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.
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.
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.
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.
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.
Objective To systematically review the efficacy of total glycosides extracted from Rehmannia glutinosa Libosch leaf in the treatment of diabetic nephropathy. Methods Databases including PubMed, EMbase, MEDLINE, The Cochrane Library, Web of Science, CNKI, WanFang Data and VIP were electronically searched to collect randomized controlled trials of total glycosides from Rehmannia glutinosa Libosch for diabetic nephropathy from inception to May 30th, 2021. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. RevMan 5.4 software was then used to perform meta-analysis. Results A total of 7 RCTs involving 504 patients were included. The results of meta-analysis showed that there were no significant differences in creatinine levels (MD=−1.71, 95%CI −3.97 to 0.56, P=0.14) and urea (MD=−0.18, 95%CI −0.44 to 0.08, P=0.19) between the two groups. In terms of regulating proteinuria, the urinary albumin excretion rate (MD=−39.41, 95%CI −48.46 to −30.36, P<0.000 01), urinary microalbumin (MD＝−9.94, 95%CI −12.16 to −7.73, P<0.000 01), and 24-hour urinary protein (MD=−0.67, 95%CI −0.85 to −0.49, P<0.000 01) were all lower in the treatment group compared with control group. However, there were no differences between groups in terms of blood glucose metabolism as indicated by changes in levels of the long-term blood glucose metabolism indicator (HbA1c: MD=−0.16, 95%CI −0.67 to 0.35, P=0.53). Only one study suggested that short-term blood glucose metabolism indicators, fasting blood glucose and postprandial blood glucose levels were not different between groups. In terms of blood lipid metabolism, only one study suggested glycoside treatment produced lower serum levels of cholesterol and triglycerides compared with control group. Conclusions Current evidence suggests that adjunctive therapy with total Rehmannia glutinosa Libosch glycosides can benefit diabetic nephropathy patients more than angiotensin II receptor inhibitor or pancreatic kininogen by alleviating proteinuria and likely improving lipid metabolism. However, no benefit is observed in terms of renal function improvement or blood glucose metabolism. Due to limited quality and quantity of included studies, more high-quality studies are required to verify the above conclusions.
Vascular smooth muscle cells (VSMCs) phenotype switching plays an essential role in the pathogenesis of various vascular diseases. The present study aims to investigate the role of receptor-interacting protein kinases 1(RIPK1) in VSMCs phenotypic switching induced by Angiotensin Ⅱ(Ang Ⅱ). Expression of mRNA and protein of RIPK1, markers of VSMCs phenotypic switching and secretion, phosphorylation of the P65 subunit of NF-κB were measured by real-time PCR and Western blot. Meanwhile, EdU incorporation assay and wound scratch assay were performed to determine the cell proliferation and migration respectively. At the same time, Necrostatin-1(Nec-1, an known RIPK1 inhibitor) and RIPK1-specific small interference RNA (siRNA) were used to inhibit the expression of RIPK1. The experimental data demonstrated that the mRNA and protein levels of RIPK1 and P65 phosphorylation were increased significantly in the process of VSMC phenotypic switching induced by Ang II. Moreover, the expression of RIPK1 and P65 phosphorylation were significantly down-regulated in VSMCs pretreated with Nec-1 or trans-fected with RIPK1-siRNA. Furthermore, the proliferation, secretion and migration of VSMCs were also markedly suppressed after inhibition of RIPK1 by Nec-1 or its specific siRNA. The results suggested that RIPK1 might be involved in VSMC phenotypic switching induced by Ang II, which was possibly via up-regulating the NF-κB signaling pathway.
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.