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| Registros recuperados: 13 | |
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| Bodi,Estevão; Hurtado,Sandra P.; Carvalho,Marcelo A.; Borojevic,Radovan; Carvalho,Antônio C. Campos de. |
| We examined gap junction communication in an in vitro model of hematopoiesis, using the murine bone marrow stroma cell line S-17, and primary cultures of murine marrow-derived blood cell precursors. S-17 cells express several connexins, the major one being connexin 43. Connexin expression and formation of functional gap junctions is modulated by stroma cell density. Transfection of S-17 cells with a vector containing connexin 43 sense or anti-sense sequences increased or decreased, respectively, connexin 43 synthesis and intercellular dye coupling. Under these conditions, modulation of gap junction-mediated communication modified the growth pattern of stroma itself, as well as the ability of the stroma to sustain hematopoiesis. Increased connexin 43... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bone marrow; Hematopoiesis; Connexins; Gap junctions; S-17 cells. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000400009 |
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| Menezes,J.R.L.; Marins,M.; Alves,J.A.J.; Fróes,M.M.; Hedin-Pereira,C.. |
| New neurons are constantly added to the olfactory bulb of rodents from birth to adulthood. This accretion is not only dependent on sustained neurogenesis, but also on the migration of neuroblasts and immature neurons from the cortical and striatal subventricular zone (SVZ) to the olfactory bulb. Migration along this long tangential pathway, known as the rostral migratory stream (RMS), is in many ways opposite to the classical radial migration of immature neurons: it is faster, spans a longer distance, does not require radial glial guidance, and is not limited to postmitotic neurons. In recent years many molecules have been found to be expressed specifically in this pathway and to directly affect this migration. Soluble factors with inhibitory, attractive... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Postnatal neurogenesis; Chain migration; Rostral migratory stream; Astrocytes; Gap junctions; Radial glia. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001200002 |
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| Nicholson,B.J.; Weber,P.A.; Cao,F.; Chang,H.-C.; Lampe,P.; Goldberg,G.. |
| Although gap junction channels are still widely viewed as large, non-specific pores connecting cells, the diversity in the connexin family has led more attention to be focused on their permeability characteristics. We summarize here the current status of these investigations, both published and on-going, that reveal both charge and size selectivity between gap junction channels composed of different connexins. In particular, this review will focus on quantitative approaches that monitor the expression level of the connexins, so that it is clear that differences that are seen can be attributed to channel properties. The degree of selectivity that is observed is modest compared to other channels, but is likely to be significant for biological molecules that... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Intercellular channels; Permeability; Channel selectivity; Gap junctions. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000400002 |
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| Most cells exchange ions and small metabolites via gap junction channels. These channels are made of two hemichannels (connexons), each formed by the radial arrangement of six connexin (Cx) proteins. Connexins span the bilayer four times (M1-M4) and have both amino- and carboxy-termini (NT, CT) at the cytoplasmic side of the membrane, forming two extracellular loops (E1, E2) and one inner (IL) loop. The channels are regulated by gates that close with cytosolic acidification (e.g., CO2 treatment) or increased calcium concentration, possibly via calmodulin activation. Although gap junction regulation is still unclear, connexin domains involved in gating are being defined. We have recently focused on the CO2 gating sensitivity of Cx32, Cx38 and various... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Cell-cell interaction; Cell junctions; Gap junctions; Calcium; Calmodulin; Membrane channels. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000500003 |
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| Sáez,J.C.; Brañes,M.C.; Corvalán,L.A.; Eugenín,E.A.; González,H.; Martínez,A.D.; Palisson,F.. |
| Gap junction channels are sites of cytoplasmic communication between contacting cells. In vertebrates, they consist of protein subunits denoted connexins (Cxs) which are encoded by a gene family. According to their Cx composition, gap junction channels show different gating and permeability properties that define which ions and small molecules permeate them. Differences in Cx primary sequences suggest that channels composed of different Cxs are regulated differentially by intracellular pathways under specific physiological conditions. Functional roles of gap junction channels could be defined by the relative importance of permeant substances, resulting in coordination of electrical and/or metabolic cellular responses. Cells of the native and specific... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cell contacts; Gap junctions; Connexins; Native immune response; Specific immune response; Inflammatory response. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000400011 |
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| Saffitz,J.E.. |
| Effective pump function of the heart depends on the precise control of spatial and temporal patterns of electrical activation. Accordingly, the distribution and function of gap junction channels are important determinants of the conduction properties of myocardium and undoubtedly play other roles in intercellular communication crucial to normal cardiac function. Recent advances have begun to elucidate mechanisms by which the heart regulates intercellular electrical coupling at gap junctions in response to stress or injury. Although responses to increased load or injury are generally adaptive in nature, remodeling of intercellular junctions under conditions of severe stress creates anatomic substrates conducive to the development of lethal ventricular... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gap junctions; Cardiac hypertrophy; Heart failure; Arrhythmias. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000400006 |
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| Registros recuperados: 13 | |
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