Lipidomic alterations in lipoproteins of patients with mild cognitive impairment and Alzheimer’s disease by asymmetrical flow field-flow fractionation and nanoflow ultrahigh performance liquid chromatography-tandem mass spectrometry

Kim, San Ha,Yang, Joon Seon,Lee, Jong Cheol,Lee, Ji-Yeon,Lee, Jun-Young,Kim, Eosu,Moon, Myeong Hee Elsevier 2018 Journal of chromatography Vol.1568 No.-

<P><B>Abstract</B></P> <P>Alzheimer’s disease (AD) is an irreversible neurodegenerative disorder with the clinical symptom of the progressive loss of cognitive function and mild cognitive impairment (MCI) is a translational state between cognitive changes of normal aging and AD. Lipid metabolism and pathogenesis of Alzheimer’s disease (AD) are closely linked. Despite obviously discrete lipidome constitutions across lipoproteins, lipidomic approaches of AD has been mostly conducted without considering lipoprotein-dependent alterations. This study introduces a combination of asymmetrical flow field-flow fractionation (AF4) and nanoflow ultrahigh performance liquid chromatography-tandem mass spectrometry (nUHPLC-ESI-MS/MS) for a comprehensive lipid profiling in different lipoprotein level of patients plasma with AD and amnestic MCI in comparison to age-matched healthy controls. Lipoproteins in plasma samples were size-sorted by a semi-preparative scale AF4, followed by non-targeted lipid identification and high speed targeted quantitation with nUHPLC-ESI-MS/MS. It shows 14 significantly altered high abundance lipids in AD, exhibiting >2-fold increases (<I>p </I>< 0.01) in LDL/VLDL including triacylglycerol, ceramide, phosphatidylethanolamine, and diacylglycerol. Three lipid species (triacylglycerol 50:1, diacylglycerol 18:1_18:1, and phosphatidylethanolamine 36:2) showing a strong correlation with the degree of brain atrophy were found as candidate species which can be utilized to differentiate the early stage of MCI when simple Mini-Mental State Examination results were statistically incorporated. The present study elucidated lipoprotein-dependent alterations of lipids in progression of MCI and further to AD which can be utilized for the future development of lipid biomarkers to enhance the predictability of disease progress.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lipoprotein-dependent lipidomic analysis of Alzheimer’s disease. </LI> <LI> Size-sorting of lipoproteins by Flow FFF and lipid analysis by nUHPLC-MS/MS. </LI> <LI> Fourteen high-abundance lipids showed significant changes in Alzheimer’s disease. </LI> <LI> Three lipids in LDL/VLDL were specific to mild cognitive impairment. </LI> </UL> </P>

Detailed analysis of the plasma extracellular vesicle proteome after separation from lipoproteins

Karimi, Nasibeh,Cvjetkovic, Aleksander,Jang, Su Chul,Crescitelli, Rossella,Hosseinpour Feizi, Mohammad Ali,Nieuwland, Rienk,Lö,tvall, Jan,Lä,sser, Cecilia Springer International Publishing 2018 Cellular and Molecular Life Sciences Vol.75 No.15

<P>The isolation of extracellular vesicles (EVs) from blood is of great importance to understand the biological role of circulating EVs and to develop EVs as biomarkers of disease. Due to the concurrent presence of lipoprotein particles, however, blood is one of the most difficult body fluids to isolate EVs from. The aim of this study was to develop a robust method to isolate and characterise EVs from blood with minimal contamination by plasma proteins and lipoprotein particles. Plasma and serum were collected from healthy subjects, and EVs were isolated by size-exclusion chromatography (SEC), with most particles being present in fractions 8–12, while the bulk of the plasma proteins was present in fractions 11–28. Vesicle markers peaked in fractions 7–11; however, the same fractions also contained lipoprotein particles. The purity of EVs was improved by combining a density cushion with SEC to further separate lipoprotein particles from the vesicles, which reduced the contamination of lipoprotein particles by 100-fold. Using this novel isolation procedure, a total of 1187 proteins were identified in plasma EVs by mass spectrometry, of which several proteins are known as EV-associated proteins but have hitherto not been identified in the previous proteomic studies of plasma EVs. This study shows that SEC alone is unable to completely separate plasma EVs from lipoprotein particles. However, combining SEC with a density cushion significantly improved the separation of EVs from lipoproteins and allowed for a detailed analysis of the proteome of plasma EVs, thus making blood a viable source for EV biomarker discovery.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1007/s00018-018-2773-4) contains supplementary material, which is available to authorized users.</P>

Tumor Necrosis Factor-Alpha Induced VCAM-1 Expression is Inhibited by High Density Lipoprotein in Human Astroglioma Cells

Yadav Wagley,Jae-Wook Oh(오재욱) 대한체질인류학회 2008 대한체질인류학회지 Vol.21 No.3

중추신경계에서 교세포의 대다수를 차지하는 Astrocytes는, 사이토카인 TNF-α 등의 자극으로 여러 혈관 세포유착인자들 중, vascular cell adhesion molecule-l (VCAM-l)의 발현을 증가시킨다. 이렇게 증가된 YCAM-l의 발현은 중추신경계의 염증과정에서 중요한 역할을 수행한다. Astrocyte cells 이 apo E 등을 포함하는 HDL-like lipoprotein particles을 분비함이 최근에 밝혀졌기 때문에, 우리는 astroglioma 세포를 가지고 YCAM-1 발현변화에 초점을 두고 인체 혈장에서 분리된 HDL, YLDL 그리고 LDL 등 다른 lipoproteins들의 YCAM-l 발현 조절 가능성을 조사하였다. Astroglioma세포에 VLDL, LDL 그리고 HDL등의 단독처리는 VCAM-l 발현변화에 아무런 영향이 없었다. 그러나 Astroglioma세포에서 HDL이 흥미롭게도 농도의존성으로 TNF-α에 의해 증가된 VCAM-1 발현을 억제시켰다. 그러나 비슷한 구조를 갖는 VLDL, LDL은 이러한 억제성을 보여주질 못했다. 특이성 실험에서, TNF-α에 의해 증가된 VCAM-1 발현에 대한 HDL억제성은 HDL의 주요 apolipoprotein 구성원인 Apo A-1 항체의 전처리로 언해 다시 증가됨을 확인하였다. 이는 곧 HDL의 Apo A-1이 이러한 억제기능에 중요한 역할이 있음을 의미한다. 게다가 Reconstituted HDL (apo HDL과 DMPC의 discoidal complexes) 또한 VCAM-1 발현증가를 억제함을 알 수 있었다. RNase protection assay (RPA) 실험에서, TNF-α에 의해 증가된 VCAM-l mRNA 발현증가 역시 HDL에 의해 억제되었다. 이러한 결과들은 질환상태의 중추신경계에서 HDL-like particles이 면역억제기능을 수행할 수 있음을 제시한다. Astrocytes, the major glial cells in the central nervous system (CNS), can express vascular cell adhesion molecule-l (YCAM-l) in response to cytokines, such as TNF-a. In CNS, an increased YCAM-l expression may contribute to inflammatory processes. We, in the present study, have examined the effect of human plasma High Density Lipoproteins (HDL) and other lipoproteins on YCAM-l expression in astroglioma cells since astrocytes secrete HDL-like lipoprotein particles which contain apo E and cholesterol, phospholipid. The exposure of astroglioma cells to the major plasma lipoprotein fractions (YLDL, LDL and HDL) had no effect on the YCAM-l expression. However, TNF-a-induced YCAM-l was inhibited by HDL in a dose-dependent manner, but not by YLDL or LDL. The inhibitory effect of HDL on TNF-α-induced YCAM-l was reversed by the inclusion of Apo A-I antibody, the major apolipoprotein of HDL, demonstrating the specificity of this response. Reconstituted HDL (discoidal complex of apo HDL and DMPC), but not apo HDL or DMPC, was effective in suppressing the YCAM-l expression. RNase protection assay (RPA) revealed that TNF-ainduced YCAM-l mRNA expression was markedly inhibited by HDL (500㎍ cholesterol/㎖). These results indicate that HDL-like particles in the CNS may function as an immunosuppressive molecule in pathologic conditions of CNS.

Top-down lipidomic analysis of human lipoproteins by chip-type asymmetrical flow field-flow fractionation-electrospray ionization-tandem mass spectrometry

Kim, K.H.,Lee, J.Y.,Lim, S.,Moon, M.H. Elsevier 2013 Journal of chromatography A Vol.1280 No.-

This study demonstrates the potential utility of on-line chip-type asymmetrical flow field-flow fractionation (cAF4) and electrospray ionization tandem mass spectrometry (ESI-MS-MS) for the top-down lipidomic analysis of human lipoproteins. Utilizing a cAF4, which is a miniaturized AF4 channel operated with a micro flow rate regime, enabled high density lipoprotein (HDL) and low density lipoprotein (LDL) to be separated by hydrodynamic diameter in an aqueous solution with the simultaneous desalting of lipoproteins. On-line desalting was found to enhance the ionization of lipoproteinic lipid molecules during the feeding of cAF4 effluent to ESI-MS when compared to the direct infusion of lipoproteins to MS. An evaluation of top-down lipidomic analysis was performed to test the efficiency of in-source fragmentation during cAF4-ESI-MS in the dissociation of lipoprotein particles into individual lipid molecules. This study demonstrates the structural identification of the following lipid classes: phosphatidylcholines (PCs), cholesteryl esters (CEs), and regioisomers of triacylglycerols (TAGs) having an identical mass but different acyl chains and dimeric forms of TAGs in the positive ion mode, and phosphatidylglycerols (PGs), phosphatidic acids (PAs), phosphatidyinositols (PIs), and their lyso species in the negative ion mode. The developed method was applied to plasma samples from patients with coronary artery disease (CAD) for the separation of HDL and LDL and for the simultaneous analysis of lipoproteinic lipids, resulting in the identification of 11 PCs, 9 PGs, 4 PAs, 2 PIs, 2 PEs, 18 TAGs, and 6 CEs.

Effects of the Transition from Premenopause to Postmenopause on Lipids and Lipoproteins: Quantification and Related Parameters

( Eun Jeung Cho ),( Yun Joo Min ),( Min Seok Oh ),( Jee Eun Kwon ),( Jeung Eun Kim ),( Wang Soo Lee ),( Kwang Je Lee ),( Sang Wook Kim ),( Tae Ho Kim ),( Myung A Kim ),( Chee Jeong Kim ),( Wang Seong 대한내과학회 2011 The Korean Journal of Internal Medicine Vol.26 No.1

Background/Aims: The aim of this study was to quantitatively measure changes in lipids and lipoproteins during perimenopause and to identify variables related to these changes. Methods: Among women who had three regular health evaluations over a span of 2-4 years, 34 women remained in the premenopausal state, 34 premenopausal women transitioned to the postmenopausal state, and 36 postmenopausal women were enrolled. The menopausal state was determined not only by a history of amenorrhea but also by levels of female sex hormones. Yearly changes in lipids were calculated using a linear regression of the three measurements. Results: The transition from premenopause to postmenopause was associated with increased total cholesterol and low-density lipoprotein (LDL) cholesterol levels by 7.4 ± 8.0 mg/dL (4.2 ± 4.9%) and 6.9 ± 6.5 mg/dL (6.8 ± 7.0 %) over one year, resulting in an elevation of 19.6 ± 22.6 mg/dL (10.9 ± 13.0%) and 18.9 ± 19.5 mg/dL (18.6 ± 20.3%), respectively, during perimenopause. There were no changes observed in premenopausal and postmenopausal women. Body weight, blood pressure, high-density lipoprotein (HDL) cholesterol, and triglycerides did not change in any of the three groups. In all women, changes in both total cholesterol and LDL cholesterol were associated with changes in follicle stimulating hormone (r = 0.40, p < 0.001 and r = 0.38, p < 0.001, respectively). Changes in triglycerides were associated with changes in body weight (r = 0.28, p = 0.005). Conclusions: During perimenopause, total and LDL cholesterol levels increase and these changes in cholesterol are mainly dependent on changes in female sex hormones. (Korean J Intern Med 2011;26:47-53)

장기간의 3 - hydroxy 3 - methyl glutaryl CoA reductase 억제제 투여가 lipoprotein ( a ) 농도에 미치는 효과

안지현(Ji Hyun Ahn),이상엽(Sang Yep Lee),조성원(Sung Won Cho),김상민(Sang Min Kim),송영빈(Young Bien Song),이광제(Kwang Je Lee),김상욱(Sang Wook Kim),고홍숙(Hong Sook Ko),김태호(Tae Ho Kim),김치정(Chee Jeong Kim),류왕성(Wang Seong Ry 대한내과학회 2002 대한내과학회지 Vol.63 No.3

목적 : 3-hydroxy 3-methyl glutaryl CoA reductase 억제제(이하 statin이라 약함)의 lipoprotein (a)[Lp(a)]에 대한 효과에 대해서는 약제의 종류나 투여기간에 따라 그 효과가 다르다는 보고들이 있어 논란이 있다. 이에 최소한 2년 이상의 장기적인 statin의 투여가 혈중 Lp(a)의 농도에 어떤 변화를 나타내는지를 후향적으로 분석해 보고자 하였다. 방법 : 최소한 2년 이상의 간격으로 지질과 Lp(a)를 반복 측정한 93명의 환자를 대상으로, 20 mg의 lovastatin을 복용한 군과(Statin군, n=33명), Lp(a)의 농도에 직접적인 영향이 없는 것으로 알려진 약제를 복용한 군으로(대조군, n=60명) 나누어 여러 지질과 함께 Lp(a) 농도의 변화를 관찰하였다. 결과 : 대조군과 statin군의 기본적인 임상적 지표들은 차이가 없었고, 추적기간은 statin군이 58.7±15.0개월(범위 32∼87개월)과 대조군이 54.7±16.4개월(범위 24 ∼81개월)로 역시 차이가 없었다(p=0.24). 20 mg의 lovastatin을 평균 58.7개월간 투여하였을 때에 Lp(a)의 농도는 변화가 없었으며(30.1±29.6 mg/dL vs. 28.2±23.1 mg/dL, p=0.89), 이는 대조군에서도 마찬가지였고, 농도의 변화량도 두 군간에 차이가 없었다. 총 콜레스테롤과 LDL-C의 농도는 statin 투여군에서 각각 26.4% (p=0.000)와 40.5%(p=0.000) 감소하였으며, HDL-C 농도는 statin군과 대조군에서 각각 13.6%(p=0.001)와 18.0%(p=0.000) 증가하였고, 변화양은 두 군간에 차이가 없었다(p=0.82). 결론 : 후향적 연구에서 장기간의 lovastatin 투여는 Lp(a)의 농도에 영향이 없었으며, HDL-C의 농도에 대해서도 효과가 미미하였다. 확실한 결론을 위해서는 향후 전향적 연구가 필요할 것으로 생각된다. Background : The effect of 3-hydroxy 3-methyl glutaryl CoA reductase inhibitor (statin) on the concentration of lipoprotein (a) [Lp(a)] is controversial. Most studies evaluated the effect of statin administered for less than 2 years. We were to analyze the effect of long-term treatment of statin on the concentration of Lp(a) retrospectively. Methods : A total 93 cases were enrolled and divided into two groups; statin group (20 mg of lovastatin, n=33) and control group (n=60). Lp(a) and lipid profiles were measured before and after the medication for at least 2 years. Results : Between two groups, there were no differences in baseline clinical variables and in biochemical parameters except total cholesterol and low density lipoprotein-cholesterol (LDL-C) levels. Mean duration of follow-up was similar between control and statin groups (58.7±15.0 vs. 54.7±16.4 months, p=0.24). Lp(a) levels did not change in both statin group (30.1±29.6 mg/dL vs. 28.2±23.1 mg/dL, p=0.89) and control group (p=0.49). The change of Lp(a) was not different between two groups (p=0.43). Statin was also ineffective in cases with Lp(a) level over 10 mg/dL. Total cholesterol and LDL-C levels decreased in statin group by 26.4% (p=0.000) and 40.5% (p=0.000) respectively. The elevation of HDL-C was similar between two groups. Conclusion : Long-term treatment of lovastatin did not modify Lp(a) level in retrospective study. To clarify the effect of statin precisely, prospective study might be needed.(Korean J Med 63:283-289, 2002)

Lack of Association Between Low Density Lipoprotein Particle Size and On-Treatment Platelet Reactivity in Patients With Coronary Artery Disease

강도윤,양한모,박경우,이소령,이민호,이동원,이해영,강현재,구본권,채인호,최동주,김효수,김철호 대한심장학회 2012 Korean Circulation Journal Vol.42 No.8

Background and Objectives: Small dense low density lipoproteins (sd-LDL) are a risk factor for coronary artery disease and are known to stimulate platelet function in vitro. This study aimed to evaluate whether high proportion of sd-LDL is associated with high on-treat-ment platelet reactivity (HOPR). Subjects and Methods: From January 2009 to March 2010, 439 subjects (mean age: 64.3±9.7, Male : Female=306 : 133) were enrolled from the low density LIPOProtein-cholesterol Size measurement Registry with coronary artery disease, who had undergone elective per-cutaneous coronary intervention and measured both LDL particle size and on-treatment platelet reactivity (OPR). Mean LDL particle size was measured by gradient gel electrophoresis (Quantimetrix, Lipoprint TM ) and OPR by the VerifyNow TM system (aspirin and P2Y12). Results: Between pattern A (large, buoyant LDL dominant) and B (sd-LDL dominant) population, there were no significant difference in OPR to aspirin (441.3±71.9 vs. 434.07±63.45 aspirin reaction units, p=0.351) or clopidogrel (237.9±87.3 vs. 244.9±80.7 P2Y12 reaction units, p=0.465). There was no difference in LDL particle size between patients with HOPR compared with non-HOPR patients (aspirin:26.8±0.5 vs. 26.7±0.6 nm, p=0.078, clopidogrel: 26.7±0.6 vs. 26.8±0.5 nm, p=0.857). Pearson’s correlation coefficients between LDL par-ticle size and platelet reactivity were not statistically significant (aspirin assay: r=0.080, p=0.098, P2Y12 assay: r=-0.027, p=0.568). Conclusion: There was no significant association between LDL particle size and OPR in patients with coronary artery disease.

Novel association between <i>CDKAL1</i> and cholesterol efflux capacity: Replication after GWAS-based discovery

Cheon, Eun Jeong,Cha, Do Hyeon,Cho, Sung Kweon,Noh, Hye-Min,Park, Sungha,Kang, Seok-Min,Gee, Heon Yung,Lee, Sang-Hak Elsevier 2018 Atherosclerosis Vol.273 No.-

<P><B>Abstract</B></P> <P><B>Background and aims</B></P> <P>Although the importance of the functional properties of high-density lipoprotein (HDL) has been increasingly emphasized, studies on the genetic factors associated with HDL function are highly limited. The aim of this study was to identify genetic variants associated with an individual's cholesterol efflux capacity (CEC) using a genome-wide association study approach.</P> <P><B>Methods</B></P> <P>This study included a discovery group of 607 subjects with coronary artery disease and an independent replication group of 158 subjects. CEC was assessed using a radioisotope and ApoB-depleted serum. Genome-wide associations between the adjusted CEC and genotyped and imputed variants were examined with linear regression, assuming an additive genetic model. Finally, adjustments were made for confounding parameters to assess the independence of associations and to determine R<SUP>2</SUP> of overall model on CEC.</P> <P><B>Results</B></P> <P>In the discovery group, 631 variants showed significant association with CEC, and five of them were found to correlate with CEC in the replication group. One of them was located near <I>LOC541471</I> in 2q13, whereas the other four (rs117835232, rs117252933, rs118064592, and rs150434350) were located in <I>CDKAL1</I> in 6p22.3. The association between the presence of any <I>CDKAL1</I> variant and CEC was significant after adjustment for clinical and laboratory variables. High-density lipoprotein-cholesterol levels also showed a very significant association with CEC. Body mass index, current alcohol use, triglycerides levels, low-density lipoprotein-cholesterol levels and statin use showed borderline associations with CEC.</P> <P><B>Conclusions</B></P> <P>We identified and replicated genetic variants associated with CEC using a genome-wide association study-based approach. <I>CDKAL1</I> variants showed correlations with CEC independent of HDL-cholesterol levels and other clinical characteristics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We identified and replicated genetic variants associated with cholesterol efflux capacity (CEC). </LI> <LI> One variant was located near <I>LOC541471</I> on 2q13, and four were in <I>CDKAL1</I> on 6p22.3 </LI> <LI> The association between any <I>CDKAL1</I> variant and CEC was significant after adjustment. </LI> </UL> </P>

High Density Lipoprotein: A Therapeutic Target in Type 2 Diabetes

Philip J. Barter 대한내분비학회 2013 Endocrinology and metabolism Vol.28 No.3

High density lipoproteins (HDLs) have a number of properties that have the potential to inhibit the development of atherosclerosis and thus reduce the risk of having a cardiovascular event. These protective effects of HDLs may be reduced in patients with type 2 diabetes, a condition in which the concentration of HDL cholesterol is frequently low. In addition to their potential cardioprotective properties, HDLs also increase the uptake of glucose by skeletal muscle and stimulate the synthesis and secretion of insulin from pancreatic β cells and may thus have a beneficial effect on glycemic control. This raises the possibility that a low HDL concentration in type 2 diabetes may contribute to a worsening of diabetic control. Thus, there is a double case for targeting HDLs in patients with type 2 diabetes: to reduce cardiovascular risk and also to improve glycemic control. Approaches to raising HDL levels include lifestyle factors such as weight reduction, increased physical activity and stopping smoking. There is an ongoing search for HDL-raising drugs as agents to use in patients with type 2 diabetes in whom the HDL level remains low despite lifestyle interventions.

High-Density Lipoprotein, Lecithin: Cholesterol Acyltransferase, and Atherosclerosis

Alice Ossoli,Chiara Pavanello,Laura Calabresi 대한내분비학회 2016 Endocrinology and metabolism Vol.31 No.2

Epidemiological data clearly show the existence of a strong inverse correlation between plasma high-density lipoprotein cholesterol(HDL-C) concentrations and the incidence of coronary heart disease. This relation is explained by a number of atheroprotectiveproperties of HDL, first of all the ability to promote macrophage cholesterol transport. HDL are highly heterogeneous andare continuously remodeled in plasma thanks to the action of a number of proteins and enzymes. Among them, lecithin:cholesterolacyltransferase (LCAT) plays a crucial role, being the only enzyme able to esterify cholesterol within lipoproteins. LCAT is synthetizedby the liver and it has been thought to play a major role in reverse cholesterol transport and in atheroprotection. However,data from animal studies, as well as human studies, have shown contradictory results. Increased LCAT concentrations are associatedwith increased HDL-C levels but not necessarily with atheroprotection. On the other side, decreased LCAT concentrationand activity are associated with decreased HDL-C levels but not with increased atherosclerosis. These contradictory resultsconfirm that HDL-C levels per se do not represent the functionality of the HDL system.