Mufangji tang ameliorates pulmonary arterial hypertension through improving vascular remodeling,inhibiting inflammatory response and oxidative stress,and inducing apoptosis

Background:Mufangji tang(MFJT)is composed of Ramulus Cinnamomi,Radix Ginseng,Cocculus orbiculatus(Linn.)DC.,and Gypsum.In clinical settings,MFJT has been effectively employed in addressing a range of respiratory disorders,notably including pulmonary arterial hypertension(PAH).However,the mechanism of action of MFJT on PAH remains unknown.Methods:In this study,a monocrotaline-induced PAH rat model was established and treated with MFJT.The therapeutic effects of MFJT on PAH rat model were evaluated.Network pharmacology was conducted to screen the possible targets for MFJT on PAH,and the molecular docking between the main active components and the core targets was carried out.The key targets identified from network pharmacology were tested.Results:Results showed significant therapeutic effects of MFJT on PAH rat model.Analysis of network pharmacology revealed several potential targets related to apoptosis,inflammation,oxidative stress,and vascular remodeling.Molecular docking showed that the key components were well docked with the core targets.Further experimental validation results that MFJT treatment induced apoptosis(downregulated Bcl-2 levels and upregulated Bax levels in lung tissue),inhibited inflammatory response and oxdative stress(decreased the levels of IL-1β,TNF-α,inducible NOS,and malondialdehyde,and increased the levels of endothelial nitric oxide synthase,nitric oxide,glutathione and superoxide dismutase),reduced the proliferation of pulmonary arterial smooth muscle cells(downregulated ET-1 andβ-catenin levels and ERK1/2 phosphorylation,increased GSK3βlevels).Conclusion:Our study revealed MFJT treatment could alleviate PAH in rats via induction of apoptosis,inhibition of inflammation and oxidative stress,and the prevention of vascular remodeling.

Risk Stratification and Prognosis of Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Background:Current guidelines for managing pulmonary arterial hypertension(PAH)recommend a risk strati-fication approach.However,the applicability and accuracy of these strategies for PAH associated with congenital heart disease(PAH-CHD)require further validation.This study aims to validate the reliability and predictive accuracy of a simplified stratification strategy for PAH-CHD patients over a three-year follow-up.Additionally,new prognostic variables are identified and novel risk stratification methods are developed for assessing and managing PAH-CHD patients.Methods:This retrospective study included 126 PAH-CHD patients.Clinical and biochemical variables across risk groups were assessed using Kruskal-Wallis and Fisher’s exact tests.Indepen-dent risk factors were identified using ordered logistic regression,while Kaplan-Meier and Cox proportional hazards regression analyses evaluated their impact on all-cause mortality.A new stratification model for the PAH-CHD population was constructed based on these analyses.Results:Significant survival differences across stratified risk groups were observed(p<0.001),validating the effectiveness of the simplified risk stratification method in PAH-CHD patients.Prothrombin activity was a strong independent predictor of adverse outcomes of PAH-CHD patients(Hazard ratio 0.95,p<0.001,C-index 0.70).A model combining N-terminal pro-brain natriuretic peptide,prothrombin activity,albumin,and right atrial area achieved an area under the curve of 0.89 and a C-index of 0.85.Conclusions:The simplified risk stratification method is applicable to PAH-CHD patients.Prothrombin activity is a strong independent predictor of adverse outcomes.A comprehensive risk stratification approach,incorporating both established and novel biomarkers,enhances accessibility and offers predictive efficacy during follow-up for PAH-CHD patients,comparable to established models.

Pulmonary arterial hypertension confirmed by right heart catheterization following COVID-19 pneumonia: A case report and review of literature

BACKGROUND Pulmonary arterial hypertension(PAH)is a disease of the arterioles resulting in an increased resistance in pulmonary circulation with associated high pressures in the pulmonary arteries,causing irreversible remodeling of the pulmonary arterial walls.Coronavirus disease 2019(COVID-19)has been associated with development of new onset PAH in the literature leading to symptoms of dyspnea,cough and fatigue that persist in spite of resolution of acute COVID-19 infection.However,the majority of these cases of COVID related PAH were diagnosed using echocardiographic data or via right heart catheterization in mechanically ventilated patients.CASE SUMMARY Our case is the first reported case of COVID related PAH diagnosed by right heart catheterization in a non-mechanically ventilated patient.Right heart catheterization has been the gold standard for diagnosis of pulmonary hypertension.Our patient had right heart catheterization four months after her initial COVID-19 infection due to persistent dyspnea.CONCLUSION This revealed new onset PAH that developed following her infection with COVID-19,an emerging sequela of the infection.

Rutaecarpine attenuates monocrotaline-induced pulmonary arterial hypertension in a Sprague-Dawley rat model

Background:Pulmonary arterial hypertension presents with obliterative remodeling of the pulmonary arteries and progressive elevation of pulmonary vascular resistance,which increase the risk of right ventricular failure and death.It has been reported in previous studies that rutaecarpine plays a crucial role in anti-inflammatory and antioxidant activities,which may help regulate cell apoptosis and cell proliferation.The purpose of this study was to determine the effects of rutaecarpine in the rat model of monocrotaline-induced pulmonary hypertension.Methods:We induced pulmonary arterial hypertension in adult Sprague-Dawley rats by injecting monocrotaline(60 mg/kg)and then treated with rutaecarpine(40 mg/kg·d)or sildenafil(30 mg/kg·d)(positive control).Subsequently,pulmonary function,inflammation,cytokines and pulmonary vascular remodeling or proliferation were assessed.Results:Rutaecarpine was found to improve monocrotaline-induced mean pulmonary artery pressure,cardiac index,right heart index,right ventricular hypertrophy index,pulmonary artery remodeling and pulmonary function.reverse transcription-quantitative polymerase chain reaction demonstrated a decrease in tumor necrosis factor-α,interleukin-6 and interleukin-1β,whereas western blots a significantly decrease in the expression of nuclear factor kappa-B,endothelin-1,extracellular signal-regulated kinases 1/2,B cell lymphoma-2,Beclin1 and microtubule-associated protein1 light chain 3-II protein,and increase in the expression of Bax,caspase-3 and p62 protein.Conclusion:Rutaecarpine attenuated pulmonary arterial hypertension by inhibiting inflammation,oxidative stress,cell proliferation and autophagy,while promoting apoptosis.

Inhibitory Effect of PPARδAgonist GW501516 on Proliferation of Hypoxia-induced Pulmonary Arterial Smooth Muscle Cells by Regulating the mTOR Pathway

Objective This study aimed to investigate the effects of the peroxisome proliferator-activated receptorδ(PPARδ)agonist GW501516 on the proliferation of pulmonary artery smooth muscle cells(PASMCs)induced by hypoxia,in order to search for new drugs for the treatment and prevention of pulmonary vascular remodeling.Methods PASMCs were incubated with different concentrations of GW501516(10,30,100 nmol/L)under the hypoxic condition.The proliferation was determined by a CCK-8 assay.The cell cycle progression was analyzed by flow cytometry.The expression of PPARδ,S phase kinase-associated protein 2(Skp2),and cell cycle-dependent kinase inhibitor p27 was detected by Western blotting.Then PASMCs were treated with 100 nmol/L GW501516,100 nmol/L mammalian target of rapamycin(mTOR)inhibitor rapamycin and/or 2µmol/L mTOR activator MHY1485 to explore the molecular mechanisms by which GW501516 reduces the proliferation of PASMCs.Results The presented data demonstrated that hypoxia reduced the expression of PPARδin an oxygen concentration-and time-dependent manner,and GW501516 decreased the proliferation of PASMCs induced by hypoxia by blocking the progression through the G0/G1 to S phase of the cell cycle.In accordance with these findings,GW501516 downregulated Skp2 and upregulated p27 in hypoxia-exposed PASMCs.Further experiments showed that rapamycin had similar effects as GW501516 in inhibiting cell proliferation,arresting the cell cycle,regulating the expression of Skp2 and p27,and inactivating mTOR in hypoxia-exposed PASMCs.Moreover,MHY1485 reversed all the beneficial effects of GW501516 on hypoxia-stimulated PASMCs.Conclusion GW501516 inhibited the proliferation of PASMCs induced by hypoxia through blocking the mTOR/Skp2/p27 signaling pathway.

Iptakalim, a novel ATP-sensitive potassium channel opener, inhibits pulmonary arterial smooth muscle cell proliferation by downregulation of PKC-α

Iptakalim is a new ATP-sensitive potassium （KATp） channel opener, and it inhibits the proliferation of pulmonary arterial smooth muscle cells （PASMCs） and pulmonary vascular remodeling. However, the underlying mechanism remains unclear. In the present study, we found that iptakalim significantly decreased pulmonary artery pressure, inhibited pulmonary ariery remodeling and PKC-α overexpression in chronic hypoxia in a rat pulmonary hypertension model. Iptakalim reduced hypoxia-induced expression of PKC-α, and abolished the effect of hypoxia on PASMC proliferation significantly in a dose-dependent manner in vitro. Moreover, these effects were abol- ished by glibenclamide, a selective KArp channel antagonist. These results indicate that iptakalim inhibits PASMC proliferation and pulmonary vascular remodeling induced by hypoxia through downregulating the expression of PKC-α. Iptakalim can serve as a novel promising treatment for hypoxic pulmonary hypertension.

Selexipag as Add-on Therapy for Patients with Pulmonary Arterial Hypertension Associated with Congenital Heart Disease:A Single-Center Retrospective Study

Purpose:This study examined the efficacy and safety of selexipag in treating pulmonary arterial hypertension(PAH)associated with congenital heart disease(CHD).Materials and Methods:We conducted a retrospective study of patients with CHD-associated PAH,treated with selexipag since December 2017.Thirteen adult patients(mean age,45.4 years;women,77%)were treated with selexipag as add-on therapy.Baseline characteristics,World Health Organization functional class,6-minute walking distance(6MWD)test results,N-terminal pro-B-type natriuretic peptide levels,echocardiographic data,and incidence of side effects were assessed.Results:The majority of patients(12/13,92.3%)experienced more than one treatment-associated complication;one patient dropped out of the study due to intolerable myalgia.The results of 6MWD test(from 299.2±56.2 m to 363.8±86.5 m,p=0.039)and tricuspid regurgitation(TR)pressure gradient(from 84.7±20.5 mmHg to 61.6±24.0 mmHg,p=0.018)improved and remained improved after selexipag treatment in 12 patients.Based on the results of a non-invasive risk assessment,8(66.7%)patients showed improvement,3(25.0%)showed no interval change,and the status of one patient(8.3%)deteriorated.Moreover,compared to patients treated with a low dosage,patients treated with a medium-to-high dosage showed a greater increase in 6MWD results(88.3±26.4 m vs.55.3±27.6 m,p=0.043)and a greater reduction in the TR pressure gradient(-33.7±10.9 mmHg vs.-12.5±12.0 mmHg,p=0.015).Conclusion:Selexipag is an efficient pulmonary vasodilator as add-on therapy in treating CHD-associated PAH.

Perioperative Nursing for Adult Congenital Heart Disease with Severe Pulmonary Arterial Hypertension

Objectives: To explore the main points of perioperative nursing for adult congenital heart disease with severe pulmonary arterial hypertension. Methods: A retrospective study of 13 patients with congenital heart disease and severe pulmonary arterial hypertension who admitted to the perioperative period of care from January 2018 to December 2019. To prevent perioperative complications of the patients, the focus is on respiratory and circulatory system care, followed by blood coagulation monitoring, digestive system protection and psychological care. Results: All 13 patients passed the perioperative period and were discharged from ICU. Conclusion: Adult congenital heart disease with severe pulmonary arterial hypertension has high perioperative risk, respiratory and circulatory system care is the key.

Screening key target genes for pulmonary arterial hypertension based on bioinformatics

Background:Screening key target genes for pulmonary arterial hypertension(PAH)based on bioinformatics to provide a reference for the clinical development of drugs to cure PAH.Methods:The keyword“pulmonary arterial hypertension”was used to search related genes in the National Center for Biotechnology Information database(NCBI).The obtained genes data was input to the database of Database for Annotation,Visualization and Integrated Discovery(DAVID)(Version 6.8)to collect relevant information about pathways and genes.And the data of genes were enriched in 37 pathways and genes with occurrence frequency≥10 were respectively imported into the String database to construct protein-protein interaction(PPI)network diagrams,and the two network diagrams were compared.Results:VEGFA,MAPK1,MAPK3,IL6,JUN and TNF were among the highest-ranked genes in two network diagrams.Conclusion:The pathogenesis of PAH is associated with multiple pathways such as the TGF-βsignaling pathway,PI3K-Akt signaling pathway,MAPK signaling pathway,HIF-1 signaling pathway and so on.The study of VEGFA,MAPK1,MAPK3,IL6,JUN and TNF are closely related to PAH is necessary for us to study further.Through gene interaction network and pathway analysis of disease-associated genes,which will help us to screen the critical target genes of PAH and provide a reference for clinical development of effective drugs for PAH.

Osthole attenuates pulmonary arterial hypertension by modulation of phospholipid metabolism

OBJECTIVE Pulmonary arterial hypertension(PAH)is a malignant pulmonary vascular disease lacking efficacy therapeutics.Therefore,it urgently needs to develop safe and effective drugs for PAH treatment.Osthole derived from Cnidium monnieri(L.)Cusson(Shechuangzi)or Angelica pubescens Maxim(Duhuo)has the capacity to alleviate PAH by decreasing pulmonary arterial pressure and alleviating pulmonary vascular remodeling in rats,which is a candidate drug for the prevention of PAH,but the underlying modulatory mechanism is still unclear.Our study aims at investigating the metabolic modulatory mechanism of osthole against PAH employing functional metabolomics strategy.METHODS PAH model rats were successfully established with MCT,following osthole administration,then functional metabolomics based on untargeted metabolomics assay,targeted lipidomics analysis,qRT-PCR,Western blotting and ELISA were performed to investigate the modulatory mechanism of osthole against pulmonary arterial pressure and pulmonary vascular remodeling in PAH.RESULTS Untargeted metabolomics results found that sphingosine 1-phosphate(S1P)was the differential metabolites characterized PAH and reversed by osthole treatment.S1P is a crucial sphingolipid metabolite catalyzed by sphingosine kinases1(Sphk1)and functions as promoting PASMCs proliferation contributing to pulmonary vascular remodeling and pulmonary arterial pressure increase.We revealed that osthole reversed high level of S1P by modulating metabolic enzyme Sphk1 via inactivating microRNA-21-PI3K/Akt/mTOR signal pathway to decrease pulmonary arterial pressure in rats with PAH.Then,targeted phospholipid metabolomics results uncovered that decadienyl-L-carnitine(C10:2)was the differential metabolite characterized PAH and corrected by osthole treatment in rat with PAH.C10:2 is the intermediate metabolite of fatty acid oxidation(FAO),and C10:2 accumulation indicated mitochondrial dysfunction and FAO increase.CONCLUSION Osthole could block lipid metabolic reprogramming through functional modulating the expression of fatty acid translocase,fatty acid synthase,phospholipase A2,carnitine palmitoyltransferase 1A to inhibit C10:2,thus to improve mitochondrial dysfunction and inhibit utilizing lipid to biosynthesize necessary essence for pulmonary artery smooth muscle cells(PASMCs)proliferation.Moreover,we delineated that C10:2 and metabolic reprogramming enzymes were modulated by miRNA-22-3p which was involved in PASMCs proliferation and pulmonary vascular remodeling.Therefore,osthole inhibited miRNA-22-3p mediated lipid metabolic reprogramming to ameliorate pulmonary vascular remodeling.

Hypoxia promotes cell proliferation by modulating E2F1 in chicken pulmonary arterial smooth muscle cells

In this study,we sought to investigate the expression of the transcription factor E2F1 in chicken pulmonary arterial smooth muscle cells upon hypoxia exposure,as well as the role that E2F1 played in the regulation of cell proliferation.Isolated chicken pulmonary arterial smooth muscle cells were subjected to hypoxia or normoxia for indicated time points.Cell viability,DNA synthesis,cell cycle profile,and expression of E2F1 were analyzed.The results showed that hypoxia promoted cell proliferation and DNA synthesis which was accompanied by an increased S phase entry and upregulation of E2F1 at mRNA and protein levels.Using siRNA technology,we demonstrated that gene inactivation of endogenous E2F1 abolished hypoxia-induced cell proliferation,DNA synthesis,and S phase entry compared with negative siRNA transfected cells.These results suggest that hypoxia-induced proliferation is mediated by inducing E2F1 in chicken pulmonary arterial smooth muscle cells.

Pulmonary arterial hyper-tension in a patient with hereditary hemorrhagic telangiectasia and family gene analysis:A case report

BACKGROUND Hereditary hemorrhagic telangiectasia(HHT)is a rare autosomal dominant genetic disease.Very few patients suffering from HHT present with associated pulmonary arterial hypertension(PAH),which may result in a poor prognosis.Here,we report a case of HHT with PAH.The patient’s clinical manifestations and treatment as well as genetic analysis of family members are reviewed,in order to raise awareness of this multimorbidity.CASE SUMMARY A 45-year-old Chinese woman was admitted to the hospital to address a complaint of intermittent shortness of breath,which had lasted over the past 2 years.She also had a 30-year history of recurrent epistaxis and 5-year history of anemia.She reported that the shortness of breath had aggravated gradually over the 2 years.Physical examination discovered anemia and detected gallop rhythm in the precordium.Chest computerized tomography and cardiac ultrasound demonstrated PAH and hepatic arteriovenous malformation.The formal clinical diagnosis was HHT combined with PAH.The patient was treated with ambrisentan and her condition improved for a time.She died half a year after the diagnosis.Genetic testing revealed the patient and some family members to carry an activin A receptor-like type 1 mutation(c.1232G>A,p.Arg411Gln);the family was thus identified as an HHT family.CONCLUSION We report a novel gene mutation(c.1232G>A,p.Arg411Gln)in a Chinese HHT patient with PAH.

NOTCH3 Mutations and CADASIL Phenotype in Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Background:The etiology of pulmonary arterial hypertension associated with congenital heart disease(PAHCHD)is complicated and the phenotype is heterogeneous.Genetic defects of NOTCH3 were associated withcerebral disease and pulmonary hypertension.However,the relationship between NOTCH3 mutations and theclinical phenotype has not been reported in CHD-PAH.Methods:We eventually enrolled 142 PAH-CHD patientsfrom Fuwai Hospital.Whole exome sequencing(WES)was performed to screen the rare deleterious variants ofNOTCH3 gene.Results:This PAH-CHD cohort included 43(30.3%)men and 99(69.7%)women with the meanage 29.8±10.9 years old.The pathogenic or likely pathogenic mutations of NOTCH3 were identified in five cases.Patients 2,5,8 and 11 carried the same NOTCH3 mutation c.1630C>T(pArg544Cys),which is the hot-spotmutation for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy(CADASIL).Patient 3 carried the NOTCH3 mutation p.Arg75Gln that has also been reported to be associatedwith the CADASIL.Patients 2,5,8,11 took the examination of the cerebral magnetic resonance imaging(MRI)and confirmed the phenotype of CADASIL.Conclusions:We first reported the NOTCH3 rare mutationsand CADASIL phenotypes in CHD-PAH patients.The NOTCH3 rare variants were with a relatively high positiverate and CADASIL phenotypes were likely enriched in PAH-CHD patients.The preoperative neurological examinationmight be recommended for PAH-CHD patients to determine the surgical contraindications and reduceintraoperative neurological complications.

Discharge planning for children with ventricular septal defect and pulmonary arterial hypertension in China

Objective:To evaluate the effectiveness of discharge planning on maternal caring knowledge,maternal caring behavior,maternal discharge readiness and the rehospitalization of children with ventricular septal defect and pulmonary arterial hypertension(VSD-PAH).Background:Children with congenital heart disease(CHD)with pulmonary arterial hypertension(PAH)have more complications after surgery than those without PAH.Discharge planning is an effective strategy to help children leave the hospital safely,and receive appropriate care after discharge.Methods:A quasi-experimental design was used.Sixty children and their mothers were recruited and divided into two groups:the control group received conventional care,the intervention group received both conventional care and additional discharge planning care.Results:(1)After admission,maternal caring knowledge between the two groups was similar.(2)At discharge,maternal discharge readiness,maternal caring knowledge and maternal caring behavior in the intervention group was significantly higher compared to the control group(t=3.35,p=0.001;F=84.74,p<0.001;F=23.82,p<0.001).This difference persisted after discharge,and was evident at one month and three months after discharge.(3)However,no significant difference in the readmission rate of children after discharge was evident between the two groups.Conclusions:Discharge planning improves the maternal discharge readiness,maternal caring knowledge and maternal caring behaviors.However,this planning did not reduce the readmission rate of children with CHD-PAH.

Prognostic value of the echocardiographic right/left ventricular end-diastolic diameter ratio in patients with idiopathic pulmonary arterial hypertension

Background Previous studies have shown that an echocardiographic right/left ventricular end-diastolic diameter ratio(RV/LV ratio)≥0.9 is an independent predictor of poor prognosis in patients with acute pulmonary embolism. The prognostic value of the RV/LV ratio in patients with idiopathic pulmonary arterial hypertension(IPAH) is still unknown. Methods We retrospectively enrolled 95 consecutive patients with newly diagnosed IPAH and 16 of them were reevaluated by echocardiography at 3-12 months following targeted therapy.Follow-up data were obtained by telephone interviews and review of the patients’ records.Results The RV/LV ratio was in parallel with the severity of World Health Orgnization(WHO) functional class and mean right atrial pressure.The RV/LV ratio was positively correlated with total pulmonary resistance(P P P 2 saturation(P P = 0.001),weight and absence of targeted therapy were independent predictors of death.No significant changes in the RV/LV ratio before and after targeted therapy were observed. A baseline RV/LV ratio≥0.84 or a further increase in the RV/LV ratio during targeted therapy indicated a poor prognosis. Conclusions The RV/LV ratio helps to assess the severity of IPAH and serves as an independent predictor of prognosis in patients with IPAH.

Treatment with neurohormonal inhibitors and prognostic outcome in pulmonary arterial hypertension with risk factors for left heart disease

BACKGROUND Despite major advances in pharmacologic treatment,patients with pulmonary arterial hypertension(PAH)still have a considerably reduced life expectancy.In this context,chronic hyperactivity of the neurohormonal axis has been shown to be detrimental in PAH,thus providing novel insights on the role of neurohormonal blockade as a potential therapeutic target.AIM To evaluate the application and prognostic effect of neurohormonal inhibitors(NEUi)in a single-center sample of patients with idiopathic PAH and risk factors for left heart disease.METHODS We analyzed data retrospectively collected from our register of right heart catheterizations performed consecutively from January 1,2005 to October 31,2018.Patients on beta-blocker,angiotensin-converting enzyme inhibitor,angiotensin receptor blocker or mineralocorticoid receptor antagonist at the time of right heart catheterization were classified as NEUi users and compared to NEUi nonrecipients.RESULTS Complete data were available for 57 PAH subjects:27 of those(47.4%)were taking at least one NEUi at the time of right heart catheterization and were compared with the remaining 36 NEUi non-recipients.NEUi users were older and had a higher cardiovascular risk profile compared to non-recipients.Additionally,NEUi non-users had a higher probability of dying during the course of follow-up than NEUi recipients(56.7%vs 25.9%,log-rank P=0.020).CONCLUSION The above data highlighted a subgroup of patients with PAH and comorbidities for left heart disease in which NEUi use has shown to be associated with improved survival.Future prospective studies are needed to identify the most appropriate therapeutic strategies in this subset population.

Treatment of patients with bosentan in postoperation of congenital heart disease with pulmonary arterial hypertension:a double-blind,randomized controlled trial

Objective Endothelin is a key role in the pathogenic of pulmonary arterial hypertension. High concentrations of endothelin 1 have been recorded in plasma and lungs of patients with pulmonary artery hypertension associated with congenital heart disease,and the concentrations of endothelin-1 was correlated with severity degree

Salvianolic acid A attenuates vascular remodeling in a pulmonary arterial hypertension rat model

OBJECTIVE The current therapeutic approaches have a limited effect on the dysregulated pulmonary vascular remodeling,which is characteristic of pulmonary arterial hypertension(PAH).In this study we exam-ined whether salvianolic acid A(SAA)extracted from the traditional Chinese medicine′Dan Shen′attenuated vascular remodeling in a PAH rat model,and elucidated the underlying mechanisms.METHODS PAH was induced in rats by injecting a single dose of monocrotaline(MCT 60 mg·kg-1,sc).The rats were orally treated with either SAA(0.3,1,3 mg·kg-1·d-1)or a positive control bosentan(30 mg·kg-1·d-1)for 4 weeks.Echocardiography and hemodynamic measurements were performed on d 28.Then the hearts and lungs were harvested,the organ indices and pulmonary artery wall thickness were calculated,and biochemical and histochemical analysis were conducted.The levels of apoptotic and signaling proteins in the lungs were measured using immunoblotting.RESULTS Treatment with SAA or bosentan effectively ameliorated MCTinduced pulmonary artery remodeling,pulmonary hemodynamic abnormalities and the subsequent increases of right ventricular systolic pressure(RVSP).Furthermore,the treatments significantly attenuated MCT-induced hypertrophic damage of myocardium,parenchymal injury and collagen deposition in the lungs.Moreover,the treatments attenuated MCT-induced apoptosis and fibrosis in the lungs.The treatments partially restored MCT-induced reductions of bone morphogenetic protein typeⅡreceptor(BMPRⅡ)and phosphorylated Smad1/5 in the lungs.CONCLUSION SAA ameliorates the pulmonary arterial remodeling in MCT-induced PAH rats most likely via activating the BMPRⅡ-Smad pathway and inhibiting apoptosis.Thus,SAA may have therapeutic potential for the patients at high risk of PAH.

DL0805 derivatives protect the pulmonary arterial cells via the RhoA/ROCK pathway

OBJECTIVE Pulmonary artery hypertension(PAH)is a severe disease characterized by the mean pulmonary artery pressure exceeding 25 mm Hg at rest.PAH could induce right heart failure and has a very high mortality rate.At present,several kinds of drugs have been used in the treatment of PAH.However,most of these drugs aim to relax pulmonary arteries and do not inhibit the injury of vessels.In other words,the drugs available for PAH treatment do not improve the survival rate of PAH patients and cannot satisfy the needs in clinic.To discover and develop novel candidate compounds effective on the treatment of pulmonary artery injury and remodeling will be very important.Based on these background,the present study aimed to study the protective effect of two novel Rho-kinases(Rho-associated coiledcoil forming protein serine/threonine kinase,ROCK)inhibitors,DL0805 derivatives(DL0805-1and DL0805-2),on pulmonary arterial cells and further evaluate the underlying mechanisms and the possibility of DL0805 derivatives become therapeutic drugs for PAH.METHODS The primary cultured pulmonary arterial cells including human pulmonary artery endothelium cells(HPAECs)and human pulmonary artery smooth muscle cells(HPASMCs)were used in this study.HPAECs were injured under hypoxia environment(1%O2)and treated with or without DL0805 derivatives.After 48 h,the proliferation and oxidative stress were observed.CCK8 was used to detect cell viability.DCFH-DA was used as probe for reactive oxygen species(ROS)under fluorescence imaging system.HPASMCs was stimulated by growth factors including platelet-derived growth factor-BB(PDGF-BB)and Fetal Bovine Serum(FBS).The proliferation was observed in the cells treated with or without DL0805 derivatives.HPASMCs treated with or without DL0805 derivatives were further incubated with endothelin(ET-1),the proliferation and cytoskeleton remodeling of cells were detected by immunofluorescence assay.At last,Western blotting(WB)and immunofluorescence assay were employed to analysis the underlying mechanisms in the above experiments.RESULTS 10μmol·L-1DL0805-2 could inhibit the proliferation of HPAECs induced by hypoxia.Each concentration of DL0805-1 and DL0805-2attenuated the production of ROS in HPAECs.Results from WB indicated that DL0805 derivatives decreased the injury of HPAECs induced by hypoxia through the inhibition of the expression of Rho A and the activity of ROCK.On HPASMCs,DL0805 derivatives reduced the proliferation induced by PDGF-BB and FBS and inhibited cytoskeleton remodeling induced by ET-1.Immunofluorescence assay showed that DL0805 derivatives inhibited ROCK activity and down regulated the phosphorylation levels of ROCK substrates.CONCLUSION DL0805derivatives exhibited protective effect on pulmonary arterial cells including endothelium cells and smooth muscle cells.Among the above experiments,DL0805-2 showed stronger potency than DL0805-1.These two compounds might protect the cells through the inhibition of Rho A/ROCK pathway and they probably have the potential in the treatment of PAH and deserve further evaluation.

GRK2-YAP signaling is implicated in pulmonary arterial hypertension development

Background:Pulmonary arterial hypertension(PAH)is characterized by excessive proliferation of small pulmonary arterial vascular smooth muscle cells(PASMCs),endothelial dysfunction,and extracellular matrix remodeling.G protein-coupled receptor kinase 2(GRK2)plays an important role in the maintenance of vascular tone and blood flow.However,the role of GRK2 in the pathogenesis of PAH is unknown.Methods:GRK2 levels were detected in lung tissues from healthy people and PAH patients.C57BL/6 mice,vascular smooth muscle cell-specific Grk2-knockout mice(Grk2^(∆SM22)),and littermate controls(Grk2^(flox/flox))were grouped into control and hypoxia mice(n=8).Pulmonary hypertension(PH)was induced by exposure to chronic hypoxia(10%)combined with injection of the SU5416(cHx/SU).The expression levels of GRK2 and Yes-associated protein(YAP)in pulmonary arteries and PASMCs were detected by Western blotting and immunofluorescence staining.The mRNA expression levels of Grk2 and Yes-associated protein(YAP)in PASMCs were quantified with real-time polymerase chain reaction(RT-PCR).Wound-healing assay,3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide(MTT)assay,and 5-Ethynyl-2′-deoxyuridine(EdU)staining were performed to evaluate the proliferation and migration of PASMCs.Meanwhile,the interaction among proteins was detected by immunoprecipitation assays.Results:The expression levels of GRK2 were upregulated in the pulmonary arteries of patients with PAH and the lungs of PH mice.Moreover,cHx/SU-induced PH was attenuated in Grk2^(∆SM22) mice compared with littermate controls.The amelioration of PH in Grk2^(∆SM22) mice was accompanied by reduced pulmonary vascular remodeling.In vitro study further confirmed that GRK2 knock-down significantly altered hypoxia-induced PASMCs proliferation and migration,whereas this effect was severely intensified by overexpression of GRK2.We also identified that GRK2 promoted YAP expression and nuclear translocation in PASMCs,resulting in excessive PASMCs proliferation and migration.Furthermore,GRK2 is stabilized by inhibiting phosphorylating GRK2 on Tyr86 and subsequently activating ubiquitylation under hypoxic conditions.Conclusion:Our findings suggest that GRK2 plays a critical role in the pathogenesis of PAH,via regulating YAP expression and nuclear translocation.Therefore,GRK2 serves as a novel therapeutic target for PAH treatment.