover,PKC and p38 MAPK pathways may be involved in Nrf2 inactivation in chronic HG condition.
基金The project supported by National Natural Science Foundation of China(81274172,81473267,30801535,81470003)
文摘OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmonary disease(COPD),which was a serious disease of respiratory system.METHODS We duplicate the emphysema model with porcine pancreatic elastase(PPE)in Nrf2-/-and WT mouse for 21d,and intraperitoneal injection of Li Cl,the activator of Wnt/β-catenin signaling pathway from 14 d to the end.Hematoxylin and eosin(H&E)staining was performed to assess the histopathologic level,and immunohistochemistry(IHC)for Mac-3(the marker of macrophagocyte)and Ly6G(the marker of neutrophil)was used to observe the inflammatory infiltrate,while the levels of Wnt/β-catenin and Nrf2 signaling pathways related proteins heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),and the expression of inflammatory cytokine interleukin-6(IL-6)were detected by Western blotting of lung tissues.In vitro,cigarette smoke extract(CSE)-treated normal human bronchial epithelial(NHBE)cells,cell viability was examined by MTT assay,and then we treated recombinant human Wnt3a,si Nrf2 and si Wnt3a to measure the expression of Wnt3a,β-catenin,Nrf2,HO-1,NQO-1,and IL-6.Cellular immunofluorescence staining was employed to identify the nuclear translocation of Nrf2.RESULTS We found that the Li Cl-treated group has markedly decreased the damage of alveolar structure and inflammatory signs than the model group of WT mice rather than Nrf2-/-group.It also seen that Li Cl not only increasedβ-catenin,but it also led to a comparable increase in Nrf2,HO-1,NQO1,and decrease of IL-6 compared with WT model groups but except to Nrf2-/-group in vivo.And it showed that Wnt3atreatment has significantly increased the nuclear translocation of Nrf2 and the expression of HO-1 and NQO1,reduced the IL-6 release,while there has no significance when Nrf2 was blocked in CSE-induced NHBE cells.CONCLUSION Our results demonstrated that Wnt3a/β-catenin significantly balanced oxidative stress and attenuated inflammation reaction by promoting Nrf2 nuclear translocation and activity.
基金supported by NIH/NEI R01 grants (EY031765,EY028100EY024963)+1 种基金BrightFocus Foundation,Research to Prevent Blindness Dolly Green Special Scholar AwardBoston Children’s Hospital Ophthalmology Foundation,Mass Lions Eye Research Fund Inc.(to JC)。
文摘Age-related macular degeneration is a primary cause of blindness in the older adult population. Past decades of research in the pathophysiology of the disease have resulted in breakthroughs in the form of anti-vascular endothelial growth factor therapies against neovascular age-related macular degeneration;however, effective treatment is not yet available for geographical atrophy in dry agerelated macular degeneration or for preventing the progression from early or mid to the late stage of age-related macular degeneration. Both clinical and experimental investigations involving human agerelated macular degeneration retinas and animal models point towards the atrophic alterations in retinal pigment epithelium as a key feature in age-related macular degeneration progression. Retinal pigment epithelium cells are primarily responsible for cellular-structural maintenance and nutrition supply to keep photoreceptors healthy and functional. The retinal pigment epithelium constantly endures a highly oxidative environment that is balanced with a cascade of antioxidant enzyme systems regulated by nuclear factor erythroid-2-related factor 2 as a main redox sensing transcription factor. Aging and accumulated oxidative stress triggers retinal pigment epithelium dysfunction and eventually death. Exposure to both environmental and genetic factors aggravates oxidative stress damage in aging retinal pigment epithelium and accelerates retinal pigment epithelium degeneration in age-related macular degeneration pathophysiology. The present review summarizes the role of oxidative stress in retinal pigment epithelium degeneration, with potential impacts from both genetic and environmental factors in age-related macular degeneration development and progression. Potential strategies to counter retinal pigment epithelium damage and protect the retinal pigment epithelium through enhancing its antioxidant capacity are also discussed, focusing on existing antioxidant nutritional supplementation, and exploring nuclear factor erythroid-2-related factor 2 and its regulators including REV-ERBα as therapeutic targets to protect against age-related macular degeneration development and progression.
基金Supported by SIP Project,No.20140856 and No.2014092,ESM-IPN
文摘AIM: To evaluate the effect of an extract of Geranium schiedeanum(Gs) as a hepatoprotective agent against ethanol(Et OH)-induced toxicity in rats. METHODS: Male Wistar rats weighing 200-230 g were subjected to a 70% partial hepatectomy(PH); they were then divided into three groups(groups 1-3). During the experiment, animals in group 1 drank only water. The other two groups(2-3) drank an aqueous solution of Et OH(40%, v/v). Additionally, rats in group 3 received a Gs extract daily at a dose of 300 mg/kg body weight intragastically. Subsequently, to identify markers of liver damage in serum, alanine aminotransferase, aspartate aminotransferase, albumin and bilirubin were measured by colorimetric methods. Glucose, triglyceride and cholesterol concentrations were also determined. In addition, oxidative damage was estimated by measuring lipid peroxidation [using thiobarbituric-acid reactive substances(TBARS)] in both plasma and the liver and by measuring the total concentration of antioxidants in serum and the total antioxidant capacity in the liver. In addition, a liver mass gain assessment, total DNA analysis and a morpho-histological analysis of the liver from animals in all three groups were performed and compared. Finally, the number of deaths observed in the three groups was analyzed.RESULTS: Administration of the Geranium shiedeanum extract significantly reduced the unfavorable effect of ethanol on liver regeneration(restitution liver mass: PHEt OH group 60.68% vs PH-Gs-Et OH group 69.22%). This finding was congruent with the reduced levels of hepatic enzymes and the sustained or increased levels of albumin and decreased bilirubin in serum. The extract also modified the metabolic processes that regulate glucose and lipid levels, as observed from the serum measurements. Lower antioxidant levels and the liver damage induced by Et OH administration appeared to be mitigated by the extract, as observed from the TBARs(PH-Et OH group 200.14 mmol/mg vs PH-Gs-Et OH group 54.20 mmol/mg; P < 0.05), total status of antioxidants(PH-Et OH group 1.43 mmol/L vs PH-Gs-Et OH group 1.99 mmol/L; P < 0.05), total antioxidant capacity values, liver mass gain and total DNA determination(PH-Et OH group 4.80 mg/g vs PH-Gs-Et OH 9.10 mg/g; P < 0.05). Overall, these processes could be related to decreased mortality in these treated animals.CONCLUSION: The administered extract showed a hepatoprotective effect, limiting the Et OH-induced hepatotoxic effects. This effect can be related tomodulating oxido-reduction processes.
基金Supported by the Zhejiang Provincial Natural Science Foundation(No.LY12H29001)Comparative Medicine Innovation Team of Zhejiang Chinese Medical University(No.XTD201301)
文摘Objective： To investigate the effect of total flavone of haw leaves（TFHL） on the expression of nuclear factor erythroid-2 related factor（Nrf2） and other related factors in nonalcoholic steatohepatitis（NASH） rats induced by high-fat diet and then to further discuss the mechanism of TFHL＇s prevention against NASH. Methods： High-fat diet was fed to 40 rats to establish the NASH model. Then model rats were intragastrically administrated with 40, 80, 160 mg/（kg·day） TFHL, respectively. The pathological changes of liver tissues in NASH rats were detected by oil red O and hematoxylin-eosin（HE） stainings. The expression of Nrf2 in rat liver was examined through immunohistochemistry. The level of 8-iso-prostaglandin F2α in serum was detected through enzyme linked immunosorbent assay（ELISA）. The mR NA and protein levels of Nrf2 and other related factors in liver tissue were measured by real-time reverse transcriptionpolymerase chain reaction and western blot. Results： Lipid deposition, hepatic steatosis, focal necrosis in lobular inflammation and ballooning degeneration were emerged in livers of NASH rats. The 8-iso-prostaglandin F2α in the serum of NASH rats increased significantly compared with the control group（P〈0.05）. The mR NA of Nrf2, hemeoxyenase1（HO-1） and the mR NA and protein levels of quinine oxidoreductase（NQO1） in NASH rats liver tissue showed a striking increase, while the mR NA levels of Keap1, r-glutamylcysteine synthethase（rG CS） and glutathione S-transferase（GST） were significantly decreased compared with the control group（P〈0.05）. After TFHL treatment, 8-iso-prostaglandin F2α level in serum significantly decreased, and Nrf2 mR NA and protein levels in hepatocytes nucleus enhanced compared with the model group（P〈0.05 or 0.01）. Meanwhile the Keap1 mR NA, the mR NA and protein levels of HO-1, NQO1 antibody, rG CS antibody, GST increased after TFHL treatment（P〈0.05 or 0.01）. Conclusions： Nrf2 and other related factors were involved in development of NASH, and they also served as an important part in its occurrence. By regulating expression of Nrf2 and other related factors, TFHL may play a role in antioxidative stress and prevention of NASH.
基金Supported by the National Research Foundation of Korea Grant funded by the Korea government(No.2014R1A2A2A01007375,No.2012R1A5A2A42671316)
文摘Objective： To investigate the cytoprotective effects of Saeng-kankunbi-tang（生肝健脾汤, SKT）, a herbal prescription consisting of Artemisia capillaris and Alisma canaliculatum, and its underlying mechanism involved. Methods： In mice, blood biochemistry and histopathology were assessed in carbon tetrachloride（CCl4）-induced oxidative hepatic injury in vivo. The animal groups included vehicle-treated control, CCl4, SKT 500 mg/（kg·day） CCl4＋SKT 200 or 500 mg/（kg·day）. In Hep G2 cell, tert-butyl hydroperoxide（t BHP） induced severe oxidative stress and mitochondrial dysfunction in vitro. The cyto-protective effects of SKT were determined by 3-（4,5-dimethylthiazol）-2,5-diphenyltetrazolium bromide（MTT） assay, fluorescence activated cell sorting analysis and western blotting. Results： The administration of SKT prevented liver damage induced by CCl4 in mice, by inhibition of hepatocyte degeneration and inflammatory cell infiltration as well as plasma parameters such as alanine aminotransferase（P〈0.01）. Moreover, treatment with t BHP induced hepatocyte death and cellular reactive oxygen species production in hepatocyte cell line. However, SKT pretreatment（30–300 μg/m L） reduced this cell death and oxidative stress（P〈0.01）. More importantly, SKT inhibited the ability of t BHP to induce changes in mitochondrial membrane transition in cell stained with rhodamine 123（P〈0.01）. Furthermore, treatment with SKT induced extracellular signal-regulated kinases-mediated nuclear factor erythroid-2-related factor 2（Nrf2） activation as well as the expressions of heme oxygenase 1 and glutamate-cystein ligase catalytic, Nrf2 target genes. Conclusion： SKT has the ability to protect hepatocyte against oxidative stress and mitochondrial damage mediated by Nrf2 activation.
