logo logo
[Dysfunctional High-Density Lipoproteins: Role in Atherogenesis and Potential Targets for Phospholipid Therapy]. Torchovskaya T I,Kudinov V A,Zakharova T S,Markin S S Kardiologiia In recent years the number of articles on damages of high-density lipoproteins (HDL) properties in patients with atherosclerosis has sharply increased. First, it concerns their ability to accept cholesterol (CH) from macrophages - the basis of antiatherogenic action of HDL. This ability was assessed ex vivo - by activity of cell cholesterol (CH) efflux to HDL or into patient's serum. In many works inverse relationship was shown between CH acceptor capacity of HDL and severity of atherosclerotic disease or frequency of its exacerbations during long-term observation, independent from HDL CH concentration. This led to the emergence of the concept of importance of "not only HDL quantity but also of their quality", i. e. functionality. In this review we consider pathways of cellular CH efflux (mainly mediated by cell proteins), methods used for detection of dysfunctional HDL, and results of relevant studies in various categories of patients. These studies directed to identification of mechanisms of damages of HDL properties by means of analysis of their composition, used various approaches including those of proteomics and lipidomics. However, now there are no proven targets for correction of HDL dysfunctionality. The only factor, that is underlined by many authors, is the significance of HDL phospholipids, which level correlates with activity of cellular CH efflux. This allows to take a fresh look at previously used phospholipid therapy of atherosclerosis. Its mechanism is apparently not lowering of plasma CH, as was previously expected, but the improvement of HDL antiatherogenic properties. For its practical usage it is necessary to elaborate principally novel formulations with high bioavailability of phospholipids - for HDL enrichment by phospholipid and thereby normalization of their ability to remove CH from tissues.
Fluorescent probes sensitive to changes in the cholesterol-to-phospholipids molar ratio in human platelet membranes during atherosclerosis. Posokhov Yevgen Methods and applications in fluorescence Environment-sensitive fluorescent probes were used for the spectroscopic visualization of pathological changes in human platelet membranes during cerebral atherosclerosis. It has been estimated that the ratiometric probes 2-(2'-hydroxyphenyl)-5-phenyl-1,3,4-oxadiazole and 2-phenyl-phenanthr[9,10]oxazole can detect changes in the cholesterol-to-phospholipids molar ratio in human platelet membranes during the disease. 10.1088/2050-6120/4/3/034013
Differential stability of high-density lipoprotein subclasses: effects of particle size and protein composition. Gao Xuan,Yuan Shujun,Jayaraman Shobini,Gursky Olga Journal of molecular biology High-density lipoproteins (HDLs) are complexes of proteins (mainly apoA-I and apoA-II) and lipids that remove cholesterol and prevent atherosclerosis. Understanding the distinct properties of the heterogeneous HDL population may aid the development of new diagnostic tools and therapies for atherosclerosis. Mature human HDLs form two major subclasses differing in particle diameter and metabolic properties, HDL(2) (large) and HDL(3) (small). These subclasses are comprised of HDL(A-I) containing only apoA-I, and HDL(A-I/A-II) containing apoA-I and apoA-II. ApoA-I is strongly cardioprotective, but the function of the smaller, more hydrophobic apoA-II is unclear. ApoA-II is thought to counteract the cardioprotective action of apoA-I by stabilizing HDL particles and inhibiting their remodeling. To test this notion, we performed the first kinetic stability study of human HDL subclasses. The results revealed that the stability of plasma spherical HDL decreases with increasing particle diameter; which may facilitate preferential cholesterol ester uptake from large lipid-loaded HDL(2). Surprisingly, size-matched plasma HDL(A-I/A-II) showed comparable or slightly lower stability than HDL(A-I); this is consistent with the destabilization of model discoidal HDL observed upon increasing the A-II to A-I ratio. These results clarify the roles of the particle size and protein composition in HDL remodeling, and help reconcile conflicting reports regarding the role of apoA-II in this remodeling. 10.1016/j.jmb.2009.02.036
HDL particle size is a critical determinant of ABCA1-mediated macrophage cellular cholesterol export. Du Xian-Ming,Kim Mi-Jurng,Hou Liming,Le Goff Wilfried,Chapman M John,Van Eck Miranda,Curtiss Linda K,Burnett John R,Cartland Sian P,Quinn Carmel M,Kockx Maaike,Kontush Anatol,Rye Kerry-Anne,Kritharides Leonard,Jessup Wendy Circulation research RATIONALE:High-density lipoprotein (HDL) is a heterogeneous population of particles. Differences in the capacities of HDL subfractions to remove cellular cholesterol may explain variable correlations between HDL-cholesterol and cardiovascular risk and inform future targets for HDL-related therapies. The ATP binding cassette transporter A1 (ABCA1) facilitates cholesterol efflux to lipid-free apolipoprotein A-I, but the majority of apolipoprotein A-I in the circulation is transported in a lipidated state and ABCA1-dependent efflux to individual HDL subfractions has not been systematically studied. OBJECTIVE:Our aims were to determine which HDL particle subfractions are most efficient in mediating cellular cholesterol efflux from foam cell macrophages and to identify the cellular cholesterol transporters involved in this process. METHODS AND RESULTS:We used reconstituted HDL particles of defined size and composition, isolated subfractions of human plasma HDL, cell lines stably expressing ABCA1 or ABCG1, and both mouse and human macrophages in which ABCA1 or ABCG1 expression was deleted. We show that ABCA1 is the major mediator of macrophage cholesterol efflux to HDL, demonstrating most marked efficiency with small, dense HDL subfractions (HDL3b and HDL3c). ABCG1 has a lesser role in cholesterol efflux and a negligible role in efflux to HDL3b and HDL3c subfractions. CONCLUSIONS:Small, dense HDL subfractions are the most efficient mediators of cholesterol efflux, and ABCA1 mediates cholesterol efflux to small dense HDL and to lipid-free apolipoprotein A-I. HDL-directed therapies should target increasing the concentrations or the cholesterol efflux capacity of small, dense HDL species in vivo. 10.1161/CIRCRESAHA.116.305485
Recent development on liquid chromatography-mass spectrometry analysis of oxidized lipids. Li Luxiao,Zhong Shanshan,Shen Xia,Li Qiujing,Xu Wenxin,Tao Yongzhen,Yin Huiyong Free radical biology & medicine Polyunsaturated fatty acids (PUFAs) in the cellular membrane can be oxidized by various enzymes or reactive oxygen species (ROS) to form many oxidized lipids. These metabolites are highly bioactive, participating in a variety of physiological and pathophysiological processes. Mass spectrometry (MS), coupled with Liquid Chromatography, has been increasingly recognized as an indispensable tool for the analysis of oxidized lipids due to its excellent sensitivity and selectivity. We will give an update on the understanding of the molecular mechanisms related to generation of various oxidized lipids and recent progress on the development of LC-MS in the detection of these bioactive lipids derived from fatty acids, cholesterol esters, and phospholipids. The purpose of this review is to provide an overview of the formation mechanisms and technological advances in LC-MS for the study of oxidized lipids in human diseases, and to shed new light on the potential of using oxidized lipids as biomarkers and mechanistic clues of pathogenesis related to lipid metabolism. The key technical problems associated with analysis of oxidized lipids and challenges in the field will also discussed. 10.1016/j.freeradbiomed.2019.06.006
High-density lipoprotein and atherosclerosis regression: evidence from preclinical and clinical studies. Feig Jonathan E,Hewing Bernd,Smith Jonathan D,Hazen Stanley L,Fisher Edward A Circulation research High-density lipoprotein (HDL) particles transport (among other molecules) cholesterol (HDL-C). In epidemiological studies, plasma HDL-C levels have an inverse relationship to the risk of atherosclerotic cardiovascular disease. It has been assumed that this reflects the protective functions of HDL, which include their ability to promote cholesterol efflux. Yet, several recent pharmacological and genetic studies have failed to demonstrate that increased plasma levels of HDL-C resulted in decreased cardiovascular disease risk, giving rise to a controversy regarding whether plasma levels of HDL-C reflect HDL function, or that HDL is even as protective as assumed. The evidence from preclinical and (limited) clinical studies shows that HDL can promote the regression of atherosclerosis when the levels of functional particles are increased from endogenous or exogenous sources. The data show that regression results from a combination of reduced plaque lipid and macrophage contents, as well as from a reduction in its inflammatory state. Although more research will be needed regarding basic mechanisms and to establish that these changes translate clinically to reduced cardiovascular disease events, that HDL can regress plaques suggests that the recent trial failures do not eliminate HDL from consideration as an atheroprotective agent but rather emphasizes the important distinction between HDL function and plasma levels of HDL-C. 10.1161/CIRCRESAHA.114.300760
Novel liquid chromatography-mass spectrometrymethod to analyze hdl lipidome. Patologicheskaia fiziologiia i eksperimental'naia terapiia Subject:High-density lipoprotein (HDL) is highly heterogeneous in function, structure, and composition. Components of HDL can be assayed using various techniques, including LC/MC approaches. The purpose of this study was to develop a novel method for the analysis of the HDL lipidome. Since phospholipids represent a major bioactive lipid component of HDL, the phosphosphingolipidome of major normolipidemic HDL subpopulations was characterized in this study. Methods and Results:The article describes the methodology used for the analysis of the HDL lipidome. Based on existing methods of lipidomic analysis, an original method of analyzing lipidome of HDL by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI/MS/MS) was developed. This technique was used to analyze the lipidome of five normolipidemic HDL subpopulations. Conclusion:The developed method allowed to identify and quantify 162 individual molecular lipid species in five normolipidemic HDL subpopulations across nine lipid subclasses, including 23 phosphatidylcholine, 22 sphingomyelin, 9lysophosphatidylcholine, 25 phosphatidylethanolamine, 17 phosphatidylinositol, 11 phosphatidylglycerol, 24 ceramide, 18 phosphatidylserine, and 13 phosphatidic acid species.
The measurement of high-density lipoprotein mediated cholesterol efflux from macrophage cells by liquid chromatography tandem mass spectrometry. Wang Mo,Guo Hanbang,Wang Siming,Yang Ruiyue,Li Hongxia,Zhao Haijian,Wang Shu,Dong Jun,Chen Wenxiang Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology BACKGROUND:Studies have shown a negative association between macrophage cholesterol efflux and atherosclerotic cardiovascular diseases (CVD). However, the current methods for measuring cholesterol efflux require a radioactive tracer and involve a variety of cell treatments, making the measurement of macrophage cholesterol efflux impractical for use in clinical laboratories. In this study, we developed a non-radioactive and precise LC/MS/MS method for the measurement of high-density lipoprotein (HDL) mediated cholesterol efflux from J774 macrophages. METHODS:J774 cells were seeded on 12-well plates at a density of 1.5×10(5) cells/ml in H-DMEM medium, and when the cells were approximately 80% confluent, they were incubated with H-DMEM medium containing 2% FBS, 0.5 μg/ml ACAT inhibitor Sandoz 58-035, and 20 μg/ml [3,4-(13)C]cholesterol for 6 h. After washing and equilibrating the cells, HDL samples were added at a final concentration of 7% and incubated for 8 h. The cells were lysed, and [3,4-(13)C]cholesterol and cholesterol were measured by LC/MS/MS. Cholesterol efflux was expressed as the percent decrease of cell [3,4-(13)C]cholesterol mass during the incubation. RESULTS:When incubated with [3,4-(13)C]cholesterol enriched J774 cells, HDL mediated higher cell cholesterol efflux than influx compared to serum and isolated LDL; therefore, HDL was used as the extracellular acceptor. The results from healthy volunteers showed that the rate of cholesterol efflux was negatively correlated with weight, BMI, blood pressure, and FERHDL and positively correlated with HDL-C, HDL2-C, and apoAI levels. CONCLUSIONS:A LC/MS/MS method for the measurement of HDL mediated cholesterol efflux from macrophage cells has been established. This method is non-radioactive, precise and reliable and is potentially useful for the assessment of HDL function and cardiovascular disease risks. 10.1159/000366388
Apigenin Retards Atherogenesis by Promoting ABCA1-Mediated Cholesterol Efflux and Suppressing Inflammation. Ren Kun,Jiang Ting,Zhou Hui-Fang,Liang Yin,Zhao Guo-Jun Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology BACKGROUND/AIMS:The development of atherosclerosis is accompanied by escalating inflammation and lipid accumulation within blood vessel walls. ABCA1 plays a crucial role in mediating cholesterol efflux from macrophages, which protects against atherogenesis. This research was designed to explore the effects and underlying mechanisms of apigenin (4', 5, 7-trihydroxyflavone) on ABCA1-mediated cellular cholesterol efflux and LPS-stimulated inflammation in RAW264.7 macrophages and apoE-/- mice. METHODS:Expression of genes or proteins was examined by RT-PCR or western blot analysis. Liquid scintillation counting was used to detect percent cholesterol efflux. Cellular cholesterol content was measured using HPLC assay. The secretion levels of pro-inflammatory cytokines were quantified by ELISA assay. Atherosclerotic lesion sizes were determined with Oil Red O staining. The contents of macrophages and smooth muscle cells in atherosclerotic lesion were evaluated using immunohistochemistry. Plasma TC, TG, HDL-C and LDL-C levels in apoE-/- mice were evaluated using commercial test kits. RESULTS:Apigenin potently increased ABCA1 expression through miR-33 repression in a dose- and time-dependent manner. Treatment with apigenin significantly increased ABCA1-mediated cholesterol efflux, and reduced TC, FC and CE levels in macrophage-derived foam cells. In LPS-treated macrophages, the expression levels of TLR-4, MyD88 and p-IκB-α as well as nuclear NF-κB p65 were decreased by the addition of apigenin. Moreover, apigenin markedly decreased secretion levels of several pro-inflammatory cytokines. Lastly, in LPS-challenged apoE-/- mice, apigenin administration augmented ABCA1 expression, decreased the contents of macrophages and smooth muscle cells in atherosclerotic lesion, reduced miR-33, TLR-4, and NF-κB p65 levels, improved plasma lipid profile and relieved inflammation, which results in less atherosclerotic lesion size. CONCLUSIONS:Taken together, these results suggest that apigenin may attenuate atherogenesis through up-regulating ABCA1-mediated cholesterol efflux and inhibiting inflammation. 10.1159/000491528
Melatonin directly interacts with cholesterol and alleviates cholesterol effects in dipalmitoylphosphatidylcholine monolayers. Choi Youngjik,Attwood Simon J,Hoopes Matthew I,Drolle Elizabeth,Karttunen Mikko,Leonenko Zoya Soft matter Melatonin is a pineal hormone that has been shown to have protective effects in several diseases that are associated with cholesterol dysregulation, including cardiovascular disease, Alzheimer's disease, and certain types of cancers. Cholesterol is a major membrane constituent with both a structural and functional influence. It is also known that melatonin readily partitions into cellular membranes. We investigated the effects of melatonin and cholesterol on the structure and physical properties of a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayer as a simple membrane model using the Langmuir-Blodgett (L-B) monolayer technique and molecular dynamics (MD) simulations. We report that melatonin increases the area per lipid and elastic compressibility of the DPPC monolayer in a concentration dependent manner, while cholesterol has the opposite effect. When both melatonin and cholesterol were present in the monolayer, the compression isotherms showed normalization of the area per molecule towards that of the pure DPPC monolayer, thus indicating that melatonin counteracts and alleviates cholesterol's effects. Atomistic MD simulations of melatonin enriched DPPC systems correlate with our experimental findings and illustrate the structural effects of both cholesterol and melatonin. Our results suggest that melatonin is able to lessen the influence of cholesterol through two different mechanisms. Firstly, we have shown that melatonin has a fluidizing effect on monolayers comprising only lipid molecules. Secondly, we also observe that melatonin interacts directly with cholesterol. Our findings suggest a direct nonspecific interaction of melatonin may be a mechanism involved in reducing cholesterol associated membrane effects, thus suggesting the existence of a new mechanism of melatonin's action. This may have important biological relevance in addition to the well-known anti-oxidative and receptor binding effects. 10.1039/c3sm52064a
The Mystery behind the Pineal Gland: Melatonin Affects the Metabolism of Cholesterol. Karolczak Kamil,Watala Cezary Oxidative medicine and cellular longevity Melatonin may be considered a cardioprotective agent. Since atherogenesis is partly associated with the metabolism of lipoproteins, it seems plausible that melatonin affects cardiovascular risk by modulating the metabolism of cholesterol and its subfractions. Moreover, cholesterol-driven atherogenesis can be hypothetically reduced by melatonin, mainly due to the minimalization of harmful reactions triggered in the cardiovascular system by the reactive oxygen species-induced toxic derivatives of cholesterol. In this review, we attempted to summarize the available data on the hypolipemizing effects of melatonin, with some emphasis on the molecular mechanisms underlying these reactions. We aimed to attract readers' attention to the numerous gaps of knowledge present in the reviewed field and the essential irrelevance between the findings originating from different sources: clinical observations and mechanistic and molecular studies, as well as preclinical experiments involving animal models. Overall, such inconsistencies make it currently impossible to give a reliable opinion on the action of melatonin on the metabolism of lipoproteins. 10.1155/2019/4531865
[Melatonin in the treatment of atherosclerosis]. Broncel Marlena,Koziróg-Kołacińska Marzena,Chojnowska-Jezierska Julita Polski merkuriusz lekarski : organ Polskiego Towarzystwa Lekarskiego Atherosclerosis is currently concerned as a chronic inflammatory process, which is response to an endothelial damage. Therapy of atherosclerosis should influence on various mechanisms. Substances which can prevent and treat this disorder are still being investigated. Melatonin exerts anti-inflammatory and antioxidative properties, which implies that it can be useful in the treatment of atherosclerosis. Melatonin neutralizes ROS (reactive oxygen species), increases antioxidative enzymes activities and glutathione levels, prevents electron leakage from mitochondrial respiratory chain, acts synergistically with vitamins C, E, and glutathione. Melatonin reduces levels of proinflammatory cytokines: IL-6, IL-12, TNF-alpha, IFN-gamma. In vivo studies and experiments on animals melatonin exerts beneficial effect on serum lipids, prevents LDL oxidation, decreases TBARS levels, increases total antioxidant capacity. However, some studies suggest that melatonin can exert atherogenic effects in animals. Clinical studies on patients who are in risk of atherosclerosis development are required.
Melatonin Ameliorates the Progression of Atherosclerosis via Mitophagy Activation and NLRP3 Inflammasome Inhibition. Ma Sai,Chen Jiangwei,Feng Jing,Zhang Ran,Fan Miaomiao,Han Dong,Li Xiang,Li Congye,Ren Jun,Wang Yabin,Cao Feng Oxidative medicine and cellular longevity The NLRP3 (nucleotide-binding domain and leucine-rich repeat pyrin domain containing 3) inflammasome-mediated inflammatory responses are critically involved in the progression of atherosclerosis (AS), which is the essential cause for cardiovascular diseases. Melatonin has anti-inflammatory properties. However, little is known about the potential effects of melatonin in the pathological process of AS. Herein, we demonstrate that melatonin suppressed prolonged NLRP3 inflammasome activation in atherosclerotic lesions by reactive oxygen species (ROS) scavenging via mitophagy in macrophages. The atherosclerotic mouse model was induced with a high-fat diet using ApoE mice. Melatonin treatment markedly attenuated AS plaque size and vulnerability. Furthermore, melatonin decreased NLRP3 inflammasome activation and the consequent IL-1 secretion within atherosclerotic lesions. Despite the unchanged protein expression, the silent information regulator 3 (Sirt3) activity was elevated in the atherosclerotic lesions in melatonin-treated mice. In ox-LDL-treated macrophages, melatonin attenuated the NLRP3 inflammasome activation and the inflammatory factors secretion, while this protective effect was abolished by either Sirt3 silence or autophagy inhibitor 3-MA. Mitochondrial ROS (mitoROS), which was a recognized inducer for NLRP3 inflammasome, was attenuated by melatonin through the induction of mitophagy. Both Sirt3-siRNA and autophagy inhibitor 3-MA partially abolished the beneficial effects of melatonin on mitoROS clearance and NLRP3 inflammasome activation, indicating the crucial role of Sirt3-mediated mitophagy. Furthermore, we demonstrated that melatonin protected against AS via the Sirt3/FOXO3a/Parkin signaling pathway. In conclusion, the current study demonstrated that melatonin prevented atherosclerotic progression, at least in part, via inducing mitophagy and attenuating NLRP3 inflammasome activation, which was mediated by the Sirt3/FOXO3a/Parkin signaling pathway. Collectively, our study provides insight into melatonin as a new target for therapeutic intervention for AS. 10.1155/2018/9286458
Melatonin Inhibits in Vitro Smooth Muscle Cell Inflammation and Proliferation and Atherosclerosis in Apolipoprotein E-Deficient Mice. Li Hung-Yuan,Leu Yann-Lii,Wu Ya-Chieh,Wang Shu-Huei Journal of agricultural and food chemistry Chronic inflammation and proliferation play important roles in atherosclerosis progression. This study aimed to identify the mechanisms responsible for the anti-inflammatory and antiproliferative effects of melatonin on tumor necrosis factor-α (TNF-α)- and platelet-derived growth factor-BB (PDGF-BB)-treated rat aortic smooth muscle cells (RASMCs). Melatonin reduced TNF-α-induced RASMC inflammation by decreasing vascular cell adhesion molecule-1 (VCAM-1) expression and nuclear factor-kappa B (NF-κB) P65 activity by inhibiting P38 mitogen-activated protein kinase phosphorylation ( P < 0.05). Additionally, melatonin inhibited PDGF-BB-induced RASMC proliferation by reducing mammalian target of rapamycin (mTOR) phosphorylation ( P < 0.05) but not migration in vitro. Melatonin also reduced TNF-α- and PDGF-BB-induced reactive oxygen species (ROS) production ( P < 0.05). Furthermore, melatonin treatment (prevention and treatment groups) significantly repressed high cholesterol diet-stimulated atherosclerotic lesions in vivo (19.59 ± 4.11%, 20.28 ± 5.63%, 32.26 ± 12.06%, respectively, P < 0.05). Taken together, the present study demonstrated that melatonin attenuated TNF-α-induced RASMC inflammation and PDGF-BB-induced RASMC proliferation in cells and reduced atherosclerotic lesions in mice. These results showed that melatonin has anti-inflammatory and antiproliferative properties and may be a novel therapeutic target in atherosclerosis. 10.1021/acs.jafc.8b06217
Melatonin and its atheroprotective effects: a review. Favero Gaia,Rodella Luigi Fabrizio,Reiter Russel J,Rezzani Rita Molecular and cellular endocrinology Atherosclerosis is a chronic vascular disease in which oxidative stress and inflammation are commonly implicated as major causative factors. Identification of novel strategies that contribute to plaque stabilization or inhibition represents a continuing challenge for the medical community. The evidence from the last decade highlights that melatonin influences the cardiovascular system, but its mechanisms of action have not been definitively clarified. Melatonin has atheroprotective effects by acting on different pathogenic signaling processes; these result from its direct free radical scavenger activity, its indirect antioxidant properties and its anti-inflammatory actions. In this review, we summarize the many pieces of the puzzle which identified molecular targets for prevention and therapy against the atherosclerotic pathogenic processes and we evaluate the data documenting that melatonin treatment has important actions that protect against atherosclerosis and atherosclerosis-related cardiovascular diseases. 10.1016/j.mce.2013.11.016