Exposure to free fatty acid increases the transfer of albumin across cultured endothelial monolayers.

Abstract

An initial exposure to high concentrations of free fatty acid increased the transfer of albumin across cultured endothelial monolayers. The rate and amount of albumin transfer was dependent on the oleic acid concentration to which the cultures were initially exposed, with 300 p.M producing the maximum transfer. The albumin transfer also increased with the increasing time of exposure to oleic acid, the maximum effect occurring during the first 24 hours. An exposure to 300 juM linoleic acid produced an even greater increase in albumin transfer than did 300 /uM oleic acid. The increased albumin transfer observed when cells were exposed to high concentrations of free fatty acid was largely reversible after reincubation of the cell monolayers in free fatty acid-poor media. In parallel experiments, radioactive oleic acid incorporation into cell triglycerides increased linearly as the fatty acid concentration was raised, with cell triglyceride content increasing up to sevenfold after incubation in a medium containing 300 /nM oleic acid. A significant amount of oleic acid was incorporated into phospholipids, and the fatty acid composition of the endothelial triglycerides and phospholipids was modified. All these effects of oleic acid occurred without altering the incorporation of leucine into the cell protein. These results indicate that exposure to high concentrations of free fatty acid can alter endothelial cell lipid composition, and that this increases the albumin transfer across endothelium. This process might permit more macromolecules to enter the arterial wall. (Arteriosclerosis 4:489-497, September/October 1984)

Changes in Matrix Proteoglycans Induced by Insulin and Fatty Acids in Hepatic Cells May Contribute to Dyslipidemia of Insulin Resistance

“…However, Hennig and colleagues (10,(22)(23)(24)(25) found that linolenic acid and saturated fatty acids were less potent modulators than linoleic acid on endothelial barrier function and PG synthesis. Although the effects on smooth muscle and endothelial cells are not necessarily transferable to hepatic cells, the above considerations led us to choose linoleic acid as a first model to study NEFAs' effects on hepatic cells.…”

Lipids and the ocular lens

“…Lens cells actively transport albumin from the apical to the basolateral compartment in a process that involves caveolae and clathrin-coated vesicles (167)(168)(169). Micromolar concentrations of unsaturated fatty acids are cytotoxic to cultured bovine and human lens cells (170)(171)(172)(173)(174)(175). The aqueous humor of elderly patients who had cataracts contained micromolar levels of fatty acids and raises the possible involvement of these fatty acids in cataract formation.…”

“…The aqueous humor of elderly patients who had cataracts contained micromolar levels of fatty acids and raises the possible involvement of these fatty acids in cataract formation. In a number of pathophysiologic states related to cataract formation, fatty acid is elevated in blood [see references in ( 175,176 )]. Fatty acid exposure results in bleb formation where fatty acid molecules accumulate in the cells ( 174 ).…”

Localization of Lipoprotein Lipase in the Diabetic Heart

“…10 An oversupply of FFAs causes these cellular organelles to overproduce reactive oxygen species that can potentially contribute to the formation of lipid peroxidation products. 45,46 Lipolytic products have also been shown to enhance endothelial permeability, 47,48 whereas enhanced FFA metabolism in the heart can inhibit glucose oxidation. 49 The regulatory mechanisms governing changes in cardiac capillary-bound LPL in response to acute hypoinsulinemia are currently being investigated.…”