Biomaterial Database

The effects of n-3 fatty acids on the secretion of carboxyl-terminally truncated forms of human apoprotein B. 1994

H Wang, and Z Yao, and E A Fisher

Department of Biochemistry, Medical College of Pennsylvania, Philadelphia 19129.

We have previously reported that in primary rat hepatocytes, n-3 fatty acid (either eicosapentaenoic or docosahexaenoic) stimulates intracellular degradation of apoprotein B100 (apoB100) and apoB48 (Wang, H., Chen, X., and Fisher, E.A. (1993) J. Clin. Invest. 91, 1380-1389). There was a greater effect on apoB100 than on apoB48. Rat hepatoma (McArdle RH-7777) cell lines expressing carboxyl-truncated human apoB species apoB42, apoB28, and apoB18 were used to explore the relationship between the effects of n-3 fatty acids and apoB lipidation. After density gradient separation of conditioned media, apoB42 was found at d < 1.21 (lipid-rich), apoB18 at d > 1.21 (lipid-poor), and apoB28 in both fractions. After incubation with albumin complexed with eicosapentaenoic or docosahexaenoic acids, relative to oleic acid, the secretion of newly synthesized apoB was 35% (apoB42), 54% (apoB28), and 96% (apoB18). Further analysis of the apoB28 data showed decreased secretion of only lipid-rich (d < 1.21) apoB28. Pulse-chase studies indicated that with n-3 fatty acid there was increased intracellular degradation of apoB42 concomitant with its decreased secretion. We conclude that the ability of the n-3 fatty acids to promote apoB degradation correlated with the degree of lipidation of the secreted apoB, consistent with specialized intracellular pathways for the degradation of apoB and the assembly of buoyant, apoB-containing lipoproteins.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008114	Liver Neoplasms, Experimental	Experimentally induced tumors of the LIVER.	Hepatoma, Experimental,Hepatoma, Morris,Hepatoma, Novikoff,Experimental Hepatoma,Experimental Hepatomas,Experimental Liver Neoplasms,Hepatomas, Experimental,Neoplasms, Experimental Liver,Experimental Liver Neoplasm,Liver Neoplasm, Experimental,Morris Hepatoma,Novikoff Hepatoma
D008715	Methionine	A sulfur-containing essential L-amino acid that is important in many body functions.	L-Methionine,Liquimeth,Methionine, L-Isomer,Pedameth,L-Isomer Methionine,Methionine, L Isomer
D009829	Oleic Acids	A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.	Octadecenoic Acids,Acids, Octadecenoic,Acids, Oleic
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D004281	Docosahexaenoic Acids	C22-unsaturated fatty acids found predominantly in FISH OILS.	Docosahexaenoate,Docosahexaenoic Acid,Docosahexenoic Acids,Docosahexaenoic Acid (All-Z Isomer),Docosahexaenoic Acid Dimer (All-Z Isomer),Docosahexaenoic Acid, 3,6,9,12,15,18-Isomer,Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer),Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer), Cerium Salt,Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer), Cesium Salt,Docosahexaenoic Acid, 4,7,10,13,16,19-(All-Z-Isomer), Potassium Salt,Docosahexaenoic Acid, 4,7,10,13,16,19-(Z,Z,Z,Z,Z,E-Isomer),Docosahexaenoic Acid, 4,7,10,13,16,19-Isomer,Docosahexaenoic Acid, 4,7,10,13,16,19-Isomer, Sodium Salt,Docosahexaenoic Acid, Sodium Salt,Acid, Docosahexaenoic,Acids, Docosahexaenoic,Acids, Docosahexenoic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001055	Apolipoproteins B	Major structural proteins of triacylglycerol-rich LIPOPROTEINS. There are two forms, apolipoprotein B-100 and apolipoprotein B-48, both derived from a single gene. ApoB-100 expressed in the liver is found in low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). ApoB-48 expressed in the intestine is found in CHYLOMICRONS. They are important in the biosynthesis, transport, and metabolism of triacylglycerol-rich lipoproteins. Plasma Apo-B levels are high in atherosclerotic patients but non-detectable in ABETALIPOPROTEINEMIA.	Apo-B,Apo B,ApoB,Apoprotein (B),Apoproteins B