Construction of shRNA Targeted to the Rat Angiotensin Ⅱ Type 1 Receptors and Its RNAi in Cytoplasma

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.

A Quantitative Study on Vascular Angiotensin Ⅱ Receptors in Rats with Portal Hypertension

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.

Effect of angiotensin Ⅱ type 1 receptor blocker and angiotensin converting enzyme inhibitor on the intraocular growth factors and their receptors in streptozotocin-induced diabetic rats

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.

Expression of Angiotensin Ⅱ Receptors in Aldosterone-producing Adenoma of the Adrenal Gland and Their Clinical Significance

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.

Origin and genomic characteristics of SARS-CoV-2 and its interaction with angiotensin converting enzyme type 2 receptors, focusing on the gastrointestinal tract

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.

Activation of angiotensin Ⅱ type 1 receptors in the median preoptic nucleus induces a diuretic and natriuretic response in rats

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.

Peroxisome proliferator-activated receptors for hypertension

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.

Role of angiotensin Ⅱ and angiotensin Ⅱ receptors in vascular smooth muscle cell migration in vitro

Objective To determine the biotic effects of angiotensin Ⅱ (Ang Ⅱ) on the migration of rat smooth muscle cells (VSMCs) and investigate the mechanisms involved in the development of vascular injury Methods VSMCs isolated from aortic media of Wistar rats and cultured by the modified explant method were adopted In the presence and absence of Ang Ⅱ, the expression of Ang Ⅱ receptor (ATR) and reorganization of the actin cytoskeleton and focal adhesion of VSMCs were studied by an immunocytochemistry technique and fluorocytochemistry technique Migration assays were performed with a modified Boyden's chamber The effects of AT 1R antagonist (CV 11974), AT 2R antagonist (PD123319) on the aforementioned target were studied Results VSMCs migration was stimulated by adding Ang Ⅱ The dynamic reorganization of actin cytoskeleton and focal adhesions may be an important mechanism by which Ang Ⅱ facilitates VSMCs motility The expression of AT 1R in VSMCs could be upregulated initially after treatment with Ang Ⅱ, then decreased gradually The expression of AT 1R was downregulated by AT 1R antagonists The effect of Ang Ⅱ on VSMCs migration was mediated by AT 1R, while AT 2R had no significant effect Conclusions The dynamic reorganization of focal adhesions and the actin cytoskeleton is required for Ang Ⅱ induced VSMCs migration This effect is mediated by AT 1R

Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats

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.

Angiotensin receptor blocker drugs and inhibition of adrenal beta-arrestin-1-dependent aldosterone production: Implications for heart failure therapy

Aldosterone mediates many of the physiological and pathophysiological/cardio-toxic effects of angiotensin II(Ang II). Its synthesis and secretion from the zona glomerulosa cells of the adrenal cortex, elevated in chronic heart failure(HF), is induced by Ang II type 1 receptors(AT1Rs). The AT1R is a G protein-coupled receptor, mainly coupling to Gq/11 proteins. However, it can also signal through β-arrestin-1(βarr1) or-2(βarr2), both of which mediate G protein-independent signaling. Over the past decade, a second, Gq/11 proteinindependent but βarr1-dependent signaling pathway emanating from the adrenocortical AT1R and leading to aldosterone production has become appreciated. Thus, it became apparent that AT1R antagonists that block both pathways equally well are warranted for fully effective aldosterone suppression in HF. This spurred the comparison of all of the currently marketed angiotensin receptor blockers(ARBs, AT1R antagonists or sartans) at blocking activation of the two signaling modes(G protein-, and βarr1-dependent) at the Ang IIactivated AT1R and hence, at suppression of aldosterone in vitro and in vivo. Although all agents are very potent inhibitors of G protein activation at the AT1R, candesartan and valsartan were uncovered to be the most potent ARBs at blocking βarr activation by Ang II and at suppressing aldosterone in vitro and in vivo in post-myocardial infarction HF animals. In contrast, irbesartan and losartan are virtually G protein-"biased" blockers at the human AT1R, with very low efficacy for βarr inhibition and aldosterone suppression. Therefore, candesartan and valsartan(and other, structurally similar compounds) may be the most preferred ARB agents for HF pharmacotherapy, as well as for treatment of other conditions characterized by elevated aldosterone.

MicroRNA-155 mediates endogenous angiotensin II type 1 receptor regulation:implications for innovative type 2 diabetes mellitus management

Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharmacological interventions.MicroRNAs(miRNA),are small,non-coding,one-stranded RNA molecules,that can target and silence around 60%of all human genes through translational repression.MiR-155 is an ancient,evolutionarily well-conserved miRNA,with distinct expression profiles and multifunctionality,and a target repertoire of over 241 genes involved in numerous physiological and pathological processes including hematopoietic lineage differentiation,immunity,inflammation,viral infections,cancer,cardiovascular conditions,and particularly diabetes mellitus.MiR-155 Levels are progressively reduced in aging,obesity,sarcopenia,and T2DM.Thus,the loss of coordinated repression of multiple miR-155 targets acting as negative regulators,such as C/EBPβ,HDAC4,and SOCS1 impacts insulin signaling,deteriorating glucose homeostasis,and causing insulin resistance(IR).Moreover,deranged regulation of the renin angiotensin aldosterone system(RAAS)through loss of Angiotensin II Type 1 receptor downregulation,and negated repression of ETS-1,results in unopposed detrimental Angiotensin II effects,further promoting IR.Finally,loss of BACH1 and SOCS1 repression abolishes cytoprotective,anti-oxidant,anti-apoptotic,and anti-inflam matory cellular pathways,and promotesβ-cell loss.In contrast to RAAS inhibitor treatments that further decrease already reduced miR-155 Levels,strategies to increase an ailing miR-155 production in T2DM,e.g.,the use of metformin,mineralocorticoid receptor blockers(spironolactone,eplerenone,finerenone),and verapamil,alone or in various combinations,represent current treatment options.In the future,direct tissue delivery of miRNA analogs is likely.

Impact of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers on the mortality in sepsis: A meta-analysis

BACKGROUND The effect of angiotensin-converting enzyme inhibitors(ACEIs)or angiotensin receptor blockers(ARBs)on the mortality of patients with sepsis is not well characterized.AIM To elucidate the association between prior ACEI or ARB exposure and mortality in sepsis.METHODS The PubMed,EMBASE,Web of Science,and Cochrane Library databases were searched for all studies of premorbid ACEI or ARB use and sepsis mortality until November 302019.Two reviewers independently assessed,selected,and ab-stracted data from studies reporting ACEIs or ARBs,sepsis,and mortality.The primary extracted data consisted of premorbid ACEI or ARB exposure,mortality,and general patient data.Two reviewers independently assessed the risk of bias and quality of evidence.RESULTS A total of six studies comprising 281238 patients with sepsis,including 49799 cases with premorbid ACEI or ARB exposure were eligible for analysis.Pre-morbid ACEIs or ARBs exposure decreased the 30-d mortality in patients with sepsis.Moreover,the use of ACEIs or ARBs was associated with approximately a 6%decreased risk of 30-d mortality.CONCLUSION The results of this systematic review suggest that ACEI or ARB exposure prior to sepsis may be associated with reduced mortality.Further high-quality cohort studies and molecular mechanism experiments are required to confirm our results.

The Role for AVE0991 (MAS-Receptor Angiotensin II (1-7) Agonist) in Reducing Cisplatin-Induced Acute Kidney Injury on C57BL/6 Mice

Acute Kidney Injury (AKI) is a condition that causes nephrotoxicity in kidney tissues due to cisplatin-induced cancer treatments. Hence, it is proposed in this review that AVE0991 (a MAS-receptor Angiotensin II (1-7) agonist) may reduce cisplatin-induced acute kidney injury by promoting nitric oxide production.

Effect of Angiotensin Receptor-Neprilysin Inhibitor versus Valsartan on Cardiac Status in Patients with Chronic Heart Failure with Reduced Ejection Fraction: A Randomized Clinical Trial in Rangpur Medical College Hospital, Bangladesh

Background: Heart failure with reduced ejection fraction has a significant association with considerable morbidity and mortality, but there is still inadequacy in appropriate treatment to prevent this condition. We observed the effect of angiotensin receptor neprilysin inhibitor (ARNi) with such disorder compared to valsartan. Methods: In this single-blind trial, the patients were enrolled with chronic HF aged on or above 40 years, symptomatic NYHA class II - IV, an elevated NT-proBNP above 400 pg/ml level and a reduced LVEF of 40% or less. The patients were randomly assigned 1:1 to the treatment arms either ARNi (50 mg titrated to 100 mg twice a day) or valsartan (40 mg titrated to 80 mg twice a day) and followed for a median of 88 days. The primary outcome was mode of cardiovascular death and re-hospitalization for heart failure. Changes in the level of NT-proBNP and rate of ejection fraction were also measured. Results: Cardiovascular deaths occurred 4 (8%) in the ARNi treatment arm, while 11 (22%) in the valsartan treatment arm with significant hazard ratio in the ARNi group [Hazard Ratio = 0.37;95% CI: 0.34, 0.64;p = 0.042] during a median of 88 days of follow up period and 2 (4%) of the patients from the ARNi treatment arm were hospitalized due to HF, while in the valsartan treatment arm, 10 (20%) patients were hospitalized due to HF followed by receiving treatment respectively with hazard ratio in the ARNi group [Hazard Ratio = 0.80;95% CI: 0.57, 0.92;p Conclusion: Chronic treatment with the angiotensin receptor neprilysin inhibitor (ARNi) strongly decreases the NT-proBNP as well as morbidity and mortality and increases LVEF in patients with heart failure compared to valsartan.

Association of Polymorphisms in Angiotensin-converting Enzyme and Type 1 Angiotensin Ⅱ Receptor Genes with Coronary Heart Disease and the Severity of Coronary Artery Stenosis

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.

Effects of chronic peripheral pretreatment with an angiotensin II type-1 receptor blocker on apoptosis-related molecules in rats with cerebral ischemia/reperfusion injury

Chronic systemic treatment with blockers of angiotensin II type-1 （AT1） receptors inhibits ischemia-induced apoptosis and reduces ischemic neuronal damage. However, the molecular mechanisms of AT1 receptor blockers in modulating neuronal apoptosis remain poorly understood. Pretreatment with irbesartan significantly suppressed cell apoptosis at 1-7 days following cerebral ischemia/reperfusion, increased levels of brain-derived neurotrophic factor, and elevated the ratios of Bcl-2/Bax and phosphorylated cyclic adenosine monophosphate response element-binding protein （pCREB）/CREB in the ischemic cortex at 1 day after reperfusion, as well as suppressing caspase-3 activation. Cerebral ischemia increased the mRNA expression of AT1 and AT2 receptors in the ischemic cortex, whereas irbesartan blocked this increase in AT1 expression but potentiated the expression of AT2. Therefore, this AT1 receptor blocker was neuroprotective by increasing the ratios of Bcl-2/Bax and pCREB/CREB, increasing brain-derived neurotrophic factor levels, inhibiting caspase-3 activation, and modulating AT receptor expression.

Effect of nuclear factor-κB and angiotensin Ⅱ receptor type 1 on the pathogenesis of rat non-alcoholic fatty liver disease

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.

Effects of angiotensin Ⅱ receptor antagonist, Losartan on the apoptosis, proliferation and migration of the human pancreatic stellate cells

AIM： To investigate the effects of AT, （Type 1 angiotensin Ⅱ receptor） antagonist （Losartan） on the apoptosis, proliferation and migration of the human pancreatic stellate cells （hPSCs）. METHODS： hPSCs were isolated from pancreatic sample of patients with pancreatic carcinoma using radioimmunoassay （RIA） technique to detect the concentration of AngⅡ in culture media and cell homogenate. Immunocytochemistry （ICC） and in situ hybridization （ISH） methods were utilized to test AT1 expression in hPSCs. Effects of Losartan on hPSCs proliferation, apoptosis and migration were investigated using BrdU incorporation, TUNEL, flow cytometry （FCM）, and phase-contrast microscope separately when cells treated with Losartan. Immunofluorescence and Western blot were applied to quantify the expression of type Ⅰ collagen in hPSCs. RESULTS： There exists AT1 expression in hPSCs, while no AngⅡ was detected in culture media and cell homogenate. Losartan induces cell apoptosis in a doseand time-dependent manner （apparently at 10^-5 mol/L）, no pro-proliferative effect was observed in the same condition. Corresponding dosage of Losartan can also alleviate the motion capability and type Ⅰ collagen content of hPSCs compared with AngⅡ treatment and non-treatment control groups. CONCLUSION： These findings suggest that paracrine not autocrine functions of AngⅡ may have effects on hPSCs, which was mediated by AT1 expressed on cells, while Losartan may exert anti-fibrotic effects by inhibiting hPSCs motion and partly by inducing apoptosis.

Spectrofluorimetric method for determination of some angiotensin II receptor antagonists

A simple, rapid, accurate and highly sensitive spectrofluorimetric method has been developed for determination of some angiotensin II receptor antagonists (AIIRA’s), namely Losartan potassium (Los-K), Irbesartan (Irb), Valsartan (Val) and Candesartan cilexetil (Cand) in pure forms as well as in their pharmaceutical dosage forms. All the variables affecting the relative fluorescence intensity (RFI) were studied and optimized. Under the optimum conditions, linear relationships with good correlation coefflcients (0.9982–0.9991) were obtained over the concentration range from 0.006 mg/mL to 1.7 mg/mL. Good accuracy and precision were successfully obtained for the analysis of tablets containing each drug alone or combined with hydrochlorothiazide (HCTZ) without interferences from the co-formulated HCTZ or the additives commonly present in tablets.

Effects of angiotensin-converting enzyme inhibitor and angiotensin Ⅱ receptor blocker on one-year outcomes of patients with atrial fibrillation: insights from a multicenter registry study in China

Objective To evaluate the effect of angiotensin-converting enzyme inhibitor(ACEI)/angiotensin Ⅱ receptor blocker(ARB)therapy on the prognosis of patients with atrial fibrillation(AF).Methods A total of 1,991 AF patients from the AF registry were divided into two groups according to whether they were treated with ACEI/ARB at recruitment.Baseline characteristics were carefully collected and analyzed.Logistic regression was utilized to identify the predictors of ACEI/ARB therapy.The primary endpoint was all-cause mortality,while the secondary endpoints included cardiovascular mortality,stroke and major adverse events(MAEs)during the one-year follow-up period.Univariable and multivariable Cox regression were performed to identify the association between ACEI/ARB therapy and the one-year outcomes.Results In total,759 AF patients(38.1%)were treated with ACEI/ARB.Compared with AF patients without ACEI/ARB therapy,patients treated with ACEI/ARB tended to be older and had a higher rate of permanent AF,hypertension,diabetes mellitus,heart failure(HF),left ventricular ejection fraction(LVEF)<40%,coronary artery disease(CAD),prior myocardial infarction(MI),left ventricular hypertrophy,tobacco use and concomitant medications(all P<0.05).Hypertension,HF,LVEF<40%,CAD,prior MI and tobacco use were determined to be predictors of ACEI/ARB treatment.Multivariable analysis showed that ACEI/ARB therapy was associated with a significantly lower risk of one-year all-cause mortality[hazard ratio(HR)(95%CI):0.682(0.527-0.882),P=0.003],cardiovascular mortality[HR(95%CI):0.713(0.514-0.988),P=0.042]and MAEs[HR(95%CI):0.698(0.568-0.859),P=0.001].The association between ACEI/ARB therapy and reduced mortality was consistent in the subgroup analysis.Conclusions In patients with AF,ACEI/ARB was related to significantly reduced one-year all-cause mortality,cardiovascular mortality and MAEs despite the high burden of cardiovascular comorbidities.