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Biomedical subjects

M H Delgrossi

Publications and source records attributed to M H Delgrossi.

4 recordsLinked to original sources
PubMed1997

Human syntaxin 3 is localized apically in human intestinal cells.

To understand the molecular mechanisms underlying sorting of apical and basolateral membrane components in human intestinal epithelial cells, we have cloned the human homolog of rat syntaxin 3 and looked for its subcellular localization. Endogenous human syntaxin 3 was found to be localized at the apical membrane of colon epithelial and Caco-2 cells. This apical localization was confirmed by confocal microscopy after transfection of the cDNA coding for either full length or N-terminally truncated human syntaxin 3 in Caco-2 cells. Furthermore the signal(s) and machinery targeting human syntaxin 3 to the apical membrane of epithelial cells are conserved between species since human syntaxin 3 was also localized at the apical membrane of canine MDCK cells and of epithelial cells in transgenic Drosophila melanogaster.

Animals↗
PubMed1996

Detergent-resistant membrane microdomains from Caco-2 cells do not contain caveolin.

In this study we analyzed the relationship between detergent-resistant microdomains and caveolae in Caco-2 cells. Caveolin was not detected on Western blots or Northern blots or by immunoprecipitation in these cells, in contrast to A 431 cells. Triton X-100-resistant membranes from Caco-2 and A 431 cells showed the same morphological aspect by electron microscopy and peaked at the same isopycnic density on sucrose gradients. Detergent-resistant microdomains from Caco-2 cells were enriched in glycosyl phosphatidylinositol (GPI)-anchored proteins, in sucrase-isomaltase, an apical marker, and in most of the proteins found in caveolin-rich membranes such as src-like proteins, fimbrin, ezrin, and Gi alpha. Caveolae-like structures were present in A 431 but absent from Caco-2 cells at the electron microscopic level. Detergent-resistant microdomains from Caco-2 cells resemble caveolin-rich microdomains in their molecular composition but do not seem to derive from morphologically identified caveolae. Our results also indicate that caveolin is not necessary for sorting of GPI-linked proteins to the apical membrane of Caco-2 cells.

Caco-2 Cells↗
PubMed1983

Muscle dedifferentiation and contractile protein synthesis during post-traumatic regeneration by Owenia fusiformis (polychaeta annelid).

During anterior traumatic regeneration of the polychaete annelid Owenia fusiformis, we have observed by electron microscopy the dedifferentiation processes of muscle cells. The dedifferentiated cells are reminiscent of undifferentiated myoblasts. They form the blastema and redifferentiate in muscle cells in the regenerate. The in vivo and in vitro biochemical studies of the biosynthesis of contractile proteins, as markers of the terminal differentiation programme of the muscle cells, showed that gene expression correlated with the terminal differentiation programme (at last for muscle cells) seemed unaffected. It seems in fact that contractile protein synthesis is regulated partly at the translational level during traumatic regeneration in the invertebrate.

Amputation, Surgical↗