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| KUSNIER,CARLOS; CÁRDENAS,CÉSAR; HIDALGO,JORGE; JAIMOVICH,ENRIQUE. |
| Nuclear calcium appears to have an important role in the regulation of gene expression in many cells, but the mechanisms involved in controlling nuclear Ca2+ signaling are controversial and still poorly understood. We have described the presence of inositol 1,4,5 trisphosphate (IP3) receptors in the nuclei of skeletal muscle cells. Now, we have characterized the properties of the IP3 receptors channels present in the nuclei of the 1B5 cell line, which do not express any isoforms of the ryanodine receptor. Immunocytochemistry of isolated nuclei confirmed the presence of IP3R in the nuclear envelope and fluorescence measurements in nuclei suspensions allowed us to document ATP-dependent calcium loading by the nucleus and its release upon IP3 addition. Patch... |
| Tipo: Journal article |
Palavras-chave: Single channel; Cell nucleus; IP3 receptor; Muscle. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300015 |
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| MOLGÓ,JORDI; COLASANTE,CESARE; ADAMS,DANY S; JAIMOVICH,ENRIQUE. |
| In this short article we review muscle satellite cell characteristics and our studies in adult rodent muscle satellite cells in situ. Using confocal laser scanning microscopy and immunocytochemistry, a high level of IP3 receptor (IP3R) immunostaining was detected in satellite cells. These cells were identified by their peripheral position, their size, the shape of their nucleus, the paucity of the apparent cytoplasm, and the immunostaining with specific molecular markers such as a-actinin, the neural cell adhesion molecule (N-CAM) and desmin. High extracellular K+ (60 mM) induced long-lasting Ca2+ signalsin satellite cells in situ. We suggest that electrical activity stimulates IP3-associated Ca2+ signals that could act in concert with signaling pathways... |
| Tipo: Journal article |
Palavras-chave: Muscle satellite cells Inositol 1; 4; 5-trisphosphate receptors intracellular Ca2+ Signal transduction. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400019 |
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| JAIMOVICH,ENRIQUE; ESPINOSA,ALEJANDRA. |
| We studied the effect of IGF-I, insulin and testosterone on intracellular Ca2+ in cultured muscle cells. Insulin produced a fast (<1 s) and transient [Ca2+] increase lasting less than 10 s. IGF-I induced a transient [Ca2+] increase, reaching a fluorescence peak 6 s after stimulus, to return to basal values after 60 s. Testosterone induced delayed (35 s) and long lasting (100-200 s) signals, frequently associated with oscillations. IGF-I, testosterone and electrical stimulation-induced Ca2+ signals were shown to be dependent on IP3 production. All of these Ca2+ signals were blocked by inhibitors of the IP3 pathway. On the other hand, insulin-induced Ca2+ increase was dependent on ryanodine receptors and blocked by either nifedipine or ryanodine. The... |
| Tipo: Journal article |
Palavras-chave: Skeletal; Transcription factors; Insulin; IGF-I; Testosterone. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400018 |
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