Glucocorticoid effect on human mesangial cell cytoskeletal proteins.
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.
Koukouritaki
S B
SB
Cardiovascular Research Center, Nephrology, Medical College of Wisconsin, Milwaukee, USA.
Lianos
E A
EA
D015815:Cell Adhesion Molecules / Q000378:metabolism; D002461:Cell Line, Transformed; D003571:Cytochalasin B / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D005920:Glomerular Mesangium / Q000187:drug effects* / Q000378:metabolism* / Q000648:ultrastructure; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007163:Immunosorbent Techniques; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism
D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D005938:Glucocorticoids; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D019000:Phosphotyrosine; D003571:Cytochalasin B; D003907:Dexamethasone; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human