摘要:目的: 探讨激活转录因子(ATF1)在血管紧张素Ⅱ(AngⅡ)诱导血管平滑肌细胞(VSMCs)中NOX1基因表达增加的作用。 方法 :体外培养大鼠主动脉VSMCs,用荧光实时定量逆转录PCR(Realtime RTPCR)检测NOX1基因表达的量,Western Blot检测ATF1蛋白在AngⅡ的刺激是否引起NOX1基因的高表达并用RNA干扰(RNAi)技术转染VSMCs使ATF1基因沉默来观察NOX1的表达。 结果 :AngⅡ能够诱导 NOX1基因的表达增加以及增强ATF1的磷酸化及活性,ATF1基因沉默反过来可抑制AngⅡ诱导的NOX1基因表达的增加。 结论 :在大鼠的VSMCs中,ATF1是介导NOX1基因表达的一个必须的转录因子。Abstract: Objective: To detect the role of activating transcription factor (ATF1) involved in angiotensinⅡ(AngⅡ) stimulated NOX1 gene expression.Methods :Rat aortic vascellum smooth muscle cells(VSMCs) were cultured in vitro.Use Realtime RTPCR to measure the expression of NOX1 gene.Western Blot Analysis was carried out to test the activity of ATF1 protein. RNA interference was used and transfected into VSMCs to knockdown ATF1 gene expression, and then measured NOX1 gene expression.Results : AngⅡ stimulated NOX1 gene expression and phosphorylation of ATF1 Gene silencing of ATF1 attenuated the upregulation of NOX1 mRNA by AngⅡ. Conclusion :ATF1 is an essential transcription factor that mediates expression of NOX1 gene in VSMCs by AngⅡ.
To investigate the mechanisms of splanchnic hyperdynamics in portal hypertension (PHT), angiotensin Ⅱ(A-Ⅱ) receptor maximal binding capacity (Bmax) and dissociation constants (Kd) of splanchnic blood vessels in rats with prehepatic PHT were studied by radioligand binding analysis. The results showed that the A-Ⅱ receptor Bmax in the superior mesenteric artery and portal vein of PHT animals (206.9±39.3 fmol/mg protein and 31.5±9.2 fmol/mg protein respectively) was all significantly lower than that of the controls (297.2±44.7 fmol/mg protein and 53.4±12.1 fmol/mg protein respectively, Ｐ＜0.01). The A-Ⅱ receptor Kd in the superior mesenteric artery was markedly increased in PHT animals (1.03±0.11 nmol/L) compared with that in controls (0.88±0.08 nmol/L, Ｐ＜0.05). In the portal vein, the A-Ⅱ receptor Kd in PHT animals was slightly higher than in controls, but no significant difference was observed between the two groups. These results suggest that the vascular hyporesponsiveness to A-Ⅱ in PHT is caused partially by a reduction in number and a decrease in affinity of vascular A-Ⅱ receptors, and these changes may possibly lead to the formation of hyperdynamic circulation.
摘要:目的: 探讨在血管紧张素Ⅱ(AngⅡ)诱导血管平滑肌细胞(VSMCs)NOX1基因表达增加中线粒体所起的作用。 方法 :体外培养大鼠主动脉VSMCs,用线粒体呼吸链的抑制剂阻断线粒体的作用,用荧光实时定量PCR检测NOX1基因表达的量。 结果 :AngⅡ能够诱导 NOX1基因的表达增加,线粒体呼吸链的抑制剂能够抑制上述这一作用。 结论 :在大鼠的VSMCs中,AngⅡ诱导NOX1的增加通过线粒体呼吸的作用。Abstract: Objective: To detect the role of mitochondria involved in Angiotensin Ⅱ(Ang Ⅱ) induced NOX1 gene expression. Methods :Rat aortic vascellum smooth muscle cells(VSMCs) were cultured in vitro,and were treated with or without some inhibitors of complexs in mitochondrial respiratory chain. Realtime RTPCR was used to calculate the expression of NOX1 mRNA. Results :AngⅡ stimulated NOX1 gene expression,while some inhibitors of complexs in mitochondrial respiratory chain attenuated this progress.〖WTHZ〗Conclusion : Mitochondrial respiratory chain mediates expression of NOX1 gene in VSMCs by AngⅡ.
Objective To observe the effect of angiotensin Ⅱ (Ang Ⅱ) or/and transforming growth factor β(TGF-β) on human skin fibroblast proliferation, and to explore the possible signaling mechanism involved in their actions. Methods Cultured human skin fibroblasts were treated with different concentrations of Ang Ⅱ (1×10-10 , 1×10-9，1×10-8 and 1×10-7 mol/L) , TGF-β(0.1, 1.0 and 10.0 ng/ml), and 1×10 -10 mol/L Ang Ⅱ＋0.1 ng/ml TGF-β, respectively. The cell proliferation was determined by3Hthymidine (3H-TdR) incorporation. The phosphorylation of extracellular signalregulated kinases (ERK) was detected by Western blot. Results Ang Ⅱ at 1×10-9，1×10-8，1× 10-7 mol/L or TGF-β at 1.0, 10.0 ng/ml increased 3H-TdR incorporation into cultured skin fibroblasts dose-dependently. Ang Ⅱ and TGF-β at lower doses (1×10-10 mol/L and 0.1 ng/ml, respectively) did not affect 3H-TdR incorporation into fibroblasts (Pgt;0.05), whereas co-administration of both Ang Ⅱ and TGF-β at these doses significantly increased 3H-TdR incorporation intofibroblasts(Plt;0.05). Ang Ⅱ at 1×10-7 mol/L or TGF-β at 10.0 ng/ml significantly increased ERK phosphorylation of fibroblasts after stimulation (Plt;0.01). Smaller doses of Ang Ⅱ (1×10-10 mol/L) or TGF-β (0.1 ng/ml) did not influence ERKphosphorylation of fibroblasts, whereas co-administration of Ang II and TGF-β at these doses significantly enhanced ERK phosphorylation (Plt;0.05). Total protein levels of ERK did not differ at different doses. Conclusion These results indicate that Ang Ⅱ and TGF-β synergistically increase skin fibroblast proliferation, which is at least partly via enhancement of ERK activity.
目的:探讨血管紧张素Ⅱ受体拮抗剂(ARB)对PAF患者P波离散度的影响。方法:观察48 例阵发性AF患者的最宽P 波和P 波离散度,并与ARB干预治疗3 个月后进行对比分析。结果:ARB治疗3个月后最宽P波、P 波离散度及P 波离散度≥40 ms的例数与治疗前比较差异有统计学意义 (Plt;0.05或lt;0.01)。结论:ARB能减轻PAF患者心房结构重构及电重构,减少AF的发生。
Objective To investigate the preventive effect of simvastatin，a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor，on hypoxic pulmonary hypertension and the relation between it and the angiotensin Ⅱ receptor-1（AT1R） expression in pulmonary arteriole.Methods Thirty male Sprague-Drawley rats were randomly allocated into three groups：a control group，a hypoxic group and a simvastatin preventive group.The animal model of hypoxic pulmonary hypertension was established by exposing the rats to normobaric hypoxic condition（8 h×6 d×3 w），and the preventive group were treated with simvastatin 10 mg/kg before hypoxic processing while the control and hypoxic groups were treated with sodium chloride.The mean pulmonary pressure（mPAP），serum cholesterol concentration，right ventricular hypertrophy index [RV/（LV+S）]，percentage of the wall thickness in the external diameter（WT%），percentage of the wall area in the total vascular area（WA%），and the AT1R expression in pulmonary arterioles were measured.Results When compared with the hypoxic group，in the preventive group，the mPAP and RV/（LV+S）obviously reduced [（22.6±3.86）mm Hg vs （29.3±2.27）mm Hg，（25.13±0.75）% vs （33.18±1.58）%，Plt;0.01 respectively]，the indices of wall thickness of rat pulmonary arteriole and area also decreased significantly [WT%：（15.98±1.96）% vs （25.14±1.85）%；WA%：（54.60±3.94）% vs 74.77±4.52）%；Plt;0.01 respectively]，and the positive degree of AT1R still lessened noticeably（1.23±0.09 vs 1.57±0.13，Plt;0.01）.All of the indices above in the hypoxic group increased markedly compared with the control group（Plt;0.01 respectively）.However，the differences of serum cholesterol among three groups were not significant（Pgt;0.05）.Conclusions Simvastatin can suppress the expression of AT1R in pulmonary vessel and prevent hypoxic pulmonary hypertension.
Objective To explore the role of renin-angiotensin system( RAS) in acute lung injury( ALI) /acute respiratory dysfunction syndrome( ARDS) by using amouse cecal ligation and puncture ( CLP)model.Methods The ALI/ARDS animal models were assessed bymeasuring blood gas, wet/dry lung weight ratio( W/D) , and lung tissue histology 18 hours after CLP operation. After the ALI/ARDS models was successfully established, immunohistochemistry, western blotting and radioimmunity were used to investigate the changes of several key enzymes of RAS, such as ACE, ACE2 and Ang Ⅱ. In addition, two groups of animals received a separate intraperitoneal injection of angiotensin-converting enzyme ( ACE) inhibitor captopril or recombinant mouse ACE2 ( rmACE2) after CLP, then the changes of RAS in ALI/ARDS modelswere observed. Results The extensive lung injuries can be observed in the lung tissues from CLP-treated animals 18 hours after operation. The CLP-induced ALI/ARDS led to an increase in the wet/dry weight ratio of the lung tissues, and a decrease in the PaO2 /FiO2 [ ( 194. 3 ±23. 9) mm Hg vs ( 346. 7 ±20. 5) mm Hg,P lt;0. 01] . Immunohistochemistry and western blotting tests of the lung tissues from CLP-treated animals showed a decrease in the ACE2 protein level. However, in both the CLP and sham mice there were no significant differences between the two groups. CLP markedly increased Ang Ⅱ level in lungs and plasma of mice, and RAS drugs significantly impacted the Ang Ⅱ levels of mice. Compared with the CLP group,captopril or rmACE2 led to a decrease of the Ang Ⅱ level in mice [ Lung: ( 1. 58 ±0. 16) fmol /mg,( 1. 65 ±0. 21) fmol /mg vs ( 2. 38 ±0. 41) fmol /mg; Plasma: ( 178. 04 ±17. 87) fmol /mL, ( 153. 74 ±10. 24) fmol /mL vs ( 213. 38 ± 25. 44) fmol /mL] . Conclusions RAS activation is one of the characteristics of CLP-induced ALI/ARDS in mice models. ACE and ACE2 in RAS have a different role in the regulation of AngⅡ synthesis, while ACE has a positive effect in generating AngⅡ, and ACE2 shows a negative effect.
ObjectiveTo investigate the optimal administration combination of β-aminopropionitrile (BAPN) and Angiotensin Ⅱ (Ang-Ⅱ) in the establishment of SD rat aortic dissection (AD) model and the related complications. MethodsForty-two three-week-old male SD rats were randomly divided into 7 groups: a group A (0.25% BAPN), a group B (0.40% BAPN), a group C (0.80% BAPN), a group D [1 g/(kg·d) BAPN], a group E [1 g/(kg·d) BAPN+1 μg/(kg·min) saline], a group F [1 g/(kg·d) BAPN+1 μg/(kg·min) Ang-Ⅱ] and a group G (control group). There were 6 rats in each group. The intervention period was 4 weeks (groups E and F were 4 weeks+5 days). Rats were dissected immediately if they died during the experiment. After the intervention, the surviving rats were sacrificed by pentobarbital sodium, and the whole aorta was separated and retained. Hematoxylin-eosin staining was used to observe the changes of aorta from the pathological morphology. ResultsThere was no statistical difference in the survival rate among the groups after 4 weeks of BAPN intervention (P>0.05). After 5 days of mini-osmotic pumps implantation, the survival rate of rats was higher in the group E than that in the group F (P=0.008), and the incidence of AD in the group E was lower than that in the group F (P=0.001). BAPN could affect the food and water intake of rats. After BAPN intervention for 4 weeks, the body weight of rats in the group G was higher than those in the intervention groups (P<0.05). BAPN combined with Ang-Ⅱ could make the aortic intima thick, elastic fiber breakage, arrangement disorder, and inflammatory cell infiltration in rats, which conformed to the pathological and morphological changes of AD. BAPN could also affect mental state and gastrointestinal tract. ConclusionThe combination of BAPN [1 g/(kg·d)] and Ang-Ⅱ [1 μg/(kg·min)] can stably establish AD model in rats, which will provide a stable carrier for further study of the pathogenesis and therapeutic targets of AD. However, the complications in this process are an unstable factor. How to balance the influence of BAPN on other tissues and organs in the process of AD model establishment remains to be further studied.