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Copenhaver M, Yu CY, Hoffman RP. Complement Components, C3 and C4, and the Metabolic Syndrome. Curr Diabetes Rev 2019; 15:44-48. [PMID: 29663892 DOI: 10.2174/1573399814666180417122030] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/10/2017] [Accepted: 12/13/2017] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Increased systemic inflammation plays a significant role in the development of adult cardiometabolic diseases such as insulin resistance, dyslipidemia, atherosclerosis, and hypertension. The complement system is a part of the innate immune system and plays a key role in the regulation of inflammation. Of particular importance is the activation of complement components C3 and C4. C3 is produced primarily by the liver but is also produced in adipocytes, macrophages and endothelial cells, all of which are present in adipose tissues. Dietary fat and chylomicrons stimulate C3 production. Adipocytes in addition to producing C3 also have receptors for activated C3 and other complement components and thus also respond to as well as produce a target for complement. C3adesArg, also known as acylation stimulation factor, increases adipocyte triglyceride synthesis and release. These physiological effects play a significant role in the development of metabolic syndrome. Epidemiologically, obese adults and non-obese adults with cardiometabolic disease who are not obese have been shown to have increased complement levels. C4 levels also correlate with body mass index. Genetically, specific C3 polymorphisms have been shown to predict future cardiovascular events and. D decreased C4 long gene copy number is associated with increased longevity. CONCLUSION Future research is clearly needed to clarify the role of complement in the development of cardiovascular disease and mechanisms for its action. The complement system may provide a new area for intervention in the prevention of cardiometabolic diseases.
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Affiliation(s)
- Melanie Copenhaver
- Pediatric Endocrinology Fellow, Division of Pediatric Endocrinology, Department of Pediatrics, Nationwide Children's Hospital, OH 43205, United States
| | - Chack-Yung Yu
- Pediatric Endocrinology Fellow, Division of Pediatric Endocrinology, Department of Pediatrics, Nationwide Children's Hospital, OH 43205, United States
| | - Robert P Hoffman
- Pediatric Endocrinology Fellow, Division of Pediatric Endocrinology, Department of Pediatrics, Nationwide Children's Hospital, OH 43205, United States
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Flachsbart F, Caliebe A, Heinsen FA, Hemming-Karlsen T, Schreiber S, Franke A, Nebel A. Investigation of complement component C4 copy number variation in human longevity. PLoS One 2014; 9:e86188. [PMID: 24465950 PMCID: PMC3899116 DOI: 10.1371/journal.pone.0086188] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 12/06/2013] [Indexed: 11/18/2022] Open
Abstract
Genetic factors have been estimated to account for about 25% of the variation in an adult's life span. The complement component C4 with the isotypes C4A and C4B is an effector protein of the immune system, and differences in the overall C4 copy number or gene size (long C4L; short C4S) may influence the strength of the immune response and disease susceptibilities. Previously, an association between C4B copy number and life span was reported for Hungarians and Icelanders, where the C4B*Q0 genotype, which is defined by C4B gene deficiency, showed a decrease in frequency with age. Additionally, one of the studies indicated that a low C4B copy number might be a genetic trait that is manifested only in the presence of the environmental risk factor "smoking". These observations prompted us to investigate the role of the C4 alleles in our large German longevity sample (∼ 700 cases; 94-110 years and ∼ 900 younger controls). No significant differences in the number of C4A, C4B and C4S were detected. Besides, the C4B*Q0 carrier state did not decrease with age, irrespective of smoking as an interacting variable. However, for C4L*Q0 a significantly different carrier frequency was observed in the cases compared with controls (cases: 5.08%; controls: 9.12%; p = 0.003). In a replication sample of 714 German cases (91-108 years) and 890 controls this result was not replicated (p = 0.14) although a similar trend of decreased C4L*Q0 carrier frequency in cases was visible (cases: 7.84%; controls: 10.00%).
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Affiliation(s)
- Friederike Flachsbart
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Amke Caliebe
- Institute of Medical Informatics and Statistics, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Femke-Anouska Heinsen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Tom Hemming-Karlsen
- Norwegian PSC Research Center, Division of Cancer, Surgery and Transplantation, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Research Institute for Internal Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Section of Gastroenterology, Department of Transplantation Medicine, Division of Cancer, Surgery and Transplantation, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Division of Gastroenterology, Institute of Medicine, University of Bergen, Bergen, Norway
| | - Stefan Schreiber
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
- Department of General Medicine, University Hospital Schleswig-Holstein, Kiel, Germany
- Popgen Biobank, Christian-Albrechts-University, Kiel, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Almut Nebel
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
- * E-mail:
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Bánlaki Z, Raizer G, Acs B, Majnik J, Doleschall M, Szilágyi A, Rácz K, Füst G, Patócs A. ACTH-induced cortisol release is related to the copy number of the C4B gene encoding the fourth component of complement in patients with non-functional adrenal incidentaloma. Clin Endocrinol (Oxf) 2012; 76:478-84. [PMID: 21967755 DOI: 10.1111/j.1365-2265.2011.04247.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE According to our previous findings, carriers of the C4B*Q0 genotype, which means zero or one copy of the C4B gene, which is located in the RCCX copy number variation region on chromosome 6, have a significantly shorter life-expectancy and higher risk of cardiovascular disease than non-carriers. We have postulated that the C4B*Q0 genotype is linked to variant(s) of the neighboring CYP21A2 gene encoding a steroid 21-hydroxylase with altered function. DESIGN Single-center, observational, retrospective study. PATIENTS Seventy-six patients with non-functional, benign adrenal incidentaloma. MEASUREMENTS Serum cortisol, aldosterone, 17-hydroxyprogesterone, corticosterone and ACTH levels basally and after ACTH-stimulation, metyrapone or dexamethasone tests were determined. C4B gene copy number was quantified. RESULTS The ratio of ACTH-stimulated and baseline cortisol concentrations was significantly higher (P = 0·001) in the group of patients carrying the C4B*Q0 genotype compared to the rest of the patients. This difference remained significant (P = 0·004) after adjustment for sex and age, as well as for tumor size. A significant (P = 0·018), adjusted difference between carriers and non-carriers was found also for ACTH-induced/basal aldosterone ratio. In C4B*Q0 carriers, metyrapone hardly reduced the serum cortisol level, while in non-carriers it induced a highly significant (P = 0·002) decrease. CONCLUSIONS The C4B*Q0 genotype may be associated with hyperreactivity of the HPA axis (manifested as an increased responsiveness to ACTH-stimulation), probably through enhanced function of steroid 21-hydroxylase. Since hyperreactivity of the HPA axis is known to be associated with an increased risk of cardiovascular disease, our present findings may explain the increased cardiovascular morbidity and mortality of C4B*Q0 carriers.
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Affiliation(s)
- Zsófia Bánlaki
- 3rd Department of Internal Medicine, Semmelweis University, Budapest, Hungary
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Fernando MM, Boteva L, Morris DL, Zhou B, Wu YL, Lokki ML, Yu CY, Rioux JD, Hollox EJ, Vyse TJ. Assessment of complement C4 gene copy number using the paralog ratio test. Hum Mutat 2010; 31:866-74. [PMID: 20506482 PMCID: PMC3567757 DOI: 10.1002/humu.21259] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The complement C4 locus is in the class III region of the MHC, and exhibits copy number variation. Complement C4 null alleles have shown association with a number of diseases including systemic lupus erythematosus (SLE). However, most studies to date have used protein immunophenotyping and not direct interrogation of the genome to determine C4 null allele status. Moreover, a lack of accurate C4 gene copy number (GCN) estimation and tight linkage disequilibrium across the disease-associated MHC haplotypes has confounded attempts to establish whether or not these associations are causal. We have therefore developed a high throughput paralog ratio test (PRT) in association with two restriction enzyme digest variant ratio tests (REDVRs) to determine total C4 GCN, C4A GCN, and C4B GCN. In the densely genotyped CEU cohort we show that this method is accurate and reproducible when compared to gold standard Southern blot copy number estimation with a discrepancy rate of 9%. We find a broad range of C4 GCNs in the CEU and the 1958 British Birth Cohort populations under study. In addition, SNP-C4 CNV analyses show only moderate levels of correlation and therefore do not support the use of SNP genotypes as proxies for complement C4 GCN.
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Affiliation(s)
- Michelle M.A. Fernando
- Section of Rheumatology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Lora Boteva
- Section of Rheumatology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - David L. Morris
- Section of Rheumatology, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Bi Zhou
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
| | - Yee Ling Wu
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
| | - Marja-Liisa Lokki
- Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Chack Yung Yu
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
| | - John D. Rioux
- Montréal Heart Institute, Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
| | - Edward J. Hollox
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Timothy J. Vyse
- Section of Rheumatology, Faculty of Medicine, Imperial College London, London, United Kingdom
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Mustafa A, Hamsten A, Holm G, Lefvert AK. Circulating immune complexes induced by food proteins implicated in precocious myocardial infarction. Ann Med 2001; 33:103-12. [PMID: 11327113 DOI: 10.3109/07853890109002065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Circulating immune complexes (CIC) are frequently found in postinfarction patients. The constituents of these CIC are mostly unknown. AIM The objective of the current study was to assess whether CIC containing alimentary proteins and antibodies against these proteins are implicated in precocious myocardial infarction (MI). METHODS Seventy-six survivors (67 men and 9 women, mean age 39 years) of a first MI before the age of 45 years were enrolled in this study. Two control groups were included. One group consisted of age-matched, randomly selected, population-based healthy individuals, 79 men and 11 women, without features of coronary heart disease. An additional control group was used only for the determination of serum antibodies against some of the alimentary proteins and consisted of 139 healthy blood donors, 95 men and 44 women, with a mean age of 42 years. Sucrose density gradient centrifugation, gel filtration and precipitation by polyethylene glycol were used for the isolation of CIC, and enzyme-linked immunosorbent assay (ELISA) was used to measure the immunoglobulin levels and specific antibodies against alimentary proteins in both sera and isolated CIC. Sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis and Western blotting were used to determine alimentary proteins in the CIC. RESULTS Alimentary antigens/antibodies were present in immune complex form in seven out of 14 (50%) postinfarction patients who had persistent high concentrations of CIC, the latter constituting 18% of the entire group. Antibodies of the IgG isotype predominated. A rise in CIC, signs of activation of the classical complement pathway, and a rise in plasma concentrations of von Willebrand factor antigen (vWFAg) were evident within 1 week in four patients subjected to a 2-week elimination diet followed by a single challenge with cow's milk. CONCLUSION This study suggests that dietary proteins occasionally give rise to persistent CIC, which may predispose to MI at a young age.
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Affiliation(s)
- A Mustafa
- Immunological Research Unit, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
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Kozlov LV, Lakhtin VM, Skorokhodova TG, Batalova TN, Shoibonov BB, D’yakov VL, Guzova VA, Matveevskaya NS. Isotyping of component C4 of human complement using differences in the functional activity of isotypes C4A and C4B. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2000. [DOI: 10.1007/bf02758619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The classical risk factors, hypercholesterolemia, smoking, hypertension and diabetes, explain only a part of the epidemiological features of atherosclerotic coronary heart disease. Investigations in the past few years have shown involvement of immunological mechanisms in atherosclerosis. Circulating immune complexes accelerate atherosclerosis both in experimental animal models and in humans. The fourth component of complement (C4) plays an important role in the solubilisation and elimination of immune complexes. C4 consists of two allotypes, C4A and C4B. An earlier report showed an association between C4B null alleles (C4B*Q0) and myocardial infarction and to infarction related mortality. In the present investigation, C4A*Q0 and C4B*Q0 were studied in two population samples. The first (Group I) was a cross sectional study of 100 consecutive males with myocardial infarction before the age of 45 years and 164 population based healthy controls, age and sex matched. The second (Group II) was a nested case control study in which a cohort of 50 year-old males were followed for 20 years for development of myocardial infarction between 50-60 and 60-70 years, and the results compared with those who did not develop MI. We observed no association of homozygous and/or heterozygous C4A*Q0 or C4B*Q0 with myocardial infarction occurring in the age groups < 45, 50-60 and 60-70 years or with the infarction related mortality (P > 0.05). The prevalence/frequency of C4A*Q0 and C4B*Q0 was not related to the age at which MI occurred. The prevalence of C4A*Q0 was not affected by age. We thus conclude that partial deficiency of C4 does not appear to be a major risk factor for myocardial infarction.
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Affiliation(s)
- S Nityanand
- Immunological Research Unit, Center for Molecular Medicine Karolinska Hospital, Stockholm, Sweden
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Kramer J, Fülöp T, Rajczy K, Nguyen AT, Füst G. A marked drop in the incidence of the null allele of the B gene of the fourth component of complement (C4B*Q0) in elderly subjects: C4B*Q0 as a probable negative selection factor for survival. Hum Genet 1991; 86:595-8. [PMID: 2026423 DOI: 10.1007/bf00201547] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The incidence of allotypes of the genes of the fourth component (C4) and factor B of the complement system was compared in 252 persons under 45 years of age ("young" group) with 482 people between 61 and 90 years of age ("old" group). One hundred people older than 90 years of age (nonagenarians) were also investigated. A striking difference was found between the "young" and "old" groups in the incidence (16.1% and 5.4%, respectively) of a silent gene of the C4B allele (C4B*Q0). This difference was even more marked among "young" and "old" men (17.6% vs 3.4%). The incidence of the C4B*Q0 allele in women dropped to the level of the men only in the nonagenarian group. The most probable explanation for this finding is that people carrying the C4B*Q0 allele die from as yet unidentified disease(s) in their middle-age. Therefore, male (and to a lesser extent female) carriers of this allele may have a considerably shorter life expectancy than individuals without a silent gene in the C4B locus.
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Affiliation(s)
- J Kramer
- Department of Immunopathology, National Institute of Haematology and Blood Transfusion, Budapest, Hungary
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Kramer J, Kassai T, Tauszik T, Füst G. Complement C2, C3, C4 and factor B allele distribution in the Gipsy population in Hungary. Immunol Lett 1990; 24:11-2. [PMID: 2373522 DOI: 10.1016/0165-2478(90)90029-p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Allotype frequencies of four complement proteins (C3, C2, factor B, and C4) were tested in 150 healthy Hungarian and 126 healthy Gipsy individuals living in Hungary. We observed significant differences between the two ethnic groups in the incidence of C3*F, Bf*F, C4A*Q0, C4A*3, C4B*1 and C4B*2 allotypes. Bf*F occurred more frequently among Gipsies, while frequencies for the other three allotypes was lower in this group than in Hungarians. The similarities in the allotype frequencies of C3 and Bf among Gipsy and Gaddis (India) populations supports the Indian origin of the former ethnic group.
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Affiliation(s)
- J Kramer
- National Institute of Haematology and Blood Transfusion, Budapest, Hungary
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