Filipin, a polyene antibiotic known to induce leakage of materials from various cells, depresses K(+) and NO(3) (-) uptake in etiolated pea epicotyl segments. Filipin concentrations which strongly reduce K(+) influx have little effect on efflux; however, high concentrations enhance K(+) efflux. Filipin has no effect on respiration rates or cell electropotentials; its action is presumed to be on...

The polyene antibiotic, filipin, by specifically interacting with cholesterol, produces approximately 25-nm protuberances (filipin-sterol complexes) in freeze-fractured membranes, and the addition of filipin to aldehyde fixatives has been recently introduced as a cytochemical technique for the localization of cholesterol in cell membranes. In a previous study we showed that, in fibroblasts fili...

BACKGROUND Streptomyces filipinensis is the industrial producer of filipin, a pentaene macrolide, archetype of non-glycosylated polyenes, and widely used for the detection and the quantitation of cholesterol in biological membranes and as a tool for the diagnosis of Niemann-Pick type C disease. Genetic manipulations of polyene biosynthetic pathways have proven useful for the discovery of produc...

Effects of a complex polyene antibiotic, filipin, and its four components were studied upon biological (erythrocyte) and artificial (liposome) membranes in order to test the “sterol receptor” hypothesis of polyene action. The hemolytic activity of filipin complex could be removed more effectively by liposomes which had cholesterol incorporated (phosphatidyl choline (7)~dicetylphosphate (2)-chol...

Specialized areas wi th in broad, close, cell-substratum contacts seen with reflection interference contrast microscopy in cultures of Xenopus embryonic muscle cells were studied. These areas usually contained a distinct pattern of l ight and dark spots suggesting that the closeness of apposit ion between the membrane and the substratum was irregular. They coincided with areas containing acetyl...

The polyene antibiotic filipin reacts specifically with membrane cholesterol and produces distinctive membrane lesions. We treated frog cutaneous and sartorius muscles with 0.04% filipin in a glutaraldehyde solution with or without prefixation with glutaraldehyde. Freeze-fracture of these muscles revealed numerous 19 to 38-nm protuberances and depressions (filipin-sterol complexes) in most area...

The rims of vesicle openings in capillary endothelium are reported to be highly sensitive to perturbation by the sterol probe filipin when this agent is administered by perfusion at 50 microM concentration in aldehyde fixative for 10 min. If, as supposed, this specific rim response reflects functionally significant aspects of membrane organization at the vesicle-plasmalemma boundary, then it wo...

Background Chronic obstructive pulmonary disease (COPD) is characterized by inflammation, airflow obstruction, and lung damage resulting from multiple causes, in particular the exposure to cigarette smoke. Growing evidence supports an important role for lipid metabolism development of COPD, where ferroptosis plays a critical cholesterol homeostasis. The aim present study was investigate smoke e...

Filipin has been widely used as an electron microscopic probe to detect 3-beta-hydroxysterols, principally cholesterol, in cellular membranes. When it complexes with sterol, it forms globular deposits that disrupt the planar organization of the membrane. Previous studies have shown that coated pits and coated vesicles, specialized membranes involved in receptor-mediated endocytosis, do not appe...

Niemann-Pick disease type C is a clinically heterogeneous storage disorder with an unknown primary metabolic defect. We have undertaken somatic cell hybridisation experiments using skin fibroblast strains from 12 patients representing a wide clinical spectrum. Preliminary experiments using filipin staining of free cholesterol as a marker for complementation indicated the existence of one major ...