Abstract
In human mesangial cells (HMCs), we assessed the effect of dexamethasone on the expression and levels of tyrosine phosphorylation of two cytoskeleton-associated proteins: focal adhesion kinase (FAK) and paxillin. Dexamethasone, 10(-7) mol/L, increased levels of tyrosine phosphorylation of both proteins within 15 to 30 minutes without a change in protein levels. The exposure of HMCs to cytochalasin B, a disrupter of the cytoskeleton assembly, reduced basal tyrosine phosphorylation of both proteins. This effect was reversed by dexamethasone. These observations support a stabilizing effect of dexamethasone on the mesangial cell cytoskeleton. This may constitute a cytoprotective mechanism in the context of the anti-inflammatory action of the steroids in various glomerulopathies.
MeSH terms
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Cell Adhesion Molecules / metabolism
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Cell Line, Transformed
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Cytochalasin B / pharmacology
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Cytoskeletal Proteins / metabolism*
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Cytoskeleton / drug effects
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Dexamethasone / pharmacology
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Focal Adhesion Kinase 1
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Focal Adhesion Protein-Tyrosine Kinases
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Glomerular Mesangium / drug effects*
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Glomerular Mesangium / metabolism*
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Glomerular Mesangium / ultrastructure
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Glucocorticoids / pharmacology*
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Humans
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Immunosorbent Techniques
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Paxillin
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Phosphoproteins / metabolism
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Phosphorylation
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Phosphotyrosine / metabolism
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Protein-Tyrosine Kinases / metabolism
Substances
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Cell Adhesion Molecules
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Cytoskeletal Proteins
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Glucocorticoids
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PXN protein, human
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Paxillin
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Phosphoproteins
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Phosphotyrosine
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Cytochalasin B
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Dexamethasone
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Protein-Tyrosine Kinases
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Focal Adhesion Kinase 1
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Focal Adhesion Protein-Tyrosine Kinases
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PTK2 protein, human