Degranulation and superoxide production depend on cholesterol in PLB-985 cells.
The effect of agents disrupting cholesterol-rich microdomains of the cell membrane was studied on the chemoattractant receptor (FPR and FRPL1) coupled effector responses of promyelocytic PLB-985 cells. Both methyl-beta-cyclodextrin (MbetaCD) and filipin III inhibited exocytosis of primary granules and O(2)(.-) production induced by stimulation of either chemotactic receptor. Alteration of calcium homeostasis of MbetaCD-treated cells does not account for the impairment of the effector responses. Disruption of microfilaments by cytochalasin B (CB) partially reverses the inhibitory effect of cholesterol depletion. Our results provide functional support for the involvement of cholesterol-rich membrane domains in the signaling of chemotactic receptors and call the attention to the possible role of microfilaments in the organization of lipid microdomains.
Káldi
Krisztina
K
Department of Physiology, Semmelweis University, POB 259, H-1444 Budapest, Hungary.
Kalocsai
Agnes
A
Rada
Balázs K
BK
Mezo
Gábor
G
Molnár
Gergely Z
GZ
Báthori
György
G
Ligeti
Erzsébet
E
D000595:Amino Acid Sequence; D015550:Cell Degranulation / Q000187:drug effects; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism*; D003505:Cyclodextrins / Q000494:pharmacology; D005372:Filipin / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D013481:Superoxides; D005372:Filipin; D002784:Cholesterol