The aim of the present study is to investigate the protective effect of chrysin (5,7-dihydroxyflavone) on right ventricular remodeling in a rat model of monocrotaline-induced pulmonary arterial hypertension (PAH). PAH rats were induced by a single injection of monocrotaline (60 mg x kg(-1), sc) and were administered with chrysin (50 or 100 mg x kg(-1) x d(-1)) for 4 weeks. At the end of experiment, the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored via the right jugular vein catheterization into the right ventricle. Right ventricle (RV) to left ventricle (LV) + septum (S) and RV to tibial length were calculated. Right ventricular morphological change was observed by HE staining. Masson's trichrome stain was used to demonstrate collagen deposition. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) levels in right ventricle were determined according to the manufacturer's instructions. The expressions of collagen I, collagen III, NADPH oxidase 4 (NOX4) and nuclear factor-kappa B (NF-κB) were analyzed by immunohistochemisty, qPCR and (or) Western blot. The results showed that chrysin treatment for 4 weeks attenuated RVSP, mPAP and right ventricular remodeling index (RV/LV+S and RV/Tibial length) of PAH rats induced by monocrotaline. Furthermore, monocrotaline-induced right ventricular collagen accumulation and collagen I and collagen III expression were both significantly suppressed by chrysin. The expressions of NOX4, NF-κB and MDA contents were obviously decreased, while the T-AOC was significantly increased in right ventricule from PAH rats with chrysin treatment. These results suggest that chrysin ameliorates right ventricular remodeling of PAH induced by monocrotaline in rats through its down-regulating of NOX4 expression and antioxidant activity, and inhibiting NF-κB expression and collagen accumulation.
Animals ; Blotting, Western ; Collagen ; metabolism ; Disease Models, Animal ; Flavonoids ; pharmacology ; Heart Ventricles ; drug effects ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; Monocrotaline ; toxicity ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NF-kappa B ; metabolism ; Rats ; Ventricular Remodeling ; drug effects

Pulmonary arterial hypertension (PAH) causes right ventricular failure due to a gradual increase in pulmonary vascular resistance. The purposes of this study were to confirm the engraftment of human umbilical cord blood-mesenchymal stem cells (hUCB-MSCs) placed in the correct place in the lung and research on changes of hemodynamics, pulmonary pathology, immunomodulation and several gene expressions in monocrotaline (MCT)-induced PAH rat models after hUCB-MSCs transfusion. The rats were grouped as follows: the control (C) group; the M group (MCT 60 mg/kg); the U group (hUCB-MSCs transfusion). They received transfusions via the external jugular vein a week after MCT injection. The mean right ventricular pressure (RVP) was significantly reduced in the U group after the 2 week. The indicators of RV hypertrophy were significantly reduced in the U group at week 4. Reduced medial wall thickness in the pulmonary arteriole was noted in the U group at week 4. Reduced number of intra-acinar muscular pulmonary arteries was observed in the U group after 2 week. Protein expressions such as endothelin (ET)-1, endothelin receptor A (ERA), endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 significantly decreased at week 4. The decreased levels of ERA, eNOS and MMP-2 immunoreactivity were noted by immnohistochemical staining. After hUCB-MSCs were administered, there were the improvement of RVH and mean RVP. Reductions in several protein expressions and immunomodulation were also detected. It is suggested that hUCB-MSCs may be a promising therapeutic option for PAH.
Animals ; Cytokines/metabolism ; Disease Models, Animal ; Endothelin-1/metabolism ; Fetal Blood/*cytology ; Gene Expression Regulation/drug effects ; Hemodynamics ; Humans ; Hypertension, Pulmonary/chemically induced/*therapy ; Hypertrophy, Right Ventricular/physiopathology ; Immunohistochemistry ; Lung/metabolism/pathology ; Male ; Matrix Metalloproteinase 2/metabolism ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology/metabolism ; Monocrotaline/toxicity ; Nitric Oxide Synthase Type III/metabolism ; Pulmonary Artery/pathology ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A/metabolism

OBJECTIVETo investigate the protective effects of rutaecarpine (Rut) on right ventricular remodeling in rats with monocrotaline-induced pulmonary hypertension (PH).

METHODForty-eight SD rats were fed adaptively for 1 week and then were randomly divided into the following 4 groups (n = 12): normal control group, monocrotaline (MCT) treatment group, MCT treatment with Rut (20 mg/kg)group and MCT treatment with Rut (40 mg/kg) group. PH rats were induced by a single injection of monocrotaline (60 mg/kg, sc) and were administered with Rut (20 or 40 mg/kg/d) for 4 weeks. At the end of experiment, the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored via the right jugular vein catheterization into the right ventricle. The ratio of right ventricle (RV) to left ventricle (LV) + septum (S) and the ratio of RV to tibial length were calculated. Right ventricular morphological changes were deserved by HE staining. Masson's trichrome staining was used to display collagen deposition. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) levels in right ventricle were determined according to the manufacturer's instructions. mRNA and protein expression levels of NOX4, collagen I and collagen III were analyzed by immunohistochemisty, real-time PCR and Western blot.

RESULTSThe results showed that Rut treatment for 4 weeks attenuated RVSP, mPAP and right ventricular remodeling index (RV/LV + S and RV/Tibial length) of PH rats induced by monocrotaline. Furthermore, the right ventricular collagen deposition and collagen I and collagen I expression induced by MCT were both significantly suppressed by Rut. The expression levels of NOX4 and MDA were obviously decreased, while the T-AOC was significantly increased in right ventricular from PH rats treated with Rut.

CONCLUSIONThese results suggested that Rut ameliorates the right ventricular remodeling in rats with PH induced by MCT through down-regulating of NOX4 expression and collagen accumulation.

Animals ; Antioxidants ; metabolism ; Heart Ventricles ; metabolism ; Hypertension, Pulmonary ; chemically induced ; drug therapy ; Indole Alkaloids ; pharmacology ; Male ; Malondialdehyde ; metabolism ; Monocrotaline ; adverse effects ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; Quinazolines ; pharmacology ; Rats ; Ventricular Remodeling ; drug effects

OBJECTIVETo observe the change of apelin and its receptor (APJ) in the lung tissue of rats with pulmonary hypertension induced by monocrotaline and to explore its significance.

METHODSTwenty-five male SD rats were randomly divided into control group (n = 10) and monocrotaline group (n = 15). On the twenty-first day after the rats were intraperitoneally injected 60 mg/kg monocrotaline for monocrotaline group or equal volume vehicle for control group, the mean pulmonary artery pressure was measured by right heart catheterization. Histopathological study of lung tissue was done with hematoxylin-eosin (HE) and Masson's trichrome staining. The concentration of apelin in the plasma was measured by radioimmunoassay. The expressions of apelin/APJ proteins and genes in lung tissue were measured respectively by Western blot and reverse transcription polymerase chain reaction (RT-PCR).

RESULTSThe mean pulmonary arterial pressure, right ventricular hypertrophy, pulmonary vascular remodeling index, content of apelin protein in lung tissue of monocrotaline group were higher than those in control group. APJ protein and gene expression in monocrotaline group were significantly lower than those in control group (P < 0.01, P < 0.05), but apelin gene expression in the lung tissue between the two groups had no significant difference.

CONCLUSIONEndogenous apelin/APJ dysfunction may play an important role in the development of pulmonary hypertension induced by monocrotaline.

Animals ; Apelin ; Apelin Receptors ; Hypertension, Pulmonary ; chemically induced ; metabolism ; Intercellular Signaling Peptides and Proteins ; metabolism ; Lung ; metabolism ; Male ; Monocrotaline ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; metabolism

The purpose of this study was to investigate the therapeutic effects of small hairpin RNA (shRNA) targeting endothelin-converting enzyme (ECE)-1 in monocrotaline (MCT)-induced pulmonary hypertensive rats. Ninty-four Sprague-Dawley rats were divided into three groups: control (n = 24), MCT (n = 35) and shRNA (n = 35). Four-week survival rate in the shRNA group was significantly increased compared to that in the MCT group. The shRNA group showed a significant improvement of right ventricular (RV) pressure compared with the MCT group. The MCT and shRNA groups also showed an increase in RV/(left ventricle + septum) ratio and lung/body weight. Plasma endothelin (ET)-1 concentrations in the shRNA group were lower than those in the MCT group. Medial wall thickness of pulmonary arterioles were increased after MCT injection and was significantly decreased in the shRNA group. The number of intra-acinar muscular pulmonary arteries was decreased in the shRNA group. The mRNA expressions of ET-1 and ET receptor A (ETA) were significantly decreased in the shRNA group in week 4. The protein levels of ETA were decreased in the shRNA group in week 2. The protein levels of tumor necrosis factor-alpha and vascular endothelial growth factor were decreased in the shRNA group in week 4. In conclusion, the gene silencing with lentiviral vector targeting ECE-1 could be effective against hemodynamic, histopathological and gene expression changes in pulmonary hypertension.
Animals ; Aspartic Acid Endopeptidases/*antagonists & inhibitors/blood/genetics ; Body Weight ; Heart Ventricles/physiopathology ; Hypertension, Pulmonary/chemically induced/*enzymology/mortality ; Lentivirus/genetics ; Lung/anatomy & histology/metabolism/pathology ; Male ; Metalloendopeptidases/*antagonists & inhibitors/blood/genetics ; Monocrotaline/toxicity ; Pulmonary Artery/drug effects/physiopathology ; RNA, Small Interfering/*metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A/genetics/metabolism ; Survival Rate ; Tumor Necrosis Factor-alpha/metabolism ; Vascular Endothelial Growth Factor A/metabolism

OBJECTIVETo study the effect of genistein on the expression of heme oxygenase-1 (HO-1) in rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT).

METHODSSixty male Sprague-Dawley rats were randomly divided into 4 groups (n=15), namely the control group, model group, low-dose (20 µg/kg) genistein group and high-dose (80 µg/kg) genistein group. The hemodynamic parameters were measured and the remodeling of pulmonary small arteries was observed by electron microscope (EM). The expression of HO-1 in the lung tissues were detected by Western blotting.

RESULTSCompared with the model group, genistein treatment significantly reduced the elevated mean pulmonary arterial pressure, improved the right ventricular hypertrophy index, and increased the expression of HO-1 in a dose-dependent manner.

CONCLUSIONGenistein attentuates pulmonary arterial hypertension in MCT-treated rats possibly by up-regulation of HO-1 in the lung tissues.

Animals ; Genistein ; pharmacology ; therapeutic use ; Heme Oxygenase (Decyclizing) ; metabolism ; Hypertension, Pulmonary ; chemically induced ; drug therapy ; enzymology ; Lung ; enzymology ; pathology ; Male ; Monocrotaline ; Rats ; Rats, Sprague-Dawley ; Up-Regulation ; drug effects

OBJECTIVETo explore the mechanism of pulmonary hypertension and Cor Pulmonale rat models induced by monocrotaline (MCT).

METHODSTwenty Wistar male rats were randomly divided into normal control group and model group (n= 10), which received a single intraperitoneal injection of MCT solution (50 mg/kg , the first day) or dissolvant, respectively. On day 28 after MCT administration, the hemodynamic parameters were assessed; levels of tumour necrosis factor-alpha (TNF-alpha), nitric oxide (NO), endothelin-1 (ET-1), B-type natriuretic peptide(BNP) in pulmonary tissue or blood were measured using radio immunoassay or nitrate reductase method.

RESULTS28 days after MCT injection, compared with control group, right ventricle systolic pressure (RVSP) increased and heart rate(HR), mean arterial pressure (MAP) decreased; Levels of TNF-alpha, NO, ET-1 in pulmonary tissue or blood increased significantly in MCT group.

CONCLUSIONThe potential mechanism of MCI- induced pulmonary hypertension and Cor Pulmonale rat models associates with increasing TNF-alpha, NO, ET-1 levels in vivo, which results from inflammatory injury of lung tissue and blood vessels induced by MCT.

Animals ; Disease Models, Animal ; Endothelin-1 ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; physiopathology ; Lung ; metabolism ; Male ; Monocrotaline ; adverse effects ; Nitric Oxide ; metabolism ; Pulmonary Heart Disease ; chemically induced ; metabolism ; physiopathology ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; metabolism

Pulmonary artery hypertension (PAH) causes right ventricular failure and possibly even death by a progressive increase in pulmonary vascular resistance. Bone marrow-derived mesenchymal stem cell therapy has provided an alternative treatment for ailments of various organs by promoting cell regeneration at the site of pathology. The purpose of this study was to investigate changes of pulmonary haemodynamics, pathology and expressions of various genes, including ET (endothelin)-1, ET receptor A (ERA), endothelial nitric oxide synthase (NOS) 3, matrix metalloproteinase (MMP) 2, tissue inhibitor of matrix metalloproteinase (TIMP), interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in monocrotaline (MCT)-induced PAH rat models after bone marrow cell (BMC) transfusion. The rats were grouped as the control (C) group, monocrotaline (M) group, and BMC transfusion (B) group. M and B groups received subcutaneous (sc) injection of MCT (60 mg/kg). BMCs were transfused by intravenous injection at the tail 1 week after MCT injection in B group. Results showed that the average RV pressure significantly decreased in the B group compared with the M group. RV weight and the ratio of RH/LH+septum significantly decreased in the B group compared to the M group. Gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-alpha significantly decreased in week 4 in the B group compared with the M group. In conclusion, BMC transfusion appears to improve survival rate, RVH, and mean RV pressure, and decreases gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-alpha.
Animals ; Bone Marrow Cells/*cytology ; *Bone Marrow Transplantation ; Cytokines/genetics/metabolism ; Enzymes/genetics/metabolism ; Gene Expression Regulation ; Hypertension, Pulmonary/chemically induced/*metabolism/pathology ; Lung/metabolism ; Male ; Monocrotaline/toxicity ; Pulmonary Artery/physiology ; Rats ; Rats, Sprague-Dawley ; Survival Rate ; Ventricular Function/physiology

Pulmonary arterial hypertension is associated with profound vascular remodeling and alterations in Ca2+ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Recent studies show that canonical transient receptor potential channel 6 (TRPC6) genes, which encode receptor-operated cation channels (ROCC) in PASMCs, play an important role in Ca2+ regulation and cell proliferation. The aim of the present study was to investigate the role of TRPC6 in monocrotaline (MCT)-induced pulmonary artery hypertension. Sprague-Dawley rats were randomly divided into normal control group and MCT group. In MCT group, pulmonary arterial hypertension was induced by a single intraperitoneal injection of MCT at a dose of 60 mg/kg. After 3 weeks, the right ventricular systolic pressure (RVSP) and the right ventricular mass index (RVMI) were measured. The lung sections were stained by HE and observed under light microscope. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot were performed to detect the expression of TRPC6 in rat pulmonary arteries. The 1-oleoyl-2-acetyl-sn-glycerol (OAG)-induced contractile tension of pulmonary arteries were measured by vascular ring tension analysis and the intracellular Ca2+ concentration ([Ca2+](i))of PASMCs was monitored using Fluo3-AM assay. The results showed that RVSP and RVMI markedly elevated in MCT group (P<0.01) in comparison to CON group. The thickness of pulmonary vascular smooth muscles was increased and the inner diameter of pulmonary arteries was diminished in MCT group. Though there was no significant difference in the levels of mRNA and protein of TRPC6 between CON and MCT groups, the application of OAG, which can directly activate ROCC, induced greater contraction tension of pulmonary arteries (P<0.01) and more Ca2+ entries in PASMCs (P<0.05) in MCT group compared to those in control group. These results indicate that MCT induces pulmonary artery hypertension and thus remodeling of the right ventricle and pulmonary arteries in rats. The expression of mRNA and protein of TRPC6 is not potentiated by MCT, but the TRPC6/ROCC-mediated Ca2+ entry in PASMCs and vascular tone of pulmonary arteries are significantly increased with MCT treatment.
Animals ; Calcium ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; physiopathology ; Male ; Monocrotaline ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Myocytes, Smooth Muscle ; cytology ; metabolism ; Pulmonary Artery ; cytology ; metabolism ; physiopathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; TRPC Cation Channels ; genetics ; metabolism

OBJECTIVETo evaluate the contribution of platelet and leukocyte activation in pathogenesis primary pulmonary hypertension (PPH).

METHODSPulmonary hypertension was induced by subcutaneous injection of 2% monocrotaline (MCT) in male Prague-Dawley (SD) rats. Blood samples were collected at the third week after MCT injection, and flow cytometry was used to determine the fibrinogen-binding platelet, CD11b expression on leukocyte and platelet-leukocyte aggregation.

RESULTThree weeks after MCT injection, rats exhibited higher right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure(mPAP), as compared with controls. MCT induced vascular remodeling characterized by vascular medial wall thickening in pulmonary muscular arteries. The ratio of platelets fibrinogen binding was increased in rats 3 weeks after MCT injection than that of control group[(4.08 +/-1.59)% compared with (1.45 +/- 0.61)%, P<0.01]. CD11b expression in monocytes and neutrophils, but not in lymphocytes was increased significantly 3 weeks after MCT injection (P <0.01). Platelet-neutrophil aggregations increased in MCT injected rats as compared with controls (P <0.01).

CONCLUSIONRats of PPH model demonstrate enhanced circulating platelet and leukocyte activation, which may contribute to the pathogenesis of PPH.

Animals ; Blood Platelets ; metabolism ; Fibrinogen ; metabolism ; Hypertension, Pulmonary ; blood ; chemically induced ; Leukocytes ; physiology ; Male ; Monocrotaline ; Platelet Aggregation ; Platelet Count ; Random Allocation ; Rats ; Rats, Sprague-Dawley