| 1. |
- Adiels, Martin, 1976, et al.
(författare)
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Overproduction of very low-density lipoproteins is the hallmark of the dyslipidemia in the metabolic syndrome.
- 2008
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636 .- 1079-5642. ; 28:7, s. 1225-36
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Forskningsöversikt (refereegranskat)abstract
- Insulin resistance is a key feature of the metabolic syndrome and often progresses to type 2 diabetes. Both insulin resistance and type 2 diabetes are characterized by dyslipidemia, which is an important and common risk factor for cardiovascular disease. Diabetic dyslipidemia is a cluster of potentially atherogenic lipid and lipoprotein abnormalities that are metabolically interrelated. Recent evidence suggests that a fundamental defect is an overproduction of large very low-density lipoprotein (VLDL) particles, which initiates a sequence of lipoprotein changes, resulting in higher levels of remnant particles, smaller LDL, and lower levels of high-density liporotein (HDL) cholesterol. These atherogenic lipid abnormalities precede the diagnosis of type 2 diabetes by several years, and it is thus important to elucidate the mechanisms involved in the overproduction of large VLDL particles. Here, we review the pathophysiology of VLDL biosynthesis and metabolism in the metabolic syndrome. We also review recent research investigating the relation between hepatic accumulation of lipids and insulin resistance, and sources of fatty acids for liver fat and VLDL biosynthesis. Finally, we briefly discuss current treatments for lipid management of dyslipidemia and potential future therapeutic targets.
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| 2. |
- Adiels, Martin, 1976, et al.
(författare)
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Overproduction of VLDL1 driven by hyperglycemia is a dominant feature of diabetic dyslipidemia
- 2005
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Ingår i: Arterioscler Thromb Vasc Biol. - 1524-4636 .- 1079-5642. ; 25:8, s. 1697-703
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We sought to compare the synthesis and metabolism of VLDL1 and VLDL2 in patients with type 2 diabetes mellitus (DM2) and nondiabetic subjects. METHODS AND RESULTS: We used a novel multicompartmental model to simultaneously determine the kinetics of apolipoprotein (apo) B and triglyceride (TG) in VLDL1 and VLDL2 after a bolus injection of [2H3]leucine and [2H5]glycerol and to follow the catabolism and transfer of the lipoprotein particles. Our results show that the overproduction of VLDL particles in DM2 is explained by enhanced secretion of VLDL1 apoB and TG. Direct production of VLDL2 apoB and TG was not influenced by diabetes per se. The production rates of VLDL1 apoB and TG were closely related, as were the corresponding pool sizes. VLDL1 and VLDL2 compositions did not differ in subjects with DM2 and controls, and the TG to apoB ratio of newly synthesized particles was very similar in the 2 groups. Plasma glucose, insulin, and free fatty acids together explained 55% of the variation in VLDL1 TG production rate. CONCLUSIONS: Insulin resistance and DM2 are associated with excess hepatic production of VLDL1 particles similar in size and composition to those in nondiabetic subjects. We propose that hyperglycemia is the driving force that aggravates overproduction of VLDL1 in DM2.
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| 3. |
- Adlanmerini, M., et al.
(författare)
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Mutation of Arginine 264 on ER alpha (Estrogen Receptor Alpha) Selectively Abrogates the Rapid Signaling of Estradiol in the Endothelium Without Altering Fertility
- 2020
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Ingår i: Arteriosclerosis, Thrombosis, and Vascular Biology. - : Ovid Technologies (Wolters Kluwer Health). - 1079-5642 .- 1524-4636. ; 40:9, s. 2143-2158
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Tidskriftsartikel (refereegranskat)abstract
- Objective: ER alpha (estrogen receptor alpha) exerts nuclear genomic actions and also rapid membrane-initiated steroid signaling. The mutation of the cysteine 451 into alanine in vivo has recently revealed the key role of this ER alpha palmitoylation site on some vasculoprotective actions of 17 beta-estradiol (E2) and fertility. Here, we studied the in vivo role of the arginine 260 of ER alpha which has also been described to be involved in its E2-induced rapid signaling with PI-3K (phosphoinositide 3-kinase) as well as G protein in cultured cell lines. Approach and Results: We generated a mouse model harboring a point mutation of the murine counterpart of this arginine into alanine (R264A-ER alpha). In contrast to theC451A-ER alpha, theR264A-ER alpha females are fertile with standard hormonal serum levels and normal control of hypothalamus-pituitary ovarian axis. Although R264A-ER alpha protein abundance was normal, the well-described membrane ER alpha-dependent actions of estradiol, such as the rapid dilation of mesenteric arteries and the acceleration of endothelial repair of carotid, were abrogated inR264A-ER alpha mice. In striking contrast, E2-regulated gene expression was highly preserved in the uterus and the aorta, revealing intact nuclear/genomic actions in response to E2. Consistently, 2 recognized nuclear ER alpha-dependent actions of E2, namely atheroma prevention and flow-mediated arterial remodeling were totally preserved. Conclusions: These data underline the exquisite role of arginine 264 of ER alpha for endothelial membrane-initiated steroid signaling effects of E2 but not for nuclear/genomic actions. This provides the first model of fertile mouse with no overt endocrine abnormalities with specific loss-of-function of rapid ER alpha signaling in vascular functions.
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| 4. |
- Akinkuolie, Akintunde O, et al.
(författare)
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Group IIA Secretory Phospholipase A2, Vascular Inflammation, and Incident Cardiovascular Disease.
- 2019
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 39:6, s. 1182-1190
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Tidskriftsartikel (refereegranskat)abstract
- Objective- Inflammation is a causal risk factor for cardiovascular disease (CVD). sPLA2-IIA (group IIA secretory phospholipase A2) plays an integral role in regulating vascular inflammation. Although studies investigated sPLA2-IIA in secondary prevention, we prospectively evaluated sPLA2-IIA mass and genetic variants with CVD events in a primary prevention population with chronic inflammation. Approach and Results- The JUPITER trial (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin) randomized participants with LDL (low-density lipoprotein) <130 mg/dL and hsCRP (high-sensitivity C-reactive protein) ≥2 mg/L to high-intensity rosuvastatin versus placebo. Baseline and 1-year plasma sPLA2-IIA mass was measured (N=11269 baseline; N=9620 1 year). We also identified genetic variants influencing sPLA2-IIA using genome-wide association and examined them with CVD. Three hundred thirteen incident CVD events occurred during follow-up. Baseline sPLA2-IIA mass (median, 25th-75th percentile: 3.81, 2.49-6.03 ng/mL) was associated with increased risk of CVD: risk factor-adjusted hazard ratio (95% CI; P) per SD increment: 1.22 (1.08-1.38; P=0.002). This remained significant (1.18; 1.04-1.35; P=0.01) after incrementally adjusting for hsCRP. Similar estimates were observed in rosuvastatin and placebo groups ( P treatment interaction>0.05). The rs11573156C variant in PLA2G2A (encoding sPLA2-IIA) had the strongest effect on sPLA2-II: median (25th-75th percentile, ng/mL) for CC and GG genotypes: 2.79 (1.97-4.01) and 7.38 (5.38-10.19), respectively; and had nonsignificant trend for higher CVD risk (hazard ratio, 1.11; 95% CI, 0.89-1.38; P=0.34). Conclusions- In the JUPITER population recruited on chronic inflammation, sPLA2-IIA mass was associated with CVD risk relating to vascular inflammation not fully reflected by hsCRP. Additional studies, including larger functional genetic and clinical studies, are needed to determine whether sPLA2-IIA may be a potential pharmacological target for primary prevention of CVD. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT00239681.
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| 5. |
- Asp, Lennart, 1965, et al.
(författare)
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Role of ADP ribosylation factor 1 in the assembly and secretion of ApoB-100-containing lipoproteins
- 2005
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Ingår i: Arterioscler Thromb Vasc Biol. - 1524-4636. ; 25:3, s. 566-70
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We investigated the role of ADP ribosylation factor 1 (ARF1) in the assembly of very-low-density lipoproteins (VLDLs). METHODS AND RESULTS: The dominant-negative ARF1 mutant, T31N, decreased the assembly of apoB-100 VLDL 1 (Svedberg floatation units [Sf] 60 to 400) by 80%. The decrease coincided with loss of coatamer I (COPI) from the Golgi apparatus and inhibition of anterograde transport, as demonstrated by time-lapse studies of the vesicular stomatitis virus G protein. The VLDL 1 assembly was also completely inhibited at 15 degrees C. Thus, the antegrade transport is essential for the assembly of VLDL 1. Intracellular localization of N-acetylgalactosaminyl transferase 2 indicated that the Golgi apparatus was at least partly intact when the VLDL assembly was inhibited. Transient transfection with phospholipase D 1 increased the assembly of VLDL 1 and VLDL 2 (Sf 20 to 60). Overexpression of ARF1 in stably transfected McA-RH7777 cells increased the secretion of VLDL 2 but not of VLDL 1, which was dependent on the availability of oleic acid. Secretion of VLDL 1 increased with increasing amounts of oleic acid, and VLDL 2 secretion decreased simultaneously. CONCLUSIONS: Overexpression of ARF1 increased the assembly of VLDL 2 but not of VLDL 1, whose production was dependent on both anterograde transport and the availability of fatty acids.
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| 6. |
- Björkman, Jan-Arne, et al.
(författare)
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Cardiac sympathetic nerve stimulation triggers coronary t-PA release.
- 2003
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 23:6, s. 1091-7
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study was undertaken to determine whether stimulation of sympathetic cardiac nerves induces release of the thrombolytic enzyme tissue-type plasminogen activator (t-PA) in the coronary vascular bed. METHODS AND RESULTS: Anesthetized pigs were studied in an open chest model. Bilateral vagotomy was performed, and sympathetic cardiac nerves were activated by electrical stimulation (1 and 8 Hz). To evaluate possible mediating effects of increased heart rate and enhanced local blood flow, tachycardia was induced by pacing and hyperemia by local infusion of sodium nitroprusside and clevedipine. Furthermore, to study the effects of alpha- and beta-adrenergic receptor stimulation, phenylephrine and isoprenaline were infused locally. In response to low- and high-frequency sympathetic stimulation, mean coronary net release of total t-PA increased approximately 6- and 25-fold, respectively. Active t-PA showed a similar response pattern. Neither tachycardia nor coronary hyperemia stimulated t-PA release. In contrast, beta-adrenergic stimulation by isoprenaline induced an approximately 6-fold increase in coronary t-PA release, whereas no significant change in release rates occurred in response to alpha-adrenergic stimulation by phenylephrine. CONCLUSIONS: Stimulation of cardiac sympathetic nerves induces a marked coronary release of t-PA, and part of this response may be mediated through stimulation of beta-adrenergic receptors.
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| 7. |
- Borén, Jan, 1963, et al.
(författare)
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Kinetic and Related Determinants of Plasma Triglyceride Concentration in Abdominal Obesity Multicenter Tracer Kinetic Study
- 2015
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Ingår i: Arteriosclerosis Thrombosis and Vascular Biology. - : Ovid Technologies (Wolters Kluwer Health). - 1079-5642 .- 1524-4636. ; 35:10, s. 2218-2224
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Patients with obesity and diabetes mellitus have increased risk of cardiovascular disease. A major cause is an atherogenic dyslipidemia related primarily to elevated plasma concentrations of triglyceride-rich lipoproteins. The aim of this study was to clarify determinants of plasma triglyceride concentration. We focused on factors that predict the kinetics of very-low density lipoprotein 1 (VLDL1) triglycerides. Approach and Results A multicenter study using dual stable isotopes (deuterated leucine and glycerol) and multicompartmental modeling was performed to elucidate the kinetics of triglycerides and apoB in VLDL1 in 46 subjects with abdominal obesity and additional cardiometabolic risk factors. Results showed that plasma triglyceride concentrations were dependent on both the secretion rate (r=0.44, P<0.01; r=0.45, P<0.01) and fractional catabolism (r=0.49, P<0.001; r=0.55, P<0.001) of VLDL1-triglycerides and VLDL1-apoB. Liver fat mass was independently and directly associated with secretion rates of VLDL1-triglycerides (r=0.56, P<0.001) and VLDL1-apoB (r=0.53, P<0.001). Plasma apoC-III concentration was independently and inversely associated with the fractional catabolisms of VLDL1-triglycerides (r=0.48, P<0.001) and VLDL1-apoB (r=0.51, P<0.001). Conclusions Plasma triglyceride concentrations in abdominal obesity are determined by the kinetics of VLDL1 subspecies, catabolism being mainly dependent on apoC-III concentration and secretion on liver fat content. Reduction in liver fat and targeting apoC-III may be an effective approach for correcting triglyceride metabolism atherogenic dyslipidemia in obesity.
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| 8. |
- Boström, Pontus, 1982, et al.
(författare)
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Cytosolic lipid droplets increase in size by microtubule-dependent complex formation
- 2005
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Ingår i: Arterioscler Thromb Vasc Biol. - 1524-4636. ; 25:9, s. 1945-51
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Adipocyte differentiation-related protein (ADRP)-containing lipid droplets have an essential role in the development of insulin resistance and atherosclerosis. Such droplets form in a cell-free system with a diameter of 0.1 to 0.4 microm, while the droplets present in cells vary in size, from small to very large, suggesting that the droplets can increase in size after being assembled. We have addressed this possibility. METHODS AND RESULTS: Experiments in NIH 3T3 cells demonstrated that the lipid droplets could increase in size independently of triglyceride biosynthesis. NIH 3T3 cells were either microinjected with ADRP-GFP (green fluorescent protein) or stained with Nile Red and followed by confocal microscopy and time-lapse recordings. The results showed that lipid droplets formed complexes with each other, with a volume equal to the sum of the merging particles. The formation of complexes could be inhibited by the nocodazole-induced depolymerization of the microtubules; thus, the process is dependent on microtubules. The presence of dynein on ADRP-containing droplets supports a role for this motor protein. CONCLUSIONS: Lipid droplets can grow after they have been assembled. This increase in size is independent of triglyceride biosynthesis and involves formation of complexes, which requires intact microtubules.
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| 9. |
- Boström, Pontus, 1982, et al.
(författare)
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Hypoxia converts human macrophages into triglyceride-loaded foam cells.
- 2006
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 26:8, s. 1871-6
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Atherosclerotic lesions have regions that are hypoxic. Because the lesion contains macrophages that are loaded with lipid, we investigated whether hypoxia can influence the accumulation of lipids in these cells. METHODS AND RESULTS: Exposure of human macrophages to hypoxia for 24 hours resulted in an increased formation of cytosolic lipid droplets and an increased accumulation of triglycerides. Exposure of the macrophages to oxidized low-density lipoprotein (oxLDL) increased the accumulation of cytosolic lipid droplets because of an increase in cellular cholesterol esters. The accumulation of lipid droplets in oxLDL-treated cells was further increased after hypoxia, caused by an increased level of triglycerides. Expression analyses combined with immunoblot or RT-PCR demonstrated that hypoxia increased the expression of several genes that could promote the accumulation of lipid droplets. Hypoxia increased the mRNA and protein levels of adipocyte differentiation-related protein (ADRP). It is well known that an increased expression of ADRP increases the formation of lipid droplets. Hypoxia decreased the expression of enzymes involved in beta-oxidation (acyl-coenzyme A synthetase and acyl-coenzyme A dehydrogenase) and increased the expression of stearoyl-coenzyme A desaturase, an important enzyme in the fatty acid biosynthesis. Moreover, exposure to hypoxia decreased the rate of beta-oxidation, whereas the accumulation of triglycerides increased. CONCLUSIONS: The results demonstrate that exposure of human macrophages to hypoxia causes an accumulation of triglyceride-containing cytosolic lipid droplets. This indicates that the hypoxia present in atherosclerotic lesions can contribute to the formation of the lipid-loaded macrophages that characterize the lesion and to the accumulation of triglycerides in such lesions.
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| 10. |
- Bramsved, Rebecka, 1982, et al.
(författare)
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Birth Weight, Childhood and Young Adult Overweight, and the Risk of Coronary Heart Disease in Men.
- 2024
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 44:1, s. 314-321
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Tidskriftsartikel (refereegranskat)abstract
- Low birth weight is a known risk factor for adult coronary heart disease (CHD), but the additional effect of weight development during childhood and early adult life has not been studied.We included 35659 men born 1945 to 1961 from the population-based BMI Epidemiology Study Gothenburg, with data available on birthweight, BMI in childhood (8 years), and BMI in young adulthood (20 years). Information on CHD diagnoses was retrieved from national registers. We used Cox proportional hazards regression to estimate hazard ratios and 95% CIs for the risk of early and late CHD (before and after 58.4 years of age, respectively).During follow-up, a total of 3380 cases of CHD (fatal and nonfatal) were registered. Birth weight was inversely associated with the risk of both early (hazard ratio, 0.88 per SD increase [95% CI, 0.84-0.92]) and late (hazard ratio, 0.94 per SD increase [95% CI, 0.90-0.98]) CHD, independently of BMI at 8 years and BMI change during puberty. In a model including birth weight (below or above the median) together with overweight at 8 and 20 years, only birth weight and young adult overweight, but not overweight in childhood, were significantly associated with the risk of CHD. A birth weight below the median, followed by overweight at 20 years of age was associated with a more than doubled risk of early CHD (hazard ratio, 2.29 [95% CI, 1.86-2.81]), compared with the reference (birth weight above the median and normal weight at 20 years of age). This excess risk was even more pronounced for a birthweight below 2.5 kg.We demonstrate that low birth weight and young adult overweight are important developmental markers of risk for adult CHD. These findings motivate a life course perspective for prevention and risk assessment of adult CHD.
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