Changes in mononuclear phagocyte microtubules after endotoxin stimulation. II. Changes in microtubule composition.
Microtubules are integral components of the cytoskeleton of human cells and are composed of alpha- and beta-tubulin as well as a variable number of microtubule-associated proteins. In monocytes and macrophages, microtubules bind endotoxin and partly regulate endotoxin-induced inflammatory events such as cytokine production. Endotoxin causes a rapid alteration in monocyte microtubule stability. To characterize the effect of endotoxin on mononuclear phagocyte microtubule composition, Western blots and flow cytometry were performed on human monocytes and the monocyte/macrophage-like cell line THP-1. Compared to unstimulated monocytes, monocytes stimulated with endotoxin for 18 h had increased quantities of alpha-, beta-, and tyrosinated alpha-tubulin as well as microtubule-associated protein-2. PMA-differentiated THP-1 cells had increased levels of alpha-tubulin, beta-tubulin, microtubule-associated protein-5, microtubule-associated protein-2, and tau after endotoxin stimulation. These results indicate that endotoxin can alter mononuclear phagocyte microtubules by causing an increase in certain microtubule component proteins.
Allen
J N
JN
Division of Pulmonary and Critical Care Medicine, Ohio State University, Columbus, USA.
Liao
Z
Z
Moore
S A
SA
Wewers
M D
MD
D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008870:Microtubules / Q000648:ultrastructure*
D008070:Lipopolysaccharides