In vitro 3D co-culture model of human endothelial and smooth muscle cells to study pathological vascular remodeling. / Modelo de cocultivo 3D in vitro de células endoteliales y vasculares de músculo liso humanas para el estudio del remodelado vascular patológico.

Pathological vascular remodeling of the vessel wall refers to the structural and functional changes of the vessel wall that occur in response to injury that eventually leads to cardiovascular disease. The vessel wall is composed of two main types of cells, endothelial cells and vascular smooth muscle cells, whose communication is crucial in both the development of the vasculature and the homeostasis of mature vessels. Changes in the dialogue between endothelial cells and vascular smooth muscle cells are associated with various pathological states that triggers remodeling of the vascular wall. For many years, considerable efforts have been made to develop effective diagnoses and treatments for these pathologies by studying their mechanisms in both in vitro and in vivo models. Compared to animal models, in vitro models can provide great opportunities to obtain data in a more homogeneous, economical and massive way, providing an overview of the signaling pathways responsible for these pathologies. The implementation of three-dimensional in vitro co-culture models for the study of other pathologies has been postulated as a potentially applicable methodology, which determines the importance of its application in studies of cardiovascular diseases. In this article we present a method for culturing human endothelial cells and vascular smooth muscle cells, grown under non-adherent conditions, that generate three-dimensional spheroidal structures with greater physiological equivalence to in vivo conditions. This in vitro modeling could be used as a study tool to identify cellular and molecular mechanisms involved in the pathological processes underlying vascular remodeling.

Remodelado vascular excéntrico: su relación con trastornos metabólicos y el incremento de la masa corporal / Eccentric Vascular Remodeling: Its Relationship with Metabolic Disorders and Increased Body Mass

RESUMEN Introducción: Existe evidencia reciente que establecería a la hipoperfusión muscular como causa primaria de trastornos metabólicos en respuesta a la sobrealimentación. Esta concepción centrípeta del desarrollo de trastornos metabólicos podría implicar no solo alteraciones en la microvasculatura, sino también afectación en las arterias de conductancia. Objetivos: 1) Determinar la asociación entre diámetro basal de la arteria humeral (D-Hum) y la vasodilatación mediada por flujo (VDMF) 2) Analizar la asociación de ambos parámetros conforme aumenta de la masa corporal 3) Evaluar asociaciones entre el D-Hum/VDMF con componentes del síndrome metabólico (SM) 4) Evaluar la asociación independiente de ambas variables con el SM. Material y métodos: Se evaluaron 3493 pacientes. Se excluyeron pacientes < 18 y >80 años, con patología cardiovascular previa, insuficiencia renal crónica (IRC), colagenopatías, y tratados con estatinas. Se determinó presión arterial (PA), parámetros antropométricos y perfil metabólico, y se clasificó a los sujetos de acuerdo con la presencia de SM según AHA/NHLBI 2019. Se midieron D-Hum en mm y VDMF en %. Se analizó la asociación lineal entre D-Hum y VDMF y se analizaron ambas variables según decilos de índice de masa corporal (IMC). Se evaluaron asociaciones entre D-Hum/VDMF con la PA, glucemia (Glu), triglicéridos (TG) y colesterol de alta densidad (HDLc). Se realizaron dos regresiones logísticas con SM como variable dependiente y D-Hum o VDMF más edad, sexo, IMC y factores de riesgo coronario (FRC) como independientes. Resultados: Ingresaron 1995 pacientes (48,2 ± 11 años, 56 % hombres). El D-Hum y la VDMF presentaron una asociación inversa (r= -0,42; p < 0,0001). El D-Hum aumentó según decilos del IMC (p < 0,000001); la VDMF mostró relación inversa con los decilos crecientes de IMC (p < 0,000001). El D-Hum presentó correlación directa con PA, Glu y TG; e inversa con HDLc (p < 0,05 en todos los casos). La VDMF mostró correlación inversa con PA, Glu y TG; y directa con HDLc (p < 0,05 en todos los casos). El D-Hum se asoció en forma independiente con el SM ajustado por edad, sexo, IMC y FRC (OR 1,42, p = 0,0019), mientras que la VDMF no (OR 0,98, p = 0,217). Conclusión: El remodelado vascular excéntrico se asoció con un compromiso en la adaptación vascular ante aumentos en la demanda de flujo sanguíneo y con alteraciones metabólicas a lo largo del incremento de la masa corporal. Así, el compromiso dinámico de la vasculatura podría tener un rol determinante en el desarrollo de alteraciones metabólicas en forma sincrónica con la ganancia de peso.

ABSTRACT Background: Recent evidence would establish muscle hypoperfusion as the primary cause of metabolic disorders in response to overfeeding. This centripetal concept on the development of metabolic disorders could involve not only alterations in the microvasculature, but also affect the conductance arteries. Objectives: The aim of this study was 1) to determine the association between baseline brachial artery diameter (BAD) and flow-mediated vasodilation (FMVD), 2) To analyze the association of both parameters throughout the increase in body mass, 3) To evaluate associations between BAD/FMVD with components of the metabolic syndrome (MS) and 4) To evaluate the independent association of both variables with MS. Methods: A total of 3493 patients were evaluated. Patients <18 and >80 years old, those with previous cardiovascular disease, chronic kidney disease (CKD), collagenopathies, or treated with statins were excluded from the study. Blood pressure (BP), anthropometric parameters and metabolic profile were determined, and the subjects were classified according to the presence of MS conforming AHA/NHLBI 2019 criteria. BAD was measured in mm and FMVD as percentage. The linear association between BAD and FMVD was assessed, and both variables were analyzed according to deciles of body mass index (BMI). Associations between BAD/FMVD with BP, glucose (Glu), triglycerides (TG) and high-density cholesterol (HDL-C) levels were evaluated. Two logistic regression analyses were performed with MS as dependent variable and BAD or FMVD plus age, gender, BMI, and coronary risk factors (CRF) as independent variables. Results: A total of 1995 patients (48.2 ± 11 years, 56% men) were admitted in the study. An inverse correlation was found between BAD and FMVD (r= -0.42; p < 0.0001). BAD increased according to deciles of BMI (p < 0.000001), while FMVD showed an inverse relationship with increasing deciles of BMI (p < 0.000001). BAD exhibited a direct correlation with BP, Glu and TG; and an inverse relationship with HDL-C (p < 0.05 in all cases). FMVD presented an inverse correlation with BP, Glu and TG; and a direct correlation with HDL-C (p < 0.05 in all cases). BAD was independently associated with MS adjusted for age, gender, BMI and CRF (OR 1.42, p=0.0019), while FMVD was not (OR 0.98, p = 0.217). Conclusion: Eccentric vascular remodeling was associated with vascular adaptation to increased blood flow demand and with metabolic alterations throughout the increase in body mass. Thus, the dynamic compromise of vasculature could play a decisive role in the development of metabolic alterations occurring synchronously with weight gain.

Evaluación mediante OCT del remodelado vascular pulmonar en insuficiencia cardiaca avanzada. Estudio OCTOPUS-CHF / Optical coherence tomography assessment of pulmonary vascular remodeling in advanced heart failure. The OCTOPUS-CHF study

Introducción y objetivos El remodelado vascular pulmonar es prevalente en la insuficiencia cardiaca avanzada. El cateterismo derecho es la prueba de elección, pero está limitado por la asunción de medidas indirectas, un enfoque de flujo no pulsátil, su dependencia de la carga o la variabilidad en la interpretación. Nuestro objetivo es evaluar la vasculopatía pulmonar mediante tomografía de coherencia óptica (OCT) intravascular y correlacionarla con los parámetros hemodinámicos. Métodos Estudio observacional, prospectivo y multicéntrico que incluyó a 100 pacientes en estudio previo al trasplante cardiaco. Todos se sometieron a un cateterismo derecho con OCT de la arteria pulmonar. Resultados La OCT se pudo analizar en 90 casos. La mediana de edad fue 57,50 [intervalo intercuartílico, 48,75-63,25] años y 71 eran varones (78,88%). La cardiopatía subyacente más frecuente fue la miocardiopatía dilatada no isquémica (33 pacientes [36,66%]). El grosor intimal se correlacionó con la presión arterial pulmonar media, las resistencias vasculares y el gradiente transpulmonar (coeficiente R de 0,42, 0,27 y 0,32 respectivamente). La estimación no invasiva de la presión sistólica pulmonar, el tiempo de aceleración y el acoplamiento ventriculoarterial también se correlacionaron con el grosor intimal (coeficiente R de 0,42, 0,27 y 0,49 respectivamente). Los pacientes con un grosor intimal > 0,25mm presentaron mayores presión pulmonar media (37,00 frente a 25,00mmHg; p=0,004) y resistencias vasculares (3,44 frente a 2,08 UW; p=0,017). Conclusiones La OCT pulmonar es factible y está significativamente asociada con los datos hemodinámicos. La correlación débil indica que el remodelado vascular no explica por completo la hipertensión pulmonar (AU)

Introduction and objectives Pulmonary vascular remodeling is common among patients with advanced heart failure. Right heart catheterization is the gold standard to assess pulmonary hypertension, but is limited by indirect measurement assumptions, a steady-flow view, load-dependency, and interpretation variability. We aimed to assess pulmonary vascular remodeling with intravascular optical coherence tomography (OCT) and to study its correlation with hemodynamic data. Methods This observational, prospective, multicenter study recruited 100 patients with advanced heart failure referred for heart transplant evaluation. All patients underwent right heart catheterization together with OCT evaluation of a subsegmentary pulmonary artery. Results OCT could be performed and properly analyzed in 90 patients. Median age was 57.50 [interquartile range, 48.75-63.25] years and 71 (78.88%) were men. The most frequent underlying heart condition was nonischemic dilated cardiomyopathy (33 patients [36.66%]). Vascular wall thickness significantly correlated with mean pulmonary artery pressure, pulmonary vascular resistance, and transpulmonary gradient (R coefficient=0.42, 0.27 and 0.32 respectively). Noninvasive estimation of pulmonary artery systolic pressure, acceleration time, and right ventricle-pulmonary artery coupling also correlated with wall thickness (R coefficient of 0.42, 0.27 and 0.49, respectively). Patients with a wall thickness over 0.25mm had significantly higher mean pulmonary pressures (37.00 vs 25.00mmHg; P=.004) and pulmonary vascular resistance (3.44 vs 2.08 WU; P=.017). Conclusions Direct morphological assessment of pulmonary vascular remodeling with OCT is feasible and is significantly associated with classic hemodynamic parameters. This weak association suggests that structural remodeling does not fully explain pulmonary hypertension (AU)

Optical coherence tomography assessment of pulmonary vascular remodeling in advanced heart failure. The OCTOPUS-CHF study.

INTRODUCTION AND OBJECTIVES: Pulmonary vascular remodeling is common among patients with advanced heart failure. Right heart catheterization is the gold standard to assess pulmonary hypertension, but is limited by indirect measurement assumptions, a steady-flow view, load-dependency, and interpretation variability. We aimed to assess pulmonary vascular remodeling with intravascular optical coherence tomography (OCT) and to study its correlation with hemodynamic data. METHODS: This observational, prospective, multicenter study recruited 100 patients with advanced heart failure referred for heart transplant evaluation. All patients underwent right heart catheterization together with OCT evaluation of a subsegmentary pulmonary artery. RESULTS: OCT could be performed and properly analyzed in 90 patients. Median age was 57.50 [interquartile range, 48.75-63.25] years and 71 (78.88%) were men. The most frequent underlying heart condition was nonischemic dilated cardiomyopathy (33 patients [36.66%]). Vascular wall thickness significantly correlated with mean pulmonary artery pressure, pulmonary vascular resistance, and transpulmonary gradient (R coefficient=0.42, 0.27 and 0.32 respectively). Noninvasive estimation of pulmonary artery systolic pressure, acceleration time, and right ventricle-pulmonary artery coupling also correlated with wall thickness (R coefficient of 0.42, 0.27 and 0.49, respectively). Patients with a wall thickness over 0.25mm had significantly higher mean pulmonary pressures (37.00 vs 25.00mmHg; P=.004) and pulmonary vascular resistance (3.44 vs 2.08 WU; P=.017). CONCLUSIONS: Direct morphological assessment of pulmonary vascular remodeling with OCT is feasible and is significantly associated with classic hemodynamic parameters. This weak association suggests that structural remodeling does not fully explain pulmonary hypertension.

Gen 15 estimulado por interferón, nexo común del daño vascular en la hipertensión, la obesidad y los aneurismas aórticos / Interferon-stimulated gene 15, a common link of vascular damage in hypertension, obesity and aortic aneurysms

La hipertensión y la obesidad son importantes problemas de salud en todo el mundo con notables consecuencias sobre la morbilidad y la mortalidad. De hecho, tanto la hipertensión como la obesidad son importantes factores de riesgo para el desarrollo de enfermedades cardiovasculares. La disfunción endotelial, el remodelado vascular y las alteraciones en la mecánica vascular son aspectos comunes del daño vascular en la hipertensión, la obesidad y los aneurismas. Durante las últimas décadas, se ha demostrado la importancia de la inflamación de bajo grado en el daño vascular asociado a las enfermedades cardiovasculares. Dicha inflamación se caracteriza por la acumulación de células inflamatorias en la vasculatura, así como por el aumento de citoquinas proinflamatorias locales y circulantes. Por tanto, la identificación de nuevos mediadores inflamatorios implicados en dicho daño se ha convertido en un área de investigación muy importante.El interferón-γ (IFNγ) o el factor de necrosis tumoral-α (TNFα) son importantes citoquinas implicadas en el daño vascular asociado a la hipertensión. Además, se acepta que el TNFα es un mediador clave implicado en la resistencia a la insulina y el daño vascular observado en la obesidad. Ambas citoquinas inducen la expresión del gen 15 estimulado por interferón (ISG15), una proteína similar a la ubiquitina que induce una modificación postraducional reversible (ISGilación) y que también puede secretarse como forma libre. Las funciones de ISG15 están principalmente relacionadas con la respuesta inmune frente a infecciones, sin embargo, podría ser también una interesante nueva diana del daño cardiovascular. (AU)

Hypertension and obesity are major health problems worldwide with significant consequences on morbidity and mortality. In fact, both hypertension and obesity are important risk factors for the development of cardiovascular diseases. Endothelial dysfunction, vascular remodeling, and alterations in vascular mechanics are common aspects of vascular damage in hypertension, obesity, and aneurysms. During the last decades, the importance of low-grade inflammation in vascular damage associated with cardiovascular diseases has been demonstrated. This inflammation is characterized by the accumulation of inflammatory cells in the vasculature, as well as by the increase of local and circulating pro-inflammatory cytokines. Therefore, the identification of new inflammatory mediators involved in this damage has become a very important area of research.Interferón-γ (IFNγ) or tumor necrosis tumoral-α (TNFα) are important cytokines involved in the vascular damage associated with hypertension. Furthermore, it is accepted that TNFα is a key mediator involved in insulin resistance and vascular damage observed in obesity. Both cytokines induce the expression of interferon-stimulated gene 15 (ISG15), a protein similar to ubiquitin that induces a reversible post-translational modification (ISGylation) and that can also be secreted as a free form. The functions of ISG15 are mainly related to the immune response against infections, however, it could also be an interesting new target for cardiovascular damage. (AU)

Receptor mineralocorticoide extrarrenal. Una posible nueva diana para combatir el daño vascular / Extrarenal mineralocorticoid receptor. A potential new target against vascular damage

El receptor mineralocorticoide (MR) y su principal ligando la aldosterona juegan un papel fundamental en la regulación de la presión arterial a través de sus efectos facilitadores de la reabsorción de sodio y agua. Los antagonistas del receptor de la aldosterona son fármacos de probada eficacia, que en la actualidad se utilizan en pacientes seleccionados con hipertensión arterial resistente. Además, estos fármacos aumentan la supervivencia en diversas circunstancias como en la insuficiencia cardiaca, proporcionan protección renal en pacientes con enfermedad renal crónica y tienen efectos beneficiosos adicionales en otras patologías. Más allá de sus efectos cardiorrenales, en la actualidad sabemos que el MR se expresa en otros tejidos como células musculares lisas y endoteliales vasculares mediando efectos deletéreos tales como remodelado vascular, rigidez vascular y disfunción endotelial, los cuales son factores pronósticos de futuros eventos cardiovasculares. Además, nuevas evidencias experimentales demuestran que el MR se expresa también en células adyacentes a la vasculatura como células inmunes y adipocitos a través de los cuales podría influir en la función y estructura vascular. Entre los mecanismos responsables de dichos efectos se incluyen mecanismos genómicos y no genómicos, que facilitan la producción de especies reactivas de oxígeno de distintas fuentes, entre las que destaca la enzima NADPH oxidasa, así como de otros mediadores inflamatorios. En este artículo se revisan las evidencias experimentales y clínicas que sugieren que la activación del MR por aldosterona es un importante mediador de daño vascular a través de la producción de especies reactivas de oxígeno. (AU)

Mineralocorticoid receptor (MR) and its main ligand aldosterone, play a key role in the regulation of blood pressure through their effects increasing sodium and water reabsorption. MR antagonists are effective drugs that are currently used in selected patients with resistant hypertension. In addition, these drugs increase patients survival in specific circumstances such as heart failure, they offer renal protection in chronic kidney disease patients and they have beneficial effects in other pathologies. Besides MR cardiorenal effects, it is now accepted that MR is expressed in other tissues and cells such as vascular smooth muscle cells and endothelial cells where excessive MR activation induces deleterious effects such as vascular remodeling and stiffness and endothelial dysfunction, which are prognostic factors for future cardiovascular events. Moreover, novel evidence demonstrate that MR is also expressed in non-vascular cells adjacent to vessels such as immune cells and adipocytes that might influence vascular function and structure. Among the mechanisms responsible for these effects of MR are genomic and non genomic mechanisms that facilitate reactive oxygen species production mainly from the NADPH oxidase enzyme, as well as production of other inflammatory mediators. Here we review the experimental and clinical evidence that suggest that MR activation by aldosterone is an important mediator of vascular damage through the production of reactive oxygen species. (AU)

Gen 15 estimulado por interferón, nexo común del daño vascular en la hipertensión, la obesidad y los aneurismas aórticos / Interferon-stimulated gene 15, a common link of vascular damage in hypertension, obesity and aortic aneurysms

La hipertensión y la obesidad son importantes problemas de salud en todo el mundo con notables consecuencias sobre la morbilidad y la mortalidad. De hecho, tanto la hipertensión como la obesidad son importantes factores de riesgo para el desarrollo de enfermedades cardiovasculares. La disfunción endotelial, el remodelado vascular y las alteraciones en la mecánica vascular son aspectos comunes del daño vascular en la hipertensión, la obesidad y los aneurismas. Durante las últimas décadas, se ha demostrado la importancia de la inflamación de bajo grado en el daño vascular asociado a las enfermedades cardiovasculares. Dicha inflamación se caracteriza por la acumulación de células inflamatorias en la vasculatura, así como por el aumento de citoquinas proinflamatorias locales y circulantes. Por tanto, la identificación de nuevos mediadores inflamatorios implicados en dicho daño se ha convertido en un área de investigación muy importante. El interferón-γ (IFNγ) o el factor de necrosis tumoral-α (TNFα) son importantes citoquinas implicadas en el daño vascular asociado a la hipertensión. Además, se acepta que el TNFα es un mediador clave implicado en la resistencia a la insulina y el daño vascular observado en la obesidad. Ambas citoquinas inducen la expresión del gen 15 estimulado por interferón (ISG15), una proteína similar a la ubiquitina que induce una modificación postraducional reversible (ISGilación) y que también puede secretarse como forma libre. Las funciones de ISG15 están principalmente relacionadas con la respuesta inmune frente a infecciones, sin embargo, podría ser también una interesante nueva diana del daño cardiovascular.(AU)

Hypertension and obesity are major health problems worldwide with significant consequences on morbidity and mortality. In fact, both hypertension and obesity are important risk factors for the development of cardiovascular diseases. Endothelial dysfunction, vascular remodeling, and alterations in vascular mechanics are common aspects of vascular damage in hypertension, obesity, and aneurysms. During the last decades, the importance of low-grade inflammation in vascular damage associated with cardiovascular diseases has been demonstrated. This inflammation is characterized by the accumulation of inflammatory cells in the vasculature, as well as by the increase of local and circulating pro-inflammatory cytokines. Therefore, the identification of new inflammatory mediators involved in this damage has become a very important area of research. Interferón-γ (IFNγ) or tumor necrosis tumoral-α (TNFα) are important cytokines involved in the vascular damage associated with hypertension. Furthermore, it is accepted that TNFα is a key mediator involved in insulin resistance and vascular damage observed in obesity. Both cytokines induce the expression of interferon-stimulated gene 15 (ISG15), a protein similar to ubiquitin that induces a reversible post-translational modification (ISGylation) and that can also be secreted as a free form. The functions of ISG15 are mainly related to the immune response against infections, however, it could also be an interesting new target for cardiovascular damage.(AU)

Passiflora quadrangularis L. prevents experimental hypertension and vascular remodelling in rats exposed to nitric oxide deficit / Passiflora quadrangularis L. previene la hipertensión experimental y el remodelado vascular en ratas expuestas a déficit de óxido nítrico

Background: Passiflora quadrangularis L. is among the species used in Colombian folk medicine for hypertension, but until now it has not been studied in experimental models. Objectives: To assess the capacity of P. quadrangularis L. EtOH extract to prevent the hypertension and vascular remodelling induced by nitric oxide (NO) deficit in Wistar rats. Methods: The nitric oxide (NO) synthase inhibitor L-NAME (10 mg/kg, i.p (intraperitoneal), every 48h) was administered for seven weeks to the following groups of rats: P. quadrangularis L.75, 150 and 300 mg/kg/d, p.o. (oral route); enalapril as reference agent, 10 mg/kg/d, p.o. and vehicle as control (mixture of propylene glycol 10%, glycerine 10% and polysorbate 2%). Arterial blood pressure (BP) and heart rate (HR) were measured twice a week. After sacrifice, the aortic rings were isolated, contraction was triggered with phenylephrine (PE 10-6 M) and then the relaxant response achieved with cumulative concentrations of acetylcholine (ACh, 10-10 ­ 10-5 M) or sodium nitroprusside (SNP, 10-10 ­ 10-5 M) was assessed. Histopathologic measures of thickness/lumen ratio from both the left ventricle and aorta walls, as well as phytochemical screening, were also performed. Results: As for enalapril, all doses of P. quadrangularis L. prevented the hypertension induced by L-NAME (122±1.2 versus 155±1.3 mmHg at seventh week). P. quadrangularis L. significantly increased the relaxant effect induced by ACh in isolated aorta and decreased the thickness/lumen ratio of aorta wall specimens. Conclusions: P. quadrangularis L. prevents experimental hypertension induced in rats with nitric oxide deficits improving the endothelium vasodilatation response and protecting against vascular remodelling.

Antecedentes: Passiflora quadrangularis L. es una de las especies utilizadas en medicina tradicional en Colombia para la hipertensión pero hasta el momento no se ha evaluado en modelos experimentales. Objetivos: Evaluar la capacidad del extracto etanólico de P. quadrangularis L. para prevenir la hipertensión y el remodelado vascular inducidos por déficit de óxido nítrico (NO) en ratas Wistar. Métodos: El inhibidor de la óxido nítrico (NO) sintasa L-NAME (10 mg/kg, i.p, cada 48 h) se administró durante siete semanas a los siguientes grupos de tratamiento: P. quadrangularis L. 75, 150 y 300 mg/kg/d, p.o; Enalapril como agente de referencia, 10 mg/kg/d, p.o., y vehículo como control (mezcla de propilenglicol 10%, glicerina 10% y polisorbato 2%). Se midió la presión arterial (BP) y la frecuencia cardiaca (HR) dos veces por semana. Después del sacrificio, se aislaron los anillos aórticos, se desencadenó la contracción con fenilefrina (PE 10-6 M) y la respuesta relajante con concentraciones acumulativas de acetilcolina (ACh, 10-10 ­ 10-5 M) o nitroprusiato de sodio (SNP, 10-10 ­ 10-5 M). También se realizaron estudios histopatológicos de la relación entre el espesor y el lumen tanto en el ventrículo izquierdo como en las paredes de la aorta, así como un cribado fitoquímico. Resultados: Enalapril y todas las dosis de P. quadrangularis L. evitaron la hipertensión inducida por L-NAME (122 ± 1,2 frente a 155 ± 1,3 mm Hg a la séptima semana). P. quadrangularis L. aumentó significativamente el efecto relajante inducido por ACh en la aorta aislada y disminuyó la relación entre el espesor y la luz de los especímenes en la pared de la aorta. Conclusiones: P. quadrangularis L. previene la hipertensión experimental inducida por déficit de óxido nítrico en ratas, mejorando la respuesta del endotelio y protegiendo frente al remodelado vascular.

[The nuclear receptor NOR-1 regulates the activation of vascular cells and vascular remodelling in response to hemodynamic stress]. / El receptor nuclear NOR-1 regula la activación de las células vasculares y el remodelado vascular en respuesta a estrés hemodinámico.

INTRODUCTION: Previous studies have shown that the loss of NOR-1 function modulates the activation of vascular smooth muscle cells (VSMC). In this study we use a mouse that over-expresses human NOR-1 in VSMC to analyze the effect of a gain of NOR-1 function on the activation of VSMC and in the hyperplasia of the intima induced by hemodynamic stress. METHODS: To generate the transgenic animal the human NOR-1 cDNA was placed under the control of the SM22α promoter. The expression of NOR-1 was analyzed by real time PCR, Western blot, immunohistochemistry and immunocitochemistry, and NOR-1 functionality was evaluated by luciferase activity assays. The incorporation of tritiated thymidine was determined as a cell proliferation index. The left carotid artery was ligated, and cross-sections were subjected to morphometric and immunostaining analysis. RESULTS: The transgenic mouse exhibited significant levels of human NOR-1 in aorta and carotid arteries. In aortic VSMC from transgenic mice an increase in the transcriptional activity of ciclin D2 was detected, as well as higher proliferative rates and increased levels of the marker Myh10. In these animals, carotid artery ligation induced a greater neointimal formation and a higher stenotic grade than in wild-type animals, in accordance with the labelling detected for Myh10 and phosphorylated Histone H3. CONCLUSIONS: These results reinforce the role of NOR-1 in VSMC proliferation and in vascular remodelling, and allow us to propose this model as a useful tool to study the involvement of NOR-1 in vascular function and in vascular diseases such as atherosclerosis and restenosis.