Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of a...Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.展开更多
Objective: Highland natives adapt well to the hypoxic environment at high altitude(HA). Several genes have been reported to be linked to HA adaptation. Previous studies showed that the endothelial nitric oxide synthas...Objective: Highland natives adapt well to the hypoxic environment at high altitude(HA). Several genes have been reported to be linked to HA adaptation. Previous studies showed that the endothelial nitric oxide synthase(ENOS) G894 T polymorphism contributed to the physiology and pathophysiology of humans at HA by regulating the production of NO. In this meta-analysis, we evaluate the association between the ENOS G894 T polymorphism and HA adaptation through analyzing the published data. Methods: We searched all relevant literature about the ENOS G894 T polymorphism and HA adaptation in Pub Med, Medline, and Embase before Step 2015. A random-effects model was applied(Revman 5.0), and study quality was assessed in duplicate. Six studies with 634 HA native cases and 621 low-altitude controls were included in this meta-analysis. Results: From the results, we observed that the wild-type allele G was significantly overrepresented in the HA groups(OR=1.85; 95% CI, 1.47–2.33; P<0.0001). In addition, the GG genotype was significantly associated with HA adaptation(OR=1.99; 95% CI, 1.54–2.57; P<0.0001). Conclusion: Our results showed that in 894 G allele carriers, the GG genotype might be a beneficial factor for HA adaptation through enhancing the level of NO. However, more studies were needed to confirm our findings due to the limited sample size.展开更多
3-hydroxy-3-methylgulutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies sug...3-hydroxy-3-methylgulutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies suggested that statins, besides lowering cholesterol, may protect vessels by enhancing the activity of endothelial nitric oxide synthase (eNOS). In the present study, we investigated if simvastatin increases eNOS activity through its phosphorylation in 293 cells (293-eNOS) with stable expression of eNOS. The results showed that incubation of 293-eNOS cells with simvastatin (10 μm/L) for 2 h significantly increased in the activity of eNOS as shown by the conversion of L-arginine to L-citrulline (2889.70±201.51 versus 5630.18+218.75 pmol/min . mg proteins) (P〈0.01). Western blotting revealed that simvastatin increased phosphorylation of eNOS at 1177 (ser) and also 495 (thr) but did not affect the overall expression of eNOS or inducible NOS. Further study found that simvastatin raised phosphorylation levels of Akt and AMPK, and such effect could be antagonized by Akt inhibitor or AMPK inhibitor. These results suggest that simvastatin could stimulate,the activity of eNOS via its phosphorylation by Akt and AMPK, which provides a new mechanism, other than lipid-lowering effect, for the cardiovascular protection of statins.展开更多
AIM: This study was designed to examine the hypothesis that gender differences in I/R injury are associated withendothelial cell nitric oxide synthase (eNOS)-derived nitric oxide (NO).METHODS: Wistar rats were randomi...AIM: This study was designed to examine the hypothesis that gender differences in I/R injury are associated withendothelial cell nitric oxide synthase (eNOS)-derived nitric oxide (NO).METHODS: Wistar rats were randomized into seven experimental groups (12 animals per group). Except for the sham operated groups, all rats were subjected to total liver ischemia for 40 min followed by reperfusion. All experimental groups received different treatments 45 min before the laparotomy. For each group, half of the animals (six) were used to investigate the survival; blood samples and liver tissues were obtained in the remaining six animals after 3 h of reperfusion to assess serum NO, alanine aminotransferase (ALT) and TNF-α levels, liver tissuemalondialdehyde (MDA) content, and severity of hepatic I/R injury.RESULTS: Basal serum NO levels in female sham operated (FS) group were nearly 1.5-fold of male sham operated (MS) group (66.7±11.0 μmol/L vs 45.3±10.1μmol/L, P<0.01). Although serum NO levels decreased significantly after hepatic I/R (P<0.01, vs sham operated groups), they were still significantly higher in female rat (F) group than in male rat (M) group (47.8±8.6 μmol/L vs 23.8±4.7 μmol/L, P<0.01). Serum ALT and TNF-α levels, and liver tissue MDA content were significantly lower in F group than in M group (370.5±46.4 U/L, 0.99±0.11 μg/L and 0.57±0.10 μmol/g vs668.7±78.7 U/L, 1.71±0.18 μg/Land 0.86±0.11 μmol/g, respectively, P<0.01). I/R induced significant injury to the liver both in M and F groups (P<0.01 vs sham operated groups). But the degree of hepatocyte injury was significantly milder in F group than in M group (P<0.05 and P<0.01). The median survival time was six days in F group and one day in M group. The overall survival rate was significantly higher in F group than in M group (P<0.05). When compared with male rats pretreated with saline (M group), pretreatment of male rats with 17-β- estradiol (E2) (M+E2 group) significantly increased serum NO levels and significantly decreased serum ALT and TNF-α levels, and liver tissue MDA content after I/R (P<0.01).The degree of hepatocyte injury was significantly decreased and the overall survival rate was significantly improved in M+E2 group than in M group (P<0.01 and P<0.05). TheNOS inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) treatment could completely abolish the protective effects of estrogen in both male and female rats. CONCLUSION: The protective effects afforded to female rats subjected to hepatic I/R are associated with eNOSderived NO.展开更多
Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of ather...Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of atherosclerosis by increasing endothelial adhesiveness.Here,we sought to investigate whether CTRP1 also influences vascular dilatory functions.展开更多
Objective: To investigate the relationship between the expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and angiogenesis in primary astrocytoma. Methods: Thirty-seven p...Objective: To investigate the relationship between the expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and angiogenesis in primary astrocytoma. Methods: Thirty-seven primary astrocytomas and 4 astrocytic hyperplasia samples were collected and divided into three groups according to histological grade. The expression of eNOS, VEGF and factor Ⅷ related antigen (FVIIIRAg) were assayed by immunohistochemistry. Microvascular density was assessed by FVIIIRAg immunoreactivity. The intensity of immunoreactivity was graded according to the percentage of positive tumor cells. Results: No eNOS and VEGF were expressed in the astrocytes and vascular endothelium in astrocytic hyperplasia.The expression of eNOS or VEGF was light in low-grade astrocytoma and strong in glioblastoma. eNOS expression in astrocytoma was very positively correlated with VEGF. eNOS and VEGF expression in anaplastic astrocytoma was median in contrast to the low grade astrocytoma and glioblastoma. Lower microvascular density was found in low grade astrocytoma than that in higher grade malignant ones. The expressions of eNOS and VEGF were correlated with microvascular density and tumor malignancy.Conclusion: This finding suggests that eNOS and VEGF may have cooperative effect in tumor angiogenesis and play an important role in the pathogenesis of primary astrocytoma.展开更多
Objective: To analyze the expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) and its relation...Objective: To analyze the expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) and its relation to angiogenesis. Methods: Tissue sections from 71 HCC patients were examined immunohistochemically for protein expression of iNOS, eNOS, and VEGF. Microvessal density (MVD) was counted by endothelial cells immunostained by anti-CD34 antibody. Results: Positive immunostaining for iNOS, eNOS was detected in 83.1% and 85.9% of HCC respectively. INOS and eNOS were not detected in normal hepatic tissue. MVD was 34.3±1.5/HP and 38.6±1.6/HP in HCC with positive staining for iNOS and VEGF while it was 31.2±2.8/HP, and 22.4±2.0/HP in HCC with negative staining for iNOS and VEGF (P<0.01). A correlation between NOS expression and VEGF in HCC was not observed. Conclusion: iNOS and eNOS may play a role in malignant transformation f post-hepatic cirrhosis. The expression of iNOS and VEGF favors angiogenesis of HCC.展开更多
The expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of the patients with pregnancy induced hypertension (PIH) was detected and its role in the pathogenesis of PIH was stud...The expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of the patients with pregnancy induced hypertension (PIH) was detected and its role in the pathogenesis of PIH was studied. The pathological changes in placental vessels were observed by HE staining. NO2-/NO3- , the stable metabolic end products of NO, was measured with nitrate reductase. The eNOS activity in placental tissues was assayed by spectrophotometry. Western blot analysis was applied to detect NOSTRIN expression. The incidence of thickening and fibronoid necrosis of placental vessels was significantly higher in women with PIH than in the normal group (P〈 0.01). The levels of placental NO2-/NO3- in PIH patients (27. 53±7.48 μmol/mg) were significantly lower than in normal group (54. 27±9.53 μmol/mg, P〈0.01). The activity of eNOS was significantly decreased in PIH group (12. 826±3.61 U/mg) as compared with that in normal group (21. 72±3.83 U/mg, P〈0.01). Western blot analysis revealed that both groups expressed 58 kD NOSTRIN, but the protein level was significantly higher in women with PIH than in the normal group (P〈0.01). A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in placental tissue of women with PIH (r=-0.57, P〈0.01). It was concluded that the level of NOSTRIN expression in placenta of women with PIH was increased, which may play an important role in the pathogenesis of PIH.展开更多
This study investigated the changes in human umbilical vein endothelial cells (HUVECs) induced by overexpression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) and its role in cellular injury. Reco...This study investigated the changes in human umbilical vein endothelial cells (HUVECs) induced by overexpression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) and its role in cellular injury. Recombinant NOSTRIN-expressing and empty vectors were transfected into cultured HUVECs, and factor Ⅷ-related antigen was examined by using immunohistochemical analysis. Growth curves were generated for both transfected and untransfected cells and these indicated that the prolifera- tive ability of cells overexpressing NOSTRIN was significantly decreased. The expression of NOSTRIN and eNOS proteins was detected by using Western blot analysis, endothelial NOS (eNOS) activity was assayed by using spectrophotometry, and NO2-/NO3- levels were measured usin~ nitrate reductase. Immunohistochemical analysis demonstrated that all groups expressed NOSTRIN in the plasma mem- brane and cytoplasm, and Western blot analysis confirmed that NOSTR1N levels were significantly higher in cells transfected with the NOSTR1N plasmid (P〈0.01). The activity of eNOS and the levels of NO2-/NO3 were significantly decreased in NOSTRIN overexpressing cells as compared with empty vector and untransfected cells (P〈0.01 and P〈0.01, respectively). Morphological and ultrastructural changes were observed under light and electron microscopy, and it was found that NOS- TRIN-overexpressing cells were elongated with deformities of the karyotheca, injury to the plasma membrane, increased lipids in the cytoplasm, and shortened microvilli. This study showed that overex- pression of NOSTRIN had a significant effect on eNOS activity in HUVECs and resulted in significant cellular damage.展开更多
AIM: To clarify how the endothelial nitric oxide synthase (eNOS, NOS3) make effect on outflow facility through the trabecular meshwork (TM). METHODS: Inhibition of NOS3 gene expression in human TM cells were co...AIM: To clarify how the endothelial nitric oxide synthase (eNOS, NOS3) make effect on outflow facility through the trabecular meshwork (TM). METHODS: Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC) cells were determined, still were the collagen, type IV, alpha 1 (COL4A1) and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS: The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION: Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1). Reduced NOS3 restrains the TM cell cycle progression at the G2/ M-phase transition and induced cell apoptosis.展开更多
Background: Low shear stress caused by disturbed or turbulent flow at arterial branch points is known to associate with atherosclerosis. However, shear stress at the venous valve location and its association with deep...Background: Low shear stress caused by disturbed or turbulent flow at arterial branch points is known to associate with atherosclerosis. However, shear stress at the venous valve location and its association with deep vein thrombosis are less understood due to the complex and poorly understood bi-directional flow in the valve pocket region. We investigated how venous endothelial cells respond to flow shear stress around the venous valve region using a novel in vitro system that mimics venous flow. Results: Human umbilical vein EAhy. 926 cells were cultured on a flexible silastic membrane that mimicked venous tissue. Confluent cells were exposed to sinusoidal uni-and bi-directional pulsatile shear stress (0.1 to 1 dyne/cm2) for up to 6 h. Western-blot analyses indicated that endothelial nitric oxide (eNOS) expression levels decreased regardless of all tested flow patterns, stress magnitude, and shearing time. In contrast, the expression levels of inhibitor of κB (kappa B) and α (alpha)-tubulin were unaffected by the shear stress. Conclusions: Our results indicate that shear stress causes a decrease specifically in eNOS expression, suggesting that it may play a significant role in regulating inflammation related protein expression in endothelial cells.展开更多
With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic...With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.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
AIM:To study the cell-type specific subcellular distribution of the three isoforms of nitric oxide synthase(NOS) in the rat duodenum.METHODS:Postembedding immunoelectronmicroscopy was performed,in which primary antibo...AIM:To study the cell-type specific subcellular distribution of the three isoforms of nitric oxide synthase(NOS) in the rat duodenum.METHODS:Postembedding immunoelectronmicroscopy was performed,in which primary antibodies for neuronal NOS(nNOS),endothelial NOS(eNOS),and inducible NOS(iNOS),were visualized with protein A-gold-conjugated secondary antibodies.Stained ultrathin sections were examined and photographed with a Philips CM10 electron microscope equipped with a MEGAVIEW II camera.The specificity of the immunoreaction in all cases was assessed by omitting the primary antibodies in the labeling protocol and incubating the sections only in the protein A-gold conjugated secondary antibodies.RESULTS:Postembedding immunoelectronmicroscopy revealed the presence of nNOS,eNOS,and iNOS immunoreactivity in the myenteric neurons,the enteric smooth muscle cells,and the endothelium of capillariesrunning in the vicinity of the myenteric plexus of the rat duodenum.The cell type-specific distributions of the immunogold particles labeling the three different NOS isozymes were revealed.In the control experiments,in which the primary antiserum was omitted,virtually no postembedding gold particles were observed.CONCLUSION:This postembedding immunoelectronmicroscopic study provided the first evidence of celltype-specific differences in the subcellular distributions of NOS isoforms.展开更多
基金supported by the Natural Nature Science Foundation of China,Nos.82030071,81874004the Science and Technology Major Project of Changsha,No.kh2103008(all to JZH).
文摘Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.
基金supported by the National Natural Science Foundation of China(81372125)
文摘Objective: Highland natives adapt well to the hypoxic environment at high altitude(HA). Several genes have been reported to be linked to HA adaptation. Previous studies showed that the endothelial nitric oxide synthase(ENOS) G894 T polymorphism contributed to the physiology and pathophysiology of humans at HA by regulating the production of NO. In this meta-analysis, we evaluate the association between the ENOS G894 T polymorphism and HA adaptation through analyzing the published data. Methods: We searched all relevant literature about the ENOS G894 T polymorphism and HA adaptation in Pub Med, Medline, and Embase before Step 2015. A random-effects model was applied(Revman 5.0), and study quality was assessed in duplicate. Six studies with 634 HA native cases and 621 low-altitude controls were included in this meta-analysis. Results: From the results, we observed that the wild-type allele G was significantly overrepresented in the HA groups(OR=1.85; 95% CI, 1.47–2.33; P<0.0001). In addition, the GG genotype was significantly associated with HA adaptation(OR=1.99; 95% CI, 1.54–2.57; P<0.0001). Conclusion: Our results showed that in 894 G allele carriers, the GG genotype might be a beneficial factor for HA adaptation through enhancing the level of NO. However, more studies were needed to confirm our findings due to the limited sample size.
基金supported by grants from National Natural Sciences Foundation of China (No. 30430320 and 30770882)National 973 Project (No. 2007CB512004)
文摘3-hydroxy-3-methylgulutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies suggested that statins, besides lowering cholesterol, may protect vessels by enhancing the activity of endothelial nitric oxide synthase (eNOS). In the present study, we investigated if simvastatin increases eNOS activity through its phosphorylation in 293 cells (293-eNOS) with stable expression of eNOS. The results showed that incubation of 293-eNOS cells with simvastatin (10 μm/L) for 2 h significantly increased in the activity of eNOS as shown by the conversion of L-arginine to L-citrulline (2889.70±201.51 versus 5630.18+218.75 pmol/min . mg proteins) (P〈0.01). Western blotting revealed that simvastatin increased phosphorylation of eNOS at 1177 (ser) and also 495 (thr) but did not affect the overall expression of eNOS or inducible NOS. Further study found that simvastatin raised phosphorylation levels of Akt and AMPK, and such effect could be antagonized by Akt inhibitor or AMPK inhibitor. These results suggest that simvastatin could stimulate,the activity of eNOS via its phosphorylation by Akt and AMPK, which provides a new mechanism, other than lipid-lowering effect, for the cardiovascular protection of statins.
文摘AIM: This study was designed to examine the hypothesis that gender differences in I/R injury are associated withendothelial cell nitric oxide synthase (eNOS)-derived nitric oxide (NO).METHODS: Wistar rats were randomized into seven experimental groups (12 animals per group). Except for the sham operated groups, all rats were subjected to total liver ischemia for 40 min followed by reperfusion. All experimental groups received different treatments 45 min before the laparotomy. For each group, half of the animals (six) were used to investigate the survival; blood samples and liver tissues were obtained in the remaining six animals after 3 h of reperfusion to assess serum NO, alanine aminotransferase (ALT) and TNF-α levels, liver tissuemalondialdehyde (MDA) content, and severity of hepatic I/R injury.RESULTS: Basal serum NO levels in female sham operated (FS) group were nearly 1.5-fold of male sham operated (MS) group (66.7±11.0 μmol/L vs 45.3±10.1μmol/L, P<0.01). Although serum NO levels decreased significantly after hepatic I/R (P<0.01, vs sham operated groups), they were still significantly higher in female rat (F) group than in male rat (M) group (47.8±8.6 μmol/L vs 23.8±4.7 μmol/L, P<0.01). Serum ALT and TNF-α levels, and liver tissue MDA content were significantly lower in F group than in M group (370.5±46.4 U/L, 0.99±0.11 μg/L and 0.57±0.10 μmol/g vs668.7±78.7 U/L, 1.71±0.18 μg/Land 0.86±0.11 μmol/g, respectively, P<0.01). I/R induced significant injury to the liver both in M and F groups (P<0.01 vs sham operated groups). But the degree of hepatocyte injury was significantly milder in F group than in M group (P<0.05 and P<0.01). The median survival time was six days in F group and one day in M group. The overall survival rate was significantly higher in F group than in M group (P<0.05). When compared with male rats pretreated with saline (M group), pretreatment of male rats with 17-β- estradiol (E2) (M+E2 group) significantly increased serum NO levels and significantly decreased serum ALT and TNF-α levels, and liver tissue MDA content after I/R (P<0.01).The degree of hepatocyte injury was significantly decreased and the overall survival rate was significantly improved in M+E2 group than in M group (P<0.01 and P<0.05). TheNOS inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) treatment could completely abolish the protective effects of estrogen in both male and female rats. CONCLUSION: The protective effects afforded to female rats subjected to hepatic I/R are associated with eNOSderived NO.
文摘Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of atherosclerosis by increasing endothelial adhesiveness.Here,we sought to investigate whether CTRP1 also influences vascular dilatory functions.
基金Project (No. G50241) supported by the Start-up Fund for Study-abroad Returnee, Ministry of Education, China
文摘Objective: To investigate the relationship between the expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and angiogenesis in primary astrocytoma. Methods: Thirty-seven primary astrocytomas and 4 astrocytic hyperplasia samples were collected and divided into three groups according to histological grade. The expression of eNOS, VEGF and factor Ⅷ related antigen (FVIIIRAg) were assayed by immunohistochemistry. Microvascular density was assessed by FVIIIRAg immunoreactivity. The intensity of immunoreactivity was graded according to the percentage of positive tumor cells. Results: No eNOS and VEGF were expressed in the astrocytes and vascular endothelium in astrocytic hyperplasia.The expression of eNOS or VEGF was light in low-grade astrocytoma and strong in glioblastoma. eNOS expression in astrocytoma was very positively correlated with VEGF. eNOS and VEGF expression in anaplastic astrocytoma was median in contrast to the low grade astrocytoma and glioblastoma. Lower microvascular density was found in low grade astrocytoma than that in higher grade malignant ones. The expressions of eNOS and VEGF were correlated with microvascular density and tumor malignancy.Conclusion: This finding suggests that eNOS and VEGF may have cooperative effect in tumor angiogenesis and play an important role in the pathogenesis of primary astrocytoma.
基金Supported by the "Mecenatura" grant of Debrecen University 3/1999 to K. P., and grants from the Hungarian Ministry of Health (ETT 41/2000 to I. A., and ETT 026/2003 to F. E.) from the Hungarian Science Research Fund (OTKA 043296 to F. E.).
文摘瞄准:在煽动性的肠疾病(IBD ) 学习内皮和可诱导的氮的氧化物 synthases (eNOS 和 i NOS ) 和他们的角色的表示。方法:我们检验了重量的单位的效果一在人的脐的静脉 endothelial (HUVEC ) 的功能和生存能力上与活跃 Crohn 的疾病(CD ) 和 ulcerative (UC ) 从病人获得了。HUVEC 面对与活跃 CD 或 UC 从病人包含健康控制,或浆液的分享的浆液的媒介为 0-48 h 是有教养的。eNOS 和 i NOS 的表示被免疫荧光设想,并且由西方的污点的测密度术确定了。增长活动被 Ki-67 免疫的计算机化的图象分析估计反应房间,并且也面对 NOS 禁止者测试了, 10 (-4) mol/L L 名字。Apoptosis 和坏死被 annexin-V-biotin 方法并且由分别地染色的 propidium 碘化物检验。结果:在 HUVEC 立即在到 UC 的暴露以后,浆液 eNOS 显著地被导致,在 12 h 到达一座山峰。相反,在 eNOS 的减少与 CD 重量的单位在孵化以后被观察一 eNOS 铺平的 and 在与控制(18%+/-16% 对 23%+/-15% P【0.01 ) 相比的 20 h 是最小的。UC 或 CD 浆液与控制相比在 i NOS 引起了重要增加(UC:300%+/-21% ;CD:275%+/-27% 对 108%+/-14% , P【0.01 ) 。Apoptosis/necrosis 特征没在任何一个实验显著地不同。增加的增长活动与 L 名字面对 CD 浆液或术后疗法被检测。文化与 CD 浆液在 24 h 处理以后显示出像试管的形成。结论:IBD 重量的单位一在 eNOS/iNOS 的比率的唤起的变化,而没影响 HUVEC 的生存能力。这些同时包含了 eNOS 的下面规定和 i NOS 的起来规定,导致增加的增长活动并且可能 endothelial 的减少的反煽动性的保护。
基金the grant from the State Key Basic Research Program (No. G1998051211), the Leading Specialty Foundation of the Public Health Bu
文摘Objective: To analyze the expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) and its relation to angiogenesis. Methods: Tissue sections from 71 HCC patients were examined immunohistochemically for protein expression of iNOS, eNOS, and VEGF. Microvessal density (MVD) was counted by endothelial cells immunostained by anti-CD34 antibody. Results: Positive immunostaining for iNOS, eNOS was detected in 83.1% and 85.9% of HCC respectively. INOS and eNOS were not detected in normal hepatic tissue. MVD was 34.3±1.5/HP and 38.6±1.6/HP in HCC with positive staining for iNOS and VEGF while it was 31.2±2.8/HP, and 22.4±2.0/HP in HCC with negative staining for iNOS and VEGF (P<0.01). A correlation between NOS expression and VEGF in HCC was not observed. Conclusion: iNOS and eNOS may play a role in malignant transformation f post-hepatic cirrhosis. The expression of iNOS and VEGF favors angiogenesis of HCC.
文摘The expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of the patients with pregnancy induced hypertension (PIH) was detected and its role in the pathogenesis of PIH was studied. The pathological changes in placental vessels were observed by HE staining. NO2-/NO3- , the stable metabolic end products of NO, was measured with nitrate reductase. The eNOS activity in placental tissues was assayed by spectrophotometry. Western blot analysis was applied to detect NOSTRIN expression. The incidence of thickening and fibronoid necrosis of placental vessels was significantly higher in women with PIH than in the normal group (P〈 0.01). The levels of placental NO2-/NO3- in PIH patients (27. 53±7.48 μmol/mg) were significantly lower than in normal group (54. 27±9.53 μmol/mg, P〈0.01). The activity of eNOS was significantly decreased in PIH group (12. 826±3.61 U/mg) as compared with that in normal group (21. 72±3.83 U/mg, P〈0.01). Western blot analysis revealed that both groups expressed 58 kD NOSTRIN, but the protein level was significantly higher in women with PIH than in the normal group (P〈0.01). A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in placental tissue of women with PIH (r=-0.57, P〈0.01). It was concluded that the level of NOSTRIN expression in placenta of women with PIH was increased, which may play an important role in the pathogenesis of PIH.
文摘This study investigated the changes in human umbilical vein endothelial cells (HUVECs) induced by overexpression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) and its role in cellular injury. Recombinant NOSTRIN-expressing and empty vectors were transfected into cultured HUVECs, and factor Ⅷ-related antigen was examined by using immunohistochemical analysis. Growth curves were generated for both transfected and untransfected cells and these indicated that the prolifera- tive ability of cells overexpressing NOSTRIN was significantly decreased. The expression of NOSTRIN and eNOS proteins was detected by using Western blot analysis, endothelial NOS (eNOS) activity was assayed by using spectrophotometry, and NO2-/NO3- levels were measured usin~ nitrate reductase. Immunohistochemical analysis demonstrated that all groups expressed NOSTRIN in the plasma mem- brane and cytoplasm, and Western blot analysis confirmed that NOSTR1N levels were significantly higher in cells transfected with the NOSTR1N plasmid (P〈0.01). The activity of eNOS and the levels of NO2-/NO3 were significantly decreased in NOSTRIN overexpressing cells as compared with empty vector and untransfected cells (P〈0.01 and P〈0.01, respectively). Morphological and ultrastructural changes were observed under light and electron microscopy, and it was found that NOS- TRIN-overexpressing cells were elongated with deformities of the karyotheca, injury to the plasma membrane, increased lipids in the cytoplasm, and shortened microvilli. This study showed that overex- pression of NOSTRIN had a significant effect on eNOS activity in HUVECs and resulted in significant cellular damage.
基金Supported by Science Fund for Youths(No.81300763)
文摘AIM: To clarify how the endothelial nitric oxide synthase (eNOS, NOS3) make effect on outflow facility through the trabecular meshwork (TM). METHODS: Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC) cells were determined, still were the collagen, type IV, alpha 1 (COL4A1) and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS: The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION: Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1). Reduced NOS3 restrains the TM cell cycle progression at the G2/ M-phase transition and induced cell apoptosis.
文摘Background: Low shear stress caused by disturbed or turbulent flow at arterial branch points is known to associate with atherosclerosis. However, shear stress at the venous valve location and its association with deep vein thrombosis are less understood due to the complex and poorly understood bi-directional flow in the valve pocket region. We investigated how venous endothelial cells respond to flow shear stress around the venous valve region using a novel in vitro system that mimics venous flow. Results: Human umbilical vein EAhy. 926 cells were cultured on a flexible silastic membrane that mimicked venous tissue. Confluent cells were exposed to sinusoidal uni-and bi-directional pulsatile shear stress (0.1 to 1 dyne/cm2) for up to 6 h. Western-blot analyses indicated that endothelial nitric oxide (eNOS) expression levels decreased regardless of all tested flow patterns, stress magnitude, and shearing time. In contrast, the expression levels of inhibitor of κB (kappa B) and α (alpha)-tubulin were unaffected by the shear stress. Conclusions: Our results indicate that shear stress causes a decrease specifically in eNOS expression, suggesting that it may play a significant role in regulating inflammation related protein expression in endothelial cells.
基金supported by the National Key R&D Program of China,No.2019YFE0121200(to LQZ)the National Natural Science Foundation of China,Nos.82325017(to LQZ),82030032(to LQZ),82261138555(to DL)+2 种基金the Natural Science Foundation of Hubei Province,No.2022CFA004(to LQZ)the Natural Science Foundation of Jiangxi Province,No.20224BAB206040(to XZ)Research Project of Cognitive Science and Transdisciplinary Studies Center of Jiangxi Province,No.RZYB202201(to XZ).
文摘With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.
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 Hungarian National Grant Agency, Grant#F46201to Bagyánszki M
文摘AIM:To study the cell-type specific subcellular distribution of the three isoforms of nitric oxide synthase(NOS) in the rat duodenum.METHODS:Postembedding immunoelectronmicroscopy was performed,in which primary antibodies for neuronal NOS(nNOS),endothelial NOS(eNOS),and inducible NOS(iNOS),were visualized with protein A-gold-conjugated secondary antibodies.Stained ultrathin sections were examined and photographed with a Philips CM10 electron microscope equipped with a MEGAVIEW II camera.The specificity of the immunoreaction in all cases was assessed by omitting the primary antibodies in the labeling protocol and incubating the sections only in the protein A-gold conjugated secondary antibodies.RESULTS:Postembedding immunoelectronmicroscopy revealed the presence of nNOS,eNOS,and iNOS immunoreactivity in the myenteric neurons,the enteric smooth muscle cells,and the endothelium of capillariesrunning in the vicinity of the myenteric plexus of the rat duodenum.The cell type-specific distributions of the immunogold particles labeling the three different NOS isozymes were revealed.In the control experiments,in which the primary antiserum was omitted,virtually no postembedding gold particles were observed.CONCLUSION:This postembedding immunoelectronmicroscopic study provided the first evidence of celltype-specific differences in the subcellular distributions of NOS isoforms.