title: Altered lipid profile and changes in uroplakin properties of rat urothelial plasma membrane with diets of different lipid composition.
abstract: Rigid plaques containing protein particles in plasma membrane build on the apical surface of the mammalian urothelium. We have previously shown that dietary fats modified the fatty acid profile as well as the fluorescence anisotropy of rat urothelial plasma membranes. In this study, we have further examined the proportion of phosphatidylcholine, phosphatidylethanolamine, cerebrosides, sulfatides and cholesterol in detergent resistant (DRM) and soluble (DSM) plasma membrane fractions as well as the properties of the particles. Four groups of weaned rats were fed for 12 weeks on a commercial diet (control), or on a formula containing 5% (w/w) of corn oil, fish oil or olein. The control DRM behaved as a distinctive domain since it was enriched in cholesterol and glycosphingolipids. DSM showed higher levels of phosphatidylcholine and phosphatidylethanolamine with respect to DRM. On the other hand, the lipid distributions were affected by the diets. Homogeneous lipid distributions between DSM and DRM were found in olein membranes, suggesting a decreased potential formation of lipid domains. In addition, properties of the uroplakins were altered by dietary treatments. Thus, uroplakins (UP) Ia, Ib, II and III observed by SDS-PAGE, were in lower proportions (mainly olein) than in controls. Moreover, a higher proportion of UPIII was cross-linked to UPIII and UPlb in olein treatment than in control. Meanwhile, only cross-linking to UPIII or UPIb was altered in corn and fish diets, respectively. These results suggest a role of the lipids in the establishment of the uroplakin interactions. Thus, specific dietary fats may have important functional implications.
authors.affiliation: Instituto de Biología Celular, Ia Cátedra de Biología Celular Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Guillermina A
authors.initials: GA
authors.lastname: Bongiovanni
authors.forename: Aldo R
authors.initials: AR
authors.lastname: Eynard
authors.forename: Reyna O
authors.initials: RO
authors.lastname: Calderón
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism; D003314:Corn Oil / Q000494:pharmacology; D003902:Detergents / Q000737:chemistry / Q000494:pharmacology; D004032:Diet; D004041:Dietary Fats / Q000494:pharmacology; D005260:Female; D005395:Fish Oils / Q000494:pharmacology; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D059470:Tetraspanins; D060170:Uroplakin II; D060171:Uroplakin III; D060167:Uroplakin Ia; D060169:Uroplakin Ib; D019459:Urothelium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
chemical_list: D003902:Detergents; D004041:Dietary Fats; D005395:Fish Oils; D008055:Lipids; D008562:Membrane Glycoproteins; D008563:Membrane Lipids; D008565:Membrane Proteins; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D059470:Tetraspanins; C086451:UPK1A protein, human; C554658:UPK2 protein, human; C490124:Upk1b protein, mouse; C554659:Upk2 protein, mouse; D060170:Uroplakin II; D060171:Uroplakin III; D060167:Uroplakin Ia; D060169:Uroplakin Ib; D003314:Corn Oil; D002784:Cholesterol