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Harsløf M, Pedersen KM, Afzal S, Davey Smith G, Nordestgaard BG. Lower levels of small HDL particles associated with increased infectious disease morbidity and mortality: a population-based cohort study of 30 195 individuals. Cardiovasc Res 2023; 119:957-968. [PMID: 36537045 DOI: 10.1093/cvr/cvac194] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/29/2022] [Accepted: 11/04/2022] [Indexed: 12/24/2022] Open
Abstract
AIMS Low levels of HDL cholesterol have been associated with increased risk of infectious disease morbidity and mortality. Nuclear magnetic resonance (NMR) spectroscopy permits the measurement of HDL particle count and allows further subclassification according to particle size. We tested the hypothesis that low number of different HDL subfractions is associated with increased infectious disease morbidity and mortality. METHODS AND RESULTS HDL particle counts were measured using NMR spectroscopy in 30 195 individuals aged 22-99 years from the Copenhagen General Population Study. Using multiple-event Cox regression and cause-specific hazard models, we assessed risk of hospitalizations due to infection and infectious disease-related death, from 2003 through 2018. During follow-up, 9303 individuals had one or more infectious disease events, and 1558 experienced infectious disease-related death. In multifactorial adjusted analyses, low number of small and medium HDL particles was associated with increased risk of any infection and infectious disease-related death, whereas low number of large and extra-large HDL particles was not. A very high number of small and medium HDL particles was also associated with increased risk of any infection, but not with infectious disease-related death. For small and medium HDL particles and compared to individuals in the 91-95th percentile, hazard ratios (HRs) in individuals in the lowest percentile were 2.31 (95% confidence interval: 1.75, 3.05) for any infection and 3.23 (2.08, 5.02) for infectious disease-related death. For the highest percentile, corresponding HRs were 1.36 (1.07, 1.74) and 1.06 (0.57, 1.98), respectively. Individuals in the lowest percentile had increased risk of pneumonia (HR: 1.86; 95% confidence interval: 1.30, 2.65), sepsis (2.17; 1.37, 3.35), urinary tract infection (1.76; 1.17, 2.63), skin infection (1.87; 1.24, 2.81), gastroenteritis (1.78; 1.01, 3.16), and other infections (2.57; 1.28, 5.16). CONCLUSION Low number of the small HDL particles was associated with increased infectious disease morbidity and mortality.
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Affiliation(s)
- Mads Harsløf
- Department of Clinical Biochemistry, Copenhagen University Hospital, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 73, DK-2730 Herlev, Denmark
- The Copenhagen General Population Study, Copenhagen University Hospital, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 73, DK-2730 Herlev, Denmark
| | - Kasper M Pedersen
- Department of Clinical Biochemistry, Copenhagen University Hospital, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 73, DK-2730 Herlev, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Shoaib Afzal
- Department of Clinical Biochemistry, Copenhagen University Hospital, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 73, DK-2730 Herlev, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - George Davey Smith
- MRC Integrative Epidemiology Unit (IEU), Bristol Medical School, University of Bristol, BS8 2BN Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, BS8 2BN Bristol, United Kingdom
| | - Børge G Nordestgaard
- Department of Clinical Biochemistry, Copenhagen University Hospital, Herlev and Gentofte Hospital, Borgmester Ib Juuls Vej 73, DK-2730 Herlev, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
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2
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Sim RZH, Tham YC, Betzler BK, Zhou L, Wang X, Sabanayagam C, Cheung GCM, Wong TY, Cheng CY, Nusinovici S. Relationships between Lipid-Related Metabolites and Age-Related Macular Degeneration Vary with Complement Genotype. OPHTHALMOLOGY SCIENCE 2022; 2:100211. [PMID: 36531576 PMCID: PMC9755028 DOI: 10.1016/j.xops.2022.100211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 06/17/2023]
Abstract
OBJECTIVE Lipid dysregulation and complement system (CS) activation are 2 important pathophysiology pathways for age-related macular degeneration (AMD). We hypothesized that the relationship between lipids and AMD may also differ according to CS genotype profile. Thus, the objective was to investigate the relationships between lipid-related metabolites and AMD according to CS genotypes. DESIGN Population-based cross-sectional study. PARTICIPANTS A total of 6947 participants from Singapore Epidemiology of Eye Diseases study with complete relevant data were included. METHODS We investigated a total of 32 blood lipid-related metabolites from nuclear magnetic resonance metabolomics data including lipoproteins and their subclasses, cholesterols, glycerides, and phospholipids, as well as 4 CS single nucleotide polymorphisms (SNPs): rs10922109 (complement factor H), rs10033900 (complement factor I), rs116503776 (C2-CFB-SKIV2L), and rs2230199 (C3). We first investigated the associations between AMD and the 32 lipid-related metabolites using multivariable logistic regression models. Then, to investigate whether the effect of lipid-related metabolites on AMD differ according to the CS SNPs, we tested the possible interactions between the CS SNPs and the lipid-related metabolites. MAIN OUTCOME MEASURES Age-related macular degeneration was defined using the Wisconsin grading system. RESULTS Among the 6947 participants, the prevalence of AMD was 6.1%, and the mean age was 58.3 years. First, higher levels of cholesterol in high-density lipoprotein (HDL) and medium and large HDL particles were associated with an increased risk of AMD, and higher levels of serum total triglycerides (TG) and several very-low-density lipoprotein subclass particles were associated with a decreased risk of AMD. Second, these lipids had significant interaction effects on AMD with 2 CS SNPs: rs2230199 and rs116503776 (after correction for multiple testing). For rs2230199, in individuals without risk allele, higher total cholesterol in HDL2 was associated with an increased AMD risk (odds ratio [OR] per standard deviation increase, 1.20; 95% confidence interval (CI), 1.06-1.37; P = 0.005), whereas, in individuals with at least 1 risk allele, higher levels of these particles were associated with a decreased AMD risk (OR, 0.69; 95% CI, 0.45-1.05; P = 0.079). Conversely, for rs116503776, in individuals without risk allele, higher serum total TG were associated with a decreased AMD risk (OR, 0.84; 95% CI, 0.74-0.95; P = 0.005), whereas, in individuals with 2 risk alleles, higher levels of these particles were associated with an increased risk of AMD (OR, 2.3, 95% CI, 0.99-5.39, P = 0.054). CONCLUSIONS Lipid-related metabolites exhibit opposite directions of effects on AMD according to CS genotypes. This indicates that lipid metabolism and CS may have synergistic interplay in the AMD pathogenesis.
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Key Words
- AMD, age-related macular degeneration
- Age-related macular degeneration
- CFH, complement factor H
- CS, complement system
- Complement system
- HDL, high-density lipoprotein
- Lipids
- Metabolites
- NMR, nuclear magnetic resonance
- OR, odds ratio
- RPE, retinal pigment epithelium
- SNP, single nucleotide polymorphism
- TG, triglycerides
- VLDL, very-low–density lipoprotein
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Affiliation(s)
- Ralene Zi Hui Sim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Yih-Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
| | | | - Lei Zhou
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
| | - Xiaomeng Wang
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A∗STAR), Singapore
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
| | - Gemmy Chiu Ming Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Simon Nusinovici
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences Academic Clinical Program (Eye ACP), Duke-NUS Medical School, Singapore
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3
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Liu JD, Gong R, Zhang SY, Zhou ZP, Wu YQ. Beneficial effects of high-density lipoprotein (HDL) on stent biocompatibility and the potential value of HDL infusion therapy following percutaneous coronary intervention. Medicine (Baltimore) 2022; 101:e31724. [PMID: 36397406 PMCID: PMC9666103 DOI: 10.1097/md.0000000000031724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Several epidemiological studies have shown a clear inverse relationship between serum levels of high-density lipoprotein cholesterol (HDL-C) and the risk of atherosclerotic cardiovascular disease (ASCVD), even at low-density lipoprotein cholesterol levels below 70 mg/dL. There is much evidence from basic and clinical studies that higher HDL-C levels are beneficial, whereas lower HDL-C levels are detrimental. Thus, HDL is widely recognized as an essential anti-atherogenic factor that plays a protective role against the development of ASCVD. Percutaneous coronary intervention is an increasingly common treatment choice to improve myocardial perfusion in patients with ASCVD. Although drug-eluting stents have substantially overcome the limitations of conventional bare-metal stents, there are still problems with stent biocompatibility, including delayed re-endothelialization and neoatherosclerosis, which cause stent thrombosis and in-stent restenosis. According to numerous studies, HDL not only protects against the development of atherosclerosis, but also has many anti-inflammatory and vasoprotective properties. Therefore, the use of HDL as a therapeutic target has been met with great interest. Although oral medications have not shown promise, the developed HDL infusions have been tested in clinical trials and have demonstrated viability and reproducibility in increasing the cholesterol efflux capacity and decreasing plasma markers of inflammation. The aim of the present study was to review the effect of HDL on stent biocompatibility in ASCVD patients following implantation and discuss a novel therapeutic direction of HDL infusion therapy that may be a promising candidate as an adjunctive therapy to improve stent biocompatibility following percutaneous coronary intervention.
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Affiliation(s)
- Jian-Di Liu
- Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Ren Gong
- Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Shi-Yuan Zhang
- Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Zhi-Peng Zhou
- Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
| | - Yan-Qing Wu
- Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- * Correspondence: Yan-Qing Wu, Department of Cardiology, The Second Affiliated Hospital of Nanchang University, Minde Road No. 1, Nanchang, Jiangxi 330006, China (e-mail: )
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Kudinov VA, Alekseeva OY, Torkhovskaya TI, Baskaev KK, Artyushev RI, Saburina IN, Markin SS. High-Density Lipoproteins as Homeostatic Nanoparticles of Blood Plasma. Int J Mol Sci 2020; 21:E8737. [PMID: 33228032 PMCID: PMC7699323 DOI: 10.3390/ijms21228737] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/14/2020] [Accepted: 11/15/2020] [Indexed: 02/07/2023] Open
Abstract
It is well known that blood lipoproteins (LPs) are multimolecular complexes of lipids and proteins that play a crucial role in lipid transport. High-density lipoproteins (HDL) are a class of blood plasma LPs that mediate reverse cholesterol transport (RCT)-cholesterol transport from the peripheral tissues to the liver. Due to this ability to promote cholesterol uptake from cell membranes, HDL possess antiatherogenic properties. This function was first observed at the end of the 1970s to the beginning of the 1980s, resulting in high interest in this class of LPs. It was shown that HDL are the prevalent class of LPs in several types of living organisms (from fishes to monkeys) with high resistance to atherosclerosis and cardiovascular disorders. Lately, understanding of the mechanisms of the antiatherogenic properties of HDL has significantly expanded. Besides the contribution to RCT, HDL have been shown to modulate inflammatory processes, blood clotting, and vasomotor responses. These particles also possess antioxidant properties and contribute to immune reactions and intercellular signaling. Herein, we review data on the structure and mechanisms of the pleiotropic biological functions of HDL from the point of view of their evolutionary role and complex dynamic nature.
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Affiliation(s)
- Vasily A. Kudinov
- Laboratory of Cell Biology and Developmental Pathology, FSBSI Institute of General Pathology and Pathophysiology, 125315 Moscow, Russia;
- Experimental Drug Research and Production Department, Institute of Biomedical Chemistry, 119121 Moscow, Russia; (K.K.B.); (R.I.A.)
| | - Olga Yu. Alekseeva
- Cell Physiology Laboratory, Institute of Biomedical Problems, Russian Academy of Sciences, 123007 Moscow, Russia;
- Department of Biochemistry, People’s Friendship University (RUDN University), 117198 Moscow, Russia
| | - Tatiana I. Torkhovskaya
- Laboratory of Phospholipid Transport Systems and Nanomedicines, Institute of Biomedical Chemistry, 119121 Moscow, Russia;
| | - Konstantin K. Baskaev
- Experimental Drug Research and Production Department, Institute of Biomedical Chemistry, 119121 Moscow, Russia; (K.K.B.); (R.I.A.)
| | - Rafael I. Artyushev
- Experimental Drug Research and Production Department, Institute of Biomedical Chemistry, 119121 Moscow, Russia; (K.K.B.); (R.I.A.)
| | - Irina N. Saburina
- Laboratory of Cell Biology and Developmental Pathology, FSBSI Institute of General Pathology and Pathophysiology, 125315 Moscow, Russia;
| | - Sergey S. Markin
- Clinical Research Department, Institute of Biomedical Chemistry, 119121 Moscow, Russia;
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5
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Betzler BK, Rim TH, Sabanayagam C, Cheung CMG, Cheng CY. High-Density Lipoprotein Cholesterol in Age-Related Ocular Diseases. Biomolecules 2020; 10:E645. [PMID: 32331355 PMCID: PMC7226134 DOI: 10.3390/biom10040645] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 12/16/2022] Open
Abstract
There is limited understanding of the specific role of high-density lipoprotein cholesterol (HDL-C) in the development of various age-related ocular diseases, despite it being a common measurable biomarker in lipid profiles. This literature review summarizes current knowledge of the role of HDL-C, if any, in pathogenesis and progression of four age-related ocular diseases, namely age-related macular degeneration (AMD), age-related cataract, glaucoma, and diabetic retinopathy (DR), and will primarily discuss epidemiological and genetic evidence.
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Affiliation(s)
- Bjorn Kaijun Betzler
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore;
| | - Tyler Hyungtaek Rim
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (T.H.R.); (C.S.); (C.M.G.C.)
- Ophthalmology & Visual Sciences Academic Clinical Program (EYE-ACP), Duke-NUS Medical School, Singapore 169857, Singapore
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (T.H.R.); (C.S.); (C.M.G.C.)
- Ophthalmology & Visual Sciences Academic Clinical Program (EYE-ACP), Duke-NUS Medical School, Singapore 169857, Singapore
| | - Chui Ming Gemmy Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (T.H.R.); (C.S.); (C.M.G.C.)
- Ophthalmology & Visual Sciences Academic Clinical Program (EYE-ACP), Duke-NUS Medical School, Singapore 169857, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 169856, Singapore; (T.H.R.); (C.S.); (C.M.G.C.)
- Ophthalmology & Visual Sciences Academic Clinical Program (EYE-ACP), Duke-NUS Medical School, Singapore 169857, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
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6
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Zhang Y, Gordon SM, Xi H, Choi S, Paz MA, Sun R, Yang W, Saredy J, Khan M, Remaley AT, Wang JF, Yang X, Wang H. HDL subclass proteomic analysis and functional implication of protein dynamic change during HDL maturation. Redox Biol 2019; 24:101222. [PMID: 31153037 PMCID: PMC6541906 DOI: 10.1016/j.redox.2019.101222] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/09/2019] [Accepted: 05/14/2019] [Indexed: 01/27/2023] Open
Abstract
Recent clinical trials reported that increasing high-density lipoprotein-cholesterol (HDL-C) levels does not improve cardiovascular outcomes. We hypothesize that HDL proteome dynamics determine HDL cardioprotective functions. In this study, we characterized proteome profiles in HDL subclasses and established their functional connection. Mouse plasma was fractionized by fast protein liquid chromatography, examined for protein, cholesterial, phospholipid and trigliceride content. Small, medium and large (S/M/L)-HDL subclasseses were collected for proteomic analysis by mass spectrometry. Fifty-one HDL proteins (39 in S-HDL, 27 in M-HDL and 29 in L-HDL) were identified and grouped into 4 functional categories (lipid metabolism, immune response, coagulation, and others). Eleven HDL common proteins were identified in all HDL subclasses. Sixteen, 3 and 7 proteins were found only in S-HDL, M-HDL and L-HDL, respectively. We established HDL protein dynamic distribution in S/M/L-HDL and developed a model of protein composition change during HDL maturation. We found that cholesterol efflux and immune response are essential functions for all HDL particles, and amino acid metabolism is a special function of S-HDL, whereas anti-coagulation is special for M-HDL. Pon1 is recruited into M/L-HDL to provide its antioxidative function. ApoE is incorporated into L-HDL to optimize its cholesterial clearance function. Next, we acquired HDL proteome data from Pubmed and identified 12 replicated proteins in human and mouse HDL particle. Finally, we extracted 3 shared top moleccular pathways (LXR/RXR, FXR/RXR and acute phase response) for all HDL particles and 5 top disease/bio-functions differentially related to S/M/L-HDL subclasses, and presented one top net works for each HDL subclass. We conclude that beside their essencial functions of cholesterol efflux and immune response, HDL aquired antioxidative and cholesterol clearance functions by recruiting Pon1 and ApoE during HDL maturation.
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Affiliation(s)
- Yuling Zhang
- Cardiovascular Medicine Department, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China; Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, Guangzhou, China
| | - Scott M Gordon
- Cardiopulmonary Branch, NHLBI, National Institutes of Health, Building 10 Room 2C433, Bethesda, MD, 20892, USA; Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, 40536, USA
| | - Hang Xi
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Seungbum Choi
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Merlin Abner Paz
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Runlu Sun
- Cardiovascular Medicine Department, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, Guangzhou, China
| | - William Yang
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Jason Saredy
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Mohsin Khan
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Alan Thomas Remaley
- Cardiopulmonary Branch, NHLBI, National Institutes of Health, Building 10 Room 2C433, Bethesda, MD, 20892, USA
| | - Jing-Feng Wang
- Cardiovascular Medicine Department, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China; Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, Guangzhou, China
| | - Xiaofeng Yang
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| | - Hong Wang
- Centers for Metabolic & Cardiovascular Research, Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, 19140, USA.
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7
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Colijn JM, den Hollander AI, Demirkan A, Cougnard-Grégoire A, Verzijden T, Kersten E, Meester-Smoor MA, Merle BMJ, Papageorgiou G, Ahmad S, Mulder MT, Costa MA, Benlian P, Bertelsen G, Bron AM, Claes B, Creuzot-Garcher C, Erke MG, Fauser S, Foster PJ, Hammond CJ, Hense HW, Hoyng CB, Khawaja AP, Korobelnik JF, Piermarocchi S, Segato T, Silva R, Souied EH, Williams KM, van Duijn CM, Delcourt C, Klaver CCW. Increased High-Density Lipoprotein Levels Associated with Age-Related Macular Degeneration: Evidence from the EYE-RISK and European Eye Epidemiology Consortia. Ophthalmology 2019; 126:393-406. [PMID: 30315903 DOI: 10.1016/j.ophtha.2018.09.045] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 09/01/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset. DESIGN Pooled analysis of cross-sectional data. PARTICIPANTS Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data. METHODS AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations. MAIN OUTCOME MEASURES AMD features and stage; lipid measurements. RESULTS HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14-1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91-0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10-1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10-7), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10-6 and P = 1.6 × 10-4). CONCLUSIONS Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered.
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Affiliation(s)
- Johanna M Colijn
- Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ayse Demirkan
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Audrey Cougnard-Grégoire
- Bordeaux Population Health Research Center, UMR 1219, University of Bordeaux, Inserm, Bordeaux, France
| | - Timo Verzijden
- Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Eveline Kersten
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Magda A Meester-Smoor
- Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Benedicte M J Merle
- Bordeaux Population Health Research Center, UMR 1219, University of Bordeaux, Inserm, Bordeaux, France
| | - Grigorios Papageorgiou
- Department of Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Shahzad Ahmad
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Monique T Mulder
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Miguel Angelo Costa
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal
| | - Pascale Benlian
- Univ. Lille, CHU Lille, UMR 8199 - EGID - European Genomic Institute for Diabetes, Lille, France
| | - Geir Bertelsen
- Department of Community Medicine, UiT, The Arctic University of Norway, Tromsø, Norway; Department of Ophthalmology, University Hospital of North Norway, Tromsø, Norway
| | - Alain M Bron
- Department of Ophthalmology, University Hospital, Eye and Nutrition Research Group, Dijon, France
| | - Birte Claes
- Institute of Epidemiology and Social Medicine, University of Muenster, Germany
| | | | - Maja Gran Erke
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Sascha Fauser
- Department of Ophthalmology, University Hospital Cologne, Cologne, Germany; Hoffmann-La Roche AG, Basel, Switzerland
| | - Paul J Foster
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; Integrative Epidemiology, UCL Institute of Ophthalmology, London, United Kingdom
| | - Christopher J Hammond
- Section of Academic Ophthalmology, School of Life Course Sciences, King's College London, St. Thomas' Hospital, London, United Kingdom; Department of Twin Research & Genetic Epidemiology, King's College London, St. Thomas' Hospital, London, United Kingdom
| | - Hans-Werner Hense
- Institute of Epidemiology and Social Medicine, University of Muenster, Germany
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anthony P Khawaja
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Jean-Francois Korobelnik
- Bordeaux Population Health Research Center, UMR 1219, University of Bordeaux, Inserm, Bordeaux, France; Service d'Ophtalmologie, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | | | - Tatiana Segato
- Department of Ophthalmology, University of Padova, Padova, Italy
| | - Rufino Silva
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal; Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal; Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Eric H Souied
- Department of Ophthalmology, Centre Hospitalier Intercommunal de Creteil, University Paris Est Creteil, Creteil, France
| | - Katie M Williams
- Section of Academic Ophthalmology, School of Life Course Sciences, King's College London, St. Thomas' Hospital, London, United Kingdom; Department of Twin Research & Genetic Epidemiology, King's College London, St. Thomas' Hospital, London, United Kingdom
| | - Cornelia M van Duijn
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Cécile Delcourt
- Bordeaux Population Health Research Center, UMR 1219, University of Bordeaux, Inserm, Bordeaux, France
| | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
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8
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van Leeuwen EM, Emri E, Merle BMJ, Colijn JM, Kersten E, Cougnard-Gregoire A, Dammeier S, Meester-Smoor M, Pool FM, de Jong EK, Delcourt C, Rodrigez-Bocanegra E, Biarnés M, Luthert PJ, Ueffing M, Klaver CCW, Nogoceke E, den Hollander AI, Lengyel I. A new perspective on lipid research in age-related macular degeneration. Prog Retin Eye Res 2018; 67:56-86. [PMID: 29729972 DOI: 10.1016/j.preteyeres.2018.04.006] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/25/2018] [Accepted: 04/30/2018] [Indexed: 12/15/2022]
Abstract
There is an urgency to find new treatment strategies that could prevent or delay the onset or progression of AMD. Different classes of lipids and lipoproteins metabolism genes have been associated with AMD in a multiple ways, but despite the ever-increasing knowledge base, we still do not understand fully how circulating lipids or local lipid metabolism contribute to AMD. It is essential to clarify whether dietary lipids, systemic or local lipoprotein metabolismtrafficking of lipids in the retina should be targeted in the disease. In this article, we critically evaluate what has been reported in the literature and identify new directions needed to bring about a significant advance in our understanding of the role for lipids in AMD. This may help to develop potential new treatment strategies through targeting the lipid homeostasis.
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Affiliation(s)
- Elisabeth M van Leeuwen
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Eszter Emri
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Benedicte M J Merle
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000, Bordeaux, France
| | - Johanna M Colijn
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Eveline Kersten
- Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Audrey Cougnard-Gregoire
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000, Bordeaux, France
| | - Sascha Dammeier
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Germany
| | - Magda Meester-Smoor
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Eiko K de Jong
- Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Cécile Delcourt
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000, Bordeaux, France
| | | | | | | | - Marius Ueffing
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Germany
| | - Caroline C W Klaver
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Everson Nogoceke
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands; Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Imre Lengyel
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom.
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9
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Dysfunctional High-Density Lipoprotein: An Innovative Target for Proteomics and Lipidomics. CHOLESTEROL 2015; 2015:296417. [PMID: 26634153 PMCID: PMC4655037 DOI: 10.1155/2015/296417] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 10/12/2015] [Accepted: 10/12/2015] [Indexed: 02/02/2023]
Abstract
High-Density Lipoprotein-Cholesterol (HDL-C) is regarded as an important protective factor against cardiovascular disease, with abundant evidence of an inverse relationship between its serum levels and risk of cardiovascular disease, as well as various antiatherogenic, antioxidant, and anti-inflammatory properties. Nevertheless, observations of hereditary syndromes featuring scant HDL-C concentration in absence of premature atherosclerotic disease suggest HDL-C levels may not be the best predictor of cardiovascular disease. Indeed, the beneficial effects of HDL may not depend solely on their concentration, but also on their quality. Distinct subfractions of this lipoprotein appear to be constituted by specific protein-lipid conglomerates necessary for different physiologic and pathophysiologic functions. However, in a chronic inflammatory microenvironment, diverse components of the HDL proteome and lipid core suffer alterations, which propel a shift towards a dysfunctional state, where HDL-C becomes proatherogenic, prooxidant, and proinflammatory. This heterogeneity highlights the need for further specialized molecular studies in this aspect, in order to achieve a better understanding of this dysfunctional state; with an emphasis on the potential role for proteomics and lipidomics as valuable methods in the search of novel therapeutic approaches for cardiovascular disease.
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10
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Huggins C, Charolidi N, Cockerill GW. Cholesteryl Ester Transfer Protein Inhibitors - Future Soon to be REVEALed. Eur Cardiol 2015; 10:64-67. [PMID: 30310426 DOI: 10.15420/ecr.2015.10.01.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Reduction of the remaining residual cardiovascular risk is a clinical unmet need currently being addressed through a combination of further reduction of plasma concentrations of low-density lipoproteins (LDLs) and increasing plasma concentrations of high-density lipoproteins (HDLs). This brief review sets out the so-called HDL hypothesis and summarises the clinical results of the family of drugs, which function to raise plasma HDL concentration through inhibition of cholesteryl ester transfer proteins (CEPT).
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11
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Niyonzima N, Samstad EO, Aune MH, Ryan L, Bakke SS, Rokstad AM, Wright SD, Damås JK, Mollnes TE, Latz E, Espevik T. Reconstituted High-Density Lipoprotein Attenuates Cholesterol Crystal-Induced Inflammatory Responses by Reducing Complement Activation. THE JOURNAL OF IMMUNOLOGY 2015; 195:257-64. [PMID: 26026058 DOI: 10.4049/jimmunol.1403044] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 04/23/2015] [Indexed: 11/19/2022]
Abstract
Chronic inflammation of the arterial wall is a key element in the development of atherosclerosis, and cholesterol crystals (CC) that accumulate in plaques are associated with initiation and progression of the disease. We recently revealed a link between the complement system and CC-induced inflammasome caspase-1 activation, showing that the complement system is a key trigger in CC-induced inflammation. HDL exhibits cardioprotective and anti-inflammatory properties thought to explain its inverse correlation to cardiovascular risk. In this study, we sought to determine the effect of reconstituted HDL (rHDL) on CC-induced inflammation in a human whole blood model. rHDL bound to CC and inhibited the CC-induced complement activation as measured by soluble terminal C5b-9 formation and C3c deposition on the CC surface. rHDL attenuated the amount of CC-induced complement receptor 3 (CD11b/CD18) expression on monocytes and granulocytes, as well as reactive oxygen species generation. Moreover, addition of CC to whole blood resulted in release of proinflammatory cytokines that were inhibited by rHDL. Our results support and extend the notion that CC are potent triggers of inflammation, and that rHDL may have a beneficial role in controlling the CC-induced inflammatory responses by inhibiting complement deposition on the crystals.
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Affiliation(s)
- Nathalie Niyonzima
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Eivind O Samstad
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Department of Medicine, Ålesund Hospital, Ålesund 6026, Norway
| | - Marie H Aune
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Liv Ryan
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Siril S Bakke
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Anne Mari Rokstad
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Central Norway Regional Health Authority, Trondheim N-7501, Norway
| | - Samuel D Wright
- Cardiovascular Therapeutics, CSL Behring, King of Prussia, PA 19406
| | - Jan K Damås
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Tom E Mollnes
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Department of Immunology, Oslo University Hospital, Oslo N-0027, Norway; K.G. Jebsen Inflammatory Research Centre, University of Oslo, Oslo N-0027, Norway; Research Laboratory, Nordland Hospital, Bodø N-8092, Norway; K.G. Jebsen Thrombosis Research and Expertise Center, University of Tromsø, Tromsø N-9037, Norway; and
| | - Eicke Latz
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Biomedical Center, Institute of Innate Immunity, University of Bonn, Bonn 53127, Germany
| | - Terje Espevik
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, N-7491 Trondheim, Norway;
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12
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Shah AS, Tan L, Long JL, Davidson WS. Proteomic diversity of high density lipoproteins: our emerging understanding of its importance in lipid transport and beyond. J Lipid Res 2013; 54:2575-85. [PMID: 23434634 PMCID: PMC3770071 DOI: 10.1194/jlr.r035725] [Citation(s) in RCA: 276] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/18/2013] [Indexed: 01/09/2023] Open
Abstract
Recent applications of mass spectrometry technology have dramatically increased our understanding of the proteomic diversity of high density lipoproteins (HDL). Depending on the method of HDL isolation, upwards of 85 proteins have been identified, and the list continues to grow. In addition to proteins consistent with traditionally accepted roles in lipid transport, HDL carries surprising constituents, such as members of the complement pathway, protease inhibitors involved in hemostasis, acute-phase response proteins, immune function mediators, and even metal-binding proteins. This compositional diversity fits well with hundreds of studies demonstrating a wide functional pleiotrophy, including roles in lipid transport, oxidation, inflammation, hemostasis, and immunity. This review summarizes the progression of our understanding of HDL proteomic complexity and points out key experimental observations that reinforce the functional diversity of HDL. The possibility of specific HDL subspecies with distinct functions, the evidence supporting this concept, and some of the best examples of experimentally defined HDL subspecies are also discussed. Finally, key challenges facing the field are highlighted, particularly the need to identify and define the function of HDL subspecies to better inform attempts to pharmacologically manipulate HDL for the benefit of cardiovascular disease and possibly other maladies.
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Affiliation(s)
- Amy S. Shah
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Lirong Tan
- Division of Biomedical Informatics, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH; and
| | - Jason Lu Long
- Division of Biomedical Informatics, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH; and
| | - W. Sean Davidson
- Center for Lipid and Arteriosclerosis Science, University of Cincinnati, Cincinnati, OH
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13
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High-density lipoproteins and the immune system. J Lipids 2013; 2013:684903. [PMID: 23431458 PMCID: PMC3572698 DOI: 10.1155/2013/684903] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 12/28/2012] [Accepted: 12/31/2012] [Indexed: 12/16/2022] Open
Abstract
High-density lipoprotein (HDL) plays a major role in vasodilation and in the reduction of low-density lipoprotein (LDL) oxidation, inflammation, apoptosis, thrombosis, and infection; however, HDL is now less functional in these roles under certain conditions. This paper focuses on HDL, its anti-inflammation behavior, and the mechanisms by which HDL interacts with components of the innate and adaptive immune systems. Genome-wide association studies (GWAS) and proteomic studies have elucidated important molecules involved in the interaction between HDL and the immune system. An understanding of these mechanisms is expected to be useful for the prevention and treatment of chronic inflammation due to metabolic syndrome, atherosclerosis, or various autoimmune diseases.
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14
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Abstract
PURPOSE OF REVIEW HDLs possess several physiological activities that may explain their antiatherosclerotic properties. Among them, the most relevant is the ability of HDL to promote the efflux of excess cholesterol from peripheral tissues to the liver for excretion. RECENT FINDINGS The ability of HDL to promote cholesterol efflux results also in the modulation of a series of responses in the immune cells involved in atherosclerosis, including monocyte-macrophages, B and T lymphocytes. HDL also acts as a reservoir for a number of biologically active substances that may impact the immune system, and as the HDL composition varies to a large extent during inflammation. SUMMARY The understanding of how these interactions take place and how biologically active substances can be delivered to relevant targets during atherogenesis is of great interest and may provide a better understanding for the role of HDL in atherogenesis.
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Affiliation(s)
- Giuseppe D Norata
- Department of Pharmacological Sciences, Università degli Studi di Milano, Centro SISA per lo Studio dell'Aterosclerosi, Ospedale Bassini, Cinisello Balsamo, Milan, Italy
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15
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Biedzka-Sarek M, Metso J, Kateifides A, Meri T, Jokiranta TS, Muszyński A, Radziejewska-Lebrecht J, Zannis V, Skurnik M, Jauhiainen M. Apolipoprotein A-I exerts bactericidal activity against Yersinia enterocolitica serotype O:3. J Biol Chem 2011; 286:38211-38219. [PMID: 21896489 DOI: 10.1074/jbc.m111.249482] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein A-I (apoA-I), the main protein component of high density lipoprotein (HDL), is well recognized for its antiatherogenic, antioxidant, and antiinflammatory properties. Here, we report a novel role for apoA-I as a host defense molecule that contributes to the complement-mediated killing of an important gastrointestinal pathogen, Gram-negative bacterium Yersinia enterocolitica. We specifically show that the C-terminal domain of apoA-I is the effector site providing the bactericidal activity. Although the presence of the lipopolysaccharide O-antigen on the bacterial surface is absolutely required for apoA-I to kill the bacteria, apoA-I does not interact with the bacteria directly. To the contrary, exposure of the bacteria by serum proteins triggers apoA-I deposition on the bacterial surface. As our data show that both purified lipid-free and HDL-associated apoA-I displays anti-bacterial potential, apoA-I mimetic peptides may be a promising therapeutic agent for the treatment of certain Gram-negative infections.
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Affiliation(s)
- Marta Biedzka-Sarek
- Department of Chronic Disease Prevention, Public Health Genomics Research Unit, National Institute for Health and Welfare, and Institute for Molecular Medicine Finland (FIMM), 00290 Helsinki, Finland.
| | - Jari Metso
- Department of Chronic Disease Prevention, Public Health Genomics Research Unit, National Institute for Health and Welfare, and Institute for Molecular Medicine Finland (FIMM), 00290 Helsinki, Finland
| | - Andreas Kateifides
- Department of Molecular Genetics, Boston University Medical Center, Boston, Massachusetts 02118
| | - Taru Meri
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, 00014 Helsinki, Finland; Department of Laboratory Diagnostics, Helsinki University Central Hospital, 00290 Helsinki, Finland
| | - T Sakari Jokiranta
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, 00014 Helsinki, Finland
| | - Artur Muszyński
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | | | - Vassilis Zannis
- Department of Molecular Genetics, Boston University Medical Center, Boston, Massachusetts 02118
| | - Mikael Skurnik
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, 00014 Helsinki, Finland; Department of Laboratory Diagnostics, Helsinki University Central Hospital, 00290 Helsinki, Finland
| | - Matti Jauhiainen
- Department of Chronic Disease Prevention, Public Health Genomics Research Unit, National Institute for Health and Welfare, and Institute for Molecular Medicine Finland (FIMM), 00290 Helsinki, Finland
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16
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Emerging role of high density lipoproteins as a player in the immune system. Atherosclerosis 2011; 220:11-21. [PMID: 21783193 DOI: 10.1016/j.atherosclerosis.2011.06.045] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/08/2011] [Accepted: 06/24/2011] [Indexed: 11/23/2022]
Abstract
High density lipoproteins (HDL) possess a number of physiological activities. The most studied and, perhaps, better understood is the ability of HDL to promote excess cholesterol efflux from peripheral tissues and transport to the liver for excretion, a mechanism believed to confer protection against atherosclerotic cardiovascular disease. The ability of HDL to modulate cholesterol bioavailability in the lipid rafts, membrane microdomains enriched in glycosphingolipids and cholesterol, is evolutionary conserved and affects the properties of cells involved in the innate and adaptive immune response, tuning inflammatory response and antigen presentation functions in macrophages as well as B and T cell activation. Also sphingosine-1 phosphate (S1P), a major active sphingolipid carried by HDL, is of relevance in the pathogenesis of several immuno-inflammatory disorders through the modulation of macrophage and lymphocyte functions. Furthermore, HDL influence the humoral innate immunity by modulating the activation of the complement system and the expression of pentraxin 3 (PTX3). Finally, in humans, HDL levels and functions are altered in several immune-mediated disorders, such as rheumatoid arthritis, systemic lupus eritematosus, Crohn's disease and multiple sclerosis as well as during inflammatory responses. Altogether these observations suggest that the effects of HDL in immunity could be related, to either the ability of HDL to modulate cholesterol content in immune cell lipid rafts and to their role as reservoir for several biologically active substances that may impact the immune system.
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17
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Abstract
Age-related macular degeneration (AMD) is an inflammatory disease, which causes visual impairment and blindness in older people. The proteins of the complement system are central to the development of this disease. Local and systemic inflammation in AMD are mediated by the deregulated action of the alternative pathway of the complement system. Variants in complement system genes alter an individual's risk of developing AMD. Recent studies have shown how some risk-associated genetic variants alter the function of the complement system. In this review, we describe the evolution of the complement system and bring together recent research to form a picture of how changes in complement system genes and proteins affect the function of the complement cascade, and how this affects the development of AMD. We discuss the application of this knowledge to prevention and possible future treatments of AMD.
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18
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Hoofnagle AN, Heinecke JW. Lipoproteomics: using mass spectrometry-based proteomics to explore the assembly, structure, and function of lipoproteins. J Lipid Res 2010; 50:1967-75. [PMID: 19738003 DOI: 10.1194/jlr.r900015-jlr200] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Lipoproteins are centrally important in lipid transport, fuel metabolism, and cardiovascular disease. The prototypic lipoprotein has an outer shell of amphipathic lipids and proteins that solubilizes a hydrophobic lipid core. Lipoprotein-associated proteins have classically been viewed as structural elements and factors important in lipid metabolism. Recent mass spectrometric analyses reveal that the protein cargo of lipoproteins is much more diverse than previously appreciated, raising the possibility that lipoproteins play previously unsuspected roles in host defense mechanisms and inflammation. They further suggest that lipoprotein-associated proteins can identify humans at increased risk of cardiovascular disease. Here, we summarize recent developments in lipoproteomics, the proteomic analysis of lipoproteins. We also discuss the promises and challenges this powerful analytical strategy offers for expanding our understanding of the biology and structures of lipoproteins.
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Affiliation(s)
- Andrew N Hoofnagle
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA.
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19
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Hoofnagle AN, Wu M, Gosmanova AK, Becker JO, Wijsman EM, Brunzell JD, Kahn SE, Knopp RH, Lyons TJ, Heinecke JW. Low clusterin levels in high-density lipoprotein associate with insulin resistance, obesity, and dyslipoproteinemia. Arterioscler Thromb Vasc Biol 2010; 30:2528-34. [PMID: 20847305 DOI: 10.1161/atvbaha.110.212894] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine whether obesity and insulin resistance associate with changes in the protein content of high-density lipoprotein (HDL) in 2 different groups of men by using targeted proteomics. METHODS AND RESULTS Insulin resistance and obesity are hallmarks of type 2 diabetes mellitus and the metabolic syndrome, which confer an increased risk of cardiovascular disease. Recent studies suggest that the protein cargo of HDL makes important contributions to the lipoprotein's cardioprotective effects. In a discovery study, we used isotope dilution mass spectrometry to quantify the relative concentrations of 5 proteins previously implicated in HDL's cardioprotective effects in 3 groups of healthy subjects: lean insulin-sensitive, lean insulin-resistant, and obese insulin-resistant individuals. We validated our findings in a different group of subjects. The clusterin concentration in HDL strongly and negatively associated with insulin resistance and body mass index in both populations. HDL clusterin levels were lower in subjects with low HDL and high triglycerides, key components of the metabolic syndrome. There was an inverse correlation between clusterin levels in HDL and very-low-density lipoprotein/low-density lipoprotein. CONCLUSIONS Clusterin levels in HDL are lower in men with reduced insulin sensitivity, higher body mass index, and an unfavorable lipid profile. Our observations raise the possibility that clusterin depletion contributes to the loss of HDL's cardioprotective properties.
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Affiliation(s)
- Andrew N Hoofnagle
- Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.
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20
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von Eckardstein A, Rohrer L. Transendothelial lipoprotein transport and regulation of endothelial permeability and integrity by lipoproteins. Curr Opin Lipidol 2009; 20:197-205. [PMID: 19395962 DOI: 10.1097/mol.0b013e32832afd63] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW Previously, the endothelium was considered as a passive exchange barrier of lipoproteins between plasma and extravascular tissues. This dogma is challenged by recent findings on a dual relationship between lipoproteins and endothelial permeability. RECENT FINDINGS LDL and HDL as well as apolipoprotein A-I pass the intact endothelium through transcytosis by processes, which involve caveolin-1, the LDL-receptor, ATP-binding cassette transporters A1 and G1 or scavenger receptor BI. Moreover, HDL help the endothelium to maintain structural integrity and hence selective permeability for biomolecules by keeping interendothelial junctions closed, by inhibiting endothelial cell apoptosis and by stimulating endothelial proliferation, migration and tube formation as well as the recruitment and differentiation of endothelial progenitor cells in damaged parts of the endothelium. Both apolipoprotein A-I and sphingosin-1-phosphate mediate many of the protective effects of HDL on the endothelium by interacting with endothelial scavenger receptor BI and sphingosin-1-phosphate receptors, respectively, and by activating intracellular signalling cascades, including the small G protein Rac, src-kinase, phosphoinositol 3 kinase, protein kinase B (Akt) and mitogen-activated protein kinases. SUMMARY The endothelium actively controls the trafficking of lipoproteins between intravascular and extravascular compartments. In addition, lipoproteins affect the integrity and permeability of the endothelium.
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Affiliation(s)
- Arnold von Eckardstein
- Institute of Clinical Chemistry and Zurich Centre for Integrative Human Physiology, University Hospital and University of Zurich, Zurich, Switzerland.
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21
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Norata GD, Catapano AL. Molecular mechanisms responsible for the antiinflammatory and protective effect of HDL on the endothelium. Vasc Health Risk Manag 2007; 1:119-29. [PMID: 17315398 PMCID: PMC1993938 DOI: 10.2147/vhrm.1.2.119.64083] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In addition to their role in reverse cholesterol transport, high-density lipoproteins (HDL) exert several beneficial effects, including the prevention and correction of endothelial dysfunction. HDL promote endothelium proliferation and diminish endothelial apoptosis; they play a key role in vasorelaxation by increasing the release of nitric oxide and prostacyclin through the induction of the expression and the activity of endothelial nitric oxide synthase and the coupling of cyclooxygenase 2 and prostacyclin synthase. In addition, HDL affect coagulation, fibrynolisis, platelet adhesion, adhesion molecules, and protease expression, and they exert antioxidant activity. These effects are achieved at the gene expression level and are dependent on the activation of several intracellular signaling pathways, including PI3K/Akt, ERK1/2, PKC, and p38MAPK. The complexity of the signaling pathways modulated by HDL reflects the different effects of the components of this class of lipoproteins such as apolipoproteins or lipids on endothelial cell gene expression and the subsequent modulation of endothelial function observed. The in vivo relevance of these findings to endothelial recovery during physiological or pathological conditions remains to be addressed; nevertheless, the results of clinical studies with synthetic HDL, ApoA-I mimetics, and drugs that are becoming available that selectively affect HDL plasma levels and biological functions support the importance of the correction of endothelial function by HDL.
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22
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Norata GD, Catapano AL. Molecular Mechanisms Responsible for the Anti-Inflammatory and Protective Effect of High-Density Lipoprotein on the Endothelium. High Blood Press Cardiovasc Prev 2007. [DOI: 10.2165/00151642-200714010-00004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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23
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Reverse cholesterol transport. COR ET VASA 2006. [DOI: 10.33678/cor.2006.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Pasqui AL, Puccetti L, Di Renzo M, Bruni F, Camarri A, Palazzuoli A, Biagi F, Servi M, Bischeri D, Auteri A, Pastorelli M. Structural and functional abnormality of systemic microvessels in cardiac syndrome X. Nutr Metab Cardiovasc Dis 2005; 15:56-64. [PMID: 15871852 DOI: 10.1016/j.numecd.2004.05.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Accepted: 05/04/2004] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIM Microvascular damage of coronary bed has been considered the main pathogenetic factor of cardiac syndrome X (chest pain, exercise-induced ischemic ST-segment changes and angiographically normal coronary arteries). Previous studies have demonstrated that vascular abnormalities are not confined to the heart, suggesting a peripheral vascular dysfunction. On the hypothesis of a generalized microvascular disturbance in cardiac syndrome X, we performed a morphologic and functional study of systemic microcirculation in patients with syndrome X compared to normal subjects. METHODS AND RESULTS Microvessels were evaluated with intravital videocapillaroscopy (VCP) executed in peripheral and conjunctival observation sites which explore micro and paramicrocirculation; biohumoral study included markers of inflammation and of endothelial function, coagulative-fibrinolytic system and lipid metabolism. Videocapillaroscopy showed several morphologic changes (present in high percent of patients with syndrome X and not in controls) and significant quantitative alterations (capillary density, granular flow score, alterations of vessel profile, length of capillary loop branches and of arteriole/venule diameter) which indicated a severe alteration of whole vessel structure and an important rearrangement of microvascular disposition. In a similar way, the humoral study showed some significant changes of endothelial (vWF, ICAM-1, E-sel, PAI-1), inflammatory (C-reactive protein (CRP), fibrinogen) and metabolic factors (HDL-chol) which are commonly associated with inflammatory response. CONCLUSIONS We conclude that patients with cardiac syndrome X exhibited some structural and functional alterations of systemic microvasculature; the pattern is similar to that detected in systemic inflammatory diseases and suggests a vascular lesion of inflammatory type. The same changes could be operating also in coronary microvessels of patients with syndrome X.
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Affiliation(s)
- A L Pasqui
- Department of Clinical Medicine and Immunology, Internal Medicine Division, University of Siena, Italy.
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25
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Hersberger M, von Eckardstein A. Low high-density lipoprotein cholesterol: physiological background, clinical importance and drug treatment. Drugs 2004; 63:1907-45. [PMID: 12930163 DOI: 10.2165/00003495-200363180-00003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Low high-density lipoprotein (HDL) cholesterol is an important risk factor for coronary heart disease (CHD). In vitro, HDL exerts several potentially anti-atherogenic activities. HDLs mediate the reverse cholesterol transport (RCT) from peripheral cells to the liver, inhibit oxidation of low-density lipoprotein (LDL), adhesion of monocytes to the endothelium, apoptosis of vascular endothelial and smooth muscle cells and platelet activation, and stimulate the endothelial secretion of vasoactive substances as well as smooth muscle cell proliferation. Hence, raising HDL-cholesterol levels has become an interesting target for anti-atherosclerotic drug therapy. Levels of HDL cholesterol and the composition of HDL subclasses in plasma are regulated by apolipoproteins, lipolytic enzymes, lipid transfer proteins, receptors and cellular transporters. The interplay of these factors leads to RCT and determines the composition and, thereby, the anti-atherogenic properties of HDL. Several inborn errors of metabolism, as well as genetic animal models, are characterised by both elevated HDL cholesterol and increased rather than decreased cardiovascular risk. These findings suggest that the mechanism of HDL modification rather than simply increasing HDL cholesterol determine the efficacy of anti-atherosclerotic drug therapy. In several controlled and prospective intervention studies, patients with low HDL cholesterol and additional risk factors benefited from treatment with fibric acid derivatives (fibrates) or HMG-CoA reductase inhibitors (statins). However, only in some trials was prevention of coronary events in patients with low HDL cholesterol and hypertriglyceridaemia related to an increase in HDL cholesterol. We discuss the clinical and metabolic effects of fibrates, statins, nicotinic acid and sex steroids, and present novel therapeutic strategies that show promise in modifying HDL metabolism. In conclusion, HDL-cholesterol levels increase only moderately after treatment with currently available drugs and do not necessarily correlate with the functionality of HDL. Therefore, the anti-atherosclerotic therapy of high-risk cardiovascular patients should currently be focused on the correction of other risk factors present besides low HDL cholesterol. However, modification of HDL metabolism and improvement of RCT remain an attractive target for the development of new regimens of anti-atherogenic drug therapy.
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Affiliation(s)
- Martin Hersberger
- Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
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26
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Orren A, O'Hara AM, Morgan BP, Moran AP, Würzner R. An abnormal but functionally active complement component C9 protein found in an Irish family with subtotal C9 deficiency. Immunology 2003; 108:384-90. [PMID: 12603605 PMCID: PMC1782909 DOI: 10.1046/j.1365-2567.2003.01587.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two independently segregating C9 genetic defects have previously been reported in two siblings in an Irish family with subtotal C9 deficiency. One defect would lead to an abnormal C9 protein, with replacement of a cysteine by a glycine (C98G). The second defect is a premature stop codon at amino acid 406 which would lead to a truncated C9. However, at least one of two abnormal proteins was present in the circulation of the proband at 0.2% of normal C9 concentration. In this study, the abnormal protein was shown to have a molecular weight approximately equal to that of normal C9, and to carry the binding site for monoclonal antibody (mAb) Mc42 which is known to react with an epitope at amino acid positions 412-426, distal to 406. Therefore, the subtotal C9 protein carries the C98G defect. The protein was incorporated into the terminal complement complex, and was active in haemolytic, bactericidal and lipopolysaccharide release assays. A quantitative haemolytic assay indicated even slightly greater haemolytic efficiency than normal C9. Epitope mapping with six antihuman C9 mAbs showed the abnormal protein to react to these antibodies in the same way as normal C9. However, none of these mAbs have epitopes within the lipoprotein receptor A module, where the C98G defect is located. The role of this region in C9 functionality is still unclear. In conclusion, we have shown that the lack of a cysteine led to the production of a protein present in the circulation at very much reduced levels, but which was fully functionally active.
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Affiliation(s)
- Ann Orren
- Laboratory of Molecular Biochemistry, Department of Microbiology, National University of Ireland, Galway, Ireland
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27
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Furlaneto CJ, Ribeiro FP, Hatanaka E, Souza GM, Cassatella MA, Campa A. Apolipoproteins A-I and A-II downregulate neutrophil functions. Lipids 2002; 37:925-8. [PMID: 12458630 DOI: 10.1007/s11745-002-0981-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This work reports the effect of the apolipoproteins A-I and A-II (apoA-I and apoA-II) on the release of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-8, and IL-1 receptor antagonist (IL-1Ra) and on the oxidative burst of human neutrophils. By themselves, apoA-I and apoA-II do not affect the basal liberation of these cytokines, whereas apoA-I affects the release of IL-1beta from lipopolysaccharide (LPS)-stimulated neutrophils and apoA-II affects IL-8 released from LPS-stimulated neutrophils. ApoA-II also decreases the production of IL-8 released by neutrophils stimulated with the acute phase apolipoprotein serum amyloid A. Both apoA-I and apoA-II exerted approximately 30% inhibition on the oxidative burst of neutrophils stimulated by opsonized zymosan, as revealed by the luminol-enhanced chemiluminescence assay. These findings give additional support to the idea that the role of human plasma lipoproteins and apolipoproteins goes beyond their function in lipid transport and metabolism. HDL apolipoproteins appear to be a class of mediators that can participate in the regulation of the activity of neutrophils.
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Affiliation(s)
- Cristiane Jaciara Furlaneto
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, CEP 05508-900 São Paulo, Brazil
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28
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Nofer JR, Kehrel B, Fobker M, Levkau B, Assmann G, von Eckardstein A. HDL and arteriosclerosis: beyond reverse cholesterol transport. Atherosclerosis 2002; 161:1-16. [PMID: 11882312 DOI: 10.1016/s0021-9150(01)00651-7] [Citation(s) in RCA: 432] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The inverse correlation between serum levels of high density lipoprotein (HDL) cholesterol and the risk of coronary heart disease, the protection of susceptible animals from atherosclerosis by transgenic manipulation of HDL metabolism, and several potentially anti-atherogenic in vitro-properties have made HDL metabolism an interesting target for pharmacological intervention in atheroslcerosis. We have previously reviewed the concept of reverse cholesterol transport, which describes both the metabolism and the classic anti-atherogenic function of HDL (Arterioscler. Thromb. Vasc. Biol. 20 2001 13). We here summarize the current understanding of additional biological, potentially anti-atherogenic properties of HDL. HDL inhibits the chemotaxis of monocytes, the adhesion of leukocytes to the endothelium, endothelial dysfunction and apoptosis, LDL oxidation, complement activation, platelet activation and factor X activation but also stimulates the proliferation of endothelial cells and smooth muscle cells, the synthesis of prostacyclin and natriuretic peptide C in endothelial cells, and the activation of proteins C and S. These anti-inflammatory, anti-oxidative, anti-aggregatory, anti-coagulant, and pro-fibrinolytic activities are exerted by different components of HDL, namley apolipoproteins, enzymes, and even specific phospholipids. This complexity further emphasizes that changes in the functionality of HDL rather than changes of plasma HDL-cholesterol levels determine the anti-atherogenicity of therapeutic alterations of HDL metabolism.
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Affiliation(s)
- Jerzy-Roch Nofer
- Institut für Klinische Chemie und Laboratoriumsmedizin, Westfälische Wilhelms-Universität, Albert Schweitzer Str. 33, 48129 Münster, Germany.
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29
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Brouillette CG, Anantharamaiah GM, Engler JA, Borhani DW. Structural models of human apolipoprotein A-I: a critical analysis and review. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1531:4-46. [PMID: 11278170 DOI: 10.1016/s1388-1981(01)00081-6] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human apolipoprotein (apo) A-I has been the subject of intense investigation because of its well-documented anti-atherogenic properties. About 70% of the protein found in high density lipoprotein complexes is apo A-I, a molecule that contains a series of highly homologous amphipathic alpha-helices. A number of significant experimental observations have allowed increasing sophisticated structural models for both the lipid-bound and the lipid-free forms of the apo A-I molecule to be tested critically. It seems clear, for example, that interactions between amphipathic domains in apo A-I may be crucial to understanding the dynamic nature of the molecule and the pathways by which the lipid-free molecule binds to lipid, both in a discoidal and a spherical particle. The state of the art of these structural studies is discussed and placed in context with current models and concepts of the physiological role of apo A-I and high-density lipoprotein in atherosclerosis and lipid metabolism.
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Affiliation(s)
- C G Brouillette
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, AL 35294-0005, USA.
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30
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Cockerill GW, Reed S. High-density lipoprotein: multipotent effects on cells of the vasculature. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 188:257-97. [PMID: 10208014 DOI: 10.1016/s0074-7696(08)61569-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The epidemiological evidence showing a strong inverse correlation between the level of plasma high-density lipoprotein (HDL) and the incidence of heart disease suggests that HDL has a protective effect against cardiovascular disease. The mechanism of this protective effect has been the raison d'etre for much research. The ability of HDL to mediate cholesterol efflux from peripheral tissues has been used to explain the cardioprotective effect of HDL. However, there is little direct evidence to suggest that in subjects with low plasma levels of HDL the rate of cholesterol efflux from peripheral tissues is significantly reduced. This observation suggested that HDL may be mediating its protective effect through other mechanisms. This review provides an account of the burgeoning evidence that HDL has many effects on cellular processes, in addition to the effects on cholesterol efflux, and will illustrate the multipotency of this lipoprotein.
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Affiliation(s)
- G W Cockerill
- Department of Cardiovascular Medicine, National Heart and Lung Institute, Imperial College School of Medicine, London, United Kingdom
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31
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Furlaneto C, Campa A. The effect in vitro of high-density lipoprotein from healthy and infected humans on the oxidative metabolism of polymorphonuclear leukocytes. Cell Biochem Funct 1997; 15:39-45. [PMID: 9075336 DOI: 10.1002/(sici)1099-0844(199703)15:1<39::aid-cbf718>3.0.co;2-d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We studied the effects in vitro of high-density lipoprotein from healthy (N-HDL) and from infected humans (AP-HDL) on the oxidative metabolism of human polymorphonuclear leukocytes (PMN). Products of the H2O2-MPO-halide system were monitored by luminol-enhanced chemiluminescence and superoxide anion formation was monitored by lucigenin-enhanced chemiluminescence during stimulation of human PMN with phorbol myristate acetate (PMA) or an opsonized stimulus (OS). The results showed that N-HDL and AP-HDL affect the oxidative metabolism of PMN in different ways. The possible role of this effect is discussed.
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Affiliation(s)
- C Furlaneto
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brasil
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32
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Epand RM, Shai Y, Segrest JP, Anantharamaiah GM. Mechanisms for the modulation of membrane bilayer properties by amphipathic helical peptides. Biopolymers 1995; 37:319-38. [PMID: 7632881 DOI: 10.1002/bip.360370504] [Citation(s) in RCA: 175] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The amphipathic helix, in which hydrophobic and hydrophilic residues are grouped on opposing faces, is a structural motif found in many peptides and proteins that bind to membranes. One of the physical properties of membranes that can be altered by the binding of amphipathic helices is membrane monolayer curvature strain. Class A amphipathic helices, which are present in exchangeable plasma lipoproteins, can stabilize membranes by reducing negative monolayer curvature strain; proline-punctuated class A amphipathic helical segments are particularly effective in this regard. This property is suggested to be associated with some of the beneficial biological effects of this protein. On the other hand, lytic amphipathic helical peptides can act by increasing negative curvature strain or by forming pores composed of helical clusters. Thus, different amphipathic helical peptides can be membrane stabilizing or be lytic to membranes, depending on the structural motif of the helix, which in turn determines the nature of its association with membranes. Features of these peptides that are responsible for their specific properties are discussed.
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Affiliation(s)
- R M Epand
- Department of Biochemistry, McMaster University, Hamilton, ON, Canada
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33
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Väkevä A, Jauhiainen M, Ehnholm C, Lehto T, Meri S. High-density lipoproteins can act as carriers of glycophosphoinositol lipid-anchored CD59 in human plasma. Immunology 1994; 82:28-33. [PMID: 7519171 PMCID: PMC1414855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
CD59 (protectin) is a glycophosphoinositol (GPI) lipid-anchored inhibitor of complement lysis that is expressed on the membranes of blood cells, endothelial cells, epithelial cells and cardiomyocytes. CD59 may be shed from cell surfaces, e.g. during cell injury, but when entering human plasma its fate is unknown. In this study we observed that radiolabelled lipid-anchored CD59, but not soluble urinary CD59 without anchor lipid, incorporated into high-density lipoprotein (HDL) particles when mixed with human serum and analysed by high resolution gel filtration and anti-apoA-I affinity chromatography. Only a small proportion of CD59 entered the low-density lipoprotein (LDL) fraction. HDL particles were capable of incorporating 25-42% of [125I]CD that was preinserted into the membranes of rabbit erythrocytes (RaE) and transferred 7-14% of [125I]CD59 back to RaE or to cultured human endothelial cells (EA.hy 926). Immunoaffinity purification and immunoblotting analysis demonstrated that HDL isolated from normolipidemic human serum contained small amounts of CD59. These results suggest that HDL particles could be involved in the recycling of GPI lipid-anchored molecules released from cell surfaces.
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Affiliation(s)
- A Väkevä
- Department of Bacteriology and Immunology, University of Helsinki, Finland
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34
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35
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Tytler E, Segrest J, Epand R, Nie S, Epand R, Mishra V, Venkatachalapathi Y, Anantharamaiah G. Reciprocal effects of apolipoprotein and lytic peptide analogs on membranes. Cross-sectional molecular shapes of amphipathic alpha helixes control membrane stability. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80655-3] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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36
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Choi-Miura NH, Sakamoto T, Ohtaki S, Nakamura H, Ishizawa S, Takagi Y, Gomi K, Tomita M. Elevated complement activities of sera from patients with high density lipoprotein deficiency (Tangier disease): the presence of normal level of clusterin and the possible implication in the atherosclerosis. Clin Exp Immunol 1993; 93:242-7. [PMID: 8348751 PMCID: PMC1554838 DOI: 10.1111/j.1365-2249.1993.tb07973.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Clusterin (apolipoprotein J, SP-40,40), as well as apolipoprotein A-I (apo A-I) and apolipoprotein A-II (apo A-II), are apolipoprotein components of high density lipoprotein (HDL), but not of low density lipoprotein. In spite of the deficiencies of apo A-I, apo A-II and HDL in the sera of patients with Tangier disease, clusterin was found in them at normal level. While clusterin was present as the component of HDL with apo A-I in sera of normal donors, it was present as a protein which did not form a complex in sera of Tangier patients. SC5b-9 made from the sera of Tangier patients contained normal amounts of clusterin and was deficient in apo A-I, indicating that clusterin could be incorporated into the SC5b-9 complex without apo A-I. The complement activities of the sera of the patients were higher than those of normal donors. These results may be explained by the deficiencies of apo A-I, apo A-II and HDL in the patients, because they were suggested to be the inhibitors of the reactive haemolysis of complement. The elevated complement activities of the patients might be related to the severe atherosclerotic lesions in Tangier disease.
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Affiliation(s)
- N H Choi-Miura
- Department of Physiological Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan
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37
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Interaction between apolipoproteins A-I and A-II and the membrane attack complex of complement. Affinity of the apoproteins for polymeric C9. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53740-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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38
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Peck-Miller KA, Darveau RP, Fell HP. Identification of serum components that inhibit the tumoricidal activity of amphiphilic alpha helical peptides. Cancer Chemother Pharmacol 1993; 32:109-15. [PMID: 8485805 DOI: 10.1007/bf00685612] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Antimicrobial peptides that can form amphiphilic alpha helices were tested for their ability to lyse various human tumor cell lines in vitro. These peptides include C18G, whose sequence is a derivative of the carboxyl terminus of human platelet factor IV, and 399, an idealized amphiphilic alpha helix. Both peptides exhibited potent antitumor activity against all cell lines tested, unlike magainin 2, a naturally occurring antimicrobial peptide of similar structure, which was relatively inactive under the same conditions. Also, the lytic activity of C18G is specific for tumor cells versus human red blood cells. The effects of serum can be important when evaluating the potency of lytic peptides, since other tumoricidal peptides have been shown to be completely inactivated by low serum levels. Experiments with C18G and 399 revealed that their activity was indeed reduced in the presence of human serum, but that significant lytic activity remained even at relatively high serum concentrations. Various serum components were tested for their inhibitory activity. Whereas albumin and high-density lipoprotein had only slight inhibitory properties, low-density lipoprotein was found to be a potent inhibitor of peptide-mediated cell lysis. The peptide 399, which is more sensitive to serum inhibition than C18G, also binds more extensively to all serum components tested.
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Affiliation(s)
- K A Peck-Miller
- Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, WA 98121
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39
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Hamilton KK, Sims PJ. The terminal complement proteins C5b-9 augment binding of high density lipoprotein and its apolipoproteins A-I and A-II to human endothelial cells. J Clin Invest 1991; 88:1833-40. [PMID: 1752944 PMCID: PMC295750 DOI: 10.1172/jci115504] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Terminal complement protein complexes C5b-9 have been found in human atherosclerotic lesions. Insertion of C5b-9 in the endothelial cell membrane alters permeability, induces membrane vesiculation, and activates secretion. We hypothesized that complement might also alter interactions of the endothelial surface with lipoproteins, particularly high density lipoprotein (HDL), which is reported to inhibit C5b-9-induced hemolysis. We now demonstrate that exposure to C5b-9 increases (by 2- to 50-fold) specific binding of HDL and its apolipoproteins (apo) A-I and A-II to endothelial cells. Binding to cells exposed to antibody, C5b67, and C5b-8 was virtually unchanged. Enhanced binding was also dependent on the number of C5b-9 complexes deposited on the cells. Other agonists that activate endothelial secretion did not augment binding. Calcium was required for full exposure of new binding sites by C5b-9. The C5b-9-induced increase in binding was independent of the increase observed after cholesterol loading. In addition, apo A-I and A-II appear to compete for the same binding sites on untreated and C5b-9-treated cells. In contrast to the data reported for red cells, we were unable to detect significant inhibition of C5b-9-mediated endothelial membrane permeabilization by HDL (up to 1 mg/ml) or by apo A-I (up to 100 micrograms/ml). These data demonstrate that the C5b-9 proteins enhance endothelial binding of HDL and its apoproteins, suggesting that intravascular complement activation may alter cholesterol homeostasis in the vessel wall.
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Affiliation(s)
- K K Hamilton
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City 73190
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40
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Matsuda K, Ishiura S, Koizumi H, Kawasaki H, Arahata K, Sugita H. Apolipoprotein B is a major perforin inhibitor protein in human serum. Mol Immunol 1991; 28:1211-6. [PMID: 1961197 DOI: 10.1016/0161-5890(91)90007-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We purified the high-molecular-weight perforin inhibitor protein from normal human serum using DEAE-cellulose, HPLC-gel filtration and hydroxylapatite chromatography. This protein was shown to be identical to the serum apolipoprotein B-100 in terms of amino acid composition and the sequence of the digested peptides. This inhibitor protein not only inhibits the membrane binding activity of perforin but also the pore insertion activity of membrane-bound perforin.
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Affiliation(s)
- K Matsuda
- National Institute of Neuroscience, NCNP, Tokyo, Japan
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41
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James RW, Hochstrasser AC, Borghini I, Martin B, Pometta D, Hochstrasser D. Characterization of a human high density lipoprotein-associated protein, NA1/NA2. Identity with SP-40,40, an inhibitor of complement-mediated cytolysis. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1991; 11:645-52. [PMID: 1903064 DOI: 10.1161/01.atv.11.3.645] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two peptides, NA1 and NA2, which we previously suggested to be associated with high density lipoproteins (HDLs), have been purified. Polyclonal antibodies against each peptide and a monoclonal antibody against NA2 have been used to further characterize them and their association with HDL. Immunoblotting studies revealed that the peptides form a complex of molecular mass of approximately 80 kd. Agarose gel filtration showed coelution of NA1/NA2 and apolipoprotein (apo) A-I, the structural protein of HDL. This was confirmed by fast protein liquid chromatography, which further indicated that up to 60% of NA1/NA2 was located within the lower density range of the HDL spectrum. Complementary studies with anti-apo A-I immunoaffinity columns provided evidence that at least 40% of NA1/NA2 was associated with HDL, an association easily disrupted by ultracentrifugal manipulation. Finally, partial amino acid sequences showed virtually complete homology with a recently identified protein, SP-40,40, or cytolysis inhibitor. The protein is suggested to have a powerful inhibitory effect on complement-mediated cell lysis. Our results could thus furnish an explanation for the previously observed modulating influence of HDL on complement activity.
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Affiliation(s)
- R W James
- Department of Medicine, University Hospital, Geneva, Switzerland
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42
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Jenne DE, Tschopp J. Molecular structure and functional characterization of a human complement cytolysis inhibitor found in blood and seminal plasma: identity to sulfated glycoprotein 2, a constituent of rat testis fluid. Proc Natl Acad Sci U S A 1989; 86:7123-7. [PMID: 2780565 PMCID: PMC298007 DOI: 10.1073/pnas.86.18.7123] [Citation(s) in RCA: 254] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A component of soluble terminal complement complexes was identified and affinity-purified to homogeneity by using a monoclonal antibody previously developed against the soluble C5b-9 complex. The protein, which we have designated complement cytolysis inhibitor (CLI), has a molecular mass of 70 kDa and consists of two nonidentical, disulfide-linked subunits of 35 kDa. Partial amino acid sequences determined for the amino-termini of the two subunits were identical with those of a recently characterized serum protein called SP-40,40. An almost full-length cDNA clone of 1651 base pairs was isolated from a human liver cDNA library by using long synthetic oligonucleotides as probes. The encoded amino acid sequence of CLI consists of 427 amino acid residues preceded by a 21-residue-long typical signal peptide and shows an overall 75.6% amino acid sequence homology to sulfated glycoprotein 2 (SGP-2), a major Sertoli cell-derived protein of rat testis fluid. As in SGP-2, proteolytic processing between residues 206 and 207 yields the two disulfide-linked subunits of plasma CLI. CLI and SGP-2 were shown to be orthologous single-copy genes in humans and rats by Southern blotting experiments. In addition, CLI was immunologically identified in human seminal plasma. Functional studies with purified terminal complement components showed that CLI suppresses the cytolytic potential of nascent C5b-7 complexes at physiological blood plasma concentrations (approximately 50 micrograms/ml). Its presence on the surface of mature sperm cells and its relative abundance in seminal plasma (approximately 250 micrograms/ml) suggest that CLI protects sperm cells and epithelial tissues against complement attack in the male reproductive tract.
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Affiliation(s)
- D E Jenne
- Institut de Biochimie, Université de Lausanne, Switzerland
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Tschopp J, Masson D. Inhibition of the lytic activity of perforin (cytolysin) and of late complement components by proteoglycans. Mol Immunol 1987; 24:907-13. [PMID: 3498887 DOI: 10.1016/0161-5890(87)90002-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The complement components (C6, C7, C8 and C9) implicated in the lysis of target cells and the pore-forming, lytic protein from cytotoxic T-lymphocytes and NK-cells, perforin, contain an amino acid sequence which is highly homologous to a repeat unit identified in the LDL-receptor (Tschopp et al., 1986, Nature, 322, 831-834). The domain of the LDL-receptor, which is thought to interact with a positively charged segment of its ligands apoprotein B and E, is rich in cysteine residues and contains a cluster of negative charges. We show that the negatively charged molecules suramin and glycosaminoglycans, the positively charged peptides protamine and polylysine, all of which are known to abolish binding of LDL to its receptor (Goldstein et al., 1985, A. Rev. cell. Biol., 1, 1-39) inhibit the lytic activities of C6, C7, C8, C9 and perforin. Moreover, these negatively charged molecules are potent inhibitors of cytolytic T-lymphocyte-mediated lysis of target cells, suggesting a functionally crucial role for perforin in cell-mediated cytolysis. We propose that the negatively charged, cysteine-rich domain of these complement proteins and perforin interacts with an as yet unidentified positively charged segment of its ligand in a manner analogous to the LDL-LDL receptor interaction. Homologous cysteine-rich domains in functionally unrelated proteins may therefore be functionally conserved as ideal rigid interaction domains with the conserved cysteine residues as framework. Specificity of the domain for its ligand would be conferred by the non-conserved amino acid residues.
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Affiliation(s)
- J Tschopp
- Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland
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Yue CC, Reynolds CW, Henkart PA. Inhibition of cytolysin activity in large granular lymphocyte granules by lipids: evidence for a membrane insertion mechanism of lysis. Mol Immunol 1987; 24:647-53. [PMID: 3657801 DOI: 10.1016/0161-5890(87)90046-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The ability of various compounds to inhibit the lytic activity of purified cytoplasmic granules from LGL tumors was tested. The lytic activity of granule cytolysin was modestly inhibited by inorganic phosphate, and various monophosphoesters, with I50 values in the range of 8-20 mM. Among monophosphoesters, choline phosphate was exceptionally potent, with an I50 of 1.4 mM. In contrast to the inhibition by phosphate esters, the parent compounds such as neutral sugars, glycerol, and choline, showed no detectable inhibition at 50 mM. A lysolipid bearing a short aliphatic chain and some detergents were inhibitory with I50 values in the range of 1 mM. Lysolipids with longer aliphatic chains, phospholipids as liposomes, and related lipid compounds were found to display potent inhibition of the hemolytic activity of LGL granule cytolysin, with I50 values in the range of 0.2-30 microM. Soluble globular proteins inhibited LGL granule cytolysin hemolytic activity with I50 of 0.07-0.4 mg/ml. However, lipoproteins were 2-3 orders of magnitude more potent inhibitors, with L50 values of less than 1 microgram/ml. The observed potent inhibition by lipid compounds lends support to a model of the lytic action of granule cytolysin in which soluble cytolysin molecules insert into the membrane lipid bilayer during the course of the lytic event.
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Affiliation(s)
- C C Yue
- Immunology Branch, National Cancer Institute, Bethesda, MD 20892
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Stanley KK, Page M, Campbell AK, Luzio JP. A mechanism for the insertion of complement component C9 into target membranes. Mol Immunol 1986; 23:451-8. [PMID: 2427933 DOI: 10.1016/0161-5890(86)90108-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Complement component C9 is a globular serum protein which can insert and polymerise in a target membrane to form a large membrane channel. The ability to insert in the membrane is conferred by amphipathetic elements of secondary structure in the central part of the molecule. Towards each end high cysteine domains are found, one of which is homologous to the apoprotein binding domains of the LDL receptor. From the sequence and topological data for C9 we present a model for its structure and insertion into the membrane.
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Masson D, Corthésy P, Nabholz M, Tschopp J. Appearance of cytolytic granules upon induction of cytolytic activity in CTL-hybrids. EMBO J 1985. [PMID: 2414099 PMCID: PMC554540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Examining a CTL-line (B6.1) with specific cytolytic activity, we have confirmed the ability of CTL-lines to produce poly C9-like, tubular complexes of two sizes (polyperforin 1 and 2). Isolated cytoplasmic granules from this cell line can induce hemolysis and contain the lysosomal marker arylsulfatase. Electron microscopial studies show that granules contain precursor molecules which are assembled into polyperforin upon addition of Ca2+. Antibodies raised against granules predominantly react with a 27-kd protein. We compared the B6.1 cell with a hybrid, PC60, derived from a cross between B6.1 and a non-cytolytic rat-thymoma. This hybrid line exhibits inducible CTL-activity. In PC60 with induced cytolytic activity, polyperforins 1 and 2, cytolytic granules and granule-associated proteins are detected. Non-cytolytic PC60 cells lack cytolytic granules and polyperforin 1, but contain polyperforin 2. These results suggest that cytolytic granules appear in parallel with the expression of cytotoxicity during T-lymphocyte differentiation.
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Stanley KK, Kocher HP, Luzio JP, Jackson P, Tschopp J. The sequence and topology of human complement component C9. EMBO J 1985; 4:375-82. [PMID: 4018030 PMCID: PMC554196 DOI: 10.1002/j.1460-2075.1985.tb03639.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A partial nucleotide sequence of human complement component C9 cDNA representing 94% of the coding region of the mature protein is presented. The amino acid sequence predicted from the open reading frame of this cDNA concurs with the amino acid sequence at the amino-terminal end of three proteolytic fragments of purified C9 protein. No long stretches of hydrophobic residues are present, even in the carboxy-terminal half of the molecule which reacts with lipid-soluble photoaffinity probes. Monoclonal antibody epitopes have been mapped by comparing overlapping fragments of C9 molecule to which the antibodies bind on Western blots. Several of these epitopes map to small regions containing other surface features (e.g., proteolytic cleavage sites and N-linked oligosaccharide). The amino-terminal half of C9 is rich in cysteine residues and contains a region with a high level of homology to the LDL receptor cysteine-rich domains. A model for C9 topology based on these findings is proposed.
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Packman CH, Rosenfeld SI, Leddy JP. High-density lipoprotein and its apolipoproteins inhibit cytolytic activity of complement. Studies on the nature of inhibitory moiety. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 812:107-15. [PMID: 3917679 DOI: 10.1016/0005-2736(85)90527-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Human high-density lipoprotein (HDL) and its apolipoproteins A-I and A-II inhibit complement-mediated lysis of human and sheep erythrocytes. This inhibitory activity under study is exerted after C9 is bound to membrane-associated C5b-8 complexes but prior to completed assembly and insertion of the C5b-9 complex. In this paper, we define some structure-activity relationships of the inhibitory moiety. With the exception of weak lytic inhibitory activity found in LDL/VLDL pools and in some unconcentrated minor fractions of plasma obtained by hydrophobic chromatography, all inhibitor activity was found in fractions which contained either apolipoprotein A-I, apolipoprotein A-II, or both. Intact HDL has a high level of inhibitor activity but delipidation by chloroform-methanol extraction was associated with an increase in activity on a protein-weight basis. Purified apolipoprotein A-I and apolipoprotein A-II exhibited equal inhibitory activity, greater than that exhibited by intact HDL. Nevertheless, ultracentrifugal fractions in which no free apolipoproteins could be demonstrated still possessed inhibitory activity. These experiments suggest that delipidation of HDL is not necessary for expression of inhibitor activity, although we could not rule out the possibility that apolipoproteins in dynamic equilibrium with HDL are responsible for the inhibitor activity observed in whole serum and plasma and in HDL preparations. Limited proteinase digestion completely abolished the inhibitory activity of partially delipidated HDL. Phospholipase C had little or no effect on the inhibitory activity of delipidated HDL, apolipoprotein A-I or apolipoprotein A-II, but reduced the inhibitory activity of intact HDL. These data suggest that the phospholipid polar headgroups are not necessary for inhibitory activity. However, the loss of these headgroups is associated with decreased activity, possibly due to increased hydrophobicity of HDL, or increased association among HDL micelles, and subsequent decrease in effective molar concentration of the inhibitory moiety.
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