Stimulus-specific accumulation of second messengers like reactive oxygen species （ROS） and Ca^＋ are central to many signaling and regulation processes in plants. However, mechanisms that govern the reciprocal inter...Stimulus-specific accumulation of second messengers like reactive oxygen species （ROS） and Ca^＋ are central to many signaling and regulation processes in plants. However, mechanisms that govern the reciprocal interrelation of Ca^＋ and ROS signaling are only beginning to emerge. NADPH oxidases of the respiratory burst oxidase homolog （RBOH） family are critical components contributing to the generation of ROS while Calcineurin B-like （CBL） Ca^＋ sensor proteins together with their interacting kinases （CIPKs） have been shown to function in many Ca^＋- signaling processes. In this study, we identify direct functional interactions between both signaling systems. We report that the CBL-interacting pro- tein kinase ClPK26 specifically interacts with the N-terminal domain of RBOHF in yeast two-hybrid analyses and with the full-length RBOHF protein in plant cells. In addition, CIPK26 phosphorylates RBOHF in vitro and co-expression of either CBL1 or CBL9 with CIPK26 strongly enhances ROS production by RBOHF in HEK293T cells. Together, these findings identify a direct interconnection between CBL-ClPK-mediated Ca^＋ signaling and ROS signaling in plants and provide evidence for a synergistic activation of the NADPH oxidase RBOHF by direct Ca^＋-binding to its EF-hands and Ca2＋-induced phospho-rylation by CBL1/9-ClPK26 complexes.展开更多
Energy metabolism is significantly reprogrammed in many human cancers, and these alterations confer many advantages to cancer cells, including the pro- motion of biosynthesis, ATP generation, detoxification and suppor...Energy metabolism is significantly reprogrammed in many human cancers, and these alterations confer many advantages to cancer cells, including the pro- motion of biosynthesis, ATP generation, detoxification and support of rapid proliferation. The pentose phos- phate pathway （PPP） is a major pathway for glucose catabolism. The PPP directs glucose flux to its oxi- dative branch and produces a reduced form of nico- tinamide adenine dinucleotide phosphate （NADPH）, an essential reductant in anabolic processes. It has become clear that the PPP plays a critical role in regulating cancer cell growth by supplying cells with not only ribose-5-phosphate but also NADPH for detoxification of intracellular reactive oxygen species, reductive biosynthesis and ribose biogenesis. Thus, alteration of the PPP contributes directly to cell pro- liferation, survival and senescence. Furthermore, recent studies have shown that the PPP is regulated oncogenically and/or metabolically by numerous fac- tors, including tumor suppressors, oncoproteins and intracellular metabolites. Dysregulation of PPP flux dramatically impacts cancer growth and survival. Therefore, a better understanding of how the PPP is reprogrammed and the mechanism underlying the balance between glycolysis and PPP flux in cancer will be valuable in developing therapeutic strategies targeting this pathway.展开更多
AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cir...AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cirrhosis was assessed by using NADPHdiaphorase (NADPH-d ) histochemical method.Concentration of NO in serum were measured byfluorometric assay. Mean arterial pressure(MAP), cardiac output (CO), cardiac index (CI),splanchnic vascular resistance (SVR ), andsplanchnic blood flow (SBF ) were alsodetermined using 5’CO-labeled microspheretechnique.RESULTS Intensity of NOS staining in theesophageal epithelium of cirrhotic rats wassignificantly stronger than that in controls.There was a NOS--positive staining area in theendothelia of esophageal submucosal vessels ofcirrhotic rats, but the NOS staining was negativein normal rats. NO concentration of serum incirrhotic rats were significantly higher incomparison with that of controls. Cirrhotic ratshad significantly lower MAP, SVR and higherSBF than those of the controls.CONCLUSION SPlanchnic hyperdynamiccirculatory state was observed in rats withcirrhosis. The endogenous NO may play animportant role in development of esophagealvarices and in changes of hemodynamics incirrhosis.展开更多
AIM:To investigate the effects of blueberry on hepatic fibrosis and NF-E2-related factor 2(Nrf2) transcription factor in rats.METHODS:Forty-five male Sprague-Dawley rats were randomly divided into control group(A);CCl...AIM:To investigate the effects of blueberry on hepatic fibrosis and NF-E2-related factor 2(Nrf2) transcription factor in rats.METHODS:Forty-five male Sprague-Dawley rats were randomly divided into control group(A);CCl4-induced hepatic fibrosis group(B);blueberry prevention group(C);Dan-shao-hua-xian capsule(DSHX) prevention group(D);and blueberry + DSHX prevention group(E).Liver fibrosis was induced in rats by subcutaneous injection of CCl4 and a high-lipid/low-protein diet for 8 wk(except the control group).The level of hyaluronic acid(HA) and alanine aminotransferase(ALT) in serum was examined.The activity of superoxide dismutase(SOD),glutathione-S-transferase(GST) and malondialdehyde(MDA) in liver homogenates was determined.The degree of hepatic fibrosis was evaluated by hematoxylin and eosin and Masson staining.Expression of Nrf2 and NADPH quinone oxidoreductase 1(Nqo1) was detected by real-time reversed transcribed-polymerase chain reaction,immunohistochemical techniques,and western blotting.RESULTS:Compared with group B,liver indices,levels of serum HA and ALT of groups C,D and E were reduced(liver indices:0.038 ± 0.008,0.036 ± 0.007,0.036 ± 0.005 vs 0.054 ± 0.009,P<0.05;HA:502.33 ± 110.57 ng/mL,524.25 ± 255.42 ng/mL,499.25 ± 198.10 ng/mL vs 828.50 ± 237.83 ng/mL,P<0.05;ALT:149.44 ± 16.51 U/L,136.88 ± 10.07 U/L,127.38 ± 11.03 U/L vs 203.25 ± 31.62 U/L,P<0.05),and SOD level was significantly higher,but MDA level was lower,in liver homogenates(SOD:1.36 ± 0.09 U/mg,1.42 ± 0.13 U/mg,1.50 ± 0.15 U/mg vs 1.08 ± 0.19 U/mg,P<0.05;MDA:0.294 ± 0.026 nmol/mg,0.285 ± 0.025 nmol/mg,0.284 ± 0.028 nmol/mg vs 0.335 ± 0.056 nmol/mg,P<0.05).Meanwhile,the stage of hepatic fibrosis was significantly weakened(P<0.05).Compared with group A,the activity of GST liver homogenates and expression levels of Nrf2 and Nqo1 in group B were elevated(P<0.05).The expression level of Nrf2 and Nqo1 in groups C,D,and E were increased as compared with group B,but the difference was not significant.CONCLUSION:Blueberry has pr展开更多
Heart disease is associated with increased sympathetic nerve activity and elevated levels of circulating catecholamines,resulting in chronic stimulation of the β-adrenergic receptors (β-AR) and consequent pathologic...Heart disease is associated with increased sympathetic nerve activity and elevated levels of circulating catecholamines,resulting in chronic stimulation of the β-adrenergic receptors (β-AR) and consequent pathological cardiac remodeling.Experimentally,chronic administration of the β-AR agonist isoproterenol (ISO) has been most commonly used to model β-AR-induced cardiac remodeling.However,it remains unclear whether β-AR-mediated cardiac remodeling and dysfunction differs between sustained versus pulsatile (intermittent) exposure to a β-agonist.Here,we compare the effects of intermittent versus sustained administration of ISO on cardiac remodeling and function in mice.Animals were administered 5 mg (kg d)-1 ISO for 2 weeks either by daily subcutaneous injection,or continuous infusion via an implanted osmotic minipump.Cardiac function and remodeling were determined by echocardiography,micromanometry and histology.Moreover,Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized to define the proteins and genes involved.Both sustained and intermittent administration of ISO resulted in a similar degree of cardiac hypertrophy (16% and 19%,respectively).However,mice receiving ISO by daily injection developed more severe ventricular systolic and diastolic dysfunction and myocardial fibrosis compared with mice receiving ISO via the osmotic minipump.The disparity in results between the delivery methods is suggested to be due,at least in part,to increased expression of fibrogenic factors,including connective tissue growth factor (CTGF) and NADPH oxidase (NOX4),in mice receiving intermittent application of ISO.In summary,compared with sustained exposure to a β-AR agonist,intermittent β-AR stimulation leads to more severe cardiac dysfunction and fibrosis.These findings not only further our understanding of β-AR function in the setting of cardiac pathophysiology,but also highlight that significant differences can result dependent upon the mode of experimental β-AR stimulation in 展开更多
Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseas...Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells. Methods Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method. Results Tea polyphenols of 0.4 ug/mL and 4.0 ug/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P<0.05), and up-regulated the expressions of catalase (P<0.05). Conclusions Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.展开更多
Accumulation of plasma advanced oxidation protein products(AOPPs) promotes progression of proteinuria and glomerulo-sclerosis.To investigate the molecular basis of AOPPs-induced proteinuria,normal Sprague-Dawley rats ...Accumulation of plasma advanced oxidation protein products(AOPPs) promotes progression of proteinuria and glomerulo-sclerosis.To investigate the molecular basis of AOPPs-induced proteinuria,normal Sprague-Dawley rats were treated with AOPPs-modified rat serum albumin.The expression of glomerular podocyte slit diaphragm(PSD)-associated proteins,nephrin and podocin,was significantly decreased coincident with the onset of albuminuria in rats treated with AOPPs.Chronic inhibi-tion of NADPH oxidase by apocynin prevented down-regulation of nephrin and podocin and decreased albuminuria in AOPPs-challenged rats.This suggested that accumulation of AOPPs promotes proteinuria,possibly via down-regulating the expression of PSD-associated proteins.展开更多
文摘Stimulus-specific accumulation of second messengers like reactive oxygen species （ROS） and Ca^＋ are central to many signaling and regulation processes in plants. However, mechanisms that govern the reciprocal interrelation of Ca^＋ and ROS signaling are only beginning to emerge. NADPH oxidases of the respiratory burst oxidase homolog （RBOH） family are critical components contributing to the generation of ROS while Calcineurin B-like （CBL） Ca^＋ sensor proteins together with their interacting kinases （CIPKs） have been shown to function in many Ca^＋- signaling processes. In this study, we identify direct functional interactions between both signaling systems. We report that the CBL-interacting pro- tein kinase ClPK26 specifically interacts with the N-terminal domain of RBOHF in yeast two-hybrid analyses and with the full-length RBOHF protein in plant cells. In addition, CIPK26 phosphorylates RBOHF in vitro and co-expression of either CBL1 or CBL9 with CIPK26 strongly enhances ROS production by RBOHF in HEK293T cells. Together, these findings identify a direct interconnection between CBL-ClPK-mediated Ca^＋ signaling and ROS signaling in plants and provide evidence for a synergistic activation of the NADPH oxidase RBOHF by direct Ca^＋-binding to its EF-hands and Ca2＋-induced phospho-rylation by CBL1/9-ClPK26 complexes.
基金We apologize to those authors whose excellent work could not be cited due to space constraints. This work was supported by the Start-Up Package Fund from Tsinghua University to J.P. and the grant （Grants No. 2010CB912804 and 31030046 to WM） from National Natural Science Foundation of China.
文摘Energy metabolism is significantly reprogrammed in many human cancers, and these alterations confer many advantages to cancer cells, including the pro- motion of biosynthesis, ATP generation, detoxification and support of rapid proliferation. The pentose phos- phate pathway （PPP） is a major pathway for glucose catabolism. The PPP directs glucose flux to its oxi- dative branch and produces a reduced form of nico- tinamide adenine dinucleotide phosphate （NADPH）, an essential reductant in anabolic processes. It has become clear that the PPP plays a critical role in regulating cancer cell growth by supplying cells with not only ribose-5-phosphate but also NADPH for detoxification of intracellular reactive oxygen species, reductive biosynthesis and ribose biogenesis. Thus, alteration of the PPP contributes directly to cell pro- liferation, survival and senescence. Furthermore, recent studies have shown that the PPP is regulated oncogenically and/or metabolically by numerous fac- tors, including tumor suppressors, oncoproteins and intracellular metabolites. Dysregulation of PPP flux dramatically impacts cancer growth and survival. Therefore, a better understanding of how the PPP is reprogrammed and the mechanism underlying the balance between glycolysis and PPP flux in cancer will be valuable in developing therapeutic strategies targeting this pathway.
文摘AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cirrhosis was assessed by using NADPHdiaphorase (NADPH-d ) histochemical method.Concentration of NO in serum were measured byfluorometric assay. Mean arterial pressure(MAP), cardiac output (CO), cardiac index (CI),splanchnic vascular resistance (SVR ), andsplanchnic blood flow (SBF ) were alsodetermined using 5’CO-labeled microspheretechnique.RESULTS Intensity of NOS staining in theesophageal epithelium of cirrhotic rats wassignificantly stronger than that in controls.There was a NOS--positive staining area in theendothelia of esophageal submucosal vessels ofcirrhotic rats, but the NOS staining was negativein normal rats. NO concentration of serum incirrhotic rats were significantly higher incomparison with that of controls. Cirrhotic ratshad significantly lower MAP, SVR and higherSBF than those of the controls.CONCLUSION SPlanchnic hyperdynamiccirculatory state was observed in rats withcirrhosis. The endogenous NO may play animportant role in development of esophagealvarices and in changes of hemodynamics incirrhosis.
基金Supported by A grant from Foundation of High Level Talented Specialists of Guizhou Province,China,No. TZJF-200850a grant from Foundation of the Program for Tackling Key Problems of Guizhou Science and Technology Department,China,No. 2010GZ97666
文摘AIM:To investigate the effects of blueberry on hepatic fibrosis and NF-E2-related factor 2(Nrf2) transcription factor in rats.METHODS:Forty-five male Sprague-Dawley rats were randomly divided into control group(A);CCl4-induced hepatic fibrosis group(B);blueberry prevention group(C);Dan-shao-hua-xian capsule(DSHX) prevention group(D);and blueberry + DSHX prevention group(E).Liver fibrosis was induced in rats by subcutaneous injection of CCl4 and a high-lipid/low-protein diet for 8 wk(except the control group).The level of hyaluronic acid(HA) and alanine aminotransferase(ALT) in serum was examined.The activity of superoxide dismutase(SOD),glutathione-S-transferase(GST) and malondialdehyde(MDA) in liver homogenates was determined.The degree of hepatic fibrosis was evaluated by hematoxylin and eosin and Masson staining.Expression of Nrf2 and NADPH quinone oxidoreductase 1(Nqo1) was detected by real-time reversed transcribed-polymerase chain reaction,immunohistochemical techniques,and western blotting.RESULTS:Compared with group B,liver indices,levels of serum HA and ALT of groups C,D and E were reduced(liver indices:0.038 ± 0.008,0.036 ± 0.007,0.036 ± 0.005 vs 0.054 ± 0.009,P<0.05;HA:502.33 ± 110.57 ng/mL,524.25 ± 255.42 ng/mL,499.25 ± 198.10 ng/mL vs 828.50 ± 237.83 ng/mL,P<0.05;ALT:149.44 ± 16.51 U/L,136.88 ± 10.07 U/L,127.38 ± 11.03 U/L vs 203.25 ± 31.62 U/L,P<0.05),and SOD level was significantly higher,but MDA level was lower,in liver homogenates(SOD:1.36 ± 0.09 U/mg,1.42 ± 0.13 U/mg,1.50 ± 0.15 U/mg vs 1.08 ± 0.19 U/mg,P<0.05;MDA:0.294 ± 0.026 nmol/mg,0.285 ± 0.025 nmol/mg,0.284 ± 0.028 nmol/mg vs 0.335 ± 0.056 nmol/mg,P<0.05).Meanwhile,the stage of hepatic fibrosis was significantly weakened(P<0.05).Compared with group A,the activity of GST liver homogenates and expression levels of Nrf2 and Nqo1 in group B were elevated(P<0.05).The expression level of Nrf2 and Nqo1 in groups C,D,and E were increased as compared with group B,but the difference was not significant.CONCLUSION:Blueberry has pr
基金supported by theNational Basic Research Program of China (Grant No. 2011CB503903)the National Natural Science Foundation of China (Grant Nos.81030001 and 30971161)the International Cooperation and Exchange of the National Natural Science Foundation of China (Grant No.30910103902)
文摘Heart disease is associated with increased sympathetic nerve activity and elevated levels of circulating catecholamines,resulting in chronic stimulation of the β-adrenergic receptors (β-AR) and consequent pathological cardiac remodeling.Experimentally,chronic administration of the β-AR agonist isoproterenol (ISO) has been most commonly used to model β-AR-induced cardiac remodeling.However,it remains unclear whether β-AR-mediated cardiac remodeling and dysfunction differs between sustained versus pulsatile (intermittent) exposure to a β-agonist.Here,we compare the effects of intermittent versus sustained administration of ISO on cardiac remodeling and function in mice.Animals were administered 5 mg (kg d)-1 ISO for 2 weeks either by daily subcutaneous injection,or continuous infusion via an implanted osmotic minipump.Cardiac function and remodeling were determined by echocardiography,micromanometry and histology.Moreover,Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized to define the proteins and genes involved.Both sustained and intermittent administration of ISO resulted in a similar degree of cardiac hypertrophy (16% and 19%,respectively).However,mice receiving ISO by daily injection developed more severe ventricular systolic and diastolic dysfunction and myocardial fibrosis compared with mice receiving ISO via the osmotic minipump.The disparity in results between the delivery methods is suggested to be due,at least in part,to increased expression of fibrogenic factors,including connective tissue growth factor (CTGF) and NADPH oxidase (NOX4),in mice receiving intermittent application of ISO.In summary,compared with sustained exposure to a β-AR agonist,intermittent β-AR stimulation leads to more severe cardiac dysfunction and fibrosis.These findings not only further our understanding of β-AR function in the setting of cardiac pathophysiology,but also highlight that significant differences can result dependent upon the mode of experimental β-AR stimulation in
基金This study was supported in part by the Japan-China Sasakawa Medical Fellowship.
文摘Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells. Methods Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method. Results Tea polyphenols of 0.4 ug/mL and 4.0 ug/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P<0.05), and up-regulated the expressions of catalase (P<0.05). Conclusions Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.
基金supported by the National Natural Science Foundation of China (Grant Nos 30830056 and 30830056)the National Basic Research Program of China (Grant No 2006CB503904) to Dr HOU FanFan+1 种基金the National Natural Science Foundation of China (Grant No 30971382)the Natural Science Foundation of Guangdong Province (Grant No 06024402) to Dr LIANG Min
文摘Accumulation of plasma advanced oxidation protein products(AOPPs) promotes progression of proteinuria and glomerulo-sclerosis.To investigate the molecular basis of AOPPs-induced proteinuria,normal Sprague-Dawley rats were treated with AOPPs-modified rat serum albumin.The expression of glomerular podocyte slit diaphragm(PSD)-associated proteins,nephrin and podocin,was significantly decreased coincident with the onset of albuminuria in rats treated with AOPPs.Chronic inhibi-tion of NADPH oxidase by apocynin prevented down-regulation of nephrin and podocin and decreased albuminuria in AOPPs-challenged rats.This suggested that accumulation of AOPPs promotes proteinuria,possibly via down-regulating the expression of PSD-associated proteins.
