|
Advertisement | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Journal of Lipid Research, Vol. 47, 1212-1218, June 2006 Apolipoprotein C-III isoforms: kinetics and relative implication in lipid metabolism
* Institute on Nutraceuticals and Functional Foods, Laval University, Québec, Canada Published, JLR Papers in Press, February 22, 2006.
1 To whom correspondence should be addressed. e-mail: benoit.lamarche{at}inaf.ulaval.ca Apolipoprotein C-III (apoC-III) production rate (PR) is strongly correlated with plasma triglyceride (TG) levels. ApoC-III exists in three different isoforms, according to the sialylation degree of the protein. We investigated the kinetics and respective role of each apoC-III isoform in modulating intravascular lipid/lipoprotein metabolism. ApoC-III kinetics were measured in a sample of 18 healthy men [mean age (±SD) 42.1 ± 9.5 years, body mass index 29.8 ± 4.6 kg/m2] using a primed-constant infusion of L-(5,5,5-D3) leucine for 12 h. Mono-sialylated and di-sialylated apoC-III (apo-CIII1 and apoC-III2) exhibited similar PRs (means ± SD, 1.22 ± 0.49 mg/kg/day vs. 1.15 ± 0.59 mg/kg/day, respectively) and similar fractional catabolic rates (FCRs) (0.51 ± 0.13 pool/day vs. 0.61 ± 0.24 pool/day, respectively). Nonsialylated apoC-III (apoC-III0) had an 80% lower PR (0.25 ± 0.12 mg/kg/day) and a 60% lower FCR (0.21 ± 0.07 pool/day) (P < 0.0001 for comparison with CIII1 and CIII2 isoforms). The PRs of apoC-III1 and apoC-III2 were more strongly correlated with plasma TG levels (r > 0.8, P < 0.0001) than was apoC-III0 PR (r = 0.54, P < 0.05). Finally, the PR of apoC-III2 was strongly correlated with the proportion of LDL <255 Å (r = 0.72, P = 0.002). These results suggest that all apoC-III isoforms, especially the predominant CIII1 and CIII2 isoforms, contribute to hypertriglyceridemia and that apoC-III2 may play a significant role in the expression of the small, dense LDL phenotype.
Abbreviations: apoC-III, apolipoprotein C-III; BMI, body mass index; FCR, fractional catabolic rate; HDL-C, HDL-cholesterol; LPL, lipoprotein lipase; PR, production rate; PS, pool size; TG, triglyceride; TRL, triglyceride-rich lipoprotein Supplementary key words VLDL metabolism metabolic syndrome triglycerides LDL particle size sialylation
This article has been cited by other articles:
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Advertisement | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||