RESUMEN
OBJECTIVE: This study aimed to investigate the current status and performance of machine learning (ML) approaches in providing reproducible treatment response predictions. METHODS: This systematic review was conducted in accordance with the PRISMA statement and the CHARMS checklist. We searched PubMed, Cochrane Library, Web of Science, Scopus, and EBSCO databases for cohort studies that derived and/or validated ML models focused on predicting rheumatoid arthritis (RA) treatment response. We extracted data and critically appraised studies based on the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) and Prediction Model Risk of Bias Assessment Tool (PROBAST) guidelines. RESULTS: From 210 unduplicated records identified by the literature search, we retained 29 eligible studies. Of these studies, 10 developed a predictive model and reported a mean adherence to the TRIPOD guidelines of 45.6 % (95 % CI: 38.3-52.8 %). The remaining 19 studies not only developed a predictive model but also validated it externally, with a mean adherence of 42.9 % (95 % CI: 39.1-46.6 %). Most of the articles had an unclear risk of bias (41.4 %), followed by a high risk of bias, which was present in 37.9 %. CONCLUSIONS: In recent years, ML methods have been increasingly used to predict treatment response in RA. Our critical appraisal revealed unclear and high risk of bias in most of the identified models, suggesting that researchers can do more to address the risk of bias and increase transparency, including the use of calibration measures and reporting methods for handling missing data. FUNDING: None.
Asunto(s)
Antirreumáticos , Artritis Reumatoide , Aprendizaje Automático , Artritis Reumatoide/tratamiento farmacológico , Humanos , Antirreumáticos/uso terapéutico , Resultado del Tratamiento , PronósticoRESUMEN
Nitric oxide (NO) represents a crucial mediator to regulate cerebral blood flow (CBF) in the human brain both under basal conditions and in response to somatosensory stimulation. An increase in intracellular Ca2+ concentrations ([Ca2+]i) stimulates the endothelial NO synthase to produce NO in human cerebrovascular endothelial cells. Therefore, targeting the endothelial ion channel machinery could represent a promising strategy to rescue endothelial NO signalling in traumatic brain injury and neurodegenerative disorders. Allyl isothiocyanate (AITC), a major active constituent of cruciferous vegetables, was found to increase CBF in non-human preclinical models, but it is still unknown whether it stimulates NO release in human brain capillary endothelial cells. In the present investigation, we showed that AITC evoked a Ca2+-dependent NO release in the human cerebrovascular endothelial cell line, hCMEC/D3. The Ca2+ response to AITC was shaped by both intra- and extracellular Ca2+ sources, although it was insensitive to the pharmacological blockade of transient receptor potential ankyrin 1, which is regarded to be among the main molecular targets of AITC. In accord, AITC failed to induce transmembrane currents or to elicit membrane hyperpolarization, although NS309, a selective opener of the small- and intermediate-conductance Ca2+-activated K+ channels, induced a significant membrane hyperpolarization. The AITC-evoked Ca2+ signal was triggered by the production of cytosolic, but not mitochondrial, reactive oxygen species (ROS), and was supported by store-operated Ca2+ entry (SOCE). Conversely, the Ca2+ response to AITC did not require Ca2+ mobilization from the endoplasmic reticulum, lysosomes or mitochondria. However, pharmacological manipulation revealed that AITC-dependent ROS generation inhibited plasma membrane Ca2+-ATPase (PMCA) activity, thereby attenuating Ca2+ removal across the plasma membrane and resulting in a sustained increase in [Ca2+]i. In accord, the AITC-evoked NO release was driven by ROS generation and required ROS-dependent inhibition of PMCA activity. These data suggest that AITC could be exploited to restore NO signalling and restore CBF in brain disorders that feature neurovascular dysfunction.
Asunto(s)
Células Endoteliales , Óxido Nítrico , Humanos , Especies Reactivas de Oxígeno/metabolismo , Células Endoteliales/metabolismo , Óxido Nítrico/metabolismo , Línea CelularRESUMEN
Introduction: Endothelial cells (ECs), being located at the interface between flowing blood and vessel wall, maintain cardiovascular homeostasis by virtue of their ability to integrate chemical and physical cues through a spatio-temporally coordinated increase in their intracellular Ca2+ concentration ([Ca2+]i). Endothelial heterogeneity suggests the existence of spatially distributed functional clusters of ECs that display different patterns of intracellular Ca2+ response to extracellular inputs. Characterizing the overall Ca2+ activity of the endothelial monolayer in situ requires the meticulous analysis of hundreds of ECs. This complex analysis consists in detecting and quantifying the true Ca2+ events associated to extracellular stimulation and classifying their intracellular Ca2+ profiles (ICPs). The injury assay technique allows exploring the Ca2+-dependent molecular mechanisms involved in angiogenesis and endothelial regeneration. However, there are true Ca2+ events of nearly undetectable magnitude that are almost comparable with inherent instrumental noise. Moreover, undesirable artifacts added to the signal by mechanical injury stimulation complicate the analysis of intracellular Ca2+ activity. In general, the study of ICPs lacks uniform criteria and reliable approaches for assessing these highly heterogeneous spatial and temporal events. Methods: Herein, we present an approach to classify ICPs that consists in three stages: 1) identification of Ca2+ candidate events through thresholding of a feature termed left-prominence; 2) identification of non-true events, known as artifacts; and 3) ICP classification based upon event temporal location. Results: The performance assessment of true-events identification showed competitive sensitivity = [0.9995, 0.9831], specificity = [0.9946, 0.7818] and accuracy = [0.9978, 0.9579] improvements of 2x and 14x, respectively, compared with other methods. The ICP classifier enhanced by artifact detection showed 0.9252 average accuracy with the ground-truth sets provided for validation. Discussion: Results indicate that our approach ensures sturdiness to experimental protocol maneuvers, besides it is effective, simple, and configurable for different studies that use unidimensional time dependent signals as data. Furthermore, our approach would also be effective to analyze the ICPs generated by other cell types, other dyes, chemical stimulation or even signals recorded at higher frequency.
RESUMEN
Type 2 Diabetes Mellitus (T2DM) is a rapidly rising disease with cardiovascular complications constituting the most common cause of death among diabetic patients. Chronic hyperglycemia can induce vascular dysfunction through damage of the components of the vascular wall, such as vascular smooth muscle cells (VSMCs), which regulate vascular tone and contribute to vascular repair and remodeling. These functions are dependent on intracellular Ca2+ changes. The mechanisms by which T2DM affects Ca2+ handling in VSMCs still remain poorly understood. Therefore, the objective of this study was to determine whether and how T2DM affects Ca2+ homeostasis in VSMCs. We evaluated intracellular Ca2+ signaling in VSMCs from Zucker Diabetic Fatty rats using Ca2+ imaging with Fura-2/AM. Our results indicate that T2DM decreases Ca2+ release from the sarcoplasmic reticulum (SR) and increases the activity of store-operated channels (SOCs). Moreover, we were able to identify an enhancement of the activity of the main Ca2+ extrusion mechanisms (SERCA, PMCA and NCX) during the early stage of the decay of the ATP-induced Ca2+ transient. In addition, we found an increase in Ca2+ entry through the reverse mode of NCX and a decrease in SERCA and PMCA activity during the late stage of the signal decay. These effects were appreciated as a shortening of ATP-induced Ca2+ transient during the early stage of the decay, as well as an increase in the amplitude of the following plateau. Enhanced cytosolic Ca2+ activity in VSMCs could contribute to vascular dysfunction associated with T2DM.
RESUMEN
BACKGROUND: Patients with systemic lupus erythematosus (SLE) have an increased cardiovascular (CV) risk. Insulin resistance (IR), which is higher in patients with SLE, adversely impacts left ventricular (LV) remodeling and function. The aims were to determine LV dysfunction and evaluate the influence of potential risk factors on subclinical LV dysfunction in women with SLE, including IR. METHODS: This cross-sectional study included adult women with SLE without diabetes mellitus (DM), hypertension or severe obesity. Diastolic dysfunction (DD) was verified according to current guidelines. Insulin resistance was estimated using the Quantose score. RESULTS: We included 77 women. The frequency of IR was 65%. All participants had a normal ejection fraction (EF), and 11 (15.7%) had abnormal LV global longitudinal strain (GLS). Twenty-three (32.8%) had DD. The GLS% and global circumferential strain (GCS)% did not differ in patients with and without IR (-20.8 ± 3.1 vs -20.5 ± 2.1; p = 0.61 and -27.9 ± 4.4 vs -27.4 ± 3.7; p = 0.57, respectively). The prevalence of DD was 38.1% in patients with IR versus 25% in those without (p = 0.30). E/e' and E/A ratios did not differ between groups (6.6 ± 1.9 vs 6.6 ± 1.5; p = 0.98 and 1.3 ± 0.3 vs 1.3 ± 0.2; p = 0.27). Higher BMI (OR: 1.2, 95% CI 1.1-1.5) and disease duration (OR: 1.2, 95% CI 1.1-1.4) were associated with DD. CONCLUSIONS: Patients with overweight/obesity may be at higher risk of LV dysfunction. Although IR was high in our patients with SLE was not associated with systolic dysfunction or DD. Body mass index and disease duration were associated with an increased risk of DD.
Asunto(s)
Resistencia a la Insulina , Lupus Eritematoso Sistémico , Disfunción Ventricular Izquierda , Humanos , Adulto , Femenino , Índice de Masa Corporal , Estudios Transversales , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/epidemiología , Disfunción Ventricular Izquierda/epidemiología , Disfunción Ventricular Izquierda/etiología , Remodelación Ventricular , Función Ventricular Izquierda , Volumen SistólicoRESUMEN
OBJECTIVE: Cardiovascular (CV) morbidity is a well-established problem in systemic lupus erythematosus (SLE). Antimalarial (AM) therapy has been seen as a potential atheroprotective agent. The aim was to assess the impact of AM therapy on traditional and novel atherosclerosis (AT) biomarkers in patients with SLE. METHODS: A search of MEDLINE, EMbase, and Cochrane library for studies evaluating the impact of AM on AT biomarkers in SLE was conducted. Data extraction included serum, functional and structural traditional and novel biomarkers. A narrative synthesis of the findings and a meta-analysis with random effects was conducted estimating mean differences (MD), OR, HR and 95% CIs. RESULTS: The search strategy produced 148 articles, of which 64 were extracted for analysis. The MD in VLDL-cholesterol (-10.29, 95% CI -15.35, 5.24), triglycerides (-15.68, 95% CI -27.51, -3.86), and diastolic BP (-3.42, 95% CI -5.62, -1.23) differed significantly in patients on AM therapy compared with those without AM therapy. Patients on AM had a lower prevalence and incidence of diabetes mellitus than patients not on AM (HR: 0.39, 95% CI 0.17, 0.88). HCQ use was associated with lower blood pressure (BP) variability. Structural markers like carotid intima-media thickness (IMT), carotid plaque (CP) and coronary artery calcification (CAC) were not influenced by AM. For functional markers like endothelial and arterial stiffness the benefit was unclear. The GRADE approach showed a very low-to-low quality of evidence (QoE) per outcome. CONCLUSIONS: There is some evidence on the associations between AM therapy and some AT markers. However, the data on which this conclusion was based was of low to very low evidence.
Asunto(s)
Antimaláricos , Aterosclerosis , Lupus Eritematoso Sistémico , Antimaláricos/uso terapéutico , Aterosclerosis/diagnóstico , Aterosclerosis/epidemiología , Biomarcadores , Grosor Intima-Media Carotídeo , Humanos , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/tratamiento farmacológico , Factores de RiesgoRESUMEN
BACKGROUND AND AIMS: Non-invasive surrogates of cardiovascular (CV) disease such as endothelial dysfunction (ED) and peripheral arterial stiffness (AS) have been evaluated in systemic lupus erythematosus (SLE) patients. The aim of this study was to systematically review and meta-analyze reports of cardiovascular disease (CVD) in SLE patients, as measured by ED and AS. METHODS: Studies analyzing the relationship of SLE with ED (flow-mediated dilatation [FMD], nitroglycerin-mediated dilatation [NMD] and peripheral arterial tonometry [PAT]) and AS (augmentation index [AIx], pulse wave velocity [PWV]) were systematically searched for in PubMed, Cochrane library, EMBASE, VHL, SciELO and Web of Science databases. Inclusion criteria included peer-review and English language. Mean differences (MD) and 95% confidence intervals (CIs) were estimated using the random effect model. The study was registered with PROSPERO, number CRD42019121068. RESULTS: The meta-analysis included 49 studies. FMD data from 18 studies including 943 SLE subjects (mean age = 38.71 [95%CI 36.21, 41.21] years) and 644 unaffected controls (mean age = 38.63 [95%CI 36.11, 41.15] years) were included. When compared with unaffected controls, FMD in SLE subjects was decreased by 4.3% (95%CI: -6.13%, -2.47%): p < 0.001). However, NMD did not significantly differ between SLE patients and controls (MD = - 2.68%; 95% CI -6.00, 0.62; p = 0.11). A significantly increased AS between SLE patients and controls according to overall PWV (MD = 1.12 m/s; 95% CI 0.72-1.52; p < 0.001) was observed, but not for the brachial-ankle PWV. AIx was also increased in SLE patients compared with healthy controls (MD = 4.55%; 95% CI 1.48-7.63; p = 0.003). CONCLUSIONS: Overall, SLE patients showed impaired FMD, an independent predictor of CV events. There was a higher degree of AS in SLE patients compared with controls. ED and AS in SLE should be considered when planning preventive strategies and therapies.
Asunto(s)
Enfermedades Cardiovasculares/fisiopatología , Endotelio Vascular/fisiopatología , Lupus Eritematoso Sistémico/fisiopatología , Rigidez Vascular , Adulto , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Femenino , Factores de Riesgo de Enfermedad Cardiaca , Humanos , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/epidemiología , Masculino , Pronóstico , Medición de RiesgoRESUMEN
The neuromodulator histamine is able to vasorelax in human cerebral, meningeal and temporal arteries via endothelial histamine 1 receptors (H1 Rs) which result in the downstream production of nitric oxide (NO), the most powerful vasodilator transmitter in the brain. Although endothelial Ca 2+ signals drive histamine-induced NO release throughout the peripheral circulation, the mechanism by which histamine evokes NO production in human cerebrovascular endothelial cells is still unknown. Herein, we exploited the human cerebral microvascular endothelial cell line, hCMEC/D3, to assess the role of intracellular Ca 2+ signaling in histamine-induced NO release. To achieve this goal, hCMEC/D3 cells were loaded with the Ca 2+ - and NO-sensitive dyes, Fura-2/AM and DAF-FM/AM, respectively. Histamine elicited repetitive oscillations in intracellular Ca 2+ concentration in hCMEC/D3 cells throughout a concentration range spanning from 1 pM up to 300 µM. The oscillatory Ca 2+ response was suppressed by the inhibition of H 1 Rs with pyrilamine, whereas H 1 R was abundantly expressed at the protein level. We further found that histamine-induced intracellular Ca 2+ oscillations were initiated by endogenous Ca 2+ mobilization through inositol-1,4,5-trisphosphate- and nicotinic acid dinucleotide phosphate-sensitive channels and maintained over time by store-operated Ca 2+ entry. In addition, histamine evoked robust NO release that was prevented by interfering with the accompanying intracellular Ca 2+ oscillations, thereby confirming that the endothelial NO synthase is recruited by Ca 2+ spikes also in hCMEC/D3 cells. These data provide the first evidence that histamine evokes NO production from human cerebrovascular endothelial cells through intracellular Ca 2+ oscillations, thereby shedding novel light on the mechanisms by which this neuromodulator controls cerebral blood flow.
Asunto(s)
Encéfalo/irrigación sanguínea , Calcio/metabolismo , Células Endoteliales/efectos de los fármacos , Histamina/farmacología , Microvasos/citología , Óxido Nítrico/metabolismo , Línea Celular , Células Endoteliales/metabolismo , Agonistas de los Receptores Histamínicos/farmacología , Humanos , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , NADP/análogos & derivados , NADP/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismoRESUMEN
OBJECTIVE: A protective function of vitamin D in metabolic syndrome (MetS) has been described. The objective of the present study was to examine the relationship between serum 25-hydroxyvitamin D (25(OH)D) concentrations and MetS in non-diabetic systemic lupus erythematosus (SLE) women. METHODS: Cross-sectional analyses of the relationship between concentrations of 25(OH)D, MetS, and its components were made in 160 non-diabetic SLE women. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria. Serum 25(OH)D was measured by chemiluminescent immunoassay. Serum 25(OH)D concentrations were categorized into quartiles (<16.6, 16.6-21.1, 21.2-26.3, ≥26.4 ng/mL). RESULTS: A total of 79 (49.3%) SLE women had MetS. Without adjusting for body mass index (BMI) or smoking, the odds of having MetS decreased according to increasing quartiles of 25(OH)D concentrations (P for trend = .03). The odds ratio (OR) of having MetS was 0.4 (95% confidence interval: 0.2-0.9, P = .04) for the highest vs the lowest quartile of 25(OH)D concentrations when adjusted by age. The crude OR of having elevated hypertriglyceridemia decreased according to increasing quartiles of 25(OH)D concentrations (P for trend = .036). However, further adjustments for BMI and smoking removed the inverse association between 25(OH)D concentrations and MetS and its individual components. CONCLUSION: In non-diabetic SLE women with mild activity, 25(OH)D concentrations are not associated with MetS and its components.
Asunto(s)
Lupus Eritematoso Sistémico/sangre , Síndrome Metabólico/etiología , Vitamina D/análogos & derivados , Adulto , Biomarcadores/sangre , Estudios Transversales , Femenino , Humanos , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Síndrome Metabólico/sangre , Síndrome Metabólico/diagnóstico , Persona de Mediana Edad , Pronóstico , Medición de Riesgo , Factores de Riesgo , Vitamina D/sangreRESUMEN
It has long been known that the conditionally essential polyunsaturated arachidonic acid (AA) regulates cerebral blood flow (CBF) through its metabolites prostaglandin E2 and epoxyeicosatrienoic acid, which act on vascular smooth muscle cells and pericytes to vasorelax cerebral microvessels. However, AA may also elicit endothelial nitric oxide (NO) release through an increase in intracellular Ca2+ concentration ([Ca2+]i). Herein, we adopted Ca2+ and NO imaging, combined with immunoblotting, to assess whether AA induces intracellular Ca2+ signals and NO release in the human brain microvascular endothelial cell line hCMEC/D3. AA caused a dose-dependent increase in [Ca2+]i that was mimicked by the not-metabolizable analogue, eicosatetraynoic acid. The Ca2+ response to AA was patterned by endoplasmic reticulum Ca2+ release through type 3 inositol-1,4,5-trisphosphate receptors, lysosomal Ca2+ mobilization through two-pore channels 1 and 2 (TPC1-2), and extracellular Ca2+ influx through transient receptor potential vanilloid 4 (TRPV4). In addition, AA-evoked Ca2+ signals resulted in robust NO release, but this signal was considerably delayed as compared to the accompanying Ca2+ wave and was essentially mediated by TPC1-2 and TRPV4. Overall, these data provide the first evidence that AA elicits Ca2+-dependent NO release from a human cerebrovascular endothelial cell line, but they seemingly rule out the possibility that this NO signal could acutely modulate neurovascular coupling.
Asunto(s)
Ácido Araquidónico/farmacología , Señalización del Calcio , Calcio/metabolismo , Células Endoteliales/efectos de los fármacos , Óxido Nítrico/metabolismo , Encéfalo/irrigación sanguínea , Canales de Calcio/metabolismo , Células Cultivadas , Células Endoteliales/metabolismo , Endotelio Vascular/citología , Humanos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Microcirculación , Canales Catiónicos TRPV/metabolismoRESUMEN
An increase in intracellular Ca2+ concentration ([Ca2+]i) plays a key role in controlling endothelial functions; however, it is still unclear whether endothelial Ca2+ handling is altered by type 2 diabetes mellitus, which results in severe endothelial dysfunction. Herein, we analyzed for the first time the Ca2+ response to the physiological autacoid ATP in native aortic endothelium of obese Zucker diabetic fatty (OZDF) rats and their lean controls, which are termed LZDF rats. By loading the endothelial monolayer with the Ca2+-sensitive fluorophore, Fura-2/AM, we found that the endothelial Ca2+ response to 20 µM and 300 µM ATP exhibited a higher plateau, a larger area under the curve and prolonged duration in OZDF rats. The "Ca2+ add-back" protocol revealed no difference in the inositol-1,4,5-trisphosphate-releasable endoplasmic reticulum (ER) Ca2+ pool, while store-operated Ca2+ entry was surprisingly down-regulated in OZDF aortae. Pharmacological manipulation disclosed that sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) activity was down-regulated by reactive oxygen species in native aortic endothelium of OZDF rats, thereby exaggerating the Ca2+ response to high agonist concentrations. These findings shed new light on the mechanisms by which type 2 diabetes mellitus may cause endothelial dysfunction by remodeling the intracellular Ca2+ toolkit.
Asunto(s)
Aorta/metabolismo , Calcio/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Endotelio Vascular/metabolismo , Animales , Señalización del Calcio/fisiología , Diabetes Mellitus Experimental , Modelos Animales de Enfermedad , Retículo Endoplásmico/metabolismo , Fura-2/análogos & derivados , Prueba de Tolerancia a la Glucosa , Homeostasis , Resistencia a la Insulina , Masculino , ATPasas Transportadoras de Calcio de la Membrana Plasmática/metabolismo , Ratas , Ratas Zucker , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Intercambiador de Sodio-Calcio/metabolismoRESUMEN
Endothelial cells perform a wide variety of fundamental functions for the cardiovascular system, their proliferation and migration being strongly regulated by their intracellular calcium concentration. Hence it is extremely important to carefully measure endothelial calcium signals under different stimuli. A proposal to automate the intracellular calcium profiles extraction from fluorescence image sequences is presented. Digital image processing techniques were combined with a multi-target tracking approach supported by Kalman estimation. The system was tested with image sequences from two different stimuli. The first one was a chemical stimulus, that is, ATP, which caused small movements in the cells trajectories, thereby suggesting that the bath application of the agonist does not generate significant artifacts. The second one was a mechanical stimulus delivered by a glass microelectrode, which caused major changes in cell trajectories. The importance of the tracking block is evidenced since more accurate profiles were extracted, mainly for cells closest to the stimulated area. Two important contributions of this work are the automatic relocation of the region of interest assigned to the cells and the possibility of data extraction from big image sets in efficient and expedite way. The system may adapt to different kind of cell images and may allow the extraction of other useful features.
Asunto(s)
Calcio/metabolismo , Células Endoteliales/metabolismo , Procesamiento de Imagen Asistido por Computador , Espacio Intracelular/metabolismo , Adenosina Trifosfato/metabolismo , Algoritmos , Animales , Automatización , Fluorescencia , Masculino , Ratas WistarRESUMEN
Lung surfactant is a complex mixture of phospholipids and specific proteins but its role in the pathogenesis of interstitial lung diseases is not established. Herein, we analyzed the effects of three representative phospholipid components, that is, dipalmitoilphosphatidylcoline (DPPC), phosphatidylglycerol (PG) and phosphatidylethanolamine (PE), on collagen expression, apoptosis and Ca2+ signaling in normal human lung fibroblasts (NHLF) and probed their effect in an experimental model of lung fibrosis. Collagen expression was measured with RT-PCR, apoptosis was measured by using either the APOPercentage assay kit (Biocolor Ltd., Northern Ireland, UK) or the Caspase-Glo 3/7 assay (Promega, Madison, WI, USA) and Ca2+ signaling by conventional epifluorescence imaging. The effect in vivo was tested in bleomycin-induced lung fibrosis in mice. DPPC and PG did not affect collagen expression, which was downregulated by PE. Furthermore, PE promoted apoptosis and induced a dose-dependent Ca2+ signal. PE-induced Ca2+ signal and apoptosis were both blocked by phospholipase C, endoplasmic reticulum pump and store-operated Ca2+ entry inhibition. PE-induced decrease in collagen expression was attenuated by blocking phospholipase C. Finally, surfactant enriched with PE and PE itself attenuated bleomycin-induced lung fibrosis and decreased the soluble collagen concentration in mice lungs. This study demonstrates that PE strongly contributes to the surfactant-induced inhibition of collagen expression in NHLF through a Ca2+ signal and that early administration of Beractant enriched with PE diminishes lung fibrosis in vivo.
Asunto(s)
Bleomicina/efectos adversos , Fibroblastos/metabolismo , Fosfatidiletanolaminas/metabolismo , Fibrosis Pulmonar/etiología , Fibrosis Pulmonar/metabolismo , Animales , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Colágeno/genética , Colágeno/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Fibroblastos/efectos de los fármacos , Fibroblastos/patología , Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Ratones , Fosfatidiletanolaminas/farmacología , Fibrosis Pulmonar/tratamiento farmacológico , Fibrosis Pulmonar/patología , Surfactantes Pulmonares/metabolismoRESUMEN
The role of Na(+)-Ca(2+) exchanger (NCX) in vascular endothelium is still matter of debate. Depending on both the endothelial cell (EC) type and the extracellular ligand, NCX has been shown to operate in either the forward (Ca(2+) out)- or the reverse (Ca(2+) in)-mode. In particular, acetylcholine (Ach) has been shown to promote Ca(2+) inflow in the intact endothelium of excised rat aorta. Herein, we assessed the involvement of NCX into the Ca(2+) signals elicited by ATP in such preparation. Removal of extracellular Na(+) (0Na(+)) causes the NCX to switch into the reverse-mode and induced an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), which disappeared in the absence of extracellular Ca(2+), and in the presence of benzamil, which blocks both modes of NCX, and KB-R 7943, a selective inhibitor of the reverse-mode. ATP induced a transient Ca(2+) signal, whose decay was significantly prolonged by 0Na(+), benzamil, DCB, and monensin while it was unaffected by KB-R 7943. Notably, lowering extracellular Na(+) concentration increased the sensibility to lower doses of ATP. These date suggest that, unlike Ach-stimulated ECs, NCX promotes Ca(2+) extrusion when the stimulus is provided by ATP in intact endothelium of rat aorta. These data show that, within the same preparation, NCX operates in both modes, depending on the chemical nature of the extracellular stimulus.
Asunto(s)
Aorta/metabolismo , Calcio/metabolismo , Endotelio Vascular/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Adenosina Trifosfato/farmacología , Amilorida/análogos & derivados , Amilorida/farmacología , Animales , Aorta/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Técnicas In Vitro , Ratas , Ratas Wistar , Intercambiador de Sodio-Calcio/antagonistas & inhibidores , Tiourea/análogos & derivados , Tiourea/farmacologíaRESUMEN
The mechanism whereby extracellular Ca(2+) exerts the endothelium-dependent control of vascular tone is still unclear. In this study, we assessed whether cardiac microvascular endothelial cells (CMEC) express a functional extracellular Ca(2+)-sensing receptor (CaSR) using a variety of techniques. CaSR mRNA was detected using RT-PCR, and CaSR protein was identified by immunocytochemical analysis. In order to assess the functionality of the receptor, CMEC were loaded with the Ca(2+)-sensitive fluorochrome, Fura-2/AM. A number of CaSR agonists, such as spermine, Gd(3+), La(3+) and neomycin, elicited a heterogeneous intracellular Ca(2+) signal, which was abolished by disruption of inositol 1,4,5-trisphosphate (InsP(3)) signaling and by depletion of intracellular stores with cyclopiazonic acid. The inhibition of the Na(+)/Ca(2+) exchanger upon substitution of extracellular Na(+) unmasked the Ca(2+) signal triggered by an increase in extracellular Ca(2+) levels. Finally, aromatic amino acids, which function as allosteric activators of CaSR, potentiated the Ca(2+) response to the CaSR agonist La(3+). These data provide evidence that CMEC express CaSR, which is able to respond to physiological agonists by mobilizing Ca(2+) from intracellular InsP(3)-sensitive stores.