Alterations in lipid fluidity induced by cholesterol and cholesterol hemisuccinate modulate the organization of microtubule skeletons in epithelial cells.
This study was designed to evaluate the role that cholesterol, and the more hydrophilic ester, cholesterol hemisuccinate (CHS) have on the ability of epithelial cells to attach, spread and reorganize microtubule skeletons on a defined substratum. A431 carcinoma cells were grown and incubated with cholesterol, or CHS in polyvinyl pyrrolidone. Subsequently the cells were plated either on plastic petri dishes or plasticware coated with collagen IV or laminin. The alteration in apparent membrane microviscosity was ascertained using fluorescence polarization measurements. Organization of microtubules was determined by immunofluorescence, and by transmission electron microscopy. Cholesterol and CHS inhibited attachment and spreading of epithelial cells. Cells previously attached and spread became spherical after treatment with cholesterol and CHS, but microtubules were unaffected. However, when the cells were pretreated in suspension with cholesterol or CHS the membrane microviscosities markedly increased, and upon subsequent plating those cells adhering neither spread nor organized microtubule skeletons. These results suggest that cholesterol-induced changes in lipid microviscosity modulate the membrane dynamics that control the ability of epithelial cells to attach, spread and organize microtubule skeletons.
D002277:Carcinoma / Q000503:physiopathology / Q000648:ultrastructure*; D002448:Cell Adhesion; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002478:Cells, Cultured; D002784:Cholesterol / Q000494:pharmacology*; D002788:Cholesterol Esters / Q000494:pharmacology*; D004848:Epithelium / Q000503:physiopathology / Q000648:ultrastructure; D006801:Humans; D008055:Lipids / Q000502:physiology*; D014783:Viscosity
D002788:Cholesterol Esters; D008055:Lipids; D002784:Cholesterol; C013440:cholesteryl succinate