Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator o...Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.展开更多
AIM:To investigate the effect of prednisolone,a synthetic glucocorticoid used in inflammatory diseases,on the growth of cultured osteosarcoma cells.METHODS:Two osteosarcoma cell lines with different degree of differen...AIM:To investigate the effect of prednisolone,a synthetic glucocorticoid used in inflammatory diseases,on the growth of cultured osteosarcoma cells.METHODS:Two osteosarcoma cell lines with different degree of differentiation were used.SaOS2 show a rather mature phenotype,while U2 OS are negative for almost all osteoblastic markers.The cells were exposed to different concentrations of prednisolone(1-9 μmol/L) with or without antioxidants or the inhibitor of inducible nitric oxide synthase(i NOS) l-N6-(iminoethyl)-lysine-HCl(L-NIL).Cell growth was assessed by counting viable cells.The production of nitric oxide(NO) was measured in the conditioned media by the Griess method.The production of reactive oxygen species was quantified using 2'-7'-dichlorofluorescein diacetate.Western blot with specific antibodies against NOSs was performed on cell extracts.RESULTS:Prednisolone inhibited SaOS2 cell growth in a dose dependent manner.No significant effects were observed in U2OS.The inhibition of SaOS2 growth is not due to oxidative stress,because antioxidants do not rescue cell proliferation.Since high concentrations of NO inhibit bone formation,we also measured NO and found it induced in SaOS2,but not in U2 OS,exposed to prednisolone,because of the upregulation of i NOS as detected by western blot.Therefore,we treated SaOS2 with prednisolone in the presence or in the absence of L-NIL.L-NIL prevented NO release induced by prednisolone at all the concentrations apart from 9 μmol/L.At the same concentrations,we found that L-NIL rescued SaOS2 growth after exposure to prednisolone.In U2 OS cells,prednisolone did not induce NO production nor affected cell growth.All together,these data indicate that a link exists between increased amounts of NO and growth inhibition in response to prednisolone in SaOS2.CONCLUSION:Prednisolone inhibited SaOS2 proliferation by increasing the release of NO through the upregulation of i NOS,while no effect was exerted on U2OS.展开更多
This review describes the recent developments in the pathobiology of endothelial dysfunction(ED) in the context of cirrhosis with portal hypertension and defines novel strategies and potential targets for therapy. ED ...This review describes the recent developments in the pathobiology of endothelial dysfunction(ED) in the context of cirrhosis with portal hypertension and defines novel strategies and potential targets for therapy. ED has prognostic implications by predicting unfavourable early hepatic events and mortality in patients with portal hypertension and advanced liver diseases. EDcharacterised by an impaired bioactivity of nitric oxide(NO) within the hepatic circulation and is mainly due to decreased bioavailability of NO and accelerated degradation of NO with reactive oxygen species. Furthermore, elevated inflammatory markers also inhibit NO synthesis and causes ED in cirrhotic liver. Therefore, improvement of NO availability in the hepatic circulation can be beneficial for the improvement of endothelial dysfunction and associated portal hypertension in patients with cirrhosis. Furthermore, therapeutic agents that are identified in increasing NO bioavailability through improvement of hepatic endothelial nitric oxide synthase(e NOS) activity and reduction in hepatic asymmetric dimethylarginine, an endogenous modulator of e NOS and a key mediator of elevated intrahepatic vascular tone in cirrhosis would be interesting therapeutic approaches in patients with endothelial dysfunction and portal hypertension in advanced liver diseases.展开更多
OBJECTIVE:To investigate the efficacy of the Danlou Fang(DL)Traditional Chinese Medicine formula on microvascular obstruction(no-reflow)through the endothelial/inducible nitric oxide synthase(eNOS/iNOS)pathway in a ra...OBJECTIVE:To investigate the efficacy of the Danlou Fang(DL)Traditional Chinese Medicine formula on microvascular obstruction(no-reflow)through the endothelial/inducible nitric oxide synthase(eNOS/iNOS)pathway in a rat model.METHODS:Sprague-Dawley rats were subjected to 60 min of coronary artery occlusion(or sham procedure)followed by 2 h of reperfusion and were then divided into treatment groups:sham,model,DL(500 mg/kg),DL(500 mg/kg)+eNOS inhibitor L-nitroarginine(L-NNA;7.5 mg/kg),and sodium nitroprusside(SNP;0.5 mg/kg).There were 16 per group.Areas of no-reflow were determined by thioflavin S staining of heart tissue.Cardiac function was assessed by echocardiography.Myocardial enzymes and antioxidants in serum were measured and analyzed.The relative protein expression levels of eNOS and iNOS were determined by western blotting.RESULTS:DL had a myocardial protective effect on myocardial reperfusion and reduced the area of no-reflow.The serum levels of creatine kinase(CK),myocardial CK isoenzyme CK-MB,and lactate dehydrogenase were significantly lower in the DL group than in the model(P<0.05).DL treatment also decreased the serum content of malondialdehyde and reactive oxygen species(ROS),increased the activity of superoxide dismutase and nitric oxide,and promoted eNOS expression(P<0.05)while lowering iNOS expression.CONCLUSION:DL reduced the area of no-reflow and had a myocardial protective effect that may be associated with the eNOS/iNOS pathway.展开更多
Background: The production of endothelial-derived factors induces either vasoconstriction or vasodilation;nitric oxide (NO) is the most distinguished relaxing factor. Endothelial dysfunction is associated with hyperte...Background: The production of endothelial-derived factors induces either vasoconstriction or vasodilation;nitric oxide (NO) is the most distinguished relaxing factor. Endothelial dysfunction is associated with hypertension. The partial loss in the NO-promoted vasodilation is due to its decreased bioavailability and/or to an activity reduction of endothelium NO synthase (eNOS). Reactive oxygen species (ROS), present in oxidative stress, seize NO and diminish its bioavailability. Transresveratrol (RESV) has been proved to increase NO and eNOS levels. Thus, RESV could be capable of improving NO dependent vascular relaxation on aortic rings isolated from treated 2K-1C animals through ROS damage reduction. Aim: Evaluate the effects of RESV treatment on the relaxation of aortic rings isolated from treated 2K-1C rats while focusing on the effects of the treatment on systolic blood pressure. Methods: Male Wistar rats (180 g) were grouped: two 2K-1C and two Sham groups, one of each was treated with RESV (20 mg/kg, gavage) dissolved in Tween 80 and one of each was treated with water plus Tween 80 (control) for six weeks. The rats had their systolic blood pressure (SBP) measured before and after the treatments. Vascular reactivity studies were conducted in order to observe and compare acetylcholine (ACh)-induced relaxations in the presence and absence of the NOS inhibitor L-NAME (10-4 mol/L). Results: SBP for 2K-1C was significantly reduced in the treated group (179.13 ± 4.90 mmHg, n = 23) when compared to the untreated group (196.66 ± 6.06 mmHg, n = 15, p < 0.01). The maximum relaxation of aortic rings isolated from the 2K-1C treated group showed a higher efficacy (116.63% ± 1.72%, n = 12) than that from the untreated group (85.97% ± 0.69%, n = 6, p < 0.001);L-NAME exposure was responsible for a significant decrease in each group’s maximum relaxation efficacy. Conclusions: SBP reduction observed after RESV treatment in rat renal hypertension could be due to the reestablishment of vascular relaxation depend of NO.展开更多
Important roles for reactive oxygen species （ROS） in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular function...Important roles for reactive oxygen species （ROS） in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular functions. However, enhanced ROS production as a result of the activation of nicotinamide adenine dinucleotide phosphate （NADPH） oxidase contributes significantly to the pathogeneses of vascular diseases. Although it has become evident that increased ROS is associated with erectile dysfunction （ED）, the sources of ROS in the penis remain largely unknown. In recent years, emergent evidence suggests the possible role of NADPH oxidase in inducing ED. In this review, we examine the relationship between ROS and ED in different disease models and discuss the current evidence basis for NADPH oxidase-derive＇d ROS in ED.展开更多
Objective To evaluate the antioxidant potential in herbal extract barks of five therapeutically important medicinal plants native to India, i.e. Crataeva nurvala Buch.-Ham., Buchanania lanzan Spreng., Aegle marmelos C...Objective To evaluate the antioxidant potential in herbal extract barks of five therapeutically important medicinal plants native to India, i.e. Crataeva nurvala Buch.-Ham., Buchanania lanzan Spreng., Aegle marmelos Corr., Dalbergia sissoo Roxb. ex DC., and Cedrela toona Roxb. Methods Standardized aqueous alcoholic extracts from the selected barks having different target radicals, such as superoxide radical, nitric oxide, ABTS radical, and peroxidative decomposition of phospholipids, were prepared and screened by multiple in vitro assays. These extracts were also tested for total phenolic and tannin content and correlated with antioxidant capacity. Results Total phenolic and tannin contents were found to be the highest in C. nurvala （195 GAE mg/g and 218.3 mg/g CE）. SOD mimetic activity was found to be the highest in Crataeva nurvula, although all barks showed activity more than IO3 units/mg extract. Lipid peroxidation inhibitory potential was found to be the highest in Crataeva nurvala （83.4% inhibition of MDA formation/10 μg extract）, and also showed a comparatively high NO quenching capacity （45.5% per 10 μg extract）. The highest NO quenching potential was found in Aegle marmelos （47.3% per 10 μg extract）. Cedrela toona showed the lowest LPO inhibitory potential and NO quenching capacity （50.5% and 30.5%, respectively）. Buchanania lanzan, a medicinal plant extensively used for inflammatory disorders and Dalbergia sissoo also showed 72.5% and 69.1% LPO inhibitory potential/10 μg extract. Trolox equivalent antioxidant capacity ranged from 0.24 to 0.39 mmol/L TEAC/mg extract, indicating that all the barks tested had ABTS^＋ radical quenching capacity. Conclusion Bark of Crataeva nurvula has the highest antioxidant capacity and a positive correlation between antioxidant activity and their plendic content was found.展开更多
Ferroptosis is a type of programmed cell death dependent on iron.It is different from other forms of cell death such as apoptosis,classic necrosis and autophagy.Ferroptosis is involved in many neurodegenerative diseas...Ferroptosis is a type of programmed cell death dependent on iron.It is different from other forms of cell death such as apoptosis,classic necrosis and autophagy.Ferroptosis is involved in many neurodegenerative diseases.The role of ferroptosis in glutamate-induced neuronal toxicity is not fully understood.To test its toxicity,glutamate(1.25–20 mM)was applied to HT-22 cells for 12 to 48 hours.The optimal experimental conditions occurred at 12 hours after incubation with 5 mM glutamate.Cells were cultured with 3–12μM ferrostatin-1,an inhibitor of ferroptosis,for 12 hours before exposure to glutamate.The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Autophagy was determined by monodansylcadaverine staining and apoptosis by caspase 3 activity.Damage to cell structures was observed under light and by transmission electron microscopy.The release of lactate dehydrogenase was detected by the commercial kit.Reactive oxygen species were measured by flow cytometry.Glutathione peroxidase activity,superoxide dismutase activity and malondialdehyde level were detected by the appropriate commercial kit.Prostaglandin peroxidase synthase 2 and glutathione peroxidase 4 gene expression was detected by real-time quantitative polymerase chain reaction.Glutathione peroxidase 4 and nuclear factor erythroid-derived-like 2 protein expression was detected by western blot analysis.Results showed that ferrostatin-1 can significantly counter the effects of glutamate on HT-22 cells,improving the survival rate,reducing the release of lactate dehydrogenase and reducing the damage to mitochondrial ultrastructure.However,it did not affect the caspase-3 expression and monodansylcadaverine-positive staining in glutamate-injured HT-22 cells.Ferrostatin-1 reduced the levels of reactive oxygen species and malondialdehyde and enhanced superoxide dismutase activity.It decreased gene expression of prostaglandin peroxidase synthase 2 and increased gene expression of glutathione peroxidase 4 and protein expressions of glutathione peroxidase 4 and nuclear factor(erythroid-derived)-like 2 in glutamate-injured HT-22 cells.Treatment of cultured cells with the apoptosis inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone(2–8μM),autophagy inhibitor 3-methyladenine(100–400μM)or necrosis inhibitor necrostatin-1(10–40μM)had no effect on glutamate induced cell damage.However,the iron chelator deferoxamine mesylate salt inhibited glutamate induced cell death.Thus,the results suggested that ferroptosis is caused by glutamate-induced toxicity and that ferrostatin-1 protects HT-22 cells from glutamate-induced oxidative toxicity by inhibiting the oxidative stress.展开更多
The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause o...The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause of morbidity and mortality.The cardiovascular diseases that accompany diabetes include angina,myocardial infarction,stroke,peripheral artery disease,and congestive heart failure.Among the various risk factors generated secondary to hyperglycemic situations,advanced glycation end products(AGEs)are one of the important targets for future diagnosis and prevention of diabetes.In the last decade,AGEs have drawn a lot of attention due to their involvement in diabetic pathophysiology.AGEs can be derived exogenously and endogenously through various pathways.These are a nonhomogeneous,chemically diverse group of compounds formed nonenzymatically by condensation between carbonyl groups of reducing sugars and free amino groups of protein,lipids,and nucleic acid.AGEs mediate their pathological effects at the cellular and extracellular levels by multiple pathways.At the cellular level,they activate signaling cascades via the receptor for AGEs and initiate a complex series of intracellular signaling resulting in reactive oxygen species generation,inflammation,cellular proliferation,and fibrosis that may possibly exacerbate the damaging effects on cardiac functions in diabetics.AGEs also cause covalent modifications and cross-linking of serum and extracellular matrix proteins;altering their structure,stability,and functions.Early diagnosis of diabetes may prevent its progression to complications and decrease its associated comorbidities.In the present review,we recapitulate the role of AGEs as a crucial mediator of hyperglycemia-mediated detrimental effects in diabetes-associated complications.Furthermore,this review presents an overview of future perspectives for new therapeutic interventions to ameliorate cardiovascular complications in diabetes.展开更多
Nitric oxide （NO） plays important roles in diverse physiological processes in plants. NO can provoke both beneficial and harmful effects, which depend on the concentration and location of NO in plant cells. This rev...Nitric oxide （NO） plays important roles in diverse physiological processes in plants. NO can provoke both beneficial and harmful effects, which depend on the concentration and location of NO in plant cells. This review is focused on NO synthesis and the functions of NO in plant responses to abiotic environmental stresses. Abiotic stresses mostly induce NO production in plants. NO alleviates the harmfulness of reactive oxygen species, and reacts with other target molecules, and regulates the expression of stress responsive genes under various stress conditions.展开更多
Nitric oxide （NO） is a gaseous reactive oxygen species （ROS） that has evolved as a signaling hormone in many physiological processes in animals. In plants it has been demonstrated to be a crucial regulator of deve...Nitric oxide （NO） is a gaseous reactive oxygen species （ROS） that has evolved as a signaling hormone in many physiological processes in animals. In plants it has been demonstrated to be a crucial regulator of development, acting as a signaling molecule present at each step of the plant life cycle. NO has also been implicated as a signal in biotic and abiotic responses of plants to the environment. Remarkably, despite this plethora of effects and functional relationships, the fundamental knowledge of NO production, sensing, and transduction in plants remains largely unknown or inadequately characterized. In this review we cover the current understanding of NO production, perception, and action in different physiological sce- narios. We especially address the issues of enzymatic and chemical generation of NO in plants, NO sensing and downstream signaling, namely the putative cGMP and Ca^2＋ pathways, ion-channel activity modulation, gene expression regulation, and the interface with other ROS, which can have a profound effect on both NO accumulation and function. We also focus on the importance of NO in cell-cell communication during developmental processes and sexual reproduction, namely in pollen tube guidance and embryo sac fertilization, pathogen defense, and responses to abiotic stress.展开更多
The possible association with nitric oxide （NO） and ascorbate-glutathione （AsA-GSH） cycle in regulating aluminum （Al） tolerance of wheat （Triticum aestivum L.） was investigated using two genotypes with differe...The possible association with nitric oxide （NO） and ascorbate-glutathione （AsA-GSH） cycle in regulating aluminum （Al） tolerance of wheat （Triticum aestivum L.） was investigated using two genotypes with different Al resistance. Exposure to Al inhibited root elongation, and triggered lipid peroxidation and oxidation of AsA to dehydroascorbate and GSH to glutathione disulfide in wheat roots. Exogenous NO significantly increased endogenous NO levels, and subsequently al eviated Al-induced inhibition of root elongation and oxidation of AsA and GSH to maintain the redox molecules in the reduced form in both wheat genotypes. Under Al stress, significantly increased activities and gene transcriptional levels of ascorbate peroxi-dase, glutathione reductase, and dehydroascorbate reductase, were observed in the root tips of the Al-tolerant genotype Jian-864. Nitric oxide application enhanced the activity and gene transcriptional level of these enzymes in both wheat geno-types. g-Glutamylcysteine synthetase was not significantly affected by Al or NO, but NO treatments increased the activity of glutathione peroxidase and glutathione S-transferase to a greater extent than the Al-treated wheat seedlings. Proline was significantly decreased by Al, while it was not affected by NO. These results clearly suggest that NO protects wheat root against Al-induced oxidative stress, possibly through its regulation of the AsA-GSH cycle.展开更多
Nitric oxide(NO)has emerged as an important signal molecule in plants,having myriad roles in plant devel-opment.In addition,NO also orchestrates both biotic and abiotic stress responses,during which intensive cellular...Nitric oxide(NO)has emerged as an important signal molecule in plants,having myriad roles in plant devel-opment.In addition,NO also orchestrates both biotic and abiotic stress responses,during which intensive cellular metabolic reprogramming occurs.Integral to these responses is the location of NO biosynthetic and scavenging pathways in diverse cellular compartments,enabling plants to effectively organize signal transduction pathways.NO regulates plant metabolism and,in turn,metabolic pathways reciprocally regu-late NO accumulation and function.Thus,these diverse cellular processes are inextricably linked.This re-view addresses the numerous redox pathways,located in the various subcellular compartments that pro-duce NO,in addition to the mechanisms underpinning NO scavenging.We focus on how this molecular dance is integrated into the metabolic state of the cell.Within this context,a reciprocal relationship be-tween NO accumulation and metabolite production is often apparent.We also showcase cellular pathways,including those associated with nitrate reduction,that provide evidence for this integration of NO function and metabolism.Finally,we discuss the potential importance of the biochemical reactions governing NO levels in determining plant responses to a changing environment.展开更多
基金This study was supported in part by grants from the National Natural Science Foundation of China （No. 30571994, No. 30570713 and No. 30630032）.
文摘Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.
文摘AIM:To investigate the effect of prednisolone,a synthetic glucocorticoid used in inflammatory diseases,on the growth of cultured osteosarcoma cells.METHODS:Two osteosarcoma cell lines with different degree of differentiation were used.SaOS2 show a rather mature phenotype,while U2 OS are negative for almost all osteoblastic markers.The cells were exposed to different concentrations of prednisolone(1-9 μmol/L) with or without antioxidants or the inhibitor of inducible nitric oxide synthase(i NOS) l-N6-(iminoethyl)-lysine-HCl(L-NIL).Cell growth was assessed by counting viable cells.The production of nitric oxide(NO) was measured in the conditioned media by the Griess method.The production of reactive oxygen species was quantified using 2'-7'-dichlorofluorescein diacetate.Western blot with specific antibodies against NOSs was performed on cell extracts.RESULTS:Prednisolone inhibited SaOS2 cell growth in a dose dependent manner.No significant effects were observed in U2OS.The inhibition of SaOS2 growth is not due to oxidative stress,because antioxidants do not rescue cell proliferation.Since high concentrations of NO inhibit bone formation,we also measured NO and found it induced in SaOS2,but not in U2 OS,exposed to prednisolone,because of the upregulation of i NOS as detected by western blot.Therefore,we treated SaOS2 with prednisolone in the presence or in the absence of L-NIL.L-NIL prevented NO release induced by prednisolone at all the concentrations apart from 9 μmol/L.At the same concentrations,we found that L-NIL rescued SaOS2 growth after exposure to prednisolone.In U2 OS cells,prednisolone did not induce NO production nor affected cell growth.All together,these data indicate that a link exists between increased amounts of NO and growth inhibition in response to prednisolone in SaOS2.CONCLUSION:Prednisolone inhibited SaOS2 proliferation by increasing the release of NO through the upregulation of i NOS,while no effect was exerted on U2OS.
基金Supported by The Department of Biotechnology-Ramalingaswami Fellowship 5 years grant from the Government of India
文摘This review describes the recent developments in the pathobiology of endothelial dysfunction(ED) in the context of cirrhosis with portal hypertension and defines novel strategies and potential targets for therapy. ED has prognostic implications by predicting unfavourable early hepatic events and mortality in patients with portal hypertension and advanced liver diseases. EDcharacterised by an impaired bioactivity of nitric oxide(NO) within the hepatic circulation and is mainly due to decreased bioavailability of NO and accelerated degradation of NO with reactive oxygen species. Furthermore, elevated inflammatory markers also inhibit NO synthesis and causes ED in cirrhotic liver. Therefore, improvement of NO availability in the hepatic circulation can be beneficial for the improvement of endothelial dysfunction and associated portal hypertension in patients with cirrhosis. Furthermore, therapeutic agents that are identified in increasing NO bioavailability through improvement of hepatic endothelial nitric oxide synthase(e NOS) activity and reduction in hepatic asymmetric dimethylarginine, an endogenous modulator of e NOS and a key mediator of elevated intrahepatic vascular tone in cirrhosis would be interesting therapeutic approaches in patients with endothelial dysfunction and portal hypertension in advanced liver diseases.
文摘OBJECTIVE:To investigate the efficacy of the Danlou Fang(DL)Traditional Chinese Medicine formula on microvascular obstruction(no-reflow)through the endothelial/inducible nitric oxide synthase(eNOS/iNOS)pathway in a rat model.METHODS:Sprague-Dawley rats were subjected to 60 min of coronary artery occlusion(or sham procedure)followed by 2 h of reperfusion and were then divided into treatment groups:sham,model,DL(500 mg/kg),DL(500 mg/kg)+eNOS inhibitor L-nitroarginine(L-NNA;7.5 mg/kg),and sodium nitroprusside(SNP;0.5 mg/kg).There were 16 per group.Areas of no-reflow were determined by thioflavin S staining of heart tissue.Cardiac function was assessed by echocardiography.Myocardial enzymes and antioxidants in serum were measured and analyzed.The relative protein expression levels of eNOS and iNOS were determined by western blotting.RESULTS:DL had a myocardial protective effect on myocardial reperfusion and reduced the area of no-reflow.The serum levels of creatine kinase(CK),myocardial CK isoenzyme CK-MB,and lactate dehydrogenase were significantly lower in the DL group than in the model(P<0.05).DL treatment also decreased the serum content of malondialdehyde and reactive oxygen species(ROS),increased the activity of superoxide dismutase and nitric oxide,and promoted eNOS expression(P<0.05)while lowering iNOS expression.CONCLUSION:DL reduced the area of no-reflow and had a myocardial protective effect that may be associated with the eNOS/iNOS pathway.
文摘Background: The production of endothelial-derived factors induces either vasoconstriction or vasodilation;nitric oxide (NO) is the most distinguished relaxing factor. Endothelial dysfunction is associated with hypertension. The partial loss in the NO-promoted vasodilation is due to its decreased bioavailability and/or to an activity reduction of endothelium NO synthase (eNOS). Reactive oxygen species (ROS), present in oxidative stress, seize NO and diminish its bioavailability. Transresveratrol (RESV) has been proved to increase NO and eNOS levels. Thus, RESV could be capable of improving NO dependent vascular relaxation on aortic rings isolated from treated 2K-1C animals through ROS damage reduction. Aim: Evaluate the effects of RESV treatment on the relaxation of aortic rings isolated from treated 2K-1C rats while focusing on the effects of the treatment on systolic blood pressure. Methods: Male Wistar rats (180 g) were grouped: two 2K-1C and two Sham groups, one of each was treated with RESV (20 mg/kg, gavage) dissolved in Tween 80 and one of each was treated with water plus Tween 80 (control) for six weeks. The rats had their systolic blood pressure (SBP) measured before and after the treatments. Vascular reactivity studies were conducted in order to observe and compare acetylcholine (ACh)-induced relaxations in the presence and absence of the NOS inhibitor L-NAME (10-4 mol/L). Results: SBP for 2K-1C was significantly reduced in the treated group (179.13 ± 4.90 mmHg, n = 23) when compared to the untreated group (196.66 ± 6.06 mmHg, n = 15, p < 0.01). The maximum relaxation of aortic rings isolated from the 2K-1C treated group showed a higher efficacy (116.63% ± 1.72%, n = 12) than that from the untreated group (85.97% ± 0.69%, n = 6, p < 0.001);L-NAME exposure was responsible for a significant decrease in each group’s maximum relaxation efficacy. Conclusions: SBP reduction observed after RESV treatment in rat renal hypertension could be due to the reestablishment of vascular relaxation depend of NO.
文摘Important roles for reactive oxygen species （ROS） in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular functions. However, enhanced ROS production as a result of the activation of nicotinamide adenine dinucleotide phosphate （NADPH） oxidase contributes significantly to the pathogeneses of vascular diseases. Although it has become evident that increased ROS is associated with erectile dysfunction （ED）, the sources of ROS in the penis remain largely unknown. In recent years, emergent evidence suggests the possible role of NADPH oxidase in inducing ED. In this review, we examine the relationship between ROS and ED in different disease models and discuss the current evidence basis for NADPH oxidase-derive＇d ROS in ED.
文摘Objective To evaluate the antioxidant potential in herbal extract barks of five therapeutically important medicinal plants native to India, i.e. Crataeva nurvala Buch.-Ham., Buchanania lanzan Spreng., Aegle marmelos Corr., Dalbergia sissoo Roxb. ex DC., and Cedrela toona Roxb. Methods Standardized aqueous alcoholic extracts from the selected barks having different target radicals, such as superoxide radical, nitric oxide, ABTS radical, and peroxidative decomposition of phospholipids, were prepared and screened by multiple in vitro assays. These extracts were also tested for total phenolic and tannin content and correlated with antioxidant capacity. Results Total phenolic and tannin contents were found to be the highest in C. nurvala （195 GAE mg/g and 218.3 mg/g CE）. SOD mimetic activity was found to be the highest in Crataeva nurvula, although all barks showed activity more than IO3 units/mg extract. Lipid peroxidation inhibitory potential was found to be the highest in Crataeva nurvala （83.4% inhibition of MDA formation/10 μg extract）, and also showed a comparatively high NO quenching capacity （45.5% per 10 μg extract）. The highest NO quenching potential was found in Aegle marmelos （47.3% per 10 μg extract）. Cedrela toona showed the lowest LPO inhibitory potential and NO quenching capacity （50.5% and 30.5%, respectively）. Buchanania lanzan, a medicinal plant extensively used for inflammatory disorders and Dalbergia sissoo also showed 72.5% and 69.1% LPO inhibitory potential/10 μg extract. Trolox equivalent antioxidant capacity ranged from 0.24 to 0.39 mmol/L TEAC/mg extract, indicating that all the barks tested had ABTS^＋ radical quenching capacity. Conclusion Bark of Crataeva nurvula has the highest antioxidant capacity and a positive correlation between antioxidant activity and their plendic content was found.
文摘Ferroptosis is a type of programmed cell death dependent on iron.It is different from other forms of cell death such as apoptosis,classic necrosis and autophagy.Ferroptosis is involved in many neurodegenerative diseases.The role of ferroptosis in glutamate-induced neuronal toxicity is not fully understood.To test its toxicity,glutamate(1.25–20 mM)was applied to HT-22 cells for 12 to 48 hours.The optimal experimental conditions occurred at 12 hours after incubation with 5 mM glutamate.Cells were cultured with 3–12μM ferrostatin-1,an inhibitor of ferroptosis,for 12 hours before exposure to glutamate.The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Autophagy was determined by monodansylcadaverine staining and apoptosis by caspase 3 activity.Damage to cell structures was observed under light and by transmission electron microscopy.The release of lactate dehydrogenase was detected by the commercial kit.Reactive oxygen species were measured by flow cytometry.Glutathione peroxidase activity,superoxide dismutase activity and malondialdehyde level were detected by the appropriate commercial kit.Prostaglandin peroxidase synthase 2 and glutathione peroxidase 4 gene expression was detected by real-time quantitative polymerase chain reaction.Glutathione peroxidase 4 and nuclear factor erythroid-derived-like 2 protein expression was detected by western blot analysis.Results showed that ferrostatin-1 can significantly counter the effects of glutamate on HT-22 cells,improving the survival rate,reducing the release of lactate dehydrogenase and reducing the damage to mitochondrial ultrastructure.However,it did not affect the caspase-3 expression and monodansylcadaverine-positive staining in glutamate-injured HT-22 cells.Ferrostatin-1 reduced the levels of reactive oxygen species and malondialdehyde and enhanced superoxide dismutase activity.It decreased gene expression of prostaglandin peroxidase synthase 2 and increased gene expression of glutathione peroxidase 4 and protein expressions of glutathione peroxidase 4 and nuclear factor(erythroid-derived)-like 2 in glutamate-injured HT-22 cells.Treatment of cultured cells with the apoptosis inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone(2–8μM),autophagy inhibitor 3-methyladenine(100–400μM)or necrosis inhibitor necrostatin-1(10–40μM)had no effect on glutamate induced cell damage.However,the iron chelator deferoxamine mesylate salt inhibited glutamate induced cell death.Thus,the results suggested that ferroptosis is caused by glutamate-induced toxicity and that ferrostatin-1 protects HT-22 cells from glutamate-induced oxidative toxicity by inhibiting the oxidative stress.
文摘The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause of morbidity and mortality.The cardiovascular diseases that accompany diabetes include angina,myocardial infarction,stroke,peripheral artery disease,and congestive heart failure.Among the various risk factors generated secondary to hyperglycemic situations,advanced glycation end products(AGEs)are one of the important targets for future diagnosis and prevention of diabetes.In the last decade,AGEs have drawn a lot of attention due to their involvement in diabetic pathophysiology.AGEs can be derived exogenously and endogenously through various pathways.These are a nonhomogeneous,chemically diverse group of compounds formed nonenzymatically by condensation between carbonyl groups of reducing sugars and free amino groups of protein,lipids,and nucleic acid.AGEs mediate their pathological effects at the cellular and extracellular levels by multiple pathways.At the cellular level,they activate signaling cascades via the receptor for AGEs and initiate a complex series of intracellular signaling resulting in reactive oxygen species generation,inflammation,cellular proliferation,and fibrosis that may possibly exacerbate the damaging effects on cardiac functions in diabetics.AGEs also cause covalent modifications and cross-linking of serum and extracellular matrix proteins;altering their structure,stability,and functions.Early diagnosis of diabetes may prevent its progression to complications and decrease its associated comorbidities.In the present review,we recapitulate the role of AGEs as a crucial mediator of hyperglycemia-mediated detrimental effects in diabetes-associated complications.Furthermore,this review presents an overview of future perspectives for new therapeutic interventions to ameliorate cardiovascular complications in diabetes.
基金Supported by the State Key Basic Research and Development Plan of China(2006CB100100)a grant from the Program for New Century Excellent Talents from the Ministry of Education of China to L.M. Fan.
文摘Nitric oxide （NO） plays important roles in diverse physiological processes in plants. NO can provoke both beneficial and harmful effects, which depend on the concentration and location of NO in plant cells. This review is focused on NO synthesis and the functions of NO in plant responses to abiotic environmental stresses. Abiotic stresses mostly induce NO production in plants. NO alleviates the harmfulness of reactive oxygen species, and reacts with other target molecules, and regulates the expression of stress responsive genes under various stress conditions.
文摘Nitric oxide （NO） is a gaseous reactive oxygen species （ROS） that has evolved as a signaling hormone in many physiological processes in animals. In plants it has been demonstrated to be a crucial regulator of development, acting as a signaling molecule present at each step of the plant life cycle. NO has also been implicated as a signal in biotic and abiotic responses of plants to the environment. Remarkably, despite this plethora of effects and functional relationships, the fundamental knowledge of NO production, sensing, and transduction in plants remains largely unknown or inadequately characterized. In this review we cover the current understanding of NO production, perception, and action in different physiological sce- narios. We especially address the issues of enzymatic and chemical generation of NO in plants, NO sensing and downstream signaling, namely the putative cGMP and Ca^2＋ pathways, ion-channel activity modulation, gene expression regulation, and the interface with other ROS, which can have a profound effect on both NO accumulation and function. We also focus on the importance of NO in cell-cell communication during developmental processes and sexual reproduction, namely in pollen tube guidance and embryo sac fertilization, pathogen defense, and responses to abiotic stress.
基金supported by the National Basic Research Program (973 Program) of China (2013CB127403)National Natural Science Foundation of China (31272237,30771292)+1 种基金the Foundation for University Ph.D.Granting Disciplines of the Ministry of Education (20120101110130)IPNI
文摘The possible association with nitric oxide （NO） and ascorbate-glutathione （AsA-GSH） cycle in regulating aluminum （Al） tolerance of wheat （Triticum aestivum L.） was investigated using two genotypes with different Al resistance. Exposure to Al inhibited root elongation, and triggered lipid peroxidation and oxidation of AsA to dehydroascorbate and GSH to glutathione disulfide in wheat roots. Exogenous NO significantly increased endogenous NO levels, and subsequently al eviated Al-induced inhibition of root elongation and oxidation of AsA and GSH to maintain the redox molecules in the reduced form in both wheat genotypes. Under Al stress, significantly increased activities and gene transcriptional levels of ascorbate peroxi-dase, glutathione reductase, and dehydroascorbate reductase, were observed in the root tips of the Al-tolerant genotype Jian-864. Nitric oxide application enhanced the activity and gene transcriptional level of these enzymes in both wheat geno-types. g-Glutamylcysteine synthetase was not significantly affected by Al or NO, but NO treatments increased the activity of glutathione peroxidase and glutathione S-transferase to a greater extent than the Al-treated wheat seedlings. Proline was significantly decreased by Al, while it was not affected by NO. These results clearly suggest that NO protects wheat root against Al-induced oxidative stress, possibly through its regulation of the AsA-GSH cycle.
基金supported by SERB core grant CRG/2019/004534 and DBT project BT/PR23711/BPA/118/343/2017.Work on vitamin Bp and N meta-bolism in the labs of KJ.G.and T.B.F.is supported by an Indo-Swiss Joint Aesearch Programme on Blue Siy Research DBTIN/Swiss/47/JGKV 2018-19 and IZLZ3.183193.Work on nitric oxide in the G.J.L.lab is sup-ported by the BSAC,the Darwin Trust,and the Wellcome Tust.Work in the lab ofT.B.F.is supported by the SNF(grant 31003A-141117/1)and the University of Geneva.KJG.and A.R.F.acknowledge support from DST-DAAD project INT/FRG/DAAD/P-07/2018.
文摘Nitric oxide(NO)has emerged as an important signal molecule in plants,having myriad roles in plant devel-opment.In addition,NO also orchestrates both biotic and abiotic stress responses,during which intensive cellular metabolic reprogramming occurs.Integral to these responses is the location of NO biosynthetic and scavenging pathways in diverse cellular compartments,enabling plants to effectively organize signal transduction pathways.NO regulates plant metabolism and,in turn,metabolic pathways reciprocally regu-late NO accumulation and function.Thus,these diverse cellular processes are inextricably linked.This re-view addresses the numerous redox pathways,located in the various subcellular compartments that pro-duce NO,in addition to the mechanisms underpinning NO scavenging.We focus on how this molecular dance is integrated into the metabolic state of the cell.Within this context,a reciprocal relationship be-tween NO accumulation and metabolite production is often apparent.We also showcase cellular pathways,including those associated with nitrate reduction,that provide evidence for this integration of NO function and metabolism.Finally,we discuss the potential importance of the biochemical reactions governing NO levels in determining plant responses to a changing environment.
