phenanthrenes and Hypertension--Pulmonary

Recent studies have demonstrated the beneficial effects of STS in treating pulmonary hypertension by inhibiting the pulmonary vascular remodeling and suppressing the abnormally elevated proliferation and migration of PASMCs. However, the roles of STS on pulmonary vascular endothelium remain largely known.. In this study, we investigated the effects and mechanisms of STS on pulmonary vascular endothelial dysfunction by using a chronic hypoxia-induced pulmonary hypertension (HPH) rat model, as well as in primarily cultured rat PMVECs and human ESC-ECs cell models.. Firstly, a 21-day treatment of STS significantly prevents the disease development of HPH by normalizing the right ventricular systolic pressure and right ventricular hypertrophy, improving the cardiac output. Then, STS treatment markedly inhibits the hypoxia-induced medial wall thickening of the distal intrapulmonary arteries. Notably, STS significantly inhibits the hypoxia-induced apoptosis in both the pulmonary endothelium of HPH rats and primarily cultured PMVECs, through the stabilization of BMPR2 protein and protection of the diminished BMP9-BMPR2-Smad1/5/9 signaling pathway. In mechanism, STS treatment retrieves the hypoxic downregulation of BMPR2 by stabilizing the BMPR2 protein, inhibiting the BMPR2 protein degradation via lysosome system, and promoting the plasma membrane localization of BMPR2, all of which together reinforcing the BMP9-induced signaling transduction in both PMVECs and human ESC-ECs. However, these effects are absent in hESC-ECs expressing heterozygous dysfunctional BMPR2 protein (BMPR2. STS may exert anti-apoptotic roles, at least partially, via induction of the BMP9-BMPR2-Smad1/5/9 signaling transduction in pulmonary endothelium and PMVECs.

Topics: Animals; Bone Morphogenetic Protein Receptors, Type II; Cells, Cultured; Endothelial Cells; Human Embryonic Stem Cells; Humans; Hypertension, Pulmonary; Hypoxia; Phenanthrenes; Pulmonary Artery; Rats; Signal Transduction; Smad1 Protein

Our laboratory previously showed that sodium tanshinone IIA sulfonate (STS) inhibited store-operated Ca(2+) entry (SOCE) through store-operated Ca(2+) channels (SOCC) via downregulating the expression of transient receptor potential canonical proteins (TRPC), which contribute to the formation of SOCC (Wang J, Jiang Q, Wan L, Yang K, Zhang Y, Chen Y, Wang E, Lai N, Zhao L, Jiang H, Sun Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 48: 125-134, 2013). The detailed molecular mechanisms by which STS inhibits SOCE and downregulates TRPC, however, remain largely unknown. We have previously shown that, under hypoxic conditions, inhibition of protein kinase G (PKG) and peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling axis results in the upregulation of TRPC (Wang J, Yang K, Xu L, Zhang Y, Lai N, Jiang H, Zhang Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 49: 231-240, 2013). This suggests that strategies targeting the restoration of this signaling pathway may be an effective treatment strategy for pulmonary hypertension. In this study, our results demonstrated that STS treatment can effectively prevent the hypoxia-mediated inhibition of the PKG-PPAR-γ signaling axis in rat distal pulmonary arterial smooth muscle cells (PASMCs) and distal pulmonary arteries. These effects of STS treatment were blocked by pharmacological inhibition or specific small interfering RNA knockdown of either PKG or PPAR-γ. Moreover, targeted PPAR-γ agonist markedly enhanced the beneficial effects of STS. These results comprehensively suggest that STS treatment can prevent hypoxia-mediated increases in intracellular calcium homeostasis and cell proliferation, by targeting and restoring the hypoxia-inhibited PKG-PPAR-γ signaling pathway in PASMCs.

Topics: Animals; Calcium Signaling; Cell Proliferation; Cells, Cultured; Cyclic GMP-Dependent Protein Kinases; Disease Models, Animal; Dose-Response Relationship, Drug; Hypertension, Pulmonary; Hypoxia; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Phenanthrenes; PPAR gamma; Protein Kinase Inhibitors; Pulmonary Artery; Rats, Sprague-Dawley; RNA Interference; Time Factors; Transfection; TRPC Cation Channels; Vascular Remodeling

To investigate the effect of sodium tanshinone IIA sulfonate (STS) on rat right ventricular systolic pressure (RVSP), mean right ventricular pressure (MRVP), right ventricular hypertrophy index [RV/(LV+S)], pulmonary vascular remodeling, and PPARγ protein expression in pulmonary artery smooth muscle of monocrotaline (MCT) induced rat pulmonary hypertension model.. The pulmonary hypertension model was established by subcutaneously injection of MCT, and the rats were treated with or without STS for 21 days. After that, RVSP, mRVP and RV/(LV+S) were measured. Lung histopathological sections were prepared, and the lumen area, the wall thickness and arterial radius of pulmonary arteries were quantified using the Image Pro Plus 6.0 software. PPARγ protein expression in rat pulmonary artery smooth muscle was detected by Western blot.. Compared with control group, the RVSP, mRVP were significantly increased in MCT group (P < 0.05), while in the MCT+STS group, it was decreased from (81.2 ± 1.9) and (28.6 ± 2.0) mmHg to (35.4 ± 8.3) and (14.1 ± 5.4) mmHg, respectively (P < 0.05). The RV/(LV+S) of MCT group was (0.57 ± 0.04), markedly higher than those of control group and control+STS group (0.33 ± 0.02) and (0.34 ± 0.02) , respectively, P < 0.05, while in MCT+STS group, the RV/(LV+S) was (0.43 ± 0.02), lower than that of MCT group (P < 0.05) ;The luminal area/total area of MCT group decreased to (27 ± 6)%compared with control rats (56.00 ± 3.00) % (P < 0.05) . The wall thickness/artery radius (WT%) of MCT group increased from (20 ± 4) % (control group) to (40 ± 3) % (P < 0.05) .In MCT+STS treated rats, luminal area/ total area and WT% were (39.0 ± 2.0) %and (31.0 ± 2.0) %, both statistically different from MCT group (P < 0.05) . The level of PPARγ protein in pulmonary artery smooth muscle of MCT group was (48 ± 4) %, lower than control group (100 ± 0) % (P < 0.05) .In the MCT+STS group, PPARγ protein expression was recovered (102 ± 3) %, (P < 0.05) .. STS markedly decreased RVSP,MRVP, RV/(LV+S) and pulmonary vascular remodeling in MCT induced pulmonary hypertension rat, and PPARγ might be targeted as a key molecule during STS treatment.

Topics: Animals; Hypertension, Pulmonary; Lung; Male; Monocrotaline; Muscle, Smooth, Vascular; Phenanthrenes; PPAR gamma; Pulmonary Artery; Rats; Rats, Sprague-Dawley

Danshen, the dried root of Salvia miltiorrhiza, is widely used in clinics in China for treating various diseases, including cardiovascular diseases. Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA isolated as the major active component from Danshen, was recently reported to be effective in attenuating the characteristic pulmonary vascular changes associated with chronically hypoxic pulmonary hypertension (CHPH); however, the underlying detailed mechanisms are poorly understood. In this study, we investigated the effects of STS on basal intracellular Ca(2+) concentration ([Ca(2+)](i)) and store-operated Ca(2+) entry (SOCE) in distal pulmonary arterial smooth muscle cells (PASMCs) exposed to prolonged hypoxia or isolated from CHPH rats. SOCE measured by Mn(2+) quenching of Fura-2 fluorescence in PASMCs from rats exposed to chronic hypoxia (10% O(2), 21 d) was increased by 59%, and basal [Ca(2+)](i) was increased by 119%; this effect was inhibited by intraperitoneal injection of STS. These inhibitory effects of STS on hypoxic increases of SOCE and basal [Ca(2+)](i) were associated with reduced expression of canonical transient receptor potential (TRPC)1 and TRPC6 in distal pulmonary arterial smooth muscle and decreases on right ventricular pressure, right ventricular hypertrophy, and peripheral pulmonary vessel thickening. In ex vivo cultured distal PASMCs from normoxic rats, STS (0-25 μM) dose-dependently inhibited hypoxia-induced cell proliferation and migration, paralleled with attenuation in increases of basal [Ca(2+)](i), SOCE, mRNA, and protein expression of TRPC1 and TRPC6. STS also relieved right ventricular systolic pressure, right ventricular hypertrophy, and TRPC1 and TRPC6 protein expression in distal pulmonary arteries in a monocrotaline-induced rat model of pulmonary arterial hypertension. These results indicate that STS prevents pulmonary arterial hypertension development likely by inhibiting TRPC1 and TRPC6 expression, resulting in normalized basal [Ca(2+)](i) and attenuated proliferation and migration of PASMCs.

Topics: Animals; Calcium; Calcium Channels; Cell Movement; Cell Proliferation; Drugs, Chinese Herbal; Hemodynamics; Hypertension, Pulmonary; Hypoxia; Male; Muscle, Smooth, Vascular; Phenanthrenes; Phytotherapy; Pulmonary Artery; Rats; Rats, Sprague-Dawley; Salvia miltiorrhiza; Transient Receptor Potential Channels; TRPC Cation Channels

The present study was designed to investigate the vascular effects and underlying mechanisms of tanshinone IIA on isolated rat pulmonary artery. Isometric tension was recorded in the arteries from normal and hypoxic pulmonary hypertension rats under normoxia or hypoxia condition. The results showed that tanshinone IIA exerted a biphasic effect on rat pulmonary artery. The constriction was attenuated by endothelium-denudation but was enhanced by inhibition of nitric oxide synthase. Pretreatment with tetraethylammonium (Ca2+-activated K+ channel inhibitor) upward shifted the concentration-response curve without affecting the maximum dilatation. Pretreatment with zinc protoporphyrin IX (heme oxygenase-1 inhibitor), 4-aminopyridine (KV channel inhibitor), glibenclamide (KATP channel inhibitor) or BaCl2 (inwardly rectifying K+ channel inhibitor) did not affect the vasoreactivity. Meanwhile, tanshinone IIA almost abolished vasoconstriction induced by extracellular Ca2+. Under hypoxia condition, tanshinone IIA eliminated acute hypoxia-induced initial contraction, potentiated following vasorelaxation, attenuated and reversed sustained contraction to relaxation in pulmonary artery from normal rats, and reversed phenylephrine-induced sustained constriction to sustained relaxation in remodeled pulmonary artery from hypoxic pulmonary hypertension rats. We concluded that the mild constrictive effect induced by tanshinone IIA was affected by integrity of endothelium and production of nitric oxide, while the potent dilative effect was endothelium-independent and produced primarily by inhibiting extracellular Ca2+ influx and partially by inhibiting intracellular Ca2+ release, as well as activating Ca2+-activated K+ channels. The modulation of tanshinone IIA on pulmonary vasoreactivity under both acute and chronic hypoxia condition may provide a new insight for curing hypoxic pulmonary hypertension.

Topics: Abietanes; Animals; Calcium; Carbon Monoxide; Endothelium, Vascular; Extracellular Space; Hypertension, Pulmonary; Hypoxia; In Vitro Techniques; Intracellular Space; Male; Nitric Oxide; Phenanthrenes; Phenylephrine; Potassium; Potassium Channel Blockers; Prostaglandins; Pulmonary Artery; Rats; Rats, Sprague-Dawley; Vasoconstriction

To investigate the effect of sodium tanshinone IIA sulphonate (STS), a water-soluble derivative of tanshinone II A, on hypoxic pulmonary hypertension (HPH) in rats and its underlying mechanisms.. Rats were exposed to hypoxia for two or three weeks, pretreated with or without STS. We detected mean pulmonary arterial pressure (mPAP), the ratio of right ventricle weight to left ventricle with septum weight [RV/(LV+S)], wall thickness and voltage-activated potassium channel (Kv) 2.1 mRNA level of pulmonary arteries (PAs), respectively, and the in vitro effects of STS on proliferation and Kv2.1 expression of cultured pulmonary smooth muscle cells (PASMCs) from normal rats. Cell proliferation was determined by 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyltetrazoliumbromiede (MTT) assay and direct cell counting. Kv2.1 mRNA and protein level were evaluated by reverse transcription-polymerase chain reaction and Western blot, respectively.. Chronic hypoxia increased values of mPAP and RV/(LV+S) and inhibited Kv2.1 mRNA level in PAs. Three weeks' daily STS pretreatment inhibited the hypoxia-induced increased mPAP and RV/(LV+S), pulmonary arterial thickening and up-regulated Kv2.1 mRNA level in PAs. Further study in vitro showed that STS suppressed significantly hypoxia-induced PASMCs proliferation and inhibition of Kv2.1 expression in PASMCs.. STS might play protective effects on HPH through decreasing mPAP, V/(LV+S) and inhibiting structural remodeling in distal PAs. The mechanism of these effects may be attributed to inhibiting PASMCs proliferation and stimulating Kv2.1 expression.

Topics: Animals; Cells, Cultured; Dose-Response Relationship, Drug; Hypertension, Pulmonary; Hypoxia; Male; Molecular Structure; Myocytes, Smooth Muscle; Phenanthrenes; Pulmonary Artery; Random Allocation; Rats; Rats, Sprague-Dawley; Shab Potassium Channels

It has been shown that triptolide can attenuate pulmonary arterial hypertension in rats. This study was designed to investigate the therapeutic effect of triptolide on pulmonary hypertension in rats and possible mechanisms.. Sixty Sprague-Dawley (SD) rats were randomly divided into 6 groups: normal control, model, continuous triptolide-treated, delayed triptolide-treated and two placebo groups for continuous and delayed fashions (n=10 each). The rats from the last 5 groups were injected with monocrotaline (MCT, 60 mg/kg) on day 7 after left pneumonectomy. The rats in the continuous triptolide-treated group received therapy from day 5 to 35 with triptolide (0.25 mg/kg intraperitoneally, every other day) and those in the delayed triptolide-treated received therapy with triptolide (0.20 mg/kg intraperitoneally, daily) from day 21 to 35 after operation. The hemodynamic parameters were detected by catheterization and the pathologic changes of small pulmonary arteries were evaluated by light microscopy 5 weeks post-operation. The expression of matrix metalloproteinases (MMPs) was assessed by immunohistochemistry and quantitative fluorescence PCR of relevant (MMP2 and MMP9) mRNAs.. By day 35 after operation, the mean pulmonary arterial pressure (mPAP, 38.10+/-1.20 vs 16.70+/-1.16 mmHg)the ratio of right ventricle/left ventricle plus septum [RV/(LV+S), 62.45+/-5.28% vs 22.76 +/-3.01%] and the vessel obstructive scores (VOS, 1.736 +/-0.080 vs 0.000 +/-0.000) increased significantly in the Model group compared with those of the normal control group (P < 0.01). The expression of MMP2 and MMP9 and their mRNA expression in lung tissues obviously also elevated in the Model group (P < 0.05). The continuous and the delayed triptolide-treated groups had significantly lower mPAP (20.80+/-1.03 and 26.20+/-1.03 mmHg, respectively) and less right ventricular hypertrophy and pulmonary arterial neointimal formation compared with the model and the placebo groups. The two treated groups also demonstrated decreased expression of MMP2 and MMP9 and their mRNA expression in lung tissues. There were significant differences in mPAP, RV/(LV+S) and VOS between the two triptolide-treated groups.. Triptolide attenuates the development of pulmonary hypertention and right ventricular hypertrophy and promotes regression of pulmonary arterial neointimal formation in pneumonectomized rats that received MCT, possibly through an inhibition of MMPs activity.

Topics: Animals; Diterpenes; Epoxy Compounds; Hypertension, Pulmonary; Immunohistochemistry; Lung; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Phenanthrenes; Rats; Rats, Sprague-Dawley; RNA, Messenger

To investigate the effect of Triptolide on the development of monocrotaline(MCT)-induced pulmonary hypertension and right ventricular hypertrophy in pneumonectomized rat.. Sixty male Sprague-Dawley rats were randomly divided into continuous Triptolide therapy group, delayed Triptolide therapy group, two placebo groups, model group and normal group, of which the mean pulmonary arterial pressure (mPAP), right ventricular index (RV/LV+S) were observed or checked. The light microscope, image analysis and immunohistochemistry were used to show percent vascular wall thickness (WT%), the degree of muscularization and vascular occlusion score in pulmonary arteries.. (1) Each index of model group was obviously increased (P < 0.01 vs. common group). (2) The indexes of two therapy groups were attenuated for the pneumonectomized rats that suffered from MCT induced pulmonary hypertension (P < 0.05 vs. model group and placebo group). (3) There was the statistics significance between the two therapy groups in all indexes except for the degree of muscularization (P < 0.05).. For pneumonectomized rats that suffer from the MCT pulmonary hypertension and undergo the pulmonary vascular remodeling, triptolide can slow down pulmonary hypertension, right ventricular bypertrophy and promote the regression of pulmonary arterial neointimal formation before and after forming pulmonary hypertension.

Topics: Animals; Antihypertensive Agents; Diterpenes; Epoxy Compounds; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Male; Monocrotaline; Phenanthrenes; Pneumonectomy; Rats; Rats, Sprague-Dawley

Pneumonectomized rats injected with the alkaloid toxin, monocrotaline, develop progressive neointimal pulmonary vascular obliteration and pulmonary hypertension resulting in right ventricular failure and death. The antiproliferative immunosuppressant, triptolide, attenuates neointimal formation and pulmonary hypertension in this disease model (Faul JL, Nishimura T, Berry GJ, Benson GV, Pearl RG, and Kao PN. Am J Respir Crit Care Med 162: 2252-2258, 2000). Pneumonectomized rats, injected with monocrotaline on day 7, were killed at days 14, 21, 28, and 35 for measurements of physiology and gene expression patterns. These data were compared with pneumonectomized, monocrotaline-injected animals that received triptolide from day 5 to day 35. The hypothesis was tested that a group of functionally related genes would be significantly coexpressed during the development of disease and downregulated in response to treatment. Transcriptional analysis using total lung RNA was performed on replicate animals for each experimental time point with exploratory data analysis followed by statistical significance analysis. Marked, statistically significant increases in proteases (particularly derived from mast cells) were noted that parallel the development of vascular obliteration and pulmonary hypertension. Mast-cell-derived proteases may play a role in regulating the development of neointimal pulmonary vascular occlusion and pulmonary hypertension in response to injury.

Topics: Animals; Arterial Occlusive Diseases; Blotting, Northern; Cluster Analysis; Diterpenes; Epoxy Compounds; Gene Expression Profiling; Gene Expression Regulation; Hemodynamics; Hypertension, Pulmonary; Longitudinal Studies; Male; Monocrotaline; Phenanthrenes; Pneumonectomy; Pulmonary Artery; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors; Transcription, Genetic; Tunica Intima

Topics: Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Diterpenes; Epoxy Compounds; Humans; Hypertension, Pulmonary; Immunosuppressive Agents; Phenanthrenes; Rats; Transforming Growth Factor beta

This paper reports the effect of triptolide (a diterpenoid triepoxide) on the development of monocrotaline (MCT)-induced pulmonary hypertension in pneumonectomized rats. Male Sprague- Dawley rats were injected with MCT (60 mg/kg) on Day 7 after left pneumonectomy. Rats received therapy from Day 5 to 35 with triptolide (0.25 mg/kg intraperitoneally, every other day, n = 10), or vehicle (0.1 ml of ethanol/cremophor intraperitoneally, every other day, n = 10). By Day 35, triptolide-treated rats demonstrated lower mean pulmonary arterial pressure (mPAP) than vehicle-treated rats (mPAP 21 +/- 3 versus 42 +/- 5 mm Hg, p < 0.001). Triptolide-treated rats also had significantly less right ventricular hypertrophy (RVH) and pulmonary arterial neointimal formation. In a rescue experiment, rats initiated therapy on Day 21. At Day 35, vehicle-treated rats (n = 4) had higher mPAP (40 +/- 9 mm Hg), greater RVH, and more severe pulmonary arterial neointimal formation than rats that received triptolide (0.25 mg/kg every other day, n = 7, mPAP 30 +/- 4 mm Hg) and rats that received triptolide (0.2 mg/kg daily, n = 7, mPAP 25 +/- 5 mm Hg, p < 0.01). In pneumonectomized rats that receive MCT, triptolide attenuates the development of pulmonary hypertension and RVH, and promotes regression of pulmonary arterial neointimal formation.

Topics: Analysis of Variance; Animals; Disease Models, Animal; Diterpenes; Drug Evaluation, Preclinical; Epoxy Compounds; Hemodynamics; Hypertension, Pulmonary; Immunosuppressive Agents; Male; Monocrotaline; Neovascularization, Pathologic; Phenanthrenes; Pneumonectomy; Rats; Rats, Sprague-Dawley; Specific Pathogen-Free Organisms; Time Factors; Tunica Intima