1
|
Zhou JC, Zhu Y, Gong C, Liang X, Zhou X, Xu Y, Lyu D, Mo J, Xu J, Song J, Che X, Sun S, Huang C, Liu XL. The GC2 haplotype of the vitamin D binding protein is a risk factor for a low plasma 25-hydroxyvitamin D concentration in a Han Chinese population. Nutr Metab (Lond) 2019; 16:5. [PMID: 30651747 PMCID: PMC6332541 DOI: 10.1186/s12986-019-0332-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/02/2019] [Indexed: 02/08/2023] Open
Abstract
Background The GC haplotype of the vitamin D binding protein (encoded by the GC gene) might be a risk factor to the vitamin D (VD) nutritional status for many populations, while evidences from the Chinese Han population are sparse. We test the association between vitamin D binding protein genotypes and VD status as well as the metabolic parameters of glucose and lipids in a Han Chinese population. Methods In a cross-sectional study conducted at a health examination centre (registered in ClinicalTrials.gov as QLS2013), 2641 adults were included and grouped according to their plasma 25-hydroxyvitamin D (25OHD) concentrations as VD deficient (VDD), insufficient (VDI), or sufficient (VDS). The rs7041 and rs4588 genotypes were analysed with a molecular beacon-based qPCR method using blood samples. Results Plasma 25OHD concentrations were lower in the GC2/2, rs7041T/T, and rs4588A/A genotypes than the GC1f/1s, rs7041G/T, and rs4588C/C genotypes (P < 0.05). After adjusting for confounders, the GC2 haplotype increased the risk of low VD status (P < 0.05) in both genders. More genotypic models revealed the negative contributions of rs4588A than rs7041T to low VD status (P < 0.05). The combined rates of VDD and VDI were 80.2% in males and 86.1% in females. Compared with VDI, VDS, or both, VDD showed higher plasma concentrations of fasting blood glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides in males (P < 0.05); however, no significant differences were found with regard to these parameters between the subgroups defined by the GC genotypes (P > 0.05). Conclusions In a Han Chinese population, the GC2 haplotype or more exactly rs4588A is a risk factor for low VD status but is not associated with glucose and lipid metabolic disorders, which are inversely correlated with the circulating 25OHD concentration in males. Trial registration The study was retrospectively registered in January 2018 as NCT03406234 in the ClinicalTrials.gov online system. Electronic supplementary material The online version of this article (10.1186/s12986-019-0332-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ji-Chang Zhou
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China.,2School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, 518100 Guangdong China
| | - Yumei Zhu
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Chunmei Gong
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Xiongshun Liang
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Xiaoying Zhou
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Yuanfei Xu
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Deliang Lyu
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Junluan Mo
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Jian Xu
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Jinping Song
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Xiaoling Che
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| | - Shiqiang Sun
- Shenzhen Qilinshan Sanatorium, Shenzhen, 518055 Guangdong China
| | - Changhua Huang
- Shenzhen Qilinshan Sanatorium, Shenzhen, 518055 Guangdong China
| | - Xiao-Li Liu
- Shenzhen Centre for Chronic Disease Control, 2021 Buxin Road, Luohu District, Shenzhen, 518020 Guangdong China
| |
Collapse
|
2
|
Jorde R, Schirmer H, Wilsgaard T, Joakimsen RM, Mathiesen EB, Njølstad I, Løchen ML, Figenschau Y, Berg JP, Svartberg J, Grimnes G. Polymorphisms related to the serum 25-hydroxyvitamin D level and risk of myocardial infarction, diabetes, cancer and mortality. The Tromsø Study. PLoS One 2012; 7:e37295. [PMID: 22649517 PMCID: PMC3359337 DOI: 10.1371/journal.pone.0037295] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 04/17/2012] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Low serum 25(OH)D levels are associated with cardiovascular risk factors, and also predict future myocardial infarction (MI), type 2 diabetes (T2DM), cancer and all-cause mortality. Recently several single nucleotide polymorphisms (SNPs) associated with serum 25-hydroxyvitamin D (25(OH)D) level have been identified. If these relations are causal one would expect a similar association between these SNPs and health. METHODS DNA was prepared from subjects who participated in the fourth survey of the Tromsø Study in 1994-1995 and who were registered with the endpoints MI, T2DM, cancer or death as well as a randomly selected control group. The endpoint registers were complete up to 2007-2010. Genotyping was performed for 17 SNPs related to the serum 25(OH)D level. RESULTS A total of 9528 subjects were selected for genetic analyses which were successfully performed for at least one SNP in 9471 subjects. Among these, 2025 were registered with MI, 1092 with T2DM, 2924 with cancer and 3828 had died. The mean differences in serum 25(OH)D levels between SNP genotypes with the lowest and highest serum 25(OH)D levels varied from 0.1 to 7.8 nmol/L. A genotype score based on weighted risk alleles regarding low serum 25(OH)D levels was established. There was no consistent association between the genotype score or individuals SNPs and MI, T2DM, cancer, mortality or risk factors for disease. However, for rs6013897 genotypes (located at the 24-hydroxylase gene (CYP24A1)) there was a significant association with breast cancer (P<0.05). CONCLUSION Our results do not support nor exclude a causal relationship between serum 25(OH)D levels and MI, T2DM, cancer or mortality, and our observation on breast cancer needs confirmation. Further genetic studies are warranted, particularly in populations with vitamin D deficiency. TRIAL REGISTRATION ClinicalTrials.gov NCT01395303.
Collapse
Affiliation(s)
- Rolf Jorde
- Tromsø Endocrine Research Group, Department of Clinical Medicine, University of Tromsø, and Division of Internal Medicine, University Hospital of North Norway, Tromsø, Norway.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
McGrath JJ, Saha S, Burne THJ, Eyles DW. A systematic review of the association between common single nucleotide polymorphisms and 25-hydroxyvitamin D concentrations. J Steroid Biochem Mol Biol 2010; 121:471-7. [PMID: 20363324 DOI: 10.1016/j.jsbmb.2010.03.073] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 03/23/2010] [Accepted: 03/25/2010] [Indexed: 02/07/2023]
Abstract
In order to appreciate the association between hypovitaminosis D and various adverse health outcomes, we require a thorough understanding of how common single nucleotide polymorphisms (SNPs) influence serum concentrations of 25-hydroxyvitamin D (25OHD). We undertook a systematic review of the literature in order to identify studies that examined 25OHD concentrations, and common SNPs. We found nine studies related to the vitamin D binding protein (group-specific component, GC), and five studies examining the vitamin D receptor (VDR). SNPs in a range of cytochrome P450 enzymes have also been examined in seven studies. Replicated findings have been found between 25OHD concentrations and (a) two SNPs in GC (rs4588, rs7041), (b) one SNP in VDR (rs10735810), and (c) one SNP in CYP27B1 (rs10877012). In light of these associations, it is feasible that optimal concentrations of 25OHD required to reduce disease outcomes may vary according to genotype. We speculate that recently identified U-shaped relationships between 25OHD concentrations and disease outcomes (i.e. increased risk at both high and low concentrations) may reflect a mixture of genotype-defined subgroups. Further research is required in order to clarify the genetic architecture underlying 25OHD serum concentrations, and to unravel the mechanisms of action responsible for these associations.
Collapse
Affiliation(s)
- John J McGrath
- Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Locked Bag 500, Richlands Q4077, Australia.
| | | | | | | |
Collapse
|
4
|
Martineau AR, Leandro ACCS, Anderson ST, Newton SM, Wilkinson KA, Nicol MP, Pienaar SM, Skolimowska KH, Rocha MA, Rolla VC, Levin M, Davidson RN, Bremner SA, Griffiths CJ, Eley BS, Bonecini-Almeida MG, Wilkinson RJ. Association between Gc genotype and susceptibility to TB is dependent on vitamin D status. Eur Respir J 2010; 35:1106-12. [PMID: 19797128 PMCID: PMC2864196 DOI: 10.1183/09031936.00087009] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Group-specific component (Gc) variants of vitamin D binding protein differ in their affinity for vitamin D metabolites that modulate antimycobacterial immunity. We conducted studies to determine whether Gc genotype associates with susceptibility to tuberculosis (TB). The following subjects were recruited into case-control studies: in the UK, 123 adult TB patients and 140 controls, all of Gujarati Asian ethnic origin; in Brazil, 130 adult TB patients and 78 controls; and in South Africa, 281 children with TB and 182 controls. Gc genotypes were determined and their frequency was compared between cases versus controls. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were obtained retrospectively for 139 Gujarati Asians, and case-control analysis was stratified by vitamin D status. Interferon (IFN)-gamma release assays were also performed on 36 Gujarati Asian TB contacts. The Gc2/2 genotype was strongly associated with susceptibility to active TB in Gujarati Asians, compared with Gc1/1 genotype (OR 2.81, 95% CI 1.19-6.66; p = 0.009). This association was preserved if serum 25(OH)D was <20 nmol.L(-1) (p = 0.01) but not if serum 25(OH)D was > or =20 nmol.L(-1) (p = 0.36). Carriage of the Gc2 allele was associated with increased PPD of tuberculin-stimulated IFN-gamma release in Gujarati Asian TB contacts (p = 0.02). No association between Gc genotype and susceptibility to TB was observed in other ethnic groups studied.
Collapse
Affiliation(s)
- A R Martineau
- Wellcome Trust Centre for Research in Clinical Tropical Medicine, Division of Medicine, Imperial College London, London, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Speeckaert MM, Glorieux GL, Vanholder R, Van Biesen W, Taes YE, Clement F, Wehlou C, Delanghe JR. Vitamin D Binding Protein and the Need for Vitamin D in Hemodialysis Patients. J Ren Nutr 2008; 18:400-7. [DOI: 10.1053/j.jrn.2008.04.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Indexed: 11/11/2022] Open
|
6
|
Yasuda T, Kishi K. Duplication of 1F and 1A2 genes in the vitamin D-binding protein (GC) system. Hum Genet 1994; 93:361-2. [PMID: 8125494 DOI: 10.1007/bf00212044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
7
|
Arnaud J, Constans J. Affinity differences for vitamin D metabolites associated with the genetic isoforms of the human serum carrier protein (DBP). Hum Genet 1993; 92:183-8. [PMID: 8370586 DOI: 10.1007/bf00219689] [Citation(s) in RCA: 263] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Human vitamin D binding protein (DBP) displays considerable polymorphism with 120 described alleles. Among these, three alleles are frequently observed, Gc 1F (pI 4.94-4.84), Gc 1S (pI 4.95-4.85) and Gc 2 (pI 5.1). Differences between these genetic forms of the protein in affinity for vitamin D metabolites have been detected by electrophoretic methods. The constant affinity (Ka) values determined in this study confirm these differences. The affinities of six rare variants were also examine. Those of the DBP genetic forms to the vitamin D derivatives 25-OH-D3 and 1,25-(OH)2-D3 seem to be related to the isoelectric point of the proteins: a high affinity corresponding to a low isoelectric point. The Gc 1A9 and 1A11 mutants were associated with higher affinity for the vitamin D derivatives and the Gc 1C1 and 1C21 mutants were deficient.
Collapse
Affiliation(s)
- J Arnaud
- CRPG-CRNS, CHU Purpan, Toulouse, France
| | | |
Collapse
|
8
|
Braun A, Brandhofer A, Cleve H. Interaction of the vitamin D-binding protein (group-specific component) and its ligand 25-hydroxy-vitamin D3: binding differences of the various genetic types disclosed by isoelectric focusing. Electrophoresis 1990; 11:478-83. [PMID: 2394211 DOI: 10.1002/elps.1150110608] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The three common variants of the vitamin D binding protein, also known as group specific component (Gc), namely types 1S, 1F and 2, as well as some rare variants were studied by thin-layer polyacrylamide gel isoelectric focusing in a pH 4.5-5.4 carrier ampholyte generated pH gradient, additionally containing N-(2-acetamido)-2-aminoethanesulfonic acid (ACES). Prior to isoelectric focusing, whole serum or purified preparations of the vitamin D binding protein were incubated with 25-hydroxycholecalciferol at various ligand/protein ratios. Binding differences were found for the anodal and cathodal isoforms of Gc 1 variants and also for various allelic types. Isoforms with higher isoelectric points generally had a lower affinity for the ligand than the variants with lower isoelectric points.
Collapse
Affiliation(s)
- A Braun
- Institut für Anthropologie und Humangenetik der Universität München, Federal Republic of Germany
| | | | | |
Collapse
|
9
|
Yasuda T, Ikehara Y, Takagi S, Mizuta K, Kishi K. A hereditary double double-banded variation in the vitamin D-binding protein (GC) system analyzed by immunoblotting: duplication of the 1F and 1A2 genes? Hum Genet 1989; 82:89-91. [PMID: 2714784 DOI: 10.1007/bf00288282] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A combination of immunoblotting and polyacrylamide gel isoelectric focusing (IEF-PAGE) was used to define a new genetic variant in the (GC) group-specific component system. This appeared to be a GC 1-type variant, and was presumed to have arisen from duplication of the GC 1F and GC 1A2 genes.
Collapse
Affiliation(s)
- T Yasuda
- Department of Legal Medicine, Fukui Medical School, Japan
| | | | | | | | | |
Collapse
|
10
|
Boutin B, Galbraith RM, Arnaud P. Comparative affinity of the major genetic variants of human group-specific component (vitamin D-binding protein) for 25-(OH) vitamin D. JOURNAL OF STEROID BIOCHEMISTRY 1989; 32:59-63. [PMID: 2913402 DOI: 10.1016/0022-4731(89)90014-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Binding studies with [3H] 25-(OH) D3 were performed under a variety of conditions using Gc (Vitamin D-binding protein) purified from individuals displaying different phenotypes. No significant differences in affinity of binding were found between Gc1f, Gc1s and Gc2 allelle products in either homozygous or heterozygous individuals, nor between Gc1 anodal and Gc1 cathodal isotypes. Affinity was not significantly affected by different reaction temperatures (4, 22 or 37 degrees C), the presence or absence of Ca2+ ions, and binary and ternary interactions with G-actin and G-actin-DNase complexes respectively. However, reduction of pH caused a progressive decrease in binding with virtual abolition at pH less than or equal to 5.0. The latter might promote dissociation of D3 metabolites from Gc carrier protein in acidic compartments of cells.
Collapse
Affiliation(s)
- B Boutin
- Department of Microbiology, Medical University of South Carolina, Charleston 29425
| | | | | |
Collapse
|
11
|
Saha N. Distribution of group-specific component (Gc) subtypes in several Mongoloid populations of East Asia. Ann Hum Biol 1989; 16:53-60. [PMID: 2919862 DOI: 10.1080/03014468900000162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The distribution of group-specific component (Gc) subtypes was determined by isoelectric focussing in thin layer polyacrylamide gels of pH range 4 to 6.5, in a group of 2412 individuals from 10 Mongoloid populations of East Asia. The sample comprised 959 Chinese from different localities (Singapore, 249; Malaysia, 347; Taiwan, 246; Hong Kong, 57; Fuzhou mainland, 60), 338 Koreans, 277 Filipinos, 484 Thais, 330 Malays and 24 Indonesians. The Filipinos and Malays had lower frequencies of Gc2 (0.15 and 0.18) compared to other Mongoloid populations (0.23 to 0.32) and the Chinese (0.24 to 0.32). The frequencies of Gc1F varied from 0.39 to 0.49 in the Chinese and 0.35 to 0.52 in other Mongoloid populations. Low frequency of rarer variants was observed in most of the populations. The average frequency of Gc2 was higher in the Japanese (0.26 +/- 0.01) than in the Chinese (0.24 +/- 0.02), and in Mongoloids of East Asia (0.23 +/- 0.01) and South-East Asia (0.17 +/- 0.01). The average frequencies of Gc1F and Gc1S were similar in the Chinese and Japanese, whereas the Mongoloids of South-East Asia had a much higher frequency of Gc1F and a lower frequency of Gc1S than the Chinese, Japanese and East Asian Mongoloid populations.
Collapse
Affiliation(s)
- N Saha
- Department of Biochemistry, Faculty of Medicine, National University of Singapore
| |
Collapse
|
12
|
Kamboh MI, Ferrell RE. Ethnic variation in vitamin D-binding protein (GC): a review of isoelectric focusing studies in human populations. Hum Genet 1986; 72:281-93. [PMID: 3516862 DOI: 10.1007/bf00290950] [Citation(s) in RCA: 130] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Since the discovery in 1977 that the GC1 gene could be resolved into two common subcomponents on an isoelectric focusing (IEF) gel, a large number of ethnic groups have been screened to analyze the extent of genetic variation in human populations. Using the IEF technique, approximately 50,000 individuals from 160 different populations have been tested for the GC polymorphism. A marked variation in common GC suballele frequencies in different geographic areas seems to correlate with skin pigmentation and intensity of sun light. Pigmented (black) and keratinized (yellowish) skin type populations have a relatively high frequency of the GC*IF allele as compared to white skin populations. By comparison non-pigmented and non-keratinized white skin populations are generally characterized by having the maximum values of the GC*IS allele. The anthropologic significance of the GC locus has been enhanced further by detecting additional unique GC variants which provide useful information about evolutionary links between different populations. However, the presence of some electrophoretically identical unique variants in genetically and geographically distinct populations demand further investigation of these allelic variants to shed more light on their origins.
Collapse
|
13
|
Constans J, Hazout S, Garruto RM, Gajdusek DC, Spees EK. Population distribution of the human vitamin D binding protein: anthropological considerations. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 1985; 68:107-22. [PMID: 4061596 DOI: 10.1002/ajpa.1330680110] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The polymorphism of the serum vitamin D binding protein (DBP) in humans is based on the existence of three common alleles, Gc1F, Gc1S, and Gc2, and 84 rare alleles. The geographical distribution of Gc1F, Gc1S, and Gc2 alleles shows north to south clines, together with a balanced equilibrium between the Gc1F or Gc1S allele frequency and the Gc2 frequency. The distribution of the FST values shows high variability within a geographical area. For European and North Asiatic groups, the FST values are the lowest observed, and the reason may be a long process of homogenization. Aboriginal populations from Australia and New Guinea and groups from both North Africa and South America show the greatest heterogeneity of their allele frequencies. Systematic factors such as genetic drift and selection may account for this distribution. In contrast with the three main DBP alleles, the distribution of the rare alleles corresponds to patterns of human migrations that occurred during prehistoric and historic periods. Thus, the rare mutants are of particular relevance to anthropological and genetical investigations.
Collapse
|
14
|
Abstract
In the course of a paternity investigation an apparent mother-child incompatibility was observed in the Gc system. An extensive family study was undertaken to test the hypothesis of a silent gene or null allele responsible for the contrary phenotypes: the mother had the type Gc 2, the son was GC 1. The apparent incompatibility was due to a "pseudo" silent allele, called Gc * 1, which controlled a group-specific component with extremely reduced serum concentrations. This double-band mutant could be differentiated from the Gc 1S bands by two-dimensional electrophoresis: isoelectric focusing (IEF)/6 M urea IEF. The allele Gc * 1 was found in 12 persons from this family, it was not associated with any apparent disease state. Also present in this family was the variant Gc 1C1. Pedigree analysis revealed a possible (not significant) distorted segregation ratio for the allele Gc * 1C1, which was found in 22 of 33 offspring from marriages with one parent heterozygous for Gc * 1C1.
Collapse
|
15
|
Viau M, Constans J, Debray H, Montreuil J. Isolation and characterization of the O-glycan chain of the human vitamin-D binding protein. Biochem Biophys Res Commun 1983; 117:324-31. [PMID: 6689265 DOI: 10.1016/0006-291x(83)91579-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
On a highly purified preparation, the structure of the carbohydrate chain of the human vitamin D-binding protein was investigated and two genetic forms of this protein were considered (Gc 2 and Gc 1 proteins). It was found that only the Gc 1 protein (Gc1a isoform) was glycosylated, the glycan moiety representing about 1% of the protein. The structure of this O-glycosidically linked glycan was determined to be: Neu Ac alpha (2 leads to 3) Gal beta (1 leads to 3) GaINAc alpha (1 leads to 0) Ser (or Thr). A tetrasaccharidic O-glycan with two N-acetylneuraminic residues was also characterized. The vitamin D-binding protein is a rare example of a serum protein O-glycosylated only on some genetic forms.
Collapse
|
16
|
Constans J, Arlet P, Viau M, Bouissou C. Unusual sialilation of the serum DBP associated with the Gc 1 allele in alcoholic cirrhosis of the liver. Clin Chim Acta 1983; 130:219-30. [PMID: 6688204 DOI: 10.1016/0009-8981(83)90119-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The serum level of the 'vitamin D binding protein' (DBP) or Gc ('group-specific component'), its phenotype distribution and the quantitative estimation of the different electrophoretic isoforms were determined in a sample of healthy individuals (blood donors) and in patients with alcoholic hepatitis. It is shown that the serum DBP levels and the amount of the different electrophoretic isoforms are influenced by the protein phenotypes. In the patients an increased frequency of the Gc 1 allele is noticed. For the first time, an unusual form of the apo DBP protein was detected but only in the sera of the Gc 1 allele carriers. The protein form investigated by analytical procedures presents one more sialic acid residue than the usual Gc 1 protein. This unusual metabolic transformation of the DBP is mostly observed among male patients and is often associated with a deteriorating clinical outcome.
Collapse
|
17
|
Marx SJ, Liberman UA, Eil C. Calciferols: actions and deficiencies in action. VITAMINS AND HORMONES 1983; 40:235-308. [PMID: 6369768 DOI: 10.1016/s0083-6729(08)60436-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
18
|
Constans J, Oksman F, Viau M. Binding of the apo and holo forms of the serum vitamin D-binding protein to human lymphocyte cytoplasm and membrane by indirect immunofluorescence. Immunol Lett 1981; 3:159-62. [PMID: 7026425 DOI: 10.1016/0165-2478(81)90120-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The indirect immunofluorescence method is used to study the binding of the serum vitamin D carrier protein (DBP) to lymphocytes. It is shown that in vitro this serum protein will bind to the lymphocyte cytoplasm and intact membrane. This result is in agreement with recent evidence of an actin-binding protein present in the serum. Besides, a difference in the binding to the lymphocyte membrane is observed between the holo forms of the DBP with the different vitamin D derivatives. These findings could be relevant in illuminating the possible role of the DBP in the cellular metabolism of the active metabolites of vitamin D and in the cellular mobility.
Collapse
|
19
|
Brenner T, Abramsky O. Immunosuppression of experimental autoimmune myasthenia gravis by alpha-fetoprotein rich formation. Immunol Lett 1981; 3:163-7. [PMID: 6169635 DOI: 10.1016/0165-2478(81)90121-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|