Canales de calcio como blanco de interés farmacológico / Calcium channels as a pharmacological target

Resumen Los canales de calcio son proteínas de membrana que constituyen la vía más importante para el ingreso del ion calcio (Ca2+) a la célula. Al abrirse, permiten el ingreso selectivo del ion, iniciando una variedad de procesos como contracción muscular, secreción endocrina y liberación de neurotransmisores, entre otros. Estas proteínas se agrupan en tres categorías de acuerdo con sus propiedades estructurales y funcionales: (i) Canales de Ca2+ operados por interacción receptor-ligando (ROCC), (ii) Canales activados por parámetros físicos (Transient Receptor Potencial, TRP) y (iii) Canales de Calcio dependientes de voltaje (VDCCs), siendo estos últimos los más estudiados debido a su presencia en células excitables. Dada la importancia de Ca2+ en la fisiología celular, los canales de Ca2+ constituyen un punto de acción farmacológica importante para múltiples tratamientos y, por tanto, son objeto de estudio para el desarrollo de nuevos fármacos. El objetivo de esta revisión es explicar la importancia de los canales de Ca2+ desde una proyección farmacológica, a partir de la exploración documental de artículos publicados hasta la fecha teniendo en cuenta temas relacionados con la estructura de los canales Ca2+, sus propiedades biofísicas, localización celular, funcionamiento y su interacción farmacológica.

Abstract Calcium channels are membrane proteins that constitute the most important route for the entry of the calcium ion (Ca2+) into the cell. When opened, they allow selective ion entrance, starting a variety of processes such as muscular contraction, endocrine secretion and neurotransmitters release, among others. These proteins are classified in three categories according to their structural and functional properties: (i) Receptor-operated calcium channels (ROCC), (ii) Channels activated by physical parameters (Transient Receptor Potential or TRP-channels) and (iii) Voltage-dependent calcium channels (VDCCs), the latter being the most studied due to its presence in excitable cells. Given the importance of Ca2+ in the cellular physiology, the calcium channels constitute targets for pharmacological action for multiple treatments, and therefore, they are object of study for the development of new medicaments. The objective of this review is to explain the importance of the channels of Ca2+ from a pharmacological projection, by exploring the articles published, bearing in mind topics related to the structure of the channels Ca2+, properties of their biophysics, cellular location, functioning and their pharmacological interaction.

Cambios morfofisiológicos celulares durante la reanimación cardiopulmocerebral / Morph-physiological cellular changes during cardiac-pulmonary-cerebral resuscitation

Las células realizan transformaciones estructurales y metabólicas ante situaciones de estrés, lo que les permite mantener una adecuada homeostasis y evitar la muerte. La presente revisión bibliográfica tuvo como objetivo describir los principales cambios morfofisiológicos celulares que acontecen en la parada cardiaca y reanimación cardiopulmocerebral. El método incluyó una revisión documental (bases de datos SciELO Regional, PubMed, Cochrane e Infomed), realizada durante el primer semestre del 2018. Fueron seleccionadas 28 referencias. Se concluye que existen cambios celulares durante el cese circulatorio, las maniobras de resucitación y en la reperfusión. En la parada cardiaca, los cambios celulares se expresan en todos los organelos y puede llevar a muerte por necrosis. Durante la reperfusión se producen nuevos cambios estructurales, por entrada de calcio, alteraciones en sodio, producción de radicales libres e inflamación. Los cambios morfofisiológicos dependerán del estado metabólico previo, el tiempo de parada cardiaca y la instauración eficaz de medidas de resucitación.

Cell suffer structural and metabolic changes in stress situations,which allow them to maintain an adequate homeostasis and avoid death . This bibliographic review had the objective of describing the main morph-physiological changes which occur in cardiac failure and cardiac-pulmonary-cerebral resuscitation. The method was documentary reviewing (database Regional SciELO, PubMed, Cochrane and Infomed), developed during the first semester of 2018. Twenty eight references were selected. It was concluded that there are cellular changes during circulatory stop, the procedures of resuscitation and re-perfusion. In cardiac failure, cellular changes are expressed in all the organelles. And may cause death due to necroses. During re-perfusion new structural changes occur, for calcium entrance, sodium disturbances, production of free radicals and swelling. Morph.physiological changes depend on previous metabolic condition, time of cardiac failure and the successful establishment of resuscitation measures.

The role of under-investigated connexins in musculoskeletal tissue: a brief review with emphasis on bone tissue / El papel de las escasamente investigadas conexinas en el tejido músculo-esquelético: una breve revisión con énfasis en el tejido óseo

Connexins (Cxs) are a family of transmembrane proteins that form gap junctions and hemi-channels, which mediate cell-cell communication between neighboring cells and the respective extracellular milieu in different tissues. Most tissues and cell types throughout the body express one or more Cx proteins, highlighting its importance in regulating cell growth, differentiation, adhesion, migration, cell death and others. Moreover, Cx can propagate intracellular signals through its C-terminus domain, and thus function beyond a mere channel. Cx43 is the most highly expressed and most well studied Cx in bone and musculoskeletal tissues, although Cx40, Cx45, Cx46 and more recently, the Cx37 have been described in bone tissue, along with Cx26, Cx32 and Cx39 in other musculoskeletal tissues. Here, we discuss the basic structure of gap junctions and the role of the Cxs in musculoskeletal tissue, with special focus on Cx37. (AU)

Las conexinas (Cxs) son una familia de proteínas transmembrana que forman uniones en hendidura y hemicanales encargados de mediar la comunicación entre células vecinas y el respectivo medio extracelular en diferentes tejidos. La mayoría de los tejidos y células expresan una o más proteínas conexina, jugando un papel importante en la regulación de la proliferación celular, diferenciación, adhesión, migración y muerte celular, entre otras funciones. Además de actuar como un canal, las conexinas pueden propagar señales intracelulares a través del dominio C-terminal. La Cx43 es la conexina mas expresada y mejor estudiada en el tejido óseo y el músculo, aunque las Cx40, Cx45, Cx46, y mas recientemente Cx37, son también detectadas en el hueso. A su vez la expresión de la Cx26, Cx32 y Cx39 ha sido observada en otros tejidos músculoesqueléticos. En este manuscrito describimos la estructura básica de las uniones tipo gap y el papel que las Cxs, y en especial la Cx37, tienen en tejidos músculo-esqueléticos. (AU)

Simultaneously expressed miR-424 and miR-381 synergistically suppress the proliferation and survival of renal cancer cells---Cdc2 activity is up-regulated by targeting WEE1

OBJECTIVES: MiRNAs are intrinsic RNAs that interfere with protein translation. Few studies on the synergistic effects of miRNAs have been reported. Both miR-424 and miR-381 have been individually reported to be involved in carcinogenesis. They share a common putative target, WEE1, which is described as an inhibitor of G2/M progression. Here, we studied the synergistic effects of miR-424 and miR-381 on renal cancer cells. METHODS: The viability of 786-O cells was analyzed after transfection with either a combination of miR-424 and miR-381 or each miRNA alone. We investigated cell cycle progression and apoptosis with flow cytometry. To confirm apoptosis and the abrogation of G2/M arrest, we determined the level of pHH3, which is an indicator of mitosis, and caspase-3/7 activity. The expression levels of WEE1, Cdc25, γH2AX, and Cdc2 were manipulated to investigate the roles of these proteins in the miRNA-induced anti-tumor effects. To verify that WEE1 was a direct target of both miR-424 and miR-381, we performed a dual luciferase reporter assay. RESULTS: We showed that the combination of these miRNAs synergistically inhibited proliferation, abrogated G2/M arrest, and induced apoptosis. This combination led to Cdc2 activation through WEE1 inhibition. This regulation was more effective when cells were treated with both miRNAs than with either miRNA alone, indicating synergy between these miRNAs. WEE1 was verified to be a direct target of each miRNA according to the luciferase reporter assay. CONCLUSIONS: These data clearly demonstrate that these two miRNAs might synergistically act as novel modulators of tumorigenesis by down-regulating WEE1 expression in renal cell cancer cells. .

Pseudobrânquia do guaru Poecilia reticulata (Peter, 1859): análise estrutural, morfométrica e histoquímica para detecção de glicoconjugados / Pseudo-gill of guppy, Poecilia reticulata (Peter, 1859): structural, morphometric, and histochemical analyses for the detection of glycoconjugates

A morfologia, os parâmetros citomorfométricos e os glicoconjugados presentes na pseudobrânquia de guaru, Poecilia reticulata Peter, 1859 (Cyprinodontiformes: Poeciliidae), foram investigados por microscopia de luz acoplada ao sistema de captura e análise de imagens, juntamente por histoquímica com lectinas. A anatomia microscópica indicou que P. reticulata possui pseudobrânquia glandular formada por dois lóbulos, a qual se localiza abaixo do epitélio faringiano. O órgão é constituído por parênquima vascularizado e rico em células pseudobranquiais. Esse tipo celular exibe estado citofisiológico ativo, com abundante sistema de biomembranas e ausência de óstio na superfície apical,que por sua vez é encontrado nas células ricas em mitocôndrias das holobrânquias. Assim, indica-se que as células da pseudobrânquia se distinguem das células das holobrânquias em relação à morfologia, histoquímica e fisiologia. Em decorrência dessas características intrínsecas, a pseudobrânquia de alevinos do guaru pode desempenhar funções não respiratórias nas fases iniciais do desenvolvimento. Além disso, a caracterização da pseudobrânquia do guaru possibilitará estudos futuros sobre o efeito de poluentes aquáticos em espécies biomonitoras, como P. reticulata.

The morphology, cytomorphometric parameters, and glycoconjugates present in the pseudo-gill of guppy, Poecilia reticulata Peter, 1859 (Cyprinodontiformes: Poeciliidae), were investigated by light microscopy coupled to image capture and analysis system, and also by lectin histochemistry. The microscopic anatomy indicates that P. reticulata has a glandular pseudo-gill formed by two lobes, located underneath the pharynx epithelium. The organ is formed by vascularized parenchyma rich in pseudo-gill cells. This cell type exhibits active cytophysiological state with an abundant system of biomembranes and lacking of ostium in apical surface, which in turn is found in the mitochondria-rich cells of the holobranch. This indicates that the pseudo-gill cells distinguishe from the holobranch cells in their morphology, histochemistry and physiology. Due to these intrinsic characteristics, the pseudo-gill of guppy fingerlings may have non-respiratory function in the initial phase of their development. The characterization of guppy's pseudo-gill could facilitate further studies about the effect of water pollutants on biomonitor species, such as P. reticulata.

Mecanismos moleculares da ação tóxica pró-oxidante de 1,4-diamino-2-butanona, um análogo de putrescina, sobre células de mamíferos e Trypanosoma cruzi / The Molecular mechanisms of pro-oxidant activity of 1,4-diamino-2-butanone, a putrescine analogue, to mammalian cells and Trypanosoma cruzi

Compostos α-aminocarbonilícos como ácido 5-aminolevulínico (ALA) e aminoacetona (AA) apresentam um grande potencial pró-oxidante, pois sofrem reações de enolização e subseqüente oxidação aeróbica, com a formação de espécies radicalares de oxigênio, íons NH4+ e α-oxoaldeídos potencialmente citotóxicos. A α-aminocetona 1,4-diamino-2-butanona (DAB), um análogo da putrescina, é um agente microbicida de vários parasitas incluindo Trypanosoma cruzi. Acredita-se que o mecanismo de morte desencadeado por DAB nos parasitas seja por meio da inibição competitiva da ornitina descarboxilase (ODC), importante enzima do metabolismo de poliaminas, muito embora tenha sido observado de igual forma danos oxidativos nestes parasitas quando tratados com DAB. O objetivo deste trabalho é esclarecer o mecanismo de oxidação química de DAB e sua ação pró-oxidante à cultura de células de mamíferos (LLC-MK2 e RKO), assim como sua atividade microbicida contra tripomastigotas de Trypanosoma cruzi. Demonstramos aqui que DAB, quimicamente similar ao ALA e AA, sofre reação de oxidação catalisada por íons fosfato, e por íons de metais de transição como Fe(II) e Cu(II), resultando na formação de radicais de oxigênio, H2O2, NH4+, 2-oxo-4-aminobutanal como produto principal da oxidação de DAB e de compostos ciclicos de caracter pirrólico. Danos oxidativos observados em ferritina, apotransferrina e liposomos de cardiolipina e fosfatidilcolina (20:80) contribuem para a nossa hipótese de ação pró-oxidante de DAB. O tratamento de células de mamíferos das linhagens LLC-MK2 (IC50 1,5 mM, tratamento de 24 h) e RKO (IC50 0,3 mM, tratamento de 24 h) com DAB levou à alteração do balanço redox celular, à ativação de resposta antioxidante e ao desencadeamento de morte celular via apoptose e parada de ciclo celular. Em culturas de tripomastigotas de T. cruzi o tratamento com DAB culminou na redução da motilitidade e viabilidade destes parasitas (IC50 0,2 mM, tratamento de 4 h), assim como depleção do...

α-Aminocarbonyl componds such as 5-aminolevunilic acid (ALA) and aminoacetone (AA) have been shown to exhibit pro-oxidant properties. These compounds undergo phosphate-catalyzed enolization in physiological pH and subsequent aerobic oxidation, yielding reactive oxygen species, NH4+ ions and an α-oxoaldehyde highly cytotoxic. The α-aminoketone 1,4-diamino-2-butanone (DAB) is a putrescine analogue and a microbicidal agent to various parasites including Trypanosoma cruzi. The mechanism of DAB toxicity to these parasites is attributed to DAB competitive inhibition of ornithine decarboxylase (ODC), a key enzyme on polyamine biosynthesis, although it has also been shown DAB isto implicated in oxidative damage to these parasites. Our aim is to clarify the mechanism of DAB aerobic oxidation and of its putative pro-oxidant activity to mammalian cell cultures (LLC-MK2 and RKO cell linages) and to Trypanosoma cruzi trypomastigotes. Here we show that, similar to ALA and AA, DAB undergoes aerobic oxidation in presence of phosphate ions and of transition metal ions such as Fe(II) and Cu(II), yielding oxygen radicals, H2O2, NH4+ and 2-oxo-4-aminobutanal accompanied by its condensation cyclic products displaying pyrrolic characteristics. Oxidative alterations to ferritin, apotransferrin and liposomes of cardiolipin and phosphatidylcholine (20:80) were observed under DAB treatment strongly supporting our hypothesis of DAB pro-oxidative activity. DAB treatment of mammalian cultured cells LLC-MK2 (IC50 1.5 mM, 24 h incubation) and RKO (IC50 0.3 mM, 24 h incubation) resulted in redox imbalance, induction of antioxidant response, activation of apoptosis pathway and cell cycle arrest. DAB is shown here to trigger Trypanosoma cruzi trypomastigotes decreased parasite motility and viability (IC50 0.2 mM, 4 h incubation), as well as redox thiol imbalance parallel to increase TcSOD activity. In addition, DAB efficiently hampered host cell (LLC-MK2) invasion by trypomastigotes...

Aspectos comparativos da resposta inflamatória em lesões de leishmaniose cutânea localizada e disseminada / Comparative aspects of the inflammatory response in lesions of cutaneous leishmaniasis and disseminated

A forma clínica mais frequente das leishmanioses é a leishmaniose cutânea, que acomete somente a pele e constitui um importante problema de saúde no Brasil. A leishmaniose cutânea caracteriza-se por lesão cutânea ulcerada única: leishmaniose cutânea localizada, que pode regredir espontaneamente ou se disseminar com múltiplas úlceras e pápulas e que aparecem em diferentes locais. A presença de disseminação caracteriza a leishmaniose cutânea disseminada. Investigar, no tecido, células que compõem o infiltrado inflamatório em lesões de pele na leishmaniose e caracterizar a resposta imune e sua correlação com a extensão total da inflamação in situ pode contribuir para aprofundar o entendimento da leishmaniose cutânea. Neste estudo, através da imunomarcação e quantificação de células por imunoistoquímica e HE, e análise da extensão da inflamação, foi comparado a histopatologia e presença de células inflamatórias CD4+, CD8+, CD68+, CD20+, plasmócitos e neutrófilos, e células granzima B+ em biópsias de pacientes com leishmaniose cutânea tardia (úlcera tardia e úlcera recente) e leishmaniose disseminada (úlcera e pápula). A análise dos padrões histomorfológicos mostrou semelhança entre os quatro grupos de biópsias analisados. Avaliando o número e tipo de células presentes, o predomínio foi de macrófagos e infócitos. As úlceras da leishmaniose cutânea clássica e disseminada apresentaram média maior de inflamação, maior frequência de linfócitos T CD4+, T CD8+, macrófagos, linfócitos B CD20+ e plasmócitos que úlceras recentes e pápulas. Estas, por sua vez, ao contrário das úlceras tardias de ambas formas clínicas, tiveram correlação positiva entre o aumento do infiltrado inflamatório e T CD4+ e T CD8+, e não correlação com granzima B e neutrófilos. Os plasmócitos se mostraram elementos quase constantes no infiltrado das lesões em todos os grupos, e sua frequência foi maior que de linfócitos B. Seguindo o mesmo padrão descrito nos linfócitos B, os plasmócitos não apresentam correlação com o influxo de infiltrado inflamatório entre os grupos. A frequência de macrófagos é vista nos dois estágios avaliados da doença e nas duas formas clínicas de forma semelhante, porém com uma tendência para maior presença em lesões de LD. A análise de neutrófilos revelou semelhança da frequência dessas células em todos os tipos de lesões em ambas formas clínicas, com as pápulas tendendo para uma menor quantidade. Portanto, o desenvolvimento das lesões ocorrem com o influxo de células inflamatórias, como linfócitos T CD4+ e T CD8+ e a resposta imune celular é mais intensa em lesões crônicas da leishmaniose cutânea localizada e disseminada do que em lesões localizadas recentes e pápulas da leishmaniose disseminada. Diferenças in situ na resposta inflamatória destas duas formas clínicas e quatro espectros de lesão da leishmaniose humana podem elucidar o papel de células no local da lesão e contribuir para o entendimento da patogênese da leishmaniose.

Cutaneous leishmaniasis is the most frequent clinical form of leishmaniasis, which affects only the skin and is an important health problem in Brazil. Cutaneous leishmaniasis is characterized by single ulcerated skin lesion: localized cutaneous leishmaniasis, which may regress spontaneously or spread with multiple ulcers and papules that appear in different parts of the body. The presence of dissemination features disseminated leishmaniasis. Investigate tissue cells from inflammatory infiltrate in skin lesions in leishmaniasis and characterize the immune response and its correlation with the total extent of inflammation in situ may contribute to deepen the understanding of cutaneous leishmaniasis. In this study, immunostaining and cells quantification by immunohistochemistry and HE and analysis of inflammation extention was compared with histopathology and CD4+, CD8+, CD68+, CD20+, plasma cells, neutrophils and granzyme B+ cells in biopsies of patients with localized cutaneous leishmaniasis (late ulcer and recent ulcer) and disseminated leishmaniasis (ulcers and papules). The histopathological patterns analysis was similar among the four biopsies groups analyzed. Macrophages and lymphocytes were the predominant cells. The ulcers of localized cutaneous leishmaniasis and disseminated leishmaniasis presented higher mean inflammation, increased frequency of CD4+ and CD8+ T cells, macrophages, B lymphocytes CD20+ and plasma cells than recent ulcers and papules. These, in turn, unlike late ulcers of both clinical forms, had positive correlation between the increase in inflammatory infiltrate and CD4+ and CD8+ T cells, differing in Granzyme B and neutrophils. Plasma cells were almost constant in lesion infiltrate in all groups and was higher than the frequency of B lymphocytes. Following the same pattern described in B lymphocytes, plasma cells did not show an association with the influx of inflammatory infiltrate between groups. The frequency of macrophages is seen in both stages of the disease and in the two clinical forms similarly, but with a tendency to be increased in disseminated lesihmaniasis lesions. The analysis revealed similarity of neutrophils frequency in all types of lesions, with papules tending to a lesser extent. Therefore, the development of lesions occur with the influx of inflammatory cells such as CD4+ and CD8+ T cells and cellular immune response is more intense in chronic lesions of localized cutaneous leishmaniasis and disseminated leishmaniasis than recent localized lesions and papules from disseminated leishmaniasis. Differences of inflammatory response in situ in these two clinical forms and four spectra of human leishmaniasis lesions may elucidate the role of cells at the lesion site and contribute to the understanding of leishmaniasis pathogenesis.

Accommodating the difference in students' prior knowledge of cell growth kinetics

This paper describes the development and benefits of an adaptive digital module on cell growth to tackle the problem of educating a heterogeneous group of students at the beginning of an undergraduate course on process engineering. Aim of the digital module is to provide students with the minimal level of knowledge on cell growth kinetics they need to comprehend the content knowledge of the subsequent lectures and pass the exam. The module was organised to offer the subject matter in a differentiated manner, so that students could follow different learning paths. Two student groups were investigated, one consisting of students who had received their prior education abroad and one of students that had not. Exam scores, questionnaires, and logged user data of the two student groups were analysed to discover whether the digital module had the intended effect. The results indicate that students did indeed follow different learning paths. Also, the differences in exam scores between the two student groups that was present before the introduction of the digital module was found to have decreased afterwards. In general, students appreciated the use of the material regardless of their prior education. We therefore conclude that the use of adaptive digital learning material is a possible way to solve the problem of differences in prior education of students entering a course.

Fisiologia: texto y atlas

Tratada de la fisiología del cuerpo humano, sus sistemas y aparatos y los numerosos procesos que los mantienen en funcionamiento.

Expressão gênica diferencial de lesões pré-neoplásicas hepáticas de ratos Wistar tratados com o quimiopreventivo Beta-ionona (BetaI): receptores nucleares como alvos moleculares do composto bioativo de alimentos / Differential gene expression of hepatic pre-neoplastic lesions of rats treated with the chemopreventive Beta-ionone (I): nuclear receptors as molecular targets of bioactive compound foods

A β-ionona (BI) é um isoprenóide que apresenta atividade quimiopreventiva durante a fase de promoção da hepatocarcinogênese. O presente trabalho teve como objetivo avaliar a expressão de genes modulados pela BI envolvidos na quimioprevenção durante a fase de promoção da hepatocarcinogênese induzida pelo modelo do "Hepatócito Resistente" (RH). Ratos Wistar machos foram submetidos ao modelo do RH e tratados durante 4 semanas consecutivas com BI (16 mg/100 g de p.c.) ou óleo de milho (OM) (0,25 ml/100 g de p.c.; grupo controle). O perfil da expressão de 1.176 genes foi analisado por macroarray no fígado dos grupos BI, OM e de ratos considerados normais (grupo N). A expressão gênica foi considerada aumentada, quando a razão de expressão foi ≥ 1,5 ou diminuída, quando ≤ 0,5. Aplicou-se análise hierárquica de clustering e classificação ontológica dos genes diferencialmente expressos. A expressão gênica foi validada por RT-PCR do tipo "duplex", utilizando-se tecido hepático microdissecado de: lesões pré-neoplásicas persistentes (pLPN) ou em remodelação (rLPN) e de regiões ao redor das LPN (surrounding). Um total de 133 e 32 genes foi considerado diferencialmente expresso entre os grupos OM (em relação ao N) e BI (em relação ao OM), respectivamente. Trinta e sete por cento dos genes diferencialmente expressos no grupo BI vs OM referiam-se a receptores celulares. Destes, 4 genes codificantes para receptores nucleares foram identificados como possíveis alvos da BI na quimioprevenção da hepatocarcinogênese: RXRα (receptor X de retinóide α), RARβ (receptor de ácido retinóico β), COUP-TFI (chicken ovalbumin upstream promoter-transcription factor I) e Nur77 (nuclear receptor 77). Em comparação ao grupo OM, a expressão de RXRα e RARβ foi maior (p<0,05) especificamente em pLPN e rLPN do grupo βI, respectivamente. Em comparação ao grupo N, Nur77 apresentou maior (p<0,05) expressão no surrounding e nas rLPN do grupo OM. Por outro lado, a expressão de Nur77 em rLPN foi menor...

Mecanismos celulares e moleculares de ação dos glicocorticóides endógenos sobre a mobilização de neutrófilos / Cellular and molecular mechanisms of action of endogenous glucocorticoids on the neutrophil mobilization

Temos mostrado que os glicocorticóides endógenos (GE) modulam o rolling e a aderência de neutrófilos in vivo, mediando a expressão de moléculas de adesão no leucócito e no endotélio. Adicionalmente, os GE controlam a maturação neutrofílica na medula e a sua mobilização para o sangue periférico. O presente trabalho visou investigar os mecanismos moleculares e celulares envolvidos na modulação exercida pelos GE neste processo. Utilizando ratos Wistar submetidos à adrenalectomia bilateral, tratados com RU 38486 ou controles (falso-operados, tratados com veículo ou não manipulados), foi demonstrado que: 1) os GE controlam, negativamente, a expressão de L-selectina em neutrófilos circulantes e ICAM-1, VCAM-1, PECAM-1, VAP-1 na célula endotelial e, positivamente, a expressão de L-selectina em granulócitos da medula óssea via seu receptor citosólico (GCR); 2) o mecanismo envolvido no controle dos GE sobre a expressão de L-selectina é independente de ação sobre sua expressão gênica ou da atividade de NFkB, mas dependente da expressão de anexina-A1, como verificado em camundongos knockouts (KO) para esta proteína 3) o controle da expressão de moléculas de adesão endotelial é dependente de ações sobre a expressão gênica, via translocação nuclear do NFkB; 4) a neutrofilia detectada em animais adrenalectomizados (ADR) é mediada pelo GCR, e dependente de anexina- A1; 5) a neutrofilia parece ser dependente da ação da anexina-A1 sobre a secreção de SDF-1 na medula óssea e expressão de CXCR-4 em neutrófilos circulantes e da medula; 6) concentrações circulantes elevadas de GE induzidas pela administração de ACTH confirmaram o controle dos GE, via anexina A-1, sobre o tráfego de neutrófilos da medula óssea para o sangue, mas sugerem um controle diferencial dos GE e anexina A-1 sobre a expressão de L-selectina em células da medula e do sangue circulante. Estes dados mostram mecanismos inéditos do controle dos GE sobre o tráfego de neutrófilos, que diferem em cada microambiente...

We have shown that endogenous glucocorticoids (GE) modulate the rolling and adhesion of neutrophils in vivo, mediating the expression of adhesion molecules on leukocytes and the endothelium. Additionally, the GE control neutrophil maturation in bone marrow and mobilization to peripheral blood. This work aimed to investigate the molecular and cellular mechanisms involved in the modulation exerted by GE in this process. Using male Wistar rats, submitted to bilateral adrenalectomy, treatment with RU 38 486 or controls (sham operated, vehicle or non manipulated), it was shown that: 1) GE control, negatively, L-selectin expression on circulating neutrophils and ICAM-1, VCAM-1, PECAM-1, VAP-1 on endothelial cell and, positively, L-selectin expression on bone marrow granulocytes via their cytosolic receptor (GCR); 2) the mechanism involved in the control of GE on the L-selectin expression is independent of its action on gene expression or NFkB activity, but dependent on the expression of anexina-A1, as observed in mice knockouts for this protein; 3) the control of endothelial adhesion molecules is dependent on gene expression, via NFkB translocation; 4) the neutrophilia detected in adrenalectomized animals (ADR) is mediated by GCR, and dependent on anexina-A1; 5) the neutrophilia seems to be dependent on the action of annexin A-1 on SDF-1á secretion in bone marrow and expression of CXCR-4 in peripheral blood and bone marrow; 6) high circulating concentrations of GE induced by administration of ACTH confirmed the control of GE, via the annexin-1, on the traffic of neutrophils from the bone marrow to the blood, but suggest a differential control of GE and annexin A-1 on the L-selectin expression in the bone marrow and circulating blood. These data indicate unpublished mechanisms of control of GE on the traffic of neutrophils, which differ in each microenvironment and cell type involved in this complex phenomenon.

Fisiología del condrocito articular / Physiology of articular cartilage

El condrocito es la única célula presente en el cartílago articular, por lo que es de gran importancia el conocimiento de los mecanismos que regulan sus funciones, en particular los mecanismos de transporte de membrana que le permiten a esta célula enfrentar los continuos cambios de la osmolaridad externa a que están sometidos como consecuencia de las variaciones en la carga mecánica. Los mecanismos implicados en la regulaciín del volumen intracelular, el pH intracelular, la concentraciín citoplásmica de calcio y el potencial de membrana son claves para la comprensiín de los procesos que se afectan con el desarrollo de la enfermedad, puesto que cualquier alteraciín de la homeostasis del condrocito articular afecta el metabolismo de los componentes de la matriz extracelular y por ende, las características funcionales del tejido. El presente artículo revisa los principales elementos funcionales del condrocito articular y su entorno en el contexto del transporte de membrana y su regulaciín.

The chondrocyte is the only cell in the articular cartilage; for this reason it is very important the knowledge about mechanisms that regulate its functions, particularly the membrane transport mechanisms which allow this cell to cope the continuous changes of external osmolarity as a consequence of variations in mechanic load. The mechanisms implied in regulation of cell volume, intracellular pH, cytoplasmic calcium concentration and membrane potential are key factors for understanding the process that are affected during illness, because any alteration of articular chondrocyte homeostasis affects the metabolism of the components of extracellular matrix and tissue functional characteristics. The present paper reviews the main functional elements of articular chondrocytes and its environment in the context of membrane transport regulation.

Actividad de los genes tipo MSX-1 durante el desarrollo craneofacial / Activity of MSX-1 type genes during craniofacial development

El gen MSX-1 es un miembro de la familia de genes homeobox MSX que cumple múltiples funciones durante el proceso de organogénesis. Este gen es expresado en sitios donde son requeridas interacciones epitelio-mesénquima y parece tener una función importante en el control del desarrollo craneofacial y dental, como lo demuestran los múltiples estudios en ratones y humanos. Este artículo revisa diferentes estudios con el objetivo de identificar las interacciones fisiológicas y patológicas de MSX-1 durante los diferentes estadíos de desarrollo craneofacial y dental.

MSX-1 gene is a member of the MSX homeobox gene family and it has different functions during the organogenesis process. This homeobox gene is expressed in sites where epithelium-mesenchyme interactions are required. It also seems to have an important activity controlling dental and craniofacial development, as investigated in human and murine models. The following article reviews severasl studies in order to identify MSX.1 relationships with dental and craniofacial development.

Medicina: quántica y homeopatía / Medicine: Homeopathy and quantum

La fisiología celular es el estudio de las actividades vitales químicas-físicas de las células y su interacción. Por lo tanto, es posible comparar la célula con una máquina. El investigador, en primer lugar, debe analizar la naturaleza de esta máquina a nivel intracelular, para comprender los principios que gobiernansu funcionamiento, buscando con ello un mejor entendimiento de su funcionalidad metabólica. Por tal motivo, es importante considerar la termodinámica y el flujo de energía en los sistemas biológicos celulares que siempre están presentes. Es aquí en donde la quántica ocupa un gran papel en la investigación de la energía existente de los espacios intra-extra celular e intersticial de los tejidos y órganos vitales en general.

Eritropoyesis y esplenectomía en un modelo murino / ERITHROPOIESIS AND SPLENECTOMY IN A MURINE MODEL

Introducción: El bazo del ratón adulto participa en la recuperación del eritrón porque su estroma aporta un microentorno adecuado para la proliferación y maduración de progenitores. Objetivo: Evaluar por estudios morfológicos el grado de eritropoyesis hepática y renal en ratones esplenectomizados en respuesta a la hemólisis inducida por fenilhidrazina (FHZ). Materiales y Métodos: Ratones hembra CF1(30±3g) fueron agrupados en:1)GRUPO CONTROL (GC)(n=18): solución fisiológica (SF) intraperitoneal (ip) (300µL;días:0,2) postcirugía simulada; 2)GRUPO ANÉMICO (GA) (n=18): FHZ ip (60mg/Kg/ 300mL;días:0,2) postcirugía simulada;3)GRUPO ESPLENECTOMIZADO NO ANÉMICO(GENA) (n=18): SF ip postesplenectomía (300mL;días:0,2); 4) GRUPO ESPLENECTOMIZADO ANÉMICO (GEA)(n=18): FHZ ip (60mg/Kg/ 300mL;días:0,2) postesplenectomía. Sangre venosa: cada 2 días hasta el día 10 (n=3). Parámetros evaluados: Hb, HCT, reticulocitos y cuerpos de Heinz. La esplenectomía se realizó bajo anestesia. Los tejidos fueron fijados con Bouin y Formol 10% y procesados para Hematoxilina- Eosina. Islotes eritropoyéticos (IE) semicuantificados por un escore preestablecido. Resultados: Los grupos anémicos, con y sin bazo, mostraron hemólisis franca el día 4. La recuperación de la anemia fue el día 6 en el GA y el día 10 en el GEA. Reticulocitosis máxima: día 8 en el GEA y día 6 en el GA. Cuerpos de Heinz: elevados hasta el día 6 en GA y hasta el día 8 en GEA. Se observaron abundantes IE en hígado y en menor grado en riñón. Conclusiones: La recuperación eritropoyética en ratones esplenectomizados fue asumida principalmente por el hígado. La restauración tardía evidenció que el bazo es el órgano que compensa con mayor eficiencia la crisis hemolítica en esta cepa de ratones.

Introduction: The spleen of the adult mouse takes part in the recovery of erythron because its stroma provides a micro-environment that is adequate for progenitor proliferation and maturing. Objective: To assess, by means of morphological studies, the degree of hepatic and renal erythropoiesis in splenectomized mice in response to phenylhydrazine (PHZ)-induced hemolysis. Materials and Methods: Female mice CF1(30±3g) were grouped into: 1) CONTROL GROUP (CG) (n=18): intraperitoneal (ip) physiological solution (PS) (300 µL; days: 0,2) post simulated surgery; 2) ANEMIC GROUP (AG) (n=18): ip PHZ (60 mg / Kg / 300mL; days: 0, 2) post simulated surgery; 3) SPLENECTOMIZED NON- ANEMIC GROUP (SNAG) (n=18): ip PS postsplenectomy (300mL; days: 0, 2); 4) SPLENECTOMIZED ANEMIC GROUP (SAG) (n=18): ip PHZ (60 mg / Kg / 300 mL; days: 0, 2) post-splenectomy. Venous blood: every 2 days until day 10 (n=3). Parameters assessed: Hb, HCT, reticulocytes, and Heinz bodies. The splenectomy was performed under anesthesia. Tissues were fixed using Bouin and 10% Formalin and processed for Hematoxilin- Eosin. Erythropoietic Islands (EI) were semi-quantified by a pre-established score. Results: Anemic groups, with and without the spleen, showed marked hemolysis on day 4. Anemia recovery took place on day 6 in the AG and on day 10 in the SAG. Maximum Reticulocytosis: day 8 in the SAG and day 6 in the AG. Heinz Bodies were high until day 6 in AG and until day 8 in SAG. Abundant EI were observed in the liver and in a smaller degree in the kidney. Conclusions: Erythropoietic recovery in splenectomized mice was mainly assumed by the liver. Late restoration showed that the spleen is the organ that most efficiently compensates the hemolytic crisis in this mice strain.

Death by fine tunning

Since the first evidence that physiological cell death is a normal feature of cell life, there has been considerable effort in trying to define the mechanisms, regulation and morphology of cell death events. In nearly four decades of investigation, several types of cell death have been described in a wide range of organisms and cells, and this has led to great deal of confusion regarding the morphology and regulation of these processes. Historically, cell death has been characterized as physiological or accidental (necrosis). However, in the past fi ve years, several attempts have been made to define the types of cell death based on mechanistic and morphological criteria. Currently, at least three types of cell death apoptosis, autophagy and necrosis are recognized and share some mechanisms in common. Thus, cell death is more than simply being a caspase-mediated phenomenon. The aim of this review is to discuss recent findings on how cells choose to die in different biological contexts, and to consider the morphological changes associated with each cell type of cell death.