OBJECTIVE: To explore the effect of telmisartan on the expression of metadherin in the kidney of mice with unilateral ureter obstruction. METHODS: Eighteen male C57 mice were randomized into sham-operated group, model group and telmisartan treatment group. In the latter two groups, renal interstitial fibrosis as the result of unilateral ureter obstruction (UUO) was induced by unilateral ureteral ligation with or without telmisartan intervention. Renal pathological changes of the mice were assessed using Masson staining, and immunohistochemistry and Western blotting were used to detect the expression of extracellular matrix proteins and metadherin in the kidney of the mice. In the experiment, cultured mouse renal tubular epithelial cells (mTECs) were stimulated with transforming growth factor-β1 (TGF-β1) and transfected with a siRNA targeting metadherin, and the changes in the expressions of extracellular matrix proteins and metadherin were detected using Western blotting. RESULTS: The expressions of extracellular matrix proteins and metadherin increased significantly in the kidney of mice with UUO ( < 0.05). Intervention with telmisartan significantly lowered the expressions of extracellular matrix proteins and metadherin and alleviated the pathology of renal fibrosis in mice with UUO ( < 0.05). In cultured mTECs, siRNA-mediated knockdown of metadherin obviously reversed TGF-β1-induced increase in the expressions of extracellular matrix proteins and metadherin. CONCLUSIONS Telmisartan can suppress the production of extracellular matrix proteins and the expression of metadhein to attenuate UUO-induced renal fibrosis in mice.
Angiotensin II Type 1 Receptor Blockers ; Animals ; Antihypertensive Agents ; Extracellular Matrix Proteins ; metabolism ; Fibrosis ; Kidney ; drug effects ; metabolism ; pathology ; Male ; Membrane Proteins ; genetics ; metabolism ; Mice ; Mice, Inbred C57BL ; RNA, Small Interfering ; Random Allocation ; Telmisartan ; pharmacology ; Transforming Growth Factor beta1 ; pharmacology ; Ureteral Obstruction ; complications ; metabolism

This study aimed to investigate the functional and morphological changes in the corpus cavernosum after cavernous nerve (CN) injury or neurectomy and then reveal whether treatment with the angiotensin II Type 1 receptor antagonist losartan would improve erectile function as well as its potential mechanisms. A total of 48 10-week-old Sprague-Dawley male rats, weighing 300-350 g, were randomly divided into the following four groups (n = 12 per group): sham operation (Sham) group, bilateral cavernous nerve injury (BCNI) group, losartan-treated BCNI (BCNI + Losartan) group, and bilateral cavernous neurectomy (Neurectomy) group. Losartan was administered once daily by oral gavage at a dose of 30 mg kg^-1 day^-1 for 4 weeks starting on the day of surgery. The BCNI and the Neurectomy groups exhibited decreases in erectile response and increases in apoptosis and oxidative stress, compared with the Sham group. Treatment with losartan could have a modest effect on erectile function and significantly prevent corporal apoptosis and oxidative stress. The phospho-B-cell lymphoma 2 (Bcl-2)-associated death promoter (p-Bad)/Bad and phospho-the protein kinase B (p-AKT)/AKT ratios were substantially lower, while the Bcl-2-associated X protein (Bax)/Bcl-2 ratio, nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap-1), transforming growth factor-β 1 (TGF-β 1) and heme oxygenase-1 (HO-1) levels, and caspase-3 activity were higher in the BCNI and Neurectomy groups than in the Sham group. After 4 weeks of daily administration with losartan, these expression levels were remarkably attenuated compared with the BCNI group. Taken together, our results suggested that early administration of losartan after CN injury could slightly improve erectile function and significantly reduce corporal apoptosis and oxidative stress by inhibiting the Akt/Bad/Bax/caspase-3 and Nrf2/Keap-1 pathways.
Angiotensin II Type 1 Receptor Blockers/pharmacology* ; Animals ; Apoptosis/drug effects* ; Denervation ; Disease Models, Animal ; Erectile Dysfunction/metabolism* ; Losartan/pharmacology* ; Male ; Oxidative Stress/drug effects* ; Penile Erection/drug effects* ; Penis/metabolism* ; Rats ; Rats, Sprague-Dawley

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.
Angiotensin II ; pharmacology ; Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Animals, Newborn ; Catalase ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Cells, Cultured ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Fibroblasts ; Gene Expression Regulation ; drug effects ; Heart ; drug effects ; Hydrogen Peroxide ; metabolism ; pharmacology ; Isoflavones ; pharmacology ; Mice ; Myocardium ; cytology ; enzymology ; metabolism ; NADPH Oxidases ; antagonists & inhibitors ; metabolism ; Neuropeptides ; metabolism ; Signal Transduction ; drug effects ; Transcription Factor AP-1 ; antagonists & inhibitors ; metabolism ; Transcriptional Activation ; drug effects ; rac1 GTP-Binding Protein ; metabolism

BACKGROUND/AIMS: We investigated whether angiotensin III (Ang III) is involved in monocyte recruitment through regulation of the chemokine monocyte chemoattractant protein-1 (MCP-1) in cultured human proximal tubular epithelial cells (HK-2 cells). METHODS: We measured MCP-1 levels in HK-2 cells that had been treated with various concentrations of Ang III and Ang II type-1 (AT1) receptor antagonists at various time points. The phosphorylation states of p38, c-Jun N-terminal kinases (JNK), and extracellular-signal-regulated kinases were measured in Ang III-treated cells to explore the mitogen-activated protein kinase (MAPK) pathway. MCP-1 levels in HK-2 cell-conditioned media were measured after pre-treatment with the transcription factor inhibitors curcumin or pyrrolidine dithiocarbamate. RESULTS: Ang III increased MCP-1 protein production in dose- and time-dependent manners in HK-2 cells, which was inhibited by the AT1 receptor blocker losartan. p38 MAPK activity increased significantly in HK-2 cells exposed to Ang III for 30 minutes, and was sustained at higher levels after 60 minutes (p < 0.05). Total phosphorylated JNK protein levels tended to increase 20 minutes after stimulation with Ang III. Pre-treatment with a p38 inhibitor, a JNK inhibitor, or curcumin significantly inhibited Ang III-induced MCP-1 production. CONCLUSIONS: Ang III increases MCP-1 synthesis via stimulation of intracellular p38 and JNK MAPK signaling activity and subsequent activated protein-1 transcriptional activity in HK-2 cells.
Angiotensin II Type 1 Receptor Blockers/pharmacology ; Angiotensin III/*pharmacology ; Cell Line ; Chemokine CCL2/*metabolism ; Dose-Response Relationship, Drug ; Epithelial Cells/*drug effects/metabolism ; Humans ; JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism ; Kidney Tubules, Proximal/*drug effects/metabolism ; Phosphorylation ; Protein Kinase Inhibitors/pharmacology ; Signal Transduction/drug effects ; Time Factors ; Transcription Factor AP-1/metabolism ; Up-Regulation ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism

Angiotensin II (Ang II) induces the pathological process of vascular structures, including renal glomeruli by hemodynamic and nonhemodynamic direct effects. In kidneys, Ang II plays an important role in the development of proteinuria by the modification of podocyte molecules. We have previously found that Ang II suppressed podocyte AMP-activated protein kinase (AMPK) via Ang II type 1 receptor and MAPK signaling pathway. In the present study, we investigated the roles of AMPK on the changes of p130Cas of podocyte by Ang II. We cultured mouse podocytes and treated them with various concentrations of Ang II and AMPK-modulating agents and analyzed the changes of p130Cas by confocal imaging and western blotting. In immunofluorescence study, Ang II decreased the intensity of p130Cas and changed its localization from peripheral cytoplasm into peri-nuclear areas in a concentrated pattern in podocytes. Ang II also reduced the amount of p130Cas in time and dose-sensitive manners. AMPK activators, metformin and AICAR, restored the suppressed and mal-localized p130Cas significantly, whereas, compound C, an AMPK inhibitor, further aggravated the changes of p130Cas. Losartan, an Ang II type 1 receptor antagonist, recovered the abnormal changes of p130Cas suppressed by Ang II. These results suggest that Ang II induces the relocalization and suppression of podocyte p130Cas by the suppression of AMPK via Ang II type 1 receptor, which would contribute to Ang II-induced podocyte injury.
AMP-Activated Protein Kinases/antagonists & inhibitors/chemistry/*metabolism ; Aminoimidazole Carboxamide/analogs & derivatives/pharmacology ; Angiotensin II/*pharmacology ; Angiotensin II Type 1 Receptor Blockers/pharmacology ; Animals ; Blotting, Western ; Cell Line ; Cell Nucleus/metabolism ; Crk-Associated Substrate Protein/*metabolism ; Cytoplasm/metabolism ; Focal Adhesion Kinase 1/metabolism ; Losartan/pharmacology ; Metformin/pharmacology ; Mice ; Microscopy, Confocal ; Podocytes/cytology/drug effects/metabolism ; Protein Kinase Inhibitors/*pharmacology ; Ribonucleotides/pharmacology ; Signal Transduction/*drug effects

OBJECTIVETo investigate the effects of angiotensin II type 1 receptor (AT1R) knockdown on the first-phase insulin secretion in isolated islets of db/db mice and explore the possible mechanisms.

METHODSIslets were isolated from db/db and db/m mice and the expression level of AT1R in the islets was assayed. A recombinant adenovirus containing siRNA targeting AT1R (Ad-siAT1R) and a recombinant adenovirus with nonspecific siRNA (Ad-siControl) were constructed to infect the isolated islets for 72 h. AT1R, GLUT-2, and GCK expressions in the islets were investigated and islet perifusion was performed to evaluate the kinetics of insulin release.

RESULTSThe expression level of AT1R in the isolated islets from db/db mice was twice that of islets from db/m mice. The islets treated with Ad-siAT1R showed significantly decreased AT1R mRNA and protein levels and significantly increased expression of GLUT-2 (by 190%) and GCK (by 121%) compared to those treated with Ad-siControl (P<0.05). In response to stimulation with 16.7 mmol/L glucose, the first-phase insulin secretion was impaired in both Ad-siControl group and mock infected group with the peak insulin levels only 1.8 times of the basal level; the first-phase insulin secretion was markedly improved in islets treated with Ad-siAT1R, with a peak insulin level reaching 2.8 times of the basal level.

CONCLUSIONSIn isolated islets of db/db mice, selective AT1R inhibition can restore the first phase insulin secretion by up-regulating GLUT-2 and GCK, which may be one of the potential mechanisms by which AT1R blockers improve insulin secretion function.

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Diabetes Mellitus, Experimental ; Gene Knockdown Techniques ; Glucose ; Glucose Transporter Type 2 ; metabolism ; Insulin ; secretion ; Islets of Langerhans ; metabolism ; Mice ; Protein-Serine-Threonine Kinases ; metabolism ; RNA, Small Interfering ; pharmacology

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Cardiovascular Agents ; pharmacology ; Clinical Trials as Topic ; Heart Failure ; drug therapy ; Humans ; Neprilysin ; antagonists & inhibitors

BACKGROUND/AIMS: Magnesium (Mg) is an essential element for vascular function and blood pressure regulation. Several studies have demonstrated that Mg concentration is inversely associated with blood pressure, and that Mg supplementation attenuates hypertension. The purpose of this study was to evaluate the effect of dietary Mg supplementation on the blood pressure effects of an angiotensin II receptor blocker (ARB) in hypomagnesemic rats. METHODS: Fifty male Sprague-Dawley rats were randomly divided into Mg-deficient (n = 30), normal diet plus Mg (n = 10), and control groups (n = 10). Mg-free, high-Mg, and normal-Mg diets were respectively fed to the rats. After 14 weeks, 10 of the 30 Mg-deficient rats were treated with Mg, 10 Mg-deficient rats received an ARB, and 10 Mg-deficient rats received an ARB plus Mg for 4 weeks. RESULTS: Systolic blood pressure was significantly higher in the Mg-deficient rats than in the control rats at week 14. Hypomagnesemic rats exhibited decreased systolic blood pressure after treatment with Mg, and systolic blood pressure showed a greater decrease after ARB treatment. Treatment with the ARB/Mg combination resulted in the greatest decrease in systolic blood pressure. Mg deficiency did not affect the serum angiotensin II level, but did increase the serum aldosterone concentration. Concomitant Mg/ARB supplementation significantly decreased the elevated serum aldosterone level in hypomagnesemic rats. Kidney tissues of the hypomagnesemic rats revealed mild to moderate inflammatory infiltrates. Mg and/or ARB treatment did not reverse the inflammatory reaction in the kidneys of hypomagnesemic rats. CONCLUSIONS: Concurrent dietary Mg supplementation can enhance ARB-induced blood pressure reduction in rats with hypomagnesemic hypertension.
Aldosterone/blood ; Angiotensin II/blood ; Angiotensin II Type 1 Receptor Blockers/*pharmacology ; Animals ; Antihypertensive Agents/*pharmacology ; Biological Markers/blood ; Blood Pressure/*drug effects ; *Dietary Supplements ; Disease Models, Animal ; Hypertension/blood/*drug therapy/pathology/physiopathology ; Kidney/drug effects/pathology ; Magnesium/blood/*pharmacology ; Magnesium Deficiency/blood/*drug therapy/pathology/physiopathology ; Male ; Rats ; Rats, Sprague-Dawley ; Systole ; Time Factors

OBJECTIVETo investigate the effect of low-dose carvedilol combined with candesartan in the prevention of acute and chronic cardiotoxicity of anthracycline drugs in adjuvant chemotherapy of breast cancer.

METHODSForty patients were randomly divided into two groups: the experimental group with chemotherapy plus low-dose carvedilol combined with candesartan (20 cases) and control group with chemotherapy alone (20 cases). The same chemotherapy was given to the two groups. All the 40 patients had no contraindication for carvedilol and candesartan. Patients of the experimental group received low-dose carvedilol from 2.5 mg orally twice a day at first cycle to 5 mg twice a day gradually if no side reactions, and candesartan 2.5 mg orally once a day. Electrocardiogram, ultrasonic cardiogram, arrhythmia, troponin and non-hematologic toxicity were recorded and compared after the second, forth and sixth cycle of chemotherapy. Each cycle included 21 days.

RESULTSLVEF was decreased along with the prolongation of chemotherapy in the experimental group and control group. LVEDD and LVESD showed no significant changes in the experimental group, but gradually increased in the control group. After four and six cycles of chemotherapy, LVEF were (57.00 ± 5.13)% and (45.95 ± 3.68)%, respectively, in the control group, significantly lower than that of (67.00 ± 5.13)% and (57.50 ± 2.57)%, respectively, in the experimental group (P < 0.05). After six cycles of chemotherapy, LVEDD and LVESD were (50.00 ± 10.48) mm and (35.01 ± 2.99) mm, respectively, in the control group, significantly higher than those before chemotherapy (P < 0.05) and experimental group (P < 0.001). The rate of ST segment and T wave abnormalities was 80.0% in the control group after six cycles of chemotherapy, significantly higher than that of 25.0% after four cycles of chemotherapy (P = 0.001) and 10.0% after two cycles of chemotherapy (P < 0.001). The reduction of QRS voltage, arrhythmia and abnormal troponin were 55.0%, 45.0% and 45.0%, respectively, in the control group, significantly higher than those in the experimental group (20.0%, P < 0.05), (10.0%, P = 0.010) and (10.0%, P < 0.05), respectively. The rate of abnormal expression of troponin was 45.0% in the control group, significantly higher than the 10.0% in the experimental group (P < 0.05).

CONCLUSIONSThe use of low-dose carvedilol combined with candesartan can reduce the acute and chronic cardiotoxicity of anthracycline drugs, and with tolerable toxicities. This may provide a new approach to prevent cardiotoxicity of anthracycline drugs in adjuvant chemotherapy of breast cancer.

Adrenergic beta-Antagonists ; administration & dosage ; pharmacology ; Adult ; Aged ; Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; pharmacology ; Antineoplastic Combined Chemotherapy Protocols ; adverse effects ; therapeutic use ; Arrhythmias, Cardiac ; chemically induced ; Benzimidazoles ; administration & dosage ; pharmacology ; Breast Neoplasms ; drug therapy ; surgery ; Carbazoles ; administration & dosage ; pharmacology ; Chemotherapy, Adjuvant ; Cyclophosphamide ; adverse effects ; therapeutic use ; Electrocardiography ; drug effects ; Epirubicin ; adverse effects ; therapeutic use ; Female ; Fluorouracil ; adverse effects ; therapeutic use ; Humans ; Mastectomy, Radical ; Middle Aged ; Propanolamines ; administration & dosage ; pharmacology ; Stroke Volume ; drug effects ; Tetrazoles ; administration & dosage ; pharmacology ; Troponin ; metabolism

The present study was to determine whether candesartan, an angiotensin II type 1 receptor blocker (ARB), exerts anti-inflammatory effects through inhibiting the toll-like receptor 4 (TLR4) pathway in human renal tubular epithelial cells (HKCs). The experiments were carried on cultured HKCs. By means of flow cytometry, Western blot, RT-PCR and ELISA techniques, the TLR4 protein, angiotensin II type 1 receptor (AT1R) and phosphorylated nuclear factor-kappa B (NF-κB) p65 protein level, mRNA levels of macrophage chemoattractant protein-1 (MCP-1) and regulated upon expression normal T cell expressed and secreted (RANTES), as well as MCP-1 and RANTES protein concentrations in conditioned media were measured. The results showed that lipopolysaccharide (LPS) upregulated the TLR4 protein level in cultured HKCs. Application of LPS increased NF-κB activation and induced release of its downstream inflammatory factors including MCP-1 and RANTES. Candesartan reversed LPS-induced upregulation of TLR4 expression, inhibited NF-κB activation, and reduced MCP-1 and RANTES release. However, knockdown on AT1R by siRNA did not change those previous effects of candesartan. These results suggest that candesartan-induced anti-inflammatory effect may be through a novel pathway, independent of AT1R.
Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Benzimidazoles ; pharmacology ; Cells, Cultured ; Epithelial Cells ; drug effects ; metabolism ; Gene Expression Regulation ; Humans ; Kidney Tubules ; cytology ; Lipopolysaccharides ; NF-kappa B ; metabolism ; RNA, Messenger ; Receptor, Angiotensin, Type 1 ; metabolism ; Signal Transduction ; Tetrazoles ; pharmacology ; Toll-Like Receptor 4 ; metabolism ; Up-Regulation