OBJECTIVETo observe the effect of sodium tanshinone II (A) sulfonate (STS) on Ang II -induced atrial fibroblast collagen synthesis and TGF-beta1 activation.

METHODAtrial fibroblasts of neonatal rats were cultured to determine the content of collagen protein. The original synthesis rate determined by the [3H]-proline incorporation method was taken as the index for myocardial fibrosis. The content of active TGF-beta1 and total TGF-beta1 in cell culture supernatants were tested and cultured by ELISA. The expression of thrombospondin-1 (TSP-1) was assessed by using Western blot.

RESULTAng II could significantly increase the content of atrial fibroblast collagen and the collagen synthesis rate, the TSP-1 expression and the concentration of active TGF-beta1, without any obvious change in total TGF-beta1. After the STS treatment, all of the indexes, apart from total TGF-beta1, were obviously down-regulated.

CONCLUSIONSTS could decrease the secretion of Ang II -induced atrial fibroblast collagen and the synthesis rate. Its mechanism is related to the inhibition of TSP-1/TGF-beta1 pathway.

Angiotensin II ; pharmacology ; Animals ; Collagen ; biosynthesis ; Fibroblasts ; cytology ; drug effects ; metabolism ; Gene Expression Regulation ; drug effects ; Heart Atria ; cytology ; Phenanthrenes ; pharmacology ; Rats ; Rats, Wistar ; Signal Transduction ; drug effects ; Thrombospondin 1 ; metabolism ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo observe the effect of angiotensin II (Ang II) on calreticulin (CRT) expression and its association with mitochondrial dysfunction in cardiomyocytes.

METHODSPrimary neonatal rat cardiomyocytes were randomly divided into CRT siRNA group, control siRNA group, control group, Ang II+ CRT siRNA group, Ang II+ control siRNA group and Ang II group. The cell surface area, protein synthesis rate, mitochondrial membrane potential level, enzyme activities, and CRT expression were observed.

RESULTSCompared with those in the control group, the cell surface area and protein synthesis rate were both increased and mitochondrial membrane potential level and enzyme activities decreased in Ang II groups. CRT expression was significantly down-regulated in Ang II+ CRT siRNA group with increased cell surface area, protein synthesis rate, mitochondrial membrane potential level and enzyme activities as compared with those in Ang II+ control siRNA group.

CONCLUSIONAng II up-regulates CRT expression to induce mitochondrial injury, which may be an important mechanism of myocardial hypertrophy.

Angiotensin II ; pharmacology ; Animals ; Calreticulin ; metabolism ; Cardiomegaly ; Cells, Cultured ; Membrane Potential, Mitochondrial ; Mitochondria ; pathology ; Myocytes, Cardiac ; pathology ; Protein Biosynthesis ; RNA, Small Interfering ; Rats

OBJECTIVETo investigate the effect of an anti-fibrotic tetra peptide Ac-SDKP on vascular fibrosis by regulating extracellular regulated protein kinase (ERK1/2) activity through Ang II.

METHODSRat vascular adventitial fibroblasts were cultured in vitro. They were randomly divided into control group, Ang II (10(-6) mmol/L) group, Ang II and Ac-SDKP joint action group, PD98059 group. Type I, III collagen contents in adventitia fibroblasts were measured by RT-PCR and the expressions of matrix metalloproteinases (MMP-2) and transforming growth factor-beta1 (TGF-beta1) were determined by Western blot.

RESULTSAc-SDKP could reduced Ang II-induced expression of type I, III collagen secretion and TGF-beta1 at mRNA,and increase MMP-2 expression, PD98059 could inhibit the above effect.

CONCLUSIONThe results suggested that Ac-SDKP could inhibit the formation and development of vascular fibrosis through blocking ERK1/2 pathway mediated by Ang II. Ac-SDKP therefore served as an antifibrotic factor in vascular fibrosis.

Angiotensin II ; adverse effects ; Animals ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Collagen Type III ; biosynthesis ; Fibroblasts ; cytology ; drug effects ; metabolism ; Flavonoids ; pharmacology ; MAP Kinase Signaling System ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Oligopeptides ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo study the effects of peroxisome proliferator-activated receptor gamma agonists on angiotensin II-induced cellular response in cultured fibroblasts derived from patients with hypertrophic scars, so as to investigate its effects on preventing the formation of hypertrophic scars.

METHODSFibroblasts were freshly isolated from hypertrophic scars and cultured with angiotensin II, rosiglitazone and GW9662 at a certain concentration. Fibroblasts proliferation were assessed via Cell Counting Kit-8; the mRNA and protein expressions of Collagen I and Fibronectin (FN) were determined by quantitative real-time RT-PCR and Western blotting.

RESULTSThe absorbance of CCK-8 and relative expression of Collagen I, FN mRNA and protein were 1.082 5 +/- 0.007, 6.45 +/- 0.97, 4.92 +/- 0.86, 2.92 +/- 0.41, 2.78 +/- 1.04 in Ang II group; 0.722 4 +/- 0.012, 1.82 +/- 0.34, 1.78 +/- 0.27, 1.57 +/- 0.46, 1.68 +/- 0.39 in Ros + Ang II group; 0.554 7 +/- 0.012, 0.97 +/- 0.12, 1.07 +/- 1.08, 1.05 +/- 0.43, 1.14 +/- 0.36 in Ros group; 1.056 0 +/- 0.005, 5.83 +/- 0.24, 4.47 +/- 0.32, 2.69 +/- 0.35, 2.62 +/- 0.27 in GW9662 + ros + Ang II group. The results showed a significant difference between the Ang II group and the control group (P < 0.05). The effect of Ang II could be markedly inhibited by Ros (P < 0.05). In addition, Ros did not influence cell proliferation and production of extracellular matrix (P > 0.05). There was a significant difference between the GW9662 + Ros + Ang II group and the Ros + Ang II (P < 0.05).

CONCLUSIONSPPAR-gamma agonists inhibit Ang II-induced proliferation and extracellular matrix synthesis effectively in the hypertrophic scar fibroblasts. Thus PPAR-gamma agonists may have potential therapeutic effect for hypertrophic scar.

Angiotensin II ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cicatrix, Hypertrophic ; metabolism ; Collagen Type I ; biosynthesis ; Extracellular Matrix ; drug effects ; Fibroblasts ; drug effects ; metabolism ; pathology ; Fibronectins ; biosynthesis ; Humans ; PPAR gamma ; agonists

The present study is aimed to investigate the effect of chronic intermittent hypobaric hypoxia (CIHH) on contractile activities in isolated thoracic aorta and pulmonary artery rings and the underlying mechanism in rats. Sprague-Dawley (SD) rats were randomly divided into 4 groups: control group (CON), 14 days CIHH treatment group (CIHH14), 28 days CIHH treatment group (CIHH28) and 42 days CIHH treatment group (CIHH42). CIHH rats were exposed to hypoxia in a hypobaric chamber simulating 5 000 m altitude, 6 h daily for 14, 28 and 42 d, respectively. After artery rings were prepared from pulmonary artery and thoracic aorta, the contractile activity of the artery rings was recorded using organ bath technique. Results are shown as follows. (1) There were no significant differences of noradrenaline (NA)- and KCl-induced contractions in thoracic aorta and pulmonary artery rings among CIHH and CON rats. (2) Angiotensin Ⅱ (ANGⅡ)-induced contraction in thoracic aorta rings, not in pulmonary artery rings, of CIHH rats was decreased compared with that in CON rats. There was no significant difference of ANGⅡ-induced contraction in thoracic aorta rings among CIHH rats. (3) Inhibitory effect of CIHH on ANGⅡ-induced contraction in thoracic aorta rings was endothelium-independent, and was reversed by glibenclamide (Gli), an ATP-sensitive potassium channels (K(ATP)) blocker, and L-NAME, a NO synthase inhibitor, but not by indomethacin (Indo), a cyclooxygenase inhibitor. These results suggest that CIHH attenuates the contraction induced by ANGⅡ in thoracic aorta rings of rat, which is related to the opening of K(ATP) channel and the increased production of NO.
Angiotensin II ; pharmacology ; Animals ; Aorta, Thoracic ; physiopathology ; Hypoxia ; physiopathology ; KATP Channels ; metabolism ; Male ; Muscle Contraction ; physiology ; Muscle, Smooth, Vascular ; physiopathology ; Nitric Oxide ; biosynthesis ; Pulmonary Artery ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Vasoconstriction ; physiology

The effect of NaCl plus 3% chitosan on the systolic blood pressure of spontaneously hypertensive rats (SHR) were evaluated and compared with NaCl plus KCl (NaCl, 49.36% + KCl 49.36%) and chitosan or NaCl treatment alone. In SHR, administration of NaCl plus chitosan (44 mM Na/day) for two months significantly decreased the systolic blood pressure greater than of NaCl plus KCl and NaCl alone. NaCl plus chitosan resulted, though not statistically significant, in decreased urinary Na+ excretion and decreased blood urea nitrogen levels. Urinary creatinine of NaCl plus chitosan was slightly decreased compared to 3 treated groups. Serum electrolytes levels, however, remained unchanged. The combination of NaCl and chitosan may be superior to the conventional use of NaCl plus KCl or NaCl alone in the prevention of hypertension. Even though these supplementary diets have demonstrated potential anti-hypertensive effects in the experimental animal model, further research is needed before any recommendations can be made.
Angiotensin I/blood ; Angiotensin II/biosynthesis ; Animals ; Blood Pressure/*drug effects/physiology ; Blood Urea Nitrogen ; Body Weight/drug effects ; Chitosan/*administration & dosage ; Chlorides/blood/urine ; Creatinine/urine ; Heart/physiology ; Histocytochemistry ; Hypertension/*prevention & control ; Kidney/physiology ; Male ; Potassium/blood/urine ; Potassium Chloride/administration & dosage ; Random Allocation ; Rats ; Rats, Inbred SHR ; Sodium/blood/urine ; Sodium Chloride, Dietary/*administration & dosage ; Systole/drug effects/physiology

OBJECTIVETo express and purify of the BC097361 recombinant protein, and to prepare the BC097361 specific rabbit polyclonal antibody.

METHODSBC097361 cDNA was ligated into the prokaryotic expressive vector pET-32a (+), and the resulting plasmid was transformed into E.coli BL21 (DE3). The protein expression was induced with IPTG and the protein was analyzed with SDS-PAGE and western blotting. The expressed product was purified using Ni+ affinity column chromatography.Then the purified pET-32a (+) -BC097361 fusion protein was used to immunize New Zealand rabbits to gain polyclonal antibody. The specificity and potency of polyclonal antibody were evaluated by Western blot and ELISA.

RESULTSThe BC097361 fusion protein was highly expressed.The protein was mainly in the inclusion body. ELISA indicated the titer of polyclonal antibody more than 1:320000. The high specificity was confirmed with Western blot.

CONCLUSIONSThe recombinant BC097361 fusion protein and the BC097361 specific polyclonal antibody will be valuable tools for the investigation on the biological function of BC097361.

Angiotensin II ; genetics ; Animals ; Antibodies ; immunology ; isolation & purification ; metabolism ; Antibody Specificity ; Blotting, Western ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Genetic Vectors ; genetics ; Liver Cirrhosis ; genetics ; Male ; Plasmids ; genetics ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo evaluate the effect of clearance of superoxide anion by catechin on the expression of nitrogen monoxidum (NO) and endothelial nitricoxide synthase (eNOS) and apoptosis in endothelial progenitor cells (EPCs) induced by angiotensin II (Ang II).

METHODSThe marrow endothelial progenitor cells of Sprague-Dawley rats were isolated and assigned to control (no treatment), Ang II treatment and Ang II + catechin treatment groups. After 48 hrs of culture, the concentration of O2*- in the supernate was measured by the NBT method, and NO concentration in the supernate was measured by the nitrate reductase method; the apoptosis rate of EPCs was detected by the TUNEL method; the mRNA expression of eNOS was detected by RT-PCR; the protein expression of eNOS was detected by Western blot analysis.

RESULTSAng II of 10-6 mol/L was determined as the suitable concentration for cell induction by the MTT test. Catechin of 400 mg/L was determined as an advisable intervention dosage. The apoptosis rate of EPCs in the control, the Ang II and the Ang II+catechin treatment groups were 2.48+/-0.12%, 54.18+/-0.77% and 16.87+/-0.35%, respectively, and there were significant differences among the three groups (P<0.01). The O2*- concentration in the Ang II and the Ang II+catechin treatment groups (81.7+/- 3.6 and 62.3+/- 2.2 U/L respectively) was significantly higher than that in the control group (33.7+/- 2.8 U/L) (P<0.01). An increased NO concentration was also found in the Ang II (189. 8+/- 9.0 micromol/L) and the Ang II+catechin treatment groups (276.4+/- 10.1 micromol/L) compared with that in the control group (105.8+/- 9.8 micromol/L) (P<0.01). There were significant differences in the concentrations of O2*- and NO between the Ang II and the Ang II+catechin treatment groups (P<0.05). The mRNA (P<0.05) and protein expression (P<0.01) of eNOS in the Ang II and the Ang II+catechin treatment groups increased significantly compared with those in the control group. The Ang II+catechin treatment group showed increased eNOS protein expression compared with the Ang II group (P<0.05).

CONCLUSIONSAng II may induce the generation of O2*-, inactivate NO and increase gene and protein expression of eNOS in EPCs. Catechin might decrease the apoptosis of EPCs through the effective clearance of O2*-and the reduction of NO inactivation and of eNOS protein uncoupling.

Angiotensin II ; pharmacology ; Animals ; Apoptosis ; drug effects ; Catechin ; pharmacology ; Cell Survival ; drug effects ; Endothelial Cells ; drug effects ; metabolism ; Female ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; drug effects ; metabolism ; Superoxides ; metabolism

OBJECTIVETo observe the effects of sodium tanshinone II A sulfonate (STS) on angiotensin II (Ang II)-induced hypertrophy of myocardial cells through the expression of phosphorylated extracellular signal-regulated kinase (p-ERK1/2).

METHODSIn the primary culture of neonatal rat myocardial cells, the total protein content in myocardial cells was determined by coomassie brilliant blue and the protein synthesis rate was measured by [3H]-Leucine incorporation as indexes for hypertrophy of myocardial cells. The expression of p-ERK1/2 was determined using Western blot and immunofluorescence labeling.

RESULTS(1) The total protein and protein synthesis rate increased significantly in contrast to the control group after the myocardial cells were stimulated by Ang II (1 micromol/L) for 24 h; STS markedly inhibited the increment of the total protein level induced by Ang II and the syntheses of protein. (2) After pretreatment of myocardial cells with Ang II (1 micromol/L) for 5 min, the p-ERK1/2 protein expression was increased, with the most obvious effect shown at about 10 min; pretreatment of myocardial cells with STS at different doses (2, 10, 50 micromol/L) for 30 min resulted in obvious inhibition of the expression of p-ERK1/2 stimulated by Ang II in a dose-dependent manner. (3) After the myocardial cells were stimulated by Ang II (1 micromol/L), the immunofluorescence of ERK1/2 rapidly appeared in the nucleus. The activation and translocation process of ERK1/2 induced by Ang II was blocked distinctly by STS.

CONCLUSIONSTS inhibited the myocardial cell hypertrophy induced by Ang II, and the mechanism may be associated with the inhibition of p-ERK1/2 expression.

Angiotensin II ; pharmacology ; Animals ; Hypertrophy ; Leucine ; metabolism ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocytes, Cardiac ; drug effects ; enzymology ; pathology ; Phenanthrenes ; pharmacology ; Phosphorylation ; drug effects ; Protein Biosynthesis ; drug effects ; Protein Transport ; drug effects ; Rats ; Rats, Wistar ; Tritium

OBJECTIVETo investigate the mechanisms of angiotonin II (AngII)-induced Ca(2+)-independent pathways mediated by Rho kinase in hepatic stellate cells (HSCs).

METHODSHSC-T6 cells were treated with 1 micromol/L of AngII, and the subsequent cell contraction was directly observed with silicone rubber membrane culture method. The cells with 10 micromol/L AngII treatment were examined for myosin light chain (MLC) phosphorylation level using Western blotting, and the effects of irbesartan (a specific inhibitor of AngII 1- receptor) and Y27632 (a Rho kinase inhibitor) on AngII-induced MLC phosphorylation were evaluated. RT-PCR was used to detect the expression of Rock2 in Ca(2+)- independent pathways mediated by Rho kinase.

RESULTSAngII induced HSC contraction and time-dependent MLC phosphorylation changes, which peaked 15 min after the treatment followed by gradual reduction. Irbesartan or Y27632 treatment significantly lowered MLC phosphorylation level in AngII-induced cells (P<0.01). The mRNA expression of Rock2 increased significantly after AngII treatment (P<0.01), but decreased following subsequent irbesartan or Y27632 treatment.

CONCLUSIONAngII induces HSC contraction through Ca(2+)-independent pathways mediated by Rho kinase.

Angiotensin II ; pharmacology ; Animals ; Blotting, Western ; Cell Movement ; physiology ; Cell Shape ; drug effects ; physiology ; Cells, Cultured ; Hepatic Stellate Cells ; cytology ; drug effects ; metabolism ; Humans ; Phosphorylation ; drug effects ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; drug effects ; rho-Associated Kinases ; biosynthesis ; genetics ; metabolism