Tau-like immunoreactivity in Alzheimer and control skin fibroblasts.
The presence of the microtubule-associated protein tau in skin fibroblasts derived from Alzheimer patients and normal controls was investigated using a panel of well-characterized anti-tau antibodies against epitopes spanning the tau protein from the amino to the carboxyl end. The antibodies immunolabeled a fine, fibrillar cytoplasmic network in all skin fibroblasts. Disruption of the microtubule network with colchicine did not affect the immunolabeling of the fibrillar network nor did treatment with cytochalasin B known to disrupt the microfilament network. Immunoelectron microscopy with the anti-tau antibodies revealed colocalization of the label with the 10 nm intermediate filaments. Furthermore, immunoblots found no reactivity against purified vimentin, suggesting that the antibodies recognize an intermediate filament-associated protein. The findings indicate the presence of tau or a protein with considerable homology to tau in fibroblasts associated with intermediate filaments and not microtubules.
Matsuyama
S S
SS
Psychogeriatric Unit and Laboratory, West Los Angeles Veterans Affairs Medical Center, Brentwood Division, CA 90073.
Bondareff
W
W
D008841:Actin Cytoskeleton / Q000187:drug effects; D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology*; D003078:Colchicine / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D000939:Epitopes / Q000276:immunology; D005347:Fibroblasts / Q000737:chemistry* / Q000648:ultrastructure; D006801:Humans; D007382:Intermediate Filaments / Q000737:chemistry* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008870:Microtubules / Q000187:drug effects; D012867:Skin / Q000737:chemistry / Q000473:pathology; D016875:tau Proteins / Q000032:analysis* / Q000276:immunology
D000939:Epitopes; D016875:tau Proteins; D003571:Cytochalasin B; D003078:Colchicine