Objective To investigate the mechanism of a novel angiotensin Ⅱ type 1 receptor-associated protein （ATRAP） interfering with angiotensin Ⅱ type 1 （AT1） receptor-mediated vascular smooth muscle cell （VSMC） growt...Objective To investigate the mechanism of a novel angiotensin Ⅱ type 1 receptor-associated protein （ATRAP） interfering with angiotensin Ⅱ type 1 （AT1） receptor-mediated vascular smooth muscle cell （VSMC） growth and neointimal formation. Methods VSMCs isolated from thoracic aorta of adult Sprague-Dawley （SD） rats were used in this study. ATRAP cDNA was subcloned into pcDNA3 vector and then transfected into VSMCs. DNA synthesis and extracellular signal-regulated kinase （ERK） and phospho-ERK expressions in VSMCs were assayed by measurement of ^3H thymidine incorporation and Western blotting, respectively. Morphological changes were observed in the balloon injured artery with or without transfection of ATRAP cDNA using 12-week-old male SD rats. Results ATRAP overexpression in VSMCs inhibited angiotensin Ⅱ （Ang Ⅱ）-induced ^3H thymidine incorporation 48 hours after Ang Ⅱ stimulation （ P 〈 0. 05 ）. In VSMC, Ang Ⅱ stimulation increased the phosphorylation of ERK, which reached the peak around 60 minutes. The activation of phospho-ERK was significantly decreased by ATRAP （ P 〈 0. 05 ）. Neointimal formation was markedly inhibited by ATRAP overexpression in injuried arteries.Conclusions The AT1 receptor-derived activation of ERK plays an essential role in Ang Ⅱ-induced VSMC growth. The growth inhibitory effects of ATRAP might be due to interfering with AT1 receptor-mediated activation of ERK in VSMC growth and neointimal formation.展开更多
Background In type 2 diabetes mellitus （T2DM）, high-density lipoprotein （HDL） impairs its anti-atherogenic properties and even develops to a pro-inflammatory and pro-atherogenic phenotype because of abnormal compo...Background In type 2 diabetes mellitus （T2DM）, high-density lipoprotein （HDL） impairs its anti-atherogenic properties and even develops to a pro-inflammatory and pro-atherogenic phenotype because of abnormal compositions and modifications. In this study, we ex- amined the effects and the related mechanisms of glycation of HDL on the proliferation and migration of vascular smooth muscle cells （VSMCs）. Methods ＆ Results Glycated HDL （G-HDL） was modified with D-glucose （25 mmol/L） in vitro. Diabetic HDL （D-HDL） was isolated from T2DM patients. Rat VSMCs were isolated from the thoracic aortas. Human VSMCs were obtained from ScienCell Research Laboratories. Alpha-actin was detected through immunofiuorescence. VSMC proliferation was assayed by Cell Count. VSMC migration was determined by transwell chamber and scratch-wound assay. Intracellular reactive oxygen species （ROS） was detected based on ROS-medi- ated 2＇,7＇-dichlorofluorescein （DCFH-DA） fluorescence. Compared to native HDL （N-HDL）, G-HDL remarkably promoted VSMC prolif- eration and migration in the dose and time-dependent manners. In addition, G-HDL enhanced ROS generation in VSMCs. However, the ROS scavenger, N-acetylcysteine, efficiently decreased ROS production and subsequently inhibited the proliferation of VSMCs induced by G-HDL. Similarly, D-HDL from T2DM patients also promoted ROS release and VSMC proliferation and migration. Conclusions HDL either glycated in vitro or isolated from T2DM patients triggered VSMC proliferation, migration, and oxidative stress. These results might partly interpret the higher morbidity of cardiovascular disease in T2DM patients.展开更多
Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabb...Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase （MD） activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 （100ug/L） increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL（501xg/ml） elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group （P〈0.01 ）. Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.展开更多
文摘Objective To investigate the mechanism of a novel angiotensin Ⅱ type 1 receptor-associated protein （ATRAP） interfering with angiotensin Ⅱ type 1 （AT1） receptor-mediated vascular smooth muscle cell （VSMC） growth and neointimal formation. Methods VSMCs isolated from thoracic aorta of adult Sprague-Dawley （SD） rats were used in this study. ATRAP cDNA was subcloned into pcDNA3 vector and then transfected into VSMCs. DNA synthesis and extracellular signal-regulated kinase （ERK） and phospho-ERK expressions in VSMCs were assayed by measurement of ^3H thymidine incorporation and Western blotting, respectively. Morphological changes were observed in the balloon injured artery with or without transfection of ATRAP cDNA using 12-week-old male SD rats. Results ATRAP overexpression in VSMCs inhibited angiotensin Ⅱ （Ang Ⅱ）-induced ^3H thymidine incorporation 48 hours after Ang Ⅱ stimulation （ P 〈 0. 05 ）. In VSMC, Ang Ⅱ stimulation increased the phosphorylation of ERK, which reached the peak around 60 minutes. The activation of phospho-ERK was significantly decreased by ATRAP （ P 〈 0. 05 ）. Neointimal formation was markedly inhibited by ATRAP overexpression in injuried arteries.Conclusions The AT1 receptor-derived activation of ERK plays an essential role in Ang Ⅱ-induced VSMC growth. The growth inhibitory effects of ATRAP might be due to interfering with AT1 receptor-mediated activation of ERK in VSMC growth and neointimal formation.
基金This project was supported by Grant 31200884 from the National Natural Science Foundation of China Grant 2016D016, 2016-ZQN-92, and 2016-2-75 from the Natural Science Foundation of Fujian and Grant 3502Z20154048, 3502Z20144061, and 3502Z20154047 from the Natural Scien- ce Foundation of Xiamen.
文摘Background In type 2 diabetes mellitus （T2DM）, high-density lipoprotein （HDL） impairs its anti-atherogenic properties and even develops to a pro-inflammatory and pro-atherogenic phenotype because of abnormal compositions and modifications. In this study, we ex- amined the effects and the related mechanisms of glycation of HDL on the proliferation and migration of vascular smooth muscle cells （VSMCs）. Methods ＆ Results Glycated HDL （G-HDL） was modified with D-glucose （25 mmol/L） in vitro. Diabetic HDL （D-HDL） was isolated from T2DM patients. Rat VSMCs were isolated from the thoracic aortas. Human VSMCs were obtained from ScienCell Research Laboratories. Alpha-actin was detected through immunofiuorescence. VSMC proliferation was assayed by Cell Count. VSMC migration was determined by transwell chamber and scratch-wound assay. Intracellular reactive oxygen species （ROS） was detected based on ROS-medi- ated 2＇,7＇-dichlorofluorescein （DCFH-DA） fluorescence. Compared to native HDL （N-HDL）, G-HDL remarkably promoted VSMC prolif- eration and migration in the dose and time-dependent manners. In addition, G-HDL enhanced ROS generation in VSMCs. However, the ROS scavenger, N-acetylcysteine, efficiently decreased ROS production and subsequently inhibited the proliferation of VSMCs induced by G-HDL. Similarly, D-HDL from T2DM patients also promoted ROS release and VSMC proliferation and migration. Conclusions HDL either glycated in vitro or isolated from T2DM patients triggered VSMC proliferation, migration, and oxidative stress. These results might partly interpret the higher morbidity of cardiovascular disease in T2DM patients.
文摘Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase （MD） activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 （100ug/L） increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL（501xg/ml） elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group （P〈0.01 ）. Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.
