AIM:To analyze the change of dimethylarginine plasma levels in cirrhotic patients receiving transjugular intrahepatic portosystemic shunt(TIPS).METHODS:To determine arginine,asymmetric dimethylarginine(ADMA),symmetric...AIM:To analyze the change of dimethylarginine plasma levels in cirrhotic patients receiving transjugular intrahepatic portosystemic shunt(TIPS).METHODS:To determine arginine,asymmetric dimethylarginine(ADMA),symmetric dimethylarginine(SDMA),and nitric oxide(NO) plasma levels,blood samples were collected from the superior cava,hepatic,and portal vein just before,directly after,and 3 mo after TIPS-placement.RESULTS:A significant increase in the arginine/ADMA ratio after TIPS placement was shown.Moreover,TIPS placement enhanced renal function and thereby decreased systemic SDMA levels.In patients with renal dysfunction before TIPS placement,both the arginine/ADMA ratio and creatinine clearance rate increased significantly,while this was not the case in patients with normal renal function before TIPS placement.Hepatic function did not change significantly after TIPS placement and no significant decline in ADMA plasma levels was measured.CONCLUSION:The increase of the arginine/ADMA ratio after TIPS placement suggests an increase in intracellular NO bioavailability.In addition,this study suggests that TIPS placement does not alter dimethylarginine dimethylaminohydrolase(DDAH) activity and confirms the major role of the liver as an ADMA clearing organ.展开更多
Herein, we present a novel method of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) determination within biological samples using protein precipitation and LC/MS/MS. Chromatographic separatio...Herein, we present a novel method of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) determination within biological samples using protein precipitation and LC/MS/MS. Chromatographic separation of ADMA and SDMA was successfully performed using a silica column with optimized elution, or mobile phase, of 10 mM ammonium acetate buffer H2O/methanol/acetonitrile (20/30/45, v/v) at pH 4. The calibration ranges were 0.50 – 50.0 μg●mL-1, and good linearities were obtained for all compounds ( γ > 0.99). The intra- and inter-assay accuracies with recoveries and precisions at three concentration levels (i.e. 1.00, 5.00 and 25.0 μg●mL-1) were better than 86.9% and 7.36%, respectively. The analytical performance of the method was evaluated by determination of compounds in plasma, urine and tissues from male BALBc/J mice. For the first time, we were able to characterize the distribution of ADMA, SDMA and ADMA/SDMA in plasma, urine, brain, heart, kidneys, liver, lungs, pancreas and spleen. Additionally, we demonstrated that the ADMA/SDMA ratio in the brain was approximately 10-fold lower than all the other biological samples. Only 10 μL of plasma, 1 μL of urine and about 25 mg of tissues were required. These results suggest that the developed methodology was useful in ADMA and SDMA determination within biological samples.展开更多
Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PR...Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.展开更多
Background: Preeclampsia is a worldwide pregnancy complication, and early identification of patients with an increased risk is one of the key goals in obstetrics. First trimester screening is crucial over the second t...Background: Preeclampsia is a worldwide pregnancy complication, and early identification of patients with an increased risk is one of the key goals in obstetrics. First trimester screening is crucial over the second trimester for understanding the early onset of the disorder, with basal levels of the biochemical parameters associated with the underlying placentation process. Objective: The study aims to assess the levels of serum biochemical markers in pregnant women at first trimester, to evaluate statistical significance and correlation of the values in support of trophoblastic cell integrity, endothelial function and oxidative stress. Materials and Methods: A longitudinal study was conducted on 86 pregnant women of age group 20 - 35 years, Primigravida with singleton pregnancy who visited prenatal check up between 11 - 13 weeks of gestation. Maternal sera was collected for screening Placental protein 13 (PP13), Caspase 3, Asymmetric dimethylarginine (ADMA), Nitric oxide (NO) by ELISA. Xanthine oxidase (XO) activity was assayed spectrophotometrically. Calcium and Uric acid (UA) were measured by dry chemistry analyser. Results: The mean ± SD values for mean arterial pressure (MAP) are 108.4 ± 18.9, UA 2.01 ± 0.85, Total oxidant status (TOS) 12.83 ± 5.17, Total antioxidant capacity (TAC) 24.10 ± 14.28, XO 1.01 ± 2.67, Caspase-3 1.76 ± 2.22, PP13 489.77 ± 53.6, Calcium 10.88 ± 1.97, ADMA 19.03 ± 17.08 and NO 1.16 ± 0.75. The statistical analysis by SPSS package version 20 revealed positive correlation between ADMA & Caspase-3 (r = +0.435), PP13 & NO (r = +0.241), TOS & TAC (r = +0.176), UA & ADMA (r = +0.176), UA & TAC (r = +0.168) and negative correlation between PP13 & ADMA (r = -0.158), NO & TOS (r = -0.114), UA & XO (r = -0.173), UA & NO (r = -0.186), UA & Caspase 3 (r = -0.106) and MAP & Calcium (r = -0.303). Conclusion: The study concludes that first trimester biochemical markers and their correlation predict the trophoblastic cell integrity and endothelial function during placentation under prevailing oxidative stress conditions, which may help in identifying women who subsequently go on to develop preeclampsia.展开更多
Cardiac Allograft Vasculopathy, an accelerated form of arterial occlusive disease, is the major cause of death in the long-term after heart transplantation. Multiple factors influence the initiation and progression of...Cardiac Allograft Vasculopathy, an accelerated form of arterial occlusive disease, is the major cause of death in the long-term after heart transplantation. Multiple factors influence the initiation and progression of CAV. These include ischemia-reperfusion, dyslipidemia, insulin resistance, and hypertension due to the use of immunosuppressive agents, the direct effects of immunosuppressive agents on endothelial function, and viruses (CMV). Impaired endothelial function reflects abnormalities in the production or activity of several vasoactive substances. Disruption of the nitric oxide synthase (NOS) pathway leads to changes in vascular reactivity, structure, and interaction with circulating blood components. Since endothelium-derived nitric oxide (NO) suppresses vascular cell proliferation and vascular inflammation, a deficit in vascular NO facilitates development of CAV. The link between oxidative stress and CAV largely exists in the balance between free radical superoxide generation and NO production. This review focuses on identifying the oxidative stress factors affecting CAV.展开更多
Background and Objectives: Exhaled nitric oxide (NO) is decreased by smoking while oxides of nitrogen such as nitrites/nitrates (NOx) are increased. It was hypothesised that in vitro cigarette smoke extract (CSE) woul...Background and Objectives: Exhaled nitric oxide (NO) is decreased by smoking while oxides of nitrogen such as nitrites/nitrates (NOx) are increased. It was hypothesised that in vitro cigarette smoke extract (CSE) would either inhibit NO generation by increasing the NO synthase inhibitor, NG, NG-dimethyl-L-arginine (ADMA) or increase NOx levels via an oxidation pathway, which in turn could be inhibited by the antioxidant N-acetylcysteine NAC. Methods: Transformed airway cells (A549) were cultured with control medium, 1.0% CSE in culture medium, or 0.8 mM NAC with 1.0% CSE. Baseline L-arginine, NOx and ADMA levels were measured in the media. Conditioned media were then sampled at 1hour, 6 hours, 24 hours, 48 hours and 72 hours after incubation. Results: CSE induced significantly higher NOx levels (mean (SD) peak increase of 135.8 (126.6)% after incubation for 6 hours (p x which was partially reversed by NAC pre-treatment. ADMA levels were also increased after CSE exposure, suggesting that it activates the NO pathway via oxidative-stress while inhibition probably occurs via both ADMA and NOS.展开更多
文摘AIM:To analyze the change of dimethylarginine plasma levels in cirrhotic patients receiving transjugular intrahepatic portosystemic shunt(TIPS).METHODS:To determine arginine,asymmetric dimethylarginine(ADMA),symmetric dimethylarginine(SDMA),and nitric oxide(NO) plasma levels,blood samples were collected from the superior cava,hepatic,and portal vein just before,directly after,and 3 mo after TIPS-placement.RESULTS:A significant increase in the arginine/ADMA ratio after TIPS placement was shown.Moreover,TIPS placement enhanced renal function and thereby decreased systemic SDMA levels.In patients with renal dysfunction before TIPS placement,both the arginine/ADMA ratio and creatinine clearance rate increased significantly,while this was not the case in patients with normal renal function before TIPS placement.Hepatic function did not change significantly after TIPS placement and no significant decline in ADMA plasma levels was measured.CONCLUSION:The increase of the arginine/ADMA ratio after TIPS placement suggests an increase in intracellular NO bioavailability.In addition,this study suggests that TIPS placement does not alter dimethylarginine dimethylaminohydrolase(DDAH) activity and confirms the major role of the liver as an ADMA clearing organ.
文摘Herein, we present a novel method of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) determination within biological samples using protein precipitation and LC/MS/MS. Chromatographic separation of ADMA and SDMA was successfully performed using a silica column with optimized elution, or mobile phase, of 10 mM ammonium acetate buffer H2O/methanol/acetonitrile (20/30/45, v/v) at pH 4. The calibration ranges were 0.50 – 50.0 μg●mL-1, and good linearities were obtained for all compounds ( γ > 0.99). The intra- and inter-assay accuracies with recoveries and precisions at three concentration levels (i.e. 1.00, 5.00 and 25.0 μg●mL-1) were better than 86.9% and 7.36%, respectively. The analytical performance of the method was evaluated by determination of compounds in plasma, urine and tissues from male BALBc/J mice. For the first time, we were able to characterize the distribution of ADMA, SDMA and ADMA/SDMA in plasma, urine, brain, heart, kidneys, liver, lungs, pancreas and spleen. Additionally, we demonstrated that the ADMA/SDMA ratio in the brain was approximately 10-fold lower than all the other biological samples. Only 10 μL of plasma, 1 μL of urine and about 25 mg of tissues were required. These results suggest that the developed methodology was useful in ADMA and SDMA determination within biological samples.
基金Supported by National Natural Science Foundation of China(30825023)
文摘Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.
文摘Background: Preeclampsia is a worldwide pregnancy complication, and early identification of patients with an increased risk is one of the key goals in obstetrics. First trimester screening is crucial over the second trimester for understanding the early onset of the disorder, with basal levels of the biochemical parameters associated with the underlying placentation process. Objective: The study aims to assess the levels of serum biochemical markers in pregnant women at first trimester, to evaluate statistical significance and correlation of the values in support of trophoblastic cell integrity, endothelial function and oxidative stress. Materials and Methods: A longitudinal study was conducted on 86 pregnant women of age group 20 - 35 years, Primigravida with singleton pregnancy who visited prenatal check up between 11 - 13 weeks of gestation. Maternal sera was collected for screening Placental protein 13 (PP13), Caspase 3, Asymmetric dimethylarginine (ADMA), Nitric oxide (NO) by ELISA. Xanthine oxidase (XO) activity was assayed spectrophotometrically. Calcium and Uric acid (UA) were measured by dry chemistry analyser. Results: The mean ± SD values for mean arterial pressure (MAP) are 108.4 ± 18.9, UA 2.01 ± 0.85, Total oxidant status (TOS) 12.83 ± 5.17, Total antioxidant capacity (TAC) 24.10 ± 14.28, XO 1.01 ± 2.67, Caspase-3 1.76 ± 2.22, PP13 489.77 ± 53.6, Calcium 10.88 ± 1.97, ADMA 19.03 ± 17.08 and NO 1.16 ± 0.75. The statistical analysis by SPSS package version 20 revealed positive correlation between ADMA & Caspase-3 (r = +0.435), PP13 & NO (r = +0.241), TOS & TAC (r = +0.176), UA & ADMA (r = +0.176), UA & TAC (r = +0.168) and negative correlation between PP13 & ADMA (r = -0.158), NO & TOS (r = -0.114), UA & XO (r = -0.173), UA & NO (r = -0.186), UA & Caspase 3 (r = -0.106) and MAP & Calcium (r = -0.303). Conclusion: The study concludes that first trimester biochemical markers and their correlation predict the trophoblastic cell integrity and endothelial function during placentation under prevailing oxidative stress conditions, which may help in identifying women who subsequently go on to develop preeclampsia.
文摘Cardiac Allograft Vasculopathy, an accelerated form of arterial occlusive disease, is the major cause of death in the long-term after heart transplantation. Multiple factors influence the initiation and progression of CAV. These include ischemia-reperfusion, dyslipidemia, insulin resistance, and hypertension due to the use of immunosuppressive agents, the direct effects of immunosuppressive agents on endothelial function, and viruses (CMV). Impaired endothelial function reflects abnormalities in the production or activity of several vasoactive substances. Disruption of the nitric oxide synthase (NOS) pathway leads to changes in vascular reactivity, structure, and interaction with circulating blood components. Since endothelium-derived nitric oxide (NO) suppresses vascular cell proliferation and vascular inflammation, a deficit in vascular NO facilitates development of CAV. The link between oxidative stress and CAV largely exists in the balance between free radical superoxide generation and NO production. This review focuses on identifying the oxidative stress factors affecting CAV.
文摘Background and Objectives: Exhaled nitric oxide (NO) is decreased by smoking while oxides of nitrogen such as nitrites/nitrates (NOx) are increased. It was hypothesised that in vitro cigarette smoke extract (CSE) would either inhibit NO generation by increasing the NO synthase inhibitor, NG, NG-dimethyl-L-arginine (ADMA) or increase NOx levels via an oxidation pathway, which in turn could be inhibited by the antioxidant N-acetylcysteine NAC. Methods: Transformed airway cells (A549) were cultured with control medium, 1.0% CSE in culture medium, or 0.8 mM NAC with 1.0% CSE. Baseline L-arginine, NOx and ADMA levels were measured in the media. Conditioned media were then sampled at 1hour, 6 hours, 24 hours, 48 hours and 72 hours after incubation. Results: CSE induced significantly higher NOx levels (mean (SD) peak increase of 135.8 (126.6)% after incubation for 6 hours (p x which was partially reversed by NAC pre-treatment. ADMA levels were also increased after CSE exposure, suggesting that it activates the NO pathway via oxidative-stress while inhibition probably occurs via both ADMA and NOS.
