RESUMEN
Pulmonary veno-occlusive disease (PVOD) occurs in humans either as a heritable form (hPVOD) due to biallelic inactivating mutations of EIF2AK4 (encoding GCN2) or as a sporadic form in older age (sPVOD). The chemotherapeutic agent mitomycin C (MMC) is a potent inducer of PVOD in humans and in rats (MMC-PVOD). Here, we compared human hPVOD and sPVOD, and MMC-PVOD pathophysiology at the histological, cellular, and molecular levels to unravel common altered pathomechanisms. MMC exposure in rats was associated primarily with arterial and microvessel remodeling, and secondarily by venous remodeling, when PVOD became symptomatic. In all forms of PVOD tested, there was convergent GCN2-dependent but eIF2α-independent pulmonary protein overexpression of HO-1 (heme oxygenase 1) and CHOP (CCAAT-enhancer-binding protein [C/EBP] homologous protein), two downstream effectors of GCN2 signaling and endoplasmic reticulum stress. In human PVOD samples, CHOP immunohistochemical staining mainly labeled endothelial cells in remodeled veins and arteries. Strong HO-1 staining was observed only within capillary hemangiomatosis foci, where intense microvascular proliferation occurs. HO-1 and CHOP stainings were not observed in control and pulmonary arterial hypertension lung tissues, supporting the specificity for CHOP and HO-1 involvement in PVOD pathobiology. In vivo loss of GCN2 (EIF2AK4 mutations carriers and Eif2ak4-/- rats) or in vitro GCN2 inhibition in cultured pulmonary artery endothelial cells using pharmacological and siRNA approaches demonstrated that GCN2 loss of function negatively regulates BMP (bone morphogenetic protein)-dependent SMAD1/5/9 signaling. Exogenous BMP9 was still able to reverse GCN2 inhibition-induced proliferation of pulmonary artery endothelial cells. In conclusion, we identified CHOP and HO-1 inhibition, and BMP9, as potential therapeutic options for PVOD.
Asunto(s)
Enfermedad Veno-Oclusiva Pulmonar/metabolismo , Enfermedad Veno-Oclusiva Pulmonar/patología , Animales , Modelos Animales de Enfermedad , Células Endoteliales/metabolismo , Células Endoteliales/patología , Humanos , Hipertensión Pulmonar/metabolismo , Hipertensión Pulmonar/patología , Pulmón/metabolismo , Pulmón/patología , Mutación/genética , Arteria Pulmonar/metabolismo , Arteria Pulmonar/patología , Ratas , Transducción de Señal/fisiología , Factor de Transcripción CHOP/metabolismoRESUMEN
RATIONALE: Pulmonary hypertension (PH) due to left heart disease (LHD), or group 2 PH, is the most prevalent form of PH worldwide. PH due to LHD is often associated with metabolic syndrome (MetS). In 12% to 13% of cases, patients with PH due to LHD display vascular remodeling of pulmonary arteries (PAs) associated with poor prognosis. Unfortunately, the underlying mechanisms remain unknown; PH-targeted therapies for this group are nonexistent, and the development of a new preclinical model is crucial. Among the numerous pathways dysregulated in MetS, inflammation plays also a critical role in both PH and vascular remodeling. OBJECTIVE: We hypothesized that MetS and inflammation may trigger the development of vascular remodeling in group 2 PH. METHODS AND RESULTS: Using supracoronary aortic banding, we induced diastolic dysfunction in rats. Then we induced MetS by a combination of high-fat diet and olanzapine treatment. We used metformin treatment and anti-IL-6 (interleukin-6) antibodies to inhibit the IL-6 pathway. Compared with sham conditions, only supracoronary aortic banding+MetS rats developed precapillary PH, as measured by both echocardiography and right/left heart catheterization. PH in supracoronary aortic banding+MetS was associated with macrophage accumulation and increased IL-6 production in lung. PH was also associated with STAT3 (signal transducer and activator of transcription 3) activation and increased proliferation of PA smooth muscle cells, which contributes to remodeling of distal PA. We reported macrophage accumulation, increased IL-6 levels, and STAT3 activation in the lung of group 2 PH patients. In vitro, IL-6 activates STAT3 and induces human PA smooth muscle cell proliferation. Metformin treatment decreased inflammation, IL-6 levels, STAT3 activation, and human PA smooth muscle cell proliferation. In vivo, in the supracoronary aortic banding+MetS animals, reducing IL-6, either by anti-IL-6 antibody or metformin treatment, reversed pulmonary vascular remodeling and improve PH due to LHD. CONCLUSIONS: We developed a new preclinical model of group 2 PH by combining MetS with LHD. We showed that MetS exacerbates group 2 PH. We provided evidence for the importance of the IL-6-STAT3 pathway in our experimental model of group 2 PH and human patients.
Asunto(s)
Modelos Animales de Enfermedad , Hipertensión Pulmonar/patología , Síndrome Metabólico/complicaciones , Disfunción Ventricular/complicaciones , Animales , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Humanos , Hipertensión Pulmonar/complicaciones , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Macrófagos/metabolismo , Masculino , Síndrome Metabólico/etiología , Olanzapina/toxicidad , Arteria Pulmonar/metabolismo , Arteria Pulmonar/patología , Ratas , Ratas Wistar , Remodelación VascularRESUMEN
The bromodomain and extra-terminal domain family inhibitors (BETi) are a promising new class of anticancer agents. Since numerous anticancer drugs have been correlated to cardiomyopathy, and since BETi can affect non-cancerous tissues, we aimed to investigate in healthy animals any ultrastructural BETi-induced alterations of the heart as compared to skeletal muscle. Male Wistar rats were either treated during 3 weeks with I-BET-151 (2 or 10 mg/kg/day) (W3) or treated for 3 weeks then allowed to recover for another 3 weeks (W6) (3-weeks drug washout). Male C57Bl/6J mice were only treated during 5 days (50 mg/kg/day). We demonstrated the occurrence of ultrastructural alterations and progressive destruction of cardiomyocyte mitochondria after I-BET-151 exposure. Those mitochondrial alterations were cardiac muscle-specific, since the skeletal muscles of exposed animals were similar in ultrastructure presentation to the non-exposed animals. I-BET-151 decreased the respiration rate of heart mitochondria in a dose-dependent manner. At the higher dose, it also decreased mitochondrial mass, as evidenced by reduced right ventricular citrate synthase content. I-BET-151 reduced the right and left ventricular fractional shortening. The concomitant decrease in the velocity-time-integral in both the aorta and the pulmonary artery is also suggestive of an impaired heart function. The possible context-dependent cardiac side effects of these drugs have to be appreciated. Future studies should focus on the basic mechanisms of potential cardiovascular toxicities induced by BETi and strategies to minimize these unexpected complications.
Asunto(s)
Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/ultraestructura , Animales , Electrocardiografía , Corazón/efectos de los fármacos , Corazón/fisiopatología , Masculino , Ratones Endogámicos C57BL , Mitocondrias Cardíacas/efectos de los fármacos , Especificidad de Órganos , Ratas WistarAsunto(s)
Calcinosis/diagnóstico , Calcinosis/etiología , Hipertensión Pulmonar Primaria Familiar/complicaciones , Hipertensión Pulmonar Primaria Familiar/fisiopatología , Hipertensión Arterial Pulmonar/complicaciones , Hipertensión Arterial Pulmonar/fisiopatología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Excessive proliferation and apoptosis resistance in pulmonary vascular cells underlie vascular remodeling in pulmonary arterial hypertension (PAH). Specific treatments for PAH exist, mostly targeting endothelial dysfunction, but high pulmonary arterial pressure still causes heart failure and death. Pulmonary vascular remodeling may be driven by metabolic reprogramming of vascular cells to increase glutaminolysis and glutamate production. The N-methyl-d-aspartate receptor (NMDAR), a major neuronal glutamate receptor, is also expressed on vascular cells, but its role in PAH is unknown. METHODS: We assessed the status of the glutamate-NMDAR axis in the pulmonary arteries of patients with PAH and controls through mass spectrometry imaging, Western blotting, and immunohistochemistry. We measured the glutamate release from cultured pulmonary vascular cells using enzymatic assays and analyzed NMDAR regulation/phosphorylation through Western blot experiments. The effect of NMDAR blockade on human pulmonary arterial smooth muscle cell proliferation was determined using a BrdU incorporation assay. We assessed the role of NMDARs in vascular remodeling associated to pulmonary hypertension, in both smooth muscle-specific NMDAR knockout mice exposed to chronic hypoxia and the monocrotaline rat model of pulmonary hypertension using NMDAR blockers. RESULTS: We report glutamate accumulation, upregulation of the NMDAR, and NMDAR engagement reflected by increases in GluN1-subunit phosphorylation in the pulmonary arteries of human patients with PAH. Kv channel inhibition and type A-selective endothelin receptor activation amplified calcium-dependent glutamate release from human pulmonary arterial smooth muscle cell, and type A-selective endothelin receptor and platelet-derived growth factor receptor activation led to NMDAR engagement, highlighting crosstalk between the glutamate-NMDAR axis and major PAH-associated pathways. The platelet-derived growth factor-BB-induced proliferation of human pulmonary arterial smooth muscle cells involved NMDAR activation and phosphorylated GluN1 subunit localization to cell-cell contacts, consistent with glutamatergic communication between proliferating human pulmonary arterial smooth muscle cells via NMDARs. Smooth-muscle NMDAR deficiency in mice attenuated the vascular remodeling triggered by chronic hypoxia, highlighting the role of vascular NMDARs in pulmonary hypertension. Pharmacological NMDAR blockade in the monocrotaline rat model of pulmonary hypertension had beneficial effects on cardiac and vascular remodeling, decreasing endothelial dysfunction, cell proliferation, and apoptosis resistance while disrupting the glutamate-NMDAR pathway in pulmonary arteries. CONCLUSIONS: These results reveal a dysregulation of the glutamate-NMDAR axis in the pulmonary arteries of patients with PAH and identify vascular NMDARs as targets for antiremodeling treatments in PAH.
Asunto(s)
Ácido Glutámico/metabolismo , Hipertensión Pulmonar/patología , Receptores de N-Metil-D-Aspartato/metabolismo , Remodelación Vascular , Animales , Apoptosis/efectos de los fármacos , Calcio/farmacología , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Maleato de Dizocilpina/farmacología , Endotelina-1/farmacología , Humanos , Hipertensión Pulmonar/metabolismo , Pulmón/metabolismo , Pulmón/patología , Ratones , Ratones Noqueados , Músculo Liso Vascular/citología , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Canales de Potasio con Entrada de Voltaje/metabolismo , Ratas , Receptores de Endotelina/química , Receptores de Endotelina/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/genética , Transducción de Señal/efectos de los fármacos , Remodelación Vascular/efectos de los fármacosRESUMEN
OBJECTIVE: Energy metabolism shift from oxidative phosphorylation toward glycolysis in pulmonary artery smooth muscle cells (PASMCs) is suggested to be involved in their hyperproliferation in pulmonary arterial hypertension (PAH). Here, we studied the role of the deacetylase sirtuin1 (SIRT1) in energy metabolism regulation in PASMCs via various pathways including activation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), master regulator of mitochondrial biogenesis. APPROACH AND RESULTS: Contents of PGC-1α and its downstream targets as well as markers of mitochondrial mass (voltage-dependent anion channel and citrate synthase) were diminished in human PAH PASMCs. These cells and platelet-derived growth factor-stimulated rat PASMCs demonstrated a shift in cellular acetylated/deacetylated state, as evidenced by the increase of the acetylated forms of SIRT1 targets: histone H1 and Forkhead box protein O1. Rat and human PASMC proliferation was potentiated by SIRT1 pharmacological inhibition or specific downregulation via short-interfering RNA. Moreover, after chronic hypoxia exposure, SIRT1 inducible knock out mice displayed a more intense vascular remodeling compared with their control littermates, which was associated with an increase in right ventricle pressure and hypertrophy. SIRT1 activator Stac-3 decreased the acetylation of histone H1 and Forkhead box protein O1 and strongly inhibited rat and human PASMC proliferation without affecting cell mortality. This effect was associated with the activation of mitochondrial biogenesis evidenced by higher expression of mitochondrial markers and downstream targets of PGC-1α. CONCLUSION: Altered acetylation/deacetylation balance as the result of SIRT1 inactivation is involved in the pathogenesis of PAH, and this enzyme could be a promising therapeutic target for PAH treatment.
Asunto(s)
Proliferación Celular , Metabolismo Energético , Miocitos del Músculo Liso/fisiología , Arteria Pulmonar/citología , Sirtuina 1/metabolismo , Acetilación/efectos de los fármacos , Proteínas Adaptadoras Transductoras de Señales/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Citrato (si)-Sintasa/metabolismo , Femenino , Proteína Forkhead Box O1 , Histonas/metabolismo , Humanos , Hipertensión Pulmonar/metabolismo , Hipoxia/metabolismo , Masculino , Ratones Noqueados , Mitocondrias/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Ratas , Sirtuina 1/antagonistas & inhibidores , Sirtuina 1/genética , Remodelación Vascular , Canales Aniónicos Dependientes del Voltaje/metabolismoRESUMEN
Pulmonary arterial hypertension (PAH) is a progressive vascular remodeling disease characterized by a persistent elevation of pulmonary artery pressure, leading to right heart failure and premature death. Exaggerated proliferation and resistance to apoptosis of pulmonary artery smooth muscle cells (PASMCs) is a key component of vascular remodeling. Despite major advances in the field, current therapies for PAH remain poorly effective in reversing the disease or significantly improving long-term survival. Because the transcription factor FOXM1 is necessary for PASMC proliferation during lung morphogenesis and its overexpression stimulates proliferation and evasion of apoptosis in cancer cells, we thus hypothesized that upregulation of FOXM1 in PAH-PASMCs promotes cell expansion and vascular remodeling. Our results showed that FOXM1 was markedly increased in distal pulmonary arteries and isolated PASMCs from PAH patients compared to controls as well as in two preclinical models. In vitro, we showed that miR-204 expression regulates FOXM1 levels and that inhibition of FOXM1 reduced cell proliferation and resistance to apoptosis through diminished DNA repair mechanisms and decreased expression of the pro-remodeling factor survivin. Accordingly, inhibition of FOXM1 with thiostrepton significantly improved established PAH in two rat models. Thus, we show for the first time that FOXM1 is implicated in PAH development and represents a new promising target. KEY MESSAGES: FOXM1 is overexpressed in human PAH-PASMCs and PAH animal models. FOXM1 promotes PAH-PASMC proliferation and resistance to apoptosis. Pharmacological inhibition of FOXM1 improves established PAH in the MCT and Su/Hx rat models. FOXM1 may be a novel therapeutic target in PAH.
Asunto(s)
Proteína Forkhead Box M1/fisiología , Hipertensión Pulmonar/metabolismo , Miocitos del Músculo Liso/fisiología , Arteria Pulmonar/fisiología , Animales , Línea Celular , Proliferación Celular , Proteína Forkhead Box M1/antagonistas & inhibidores , Humanos , Hipertensión Pulmonar/tratamiento farmacológico , Hipertrofia Ventricular Derecha/metabolismo , Masculino , MicroARNs/metabolismo , Arteria Pulmonar/citología , Ratas Sprague-Dawley , Tioestreptona/uso terapéutico , Remodelación VascularRESUMEN
Endothelial dysfunction is a major player in the development and progression of vascular pathology in pulmonary arterial hypertension (PAH), a disease associated with small vessel loss and obstructive vasculopathy that leads to increased pulmonary vascular resistance, subsequent right heart failure, and premature death. Over the past ten years, there has been tremendous progress in our understanding of pulmonary endothelial biology as it pertains to the genetic and molecular mechanisms that orchestrate the endothelial response to direct or indirect injury, and how their dysregulation can contribute to the pathogenesis of PAH. As one of the major topics included in the 2017 Grover Conference Series, discussion centered on recent developments in four areas of pulmonary endothelial biology: (1) angiogenesis; (2) endothelial-mesenchymal transition (EndMT); (3) epigenetics; and (4) biology of voltage-gated ion channels. The present review will summarize the content of these discussions and provide a perspective on the most promising aspects of endothelial dysfunction that may be amenable for therapeutic development.
Asunto(s)
Receptores de Proteínas Morfogenéticas Óseas de Tipo II/inmunología , Hipertensión Pulmonar/inmunología , Intestinos/inmunología , Lipopolisacáridos/toxicidad , Pulmón/inmunología , Receptor Toll-Like 4/inmunología , Animales , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , Humanos , Hipertensión Pulmonar/microbiología , Hipertensión Pulmonar/patología , Intestinos/microbiología , Intestinos/patología , Pulmón/microbiología , Pulmón/patología , Ratones , Ratones Mutantes , Receptor Toll-Like 4/genéticaRESUMEN
[This corrects the article DOI: 10.1155/2015/326385.].
RESUMEN
Pulmonary hypertension (PH) is defined by a mean pulmonary arterial pressure over 25 mmHg at rest and is diagnosed by right heart catheterization. Among the different groups of PH, pulmonary arterial hypertension (PAH) is characterized by a progressive obstruction of distal pulmonary arteries, related to endothelial cell dysfunction and vascular cell proliferation, which leads to an increased pulmonary vascular resistance, right ventricular hypertrophy, and right heart failure. Although the primary trigger of PAH remains unknown, oxidative stress and inflammation have been shown to play a key role in the development and progression of vascular remodeling. These factors are known to increase DNA damage that might favor the emergence of the proliferative and apoptosis-resistant phenotype observed in PAH vascular cells. High levels of DNA damage were reported to occur in PAH lungs and remodeled arteries as well as in animal models of PH. Moreover, recent studies have demonstrated that impaired DNA-response mechanisms may lead to an increased mutagen sensitivity in PAH patients. Finally, PAH was linked with decreased breast cancer 1 protein (BRCA1) and DNA topoisomerase 2-binding protein 1 (TopBP1) expression, both involved in maintaining genome integrity. This review aims to provide an overview of recent evidence of DNA damage and DNA repair deficiency and their implication in PAH pathogenesis.
Asunto(s)
Daño del ADN , Hipertensión Pulmonar/metabolismo , Animales , Reparación del ADN , Genes Mitocondriales , Humanos , Hipertensión Pulmonar/genética , Hipertensión Pulmonar/patología , Estrés OxidativoRESUMEN
BACKGROUND: Mutations in the KCNK3 gene have been identified in some patients suffering from heritable pulmonary arterial hypertension (PAH). KCNK3 encodes an outward rectifier K(+) channel, and each identified mutation leads to a loss of function. However, the pathophysiological role of potassium channel subfamily K member 3 (KCNK3) in PAH is unclear. We hypothesized that loss of function of KCNK3 is a hallmark of idiopathic and heritable PAH and contributes to dysfunction of pulmonary artery smooth muscle cells and pulmonary artery endothelial cells, leading to pulmonary artery remodeling: consequently, restoring KCNK3 function could alleviate experimental pulmonary hypertension (PH). METHODS AND RESULTS: We demonstrated that KCNK3 expression and function were reduced in human PAH and in monocrotaline-induced PH in rats. Using a patch-clamp technique in freshly isolated (not cultured) pulmonary artery smooth muscle cells and pulmonary artery endothelial cells, we found that KCNK3 current decreased progressively during the development of monocrotaline-induced PH and correlated with plasma-membrane depolarization. We demonstrated that KCNK3 modulated pulmonary arterial tone. Long-term inhibition of KCNK3 in rats induced distal neomuscularization and early hemodynamic signs of PH, which were related to exaggerated proliferation of pulmonary artery endothelial cells, pulmonary artery smooth muscle cell, adventitial fibroblasts, and pulmonary and systemic inflammation. Lastly, in vivo pharmacological activation of KCNK3 significantly reversed monocrotaline-induced PH in rats. CONCLUSIONS: In PAH and experimental PH, KCNK3 expression and activity are strongly reduced in pulmonary artery smooth muscle cells and endothelial cells. KCNK3 inhibition promoted increased proliferation, vasoconstriction, and inflammation. In vivo pharmacological activation of KCNK3 alleviated monocrotaline-induced PH, thus demonstrating that loss of KCNK3 is a key event in PAH pathogenesis and thus could be therapeutically targeted.
Asunto(s)
Hipertensión Pulmonar/fisiopatología , Proteínas del Tejido Nervioso/fisiología , Canales de Potasio de Dominio Poro en Tándem/fisiología , Adventicia/patología , Animales , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , División Celular , Endotelio Vascular/patología , Fibroblastos/patología , Predisposición Genética a la Enfermedad , Hemodinámica , Humanos , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/complicaciones , Hipertensión Pulmonar/genética , Hipertrofia Ventricular Derecha/etiología , Inflamación , Masculino , Potenciales de la Membrana , Monocrotalina/toxicidad , Mutación , Miocitos del Músculo Liso/patología , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/genética , Técnicas de Placa-Clamp , Canales de Potasio de Dominio Poro en Tándem/antagonistas & inhibidores , Canales de Potasio de Dominio Poro en Tándem/biosíntesis , Canales de Potasio de Dominio Poro en Tándem/genética , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Sulfonamidas/farmacología , Resistencia Vascular , ortoaminobenzoatos/farmacologíaRESUMEN
PURPOSE OF REVIEW: Pulmonary arterial hypertension (PAH) is a rare disease with poor prognosis and no therapeutics. PAH is characterized by severe remodeling of precapillary pulmonary arteries, leading to increased vascular resistance, pulmonary hypertension compensatory right ventricular hypertrophy, then heart failure and death. PAH pathogenesis shares similarities with carcinogenesis such as excessive cell proliferation, apoptosis resistance, metabolic shifts, or phenotypic transition. Although PAH is not a cancer, comparison of analogous mechanisms between PAH and cancer led to the concept of a cancer-like disease to emerge. MicroRNAs (miRNAs) are small noncoding RNAs involved in the regulation of posttranscriptional gene expression. miRNA dysregulations have been reported as promoter of the development of various diseases including cancers. RECENT FINDINGS: Recent studies revealed that miRNA dysregulations also occur in PAH pathogenesis. In PAH, different miRNAs have been implicated to be the main features of PAH pathophysiology (in pulmonary inflammation, vascular remodeling, angiogenesis, and right heart hypertrophy). SUMMARY: The review summarizes the implication of miRNA dysregulation in PAH development and discusses the similarities and differences with those observed in cancers.
Asunto(s)
Hipertensión Pulmonar/genética , MicroARNs/genética , Neoplasias/genética , Redes Reguladoras de Genes , Humanos , Hipertensión Pulmonar/fisiopatología , MicroARNs/metabolismoRESUMEN
BACKGROUND: Pulmonary veno-occlusive disease (PVOD) is an uncommon form of pulmonary hypertension characterized by the obstruction of small pulmonary veins and a dismal prognosis. PVOD may be sporadic or heritable because of biallelic mutations of the EIF2AK4 gene coding for GCN2. Isolated case reports suggest that chemotherapy may be a risk factor for PVOD. METHODS AND RESULTS: We reported on the clinical, functional, and hemodynamic characteristics and outcomes of 7 cases of PVOD induced by mitomycin-C (MMC) therapy from the French Pulmonary Hypertension Registry. All patients displayed squamous anal cancer and were treated with MMC alone or MMC plus 5-fluoruracil. The estimated annual incidence of PVOD in the French population that have anal cancer is 3.9 of 1000 patients, which is much higher than the incidence of PVOD in the general population (0.5/million per year). In rats, intraperitoneal administration of MMC induced PVOD, as demonstrated by pulmonary hypertension at right-heart catheterization at days 21 to 35 and major remodeling of small pulmonary veins associated with foci of intense microvascular endothelial-cell proliferation of the capillary bed. In rats, MMC administration was associated with dose-dependent depletion of pulmonary GCN2 content and decreased smad1/5/8 signaling. Amifostine prevented the development of MMC-induced PVOD in rats. CONCLUSIONS: MMC therapy is a potent inducer of PVOD in humans and rats. Amifostine prevents MMC-induced PVOD in rats and should be tested as a preventive therapy for MMC-induced PVOD in humans. MMC-induced PVOD in rats represents a unique model to test novel therapies in this devastating orphan disease.
Asunto(s)
Antibióticos Antineoplásicos/efectos adversos , Modelos Animales de Enfermedad , Mitomicina/efectos adversos , Enfermedad Veno-Oclusiva Pulmonar/inducido químicamente , Enfermedad Veno-Oclusiva Pulmonar/diagnóstico , Adulto , Animales , Neoplasias del Ano/diagnóstico , Neoplasias del Ano/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Ratas , Ratas Wistar , Sistema de RegistrosRESUMEN
Pulmonary arterial hypertension (PAH) is a devastating disease affecting lung vasculature. The pulmonary arteries become occluded due to increased proliferation and suppressed apoptosis of the pulmonary artery smooth muscle cells (PASMCs) within the vascular wall. It was recently shown that DNA damage could trigger this phenotype by upregulating poly(ADP-ribose)polymerase 1 (PARP-1) expression, although the exact mechanism remains unclear. In silico analyses and studies in cancer demonstrated that microRNA miR-223 targets PARP-1. We thus hypothesized that miR-223 downregulation triggers PARP-1 overexpression, as well as the proliferation/apoptosis imbalance observed in PAH. We provide evidence that miR-223 is downregulated in human PAH lungs, distal PAs, and isolated PASMCs. Furthermore, using a gain and loss of function approach, we showed that increased hypoxia-inducible factor 1α, which is observed in PAH, triggers this decrease in miR-223 expression and subsequent overexpression of PARP-1 allowing PAH-PASMC proliferation and resistance to apoptosis. Finally, we demonstrated that restoring the expression of miR-223 in lungs of rats with monocrotaline-induced PAH reversed established PAH and provided beneficial effects on vascular remodeling, pulmonary resistance, right ventricle hypertrophy, and survival. We provide evidence that miR-223 downregulation in PAH plays an important role in numerous pathways implicated in the disease and restoring its expression is able to reverse PAH.
Asunto(s)
Hipertensión Pulmonar/metabolismo , MicroARNs/metabolismo , Arteria Pulmonar/metabolismo , Animales , Apoptosis/genética , Proliferación Celular/fisiología , Células Cultivadas , Daño del ADN/fisiología , Regulación hacia Abajo/fisiología , Femenino , Humanos , Hipertensión Pulmonar/inducido químicamente , Hipertrofia Ventricular Derecha/genética , Hipertrofia Ventricular Derecha/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Masculino , Persona de Mediana Edad , Monocrotalina/farmacología , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Poli(ADP-Ribosa) Polimerasa-1 , Poli(ADP-Ribosa) Polimerasas/metabolismo , Arteria Pulmonar/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
BACKGROUND: Endothelial cell (EC) dysfunction plays a central role in the pathogenesis of pulmonary arterial hypertension (PAH), promoting vasoconstriction, smooth muscle proliferation, and inflammation. OBJECTIVES: This study sought to test the hypothesis that nebivolol, a ß1-antagonist and ß2,3-agonist, may improve PAH and reverse the PAH-related phenotype of pulmonary ECs (P-EC). METHODS: We compared the effects of nebivolol with metoprolol, a first-generation ß1-selective ß-blocker, on human cultured PAH and control P-EC proliferation, vasoactive and proinflammatory factor production, and crosstalk with PA smooth muscle cells. We assessed the effects of both ß-blockers in precontracted PA rings. We also compared the effects of both ß-blockers in experimental PAH. RESULTS: PAH P-ECs overexpressed the proinflammatory mediators interleukin-6 and monocyte chemoattractant protein-1, fibroblast growth factor-2, and the potent vasoconstrictive agent endothelin-1 as compared with control cells. This pathological phenotype was corrected by nebivolol but not metoprolol in a dose-dependent fashion. We confirmed that PAH P-EC proliferate more than control cells and stimulate more PA smooth muscle cell mitosis, a growth abnormality that was normalized by nebivolol but not by metoprolol. Nebivolol but not metoprolol induced endothelium-dependent and nitric oxide-dependent relaxation of PA. Nebivolol was more potent than metoprolol in improving cardiac function, pulmonary vascular remodeling, and inflammation of rats with monocrotaline-induced pulmonary hypertension. CONCLUSIONS: Nebivolol could be a promising option for the management of PAH, improving endothelial dysfunction, pulmonary vascular remodeling, and right heart function. Until clinical studies are undertaken, however, routine use of ß-blockers in PAH cannot be recommended.
Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Benzopiranos/uso terapéutico , Endotelio Vascular/efectos de los fármacos , Etanolaminas/uso terapéutico , Hipertensión Pulmonar/tratamiento farmacológico , Remodelación Vascular/efectos de los fármacos , Antagonistas de Receptores Adrenérgicos beta 1/farmacología , Animales , Benzopiranos/farmacología , Comunicación Celular/efectos de los fármacos , Técnicas de Cultivo de Célula , Proliferación Celular , Modelos Animales de Enfermedad , Células Endoteliales/efectos de los fármacos , Endotelio Vascular/patología , Endotelio Vascular/fisiopatología , Etanolaminas/farmacología , Humanos , Hipertensión Pulmonar/patología , Hipertensión Pulmonar/fisiopatología , Masculino , Metoprolol/farmacología , Metoprolol/uso terapéutico , Monocrotalina , Miocitos del Músculo Liso , Nebivolol , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/patología , Arteria Pulmonar/fisiopatología , Ratas , Ratas WistarRESUMEN
BACKGROUND: The vascular remodeling responsible for pulmonary arterial hypertension (PAH) involves predominantly the accumulation of α-smooth muscle actin-expressing mesenchymal-like cells in obstructive pulmonary vascular lesions. Endothelial-to-mesenchymal transition (EndoMT) may be a source of those α-smooth muscle actin-expressing cells. METHODS AND RESULTS: In situ evidence of EndoMT in human PAH was obtained by using confocal microscopy of multiple fluorescent stainings at the arterial level, and by using transmission electron microscopy and correlative light and electron microscopy at the ultrastructural level. Findings were confirmed by in vitro analyses of human PAH and control cultured pulmonary artery endothelial cells. In addition, the mRNA and protein signature of EndoMT was recognized at the arterial and lung level by quantitative real-time polymerase chain reaction and Western blot analyses. We confirmed our human observations in established animal models of pulmonary hypertension (monocrotaline and SuHx). After establishing the first genetically modified rat model linked to BMPR2 mutations (BMPR2(Δ140Ex1/+) rats), we demonstrated that EndoMT is linked to alterations in signaling of BMPR2, a gene that is mutated in 70% of cases of familial PAH and in 10% to 40% of cases of idiopathic PAH. We identified molecular actors of this pathological transition, including twist overexpression and vimentin phosphorylation. We demonstrated that rapamycin partially reversed the protein expression patterns of EndoMT, improved experimental PAH, and decreased the migration of human pulmonary artery endothelial cells, providing the proof of concept that EndoMT is druggable. CONCLUSIONS: EndoMT is linked to alterations in BPMR2 signaling and is involved in the occlusive vas cular remodeling of PAH, findings that may have therapeutic implications.
Asunto(s)
Transdiferenciación Celular , Células Endoteliales/patología , Hipertensión Pulmonar/patología , Mesodermo/patología , Actinas/biosíntesis , Actinas/genética , Animales , Biomarcadores , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/biosíntesis , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , Movimiento Celular , Células Cultivadas , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Humanos , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/genética , Hipoxia/complicaciones , Pulmón/irrigación sanguínea , Pulmón/metabolismo , Pulmón/patología , Monocrotalina/toxicidad , Mutación , ARN Mensajero/biosíntesis , Ratas , Sirolimus/farmacología , Remodelación Vascular , Vimentina/biosíntesis , Vimentina/genéticaRESUMEN
Pulmonary veno-occlusive disease (PVOD) is an uncommon form of pulmonary hypertension (PH) characterized by progressive obstruction of small pulmonary veins and a dismal prognosis. Limited case series have reported a possible association between different chemotherapeutic agents and PVOD. We evaluated the relationship between chemotherapeutic agents and PVOD. Cases of chemotherapy-induced PVOD from the French PH network and literature were reviewed. Consequences of chemotherapy exposure on the pulmonary vasculature and hemodynamics were investigated in three different animal models (mouse, rat, and rabbit). Thirty-seven cases of chemotherapy-associated PVOD were identified in the French PH network and systematic literature analysis. Exposure to alkylating agents was observed in 83.8% of cases, mostly represented by cyclophosphamide (43.2%). In three different animal models, cyclophosphamide was able to induce PH on the basis of hemodynamic, morphological, and biological parameters. In these models, histopathological assessment confirmed significant pulmonary venous involvement highly suggestive of PVOD. Together, clinical data and animal models demonstrated a plausible cause-effect relationship between alkylating agents and PVOD. Clinicians should be aware of this uncommon, but severe, pulmonary vascular complication of alkylating agents.
Asunto(s)
Antineoplásicos Alquilantes/efectos adversos , Ciclofosfamida/efectos adversos , Hemodinámica/efectos de los fármacos , Hipertensión Pulmonar , Venas Pulmonares , Animales , Antineoplásicos Alquilantes/uso terapéutico , Ciclofosfamida/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Humanos , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/metabolismo , Hipertensión Pulmonar/patología , Hipertensión Pulmonar/fisiopatología , Masculino , Ratones , Venas Pulmonares/metabolismo , Venas Pulmonares/patología , Venas Pulmonares/fisiopatología , Conejos , RatasRESUMEN
BACKGROUND: The outcome of patients suffering from pulmonary arterial hypertension (PAH) are predominantly determined by the response of the right ventricle to the increase afterload secondary to high vascular pulmonary resistance. However, little is known about the effects of the current available or experimental PAH treatments on the heart. Recently, inflammation has been implicated in the pathophysiology of PAH. N-acetylcysteine (NAC), a well-known safe anti-oxidant drug, has immuno-modulatory and cardioprotective properties. We therefore hypothesized that NAC could reduce the severity of pulmonary hypertension (PH) in rats exposed to monocrotaline (MCT), lowering inflammation and preserving pulmonary vascular system and right heart function. METHODS: Saline-treated control, MCT-exposed, MCT-exposed and NAC treated rats (day 14-28) were evaluated at day 28 following MCT for hemodynamic parameters (right ventricular systolic pressure, mean pulmonary arterial pressure and cardiac output), right ventricular hypertrophy, pulmonary vascular morphometry, lung inflammatory cells immunohistochemistry (monocyte/macrophages and dendritic cells), IL-6 expression, cardiomyocyte hypertrophy and cardiac fibrosis. RESULTS: The treatment with NAC significantly decreased pulmonary vascular remodeling, lung inflammation, and improved total pulmonary resistance (from 0.71 ± 0.05 for MCT group to 0.50 ± 0.06 for MCT + NAC group, p < 0.05). Right ventricular function was also improved with NAC treatment associated with a significant decrease in cardiomyocyte hypertrophy (625 ± 69 vs. 439 ± 21 µm2 for MCT and MCT + NAC group respectively, p < 0.001) and heart fibrosis (14.1 ± 0.8 vs. 8.8 ± 0.1% for MCT and MCT + NAC group respectively, p < 0.001). CONCLUSIONS: Through its immuno-modulatory and cardioprotective properties, NAC has beneficial effect on pulmonary vascular and right heart function in experimental PH.