Liver and intestinal fatty acid-binding protein expression increases phospholipid content and alters phospholipid fatty acid composition in L-cell fibroblasts

Lipids. 2000 Jul;35(7):729-38. doi: 10.1007/s11745-000-0579-x.

Abstract

Although fatty acid-binding proteins (FABP) differentially affect fatty acid uptake, nothing is known regarding their role(s) in determining cellular phospholipid levels and phospholipid fatty acid composition. The effects of liver (L)- and intestinal (I)-FABP expression on these parameters were determined using stably transfected L-cells. Expression of L- and I-FABP increased cellular total phospholipid mass (nmol/mg protein) 1.7- and 1.3-fold relative to controls, respectively. L-FABP expression increased the masses of choline glycerophospholipids (ChoGpl) 1.5-fold, phosphatidylserine (PtdSer) 5.6-fold, ethanolamine glycerophospholipids 1.4-fold, sphingomyelin 1.7-fold, and phosphatidylinositol 2.6-fold. In contrast, I-FABP expression only increased the masses of ChoGpl and PtdSer, 1.2- and 3.1-fold, respectively. Surprisingly, both L- and I-FABP expression increased ethanolamine plasmalogen mass 1.6- and 1.1-fold, respectively, while choline plasmalogen mass was increased 2.3- and 1.7-fold, respectively. The increase in phospholipid levels resulted in dramatic 48 and 33% decreases in the cholesterol-to-phospholipid ratio in L- and I-FABP expressing cells, respectively. L-FABP expression generally increased polyunsaturated fatty acids, primarily by increasing 20:4n-6 and 22:6n-3, while decreasing 18:1n-9 and 16:1n-7. I-FABP expression generally increased only 20:4n-6 proportions. Hence, expression of both I- and L-FABP differentially affected phospholipid mass, class composition, and acyl chain composition. Although both proteins enhanced phospholipid synthesis, the effect of L-FABP was much greater, consistent with previous work suggesting that these two FABP differentially affect lipid metabolism.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cholesterol / metabolism
  • Fatty Acid-Binding Protein 7
  • Fatty Acid-Binding Proteins
  • Fatty Acids / analysis
  • Fatty Acids / metabolism
  • Fatty Acids, Unsaturated / metabolism
  • Intestinal Mucosa / metabolism
  • L Cells
  • Liver / metabolism
  • Mice
  • Neoplasm Proteins*
  • Nerve Tissue Proteins*
  • Phospholipids / chemistry*
  • Phospholipids / metabolism*
  • Plasmalogens / metabolism
  • Recombinant Proteins / metabolism
  • Transfection

Substances

  • Carrier Proteins
  • Fabp1 protein, mouse
  • Fabp5 protein, mouse
  • Fabp7 protein, mouse
  • Fatty Acid-Binding Protein 7
  • Fatty Acid-Binding Proteins
  • Fatty Acids
  • Fatty Acids, Unsaturated
  • Neoplasm Proteins
  • Nerve Tissue Proteins
  • Phospholipids
  • Plasmalogens
  • Recombinant Proteins
  • Cholesterol