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2.
ESC Heart Fail ; 11(3): 1540-1552, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38224960

RESUMO

AIMS: In pulmonary arterial hypertension (PAH), upfront combination therapy with ERA and PDE5i is associated with a reduction in morbidity and mortality events and improves standard haemodynamics, but data remain limited. Aims of this study were (i) to capture detailed haemodynamic effects of rapid sequential dual combination therapy in patients with newly diagnosed PAH; (ii) to monitor the impact of treatment initiation on clinical variables and patients' risk status, and (iii) to compare the treatment effect in patients with 'classical PAH' and 'PAH with co-morbidities'. METHODS: Fifty patients (median age 57 [42-71] years, 66% female) with newly diagnosed PAH (76% idiopathic) were treated with a PD5i/sGC-S or ERA, followed by addition of the respective other drug class within 4 weeks. All patients underwent repeat right heart catheterization (RHC) during early follow-up. RESULTS: At early repeat RHC (7 ± 2 months), there were substantial reductions in mean pulmonary artery pressure (mPAP: 52.2 ± 13.5 to 39.0 ± 10.6 mmHg; -25.3%), and pulmonary vascular resistance (PVR: 12.1 ± 5.7 to 5.8 ± 3.1 WU; -52.1%), and an increase in cardiac index (2.1 ± 0.4 to 2.7 ± 0.7 mL/min/m2; +32.2%) (all P < 0.05). Haemodynamic improvements correlated with improved clinical parameters including 6-min walking distance (336 ± 315 to 389 ± 120 m), NTproBNP levels (1.712 ± 2.024 to 506 ± 550 ng/L, both P < 0.05) and WHO-FC at 12 months, resulting in improved risk status, and were found in patients with few (n = 37) or multiple cardiovascular co-morbidities (BMI > 30 kg/m2, hypertension, diabetes, coronary artery disease [≥3]; n = 13), albeit baseline PVR in PAH patients with multiple co-morbidities was lower (9.3 ± 4.4 vs. 13.1 ± 5.9 WU) and PVR reduction less pronounced compared with those with few co-morbidities (-42.7% vs. -54.7%). However, comprehensive haemodynamic assessment considering further variables of prognostic relevance such as stroke volume index and pulmonary artery compliance showed similar improvements among the two groups (SVI: +50.0% vs. +49.2%; PAC: 91.7% vs. 100.0%). Finally, the 4-strata risk assessment approach was better able to capture treatment response as compared with other approaches, particularly in patients with co-morbidities. CONCLUSIONS: Rapid sequential combination therapy with PDE5i/sGC-S and ERA substantially ameliorates cardiopulmonary haemodynamics at early follow-up in patients without, and to a lesser extent, with cardiovascular co-morbidities. This occurs in line with improvements of clinical parameters and risk status.


Assuntos
Quimioterapia Combinada , Hemodinâmica , Inibidores da Fosfodiesterase 5 , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Hemodinâmica/fisiologia , Hemodinâmica/efeitos dos fármacos , Idoso , Adulto , Inibidores da Fosfodiesterase 5/administração & dosagem , Inibidores da Fosfodiesterase 5/uso terapêutico , Hipertensão Arterial Pulmonar/tratamento farmacológico , Hipertensão Arterial Pulmonar/fisiopatologia , Hipertensão Arterial Pulmonar/diagnóstico , Seguimentos , Resultado do Tratamento , Cateterismo Cardíaco/métodos , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/uso terapêutico , Resistência Vascular , Fatores de Tempo , Antagonistas dos Receptores de Endotelina/administração & dosagem
3.
Sci Rep ; 13(1): 17452, 2023 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-37838799

RESUMO

The safety of prolonged high-altitude stays and exercise for physically fit post-myocardial infarction (MI) patients is unclear. Myocardial tissue hypoxia and pulmonary hypertension can affect cardiac function and electrophysiology, possibly contributing to arrhythmias. We included four non-professional male athletes, clinically stable after left ventricular MI (three with ST-segment elevation MI and one with non-ST-segment elevation MI) treated with drug-eluting stents for single-vessel coronary artery disease. Oxygen levels were reduced to a minimum of 11.8%, then restored to 20.9%. We conducted electrocardiography (ECG), ergometry, and echocardiography assessments in normoxic and hypoxic conditions. With an average age of 57.8 ± 3.3 years and MI history 37 to 104 months prior, participants experienced a significant increase in QTc intervals during hypoxia using Bazett's (from 402 ± 13 to 417 ± 25 ms), Fridericia's (from 409 ± 12 to 419 ± 19 ms), and Holzmann's formulas (from 103 ± 4 to 107 ± 6%) compared to normoxia. This effect partially reversed during recovery. Echocardiographic signs of pulmonary hypertension during normobaric hypoxia correlated significantly with altered QTc intervals (p < 0.001). Despite good health and complete revascularization following MI, susceptibility to hypoxia-induced QTc prolongation and ventricular ectopic beats persists, especially during physical activity. MI survivors planning high-altitude activities should consult cardiovascular specialists with high-altitude medicine expertise.


Assuntos
Hipertensão Pulmonar , Infarto do Miocárdio , Infarto do Miocárdio sem Supradesnível do Segmento ST , Complexos Ventriculares Prematuros , Humanos , Masculino , Pessoa de Meia-Idade , Eletrocardiografia , Hipóxia
6.
Curr Heart Fail Rep ; 19(6): 386-399, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36166185

RESUMO

PURPOSE OF REVIEW: Since CRS is critically dependent on right heart function and involved in interorgan crosstalk, assessment and monitoring of both right heart and kidney function are of utmost importance for clinical outcomes. This systematic review aims to comprehensively report on novel diagnostic and therapeutic paradigms that are gaining importance for the clinical management of the growing heart failure population suffering from CRS. RECENT FINDINGS: Cardiorenal syndrome (CRS) in patients with heart failure is associated with poor outcome. Although systemic venous congestion and elevated central venous pressure have been recognized as main contributors to CRS, they are often neglected in clinical practice. The delicate hemodynamic balance in CRS is particularly determined by the respective status of the right heart. The consideration of hemodynamic and CRS profiles is advantageous in tailoring treatment for better preservation of renal function. Assessment and monitoring of right heart and renal function by known and emerging tools like renal Doppler ultrasonography or new biomarkers may have direct clinical implications.


Assuntos
Síndrome Cardiorrenal , Insuficiência Cardíaca , Humanos , Hemodinâmica , Biomarcadores
7.
J Cachexia Sarcopenia Muscle ; 12(6): 1501-1512, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34498427

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive disease with limited survival. Iron deficiency (ID) correlates with disease severity and mortality. While oral iron supplementation was shown to be insufficient in such patients, the potential impact of parenteral iron on clinical measures warrants further investigation. METHODS: We retrospectively analysed the long-term effects of intravenous ferric carboxymaltose (FCM) on iron status and clinical measures in patients with PAH and ID [ferritin < 100 µg/L or ferritin 100-300 µg/L and transferrin saturation (TSAT) < 20%] who were on stable targeted PAH therapy, compared with matched controls without ID. Patients with ID received a single infusion of FCM (500 to 1000 mg). Clinical measures monitored included exercise capacity, World Health Organization (WHO) functional class, ESC/ERS risk status, and hospitalizations. The observation period was up to 18 months. RESULTS: One hundred and seventeen patients (mean age 60.9 ± 16.1 years; 64.1% females) with confirmed PAH and on stable targeted therapy for ≥3 months were included (58 with and 59 patients without ID who did not receive FCM). In patients with ID, iron supplementation with FCM resulted in an immediate and sustained improvement of iron status for up to 18 months (serum iron, ferritin, TSAT, all P < 0.01). Fourteen patients in the FCM group received a second FCM infusion after 9.6 ± 4.8 months due to recurrent ID. At 6 and 18 months after FCM infusion, 6 min walk distance improved from 377.5 ± 15.9 at baseline to 412.5 ± 15.1 and 400.8 ± 14.5 m, respectively (both P < 0.05). WHO functional class (P < 0.05) and ESC/ERS risk status also improved, and there was a reduction of hospitalizations for worsening PAH in the 12 months post vs. prior to iron repletion (P = 0.029). No significant changes were observed in the control group. FCM was well tolerated in all patients, with no severe adverse events. CONCLUSIONS: In addition to targeted therapy, correction of ID by parenteral iron supplementation with FCM appears feasible and safe, has sustained effects on iron status, and may improve the clinical status and hospitalization rates in patients with PAH. Larger controlled studies are required to confirm this finding.


Assuntos
Anemia Ferropriva , Deficiências de Ferro , Hipertensão Arterial Pulmonar , Adulto , Idoso , Feminino , Compostos Férricos , Humanos , Masculino , Maltose/análogos & derivados , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
Pulm Circ ; 9(2): 2045894019835649, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30767601

RESUMO

Atrial septal defect (ASD) is one of the most frequent congenital heart diseases (CHD). Up to 10% of adults with an ASD develop pulmonary arterial hypertension (PAH, PAH-CHD) in their lifetime. Despite improved therapy options, gravidity remains a substantial risk for both maternal and neonatal mortality in PAH-CHD patients. In our patient, gravidity remained uncomplicated until week 32, under specific monotherapy with tadalafil, before onset of dyspnea and markedly increase of systolic pulmonary arterial pressure (PAP) was observed in echocardiography. Urgent Caesarian delivery was performed without any complications and a healthy baby was born. However, immediately afterwards, the patient desaturated (SpO2 65%, PaO2 37 mmHg) due to a shunt inversion with now right-to-left shunt through the residual ASD. She was admitted to our intensive care unit and specific PH therapy was escalated to a triple combination of tadalafil, ambrisentan, and iloprost. Hereafter, in a slow process of approximately three weeks, the patient's condition improved to baseline. This rare case of a young woman with high-risk pregnancy in PAH-CHD highlights the hemodynamic changes and treatment options during pregnancy in these patients and emphasizes the urgency of a close monitoring at specialized GUCH/PAH centers with experience in managing PAH under these circumstances.

9.
Int J Cardiol ; 283: 152-158, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30777406

RESUMO

OBJECTIVE: Heart failure with preserved ejection fraction (HFpEF) is frequently associated with pulmonary hypertension (PH), which substantially impacts survival. Based on pulmonary vascular resistance (PVR) and the diastolic pressure gradient (DPG), current guidelines distinguish between isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH). However, the therapeutic consequences of this sub-classification remain entirely unclear. We specifically investigated the efficacy and safety of PDE5i in patients with HFpEF and CpcPH. METHODS: In 40 hemodynamically precisely characterized patients with HFpEF and Cpc-PH who were treated with a PDE5i for at least 12 months, the therapeutic effect on 6-minute walk distance (6MWD), WHO functional class (FC), NTproBNP levels, right ventricular function, and hospitalization rates was evaluated. RESULTS: Patients' mean age was 73 ±â€¯9 years, and comorbidities were frequent (78% hypertension, 58% atrial fibrillation, 35% diabetes). Initially, 38 patients (95%) were in WHO-FC III and 2 patients (5%) in WHO-FC II. Prior to PDE5i initiation, mean PAPm was 46.2 ±â€¯10.3 mmHg, PAWP 21.2 ±â€¯4.7 mmHg, DPG 5.5 ±â€¯7.2 mmHg, and PVR 6.2 ±â€¯3.0 WU. After 12 months of PDE5i therapy, the 6MWD increased from initially 277 ±â€¯17 to 340 ±â€¯18 m (p < 0.001), and the proportion of patients in WHO-FC I/II increased from 5% to 37.5%. NTproBNP levels decreased by 33% (p = 0.004), and TAPSE improved from 16.8 ±â€¯0.7 mm at baseline to 18.2 ±â€¯0.6 mm (p = 0.01). The rate of HF-associated hospitalizations was substantially lower in the 12 months post PDE5i initiation compared to the prior 12 months. The DPG had no impact on the response to therapy. No deaths occurred, and typical side effects of PDE5i were observed. CONCLUSION: These data indicate that at least a subset of precisely characterized patients with HFpEF and CpcPH who tolerate PDE5i may benefit from targeted therapy. A randomized study in this particular sub-population is warranted.


Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Hipertensão Pulmonar/tratamento farmacológico , Volume Sistólico/fisiologia , Tadalafila/uso terapêutico , Resistência Vascular/fisiologia , Idoso , Cateterismo Cardíaco , Ecocardiografia , Feminino , Seguimentos , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/fisiopatologia , Masculino , Inibidores da Fosfodiesterase 5/uso terapêutico , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Função Ventricular Direita/fisiologia
10.
Int J Cardiol ; 272S: 53-62, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30527996

RESUMO

In the summer of 2016, delegates from the German Society of Cardiology (DGK), the German Respiratory Society (DGP), and the German Society of Pediatric Cardiology (DGPK) met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary hypertension (PH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines, aiming at their practical implementation, considering country-specific issues, and including new evidence, where available. To this end, a number of working groups was initiated, one of which was specifically dedicated to PH associated with left heart disease. In this context, the European Guidelines point out that the drugs currently approved to treat patients with PAH (prostanoids, endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, sGC stimulators) have not sufficiently been investigated in other forms of PH. However, despite the lack of respective efficacy data, an uncritical use of targeted PAH drugs in patients with PH associated with left heart disease is currently observed at an increasing rate. This development is a matter of concern. On the other hand, PH is a frequent problem that is highly relevant for morbidity and mortality in patients with left heart disease. In that sense, the distinction between isolated post-capillary pulmonary hypertension (IpcPH) and combined post- and pre-capillary pulmonary hypertension (CpcPH) and their proper definition may be of particular relevance. The detailed results and recommendations of the working group on PH associated with left heart disease, which were last updated in the spring of 2018, are summarized in this article.


Assuntos
Conferências de Consenso como Assunto , Insuficiência Cardíaca/terapia , Hipertensão Pulmonar/terapia , Guias de Prática Clínica como Assunto/normas , Disfunção Ventricular Esquerda/terapia , Alemanha/epidemiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/epidemiologia , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/epidemiologia
11.
Eur Respir J ; 50(2)2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28775047

RESUMO

The 2015 European pulmonary hypertension (PH) guidelines propose a risk stratification strategy for patients with pulmonary arterial hypertension (PAH). Low-, intermediate- and high-risk strata are defined by estimated 1-year mortality risks of <5%, 5-10% and >10%, respectively. This risk assessment strategy awaits validation.We analysed data from patients with newly diagnosed PAH enrolled into COMPERA (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension), a European-based PH registry. An abbreviated version of the risk assessment strategy proposed by the European PH guidelines was applied, using the following variables: World Health Organization functional class, 6-min walking distance, brain natriuretic peptide or its N-terminal fragment, right atrial pressure, cardiac index and mixed venous oxygen saturation.Data from 1588 patients were analysed. Mortality rates were significantly different between the three risk strata (p<0.001 for all comparisons). In the entire patient population, the observed mortality rates 1 year after diagnosis were 2.8% in the low-risk cohort (n=196), 9.9% in the intermediate-risk cohort (n=1116) and 21.2% in the high-risk cohort (n=276). In addition, the risk assessment strategy proved valid at follow-up and in major PAH subgroups.An abbreviated version of the risk assessment strategy proposed by the current European PH guidelines provides accurate mortality estimates in patients with PAH.


Assuntos
Hipertensão Pulmonar/mortalidade , Medição de Risco , Adulto , Idoso , Idoso de 80 Anos ou mais , Europa (Continente)/epidemiologia , Feminino , Hemodinâmica , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Guias de Prática Clínica como Assunto , Estudos Prospectivos , Sistema de Registros , Índice de Gravidade de Doença , Teste de Caminhada
12.
Sci Rep ; 7: 44549, 2017 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-28317848

RESUMO

Electrocardiography (ECG) data are multidimensional temporal data with ubiquitous applications in the clinic. Conventionally, these data are presented visually. It is presently unclear to what degree data sonification (auditory display), can enable the detection of clinically relevant cardiac pathologies in ECG data. In this study, we introduce a method for polyphonic sonification of ECG data, whereby different ECG channels are simultaneously represented by sound of different pitch. We retrospectively applied this method to 12 samples from a publicly available ECG database. We and colleagues from our professional environment then analyzed these data in a blinded way. Based on these analyses, we found that the sonification technique can be intuitively understood after a short training session. On average, the correct classification rate for observers trained in cardiology was 78%, compared to 68% and 50% for observers not trained in cardiology or not trained in medicine at all, respectively. These values compare to an expected random guessing performance of 25%. Strikingly, 27% of all observers had a classification accuracy over 90%, indicating that sonification can be very successfully used by talented individuals. These findings can serve as a baseline for potential clinical applications of ECG sonification.


Assuntos
Fibrilação Atrial/diagnóstico por imagem , Eletrocardiografia/métodos , Coração/diagnóstico por imagem , Reconhecimento Fisiológico de Modelo/fisiologia , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Complexos Ventriculares Prematuros/diagnóstico por imagem , Fibrilação Atrial/fisiopatologia , Bases de Dados Factuais , Eletrocardiografia/instrumentação , Coração/fisiopatologia , Humanos , Reconhecimento Visual de Modelos/fisiologia , Estudos Retrospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Som , Complexos Ventriculares Prematuros/fisiopatologia
13.
Heart ; 103(8): 592-598, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28100544

RESUMO

OBJECTIVE: In patients with pulmonary arterial hypertension (PAH), supportive therapies may be beneficial in addition to targeted medical treatment. Here, we evaluated the effectiveness and safety of oscillatory whole-body vibration (WBV) in patients on stable PAH therapy. METHODS: Twenty-two patients with PAH (mean PAP≥25 mm Hg and pulmonary arterial wedge pressure (PAWP)≤15 mm Hg) who were in world health organization (WHO)-Functional Class II or III and on stable PAH therapy for≥3 months, were randomised to receive WBV (16 sessions of 1-hour duration within 4 weeks) or to a control group, that subsequently received WBV. Follow-up measures included the 6-min walking distance (6MWD), cardiopulmonary exercise testing (CPET), echocardiography, muscle-power, and health-related quality of life (HRQoL; SF-36 and LPH questionnaires). RESULTS: When compared to the control group, patients receiving WBV exhibited a significant improvement in the primary endpoint, the 6MWD (+35.4±10.9 vs -4.4±7.6 m), resulting in a net benefit of 39.7±7.8 m (p=0.004). WBV was also associated with substantial improvements in CPET variables, muscle power, and HRQoL. The combined analysis of all patients (n=22) indicated significant net improvements versus baseline in the 6MWD (+38.6 m), peakVO2 (+65.7 mL/min), anaerobic threshold (+40.9 mL VO2/min), muscle power (+4.4%), and HRQoL (SF-36 +9.7, LPH -11.5 points) (all p<0.05). WBV was well tolerated in all patients, and no procedure-related severe adverse events (SAEs) occurred. CONCLUSIONS: WBV substantially improves exercise capacity, physical performance, and HRQoL in patients with PAH who are on stable targeted therapy. This methodology may be utilised in structured training programmes, and may be feasible for continuous long-term physical exercise in these patients. TRIAL REGISTRATION NUMBER: NCT01763112; Results.


Assuntos
Tolerância ao Exercício , Hipertensão Pulmonar/terapia , Artéria Pulmonar/fisiopatologia , Pressão Propulsora Pulmonar , Vibração/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Aptidão Cardiorrespiratória , Ecocardiografia , Feminino , Alemanha , Nível de Saúde , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/psicologia , Masculino , Pessoa de Meia-Idade , Força Muscular , Oscilometria , Projetos Piloto , Estudos Prospectivos , Qualidade de Vida , Recuperação de Função Fisiológica , Inquéritos e Questionários , Fatores de Tempo , Resultado do Tratamento , Teste de Caminhada
14.
Arterioscler Thromb Vasc Biol ; 35(6): 1434-44, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25908763

RESUMO

OBJECTIVE: Neointima formation after vascular injury remains a significant problem in clinical cardiology, and current preventive strategies are suboptimal. Phosphatidylinositol 3'-kinase is a central downstream mediator of growth factor signaling, but the role of phosphatidylinositol 3'-kinase isoforms in vascular remodeling remains elusive. We sought to systematically characterize the precise role of catalytic class IA phosphatidylinositol 3'-kinase isoforms (p110α, p110ß, p110δ), which signal downstream of receptor tyrosine kinases, for vascular remodeling in vivo. APPROACH AND RESULTS: Western blot analyses revealed that all 3 isoforms are abundantly expressed in smooth muscle cells. To analyze their significance for receptor tyrosine kinases-dependent cellular responses, we used targeted gene knockdown and isoform-specific small molecule inhibitors of p110α (PIK-75), p110ß (TGX-221), and p110δ (IC-87114), respectively. We identified p110α to be crucial for receptor tyrosine kinases signaling, thus affecting proliferation, migration, and survival of rat, murine, and human smooth muscle cells, whereas p110ß and p110δ activities were dispensable. Surprisingly, p110δ exerted noncatalytic functions in smooth muscle cell proliferation, but had no effect on migration. Based on these results, we generated a mouse model of smooth muscle cell-specific p110α deficiency (sm-p110α(-/-)). Targeted deletion of p110α in sm-p110α(-/-) mice blunted growth factor-induced cellular responses and abolished neointima formation after balloon injury of the carotid artery in mice. In contrast, p110δ deficiency did not affect vascular remodeling in vivo. CONCLUSIONS: Receptor tyrosine kinases-induced phosphatidylinositol 3'-kinase signaling via the p110α isoform plays a central role for vascular remodeling in vivo. Thus, p110α represents a selective target for the prevention of neointima formation after vascular injury, whereas p110ß and p110δ expression and activity do not play a significant role.


Assuntos
Classe Ia de Fosfatidilinositol 3-Quinase/metabolismo , Remodelação Vascular/fisiologia , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Classe Ia de Fosfatidilinositol 3-Quinase/farmacologia , Humanos , Camundongos , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/enzimologia , Neointima/prevenção & controle , Isoformas de Proteínas , Ratos , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais
15.
Arterioscler Thromb Vasc Biol ; 35(5): 1236-45, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25745058

RESUMO

OBJECTIVE: Despite modern therapies, pulmonary arterial hypertension (PAH) harbors a high mortality. Vascular remodeling is a hallmark of the disease. Recent clinical studies revealed that antiremodeling approaches with tyrosine-kinase inhibitors such as imatinib are effective, but its applicability is limited by significant side effects. Although imatinib has multiple targets, expression analyses support a role for platelet-derived growth factor (PDGF) in the pathobiology of the disease. However, its precise role and downstream signaling events have not been established. APPROACH AND RESULTS: Patients with PAH exhibit enhanced expression and phosphorylation of ß PDGF receptor (ßPDGFR) in remodeled pulmonary arterioles, particularly at the binding sites for phophatidyl-inositol-3-kinase and PLCγ at tyrosine residues 751 and 1021, respectively. These signaling molecules were identified as critical downstream mediators of ßPDGFR-mediated proliferation and migration of pulmonary arterial smooth muscle cells. We, therefore, investigated mice expressing a mutated ßPDGFR that is unable to recruit phophatidyl-inositol-3-kinase and PLCγ (ßPDGFR(F3/F3)). PDGF-dependent Erk1/2 and Akt phosphorylation, cyclin D1 induction, and proliferation, migration, and protection against apoptosis were abolished in ßPDGFR(F3/F3) pulmonary arterial smooth muscle cells. On exposure to chronic hypoxia, vascular remodeling of pulmonary arteries was blunted in ßPDGFR(F3/F3) mice compared with wild-type littermates. These alterations led to protection from hypoxia-induced PAH and right ventricular hypertrophy. CONCLUSIONS: By means of a genetic approach, our data provide definite evidence that the activated ßPDGFR is a key contributor to pulmonary vascular remodeling and PAH. Selective disruption of PDGF-dependent phophatidyl-inositol-3-kinase and PLCγ activity is sufficient to abolish these pathogenic responses in vivo, identifying these signaling events as valuable targets for antiremodeling strategies in PAH.


Assuntos
Hipertensão Pulmonar/genética , Fator de Crescimento Derivado de Plaquetas/genética , Transdução de Sinais/genética , Remodelação Vascular/genética , Animais , Células Cultivadas , Modelos Animais de Doenças , Hipertensão Pulmonar/patologia , Camundongos , Mutação , Fator de Crescimento Derivado de Plaquetas/metabolismo , Sensibilidade e Especificidade , Transdução de Sinais/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
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