Per- and polyfluoroalkyl substances (PFAS) are widely used and persistent chemicals, leading to ubiquitous exposure. Although high PFAS levels have been associated with an adverse cardiovascular... Show morePer- and polyfluoroalkyl substances (PFAS) are widely used and persistent chemicals, leading to ubiquitous exposure. Although high PFAS levels have been associated with an adverse cardiovascular risk profile, the distribution of levels and relations with cardio-metabolic risk markers in the general population have not been fully characterized. We assessed the association between blood levels of perfluorooctaneic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS) and a range of lipoproteins and metabolites as well as clinical lipid measurements. We used data from participants of the Netherlands Epidemiology of Obesity study (NEO) (n = 584) and the Rhineland Study (n = 1962), jointly spanning an age range of 30 to 89 years. PFAS were measured with the Metabolon HD4 platform, and lipoprotein and metabolite profiles were measured using Nightingale's nuclear magnetic resonance-spectroscopy platform, and mainly comprised lipoprotein markers. Using linear regression analyses, we quantified age-, sex-, and education-adjusted associations of PFOA, PFOS, and PFHxS with clinical lipid measurements and 224 lipoproteins and metabolites. Higher levels of PFAS, particularly PFOS and PFHxS, were associated with higher concentrations of total lipid, cholesterol and phospholipid content in most HDL, IDL, LDL, and VLDL subclasses. The effect sizes were age-dependent for the majority of the associations, with the deleterious effects of PFAS being generally stronger in people below compared to those above median age. Our observation that in the general population even low PFAS concentrations are associated with an unfavorable lipid profile, calls for further critical regulation of PFAS substances. Show less
Cardiovascular diseases are the leading cause of death worldwide, with atherosclerosis as most common underlying pathology. Atherosclerosis is characterized by arterial narrowing due to cholesterol... Show moreCardiovascular diseases are the leading cause of death worldwide, with atherosclerosis as most common underlying pathology. Atherosclerosis is characterized by arterial narrowing due to cholesterol and lipid accumulation. Despite available effective cholesterol lowering medication, considerable risk for recurrent vascular events remains. This residual risk is at least in part explained by high blood lipid levels. The research described in this thesis revealed novel therapeutic strategies that improve lipid metabolism and reduce atherosclerosis development in mice. Inhibition of the endocannabinoid system was found to be an effective strategy, as well as concomitant activation of two incretin hormone receptors, namely those for GIP and GLP1. For combined GIP/GLP1 receptor agonism we additionally showed strongly attenuated hepatic steatosis. We were also able to identify additional targets to attenuate hyperlipidemia by studying the mechanisms underlying the strong day-night rhythm of brown adipose tissue, which is a lipid combusting tissue. In this thesis, I also stress the importance of the choice in animal model when studying lipid-modifying interventions, and describe the development of the software tool RandoMice which can be used to improve the quality of preclinical studies by creating well-balanced experimental groups. Show less
Cardiovascular diseases are still a major concern for the global health. The main underlying pathology of this disease is atherosclerosis which is characterized by the accumulation of lipids and... Show moreCardiovascular diseases are still a major concern for the global health. The main underlying pathology of this disease is atherosclerosis which is characterized by the accumulation of lipids and immune cells in the arterial wall leading to a chronic local inflammation and lesion formation. In this thesis, we aimed to (1) validate the use of zebrafish in cholesterol metabolism and atherosclerosis research, (2) study the role of certain classes of scavenger receptors in lipoprotein uptake and cholesterol-based functions, and (3) validated two immune-based potential targets for atherosclerosis. Show less
Ying, Z.X.; Eenige, R. van; Beerepoot, R.; Boon, M.R.; Kloosterhuis, N.J.; Sluis, B. van de; ... ; Kooijman, S. 2022
Activation of brown adipose tissue (BAT) with the 133-adrenergic receptor agonist CL316,243 protects mice from atherosclerosis development, and the presence of metabolically active BAT is... Show moreActivation of brown adipose tissue (BAT) with the 133-adrenergic receptor agonist CL316,243 protects mice from atherosclerosis development, and the presence of metabolically active BAT is associated with cardiometabolic health in humans. In contrast, exposure to cold or treatment with the clinically used 133-adrenergic receptor agonist mirabegron to activate BAT exacerbates atherosclerosis in apolipoprotein E (ApoE)-and low-density lipoprotein receptor (LDLR)-deficient mice, both lacking a functional ApoE-LDLR pathway crucial for lipopro-tein remnant clearance. We, therefore, investigated the effects of mirabegron treatment on dyslipidemia and atherosclerosis development in APOE*3-Leiden.CETP mice, a humanized lipoprotein metabolism model with a functional ApoE-LDLR clearance pathway. Mirabegron activated BAT and induced white adipose tissue (WAT) browning, accompanied by selectively increased fat oxidation and attenuated fat mass gain. Mirabegron increased the uptake of fatty acids derived from triglyceride (TG)-rich lipoproteins by BAT and WAT, which was coupled to increased hepatic uptake of the generated cholesterol-enriched core remnants. Mirabegron also promoted hepatic very low-density lipoprotein (VLDL) production, likely due to an increased flux of fatty acids from WAT to the liver, and resulted in transient elevation in plasma TG levels followed by a substantial decrease in plasma TGs. These effects led to a trend toward lower plasma cholesterol levels and reduced atherosclerosis. We conclude that BAT activation by mirabegron leads to substantial metabolic benefits in APOE*3-Leiden.CETP mice, and mirabegron treatment is certainly not atherogenic. These data underscore the importance of the choice of experimental models when investigating the effect of BAT activation on lipoprotein metabolism and atherosclerosis. Show less
Maarse, B.C.E.; Loh, N.Y.; Karpe, F.; Rosendaal, F.R.; Heemst, D. van; Mook-Kanamori, D.O.; ... ; Noordam, R. 2020
Background and aims: Outdoor temperature and bright sunlight may directly and/or indirectly modulate systemic metabolism. We assessed the associations between outdoor temperature and bright... Show moreBackground and aims: Outdoor temperature and bright sunlight may directly and/or indirectly modulate systemic metabolism. We assessed the associations between outdoor temperature and bright sunlight duration with metabolomics.Methods and results: Cross-sectional analyses were undertaken in non-diabetic individuals from the Oxford BioBank (OBB; N = 6368; mean age 47.0 years, males 44%) and the Netherlands Epidemiology of Obesity (NEO; N = 5916; mean age 55.6 years, males 43%) study. Data on mean outdoor bright sunlight and temperature were collected from local weather stations in the week prior to blood sampling. Fasting serum levels of 148 metabolites, including 14 lipoprotein subclasses, were measured using NMR spectroscopy. Linear regression analyses were performed to assess the associations between mean outdoor temperature and bright sunlight duration with metabolomics adjusted for age, sex, body mass index, season and either outdoor temperature or bright sunlight. A higher mean outdoor temperature was associated with increased serum concentrations of lipoprotein (sub)particles (beta (SE) = 0.064 (0.018) SD per 5 degrees C, p = 5.03e(-4)) and certain amino acids such as phenylalanine (0.066 (0.016) SD, p = 6.44e(-05)) and leucine (0.111 (0.018) SD, p = 1.25e(-09)). In contrast, longer duration of bright sunlight was specifically associated with lower concentrations of very low-density lipoprotein (sub)particles (e.g., VLDL cholesterol (-0.024 (0.005) SD per 1-h bright sunlight, p = 8.06e(-6))). The direction of effects was generally consistent between the OBB and NEO, although effect sizes were generally larger in the OBB.Conclusions: Increased bright sunlight duration is associated with an improved metabolic profile whilst higher outdoor temperature may adversely impact cardiometabolic health. (C) 2020 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. Show less
Atherothrombosis is a complication of atherosclerosis that causes acute cardiovascular events such as myocardial infarction and stroke. Circulating lipid levels are highly correlated with... Show moreAtherothrombosis is a complication of atherosclerosis that causes acute cardiovascular events such as myocardial infarction and stroke. Circulating lipid levels are highly correlated with atherosclerotic plaque development. In addition, experimental evidence suggests that lipids also directly influence thrombosis and influence the risk and the outcome of acute cardiovascular events. Plasma lipoproteins influence three aspects important to atherothrombosis: endothelial function, platelet aggregation (primary coagulation) and secondary coagulation. Overall, VLDL, LDL and oxLDL promote thrombus formation, whereas HDL shows antithrombotic actions. In this review we will address the current knowledge about modulation of atherothrombosis by lipoproteins, summarizing findings from in vitro and in vivo animal studies, as well as from observational and interventional studies in humans. We will conclude with future perspectives for lipid modulation in the prevention of atherothrombosis. Show less
Nordestgaard, B.G.; Langsted, A.; Mora, S.; Kolovou, G.; Baum, H.; Bruckert, E.; ... ; European Federation Clinical Chem 2016
Conclusion We recommend that non-fasting blood samples be routinely used for the assessment of plasma lipid profiles. Laboratory reports should flag abnormal values on the basis of desirable... Show moreConclusion We recommend that non-fasting blood samples be routinely used for the assessment of plasma lipid profiles. Laboratory reports should flag abnormal values on the basis of desirable concentration cut-points. Non-fasting and fasting measurements should be complementary but not mutually exclusive. Show less
The studies described in this thesis show that inflammation and CETP are both important factors in lipid metabolism and atherosclerosis. In the first part of this thesis we showed that high dietary... Show moreThe studies described in this thesis show that inflammation and CETP are both important factors in lipid metabolism and atherosclerosis. In the first part of this thesis we showed that high dietary cholesterol can induce hepatic inflammation via disturbed cholesterol homeostasis and ER stress, revealing new targets for the treatment of metabolic inflammation. Next, we demonstrated that intervention in both systemic and vascular inflammation can reduce atherosclerosis progression and/ or induce regression, highlighting the importance of developing drugs targeting the inflammatory component of atherosclerotic disease. In the second part of this thesis we showed that CETP inhibition per se may be anti-atherogenic, but that combination therapy of the CETP inhibitor torcetrapib with atorvastatin may have obscured its atheroprotective effect. Furthermore, we showed that the VLDL-increasing effect of CETP largely explains its atherogenic effect, at least in APOE*3-Leiden.CETP mice, and that CETP inhibition may negatively affect lesion stability. Our data suggest that CETP inhibition may not be the most optimal strategy to increase HDL-C levels and thereby reduce atherosclerosis. We anticipate that strategies improving HDL functionality, rather than raising the HDL level, are more likely to effectively reduce CVD. Show less
The research described in this thesis focussed on the role of apolipoproteins in lipid metabolism, inflammation and bacterial sepsis, with specific emphasis on apoCI. From studies in human APOC1_... Show moreThe research described in this thesis focussed on the role of apolipoproteins in lipid metabolism, inflammation and bacterial sepsis, with specific emphasis on apoCI. From studies in human APOC1_-transgenic and apoc1-/- mice, we were able to identify apoCI as a potent inhibitor of triglyceride hydrolysis by inhibiting lipoprotein lipase. Since APOC1 mice have thus increased VLDL levels, and VLDL protects against bacterial infection, we studied whether apoCI could play a role in inflammation and infection. We found that apoCI was able to bind lipopolysaccharide (LPS), the main toxic component of Gram-negative bacteria. Interestingly, although other apolipoproteins which have been studied have anti-inflammatory properties, we found that apoCI is a pro-inflammatory protein. By enhancing the biological response towards LPS and Gram-negative bacteria, apoCI dose-dependently improved the anti-bacterial attack, and protected against intrapulmonal Klebsiella pneumoniae-induced sepsis. Consistent with these experimental findings we also found that subjects with high plasma apoCI levels were less prone to infection-related mortality during follow-up, independent of plasma lipid levels. Likewise, survivors of severe sepsis showed higher plasma apoCI levels as compared to non-survivors, again independent of lipid levels. Taken together, our findings indicate that apoCI is an important determinant of the inflammatory response in mice and humans. Show less
This thesis contributes to a better understanding of the roles of apoCI, LPL, and CETP in lipoprotein metabolism. Our data illustrate that the activity of LPL, and thereby the level of plasma TG,... Show moreThis thesis contributes to a better understanding of the roles of apoCI, LPL, and CETP in lipoprotein metabolism. Our data illustrate that the activity of LPL, and thereby the level of plasma TG, is crucially determined by the relative abundance of apolipoproteins. In addition, we showed that LPL is an important determinant in remnant-particle clearance in the absence of the three main apoE-recognizing receptors. Finally, we demonstrated that CETP presents a pro-atherogenic factor in mice resembling a human lipid distribution over lipoproteins and that atorvastatin and fenofibrate treatment influence HDL-metabolism via inhibition of CETP, which may thus add to their therapeutic benefit. Since there were initial concerns that inhibition of CETP would reduce the flux of cholesteryl esters from the periphery back to the liver, thereby possibly increasing the risk for atherosclerosis, it is of interest that we found that fenofibrate-mediated inhibition of CETP did not hamper the total flux of HDL-cholesteryl esters. This holds promise for therapies based on CETP inhibition. Show less
