The effect of angiotensin II (ANG II) or arginine vasopressin (AVP) alone or plus atrial natriuretic peptide (ANP) on H+-ATPase subcellular vesicle trafficking was investigated in MDCK cells following intracellular pH...The effect of angiotensin II (ANG II) or arginine vasopressin (AVP) alone or plus atrial natriuretic peptide (ANP) on H+-ATPase subcellular vesicle trafficking was investigated in MDCK cells following intracellular pH (pHi) acidification by exposure to20 mMNH4Cl for 2 min in a Na+-free solution containing Schering 28080, conditions under which H+-AT-Pase is the only cell mechanism for pHi recovery. Using the acridine orange fluorescent probe (5mM) and confocal microscopy, the vesicle movement was quantified by determining, for each experimental group, the mean slope of the line indicating the changes in apical/basolateral fluorescence density ratio over time during the first 5.30 min of the pHi recovery period. Under the control conditions, the mean slope was 0.079 ± 0.0033 min-1 (14) and it increased significantly with ANG II [10-12 and 10-7 M, respectively to 0.322 ± 0.038 min-1 (13) and 0.578 ± 0.061 min-1 (12)] or AVP [10-12 and 10-6 M, respectively to 0.301 ± 0.018 min-1 (12) and 0.687 ± 0.049 min-1 (11)]. However, in presence of ANP (10-6 M, decreases cytosolic free calcium), dimethyl-BAPTA/AM (5 × 10-5 M, chelates intracellular calcium) or colchicine (10-5 M, 2-h preincubation;inhibits microtubule-dependent vesicular trafficking) alone or plus ANG II or AVP the mean slopes were similar to the control values, indicating that such agents blocked the stimulatory effect of ANG II or AVP on vesicle trafficking. The results suggest that the pathway responsible for the increase in cytosolic free calcium and the microtu-bule-dependent vesicular trafficking are involved in this hormonal stimulating effect. Whether cytosolic free calcium reduction represents an important direct mechanism for ANP impairs the dose-dependent stimulatory effect of ANG II or AVP on H+-ATPase subcellular vesicle trafficking, or is a side effect of other signaling pathways which will require additional studies.展开更多
Background Obstructive sleep apnea is a frequent medical condition consisting of repetitive sleep-related episodes of upper air ways obstruction and can lead to hypertension. Ang II type 1 receptor （AT1R） played imp...Background Obstructive sleep apnea is a frequent medical condition consisting of repetitive sleep-related episodes of upper air ways obstruction and can lead to hypertension. Ang II type 1 receptor （AT1R） played important roles in hypertension since it binds with Ang II, controlling salt-water and blood pressure homeostasis. This study explores rat aorta AT1R expression during intermittent hypoxia （IH） and the signaling pathways involved. Methods A rat model and a cell model used a BioSpherix-OxyCycler A84 system and a ProOx C21 system respectively. The arterial blood pressure was recorded by a Nihon Kohden Polygraph System. Immunohistochemic was used to focus and analyze the expression of AT1R in rat aorta. Real-time PCR and Western blotting were used to explore the signaling pathways that participated in AT1R expression. Results In this study, we found that chronic intermittent hypoxia （CIH） induced AT1R transcription which increased the blood pressure in rat aorta compared to normoxia and to sustained hypoxia. The AT1R protein expression in the aorta was similar to the real-time PCR results. We explored the signaling mechanisms involved in the AT1R induction in both rat aorta and the aortic endothelial cells by real-time PCR and Western blotting. Compared to normoxia, CIH increased ERK1 mRNA transcription but not ERK2 or p38MAPK in the aorta; whereas sustained hypoxia （SH） upregulated ERK2 but not ERK1 or p38MAPK mRNA. In cells, IH induced AT1R expression with ERK1/2 phosphorylation but reduced p38MAPKs phosphorylation, whereas SH induced only ERK1/2 phosphorylation. The ERK1/2 inhibitor PD98059 attenuated the IH- induced AT1R increase but the p38MAPK inhibitor SB203580 did not. Conclusions Our results indicate that CIH induced the elevation of rat blood pressure and aorta AT1R expression. Moreover, ATIR expression in IH and sustained hypoxia might be regulated by different signal transduction pathways, highlighting a novel regulatory function through ERK1/2 signaling in IH.展开更多
目的探讨不同剂量AngⅡ对裸鼠肝癌细胞皮下移植瘤VEGF、TGF-β1、MMP-9 m RNA表达的影响。方法建立裸鼠肝癌细胞皮下移植瘤模型32只,模型成功后随机分为Ang Ⅱ高、中、低剂量组(75、50、25μg·kg^(-1))以及对照组(生理盐水),每只...目的探讨不同剂量AngⅡ对裸鼠肝癌细胞皮下移植瘤VEGF、TGF-β1、MMP-9 m RNA表达的影响。方法建立裸鼠肝癌细胞皮下移植瘤模型32只,模型成功后随机分为Ang Ⅱ高、中、低剂量组(75、50、25μg·kg^(-1))以及对照组(生理盐水),每只裸鼠腹腔给药0.1 m L,隔日一次,连续给药21天。停药2天后,脱颈处死,检测瘤重和体积,Real-time PCR检测肿瘤组织中VEGF、TGF-β1、MMP-9的m RNA表达。结果 Ang Ⅱ高剂量组和中剂量组的瘤重和体积均显著大于对照组和低剂量组(P<0.01),Ang Ⅱ低剂量组与对照组以及高剂量组与中剂量组之间比较,差异均无统计学意义(P>0.05)。Ang Ⅱ高剂量组和中剂量组VEGF、TGF-β1、MMP-9 m RNA表达水平均高于对照组和低剂量组,差异有统计学意义(P<0.05)。高剂量组VEGF和MMP-9 m RNA表达水平显著高于中剂量组(P<0.05),但两组TGF-β1 m RNA表达水平无显著差异(P>0.05)。结论 AngⅡ可明显促进裸鼠肝癌细胞皮下移植瘤的生长和转移,可能是通过影响VEGF、TGF-β1、MMP-9的表达来发挥作用。展开更多
The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major componen...The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major component of the renin-angiotensin system (RAS). It mediates the classical biological actions of Ang II. Among the structures required for regulation and activation of the receptor, its carboxyl- terminal region plays crucial roles in receptor internalization, desensitization and phosphorylation. The mechanisms involved in heterotrimeric G-protein coupling to the receptor, activation of the downstream signaling pathway by G proteins and the Ang II signal transduction pathways leading to specific cellular responses are discussed. In addition, recent work on the identification and characterization of novel proteins associated with carboxy1-terminus of the AT1 receptor is presented. These novel proteins will advance our understanding of how the receptor is internalized and recycled as they provide molecular mechanisms for the activation and regulation of G-protein-coupled receptors.展开更多
Objective Silicosis, caused by inhalation of silica dust, is the most serious occupational disease in China and the aim of present study was to explore the protective effect of Ang(1-7) on silicotic fibrosis and myofi...Objective Silicosis, caused by inhalation of silica dust, is the most serious occupational disease in China and the aim of present study was to explore the protective effect of Ang(1-7) on silicotic fibrosis and myofibroblast differentiation induced by Ang II. Methods HOPE-MED 8050 exposure control apparatus was used to establish the rat silicosis model. Pathological changes and collagen deposition of the lung tissue were examined by H.E. and VG staining, respectively. The localizations of ACE2 and α-smooth muscle actin(α-SMA) in the lung were detected by immunohistochemistry. Expression levels of collagen type I, α-SMA, ACE2, and Mas in the lung tissue and fibroblasts were examined by western blot. Levels of ACE2, Ang(1-7), and Ang II in serum were determined by ELISA. Co-localization of ACE2 and α-SMA in fibroblasts was detected by immunofluorescence. Results Ang(1-7) induced pathological changes and enhanced collagen deposition in vivo. Ang(1-7) decreased the expressions of collagen type I and α-SMA and increased the expressions of ACE2 and Mas in the silicotic rat lung tissue and fibroblasts stimulated by Ang II. Ang(1-7) increased the levels of ACE2 and Ang(1-7) and decreased the level of Ang II in silicotic rat serum. A779 enhanced the protective effect of Ang(1-7) in fibroblasts stimulated by Ang II. Conclusion Ang(1-7) exerted protective effect on silicotic fibrosis and myofibroblast differentiation induced by Ang II by regulating ACE2-Ang(1-7)-Mas axis.展开更多
目的:探讨不同中医治法对高尿酸血症模型大鼠血清AngⅠ,AngⅡ水平的影响。方法:将Wi st ar大鼠135只随机分为空白对照组、模型组、西药治疗组与中药复方(滋肾阴、温肾阳、健脾、活血、化痰及利湿组,每组15只)6个治疗组,除空白对照组外,...目的:探讨不同中医治法对高尿酸血症模型大鼠血清AngⅠ,AngⅡ水平的影响。方法:将Wi st ar大鼠135只随机分为空白对照组、模型组、西药治疗组与中药复方(滋肾阴、温肾阳、健脾、活血、化痰及利湿组,每组15只)6个治疗组,除空白对照组外,其余各组采用腺嘌呤联合乙胺丁醇法建立大鼠高尿酸血症动物模型,造模第21天开始给予各治疗组相应治疗,连续2周。检测血清AngⅠ,AngⅡ水平,观察其变化情况。结果:与模型组比较,除西药治疗组与活血组、利湿组和化痰组血清AngⅠ水平降低外其余治疗组血清AngⅠ水平变化不明显,无显著性差异(P>0.05);西药治疗组与治疗组中的活血组、利湿组和化痰组血清AngⅡ水平明显下降,有显著性差异(P<0.05)。结论:活血、利湿和化痰治法有降低血清AngⅠ水平的趋势;不同中医治法均可降低血清AngⅡ水平,其中以活血、利湿、化痰法治疗效果明显,对高尿酸血症具有治疗作用。展开更多
文摘The effect of angiotensin II (ANG II) or arginine vasopressin (AVP) alone or plus atrial natriuretic peptide (ANP) on H+-ATPase subcellular vesicle trafficking was investigated in MDCK cells following intracellular pH (pHi) acidification by exposure to20 mMNH4Cl for 2 min in a Na+-free solution containing Schering 28080, conditions under which H+-AT-Pase is the only cell mechanism for pHi recovery. Using the acridine orange fluorescent probe (5mM) and confocal microscopy, the vesicle movement was quantified by determining, for each experimental group, the mean slope of the line indicating the changes in apical/basolateral fluorescence density ratio over time during the first 5.30 min of the pHi recovery period. Under the control conditions, the mean slope was 0.079 ± 0.0033 min-1 (14) and it increased significantly with ANG II [10-12 and 10-7 M, respectively to 0.322 ± 0.038 min-1 (13) and 0.578 ± 0.061 min-1 (12)] or AVP [10-12 and 10-6 M, respectively to 0.301 ± 0.018 min-1 (12) and 0.687 ± 0.049 min-1 (11)]. However, in presence of ANP (10-6 M, decreases cytosolic free calcium), dimethyl-BAPTA/AM (5 × 10-5 M, chelates intracellular calcium) or colchicine (10-5 M, 2-h preincubation;inhibits microtubule-dependent vesicular trafficking) alone or plus ANG II or AVP the mean slopes were similar to the control values, indicating that such agents blocked the stimulatory effect of ANG II or AVP on vesicle trafficking. The results suggest that the pathway responsible for the increase in cytosolic free calcium and the microtu-bule-dependent vesicular trafficking are involved in this hormonal stimulating effect. Whether cytosolic free calcium reduction represents an important direct mechanism for ANP impairs the dose-dependent stimulatory effect of ANG II or AVP on H+-ATPase subcellular vesicle trafficking, or is a side effect of other signaling pathways which will require additional studies.
基金The research was supported by a grant from the National Natural Science Foundation of China （No. 81070067）. The authors decleard no conflict of interest.
文摘Background Obstructive sleep apnea is a frequent medical condition consisting of repetitive sleep-related episodes of upper air ways obstruction and can lead to hypertension. Ang II type 1 receptor （AT1R） played important roles in hypertension since it binds with Ang II, controlling salt-water and blood pressure homeostasis. This study explores rat aorta AT1R expression during intermittent hypoxia （IH） and the signaling pathways involved. Methods A rat model and a cell model used a BioSpherix-OxyCycler A84 system and a ProOx C21 system respectively. The arterial blood pressure was recorded by a Nihon Kohden Polygraph System. Immunohistochemic was used to focus and analyze the expression of AT1R in rat aorta. Real-time PCR and Western blotting were used to explore the signaling pathways that participated in AT1R expression. Results In this study, we found that chronic intermittent hypoxia （CIH） induced AT1R transcription which increased the blood pressure in rat aorta compared to normoxia and to sustained hypoxia. The AT1R protein expression in the aorta was similar to the real-time PCR results. We explored the signaling mechanisms involved in the AT1R induction in both rat aorta and the aortic endothelial cells by real-time PCR and Western blotting. Compared to normoxia, CIH increased ERK1 mRNA transcription but not ERK2 or p38MAPK in the aorta; whereas sustained hypoxia （SH） upregulated ERK2 but not ERK1 or p38MAPK mRNA. In cells, IH induced AT1R expression with ERK1/2 phosphorylation but reduced p38MAPKs phosphorylation, whereas SH induced only ERK1/2 phosphorylation. The ERK1/2 inhibitor PD98059 attenuated the IH- induced AT1R increase but the p38MAPK inhibitor SB203580 did not. Conclusions Our results indicate that CIH induced the elevation of rat blood pressure and aorta AT1R expression. Moreover, ATIR expression in IH and sustained hypoxia might be regulated by different signal transduction pathways, highlighting a novel regulatory function through ERK1/2 signaling in IH.
文摘目的探讨不同剂量AngⅡ对裸鼠肝癌细胞皮下移植瘤VEGF、TGF-β1、MMP-9 m RNA表达的影响。方法建立裸鼠肝癌细胞皮下移植瘤模型32只,模型成功后随机分为Ang Ⅱ高、中、低剂量组(75、50、25μg·kg^(-1))以及对照组(生理盐水),每只裸鼠腹腔给药0.1 m L,隔日一次,连续给药21天。停药2天后,脱颈处死,检测瘤重和体积,Real-time PCR检测肿瘤组织中VEGF、TGF-β1、MMP-9的m RNA表达。结果 Ang Ⅱ高剂量组和中剂量组的瘤重和体积均显著大于对照组和低剂量组(P<0.01),Ang Ⅱ低剂量组与对照组以及高剂量组与中剂量组之间比较,差异均无统计学意义(P>0.05)。Ang Ⅱ高剂量组和中剂量组VEGF、TGF-β1、MMP-9 m RNA表达水平均高于对照组和低剂量组,差异有统计学意义(P<0.05)。高剂量组VEGF和MMP-9 m RNA表达水平显著高于中剂量组(P<0.05),但两组TGF-β1 m RNA表达水平无显著差异(P>0.05)。结论 AngⅡ可明显促进裸鼠肝癌细胞皮下移植瘤的生长和转移,可能是通过影响VEGF、TGF-β1、MMP-9的表达来发挥作用。
文摘The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major component of the renin-angiotensin system (RAS). It mediates the classical biological actions of Ang II. Among the structures required for regulation and activation of the receptor, its carboxyl- terminal region plays crucial roles in receptor internalization, desensitization and phosphorylation. The mechanisms involved in heterotrimeric G-protein coupling to the receptor, activation of the downstream signaling pathway by G proteins and the Ang II signal transduction pathways leading to specific cellular responses are discussed. In addition, recent work on the identification and characterization of novel proteins associated with carboxy1-terminus of the AT1 receptor is presented. These novel proteins will advance our understanding of how the receptor is internalized and recycled as they provide molecular mechanisms for the activation and regulation of G-protein-coupled receptors.
基金supported by the National Natural Science Foundation of China [grant no.81472953]Natural Science Foundation of Hebei Province [grant no.H2016209170]+2 种基金Graduate Student Innovation Fund of Hebei Province [grant no.2016196]Graduate Student Innovation Fund of North China University of Science and Technology [grant no.2016B10]undergraduate innovative project of North China University of Science and Technology [grant no.X2017354]
文摘Objective Silicosis, caused by inhalation of silica dust, is the most serious occupational disease in China and the aim of present study was to explore the protective effect of Ang(1-7) on silicotic fibrosis and myofibroblast differentiation induced by Ang II. Methods HOPE-MED 8050 exposure control apparatus was used to establish the rat silicosis model. Pathological changes and collagen deposition of the lung tissue were examined by H.E. and VG staining, respectively. The localizations of ACE2 and α-smooth muscle actin(α-SMA) in the lung were detected by immunohistochemistry. Expression levels of collagen type I, α-SMA, ACE2, and Mas in the lung tissue and fibroblasts were examined by western blot. Levels of ACE2, Ang(1-7), and Ang II in serum were determined by ELISA. Co-localization of ACE2 and α-SMA in fibroblasts was detected by immunofluorescence. Results Ang(1-7) induced pathological changes and enhanced collagen deposition in vivo. Ang(1-7) decreased the expressions of collagen type I and α-SMA and increased the expressions of ACE2 and Mas in the silicotic rat lung tissue and fibroblasts stimulated by Ang II. Ang(1-7) increased the levels of ACE2 and Ang(1-7) and decreased the level of Ang II in silicotic rat serum. A779 enhanced the protective effect of Ang(1-7) in fibroblasts stimulated by Ang II. Conclusion Ang(1-7) exerted protective effect on silicotic fibrosis and myofibroblast differentiation induced by Ang II by regulating ACE2-Ang(1-7)-Mas axis.
文摘目的:探讨不同中医治法对高尿酸血症模型大鼠血清AngⅠ,AngⅡ水平的影响。方法:将Wi st ar大鼠135只随机分为空白对照组、模型组、西药治疗组与中药复方(滋肾阴、温肾阳、健脾、活血、化痰及利湿组,每组15只)6个治疗组,除空白对照组外,其余各组采用腺嘌呤联合乙胺丁醇法建立大鼠高尿酸血症动物模型,造模第21天开始给予各治疗组相应治疗,连续2周。检测血清AngⅠ,AngⅡ水平,观察其变化情况。结果:与模型组比较,除西药治疗组与活血组、利湿组和化痰组血清AngⅠ水平降低外其余治疗组血清AngⅠ水平变化不明显,无显著性差异(P>0.05);西药治疗组与治疗组中的活血组、利湿组和化痰组血清AngⅡ水平明显下降,有显著性差异(P<0.05)。结论:活血、利湿和化痰治法有降低血清AngⅠ水平的趋势;不同中医治法均可降低血清AngⅡ水平,其中以活血、利湿、化痰法治疗效果明显,对高尿酸血症具有治疗作用。
