Angiotension-Ⅱ(A-Ⅱ) receptor maximal binding capacity (Bmax) and dissociation constants (Kd) of different blood vessels in rats with prehepatic portal hypertension were studied by radioligand binding analysis. The r...Angiotension-Ⅱ(A-Ⅱ) receptor maximal binding capacity (Bmax) and dissociation constants (Kd) of different blood vessels in rats with prehepatic portal hypertension were studied by radioligand binding analysis. The results showed that the A-Ⅱreceptor Bmax. in the thoracic aorta, superior mesenteric artery and portal vein of portal hypertensive animals (113. 7±19. 4 fmol/mg protein, 206.9 ±39. 3 fmol/mg protein and 31. 5±9. 2 fmol/mg protein respectively ) was all significantly lower than that of controls (146. 8±24. 5 fmol/mg protein, 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 portal hypertensive animals (1. 03±0.11 nmol/L) compared with that in controls (0. 88±0. 08 nmol/L, P<0. 05). In the thoracic aorta and portal vein, the A-Ⅱ receptor Kd in portal hypertensive animals was slightly higher than that in controls, but no significant difference was observed between the two groups. The results suggested that the vascular hyporesponsiveness to A-Ⅱ in portal hypertension was caused partially by a reduction in number and a decrease in affinity of vascular A- Ⅱ receptors, and these changes might possibly lead to the formation of hyperdynamic circulation.展开更多
The expression vector of shRNA targeted to the rat angiotensin Ⅱ receptor gene was constructed and the efficacy of siRNAs to modulate the expression of target gene in the in vitro cultured mammalian cells was investi...The expression vector of shRNA targeted to the rat angiotensin Ⅱ receptor gene was constructed and the efficacy of siRNAs to modulate the expression of target gene in the in vitro cultured mammalian cells was investigated for antihypertensive therapy in spontaneous hypertensive rat (SHR) at post-transcriptional level. The sense and antisense RNA oligonucleotides strands targeting angiotensin Ⅱ receptor mRNA were synthesized individually according to the sequence of the rat angiotensin Ⅱ receptor. For preparation of duplexes, sense- and antisense-stranded oligonucleotides were mixed and annealed, and the annealed duplexes were cloned into the pGenesil-1 vector. The rat glioma cells were transfected with constructed pGenesil-1-shRNA plasmid and scrambled plasmid. The cultured cells were collected at different phases. RT-PCR and Western blot were performed. The AT1 mRNA and protein levels behaved ultimately same. Compared to control after 48 h, AT1 mRNA levels were decreased to 35.5%±3.0 %, and the levels reached their lowest point after 72 h (20.7% ±4 % of control). At 24 and 48 h, AT1 protein was reduced to 46.9%±4.2% and 36.98%±3.7% respectively compared to control and a maximum reduction was observed after 72 h of incubation (28.1%± 4% compared to controls). Plasmid-based shRNA expression systems targeted against the rat angiotensin Ⅱ receptor gene were generated successfully. The shRNAs with a 22-nt stem and a short loop were cleaved into small interfering dsRNA (siRNA) by the Dicer. The in vitro transcribed siRNA enables the effective silencing of gene expression to the target mRNA and leads to effective inhibition of translation of proteins and will be lay the foundation of application of gene silencing technology to hypertensive rats.展开更多
The expression of angiotensin Ⅱ type 1 receptor (AT1R) and angiotensin Ⅱ type 2 receptor (AT2R) in aldosterone-producing adenoma (APA) of the adrenal gland was detected, and their relationship with clinical indexes ...The expression of angiotensin Ⅱ type 1 receptor (AT1R) and angiotensin Ⅱ type 2 receptor (AT2R) in aldosterone-producing adenoma (APA) of the adrenal gland was detected, and their relationship with clinical indexes of APA was analyzed. The mRNA expression of AT1R and AT2R in 50 cases of APA and tissues adjacent to tumors and 12 cases of normal adrenal tissues was detected by using reverse transcriptase polymerase chain reaction (RT-PCR). The expression of AT1R and AT2R proteins in paraffin-embedded slices of tissue was detected by immunohistochemistry. The expression of AT1R in adenoma, tissues adjacent to tumor, and normal tissues of the adrenal gland showed no significant differences. The expression of AT2R in APA tissue was lower than that in normal adrenal gland tissues (P<0.05). Correlation analysis of the mRNA expression level of AT2R and clinical data from patients demonstrated that AT2R expression was negatively related to plasma aldosterone concentration (PAC) (r=-0.467, P<0.05), but positively related with plasma renin activity (PRA) (r=0.604, P<0.05). It is concluded that down-regulation of the AT2R expression is possibly related with the tumorigenesis of APA.展开更多
AIM: To investigate the effect of angiotensin II type 1 receptor blocker (ARB) and angiotensin converting enzyme inhibitor (ACEI) on intraocular growth factors and their receptors in streptozotocin-induced diabet...AIM: To investigate the effect of angiotensin II type 1 receptor blocker (ARB) and angiotensin converting enzyme inhibitor (ACEI) on intraocular growth factors and their receptors in streptozotocin-induced diabetic rats. METHODS: Forty Sprague-Dawley rats were divided into 4 groups: control, diabetes mellitus (DM), candesartan- treated DM, and enalapril-treated DM (each group, n---10). After the induction of DM by streptozotocin, candesartan [ARB, 5 mg/(kg · d)] and enalapril [ACEI, 10 mg/(kg · d)] were administered to rats orally for 4Wko Vascular endothelial growth factor (VEGF) and angiotensin II (Ang II) concentrations in the vitreous were measured using enzyme-linked immunosorbent assays, and VEGF receptor 2 and angiotensin II type 1 receptor (ATIR) levels were assessed at week 4 by Western blotting. RESULTS: Vitreous Ang II levels were significantly higher in the DM group and candesartan-treated DM group than in the control (P=0.04 and 0.005, respectively). Vitreous ATIR increased significantly in DM compared to the other three groups (P〈0.007). Candesartan-treated DM rats showed higher vitreal ATIR concentration than the enalapril-treated DM group and control (P〈0.001 and P=0.005, respectively). No difference in vitreous Ang II and ATIR concentration was found between the enalapril- treated DM group and control. VEGF and its receptor were below the minimum detection limit in all 4 groups. CONCLUSION: Increased Ang II and ATIR in the hyperglycemic state indicate activated the intraocular renin-angiotensin system, which is inhibited more effectively by systemic ACEI than systemic ARB.展开更多
Objective: To investigate the effect of activation of angiotensin Ⅱ(AngⅡ) type 1 (AT1) receptors in the median preoptic nucleus (MnPO) of rats on renal sodium excretion. Methods: After anesthesia, the rats w...Objective: To investigate the effect of activation of angiotensin Ⅱ(AngⅡ) type 1 (AT1) receptors in the median preoptic nucleus (MnPO) of rats on renal sodium excretion. Methods: After anesthesia, the rats were injected into the MnPO via an implanted cannula. Urine samples were collected via a bladder cannula, and the urine sodium concentration was assayed with flame spectrophotometry. The serum level of endogenous digitalis-like factor (EDLF) and Na^+,K^+-ATPase activity in the renal cortex tissue were assayed respectively with a radioimmunoassay and with an ammonium molybdophosphate-based kit. Results: Both the urinary volume and the sodium excretion peaked 60 min after AngⅡ was administered into the MnPO. The responses were accompanied by an increase in serum EDLF and a decrease in Na^+,K^+-ATPase activity in the renal cortex. The responses of diuresis and natriuresis, as well as an increase in serum EDLF and a decrease in Na^+,K^+-ATPase activity in the renal cortex induced by MnPO adminstration with AngⅡ were inhibited by pior treatment with the AngⅡ receptor blocking agent losartan into the MnPO. Conclusion: These results suggest that activation of AT1 receptors in the MnPO of rat induces diuretic and natriuretic responses. The responses are associated with an increase release of EDLF and with the inhibition of Na^+,K^+-ATPase activity in renal cortex tissue.展开更多
The expression of the products of IGF-Ⅱ,IGF-Ⅱ receptors(IGF-Ⅱ-R)and CSF-Ⅰ re-ceptors(CSF-Ⅰ-R)was observed in 17 cases of human primary hepatocellular carcinoma(PHC)and the juxtacancerous liver tissue with immunoh...The expression of the products of IGF-Ⅱ,IGF-Ⅱ receptors(IGF-Ⅱ-R)and CSF-Ⅰ re-ceptors(CSF-Ⅰ-R)was observed in 17 cases of human primary hepatocellular carcinoma(PHC)and the juxtacancerous liver tissue with immunohistochemistry(ABC),Western blot and North-ern blot technique,It was found that the expression of IGF-Ⅱ,IGF-Ⅱ-R and CSF-Ⅰ-R was signif-icantly higher in PHC than in normal liver tissue and the expression of IGF-Ⅱ and IGF-Ⅱ-R wasremarkably higher in the juxtacancerous liver tissue from PHC patients than in PHC proper.Itwas noteworthy that the expression of IGF-Ⅱ in both the cancer proper and the juxtacancerousliver tissue was characterized by its fetal type.Besides,the expression of CSF-Ⅰ-R was signifi-cantly higher in PHC than in the juxtacancerous liver tissue.It is believed that the abnormal ex-pression of IGF-Ⅱ,IGF-Ⅱ-R and CSF-I-R in PHC and the juxtacaneerous liver tissue might berelated to the autocrine mechanism of human PHC.展开更多
The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was con...The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was considered a zoonotic disease, the virus has also spread among humans via respiratory secretions. The expression and distribution of angiotensin converting enzyme type 2(ACE2) in various human organs might also show other possible infection routes. High ACE2 ribonucleic acid expression has been identified in the gastrointestinal tract(GI) indicating its importance as a possible infection pathway of SARS-CoV-2. ACE2 induces viral entry into the host and most importantly has been found to be associated with the function of the gut. Its deficiency has been implicated in several pathologies such as colorectal inflammation. The renin-angiotensin system(RAS) is an essential regulatory cascade operating both at a local tissue level and at the systemic or circulatory level. The RAS may be important in the pathogenesis of chronic liver disease and is associated with the up-regulation of ACE2. Thus, the aim of this review is firstly, the analysis of some important general and genome characteristics of SARS-CoV-2 and secondly, and most importantly, to focus on the utility of ACE2 receptors in both SARS-CoV-2 replication and pathogenesis, especially in the GI tract.展开更多
Regulation of the number of aetivin receptors that are present in the cell membrane plays a key role in the modulation of cellular responses to activin. In order to find the regulators, a novel protein ARIPzip, intera...Regulation of the number of aetivin receptors that are present in the cell membrane plays a key role in the modulation of cellular responses to activin. In order to find the regulators, a novel protein ARIPzip, interacting with activin type II receptors, was searched and identified by using yeast two-hybrid screening. ARIPzip is a splicing variant of ARIP2. This has been discussed previously. ARIPzip can specifically interact with ActR Ⅱ A, and is widely distributed in mouse tissues. Overexpression of ARIPzip can cause the activin-induced transcriptional activities to increase in a dose-dependent manner while the overexpression of ARIV2 can decrease these activities. These data suggest that the C-terminal rezions of ARIP2 and ARIPzip are involved in the regulation of activin signaling.展开更多
Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes(α, β, γ, and ...Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes(α, β, γ, and δ). The genes undergo transactivation or transrepression under specific mechanisms that lead to the induction or repression of target gene expression. As is the case with other nuclear receptors, all four PPAR isoforms contain five or six structural regions in four functional domains; namely, A/B, C, D, and E/F. PPARs have many functions, particularly functions involving control of vascular tone, inflammation, and energy homeostasis, and are, therefore, important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. Hence, PPARs also represent drug targets, and PPARα and PPARγ agonists are used clinically in the treatment of dyslipidemia and type 2 diabetes mellitus, respectively. Because of their pleiotropic effects, they have been identified as active in a number of diseases and are targets for the development of a broad range of therapies for a variety of diseases. It is likely that the range of PPARγ agonist therapeutic actions will result in novel approaches to lifestyle and other diseases. The combination of PPARs with reagents or with other cardiovascular drugs, such as diuretics and angiotensin Ⅱ receptor blockers, should be studied.This article provides a review of PPAR isoform characteristics, a discussion of progress in our understanding of the biological actions of PPARs, and a summary of PPAR agonist development for patient management. We also include a summary of the experimental and clinical evidence obtained from animal studies and clinical trials conducted to evaluate the usefulness and effectiveness of PPAR agonists in the treatment of lifestyle-related diseases.展开更多
Cerebral ischemia-reperfusion(I/R)injury is a crucial factor that impacts the prognosis of recanalization therapy for acute ischemic stroke(AIS).It has been found that the brain renin-angiotensin system,especially the...Cerebral ischemia-reperfusion(I/R)injury is a crucial factor that impacts the prognosis of recanalization therapy for acute ischemic stroke(AIS).It has been found that the brain renin-angiotensin system,especially the angiotensinⅡtype 1 receptor(AT1R)pathway,plays a significant role in cerebral I/R injury.This pathway is involved in processes such as oxidative stress,neuroinflammation,apoptosis,and it affects cerebrovascular autoregulation and the maintenance of blood-brain barrier.AT1R blocker(ARB),widely used as an antihypertensive agent,has demonstrated stroke prevention capabilities in numerous prospective studies,independent of its antihypertensive characteristics.Studies focusing on neurological diseases like Alzheimer's disease,Parkinson's disease,and cognitive impairment have confirmed that ARBs exhibit neuroprotective effects and aid in improving neurological functions.Preclinical studies have shown that ARBs can reduce infarct volume and brain edema,inhibit multiple signaling pathways associated with I/R injury,restore energy levels in damaged brain regions,and rescue the penumbra by promoting neovascularization in cerebral I/R models.These findings suggest that ARBs have potential to become a novel category of neuroprotecting agents for clinical treatment of Als.Therefore,this review primarily provides a theoretical foundation and practical evidence for the future clinical utilization of ARBs as neuroprotective agents following reperfusion therapy for Als.It outlines the role of cerebral I/R injury through the AT1R pathway and highlights the research progressmadeonARBs in I/Rmodels.展开更多
Background:Exercise is beneficial for muscle atrophy.Peroxisome proliferator-activated receptor gamma(PPARγ) and microRNA-29 b(miR-29 b) have been reported to be responsible for angiotensinⅡ(AngⅡ)-induced muscle at...Background:Exercise is beneficial for muscle atrophy.Peroxisome proliferator-activated receptor gamma(PPARγ) and microRNA-29 b(miR-29 b) have been reported to be responsible for angiotensinⅡ(AngⅡ)-induced muscle atrophy.However,it is unclear whether exercise can protect AngⅡ-induced muscle atrophy by targeting PPARγ/miR-29 b.Methods:Skeletal muscle atrophy in both the control group and the run group was established by AngⅡ infusion;after 1 week of exercise training,the mice were sacrificed,and muscle weight was determined.Myofiber size was measured by hematoxylin-eosin and wheat-germ agglutinin staining.Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling staining.The expression level of muscle atrogenes,including F-box only protein 32(FBXO32,also called Atrogin-1) and muscle-specific RING-finger 1(MuRF-1),the phosphorylation level of protein kinase B(PKB,also called AKT)/forkhead box 03 A(FOX03 A)/mammalian target of rapamycin(mTOR) pathway proteins,the expression level of PPARγ and apoptosis-related proteins,including B-cell lymphoma-2(Bcl-2),Bcl-2-associated X(Bax),cysteine-aspartic acid protease 3(caspase-3),and cleaved-caspase-3,were determined by western blot.The expression level of miR-29 b was checked by reversetranscription quantitative polymerase chain reaction.A PPARγ inhibitor(T0070907) or adeno-associated virus serotype-8(AAV8)-mediated miR-29 b overexpression was used to demonstrate whether PPARγ activation or miR-29 b inhibition mediates the beneficial effects of exercise in AngⅡ-induced muscle atrophy.Results:Exercise can significantly attenuate AngⅡ-induced muscle atrophy,which is demonstrated by increased skeletal muscle weight,cross-sectional area of myofiber,and activation of AKT/mTOR signaling and by decreased atrogenes expressions and apoptosis.In AngⅡ-induced muscle atrophy mice models,PPARγ was elevated whereas miR-29 b was decreased by exercise.The protective effects of exercise in AngⅡ-induced muscle atrophy were inhibited by a PPARγ inhibitor(T0070907) or adeno-associated virus serotype-8(AAV8)-mediated miR-29 b overexpression.Conclusion:Exercise attenuates AngⅡ-induced muscle atrophy by activation of PPARγ and suppression of miR-29 b.展开更多
OBJECTIVE To investigate the vasorelaxant effect of pinocembrin(5,7-dihydroxyflavanone),one of the main flavonoids in propolis,on angiotensinⅡ(AngⅡ)induced vasoconstriction and the molecular mechanism of action.METH...OBJECTIVE To investigate the vasorelaxant effect of pinocembrin(5,7-dihydroxyflavanone),one of the main flavonoids in propolis,on angiotensinⅡ(AngⅡ)induced vasoconstriction and the molecular mechanism of action.METHODS The isometric vascular tone was measured in thoracic aortic rings from SD rat,and the effects of pinocembrin on the single dose and concentration cumulative response curves of AngⅡ were recorded.The binding of pinocembrin to the angiotensin type 1 receptor(AT1R)was studied by using molecule docking analysis.Intracellular[Ca2+]([Ca2+]i)was measured with Fura2/AM in VSMCs.The phosphorylation levels of myosin light chain 2(MLC2)and myosin phosphatase target unit 1(MYPT1),and protein level of Rho kinase 1(ROCK1)in the rat aortic rings were detected by Western blotting.RESULTS Pinocembrin was observed to inhibit AngⅡ-induced vasoconstriction in rat aortic rings with either intact or denuded endothelium.In endothelium-denuded tissues,pinocembrin(pD′2 4.28±0.15)counteracted the contractions evoked by cumulative concentrations of AngⅡ.In a docking model,pinocembrin showed effective binding at the active site of AT1R.Pinocembrin was shown to inhibit both AngⅡ-induced Ca2+ release from internal stores and Ca2+ influx.Moreover,the increase in the phosphorylation of MLC2 and MYPT1,and the increased protein level of ROCK1 induced by AngⅡ was blocked by pinocembrin.CONCLUSION Pinocembrin inhibits AngⅡ-induced rat aortic ring contraction in a Ca2+-dependent and Ca2+-independent manner via blocking AT1R.展开更多
Background Angiotensin Ⅱ type 1 receptor (ATR1) / Angiotensin Ⅱ type 2 receptor (ATR2) usually interact with each other in their expression and physiological functions, and nitric oxide (NO) is always involved in AT...Background Angiotensin Ⅱ type 1 receptor (ATR1) / Angiotensin Ⅱ type 2 receptor (ATR2) usually interact with each other in their expression and physiological functions, and nitric oxide (NO) is always involved in ATR1 / ATR2 regulation in vivo. Endothelial cells play a crucial role in the maintenance of vascular function and in the prevention of cardiovascular diseases. Objectives To investigate the effects of angiotensin Ⅱ (Ang Ⅱ) and ATR1 blocker valsartan on ATR1, ATR2 expression and their relation with endothelial nitric oxide synthase (eNOS) expression, and NO production in cultured vascular endothelial cells. Methods Human umbilical vein endothelial cell line (HUVEC) and bovine aortic endothelial cell (BAEC) were used. BAEC were isolated from aorta of newborn calf by enzyme digestion and cells of 3-5 passages were used. Cells were incubated with vehicle, Ang Ⅱ, valsartan, or Ang Ⅱ plus valsartan respectively for various periods. ATR1, ATR2, eNOS expression and NO production were detected. Results Incubation with AngⅡ or valsartan apparently downregulated ATR1 mRNA and protein expression in vascular endothelial cells, and the combination effect of the two drugs were more apparent. Ang Ⅱ showed a transient slightly promotive effect on eNOS and NO generation in BAEC and an apparently inhibitory effect with prolonged incubation, while valsartan can apparently reverse those effects. Conclusions Both Ang Ⅱ and valsartan downregulated the expression of ATR1 in vascular endothelial cells. The synergistic effect of the two drugs was more apparent. Prolonged incubation with Ang Ⅱ can apparently inhibit eNOS expression and NO production in endothelial cells, while valsartan can apparently reverse that inhibitory effect.展开更多
Background It's established that Angiotensin Ⅱ and its receptors are involved in intimal hyperplasia after balloon injury and stent restenosis. Recent evidence also suggests that statins have some anti-intimal hyper...Background It's established that Angiotensin Ⅱ and its receptors are involved in intimal hyperplasia after balloon injury and stent restenosis. Recent evidence also suggests that statins have some anti-intimal hyperplasia effects. In this study, the effect of Rosuvastatin on expression of angiotensin Ⅱ receptors in rat aortic endothelium after balloon injury is therefore investigated. Methods All 52 Wistar Kyoto rats were established to aorta injury models by 2F balloon catheter, then were randomly divided into sham operation group, aorta injury group and Rosuvastatin-treatment group. After 14 days, the aortic specimens of the animals were harvested and performed immunohistochemistry and determination of molecular biology. Results The results showed that (i) The 14 days-balloon injury induced obvious intima thickening (P 〈 0.01), however, the phenomenon was reduced by 14 daystreatment with Rosuvastatin (P 〈 0.01). (ii) The expressions of angiotention Ⅱ type Ⅰ (AT1) and type Ⅱ (AT2) receptor mRNA and protein were markedly up-regulated by the balloon injury (P 〈 0.01), after 14 days-treatment with Rosuvastatin, the expression of AT1 receptor mRNA and its protein was decreased (P 〈 0.01), but the expression of AT2 receptor mRNA and its protein was further increased (P 〈 0.05). Conclusion In this study, we observed that the balloon injury induced-intima thickening was reduced by Rosuvastatin in rats, which might be linked with the regulation of expression of angiotensin Ⅱ receptors.展开更多
Background Many studies have suggested that angiotensin Ⅱ (Ang Ⅱ) and its receptors may be involved in the development of asthma. However, the expression of angiotensin Ⅱ receptors (AGTR) is not clear in the lu...Background Many studies have suggested that angiotensin Ⅱ (Ang Ⅱ) and its receptors may be involved in the development of asthma. However, the expression of angiotensin Ⅱ receptors (AGTR) is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma. Methods Rats were sensitized with ovalbumin (OVA) for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan (15, 30, 50 mg.kg-1.d-1) or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting. Results AGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats (50 mg.kg-1.d-1) were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-β1 and PDGF in BALE Conclusions AGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma. Ang Ⅱ and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats. Valsartan, a AGTR1 antagonist, could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats.展开更多
To explore the relation of angiotensin-converting enzyme (ACE) and angiotensin Ⅱ type 1 receptor (AT1R) gene polymorphism with coronary heart disease (CHD) and the severity of coronary artery stenosis, 130 CHD ...To explore the relation of angiotensin-converting enzyme (ACE) and angiotensin Ⅱ type 1 receptor (AT1R) gene polymorphism with coronary heart disease (CHD) and the severity of coronary artery stenosis, 130 CHD patients who underwent coronary angiography were examined for the number of affected coronary vessels (≥75% stenosis) and coronary Jeopardy score. The insertion/deletion of ACE gene polymorphism and AT1R gene polymorphism (an A→C transversion at nucleotide position 1166) were detected by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) in CHD patients and 90 healthy serving as controls. The resuits showed that DD genotype and of ACE were more frequent in CHD patients than that in control group (38.5% vs 14.4%, P〈0.001). The frequency of the ATIR A/C genotypes did not differ between the patients and the controls (10% vs 13.1%, P〉0.05). The relative risk associated with the ACE-DD was increased by AT1R-AC genotype. Neither the number of affected coronary vessels nor the coronary score differed among the ACE I/D genotypes (P〉0.05). But the number of affected coronary vessels and the coronary score were significantly greater in the patients with the AT1R-AC genotype than in those with the AA genotype (P〈0.05). In conclusion, DD genotype may be risk factor for CHD and MI in Chinese people, and is not responsible for the development of the coronary artery stenosis. The AT1R-C allele may increase the relative risk associated with the ACE-DD genotype, and may be involved in the development of the stenosis of coronary artery.展开更多
AIM: To investigate the roles of nuclear factor(NF)-κB and angiotensin Ⅱ receptor type 1(AT1R) in the pathogenesis of non-alcoholic fatty liver disease(NAFLD).METHODS: Forty-two healthy adult male SpragueDawley rats...AIM: To investigate the roles of nuclear factor(NF)-κB and angiotensin Ⅱ receptor type 1(AT1R) in the pathogenesis of non-alcoholic fatty liver disease(NAFLD).METHODS: Forty-two healthy adult male SpragueDawley rats were randomly divided into three groups:the control group(normal diet), the model group,and the intervention group(10 wk of a high-fat diet feeding, followed by an intraperitoneal injection of PDTC); 6 rats in each group were sacrificed at 6, 10,and 14 wk. After sacrifice, liver tissue was taken,paraffin sections of liver tissue specimens were prepared, hematoxylin and eosin(HE) staining was performed, and pathological changes in liver tissue(i.e., liver fibrosis) were observed by light microscopy.NF-κB expression in liver tissue was detected by immunohistochemistry, and the expression of AT1 R in the liver tissue was detected by reverse transcriptionpolymerase chain reaction(RT-PCR). The data are expressed as mean ± SD. A two-sample t test was used to compare the control group and the model group at different time points, paired t tests were used to compare the differences between the intervention group and the model group, and analysis of variance was used to compare the model group with the control group. Homogeneity of variance was analyzed with single factor analysis of variance. H variance analysis was used to compare the variance. P < 0.05 wasconsidered statistically significant.RESULTS: The NAFLD model was successful after 6wk and 10 wk. Liver fibrosis was found in four rats in the model group, but in only one rat in the intervention group at 14 wk. Liver steatosis, inflammation, and fibrosis were gradually increased throughout the model. In the intervention group, the body mass,rat liver index, serum lipid, and transaminase levels were not increased compared to the model group.In the model group, the degree of liver steatosis was increased at 6, 10, and 14 wk, and was significantly higher than in the control group(P < 0.01). In the model group, different degrees of liver cell necrosis were visible and small leaves, punctated inflammation,focal necrosis, and obvious ballooning degeneration were observed. Partial necrosis and confluent necrosis were observed. In the model group, liver inflammatory activity scores at 6, 10, and 14 wk were higher than in the control group(P < 0.01). Active inflammation in liver tissue in the intervention group was lower than in the model group(P < 0.05). HE staining showed liver fibrosis only at 14 wk in 4/6 rats in the model group and in 1/6 rats in the intervention group. NF-κB positive cells were stained yellow or ensemble yellow,and NF-κB was localized in the cytoplasm and/or nucleus. The model group showed NF-κB activation at6, 10, and 14 wk in liver cells; at the same time points,there were statistically significant differences in the control group(P < 0.01). Over time, NF-κB expression increased; this was statistically lower(P < 0.05) at14 weeks in the intervention group compared to the model group, but significantly increased(P < 0.05)compared with the control group; RT-PCR showed that AT1 R mRNA expression increased gradually in the model group; at 14 wk, the expression was significantly different compared with expression at 10 weeks as well as at 6 weeks(P < 0.05). In the model group, AT1 R mRNA expression was significantly higher than at the same time point in the control group(P <0.01).CONCLUSION: With increasing severity of NAFLD,NF-κB activity is enhanced, and the inhibition of NF-κB activity may reduce AT1 R mRNA expression in NAFLD.展开更多
文摘Angiotension-Ⅱ(A-Ⅱ) receptor maximal binding capacity (Bmax) and dissociation constants (Kd) of different blood vessels in rats with prehepatic portal hypertension were studied by radioligand binding analysis. The results showed that the A-Ⅱreceptor Bmax. in the thoracic aorta, superior mesenteric artery and portal vein of portal hypertensive animals (113. 7±19. 4 fmol/mg protein, 206.9 ±39. 3 fmol/mg protein and 31. 5±9. 2 fmol/mg protein respectively ) was all significantly lower than that of controls (146. 8±24. 5 fmol/mg protein, 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 portal hypertensive animals (1. 03±0.11 nmol/L) compared with that in controls (0. 88±0. 08 nmol/L, P<0. 05). In the thoracic aorta and portal vein, the A-Ⅱ receptor Kd in portal hypertensive animals was slightly higher than that in controls, but no significant difference was observed between the two groups. The results suggested that the vascular hyporesponsiveness to A-Ⅱ in portal hypertension was caused partially by a reduction in number and a decrease in affinity of vascular A- Ⅱ receptors, and these changes might possibly lead to the formation of hyperdynamic circulation.
文摘The expression vector of shRNA targeted to the rat angiotensin Ⅱ receptor gene was constructed and the efficacy of siRNAs to modulate the expression of target gene in the in vitro cultured mammalian cells was investigated for antihypertensive therapy in spontaneous hypertensive rat (SHR) at post-transcriptional level. The sense and antisense RNA oligonucleotides strands targeting angiotensin Ⅱ receptor mRNA were synthesized individually according to the sequence of the rat angiotensin Ⅱ receptor. For preparation of duplexes, sense- and antisense-stranded oligonucleotides were mixed and annealed, and the annealed duplexes were cloned into the pGenesil-1 vector. The rat glioma cells were transfected with constructed pGenesil-1-shRNA plasmid and scrambled plasmid. The cultured cells were collected at different phases. RT-PCR and Western blot were performed. The AT1 mRNA and protein levels behaved ultimately same. Compared to control after 48 h, AT1 mRNA levels were decreased to 35.5%±3.0 %, and the levels reached their lowest point after 72 h (20.7% ±4 % of control). At 24 and 48 h, AT1 protein was reduced to 46.9%±4.2% and 36.98%±3.7% respectively compared to control and a maximum reduction was observed after 72 h of incubation (28.1%± 4% compared to controls). Plasmid-based shRNA expression systems targeted against the rat angiotensin Ⅱ receptor gene were generated successfully. The shRNAs with a 22-nt stem and a short loop were cleaved into small interfering dsRNA (siRNA) by the Dicer. The in vitro transcribed siRNA enables the effective silencing of gene expression to the target mRNA and leads to effective inhibition of translation of proteins and will be lay the foundation of application of gene silencing technology to hypertensive rats.
基金supported by the National Natural Science Founds for Distinguished Young Scholar of China (No. 30725040)
文摘The expression of angiotensin Ⅱ type 1 receptor (AT1R) and angiotensin Ⅱ type 2 receptor (AT2R) in aldosterone-producing adenoma (APA) of the adrenal gland was detected, and their relationship with clinical indexes of APA was analyzed. The mRNA expression of AT1R and AT2R in 50 cases of APA and tissues adjacent to tumors and 12 cases of normal adrenal tissues was detected by using reverse transcriptase polymerase chain reaction (RT-PCR). The expression of AT1R and AT2R proteins in paraffin-embedded slices of tissue was detected by immunohistochemistry. The expression of AT1R in adenoma, tissues adjacent to tumor, and normal tissues of the adrenal gland showed no significant differences. The expression of AT2R in APA tissue was lower than that in normal adrenal gland tissues (P<0.05). Correlation analysis of the mRNA expression level of AT2R and clinical data from patients demonstrated that AT2R expression was negatively related to plasma aldosterone concentration (PAC) (r=-0.467, P<0.05), but positively related with plasma renin activity (PRA) (r=0.604, P<0.05). It is concluded that down-regulation of the AT2R expression is possibly related with the tumorigenesis of APA.
基金Supported by Biomedical Research Institute Grant(PNU-2013-0373),Pusan National University Hospital
文摘AIM: To investigate the effect of angiotensin II type 1 receptor blocker (ARB) and angiotensin converting enzyme inhibitor (ACEI) on intraocular growth factors and their receptors in streptozotocin-induced diabetic rats. METHODS: Forty Sprague-Dawley rats were divided into 4 groups: control, diabetes mellitus (DM), candesartan- treated DM, and enalapril-treated DM (each group, n---10). After the induction of DM by streptozotocin, candesartan [ARB, 5 mg/(kg · d)] and enalapril [ACEI, 10 mg/(kg · d)] were administered to rats orally for 4Wko Vascular endothelial growth factor (VEGF) and angiotensin II (Ang II) concentrations in the vitreous were measured using enzyme-linked immunosorbent assays, and VEGF receptor 2 and angiotensin II type 1 receptor (ATIR) levels were assessed at week 4 by Western blotting. RESULTS: Vitreous Ang II levels were significantly higher in the DM group and candesartan-treated DM group than in the control (P=0.04 and 0.005, respectively). Vitreous ATIR increased significantly in DM compared to the other three groups (P〈0.007). Candesartan-treated DM rats showed higher vitreal ATIR concentration than the enalapril-treated DM group and control (P〈0.001 and P=0.005, respectively). No difference in vitreous Ang II and ATIR concentration was found between the enalapril- treated DM group and control. VEGF and its receptor were below the minimum detection limit in all 4 groups. CONCLUSION: Increased Ang II and ATIR in the hyperglycemic state indicate activated the intraocular renin-angiotensin system, which is inhibited more effectively by systemic ACEI than systemic ARB.
基金supported by the Science Foundation of Zhuhai Municipality (PC20052031)
文摘Objective: To investigate the effect of activation of angiotensin Ⅱ(AngⅡ) type 1 (AT1) receptors in the median preoptic nucleus (MnPO) of rats on renal sodium excretion. Methods: After anesthesia, the rats were injected into the MnPO via an implanted cannula. Urine samples were collected via a bladder cannula, and the urine sodium concentration was assayed with flame spectrophotometry. The serum level of endogenous digitalis-like factor (EDLF) and Na^+,K^+-ATPase activity in the renal cortex tissue were assayed respectively with a radioimmunoassay and with an ammonium molybdophosphate-based kit. Results: Both the urinary volume and the sodium excretion peaked 60 min after AngⅡ was administered into the MnPO. The responses were accompanied by an increase in serum EDLF and a decrease in Na^+,K^+-ATPase activity in the renal cortex. The responses of diuresis and natriuresis, as well as an increase in serum EDLF and a decrease in Na^+,K^+-ATPase activity in the renal cortex induced by MnPO adminstration with AngⅡ were inhibited by pior treatment with the AngⅡ receptor blocking agent losartan into the MnPO. Conclusion: These results suggest that activation of AT1 receptors in the MnPO of rat induces diuretic and natriuretic responses. The responses are associated with an increase release of EDLF and with the inhibition of Na^+,K^+-ATPase activity in renal cortex tissue.
基金This project was financially aided by the National"Seven-Five"Research Funds of China
文摘The expression of the products of IGF-Ⅱ,IGF-Ⅱ receptors(IGF-Ⅱ-R)and CSF-Ⅰ re-ceptors(CSF-Ⅰ-R)was observed in 17 cases of human primary hepatocellular carcinoma(PHC)and the juxtacancerous liver tissue with immunohistochemistry(ABC),Western blot and North-ern blot technique,It was found that the expression of IGF-Ⅱ,IGF-Ⅱ-R and CSF-Ⅰ-R was signif-icantly higher in PHC than in normal liver tissue and the expression of IGF-Ⅱ and IGF-Ⅱ-R wasremarkably higher in the juxtacancerous liver tissue from PHC patients than in PHC proper.Itwas noteworthy that the expression of IGF-Ⅱ in both the cancer proper and the juxtacancerousliver tissue was characterized by its fetal type.Besides,the expression of CSF-Ⅰ-R was signifi-cantly higher in PHC than in the juxtacancerous liver tissue.It is believed that the abnormal ex-pression of IGF-Ⅱ,IGF-Ⅱ-R and CSF-I-R in PHC and the juxtacaneerous liver tissue might berelated to the autocrine mechanism of human PHC.
文摘The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was considered a zoonotic disease, the virus has also spread among humans via respiratory secretions. The expression and distribution of angiotensin converting enzyme type 2(ACE2) in various human organs might also show other possible infection routes. High ACE2 ribonucleic acid expression has been identified in the gastrointestinal tract(GI) indicating its importance as a possible infection pathway of SARS-CoV-2. ACE2 induces viral entry into the host and most importantly has been found to be associated with the function of the gut. Its deficiency has been implicated in several pathologies such as colorectal inflammation. The renin-angiotensin system(RAS) is an essential regulatory cascade operating both at a local tissue level and at the systemic or circulatory level. The RAS may be important in the pathogenesis of chronic liver disease and is associated with the up-regulation of ACE2. Thus, the aim of this review is firstly, the analysis of some important general and genome characteristics of SARS-CoV-2 and secondly, and most importantly, to focus on the utility of ACE2 receptors in both SARS-CoV-2 replication and pathogenesis, especially in the GI tract.
文摘Regulation of the number of aetivin receptors that are present in the cell membrane plays a key role in the modulation of cellular responses to activin. In order to find the regulators, a novel protein ARIPzip, interacting with activin type II receptors, was searched and identified by using yeast two-hybrid screening. ARIPzip is a splicing variant of ARIP2. This has been discussed previously. ARIPzip can specifically interact with ActR Ⅱ A, and is widely distributed in mouse tissues. Overexpression of ARIPzip can cause the activin-induced transcriptional activities to increase in a dose-dependent manner while the overexpression of ARIV2 can decrease these activities. These data suggest that the C-terminal rezions of ARIP2 and ARIPzip are involved in the regulation of activin signaling.
文摘Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes(α, β, γ, and δ). The genes undergo transactivation or transrepression under specific mechanisms that lead to the induction or repression of target gene expression. As is the case with other nuclear receptors, all four PPAR isoforms contain five or six structural regions in four functional domains; namely, A/B, C, D, and E/F. PPARs have many functions, particularly functions involving control of vascular tone, inflammation, and energy homeostasis, and are, therefore, important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. Hence, PPARs also represent drug targets, and PPARα and PPARγ agonists are used clinically in the treatment of dyslipidemia and type 2 diabetes mellitus, respectively. Because of their pleiotropic effects, they have been identified as active in a number of diseases and are targets for the development of a broad range of therapies for a variety of diseases. It is likely that the range of PPARγ agonist therapeutic actions will result in novel approaches to lifestyle and other diseases. The combination of PPARs with reagents or with other cardiovascular drugs, such as diuretics and angiotensin Ⅱ receptor blockers, should be studied.This article provides a review of PPAR isoform characteristics, a discussion of progress in our understanding of the biological actions of PPARs, and a summary of PPAR agonist development for patient management. We also include a summary of the experimental and clinical evidence obtained from animal studies and clinical trials conducted to evaluate the usefulness and effectiveness of PPAR agonists in the treatment of lifestyle-related diseases.
基金Chongqing Science and Health Joint Medical ResearchProject,Grant/AwardNumber:2024MSXM124。
文摘Cerebral ischemia-reperfusion(I/R)injury is a crucial factor that impacts the prognosis of recanalization therapy for acute ischemic stroke(AIS).It has been found that the brain renin-angiotensin system,especially the angiotensinⅡtype 1 receptor(AT1R)pathway,plays a significant role in cerebral I/R injury.This pathway is involved in processes such as oxidative stress,neuroinflammation,apoptosis,and it affects cerebrovascular autoregulation and the maintenance of blood-brain barrier.AT1R blocker(ARB),widely used as an antihypertensive agent,has demonstrated stroke prevention capabilities in numerous prospective studies,independent of its antihypertensive characteristics.Studies focusing on neurological diseases like Alzheimer's disease,Parkinson's disease,and cognitive impairment have confirmed that ARBs exhibit neuroprotective effects and aid in improving neurological functions.Preclinical studies have shown that ARBs can reduce infarct volume and brain edema,inhibit multiple signaling pathways associated with I/R injury,restore energy levels in damaged brain regions,and rescue the penumbra by promoting neovascularization in cerebral I/R models.These findings suggest that ARBs have potential to become a novel category of neuroprotecting agents for clinical treatment of Als.Therefore,this review primarily provides a theoretical foundation and practical evidence for the future clinical utilization of ARBs as neuroprotective agents following reperfusion therapy for Als.It outlines the role of cerebral I/R injury through the AT1R pathway and highlights the research progressmadeonARBs in I/Rmodels.
基金supported by grants from the National Key Research and Development Project(2020YFA0803800 to JL,2018YFE0113500 to JX)National Natural Science Foundation of China(82020108002 and 81911540486 to JX)+2 种基金Innovation Program of Shanghai Municipal Education Commission(2017-01-07-00-09-E00042 to JX)Science and Technology Commission of Shanghai Municipality(20DZ2255400 and 18410722200 to JX)the“Dawn”Program of the Shanghai Education Commission(19SG34 to JX).
文摘Background:Exercise is beneficial for muscle atrophy.Peroxisome proliferator-activated receptor gamma(PPARγ) and microRNA-29 b(miR-29 b) have been reported to be responsible for angiotensinⅡ(AngⅡ)-induced muscle atrophy.However,it is unclear whether exercise can protect AngⅡ-induced muscle atrophy by targeting PPARγ/miR-29 b.Methods:Skeletal muscle atrophy in both the control group and the run group was established by AngⅡ infusion;after 1 week of exercise training,the mice were sacrificed,and muscle weight was determined.Myofiber size was measured by hematoxylin-eosin and wheat-germ agglutinin staining.Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling staining.The expression level of muscle atrogenes,including F-box only protein 32(FBXO32,also called Atrogin-1) and muscle-specific RING-finger 1(MuRF-1),the phosphorylation level of protein kinase B(PKB,also called AKT)/forkhead box 03 A(FOX03 A)/mammalian target of rapamycin(mTOR) pathway proteins,the expression level of PPARγ and apoptosis-related proteins,including B-cell lymphoma-2(Bcl-2),Bcl-2-associated X(Bax),cysteine-aspartic acid protease 3(caspase-3),and cleaved-caspase-3,were determined by western blot.The expression level of miR-29 b was checked by reversetranscription quantitative polymerase chain reaction.A PPARγ inhibitor(T0070907) or adeno-associated virus serotype-8(AAV8)-mediated miR-29 b overexpression was used to demonstrate whether PPARγ activation or miR-29 b inhibition mediates the beneficial effects of exercise in AngⅡ-induced muscle atrophy.Results:Exercise can significantly attenuate AngⅡ-induced muscle atrophy,which is demonstrated by increased skeletal muscle weight,cross-sectional area of myofiber,and activation of AKT/mTOR signaling and by decreased atrogenes expressions and apoptosis.In AngⅡ-induced muscle atrophy mice models,PPARγ was elevated whereas miR-29 b was decreased by exercise.The protective effects of exercise in AngⅡ-induced muscle atrophy were inhibited by a PPARγ inhibitor(T0070907) or adeno-associated virus serotype-8(AAV8)-mediated miR-29 b overexpression.Conclusion:Exercise attenuates AngⅡ-induced muscle atrophy by activation of PPARγ and suppression of miR-29 b.
基金The project supported by National Natural Science Foundation of China(81102444)the Major Scientific and Technological Special Project for"Significant New Drugs Creation"(2009ZX09302-003,2013ZX09508104)the Central Public Scientific Research Institution Fundamental Project(2014CX05)
文摘OBJECTIVE To investigate the vasorelaxant effect of pinocembrin(5,7-dihydroxyflavanone),one of the main flavonoids in propolis,on angiotensinⅡ(AngⅡ)induced vasoconstriction and the molecular mechanism of action.METHODS The isometric vascular tone was measured in thoracic aortic rings from SD rat,and the effects of pinocembrin on the single dose and concentration cumulative response curves of AngⅡ were recorded.The binding of pinocembrin to the angiotensin type 1 receptor(AT1R)was studied by using molecule docking analysis.Intracellular[Ca2+]([Ca2+]i)was measured with Fura2/AM in VSMCs.The phosphorylation levels of myosin light chain 2(MLC2)and myosin phosphatase target unit 1(MYPT1),and protein level of Rho kinase 1(ROCK1)in the rat aortic rings were detected by Western blotting.RESULTS Pinocembrin was observed to inhibit AngⅡ-induced vasoconstriction in rat aortic rings with either intact or denuded endothelium.In endothelium-denuded tissues,pinocembrin(pD′2 4.28±0.15)counteracted the contractions evoked by cumulative concentrations of AngⅡ.In a docking model,pinocembrin showed effective binding at the active site of AT1R.Pinocembrin was shown to inhibit both AngⅡ-induced Ca2+ release from internal stores and Ca2+ influx.Moreover,the increase in the phosphorylation of MLC2 and MYPT1,and the increased protein level of ROCK1 induced by AngⅡ was blocked by pinocembrin.CONCLUSION Pinocembrin inhibits AngⅡ-induced rat aortic ring contraction in a Ca2+-dependent and Ca2+-independent manner via blocking AT1R.
文摘Background Angiotensin Ⅱ type 1 receptor (ATR1) / Angiotensin Ⅱ type 2 receptor (ATR2) usually interact with each other in their expression and physiological functions, and nitric oxide (NO) is always involved in ATR1 / ATR2 regulation in vivo. Endothelial cells play a crucial role in the maintenance of vascular function and in the prevention of cardiovascular diseases. Objectives To investigate the effects of angiotensin Ⅱ (Ang Ⅱ) and ATR1 blocker valsartan on ATR1, ATR2 expression and their relation with endothelial nitric oxide synthase (eNOS) expression, and NO production in cultured vascular endothelial cells. Methods Human umbilical vein endothelial cell line (HUVEC) and bovine aortic endothelial cell (BAEC) were used. BAEC were isolated from aorta of newborn calf by enzyme digestion and cells of 3-5 passages were used. Cells were incubated with vehicle, Ang Ⅱ, valsartan, or Ang Ⅱ plus valsartan respectively for various periods. ATR1, ATR2, eNOS expression and NO production were detected. Results Incubation with AngⅡ or valsartan apparently downregulated ATR1 mRNA and protein expression in vascular endothelial cells, and the combination effect of the two drugs were more apparent. Ang Ⅱ showed a transient slightly promotive effect on eNOS and NO generation in BAEC and an apparently inhibitory effect with prolonged incubation, while valsartan can apparently reverse those effects. Conclusions Both Ang Ⅱ and valsartan downregulated the expression of ATR1 in vascular endothelial cells. The synergistic effect of the two drugs was more apparent. Prolonged incubation with Ang Ⅱ can apparently inhibit eNOS expression and NO production in endothelial cells, while valsartan can apparently reverse that inhibitory effect.
基金supported by Science and Technology Bureau of Qingdao City (Grant No. 02-2-kj-yn-25)
文摘Background It's established that Angiotensin Ⅱ and its receptors are involved in intimal hyperplasia after balloon injury and stent restenosis. Recent evidence also suggests that statins have some anti-intimal hyperplasia effects. In this study, the effect of Rosuvastatin on expression of angiotensin Ⅱ receptors in rat aortic endothelium after balloon injury is therefore investigated. Methods All 52 Wistar Kyoto rats were established to aorta injury models by 2F balloon catheter, then were randomly divided into sham operation group, aorta injury group and Rosuvastatin-treatment group. After 14 days, the aortic specimens of the animals were harvested and performed immunohistochemistry and determination of molecular biology. Results The results showed that (i) The 14 days-balloon injury induced obvious intima thickening (P 〈 0.01), however, the phenomenon was reduced by 14 daystreatment with Rosuvastatin (P 〈 0.01). (ii) The expressions of angiotention Ⅱ type Ⅰ (AT1) and type Ⅱ (AT2) receptor mRNA and protein were markedly up-regulated by the balloon injury (P 〈 0.01), after 14 days-treatment with Rosuvastatin, the expression of AT1 receptor mRNA and its protein was decreased (P 〈 0.01), but the expression of AT2 receptor mRNA and its protein was further increased (P 〈 0.05). Conclusion In this study, we observed that the balloon injury induced-intima thickening was reduced by Rosuvastatin in rats, which might be linked with the regulation of expression of angiotensin Ⅱ receptors.
文摘Background Many studies have suggested that angiotensin Ⅱ (Ang Ⅱ) and its receptors may be involved in the development of asthma. However, the expression of angiotensin Ⅱ receptors (AGTR) is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma. Methods Rats were sensitized with ovalbumin (OVA) for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan (15, 30, 50 mg.kg-1.d-1) or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting. Results AGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats (50 mg.kg-1.d-1) were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-β1 and PDGF in BALE Conclusions AGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma. Ang Ⅱ and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats. Valsartan, a AGTR1 antagonist, could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats.
文摘To explore the relation of angiotensin-converting enzyme (ACE) and angiotensin Ⅱ type 1 receptor (AT1R) gene polymorphism with coronary heart disease (CHD) and the severity of coronary artery stenosis, 130 CHD patients who underwent coronary angiography were examined for the number of affected coronary vessels (≥75% stenosis) and coronary Jeopardy score. The insertion/deletion of ACE gene polymorphism and AT1R gene polymorphism (an A→C transversion at nucleotide position 1166) were detected by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) in CHD patients and 90 healthy serving as controls. The resuits showed that DD genotype and of ACE were more frequent in CHD patients than that in control group (38.5% vs 14.4%, P〈0.001). The frequency of the ATIR A/C genotypes did not differ between the patients and the controls (10% vs 13.1%, P〉0.05). The relative risk associated with the ACE-DD was increased by AT1R-AC genotype. Neither the number of affected coronary vessels nor the coronary score differed among the ACE I/D genotypes (P〉0.05). But the number of affected coronary vessels and the coronary score were significantly greater in the patients with the AT1R-AC genotype than in those with the AA genotype (P〈0.05). In conclusion, DD genotype may be risk factor for CHD and MI in Chinese people, and is not responsible for the development of the coronary artery stenosis. The AT1R-C allele may increase the relative risk associated with the ACE-DD genotype, and may be involved in the development of the stenosis of coronary artery.
基金Supported by grants from the Science and Technology Department of Sichuan Province,No.2011SZ0094
文摘AIM: To investigate the roles of nuclear factor(NF)-κB and angiotensin Ⅱ receptor type 1(AT1R) in the pathogenesis of non-alcoholic fatty liver disease(NAFLD).METHODS: Forty-two healthy adult male SpragueDawley rats were randomly divided into three groups:the control group(normal diet), the model group,and the intervention group(10 wk of a high-fat diet feeding, followed by an intraperitoneal injection of PDTC); 6 rats in each group were sacrificed at 6, 10,and 14 wk. After sacrifice, liver tissue was taken,paraffin sections of liver tissue specimens were prepared, hematoxylin and eosin(HE) staining was performed, and pathological changes in liver tissue(i.e., liver fibrosis) were observed by light microscopy.NF-κB expression in liver tissue was detected by immunohistochemistry, and the expression of AT1 R in the liver tissue was detected by reverse transcriptionpolymerase chain reaction(RT-PCR). The data are expressed as mean ± SD. A two-sample t test was used to compare the control group and the model group at different time points, paired t tests were used to compare the differences between the intervention group and the model group, and analysis of variance was used to compare the model group with the control group. Homogeneity of variance was analyzed with single factor analysis of variance. H variance analysis was used to compare the variance. P < 0.05 wasconsidered statistically significant.RESULTS: The NAFLD model was successful after 6wk and 10 wk. Liver fibrosis was found in four rats in the model group, but in only one rat in the intervention group at 14 wk. Liver steatosis, inflammation, and fibrosis were gradually increased throughout the model. In the intervention group, the body mass,rat liver index, serum lipid, and transaminase levels were not increased compared to the model group.In the model group, the degree of liver steatosis was increased at 6, 10, and 14 wk, and was significantly higher than in the control group(P < 0.01). In the model group, different degrees of liver cell necrosis were visible and small leaves, punctated inflammation,focal necrosis, and obvious ballooning degeneration were observed. Partial necrosis and confluent necrosis were observed. In the model group, liver inflammatory activity scores at 6, 10, and 14 wk were higher than in the control group(P < 0.01). Active inflammation in liver tissue in the intervention group was lower than in the model group(P < 0.05). HE staining showed liver fibrosis only at 14 wk in 4/6 rats in the model group and in 1/6 rats in the intervention group. NF-κB positive cells were stained yellow or ensemble yellow,and NF-κB was localized in the cytoplasm and/or nucleus. The model group showed NF-κB activation at6, 10, and 14 wk in liver cells; at the same time points,there were statistically significant differences in the control group(P < 0.01). Over time, NF-κB expression increased; this was statistically lower(P < 0.05) at14 weeks in the intervention group compared to the model group, but significantly increased(P < 0.05)compared with the control group; RT-PCR showed that AT1 R mRNA expression increased gradually in the model group; at 14 wk, the expression was significantly different compared with expression at 10 weeks as well as at 6 weeks(P < 0.05). In the model group, AT1 R mRNA expression was significantly higher than at the same time point in the control group(P <0.01).CONCLUSION: With increasing severity of NAFLD,NF-κB activity is enhanced, and the inhibition of NF-κB activity may reduce AT1 R mRNA expression in NAFLD.