The present study was to investigate the role of TRPC6 in pulmonary artery smooth muscle cells (PASMCs) proliferation and apoptosis under hypoxia and hypercapnia. PASMCs were isolated from chloral hydrate-anesthetized male Sprague-Dawley (SD) rats. Cellular purity was assessed by immunofluorescence staining for smooth muscle α-actin under fluorescence microscopy. Passage 4-6 PASMCs were starved for 24 h in serum-free DMEM and divided into 5 groups randomly: normoxia, hypoxia and hypercapnia, DMSO, TRPC6 inhibitor SKF-96365 and TRPC6 activator OAG groups. The normoxic group was incubated under normoxia (5% CO, 21% O, 37 °C) for 24 h, and the others were incubated with corresponding drugs under hypoxic and hypercapnic (6% CO, 5% O, 37 °C) atmosphere for 24 h. TRPC6 mRNA was detected by reverse transcription-PCR. TRPC6 protein was detected by Western blotting. The proliferation of PASMCs was performed by CCK-8 kit. Apoptosis of the PASMCs was detected using TUNEL assay. The [Ca]in the PASMCs was measured using Fura 2-AM fluorescence. The results showed that the expressions of TRPC6 mRNA and protein, and [Ca]were upregulated under hypoxic and hypercapnic conditions. Hypoxia and hypercapnia promoted cellular proliferation and inhibited apoptosis in the PASMCs. OAG enhanced the above-mentioned effects of hypoxia and hypercapnia, whereas SKF-96365 reversed these effects. These results suggest that TRPC6 may play a role in PASMCs proliferation and apoptosis under hypoxia and hypercapnia by regulating [Ca].
Actins ; Animals ; Apoptosis ; Calcium ; metabolism ; Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Hypercapnia ; physiopathology ; Imidazoles ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; Pulmonary Artery ; cytology ; Rats ; Rats, Sprague-Dawley ; TRPC Cation Channels ; metabolism

OBJECTIVETo investigate the effect of hypoxia on the human pulmonary artery smooth muscle cells two pore domain potassium channels TASK-1 and the regulation of non-receptor tyrosine kinase c-Src in this process.

METHODSThe cultured human pulmonary artery smooth muscle cells (hPASMCs) were divided into: normal group, hypoxia 30 minute group, hypoxia 6 hours group and hypoxia 48 hour group, and hypoxia 48 hour + PP2 group, hypoxia 48 hour + PP3 group, hypoxia 48 hour + bpV group. Flow cytometry was used to analyze the cell cycle, RT-PCR and Western blot technique were carried out to detect the expression changes of TASK-1 mRNA and protein in different groups.

RESULTS(1) Cell Cycle Show: Compared with normal control group, with prolonged hypoxia, the percentages of hPASMCs in S phases of cell cycle were increased. While compared with hypoxia 48 hour group, the percentages of hypoxia 48 hour + PP2 group hPASMCs in S phases of cell cycle were decreased. The expression of TASK-1 mRNA on hPASMCs in acute hypoxia 6 hour group was increased, while the expression of TASK-1 protein on hPASMCs in the acute and chronic hypoxia group was decreased, and the expression of TASK-1 mRNA on hPASMCs in the chronic hypoxia group was decreased; After pre-incubation of a potent and selective inhibitor of the Src family of protein tyrosine kinases PP2, the expression of TASK-1 mRNA and protein in hypoxia 48 hour group was increased, however after pre-incubation of the inhibitor of the Src family of protein tyrosine phosphatase bpV, the expression of TASK-1 protein in hypoxia 48 hour group was decreased.

CONCLUSIONHypoxia promotes human pulmonary artery smooth muscle cell proliferation, and non-receptor tyrosine kinase c-Src may participate in the expression of two pore domain potassium channels TASK-1 regulated by hypoxia. Therefore, we hypothesized that TASK-1 channels and c-Src participatein the acute and chronic hypoxic human pulmonary vasoconstriction.

Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Humans ; Myocytes, Smooth Muscle ; cytology ; Nerve Tissue Proteins ; metabolism ; Potassium Channels, Tandem Pore Domain ; metabolism ; Pulmonary Artery ; cytology ; RNA, Messenger ; Vasoconstriction ; src-Family Kinases ; metabolism

OBJECTIVETo evaluate the effect of ulinastatin on hypoxia-induced phenotype modulation of pulmonary artery smooth muscle cells (PASMCs) and explore the underlying mechanism.

METHODSCultured PASMCs from SD rats were exposed to normoxic condition, normoxia with ulinastatin treatment, hypoxia, or hypoxia with ulinastatin treatment. After 24 h of exposures, the cells were examined for SM-α-actin and caplonin expressions with immunofluorescence assay and for cell migration with CCK-8 andH-TdR assays. Western blotting was used for detecting the expressions of PPAR-γ in the cells, and PPAR-γ-responsive firefly luciferase reporter was employed for measuring the transcriptional activity of PPAR-γ. The PPAR-γ inhibitor GW9662 was used to explore the mechanism of the inhibitory effect of ulinastatin on hypoxia induced-phenotype modulation of PASMCs by measuring the changes in cell proliferation and migration.

RESULTSUlinastatin obviously enhanced the expressions of SM-α-actin and calponin (P<0.05), inhibited the proliferation and migration (P<0.05), and up-regulated the expression of PPAR-γ in PASMCs exposed to hypoxia (P<0.05). Pretreatment of the cells with GW9662 abolished the effect of ulinastatin on hypoxia-induced phenotype modulation of PASMCs and enhanced the cell proliferation and migration (P<0.05).

CONCLUSIONUlinastatin inhibits hypoxia-induced phenotype modulation of PASMCs from rats possibly by up-regulating the expression of PPAR-γ.

Actins ; metabolism ; Animals ; Calcium-Binding Proteins ; metabolism ; Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Glycoproteins ; pharmacology ; Microfilament Proteins ; metabolism ; Myocytes, Smooth Muscle ; cytology ; drug effects ; PPAR gamma ; metabolism ; Phenotype ; Pulmonary Artery ; cytology ; Rats ; Rats, Sprague-Dawley ; Up-Regulation

To discuss the effect of puerarin (Pue) on the proliferation of hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) and discuss whether the extracellular signal PI3K/AKT pathway was involved in the Pue-induced PASMC apoptosis. With the serum starvation group (SD group) as the control group, the MTT colorimetry method, Annexin V-FITC apoptosis detection kit and Western blot were used to detect Pue's effect on apoptosis of rat PASMCs. The protein immunoblot assay was used to detect whether PI3K/AKT pathway was involved in the inhibition of hypoxia-induced PASMC apoptosis process. The results show that under normoxic conditions, Pue had no effect on PASMC apoptosis; Under hypoxia conditions, Pue can inhibit PASMC apoptosis; Under normoxic and hypoxic conditions, Pue had no effect on TNF-α expression. Pue can reverse hypoxia-induced Bcl-2 (P <0.01), up-regulate it and down-regulated Bax (P <0.01). Under normoxic conditions, Pue had no effect on P-AKT expression. Both LY294002 and Pue can inhibit hypoxia-induced Bcl-2, up-regulation of P-AKT expression and down-regulation of Bax expression. Compared with the hypoxia + Pue group or the hypoxia + LY294002 group, the hypoxia + Pue + LY294002 group showed more significantly changes in Bcl-2, Bax, P-AKT expressions. The results show that, Pue can inhibit the hypoxic-induced PASMC apoptosis, which may be regulated through PI3K/AKT pathway.
Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Chromones ; pharmacology ; Isoflavones ; pharmacology ; Morpholines ; pharmacology ; Myocytes, Smooth Muscle ; drug effects ; Phosphatidylinositol 3-Kinases ; physiology ; Proto-Oncogene Proteins c-akt ; physiology ; Pulmonary Artery ; cytology ; drug effects ; Rats ; Rats, Wistar ; Signal Transduction ; drug effects

To discuss the effect of puerarin (Pue) on the proliferation of hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) and discuss whether its mechanism is achieved by regulating reactive oxygen. PASMCs of primarily cultured rats (2-5 generations) were selected in the experiment. MTT, Western blot, FCM and DCFH-DA were used to observe Pue's effect the proliferation of PASMCs. The Western blot was adopted to detect whether ROS participated in Pue's effect in inhibiting PASMC proliferation. The PASMCs were divided into five groups: the normoxia group, the hypoxia group, the hypoxia + Pue group, the hypoxia + Pue + Rotenone group and the hypoxia + Rotenone group, with Rotenone as the ROS blocker. According to the results, under the conditions of normoxia, Pue had no effect on the PASMC proliferation; But, under the conditions of hypoxia, it could inhibit the PASMC proliferation; Under the conditions of normoxia and hypoxia, Pue had no effect on the expression of the tumor necrosis factor-α (TNF-α) among PASMCs, could down-regulate the expression of hypoxia-induced cell cycle protein Cyclin A and proliferative nuclear antigen (PCNA). DCFH-DA proved Pue could reverse ROS rise caused by hypoxia. Both Rotenone and Pue could inhibit the up-regulated expressions of HIF-1α, Cyclin A, PCNA caused by anoxia, with a synergistic effect. The results suggested that Pue could inhibit the hypoxia-induced PASMC proliferation. Its mechanism may be achieved by regulating ROS.
Animals ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Hypoxia ; pathology ; Isoflavones ; pharmacology ; Male ; Myocytes, Smooth Muscle ; drug effects ; physiology ; Proliferating Cell Nuclear Antigen ; analysis ; Pulmonary Artery ; cytology ; drug effects ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism

OBJECTIVETo explore the effect of ERK1/2 MAPK pathway on the expression of Kv1.5 channel, a voltage-gated potassium ion channel, in rat pulmonary artery smooth muscle cells (PASMCs) and its mechanisms during the process of hypoxia.

METHODSThe PASMCs derived from SD rats were cultivated primarily. The third to sixth generation of PASMCs were divided into 5 groups randomly: (1) Normal group (N); (2) Hypoxic group (H); (3) Demethy sulfoxide(DMSO) group (HD); (4) U0126 group (HU): 10 micromol/L U0126; (5) Anisomycin group (HA): 10 micromol/L anisomycin. There were three dishes of cells in each group. The cells in normal group were cultured in normoxic incubator (5% CO2, 37 degrees C), the cells in other groups were added to 0.05% DMSO in the hypoxic incubator (5% CO2, 2% O2, 37 degrees C), all cells were cultured for 60 h. RT-PCR and Western blot were used to detected the espressions of Kv1.5 mRNA and protein in PASMCs.

RESULTSCompared with N group, the expressions of Kv1.5 mRNA and protein in H, HD and HA groups were reduced significantly (P < 0.05); Compared with H group and HD groups, Kv1.5 mRNA and protein expressions in HU group were increased sharply (P < 0.05). Compared with the HU group, Kv1.5 mRNA and protein expressions in HA groups were significantly lower (P < 0.05).

CONCLUSIONLow oxygen reduced Kv1.5 mRNA and protein expressions, U0126 could resistant the Kv1.5 channel lower expression caused by hypoxia. Anisomycin had no significant effect on Kv1.5 channel expression under hypoxia, but the expression of Kv1.5 was still significantly lower than the normal oxygen group. These data suggest that hypoxia may cause hypoxic pulmonary hypertension by interfering ERK1/2 signaling pathway to inhibit Kv1.5

Animals ; Cell Hypoxia ; Hypertension, Pulmonary ; Kv1.5 Potassium Channel ; metabolism ; MAP Kinase Signaling System ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; Oxygen ; Pulmonary Artery ; cytology ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley

This paper is to report the exploration of the activation of Rho/ROCK signal pathway in 5-HT-induced proliferation of rat pulmonary artery smooth muscle cells (PASMCs) and the inhibitory effect of m-Nis on this pathway. PASMCs were cultured with the explant technique. MTT assay was used to explore the proliferation of PASMCs after 5-HT treated for different time and the intervening effect of m-Nis. RT-PCR and Western blot were used respectively to explore the mRNA expression of RhoA, ROCK1 and the protein expression of p-MYPT1 in 5-HT-treated PASMCs and intervening effect of m-Nis. The results of MTT assay suggested that 5-HT (1 µmol · L(-1)) treatment for 12-72 h significantly induced the proliferation of rat PASMCs (P<0.05 or P < 0.01), which were inhibited by m-Nis (1 x 10(-5), 1 x 10(-6), l x 10(-7), 1 x10(-8) mol · L(-1)) in dose-dependent manners (P < 0.05 or P < 0.01). Similarly, the mRNA expression of RhoA, ROCK1 and the protein expression of p-MYPT1 were also inhibited by m-Nis in different degrees (P < 0.05 or P < 0.01). Thus, the results of this study suggested that Rho/ROCK pathway played an important role in 5-HT-induced proliferation of rat PASMCs, m-Nis inhibited 5-HT-induced proliferation obviously, which may be related to the blockage of Rho/ROCK signal pathway.
Animals ; Cell Proliferation ; drug effects ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Nisoldipine ; pharmacology ; Protein Phosphatase 1 ; metabolism ; Pulmonary Artery ; cytology ; Rats ; Serotonin ; pharmacology ; Signal Transduction ; rho-Associated Kinases ; metabolism ; rhoA GTP-Binding Protein ; metabolism

OBJECTIVETo explore the effects of NF-κB on proliferation of rat pulmonary artery smooth muscle cells (PASMC) inhibited by simvastatin.

METHODSPASMC isolated from rats and cultured in vitro were randomly divided into four groups (n=6 each): control, platelet-derived growth factor (PDGF) treatment, PDGF+simvastatin treatment, and PDGF+simvastatin+parthenolide (NF-κB inhibitor) treatment. MTT colorimetric assay and flow cytometry were performed to detect cell proliferation and cell cycle distribution. Immunohistochemistry was performed to detect the expression of NF-κB protein. Real-Time PCR was performed to detect NF-κB mRNA expression.

RESULTSCompared with the control group, MTT values of PASMC at all time points, cell proportion at the S phase and G2+M phase, NF-κB protein and mRNA expression increased significantly in the PDGF group (P<0.05). With the intervention of simvastatin, the levels of above indexes decreased compared with the PDGF group (P<0.05). With the intervention of simvastatin and parthenolide, the levels of above indexes decreased more obviously, but were not significantly different from those in the simvastatin intervention group.

CONCLUSIONSSimvastatin can inhibit proliferation of PASMC and cell cycle process. NF-κB may play an important role in the inhibitory effect of simvastatin on the proliferation of PASMC.

Animals ; Cell Proliferation ; drug effects ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; pharmacology ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; physiology ; NF-kappa B ; analysis ; genetics ; physiology ; Pulmonary Artery ; cytology ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Simvastatin ; pharmacology

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

The aim of the present study is to investigate the expressions of ATP-sensitive K(+) channels (KATP) in pulmonary artery smooth muscle cells (PASMCs) and the relationship with p38 MAPK signal pathway in rats. Male SD rat PASMCs were cultured in vitro, and a model of hypoxia and hypercapnia was reconstructed. PASMCs were divided to normal (N), hypoxia-hypercapnia (H), hypoxia-hypercapnia+DMSO incubation (HD), hypoxia-hypercapnia+SB203580 (inhibitor of p38 MAPK pathway) incubation (HS) and hypoxia-hypercapnia+Anisomycin (agonist of p38 MAPK pathway) incubation (HA) groups. Western blot was used to detect the protein expression of SUR2B and Kir6.1; semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of SUR2B and Kir6.1. The results demonstrated that: (1) Compared with N, H, HD and HS groups, the expressions of Kir6.1 mRNA and protein in PASMCs of HA group were decreased significantly (P < 0.01), but there were no differences among N, H, HD and HS groups (P > 0.05); (2) Compared with N group, the expressions of SUR2B mRNA and protein in H, HD, HS and HA groups were increased significantly (P < 0.05), but there were no differences among H, HD, HS and HA groups (P > 0.05). The results imply that: (1) Hypoxia-hypercapnia, SB203580 didn't change the expressions of Kir6.1 mRNA and protein in PASMCs, but Anisomycin decreased the expressions of Kir6.1 mRNA and protein, so Kir6.1 may be regulated by the other subfamily of MAPK pathway; (2) Hypoxia-hypercapnia raised SUR2B mRNA and protein expressions in PASMCs, but SB203580 and Anisomycin did not affect the changes, so the increasing of SUR2B mRNA and protein induced by hypoxia-hypercapnia may be not depend on p38 MAPK pathway.
Animals ; Anisomycin ; pharmacology ; Cell Hypoxia ; Cells, Cultured ; Hypercapnia ; Imidazoles ; pharmacology ; KATP Channels ; metabolism ; MAP Kinase Signaling System ; Male ; Myocytes, Smooth Muscle ; metabolism ; Pulmonary Artery ; cytology ; Pyridines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Sulfonylurea Receptors ; metabolism ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors