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.

Prevalence of Anti-endothelial Cell Antibodies in Patients with Pulmonary Arterial Hypertension Associated with Connective Tissue Diseases

Objective To investigate the prevalence of anti-endothelial cell antibodies (AECAs) in the sera of connective tissue diseases (CTD) patients with pulmonary arterial hypertension (PAH) and its correlation with clinical manifestations. Methods AECAs in sera of 39 CTD patients with PAH,22 CTD patients without PAH,and 10 healthy donors as controls were detected with Western blotting. The prevalence of different AECAs in different groups was compared and its correlation with clinical manifestations was also investigated. Results The prevalence of AECAs was 82.1% in CTD patients with PAH,72.7% in CTD patients without PAH,and 20.0% in healthy donors. Anti-22 kD AECA was only detected in CTD patients with PAH (15.4%). Anti-75 kD AECA was more frequently detected in CTD patients with PAH than in those without PAH (51.3% vs. 22.7%,P<0.05). In CTD patients with PAH,anti-75 kD AECA was more frequently detected in those with Raynaud’s phenomenon or with positive anti-RNP antibody. Conclusion AECAs could be frequently detected in CTD patients with or without PAH,while anti-22 kD and anti-75 kD AECA might be specific in CTD patients with PAH.

Proteomic analysis of the serum in patients with idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension(IPAH) is a rare disease of unknown etiology.The exact pathogenesis of pulmonary arterial hypertension is still not well known.In the past decades,many protein molecules have been found to be in-volved in the development of IPAH.With proteomic techniques,profiling of human plasma proteome becomes more feasible in searching for disease-related markers.In present study,we showed the protein expression profiles of the serum of IPAH and healthy controls after depleting a few high-abundant proteins in serum.Thirteen spots had changed significantly in IPAH com-pared with healthy controls and were identified by LC-MS/MS.Alpha-1-antitrypsin and vitronectin were down-regulated in IPAH and may be valuable candidates for further explorations of their roles in the development of IPAH.

Home-made fenestrated amplatzer occluder for atrial septal defect and pulmonary arterial hypertension

We report the management of a patient with secundum atrial septal defect （ASD） and severe pulmonary hypertension. A 65-year-old male with recently diagnosed atrial septal defect was referred to our centre for decompensated right heart failure with rest and exercise induced dispnea and severe pulmonary hypertension. Right heart catheterization confirmed a mean pulmonary pressure of about 55 mmHg and a Qp/Qs of 2.7. An occlusion test with a compliant large balloon demonstrated partial fall of pulmonary arterial pressure. The implantation of a home-made fenestrated Amplatzer ASD Occluder （ASO） was planned in order to decrease left-to-right shunt and promote further decrease of pulmonary arterial pressure in the long-term. Thus, by means of mechanical intracardiac echocardiography study with a 9F 9 MHz Ultralce catheter （Boston Scientific Corp.）, we selected a 34 mm ASO for implantation. Four millimeter fenestration was made inflating a 4 mm non-compliant coronary balloon throughout the waist of the ASO, which was successfully implanted under intmcardiac echocardiography. After six months, a decrease of pulmonary arterial pressure to 24 mmHg and full compensated right heart failure was observed on transthoracic echocardiography and clinical examination. This case suggests that Wanscatheter closure with home-made fenestrated ASD in elderly patients with severe pulmonary hypertension is feasible.

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.

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.

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.

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.

Novel therapy for idiopathic pulmonary arterial hypertension： Can hepatocyte growth factor be beneficial？

Idiopathic pulmonary arterial hypertension （IPAH） is a progressive, nearly fatal condition that until recently has had very few treatment options. Median survival time for untreated IPAH was 2.8 years without effective drug intervention. IPAH is characterized by deregulated proliferation of pulmonary arterial endothelial and intimal smooth muscle cells resulting in progressive pulmonary vascular remodeling and an increase in pulmonary arterial pressure. In order to alleviate their symptoms, anticoagulants, diuretics, calcium channel blockers and inotropic agents have been used to treat patients with PAH. Moreover, specific targeted therapies using prostacyclins,

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.

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.

Pulmonary arterial hypertension related to human immunodeficiency virus infection:A case series

AIM: To present 18 new cases of human immunodeficiency virus(HIV)-related pulmonary arterial hypertension(PAH) with presenting features,treatment options and follow-up data.METHODS: This is a single-centre,retrospective,observational study that used prospectively collected data,conducted during a 14-year period on HIV-related PAH patients who were referred to a pulmonary hy-pertension unit. All patients infected with HIV were consecutively admitted for an initial evaluation of PAH during the study period and included in our study. Right heart catheterisation was used for the diagnosis of PAH. Specific PAH treatment was started according to the physician's judgment and the recommendations for idiopathic PAH. The data collected included demographic characteristics,parameters related to both HIV infection and PAH and disease follow-up.RESULTS: Eighteen patients were included. Intravenous drug use was the major risk factor for HIV infection. Risk factors for PAH,other than HIV infection,were present in 55.5% patients. The elapsed time between HIV infection and PAH diagnoses was 12.2 ± 6.9 years. At PAH diagnosis,94.1% patients had a CD4 cell count > 200 cells/μL. Highly active antiretroviral therapy(present in 47.1% patients) was associated with an accelerated onset of PAH. Survival rates were 93.8%,92.9% and 85.7% at one,two and three years,respectively. Concerning specific therapy,33.3% of the patients were started on a prostacyclin analogue,and the rest were on oral drugs,mainly phosphodiesterase-5 inhibitors. During the follow-up period,specific therapy was de-escalated to oral drugs in all of the living patients.CONCLUSION: The survival rates of HIV-related PAH patients were higher,most likely due to new aggressive specific therapy. The majority of patients were on oral specific therapy and clinically stable. Moreover,sildenafil appears to be a safe therapy for less severe HIVrelated 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 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.

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.