Arterial Hypertension In Rats Research Articles

Effect of atorvastatin on pulmonary arterial hypertension in rats through PI3K/AKT signaling pathway.

The aim of this study was to investigate the effect of atorvastatin on pulmonary arterial hypertension (PAH) in rats and to observe its specific regulatory mechanism through the phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/AKT) signaling pathway. The model of PAH was successfully established in rats via hypoxia feeding. All rats were divided into three groups, including Control group (n=15), PAH model group (Model group, n=15) and atorvastatin treatment group (Ator group, n=15). Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nitric oxide (NO) were detected via enzyme-linked immunosorbent assay (ELISA). Right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) in each group were determined as well. Meanwhile, the pathological changes in lung tissues of rats were detected via hematoxylin-eosin (HE) staining. Furthermore, the apoptosis level of lung tissues in each group was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. In addition, the expression levels of PI3K/AKT signaling pathway and apoptotic genes in lung tissues were detected via quantitative Polymerase Chain Reaction (qPCR). In Model group, the levels of TNF-α and IL-6 increased significantly, while the level of NO decreased. Both RVSP and RVHI in Model group were significantly higher than those of Control group and Ator group (p<0.05). The results of HE staining revealed that Model group showed significantly severe lung tissue injury (p<0.05). According to the results of TUNEL staining, the number of apoptotic cells in lung tissues in Model group was significantly smaller than that of Ator group (p<0.05). Meanwhile, the expression level of cysteinyl aspartate-specific proteinase-3 (Caspase-3) in Model group was markedly lower than that of Ator group (p<0.05). However, the expression level of B-cell lymphoma-2 (Bcl-2) in Model group was markedly higher than that of Ator group (p<0.05). In Ator group, the expression levels of PI3K and AKT in lung tissues were remarkably higher than those of Model group (p<0.05). All the above results indicated that atorvastatin could effectively up-regulate the expressions of PI3K and AKT (p<0.05). Atorvastatin regulates the symptoms of PAH in rats through activating the PI3K/AKT signaling pathway.

Effects of masitinib compared with tadalafil for the treatment of monocrotaline-induced pulmonary arterial hypertension in rats

Targeting vascular remodeling in pulmonary arterial hypertension (PAH) remains a challenge given the lack of potent anti-remodeling abilities of the therapeutic drugs. Although sildenafil has been shown to ameliorate cardiopulmonary remodeling, that of tadalafil is questionable. Masitinib, a tyrosine kinase inhibitor appears safer and more potent than imatinib for treatment of malignancies, but its efficacy on PAH is unknown. Therefore, we investigated the anti-remodeling properties of masitinib (5, 15, 50 mg/kg) and tadalafil (5, 10 mg/kg) using a monocrotaline-induced rat model of PAH. The 14-day treatment with masitinib (15, 50 mg/kg) resulted in significantly decreased right ventricular (RV) systolic pressure (RVSP) and hypertrophy (RVH), and pulmonary vascular remodeling, whereas tadalafil showed weaker anti-remodeling properties. Besides, masitinib significantly blocked the mitogen-associated protein kinase (MAPK) pathway, and reduced phosphodiesterase (PDE)-5 mRNA expression in the lungs. By contrast, tadalafil did not significantly inhibit the MAPK pathway. Further, the 28-day treatment extension revealed that masitinib-treated rats (15 mg/kg) had significantly lower RVSP, and higher heart rate and serum cyclic guanosine monophosphate (cGMP) level, whereas those treated with tadalafil (10 mg/kg) showed insignificantly lower RVSP and higher cGMP level. Moreover, the RVH indices, heart rates, body weight gains, and survival rates of rats in both groups were comparable. Collectively, these results suggest that the treatment with a low-dose masitinib was non-inferior than tadalafil. A lower dose of masitinib may represent a novel approach to target both the cardiopulmonary remodeling and the dysregulated vasoconstriction in PAH.

Echocardiographic evaluation of monocrotaline induced pulmonary arterial hypertension in rats

Objective To analyze the correlation between the direct measurement of pulmonary artery pressure and the related echocardiographic parameters in rats with pulmonary arterial hypertension (PAH), and establish a predictable equation for pulmonary artery pressure using non-invasive ultrasonic parameters. Methods Fifteen male Wistar rats were randomly divided into normal control (NC) group with five rats and PAH model group with 10 rats.PAH model was established by intraperitoneal injection of 1% MCT solution in the dose of 60 mg/kg. All the rats were examined by ultrasonic apparatus to record cardiac parameters including right ventricle anterior wall thickness (RVAWT), pulmonary artery diameter (PAD), aorta diameter (AOD), pulmonary artery acceleration time (PAAT), pulmonary artery ejection time (PAET), right ventricle end-diastolic diameter (RVEDD), right ventricle end-diastolic length (RVEDL), tricuspid annular plane systolic excursion (TAPSE) and left ventricular ejection fraction(LVEF) before experiments as well as 2 and 4 weeks after modeling. At the fifth week of modeling, all the rats were administrated with thoracotomy and right ventricular catheter to obtain pulmonary artery systolic, diastolic and mean pressures (PASP, PADP and PAMP). Results As time went on, measures of RVAWT, PAD, PAD/AOD, RVEDD, RVEDL, RVEDD/RVEDL increased, while measurements of PAAT, PAAT/PAET, TAPSE decreased in the model group.The changes of RVAWT, PAD, PAAT/PAET, RVEDD in the model group appeared early in the second week in contrast to data before molding (P<0.05). When comparing model group with NC group, there were statistic differences of RVAWT, PAAT/PAET as early as 2 weeks after modeling measuring (all P<0.05) and the dramatic variance in the parameters of PAD/AOD, PAAT, RVEDD, RVEDD/RVEDL, TAPSE appeared in 4-week observation. Correlation analysis suggested there were high-degree correlations between PAAT, PAAT/PAET and PASP, PAMP (for PASP: r=-0.829, -0.865, P<0.05; for PAMP: r=-0.831, -0.842, P<0.05), and moderate-degree correlations between RVAWT, PAD/AOD, RVEDD, RVEDD/RVEDL, TAPSE and PASP, PAMP (for PASP: |r|=0.615-0.786, P<0.05; for PAMP: r=0.683-0.799, P<0.05). The linear dependent equations were established as PASP=-169.392PAAT/PAET+ 105.092 (r2=0.748, P=0.000), PASP=49.576RVAWT+ 67.314RVEDD/RVEDL-45.198 (r2=0.731, P=0.003), PAMP=-150.664PAAT/PAET+ 88.156 (r2=0.709, P=0.001), PAMP=37.988RVAWT+ 82.072RVEDD/RVEDL-50.517 (r2=0.794, P=0.001) to represent the relationships between PASP or PAMP and PAAT/PAET or RVAWTcombined RVEDD/RVEDL. Conclusions Echocardiography can monitor changes in heart structure and hemodynamics.Ultrasonic parameters especially PAAT/PAET or RVAWT, RVEDD/RVEDL could be used to estimate PASP or PAMP measured by catheterization. Key words: Echocardiography; Hypertension, pulmonary; Monocrotaline; Rat

DL0108 suppresses the development of pulmonary arterial hypertension in rats through its protective effect on pulmonary arteries

BackgroundPulmonary arterial hypertension (PAH) is a severe disease but in short of an effective drug. DL0108 is a flavonoid discovered by our lab, and is recently found useful in the treatment of PAH. The present study aims to evaluate the potency of DL0108 in PAH rats induced by monocrotaline (MCT).MethodThe PAH rat model was established by subcutaneous injection of 50 mg/kg MCT on day 0. From the second day, 3, 10, or 30 mg/kg DL0108 was respectively administrated (i.p.) daily for 4 weeks in three tested groups, while the model and control group were treated with normal saline. During the experiment, the survival rate and body weight were recorded. At the end of the study, the right ventricular systolic pressure (RVSP) was measured through right cardiac catheterization. The heart ventricle was isolated to calculate the Fulton index (RV/LV+S). The contraction and relaxation of pulmonary artery rings were tested in a classical isolated vessel experiment.ResultOn day 28, the survival rate of the model group was 66.7%. Treatment with 3, 10, or 30 mg/kg DL0108 increased the survival rate to 73.3%, 86.7% and 86.7%, respectively. However, the decrease of body weight induced by PAH was not improved by DL0108. The RVSP of PAH rats in the model group increased from 21.73 to 49.61 mmHg, while the treatment with DL0108 reduced the RVSP to 30.56, 27.42 or 24.9 mmHg, respectively. Meanwhile, DL0108 significantly reduced the right ventricular hypertrophy in a dose‐dependent manner. In the isolated vessel experiment, it was found that 3 and 10 mg/kg DL0108 improved the contraction response of pulmonary artery rings to 10−6 M phenylephrine and the relaxant effect induced by the accumulation of acetylcholine (10−8–10−4 M Ach).ConclusionEarly intervention of PAH rats with DL0108 can delay the progression of the disease and increase the survival rate. The preliminary study indicates that DL0108 protects the function of pulmonary arteries, relieves the remodeling of vessels to control the pressure, and in turn attenuates the injury of heart ventricle. This study contributes to the further development of DL0108 for the treatment of PAH.Support or Funding InformationThis project was supported by grants from the Nation Natural Science Foundation of China (No. 81603101, 81773935, 81573645), Natural Science Foundation of Beijing (No. 7174322) and CAMS Innovation Fund for Medical Sciences (2016‐I2M‐1‐010, 2017‐I2M‐1‐010). The survival rates of PAH rats treated by DL0108.imageThe survival rates of PAH rats treated by DL0108.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effect of estrogen on right ventricular remodeling of monocrotaline-induced pulmonary arterial hypertension in rats and its mechanism.

To elucidate the effect of estrogen on right ventricular remodeling of pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT) in rats and its underlying mechanism. Male Sprague- Dawley (SD) rats were adaptively fed for one week, and then, randomly divided into control group, MCT group, MCT+17-β estradiol (50 mg·kg-1·d-1) group, and MCT+17-β estradiol (100 mg·kg-1·d-1) group, with 8 rats in each group. PAH rat model was constructed by subcutaneous injection of 60 mg·kg-1 MCT for consecutive 4 weeks. The right external jugular vein was intubated to monitor rat RVSP (right ventricular systolic pressure) and mPAP (mean pulmonary arterial pressure). After animal procedures, RV (right ventricle) and LV+S (left ventricle+ventricular septum) of rat were harvested and weighed. Rat tibia was collected and recorded for its length, followed by calculation of RV/(LV+S) and RV/length of the tibia. HE staining and Masson staining were conducted to observe the pathological change and collagen deposition in RV, respectively. RV was prepared for homogenate, followed by detection of total antioxidant capacity (T-AOC) and malondialdehyde (MDA) activities. Expression levels of collagen I, collagen III, NOX4, and NF-κB in RV of PAH rats were detected by qRT-PCR and Western blot. Lower RVSP, mPAP, RV/(LV+S) and RV/length of the tibia were observed in rats of MCT+17-β estradiol (50 mg·kg-1·d-1) group and MCT+17-β estradiol (100 mg·kg-1·d-1) group compared with those of MCT group. Injection of 17-β estradiol (50 mg·kg-1·d-1 and 100 mg·kg-1·d-1) in PAH rats remarkably alleviated pathological changes and collagen deposition in RV. T-AOC activity increased, whereas MDA activity decreased in PAH rats injected with 17-β estradiol. Expression levels of collagen I, collagen III, NOX4, and NF-κB in RV of PAH rats were all downregulated by 17-β estradiol treatment. 17-β estradiol could remarkably alleviate MCT-induced right ventricular remodeling of PAH rats. It is suggested that 17-β estradiol exerts its protective role in PAH by inhibiting NOX4-mediated oxidative stress and NF-κB-mediated collagen deposition.

Arctigenin prevents monocrotaline-induced pulmonary arterial hypertension in rats.

The hallmark features of the development of pulmonary arterial hypertension (PAH) include the proliferation of pulmonary vascular smooth muscle cells, oxidative stress, inflammation, and pulmonary artery remodeling. Arctigenin is a bioactive component of Arctium lappa that exerts anti-inflammatory and antiproliferative effects in several diseases; however, its effects on pulmonary arteries are still unclear. This study aimed to investigate the efficacy of arctigenin to prevent PAH. Rats injected with monocrotaline (MCT) progressively developed PAH. Arctigenin treatment (50 mg per kg per day, intra-peritoneally) ameliorated right ventricular systolic pressure and pulmonary arterial remodeling, decreased the expression of inflammatory cytokines, and limited the proliferation of pulmonary vascular smooth muscle cells in lungs. Mechanistically, arctigenin effectively inhibited the MCT-induced elevation of NLRP3, caspase-1, and interleukin 1-beta expression in the lungs. These results indicate that arctigenin ameliorates MCT-induced PAH, at least in part, through exerting its anti-inflammatory, antioxidant, and antiproliferative effects, which inhibit the NLRP3 inflammasome signal pathway in rats.

Nanoparticle-Mediated Targeting of Pitavastatin to Small Pulmonary Arteries and Leukocytes by Intravenous Administration Attenuates the Progression of Monocrotaline-Induced Established Pulmonary Arterial Hypertension in Rats.

Statins are known to improve pulmonary arterial hypertension (PAH) by their anti-inflammatory and anti-proliferative effects in animal models. However, recent clinical studies have reported that clinically approved statin doses failed to improve clinical outcomes in patients with PAH. We therefore hypothesized that nanoparticle (NP) -mediated targeting of pitavastatin could attenuate the progression of established PAH.We induced PAH by subcutaneously injecting monocrotaline (MCT) in Sprague-Dawley rats. On day 14 after the MCT injection, animals that displayed established PAH on echocardiography were included. On day 17, they were randomly assigned to the following 5 groups: daily intravenous administration of (1) vehicle, (2) fluorescein-isothiocyanate-NP, (3) pitavastatin, (4) pitavastatin-NP, or (5) oral sildenafil. Intravenous NP was selectively delivered to small pulmonary arteries and circulating CD11b-positive leukocytes. On day 21, pitavastatin-NP attenuated the progression of PAH at lower doses than pitavastatin alone. This was associated with the inhibition of monocyte-mediated inflammation, proliferation, and remodeling of the pulmonary arteries. Interestingly, sildenafil attenuated the development of PAH, but had no effects on inflammation or remodeling of the pulmonary arteries. In separate experiments, only treatment with pitavastatin-NP reduced the mortality rate at day 35.NP-mediated targeting of pitavastatin to small pulmonary arteries and leukocytes attenuated the progression of established MCT-induced PAH and improved survival. Therapeutically, pitavastatin-NP was associated with anti-inflammatory and anti-proliferative effects on small pulmonary arteries, which was completely distinct from the vasodilatory effect of sildenafil. Pitavastatin-NP can be a novel therapeutic modality for PAH.

Magnolol ameliorates pneumonectomy and monocrotaline-induced pulmonary arterial hypertension in rats through inhibition of angiotensin II and endothelin-1 expression

Background: Magnolol, a major bioactive component extracted from Magnolia officinalis, exerts several beneficial effects, such as anti-inflammatory and anti-hypertensive activities.Purpose: In this study, we investigated whether magnolol has a protective effect on pneumonectomy and monocrotaline-induced pulmonary arterial hypertension (PAH) in rats.Design/Methods: The alterations of right ventricular (RV) hypertrophy, pulmonary vascular remodeling, histopathological parameters, and related gene expression and signaling pathways in lungs by magnolol treatment were studied in the PAH rats.Results: Administration of magnolol greatly ameliorated the characteristic features of PAH, including increased pulmonary arterial pressure, RV hypertrophy, and pulmonary vascular remodeling. Moreover, magnolol inhibited angiotensin-converting enzyme (ACE)/angiotensin II (Ang II)/Ang II type 1 receptor (AT-1R) cascade, whereas upregulates ACE2 in the lungs of PAH rats. The overexpression of endothelin-1 (ET-1) and ETA receptor occurred in the PAH rats was significantly attenuated by magnolol through inhibition of Akt/ERK1/2/GSK3β/β-catenin pathway. Compared with that of untreated PAH rats, higher expression of endothelial nitric oxide synthase, and lower expression of inducible nitric oxide synthase and O2− production in lungs were observed in magnolol-treated PAH rats.Conclusion: We demonstrated that treatment with magnolol reduces the development of PAH induced by pneumonectomy and monocrotaline in rats, and suppressing Ang II and ET-1-mediated processes may contribute to its protective effects. These findings suggest that magnolol may be a potential agent for PAH therapy.

Bone Marrow-Derived Endothelial Progenitor Cells Contribute to Monocrotaline-Induced Pulmonary Arterial Hypertension in Rats via Inhibition of Store-Operated Ca2+ Channels.

Purpose This study aimed to explore whether bone marrow- (BM-) derived endothelial progenitor cells (EPCs) contributing to monocrotaline- (MCT-) induced pulmonary arterial hypertension (PAH) in rats via modulating store-operated Ca2+ channels (SOC). Methods Sprague Dawley (SD) rats were assigned into MCT group (n = 30) and control group (n = 20). Rats in MCT group were subcutaneously administered with 60 mg/kg MCT solution, and rats in control group were injected with equal amount of vehicle. After 3 weeks of treatment, right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) of two groups were measured, and BM-derived EPCs were isolated. Immunochemistry identification and vasculogenesis detection of EPCs were then performed. [Ca2+]cyt measurement was performed to detect store-operated calcium entry (SOCE) in two groups, followed by determination of Orai and canonical transient receptor potential (TRPC) channels expression. Results After 3 weeks of treatment, there were significant increases in RVSP and RVHI in MCT group compared with control group, indicating that MCT successfully induced PAH in rats. Moreover, the SOCE ([Ca2+]cyt rise) in BM-derived EPCs of MCT group was lower than that of control group. Furthermore, the expression levels of Orai3, TRPC1, TRPC3, and TRPC6 in BM-derived EPCs were decreased in MCT group in comparison with control group. Conclusions The SOC activities were inhibited in BM-derived EPCs of MCT-treated rats. These results may be associated with the depressed expression of Orai3, TRPC1, TRPC3, and TRPC6, which are major mediators of SOC.

Inhibition of Shp2 ameliorates monocrotaline-induced pulmonary arterial hypertension in rats

BackgroundSrc homology 2 containing protein tyrosine phosphatase (PTP) 2 (Shp2) is a typical tyrosine phosphatase interacting with receptor tyrosine kinase to regulate multiple signaling pathways in diverse pathological processes. Here, we will investigate the effect of Shp2 inhibition on pulmonary arterial hypertension (PAH) in a rat model and its potential cellular and molecular mechanisms underlying.MethodsMonocrotaline (MCT)-induced PAH rat model was used in this study. Phps-1, a highly selective inhibitor for Shp2, was administered from 21 days to 35 days after MCT single-injection. Microcatheter method was applied to detected hemodynamic parameters. Histological methods were used to determine PVR changes in PAH rats. Moreover, cultured pulmonary artery smooth muscle cells (PASMCs) treated by platelet-derived growth factor (PDGF) with or without Phps-1 was used to investigate the potential cellular and molecular mechanisms underlying in vitro.ResultsInhibition of Shp2 significantly attenuated MCT-induced increases of mean pulmonary arterial pressure (mPAP), right ventricular systolic pressure (RVSP) and right ventricular hypertrophy (RVH) in rats. Shp2 inhibition effectively decreased thickening of pulmonary artery media and cardiomyocyte hypertrophy as well as perivascular and myocardial fibrosis in MCT-treated rats. Moreover, Shp2 inhibition ameliorated muscularization of pulmonary arterioles in MCT-induced PAH rats. Shp2 inhibition significantly reduced platelet-derived growth factor (PDGF)-triggered proliferation and migration of human pulmonary artery smooth muscle cells (PASMCs), which might be attributed to the inactivations of Akt and Stat3 pathways.ConclusionsShp2 contributes to the development of PAH in rats, which might be a potential target for the treatment of PAH.

Betaine Attenuates Monocrotaline-Induced Pulmonary Arterial Hypertension in Rats via Inhibiting Inflammatory Response.

Background: Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary vascular resistance, leading to right ventricular failure and death. Recent studies have suggested that chronic inflammatory processes are involved in the pathogenesis of PAH. Several studies have demonstrated that betaine possesses outstanding anti-inflammatory effects. However, whether betaine exerts protective effects on PAH by inhibiting inflammatory responses in the lungs needs to be explored. To test our hypothesis, we aimed to investigate the effects of betaine on monocrotaline-induced PAH in rats and attempted to further clarify the possible mechanisms. Methods: PAH was induced by monocrotaline (50 mg/kg) and oral administration of betaine (100, 200, and 400 mg/kg/day). The mean pulmonary arterial pressure, right ventricular systolic pressure, and right ventricle hypertrophy index were used to evaluate the development of PAH. Hematoxylin and eosin staining and Masson staining were performed to measure the extents of vascular remodeling and proliferation in fibrous tissue. Monocyte chemoattractant protein-1 (MCP-1) and endothelin-1 (ET-1) were also detected by immunohistochemical staining. Nuclear factor-κB (NF-κB), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) were assessed by Western blot. Results: This study showed that betaine improved the abnormalities in right ventricular systolic pressure, mean pulmonary arterial pressure, right ventricle hypertrophy index, and pulmonary arterial remodeling induced by monocrotaline compared with the PAH group. The levels of MCP-1 and ET-1 also decreased. Western blot indicated that the protein expression levels of NF-κB, TNF-α, and IL-1β significantly decreased (p < 0.01). Conclusion: Our study demonstrated that betaine attenuated PAH through its anti-inflammatory effects. Hence, the present data may offer novel targets and promising pharmacological perspectives for treating monocrotaline-induced PAH.

Cystamine slows but not inverses the progression of monocrotaline-induced pulmonary arterial hypertension in rats.

Tissue transglutaminase (TG2) plays an important role in pulmonary arterial hypertension (PAH). Previous research indicate that TG2 and protein serotonylation catalyzed by TG2 are upregulated in PAH. Serotonin transporter inhibitor fluoxetine ameliorates PAH via inhibition of protein serotonylation. It is still unknown whether PAH is inhibited through direct inhibition of TG2. Therefore, the present study aimed to investigate the effects of TG2 inhibitor cystamine on monocrotaline-induced PAH in rats. Rats were treated with monocrotaline (60 mg·kg-1, i.p.) in combination with or without cystamine (20, 40 mg·kg-1·day-1, p.o.). The results showed that compared with monocrotaline alone, combination of monocrotaline with cystamine (40 mg·kg-1·day-1, p.o.) relieved right ventricle hypertrophy, inhibited pulmonary arteriolar remodeling, and downregulated protein expression of TG2, phosphorylated protein kinase B (Akt), and extracellular regulated protein kinase (ERK) at day 21. However, except for TG2 expression, these changes were not significantly inhibited by cystamine at day 35. In addition, cystamine dose-dependently enhanced the survival rate of rats injected with monocrotaline at day 35. The findings suggest that cystamine slows but not reverses monocrotaline-induced PAH in rats, which was largely associated with the inhibition of TG2 protein expression and Akt and ERK activation.

Role of vascular ferrochelatase deregulation in the progression of monocrotaline‐induced pulmonary arterial hypertension in rats

Ferrochelatase is a redox sensitive mitochondrial enzyme that is prone to deregulation under many conditions, giving way to a number of diseases. These diseases may involve the altered/decreased production of heme or the overproduction of Zinc Protoporphyrin IX (ZnPPIX), which is a competitive inhibitor of both heme oxygenase‐1 (HO‐1) and soluble guanylate cyclase (sGC). In this study, we aim to characterize the role of ferrochelatase deregulation in pulmonary arterial hypertension (PAH). In order to evaluate ZnPPIX as a possible contributor to PAH, we employed HPLC analysis of isolated small pulmonary arteries from monocrotaline (MCT)‐induced PAH rats, in which we quantified the ZnPPIX content. Our data suggests a decrease in ZnPPIX, which is reflective of a decrease of ferrochelatase activity and/or expression which overrides a possible iron deficiency mechanism as a principle contributor to PAH. Our study may provide some insight into the progression of PAH, highlighting possible future therapeutic targets.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The effects of middle frequency electrical stimulation on mitochondrial dysfunction and capillary regression in soleus muscle with monocrotaline-induced pulmonary arterial hypertension in rats

The effects of middle frequency electrical stimulation on mitochondrial dysfunction and capillary regression in soleus muscle with monocrotaline-induced pulmonary arterial hypertension in rats

A novel p38-alpha MAPK inhibitor (LASSBio-1824) reverses Sugen/Hypoxia-induced pulmonary arterial hypertension in rats

A novel p38-alpha MAPK inhibitor (LASSBio-1824) reverses Sugen/Hypoxia-induced pulmonary arterial hypertension in rats

Ethyl 4-(4′-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate Prevents Progression of Monocrotaline-induced Pulmonary Arterial Hypertension in Rats

&lt;p&gt;Therapies to prevent onset and progression of pulmonary arterial pressure are not very effective yet. This study was designed to investigate the effects of a novel dihydropyrimidinone, ethyl 4-(4′-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate (H-DHPM) on pathogenesis of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). For the same purpose, rats were injected intraperitoneally (i.p.) a single dose (60 mg/kg) of MCT which led to development of PAH in 21 days. MCT insult caused high mortality, pulmonary vascular and parenchymal remodelling. Since the course of PAH pathogenesis is characterised by an early onset and progression phases, H-DHPM was administered i.p. at 30 mg/kg dosage in MCT pre-injected animals either from day 0 through day 21 or day 14 though day 21 of MCT injection in two separate treatment groups. H-DHPM significantly improved survival, prevented remodelling of pulmonary vasculature and parenchyma and subsequently ameliorated PAH pathogenesis. Moreover, we observed significant decrease in right ventricle hypertrophy, measured by wet weight of right ventricle (RV) divided by wet weight of left ventricle plus septum (LV+S), in H-DHPM treated groups as compared to MCT injected animals. These findings suggest H-DHPM not only prevented development of PAH but also treated the PAH pathogenesis in progressive phase. In conclusion, our data determines H-DHPM, might be a future drug for the prevention of PAH.&lt;/p&gt;

Dihydromyricetin prevents monocrotaline-induced pulmonary arterial hypertension in rats

Pulmonary artery hypertension (PAH) is a chronic and deadly disease, for which effective medical treatments are lacking. Here, we investigated whether 2R,3R-dihydromyricetin (DHM) could prevent monocrotaline (MCT)-induced PAH in rats. The MCT-injected rats were treated with normal saline or DHM (100mg/kg body weight/d) for 4 weeks, followed by measurements of right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), pulmonary arterial remodeling (PAR), and expression levels of IL-6, TNF-α, and IL-10. In vitro, we assessed the role of DHM on IL-6-induced migration of primary human pulmonary arterial smooth muscle cells (HPASMCs). We found that DHM treatment attenuated changes in RVSP, RVHI, and PAR in MCT-injected PAH rats. The observed increase of IL-6 levels in PAH rats was inhibited by DHM treatment. In vitro, DHM pretreatment reduced IL-6-induced HPASMC migration. Furthermore, MCT- and IL-6-mediated increases in MMP9 and P-STAT3 (tyr705) PY-STAT3 levels were suppressed by DHM treatment in vivo and in vitro. These results suggest that DHM could prevent MCT-induced rat PAH and IL-6-induced HPASMC migration through a mechanism involving inhibiting of the STAT3/MMP9 axis.

Combination treatment of adipose-derived stem cells and adiponectin attenuates pulmonary arterial hypertension in rats by inhibiting pulmonary arterial smooth muscle cell proliferation and regulating the AMPK/BMP/Smad pathway.

The present study aimed to assess the effects of therapy with adiponectin (APN) gene-modified adipose-derived stem cells (ADSCs) on pulmonary arterial hypertension (PAH) in rats and the underlying cellular and molecular mechanisms. ADSCs were successfully isolated from the rats and characterized. ADSCs were effectively infected with the green fluorescent protein (GFP)-empty (ADSCs-V) or the APN-GFP (ADSCs-APN) lentivirus and the APN expression was evaluated by ELISA. Sprague-Dawley rats were administered monocrotaline (MCT) to develop PAH. The rats were treated with MCT, ADSCs, ADSCs-V and ADSCs-APN. Then ADSCs-APN in the lung were investigated by confocal laser scanning microscopy and western blot analysis. Engrafted ADSCs in the lung were located around the vessels. Mean pulmonary arterial pressure (mPAP) and the right ventricular hypertrophy index (RVHI) in the ADSCs-APN-treated mice were significantly decreased as compared with the ADSCs and ADSCs-V treatments. Pulmonary vascular remodeling was assessed. Right ventricular (RV) function was evaluated by echocardiography. We found that pulmonary vascular remodeling and the parameters of RV function were extensively improved after ADSCs-APN treatment when compared with ADSCs and ADSCs-V treatment. Pulmonary artery smooth muscle cells (PASMCs) were isolated from the PAH rats. The antiproliferative effect of APN on PASMCs was assayed by Cell Counting Kit-8. The influence of APN and specific inhibitors on the levels of bone morphogenetic protein (BMP), adenosine monophosphate activated protein kinase (AMPK), and small mothers against decapentaplegia (Smad) pathways was detected by western blot analysis. We found that APN suppressed the proliferation of PASMCs isolated from the PAH rats by regulating the AMPK/BMP/Smad pathway. This effect was weakened by addition of the AMPK inhibitor (compound C) and BMP2 inhibitor (noggin). Therefore, combination treatment with ADSCs and APN effectively attenuated PAH in rats by inhibiting PASMC proliferation and regulating the AMPK/BMP/Smad pathway.

Expression of key enzymes in the mevalonate pathway are altered in monocrotaline-induced pulmonary arterial hypertension in rats.

Pulmonary arterial hypertension (PAH) is a serious pulmonary vascular disease. The changes in the structure, function and metabolism of endothelial cells are some of the important features of PAH. Previous studies have demonstrated that the mevalonate pathway is important in cardiovascular remodeling. However, whether the mevalonate pathway is involved in the development of PAH remains to be elucidated. The present study aimed to investigate the expression pattern of mevalonate pathway-related enzymes in monocrotaline (MCT)-induced PAH. F344 rats were randomly divided into two groups (n=6/group): Control group rats were injected with a single dose of saline, and MCT group rats were injected with a single dose of MCT (60mg/kg). After 4weeks, the right ventricular systolic pressure (RVSP) was measured, and lung and pulmonary artery tissue samples were collected. It was demonstrated that the RVSP increased and pulmonary vascular remodeling was detected in the PAH group. The expression levels of the enzymes farnesyldiphosphate synthase farnesyltransferase α and geranylgeranyltransferase typeI increased in the PAH group, which suggested that the mevalonate pathway may be involved in the pathological development of PAH.

Ataxia-Telangiectasia Mutated (ATM) Protein Signaling Participates in Development of Pulmonary Arterial Hypertension in Rats.

BackgroundPrevious studies revealed physiological and pathogenetic similarity between vascular smooth muscles cells with severe pulmonary arterial hypertension and tumors. The DNA damage response was found in both pulmonary arterial hypertension (PAH) cells and tumors. The ataxia-telangiectasia mutated proteins (ATM) pathway is considered an important factor in the DNA damage response of tumor formation, but its function in the development of PAH remains unknown.Material/MethodsThe Sprague-Dawley rat PAH model was established. Three weeks (Group M1), 5 weeks (Group M2), and 7 weeks (Group M3) after drug injection, pulmonary expression of ATM, Checkpoint kinase 2 (Chk2), P53, and P21 were measured. A section of the lungs from Group M2 was used for pulmonary artery vascular smooth muscles cells (PA-SMCs) isolation and culture. The effect of KU60019 in the proliferation and apoptosis of primary cultured rat PA-SMCs was measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and TdT-mediated dUTP nick-end labeling (TUNEL), respectively.ResultsImmunohistochemistry results show that the expression of ATM, Chk2, and P21 increased in Groups M1 and M2, and decreased in Group M3. Additionally, expression of P53 increased in Group M1, and decreased in Groups M2 and M3. RT-PCR and Western blotting demonstrated that in Groups M1 and M2, the expression of ATM, Chk2, P53, and P21 increased, whereas it decreased in Group M3. In cell culture, 0.3 μM and 0.5 μM KU60019 increased the growth of PA-SMCs, and 0.5 μM KU60019 reduced cell apoptosis.ConclusionsExpression of the ATM-Chk2 pathway increased in early stages of PAH formation, but decreased in late stages. In primary cultured PA-SMCs, KU60019 increased cell proliferation and inhibited cell apoptosis.