RESUMEN
Chromosomal structural rearrangements consist of anomalies in genomic architecture that may or may not be associated with genetic material gain and loss. Evaluating the precise breakpoint is crucial from a diagnostic point of view, highlighting possible gene disruption and addressing to appropriate genotype-phenotype association. Structural rearrangements can either occur randomly within the genome or present with a recurrence, mainly due to peculiar genomic features of the surrounding regions. We report about three non-related individuals, harboring chromosomal structural rearrangements interrupting SETBP1, leading to gene haploinsufficiency. Two out of them resulted negative to Chromosomal Microarray Analysis (CMA), being the rearrangement balanced at a microarray resolution. The third one, presenting with a complex three-chromosome rearrangement, had been previously diagnosed with SETBP1 haploinsufficiency due to a partial gene deletion at one of the chromosomal breakpoints. We thoroughly characterized the rearrangements by means of Optical Genome Mapping (OGM) and Whole Genome Sequencing (WGS), providing details about the involved sequences and the underlying mechanisms. We propose structural variants as a recurrent event in SETBP1 haploinsufficiency, which may be overlooked by laboratory routine genomic analyses (CMA and Whole Exome Sequencing) or only partially determined when associated with genomic losses at breakpoints. We finally introduce a possible role of SETBP1 in a Noonan-like phenotype.
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Aberraciones Cromosómicas , Haploinsuficiencia , Humanos , Haploinsuficiencia/genética , Reordenamiento Génico , Cromosomas , Secuenciación Completa del Genoma/métodos , Proteínas Portadoras/genética , Proteínas Nucleares/genéticaRESUMEN
The recurrent 2q13 deletion syndrome is a rare genetic disorder associated with developmental delay, cardiac and urogenital malformations, and minor facial anomalies. Congenital heart defects (CHDs) are the most frequent malformations associated with del2q13. Experimental studies in zebrafish suggest that two genes mapping within the 2q13 critical region (FBLN7 and TMEM87B) could confer susceptibility to congenital heart defects in affected individuals. We reviewed the cardiac characteristics in four patients with 2q13 deletion admitted to our hospitals, and in published patients. Two of our patients had congenital heart defects, consisting in partial anomalous pulmonary venous connection, ostium secundum atrial septal defect ostium secundum, and small muscular ventricular septal defect in one of them, and aortic valve insufficiency with partial fusion of two commissures (incomplete bicuspid aortic valve) and mitral valve insufficiency due to trivial mitral valve prolapse in the other. The anatomic types of CHD in del2q13 syndrome are highly variable and distributed widely, including laterality defects, complex atrioventricular septal defect, septal anomalies, and cardiomyopathies. Cardiac evaluation should be part of the clinical workup at diagnosis of 2q13 deletion.
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Deleción Cromosómica , Cromosomas Humanos Par 2 , Cardiopatías Congénitas/genética , Humanos , RecurrenciaRESUMEN
PURPOSE: Multiple factors influence intrauterine growth and lead to low birth sizes. The impact of genetic alterations on both pre- and post-natal growth is still largely unknown. The aim of this study was to investigate the prevalence of CNVs in an Italian cohort of SGA children with persistent short stature and complex clinical phenotype. rhGH treatment efficacy was evaluated according to the different genotypes. SUBJECTS AND METHODS: Twenty-four SGA children (10F/14M) with persistent short stature associated with dysmorphic features and/or developmental delay underwent CNV evaluation. RESULTS: CNVs were present in 14/24 (58%) SGA children. Six patients had a microdeletion involving the following regions: 3q24q25.1, 8p21.2p12, 15q26, 19q13.11, 20q11.21q12, 22q11.2. In three females, the same microdeletion involving 17p13.3 region was identified. In two different patients, two microduplications involving 10q21.3 and Xp11.3 region were observed. A further female patient showed both an 11q12.1 and an Xq27.1 microduplication, inherited from her mother and from her father, respectively. In a boy, the presence of a 12p13.33 microdeletion and a 19q13.43 microduplication was found. GH treatment efficacy, expressed by height gain and height velocity in the first 12 months of therapy, was similar in subjects with and without CNVs. CONCLUSIONS: These results show that pathogenic CNVs are common in SGA children with short stature associated with additional clinical features. Interestingly, the involvement of 17p13.3 region occurs with a relative high frequency, suggesting that genes located in this region could play a key role in pre- and post-natal growth. rhGH therapy has similar efficacy in the short term whether CNVs are present or not.
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Variaciones en el Número de Copia de ADN , Enanismo , Hormona Liberadora de Hormona del Crecimiento/uso terapéutico , Recién Nacido Pequeño para la Edad Gestacional/crecimiento & desarrollo , Fragmentos de Péptidos/uso terapéutico , Estudios de Cohortes , Enanismo/diagnóstico , Enanismo/tratamiento farmacológico , Enanismo/epidemiología , Enanismo/genética , Femenino , Estudios de Asociación Genética , Edad Gestacional , Humanos , Recién Nacido , Italia/epidemiología , Masculino , Fenotipo , Prevalencia , Estudios Retrospectivos , Resultado del TratamientoAsunto(s)
Pacientes Internos/estadística & datos numéricos , Deficiencia de Magnesio/epidemiología , Magnesio/sangre , Pacientes Ambulatorios/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Hospitales Universitarios , Humanos , Lactante , Recién Nacido , Italia/epidemiología , Deficiencia de Magnesio/sangre , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Desequilibrio Hidroelectrolítico , Adulto JovenRESUMEN
Disorders of calcium metabolism are frequently encountered in routine clinical practice. However limited data are available on the epidemiology of hypocalcemia and hypercalcemia in hospitalized patients. Our aim was to evaluate the frequency of hypocalcemia and hypercalcemia in hospitalized patients. This is a retrospective study based on the laboratory results of all hospitalized subjects (nâ¯=â¯12,334) whose calcemia was determined between January 1st, 2011 and December 31st, 2014. Measurements of serum calcium were carried out by a single centralized laboratory. Hypocalcemia was defined as serum calcium levels <8.2â¯mg/dl and hypercalcemia as serum calcium levels >10.4â¯mg/dl. Albumin correction was applied to adjust serum calcium values. Overall, hypocalcemia accounted for 27.72% (nâ¯=â¯3420) and hypercalcemia for 4.74% (nâ¯=â¯585) of the 12,334 inpatients. The highest prevalence of hypocalcemia was found in patients over 65â¯yr. (nâ¯=â¯2097, 61.31%) vs. younger subjects, while the highest prevalence of hypercalcemia was observed in patients aged 0-18â¯yr. (nâ¯=â¯380, 64.95%). Hypocalcemia was more often encountered in males (nâ¯=â¯1952, 57.07%) while no gender differences were found regarding hypercalcemia. Incidence of hypocalcemia changed over time varying from 35.42% (nâ¯=â¯1061) in 2011 to 21.93% (nâ¯=â¯672) in 2014 (râ¯=â¯-0.98; pâ¯=â¯0.01). Differently, incidence of hypercalcemia did not significantly increase significantly from 3.47% (nâ¯=â¯104) in 2011 to 6.92% (nâ¯=â¯211) in 2014 (râ¯=â¯0.94; pâ¯=â¯0.052). Despite increased awareness about electrolytes disturbance, physicians should consider calcium levels because of life-threatening consequences associated to hypo- and hypercalcemia. Patient's gender and age could be associated to a different risk of calcium disturbance in hospitalized patients.
RESUMEN
Klippel-Trénaunay syndrome (KTS) is described as a complex syndrome characterized by various combinations of capillary, venous, and lymphatic malformations associated with bone and soft tissue hypertrophy. We report a case of a 67-year-old postmenopausal Caucasian women with KTS that shows elevated levels of sclerostin and Dickkopf-related protein 1 (DKK1). Dual-energy X-ray absorptiometry (DXA) BMD T-scores at lumbar spine and femur were normal. Serum calcium and phosphorus levels were consistently normal, 25-hydroxyvitamin D (25OHD) < 30 ng/mL, and normal parathyroid hormone (PTH). Turnover markers (serum osteocalcin [OCN], and carboxy-terminal cross-linking telopeptide of type 1 collagen [CTx]) were in the reference limits. It is interesting to note that the serum levels of sclerostin and DKK-1 were significantly higher in our patient with KTS than in a healthy volunteer (control), without impact on bone mineral density and bone formation markers. In fact, in our patient, the BMD at lumbar spine and femur was normal, and osteocalcin was not suppressed. Based on what is known, we would have expected to find low levels of the inhibitors of the Wnt system, perhaps we can explain the data as a response to the compensation for ß-catenin hyper-transformation.
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Proteínas Morfogenéticas Óseas/sangre , Péptidos y Proteínas de Señalización Intercelular/sangre , Síndrome de Klippel-Trenaunay-Weber/sangre , Absorciometría de Fotón/métodos , Proteínas Adaptadoras Transductoras de Señales , Anciano , Biomarcadores/sangre , Densidad Ósea/fisiología , Remodelación Ósea/fisiología , Femenino , Fémur/fisiopatología , Marcadores Genéticos , Humanos , Síndrome de Klippel-Trenaunay-Weber/fisiopatología , Vértebras Lumbares/fisiopatologíaAsunto(s)
Proteínas Morfogenéticas Óseas/sangre , Diabetes Gestacional/sangre , Péptidos y Proteínas de Señalización Intercelular/sangre , Proteínas Adaptadoras Transductoras de Señales , Adulto , Glucemia/análisis , Femenino , Marcadores Genéticos , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , EmbarazoRESUMEN
We report a case of a woman with a cryptic balanced translocation between chromosomes 5 and 17, suspected during genetic counseling. The woman had a history of previous fetal losses attributed to lissencephaly and intra uterine growth retardation (IUGR) and a daughter with dysmorphic features and mental retardation, previously attributed to a small deletion 5pter, detected years ago by a first generation CGH-array. This peculiar combination of personal and family history suggested the opportunity to carry out a FISH approach, focusing on chromosomes 5 and 17, based on the idea that a malsegregation secondary to a balanced translocation, might have escaped the first CGH array. This approach allowed the identification of a balanced translocation in the mother, FISH in the affected child confirmed the partial 5p deletion predicted by the previous CGH array and identified a new 17p duplication that had not been detected before. The described translocation opens the possibility of alternative imbalances that were probably responsible for previous fetal losses. The imbalances were confirmed by a new high resolution SNP array. We conclude that despite the availability of highly effective and sensitive genomic approaches a careful evaluation of medical history is highly recommended since it can suggest clinical hypothesis that can be confirmed by more classical and molecular cytogenetic based approaches.
RESUMEN
OBJECTIVE: Vitamin D deficiency is widespread and often reported in subjects treated for osteoporosis. Optimal vitamin D repletion was previously shown to maximize the efficacy of anti-resorptive agents. To date, no information exists about the role of vitamin D in the response to strontium ranelate (SrR) treatment. The aim of our study was to investigate the BMD response to SrR in accordance with change of vitamin D status. METHODS: A retrospective analysis of 108 women receiving SrR for postmenopausal osteoporosis was carried out. Women were treated with SrR (2 g/day), with cholecalciferol (25,000 IU biweekly) and calcium carbonate as appropriate. Lumbar spine and femoral neck BMD, bone formation markers (BGP, ALP), resorption marker (OH-PRO) and serum 25(OH)D were measured at baseline after 18-months. All participants were divided into two groups according to the median variation of 25(OH)D over the observation period. RESULTS: SrR was associated with improvement of BMD at lumbar spine (p < 0.0001) and to a non significant variation at femoral neck (p = 0.2). Only subjects with Δ25(OH)D > 6.14 %, reported a significant BMD gain at femoral neck (p = 0.03). Change of BMD at femoral neck was positively associated with modification of ALP (r = 0.28, p = 0.01). This association was not maintained when considering only women with Δ25(OH)D < 6.14 % (r = 0.28, p = 0.09). At a multiple regression analysis, ALP change was the only predictor of femoral neck BMD modification (ß 0.13; SE 0.05; p = 0.01). CONCLUSION: Improvement of vitamin D status was associated with enhancement of BMD response to SrR in women with postmenopausal osteoporosis, in particular, at femoral neck.
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Conservadores de la Densidad Ósea/uso terapéutico , Densidad Ósea/efectos de los fármacos , Osteoporosis Posmenopáusica/sangre , Osteoporosis Posmenopáusica/tratamiento farmacológico , Tiofenos/uso terapéutico , Vitamina D/sangre , Anciano , Densidad Ósea/fisiología , Conservadores de la Densidad Ósea/farmacología , Femenino , Humanos , Persona de Mediana Edad , Osteoporosis Posmenopáusica/diagnóstico , Posmenopausia/efectos de los fármacos , Posmenopausia/fisiología , Estudios Retrospectivos , Tiofenos/farmacologíaRESUMEN
We investigated whether different degrees of hypertension-related cardiovascular involvement are associated with changes in circulating proangiogenic hematopoietic cell (PHC) numbers and/or phenotypes and/or in the PHC redox system in hypertensive individuals with isolated arterial stiffening (AS) hypertensives or with both carotid intima-media thickening and left ventricular hypertrophy (LVH) hypertensives. We also evaluated microRNA (miRs) 221 and 222 (miRs221/222) expression in CD34+ cells, the relationship between these miRs and cell number and reactive oxygen species (ROS) levels, and the expression of manganese superoxide dismutase (MnSOD), catalase (CAT) glutathione peroxidase type-1 (GPx-1) and gp91phox-containing nicotinamide-adenine-dinucleotide-phosphate-oxidase (NOX2). Proangiogenic hematopoietic cells (PHCs) from hypertensive patients and controls were isolated by flow cytometry. PHCs were higher in hypertensives than in controls but were lower in LVH than in AS hypertensives. In CD34+ cells from AS hypertensives, NOX2, MnSOD, CAT and GPx-1 were overexpressed; ROS, miRs and NOX2 were also increased and were associated with cell number. In LVH, we found an imbalance in the cell redox system; MnSOD showed the highest values, whereas CAT and GPx-1 were lower than in AS hypertensives. Intracellular ROS, miRs and NOX2 were higher and inversely associated with cell number. In AS hypertensives, the redox balance may sustain the increase in PHCs; by contrast, in hypertensives with more advanced lesions, redox imbalance may result in increased oxidative stress and cell reduction.
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Células Madre Hematopoyéticas/patología , Hipertensión/patología , Adulto , Biomarcadores/sangre , Enfermedades de las Arterias Carótidas/etiología , Enfermedades de las Arterias Carótidas/patología , Grosor Intima-Media Carotídeo , Estudios Transversales , Enzimas/sangre , Femenino , Células Madre Hematopoyéticas/metabolismo , Humanos , Hipertensión/sangre , Hipertensión/complicaciones , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/etiología , Hipertrofia Ventricular Izquierda/patología , Masculino , MicroARNs/sangre , Oxidación-Reducción , Estrés Oxidativo , Fenotipo , Valor Predictivo de las Pruebas , Análisis de la Onda del Pulso , Factores de Riesgo , Rigidez Vascular , Adulto JovenRESUMEN
OBJECTIVES: To evaluate the association between inflammation, oxidative stress, and circulating progenitor cell (CPC) number and redox equilibrium, vascular lesions and accelerated atherosclerosis in rheumatoid arthritis (RA). METHOD: Circulating CD34+ cells were isolated from 33 RA patients and 33 controls. Reactive oxygen species (ROS) levels and mRNA expression of manganese superoxide dismutase (MnSOD), catalase (CAT), glutathione peroxidase type 1 (GPx-1) antioxidant enzymes, and the gp91phox-containing nicotinamide adenine dinucleotide phosphate (NADPH) oxidase NOX2 were measured in CD34+ cells. C-reactive protein (CRP), fibrinogen, erythrocyte sedimentation rate (ESR), carotid intima-media thickness (cIMT), and arterial stiffness (AS) were also evaluated. We investigated the relationships between inflammatory markers, vascular parameters, cell number, and antioxidant enzymes. RESULTS: CD34+ cell number was lower in RA patients than in controls. In CD34+ cells from RA patients, ROS levels, MnSOD mRNA, and NOX2 mRNA were higher, while mRNA expression of GPx-1 and CAT was significantly lower. The AS, pulse wave velocity (PWV), and augmentation index (AIx) were higher, as was cIMT. CD34+ cell number was inversely correlated with CRP, ROS, PWV, and AIx, and with the CAT/MnSOD and GPx-1/MnSOD ratios. CRP was correlated with MnSOD mRNA, PWV, and AIx but not with CAT and GPx-1 mRNA. CONCLUSIONS: Our data show a link between inflammation, oxidative stress, and the impairment of the antioxidant system of CPCs and their number, and with arterial stiffness in RA subjects. This could suggest a perspective on the accelerated development of vascular damage and atherosclerosis in RA.
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Artritis Reumatoide/epidemiología , Artritis Reumatoide/patología , Aterosclerosis/epidemiología , Aterosclerosis/metabolismo , Inflamación/epidemiología , Estrés Oxidativo , Células Madre/patología , Anciano , Angiografía/métodos , Antígenos CD34/análisis , Antígenos CD34/metabolismo , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/metabolismo , Aterosclerosis/diagnóstico , Velocidad del Flujo Sanguíneo , Proteína C-Reactiva/análisis , Proteína C-Reactiva/metabolismo , Grosor Intima-Media Carotídeo , Estudios de Casos y Controles , Catalasa/análisis , Catalasa/metabolismo , Causalidad , Comorbilidad , Progresión de la Enfermedad , Femenino , Humanos , Inflamación/metabolismo , Inflamación/patología , Mediadores de Inflamación/análisis , Mediadores de Inflamación/metabolismo , Modelos Lineales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Pronóstico , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Índice de Severidad de la Enfermedad , Células Madre/metabolismo , Superóxido Dismutasa/análisis , Superóxido Dismutasa/metabolismo , Ultrasonografía Doppler/métodos , Rigidez Vascular/fisiologíaRESUMEN
A new project was recently initiated for the realization of the "Land Unit and Soil Capability Map of Sardinia" at a scale of 1:50,000 to support land use planning. In this study, we outline the general structure of the project and the methods used in the activities that have been thus far conducted. A GIS approach was used. We used the soil-landscape paradigm for the prediction of soil classes and their spatial distribution or the prediction of soil properties based on landscape features. The work is divided into two main phases. In the first phase, the available digital data on land cover, geology and topography were processed and classified according to their influence on weathering processes and soil properties. The methods used in the interpretation are based on consolidated and generalized knowledge about the influence of geology, topography and land cover on soil properties. The existing soil data (areal and point data) were collected, reviewed, validated and standardized according to international and national guidelines. Point data considered to be usable were input into a specific database created for the project. Using expert interpretation, all digital data were merged to produce a first draft of the Land Unit Map. During the second phase, this map will be implemented with the existing soil data and verified in the field if also needed with new soil data collection, and the final Land Unit Map will be produced. The Land Unit and Soil Capability Map will be produced by classifying the land units using a reference matching table of land capability classes created for this project.
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Bases de Datos Factuales , Sistemas de Información Geográfica , Suelo , Fenómenos Geológicos , ItaliaRESUMEN
BACKGROUND: Several cancer-related genes are silenced by promoter hypermethylation in skin cancers. However, to date the somatic epigenetic events that occur in cutaneous squamous cell carcinoma (SCC) tumorigenesis have not been well defined. OBJECTIVES: To examine epigenetic abnormalities of FOXE1, a gene located on chromosome 9q22, a region frequently lost in SCC. METHODS: We investigated the methylation status of FOXE1 in 60 cases of cutaneous SCC by methylation-specific polymerase chain reaction, and comparatively examined mRNA and protein expression by real-time polymerase chain reaction and Western blot, respectively. RESULTS: We found a higher frequency of FOXE1 promoter hypermethylation in SCCs (55%), as compared with the adjacent uninvolved skin (12%) and blood control samples (9.5%). FOXE1 methylation was frequently seen in association with a complete absence of or downregulated gene expression. Treatment with the demethylating agent 5-Aza-2'-deoxycytidine resulted in profound reactivation of FOXE1 expression. CONCLUSIONS: These results indicate that FOXE1 is a crucial player in development of cutaneous SCC.
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Carcinoma de Células Escamosas/genética , Metilación de ADN , Factores de Transcripción Forkhead/genética , Neoplasias Cutáneas/genética , Anciano , Antimetabolitos Antineoplásicos/uso terapéutico , Azacitidina/análogos & derivados , Azacitidina/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/metabolismo , ADN de Neoplasias/genética , Decitabina , Femenino , Factores de Transcripción Forkhead/biosíntesis , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/biosíntesis , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Neoplásico/genética , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/metabolismoAsunto(s)
Células Endoteliales/patología , Inmunoglobulinas Intravenosas/uso terapéutico , Lupus Eritematoso Sistémico/terapia , Células Madre/patología , Adulto , Células Endoteliales/efectos de los fármacos , Femenino , Movilización de Célula Madre Hematopoyética , Humanos , Masculino , Persona de Mediana Edad , Células Madre/efectos de los fármacosRESUMEN
Despite the efforts made, a serum marker reliable for the screening and follow-up of patients with gastric cancer has not yet been identified. The aim of this preliminary study was to test the role of pro-inflammatory cytokines interleukin 1beta, interleukin 8 and tumour necrosis factor alpha in patients with gastric cancer and in control groups. The statistical analysis of cytokines serum levels in the group with gastric cancer versus control groups has shown considerable differences (p < 0.001) in their mean rates. The results indicate that the cytokines interleukin 1beta, interleukin 8 and tumour necrosis factor alpha might perhaps act as diagnostic markers in patients with gastric cancer. Therefore, it is hypothesized that after more extended trials, their use in the screening and prognostic assessment of these patients could be a possibility.
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Biomarcadores de Tumor/sangre , Interleucina-1/sangre , Interleucina-8/sangre , Neoplasias Gástricas/sangre , Factor de Necrosis Tumoral alfa/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Magnesium sulphate has well known antiplatelet properties. Its effect on leptin-dependent platelet aggregation has not been studied previously. Thus, we performed this ex vivo study to investigate whether magnesium sulphate is able to inhibit leptin-dependent aggregation of human platelets. We obtained platelet rich plasma (PRP) from venous blood samples of 16 healthy male volunteers, and we measured ADP-induced platelet aggregation in the presence of leptin alone (5-500 ng/mL) or leptin and magnesium sulphate (0.25-8 mM). Platelet pre-incubation with leptin led to a significant and dose-dependent increase in ADP-induced platelet aggregation. Magnesium sulphate was able to inhibit the pro-aggregating effect of leptin in a dose-dependent manner. The inhibitory effect was apparent at 1 mM of magnesium sulphate concentration (% maximal aggregation=38.1 +/- 12.2) and reached its maximum at 8 mM (% maximal aggregation=20.0 +/- 7.8). Our results demonstrate that leptin-dependent platelet aggregation is inhibited by magnesium sulphate in a dose-dependent manner. It seems conceivable that the blocking of hydrolysis of phosphoinositide and of intracellular calcium mobilization by magnesium sulphate may be involved in these findings.
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Leptina/fisiología , Sulfato de Magnesio/farmacología , Agregación Plaquetaria/efectos de los fármacos , Adenosina Difosfato/farmacología , Adulto , Humanos , MasculinoRESUMEN
OBJECTIVE: To investigate the effects of leptin on platelet aggregation and platelet free calcium (Ca(2+)) concentrations, and the role of the long form of leptin receptor (ObRb) and the phospholipase C (PLC) in mediating leptin effects on platelet function. DESIGN: Cross-sectional, clinical study. SETTING: Outpatient's Service for Prevention and Treatment of Obesity at the University Hospital of Messina, Italy. SUBJECTS: A total of 19 healthy, 14 overweight, and 16 obese male subjects. MEASUREMENTS: ADP-induced platelet aggregation and platelet Ca(2+) were measured after incubation of platelet-rich plasma with leptin alone 5-200 ng/ml, leptin 200 ng/ml and anti-human leptin receptor long-form antibody (ObRb-Ab) 5-10 microl, or leptin 200 ng/ml and PLC inhibitor U73122 0.5-1 nmol/l. RESULTS: Platelet stimulation with leptin lead to a significant and dose-dependent increase in platelet aggregation in healthy subjects. This effect was blunted in overweight, and strongly reduced in obese subjects. Similarly, the incubation with leptin induced a significant and dose-dependent increase in platelet free calcium, which was blunted in overweight and obese patients. The effect of leptin on platelet aggregation and platelet Ca(2+) was completely abated by the anti-ObRb-Ab and the PLC inhibitor U73122. CONCLUSIONS: Leptin produces a dose-dependent enhancement of ADP-induced platelet aggregation in humans. Platelet aggregation response to leptin is blunted, but not completely abolished in overweight/obese subjects, thus suggesting that platelet may represent a site of leptin resistance in human obesity. Leptin increases platelet free calcium in a dose-dependent manner. The inhibition of PLC completely abates the effect of leptin on both platelet aggregation and Ca(2+) levels. These findings suggest that signaling pathway other than JAK-STAT tyrosine phosphorylation (ie PLC and calcium) may be involved in mediating the prothrombotic action of leptin.
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Plaquetas/efectos de los fármacos , Leptina/farmacología , Obesidad/sangre , Agregación Plaquetaria/efectos de los fármacos , Adenosina Difosfato/sangre , Adulto , Plaquetas/metabolismo , Índice de Masa Corporal , Calcio/sangre , Estudios Transversales , Humanos , Masculino , Receptores de Superficie Celular/fisiología , Receptores de Leptina , Fosfolipasas de Tipo C/fisiologíaRESUMEN
"Band 3," an integral membrane protein of red blood cells, plays a relevant role in anionic transport. The C- and N-terminal portions of band 3 are cytoplasmatics, and the last is the link site for different glycolitic enzymes, such as glyceraldehyde-3-phosphate dehydrogenase, aldolase, phosphofructokinase, and hemoglobin. All or some of these interactions on the CDB3 protein could allow a subtle modulation of anion flux. The interaction among HbA, Mg(2+), and membrane proteins has been sufficiently investigated, but not the effect of Mg(2+) on pathological hemoglobin in relation to the influx of the SO(4)(2-). The aim of this study was to evaluate the involvement of hemoglobin S in sulfate transport. This has been measured with native and increased concentrations of Mg(2+), using normal erythrocytes containing HbA, sickle red cells containing HbS, or ghosts obtained from both erythrocytes and normal erythrocytes ghosts with HbS added. The magnitude of the SO(4)(2-) rate constant measured in normal red blood cells increased markedly when measured in the presence of varied Mg(2+) concentrations. The results show that a low increase of intracellular Mg(2+) concentrations exercises a different HbA modulation on band 3 protein and consequently higher anion transport activity. The same experiments carried out in sickle red cells showed that the SO(4)(2-) rate constant measured in the presence of native concentrations of Mg(2+) was normal, compared to normal red cells, and was not affected by any increase of intracellular Mg(2+). Our suppositions with regard to the importance exercised by the hemoglobin and the Mg(2+) on the SO(4)(2-) influx were confirmed by comparison of the data obtained through measuring SO(4)(2-) influx with native and increased concentrations of Mg(2+) in both normal and sickle red cell ghosts. Both revealed the same sensitivity to Mg(2+) due to withdrawal of hemoglobins. The incorporation of HbS in normal as well as in sickle red cell ghosts reduced the Mg(2+) response to sulfate influx in both the reconstituted ghosts. Our research demonstrated that the different effects exercised on the rate constants of SO(4)(2-) influx in normal (HbA) and sickle red cells (HbS) by the increased intracellular Mg(2+) could be ascribed to the physical-chemical influence exercised either on the hemoglobins or on the intracellular contents of erythrocytes.