RESUMO
La osteoporosis y las enfermedades cardiovasculares son patologías prevalentes en mujeres posmenopáusicas. La calcificación vascular es un proceso en el que se produce una distorsión de la arquitectura natural del tejido arterial con una transformación símil osteogénica. La fisiología vascular y la osteogénesis (formación y remodelación ósea) comparten una complejidad metabólica y funcional crítica, que ha sido poco explorada en forma conjunta, lo que ha impulsado la concepción del Eje Óseo-Vascular como nueva área de investigación, con una visión de estudio integradora con la finalidad de identificar vínculos entre ambos sistemas. En virtud de la controversia planteada sobre los riesgos/beneficios de la terapia de reemplazo hormonal para prevenir enfermedades asociadas a la menopausia, se ha incentivado la búsqueda de nuevas opciones de tratamiento. Los fitoestrógenos, como compuestos nutracéuticos, surgen como una potencial alternativa terapéutica. En particular, las isoflavonas presentan gran analogía estructural con el estrógeno humano 17ß-estradiol, lo que les permite unirse al receptor de estrógenos e inducir acciones estrogénicas tanto en células animales como humanas. Basado en la experiencia propia como en lo reportado en la bibliografía, este artículo analiza la información disponible sobre las acciones vasculares y óseas de los fitoestrógenos (específicamente la isoflavona genisteína), con una visión de ciencia traslacional. Es de esperar que los avances en el conocimiento derivado de la ciencia básica, en un futuro cercano, pueda contribuir a decisiones clínicas a favor de promover terapias naturales de potencial acción dual, para la prevención de enfermedades de alta prevalencia y significativo costo social y económico para la población. (AU)
Osteoporosis and cardiovascular diseases are prevalent diseases in postmenopausal women. Vascular calcification is a cellmediated process that leads to the loss of the natural architecture of the arterial vessels due to osteogenic transdifferentiation of smooth muscle cells, and matrix mineralization. Vascular physiology and osteogenesis (bone formation and remodeling) share a critical metabolic and functional complexity. Given the emerging integrative nature of the bonevascular axis, links between both systems are a matter of ongoing interest. In view of the controversy stated about the risks/benefits of hormone replacement therapy to prevent diseases associated with menopause, phytoestrogens arise as a potential natural therapeutic alternative. In particular, isoflavones have a strong structural analogy with the human estrogen 17ß-estradiol, that allows them to bind to the estrogen receptor and induce estrogenic actions in animal and human cells. Based in on our own experience and the information available in the literature, in this paper we provide an overview of the role of phytoestrogens on vascular and bone tissues, with focus on Genistein actions. We wish that the basic knowledge acquired may contribute to guide clinical decisions for the promotion of natural therapies for the treatment of diseases that conspire against human health. (AU)
Assuntos
Humanos , Masculino , Feminino , Osteogênese/efeitos dos fármacos , Fitoestrógenos/uso terapêutico , Aterosclerose/tratamento farmacológico , Calcificação Vascular/tratamento farmacológico , Osteogênese/fisiologia , Menopausa , Doenças Cardiovasculares/complicações , Osteoporose Pós-Menopausa , Remodelação Óssea , Genisteína/uso terapêutico , Fitoestrógenos/classificação , Fitoestrógenos/farmacologia , Aterosclerose/fisiopatologia , Estrogênios/biossíntese , Calcificação Vascular/fisiopatologia , Calcificação Vascular/metabolismoRESUMO
Phytoestrogens have been proposed as a natural therapy for prevention of bone loss. In this work, we studied the mechanism of action of genistein on osteoblast differentiation. Primary cell cultures of calvarial osteoblasts isolated from female Wistar rats were in vitro exposed to genistein. Osteoblast differentiation markers were measured. Genistein stimulated osteoblast migration (71-257% above control). An earlier upregulation of estrogen receptor alpha gene expression and an enhancement of mRNA levels of the Runt-related transcription factor 2 were detected after 3 days of culture. The isoflavone significantly increased osteocalcin expression, extracellular collagen deposition, and alkaline phosphatase activity. The mechanism displayed by genistein involved estrogen receptor and nitric oxide pathway participation, since cell preincubation with the estrogen receptor antagonist ICI 182780, or the nitric oxide synthase inhibitor L-NAME, suppressed the phytoestrogen action. Evidence of MAPK and PI3K transduction systems participation on the stimulatory action of genistein on extracellular collagen deposition and alkaline phosphatase activity was also obtained. Genistein favored monocyte adhesion to osteoblasts (77% above control) in an ER; NOS; and MAPK kinase-dependent and PI3K-dependent manner. Co-cultured osteoblast-monocyte long term exposed (21 days) to genistein exhibited a high number of multinucleated and tartrate-resistant acid phosphatase-positive cells added to osteoblasts, suggesting that the phytoestrogen promotes osteoclast differentiation. In conclusion, genistein promoted osteoblastogenesis through the participation of ER and NOS pathways, and the contribution of ERK or PI3K signal transduction pathways, and also stimulates osteoclast differentiation from its mononuclear progenitor.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Genisteína/farmacologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Fitoestrógenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Células Cultivadas , Feminino , Óxido Nítrico/metabolismo , Osteoblastos/citologia , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Cultura Primária de Células , Ratos , Ratos Wistar , Receptores de Estrogênio/metabolismo , Crânio/citologiaRESUMO
Although estradiol bone contribution has been deeply studied, little is known about the action of estrone. We investigated the direct action of estrone on osteoblasts growth and differentiation, with focus on the biochemical mechanism displayed by the estrogen. Murine calvarial osteoblast cultures in vitro exposed to 10â¯nM estrone were employed. Estrone enhanced gene expression of the osteogenic differentiation marker, Runx2 mRNA (150% above control). The hormone significantly increased cell proliferation (38% above control), nitric oxide production (108% above control), alkaline phosphatase activity (50% above control), in addition to stimulation of extracellular matrix mineralization. Using specific antagonists, we found that the mechanism of action of estrone involves estrogen receptor, nitric oxide synthase and MAPK signalling pathways participation. The hormone acts by its own and probably not via conversion to estradiol, since 17â¯B HSD inhibition did not affect the hormonal action. This work shows a novel action of estrone on bone cells promoting osteoblastogenesis.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Estrogênios/farmacologia , Estrona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Osteoblastos/citologia , Osteogênese/efeitos dos fármacos , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Óxido Nítrico/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Ratos , Ratos Wistar , Transdução de SinaisRESUMO
Sickle cell syndrome HbS/ß thalassemia is an inheritable mendelian type disease where two affected alleles are simultaneously present, one from HbS (ßS) and the other from ß thalassemia. That situation is mainly linked to individuals who share African and Mediterranean ancestors. The mutation responsible for HbS is a point mutation, whereas for ß thalassemia, there are more than 200 mutations that cause different degrees of deficiency synthesis of ß globin chain, which justifies the clinical and genetic heterogeneity of this syndrome. It is presented a clinical case of a young adult man with limited resources that consulted by longstanding bone pain. The patient presented anemia with a marked microcytosis. Hemoglobin electrophoresis was performed, an abnormal peak in position of HbS and high HbA2 fraction were detected. These last results indicated two possible molecular alterations simultaneously, for this reason the molecular study was performed looking for the most common ß thalassemia mutations in our population and, the point mutation responsible for S hemoglobinopathy. Clinical data and biochemical laboratory allowed the diagnosis of sickle cell syndrome. The molecular study confirmed the syndrome carrying mutations IVS-I nt 110 G > A, responsible for ß thalassemia and, codon 6 A > T (GAG â GTG: Glu â Val) responsible for S hemoglobinophaty. Since it is a disease of high health impact, it is important to provide genetic counseling to the whole family.
Assuntos
Anemia Falciforme/genética , Hemoglobina Falciforme/genética , Mutação Puntual , Talassemia beta/genética , Adulto , Anemia Falciforme/diagnóstico , Biomarcadores , Eletroforese Capilar , Humanos , Masculino , Biologia Molecular , Reação em Cadeia da Polimerase , Síndrome , Talassemia beta/diagnósticoRESUMO
El síndrome drepanocítico HbS/β talasemia responde a la herencia de tipo mendeliana en simultáneo de un alelo βs de la hemoglobina S (HbS) y un alelo de β talasemia. Vinculado fundamentalmente a individuos que comparten ascendencia africana y de países del Mediterráneo. La mutación responsable de la HbS es puntual, mientras que para la β talasemia existen más de 200 mutaciones que causan diferentes grados de deficiencia de síntesis de la cadena de β globina, lo cual justifica la heterogeneidad clínica y genética de este síndrome. Se presenta el caso clínico de un adulto joven de escasos recursos que consulta por dolores óseos de larga data. Registra hemogramas con anemia y marcada microcitosis. Se le realizó electroforesis de Hb detectándose un pico anómalo en posición de HbS y elevada fracción de HbA2. El resultado de la electroforesis de hemoglobina indica dos posibles alteraciones moleculares en simultáneo, por tal motivo se realizó el estudio molecular de las mutaciones más frecuentes en nuestra población de β talasemia y de la mutación puntual responsable de la hemoglobinopatía S. A partir de la clínica y datos del laboratorio bioquímico se diagnosticó el síndrome drepanocítico y se confirmó por biología molecular la portación de las mutaciones IVS-Int 110 G > A (β talasemia) y del codón 6 A > T (GAG→GTG: Glu→Val) responsable de la hemoglobinopatía S. Dado que es una enfermedad de alto impacto sanitario, es importante un adecuado asesoramiento genético a toda la familia.
Sickle cell syndrome HbS/β thalassemia is an inheritable mendelian type disease where two affected alleles are simultaneously present, one from HbS (βS) and the other from β thalassemia. That situation is mainly linked to individuals who share African and Mediterranean ancestors. The mutation responsible for HbS is a point mutation, whereas for β thalassemia, there are more than 200 mutations that cause different degrees of deficiency synthesis of β globin chain, which justifies the clinical and genetic heterogeneity of this syndrome. It is presented a clinical case of a young adult man with limited resources that consulted by longstanding bone pain. The patient presented anemia with a marked microcytosis. Hemoglobin electrophoresis was performed, an abnormal peak in position of HbS and high HbA2 fraction were detected. These last results indicated two possible molecular alterations simultaneously, for this reason the molecular study was performed looking for the most common β thalassemia mutations in our population and, the point mutation responsible for S hemoglobinopathy. Clinical data and biochemical laboratory allowed the diagnosis of sickle cell syndrome. The molecular study confirmed the syndrome carrying mutations IVS-I nt 110 G > A, responsible for β thalassemia and, codon 6 A > T (GAG → GTG: Glu → Val) responsible for S hemoglobinophaty. Since it is a disease of high health impact, it is important to provide genetic counseling to the whole family.
Assuntos
Humanos , Masculino , Adulto , Hemoglobina Falciforme/genética , Mutação Puntual , Talassemia beta/genética , Anemia Falciforme/genética , Síndrome , Biomarcadores , Reação em Cadeia da Polimerase , Talassemia beta/diagnóstico , Eletroforese Capilar , Anemia Falciforme/diagnóstico , Biologia MolecularRESUMO
In this work we provide evidence that estrone "per se" modulates cellular endothelial growth and survival, events that play key roles in the development of vascular disease. Moreover, under oxidative stress conditions the hormone prevented apoptosis triggered by hydrogen peroxide. Although estrone did not affect E-selectin and VCAM-1 mRNAs synthesis, the hormone prevented the expression of these adhesion molecules induced by the proinflammatory agent LPS. The steroid partially attenuated leukocyte adhesion not only under basal conditions but also in the presence of LPS. Using ICI182780 compound as estrogen receptor antagonist, and PD98059 as MAPK inhibitor we obtained evidence that the mitogenic action of estrone involved the participation of ER and MAPK transduction pathway activation. The presence of estradiol impaired the effect of estrone on cell proliferation and vasoactive production. These results suggest that estrone exhibits a remarkable biological action on endothelial cells, modulating vasoactive production, proliferation, apoptosis, and cell adhesion events.
Assuntos
Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Estrona/farmacologia , 17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Animais , Aorta/citologia , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Fragmentação do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Selectina E/metabolismo , Células Endoteliais/fisiologia , Endotélio Vascular/fisiologia , Equilina/farmacologia , Estradiol/farmacologia , Feminino , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/fisiologia , Óxido Nítrico/metabolismo , Ratos , Ratos Wistar , Timidina/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismoRESUMO
The aim of the present study was to investigate the direct action of the phyto-oestrogen genistein (Gen) on vascular endothelial behaviour, either in the presence or absence of proinflammatory agents. In rat aortic endothelial cell (EC) cultures, 24 h of treatment with Gen significantly increased cell proliferation in a wide range of concentration (0.001-10 nm). This mitogenic action was prevented by the oestrogen receptor (ER) antagonist ICI 182780 or by the presence of the specific NO synthase inhibitor l-nitro-arginine methyl ester. When monocytes adhesion to EC was measured, Gen partially attenuated leucocyte adhesion not only under basal conditions, but also in the presence of bacterial lipopolysaccharides (LPS). The effect of the phyto-oestrogen on the expression of EC adhesion molecules was evaluated. Gen down-regulated the enhancement in mRNA levels of E-selectin, vascular cell adhesion molecule-1 and P-selectin elicited by the proinflammatory agent bacterial LPS. The regulation of EC programmed death induced by the isoflavone was also demonstrated. Incubation with 10 nm Gen prevented DNA fragmentation induced by the apoptosis inductor H2O2. The results presented suggest that Gen would exert a protective effect on vascular endothelium, due to its regulatory action on endothelial proliferation, apoptosis and leucocyte adhesion, events that play a critical role in vascular diseases. The molecular mechanism displayed by the phyto-oestrogen involved the participation of the ER and the activation of the NO pathway.
Assuntos
Células Endoteliais/efeitos dos fármacos , Genisteína/farmacologia , Glycine max/química , Animais , Aorta Torácica , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/citologia , Feminino , Genisteína/química , Ratos , Ratos WistarRESUMO
Se evaluó al receptor de transferrina (RsT) como marcador de hierro funcional en dos grupos: 1) controles (50 adultos sanos de ambos sexos residentes a nivel del mar); 2) 50 anémicos ferroprivos por alteraciones nutricionales, gastrointestinales o ginecológicas (AFP). El valor medio en los controles fue 16.6 nmol/l (8.8 a 26.2 nmol/l), sin diferencias significativas por edad y sexo. En el grupo AFP, el valor medio fue 66.3 nmol/l (16.1 a 148.4 nmol/l). El análisis estadístico (características del operador receptor, ROC) estableció un intervalo de referencia óptimo de 8.8 a 25.8 nmol/l, Los valores predictivos, positivo (VPP) y negativo (VPN), del RsT como prueba diagnóstica fueron 97.5 y 97.7 por ciento, respectivamente, y la eficiencia diagnóstica (ED) fue 97.7 por ciento. Tanto en los controles como en los AFP se observó: 1) concentraciones inversas entre el RsT y la ferritina (F) (tendencia potencial entre las variables (p<0.001) con un coeficiente de determinación del 72 por ciento); 2) ampilas variaciones del RsT para concentraciones de hemoglobina (Hb) inferiores a 100 g/l (tendencia exponencial (p < 0.001) con un coeficiente de determinación del 71 por ciento); 3) valores de la relación RsT/log ferritina (índice RsT/F) sensiblemente mayores en AFP (75.8) que en los controles (9.6). La administración de hierro normalizó los niveles del RsT en pacientes ferroprivos, sin cambiar significativamente las concentraciones de ferritina sérica. Nuestros estudios demuestran que el RsT mide con alta especificidad y sensibilidad el hierro funcional. (AU)
Assuntos
Adulto , Adolescente , Idoso , Pessoa de Meia-Idade , Humanos , Feminino , Anemia Ferropriva/diagnóstico , Receptores da Transferrina/sangue , Sensibilidade e Especificidade , Ensaio de Imunoadsorção Enzimática , Hemoglobinas/análise , Ferritinas/sangue , Ferro/uso terapêutico , Anemia Ferropriva/tratamento farmacológicoRESUMO
Se evaluó al receptor de transferrina (RsT) como marcador de hierro funcional en dos grupos: 1) controles (50 adultos sanos de ambos sexos residentes a nivel del mar); 2) 50 anémicos ferroprivos por alteraciones nutricionales, gastrointestinales o ginecológicas (AFP). El valor medio en los controles fue 16.6 nmol/l (8.8 a 26.2 nmol/l), sin diferencias significativas por edad y sexo. En el grupo AFP, el valor medio fue 66.3 nmol/l (16.1 a 148.4 nmol/l). El análisis estadístico (características del operador receptor, ROC) estableció un intervalo de referencia óptimo de 8.8 a 25.8 nmol/l, Los valores predictivos, positivo (VPP) y negativo (VPN), del RsT como prueba diagnóstica fueron 97.5 y 97.7 por ciento, respectivamente, y la eficiencia diagnóstica (ED) fue 97.7 por ciento. Tanto en los controles como en los AFP se observó: 1) concentraciones inversas entre el RsT y la ferritina (F) (tendencia potencial entre las variables (p<0.001) con un coeficiente de determinación del 72 por ciento); 2) ampilas variaciones del RsT para concentraciones de hemoglobina (Hb) inferiores a 100 g/l (tendencia exponencial (p < 0.001) con un coeficiente de determinación del 71 por ciento); 3) valores de la relación RsT/log ferritina (índice RsT/F) sensiblemente mayores en AFP (75.8) que en los controles (9.6). La administración de hierro normalizó los niveles del RsT en pacientes ferroprivos, sin cambiar significativamente las concentraciones de ferritina sérica. Nuestros estudios demuestran que el RsT mide con alta especificidad y sensibilidad el hierro funcional.