scholarly journals Effects of APOC3 Heterozygous Deficiency on Plasma Lipid and Lipoprotein Metabolism

2019 ◽  
Vol 39 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Gissette Reyes-Soffer ◽  
Carol Sztalryd ◽  
Richard B. Horenstein ◽  
Stephen Holleran ◽  
Anastasiya Matveyenko ◽  
...  
2021 ◽  
Author(s):  
Gerald F Watts ◽  
Frederick J Raal ◽  
Dick C Chan

Angiopoietin-like protein 3 (ANGPTL3) is a key physiological regulator of plasma lipid and lipoprotein metabolism that involves the control of enzymes, lipoprotein and endothelial lipases. Inhibition of ANGPTL3 offers a new approach for correcting the health risks of dyslipidemia, including familial hypercholesterolemia, mixed hyperlipidemia, metabolic syndrome and/or severe hypertriglyceridemia. ANGPTL3 inhibition with nucleic acid-based antisense oligonucleotide and siRNA can correct dyslipidemia chiefly by reducing production and increasing catabolism of triglyceride-rich lipoprotein and LDL particles. Early clinical trials have demonstrated that these agents can safely and effectively lower plasma triglyceride and LDL-cholesterol levels by up to 70 and 50%, respectively. However, the long-term safety and cost–effectiveness of these agents await to be confirmed in an ongoing and future clinical trials.


2015 ◽  
Vol 22 (10) ◽  
pp. 1001-1011 ◽  
Author(s):  
Junji Kobayashi ◽  
Kazuya Miyashita ◽  
Katsuyuki Nakajima ◽  
Hiroshi Mabuchi

2020 ◽  
Vol 127 (11) ◽  
pp. 1347-1361 ◽  
Author(s):  
Xin Bi ◽  
Takashi Kuwano ◽  
Paul C. Lee ◽  
John S. Millar ◽  
Li Li ◽  
...  

Rationale: Single-nucleotide polymorphisms near the ILRUN (inflammation and lipid regulator with ubiquitin-associated–like and NBR1 [next to BRCA1 gene 1 protein]-like domains) gene are genome-wide significantly associated with plasma lipid traits and coronary artery disease (CAD), but the biological basis of this association is unknown. Objective: To investigate the role of ILRUN in plasma lipid and lipoprotein metabolism. Methods and Results: ILRUN encodes a protein that contains a ubiquitin-associated–like domain, suggesting that it may interact with ubiquitinylated proteins. We generated mice globally deficient for Ilrun and found they had significantly lower plasma cholesterol levels resulting from reduced liver lipoprotein production. Liver transcriptome analysis uncovered altered transcription of genes downstream of lipid-related transcription factors, particularly PPARα (peroxisome proliferator-activated receptor alpha), and livers from Ilrun -deficient mice had increased PPARα protein. Human ILRUN was shown to bind to ubiquitinylated proteins including PPARα, and the ubiquitin-associated–like domain of ILRUN was found to be required for its interaction with PPARα. Conclusions: These findings establish ILRUN as a novel regulator of lipid metabolism that promotes hepatic lipoprotein production. Our results also provide functional evidence that ILRUN may be the casual gene underlying the observed genetic associations with plasma lipids at 6p21 in human.


1996 ◽  
Vol 76 (6) ◽  
pp. 899-907 ◽  
Author(s):  
A Mazur ◽  
F Nassir ◽  
E Gueux ◽  
C Moundras ◽  
J Bellanger ◽  
...  

The present study examined the effects of Se, vitamin E and combined Se and vitamin E deficiencies in rats on plasma lipid, Lipoprotein and apolipoprotein (apo) concentrations. Deficiencies were induced by feeding rats the respective diets for 6 weeks. The study shows that Se deficiency results in increased concentrations of plasma cholesterol and apo E. Both could be explained by an increase in the HDL1 fraction. Vitamin E deficiency alone had no significant effect on plasma lipid, lipoprotein and apo concentrations. Se deficiency in combination with vitamin E deficiency leads to an increase in plasma LDL and apo B concentrations. These results point to the need for further investigations on the mechanism by which Se deficiency affects lipoprotein metabolism.


1992 ◽  
Vol 82 (6) ◽  
pp. 701-708 ◽  
Author(s):  
G. L. Warwick ◽  
C. J. Packard ◽  
L. Murray ◽  
D. Grierson ◽  
J. P. Stewart ◽  
...  

1. The effect of inhibiting the rate-limiting enzyme (3-hydroxy-3-methylglutaryl-CoA reductase, EC 1.1.1.88) in cholesterol synthesis on plasma lipid and lipoprotein concentrations was investigated in 16 patients with primary glomerular disease, heavy proteinuria, well-preserved renal function and hypercholesterolaemia. 2. Detailed studies of low-density lipoprotein metabolism were performed on eight patients before and after 12 weeks of simvastatin therapy. Radioiodinated tracers were used to quantify the fractional catabolic rate of low-density lipoprotein by apolipoprotein B/E receptors and alternative pathways. 3. Simvastatin produced consistent reductions in total plasma cholesterol concentration (median 36.9%), plasma low-density lipoprotein-cholesterol concentration (43.6%) and apolipoprotein B pool size (29.9%). 4. In contrast, the changes in kinetic parameters of low-density lipoprotein metabolism showed no clear pattern. Although an increase in the receptor-mediated catabolism of low-density lipoprotein was demonstrated in five patients, no change or a slight decrease was seen in three patients. Production rates were not significantly altered, although there was a slight decrease in the median value (from 12.4 to 9.7 mg day−1 kg−1). Plasma lathosterol concentration was reduced in all eight patients (range 34–71%), indirectly confirming significant inhibition of cholesterol synthesis. 5. These results suggest that, as in patients with primary moderate hyperlipidaemia, the significant cholesterol-lowering effect of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors in the nephrotic syndrome is accompanied by variable changes in lipoprotein metabolism. The reasons for this heterogeneous response are unclear. This reflects our limited understanding of the metabolic basis of nephrotic hyperlipidaemia and the relationship between hepatic sterol synthesis and plasma lipoprotein kinetics.


2010 ◽  
Vol 95 (7) ◽  
pp. 3377-3384 ◽  
Author(s):  
Faidon Magkos ◽  
Elisa Fabbrini ◽  
B. Selma Mohammed ◽  
Bruce W. Patterson ◽  
Samuel Klein ◽  
...  

Context: Sex differences in lipid metabolism result in a less proatherogenic plasma lipid profile in premenopausal women than men. The mechanisms responsible for this are unclear but are thought to be related to differences in the sex hormone milieu in men and women. Objective: Our objective was to evaluate the effect of endogenous sex hormones on very-low-density lipoprotein (VLDL) triglyceride (TG) and apolipoprotein B-100 (apoB-100) metabolism. Experimental Design and Main Outcome Measures: We measured basal VLDL-TG and VLDL-apoB-100 concentrations and kinetics by using stable isotope-labeled tracers. Setting and Participants: Eight premenopausal women [age, 43 ± 8 yr; body mass index (BMI), 35 ± 4 kg/m2; mean ± sd], eight postmenopausal women (age, 55 ± 4 yr; BMI, 34 ± 4 kg/m2), and eight men (age, 41 ± 13 yr; BMI, 34 ± 4 kg/m2) were studied at Washington University School of Medicine, St. Louis, MO. Results: VLDL-TG secretion rate was approximately double (P < 0.05) in postmenopausal women and men compared with premenopausal women but not different in postmenopausal women and men. The secretion rate of VLDL-apoB-100 was not different in pre- and postmenopausal women but was greater (P < 0.05) in men than in women. Conclusions: Endogenous ovarian sex steroids are responsible for sexual dimorphism in VLDL-TG secretion, whereas VLDL-apoB-100 secretion is not regulated by female reproductive hormones.


2014 ◽  
Vol 7 ◽  
pp. LPI.S14798
Author(s):  
Omar F. Khabour ◽  
Mahmoud A. Alomari ◽  
Karem H. Alzoubi ◽  
Mohammad Y. Gharaibeh ◽  
Farah H. Alhashimi

The human hepatic lipase ( LIPC) gene encodes hepatic lipase, an enzyme involved in lipoprotein metabolism and regulation. Therefore, variants in LIPC gene may influence plasma lipoprotein levels. In this study, the association of LIPC C-514T and G-250A polymorphisms with plasma lipid profiles in 348 young Jordanians was investigated. Genotyping of C-514T and G-250A was performed by polymerase chain reaction and subsequent digestion with DraI and NiaIII restriction enzymes, respectively, while Roche analyzer was used to determine plasma total cholesterol, triglycerides, low-and high-density lipoprotein. The G-250 and C-514 alleles were most abundant in Jordanians with 79 and 80% frequencies, respectively. Additionally, no difference was found in the lipid–lipoprotein profile between the different genotype groups of C-514T or G-250A polymorphisms, even when males and females were examined separately ( P ≫ 0.05). In young Jordanian adults, the examined LIPC polymorphisms seem to play a limited role in determining the lipid profile.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
André J Tremblay ◽  
Benoit Lamarche ◽  
Valerie Guay ◽  
Valery Lemelin ◽  
Patrick Couture

Dietary saturated fat (SFA) and trans fatty acids (TFA) have been linked to an increased risk of cardiovascular disease mainly by increasing plasma LDL-C levels. The modulation of cholesterol and fatty acids homeostasis by SFA and TFA is thought to be mediated by changes in expression of key intestinal genes involved in lipid and lipoprotein metabolism. However, the short-term impact of dietary fat intake on expression of these genes has not been fully investigated. To test whether short-term changes in SFA and TFA intake affects expression of key intestinal genes involved in lipid and lipoprotein metabolism, we conducted a randomized, double-blind, cross-over study using an intensive dietary modification in 12 nonobese healthy men with normal plasma lipid profile. Participants were subjected to 2 isocaloric 3-day diets: 1) high-fat diet (37% energy from fat, 15% from SFA, 3.5% from TFA and 50% energy from carbohydrate) and 2) low-fat diet (25% energy from fat, 6% from SFA, 0% from TFA and 62% energy from carbohydrate) in random order, each separated by a two-week washout period. Fasting plasma lipid levels were determined and expression of key genes involved in lipid and lipoprotein metabolism was compared by real-time PCR quantification in duodenal biopsy specimens obtained in the fasted state after 3 days of feeding on each diet. Following the 3-day high-fat diet, plasma-C (+7.4%, P=0.02), LDL-C (+16.9%, P=0.005) and HDL-C (+9.3%, P=0.002) levels were significantly increased as compared to low-fat diet. Plasma triglycerides (-31.7%, P=0.001) and apolipoprotein B-48 (-39.6%, P=0.003) levels were significantly decreased after the high-fat diet relative to the low-fat diet. The high-fat diet also resulted in significant increases in intestinal mRNA expression levels of SREBP-2, HNF-4α, PPAR-α, PPAR-γ, NPC1L1, ABCG8, FABP-2, ACAC-α, SCD-1, ELOVL5, DGAT-2, apolipoprotein B, MTTP, SAR1β and LDL receptor. These findings suggest that short-term exposure to a high-SFA and TFA diet upregulates the expression of key genes involved in lipid and lipoprotein metabolism at the enterocyte level.


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