title: Reversible flow of cholesteryl ester between high-density lipoproteins and triacylglycerol-rich particles is modulated by the fatty acid composition and concentration of triacylglycerols.
abstract: We determined the influence of fasting (FAST) and feeding (FED) on cholesteryl ester (CE) flow between high-density lipoproteins (HDL) and plasma apoB-lipoprotein and triacylglycerol (TG)-rich emulsions (EM) prepared with TG-fatty acids (FAs). TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18% and 14%, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001) and a negative correlation from EM to HDL (r = -041, P = 0.0088). Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7%, 20.7%, and 20%, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7%, 51.2%, and 46.3%, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.
authors.affiliation: Universidade de São Paulo, SP, Brasil. pmcazita@hotmail.com
authors.forename: P M
authors.initials: PM
authors.lastname: Cazita
authors.forename: L N
authors.initials: LN
authors.lastname: Castilho
authors.forename: M D T
authors.initials: MD
authors.lastname: Carvalho
authors.forename: A C
authors.initials: AC
authors.lastname: Sesso
authors.forename: H C F
authors.initials: HC
authors.lastname: Oliveira
authors.forename: E C R
authors.initials: EC
authors.lastname: Quintão
mesh_terms: D002352:Carrier Proteins / Q000097:blood; D002788:Cholesterol Esters / Q000378:metabolism*; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism*; D005215:Fasting / Q000097:blood*; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008297:Male; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D002788:Cholesterol Esters; D004041:Dietary Fats; D008075:Lipoproteins, HDL; D014280:Triglycerides