1
|
Zahid H, Lau AM, Kelly SM, Karu K, Gor J, Perkins SJ, McDermott LC. Identification of diverse lipid-binding modes in the groove of zinc α 2 glycoprotein reveals its functional versatility. FEBS J 2021; 289:1876-1896. [PMID: 34817923 DOI: 10.1111/febs.16293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 11/03/2021] [Accepted: 11/22/2021] [Indexed: 11/28/2022]
Abstract
ZAG is a multifunctional glycoprotein with a class I MHC-like protein fold and an α1-α2 lipid-binding groove. The intrinsic ZAG ligand is unknown. Our previous studies showed that ZAG binds the dansylated C11 fatty acid, DAUDA, differently to the boron dipyrromethane C16 fatty acid, C16 -BODIPY. Here, the molecular basis for this difference was elucidated. Multi-wavelength analytical ultracentrifugation confirmed that DAUDA and C16 -BODIPY individually bind to ZAG and compete for the same binding site. Molecular docking of lipid-binding in the structurally related Cluster of differentiation 1 proteins predicted nine conserved ligand contact residues in ZAG. Twelve mutants were accordingly created by alanine scanning site directed mutagenesis for characterisation. Mutation of Y12 caused ZAG to misfold. Mutation of K147, R157 and A158 abrogated C16 -BODIPY but not DAUDA binding. L69 and T169 increased the fluorescence emission intensity of C16 -BODIPY but not of DAUDA compared to wild-type ZAG and showed that C16 -BODIPY binds close to T169 and L69. Distance measurements of the crystal structure revealed K147 forms a salt bridge with D83. A range of bioactive bulky lipids including phospholipids and sphingolipids displaced DAUDA from the ZAG binding site but unexpectedly did not displace C16 -BODIPY. We conclude that the ZAG α1-α2 groove contains separate but overlapping sites for DAUDA and C16 -BODIPY and is involved in binding to a bulkier and wider repertoire of lipids than previously reported. This work suggested that the in vivo activity of ZAG may be dictated by its lipid ligand.
Collapse
Affiliation(s)
- Henna Zahid
- Department of Structural and Molecular Biology, University College London, UK
| | - Andy M Lau
- Department of Structural and Molecular Biology, University College London, UK
| | - Sharon M Kelly
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Kersti Karu
- Department of Chemistry, University College London, UK
| | - Jayesh Gor
- Department of Structural and Molecular Biology, University College London, UK
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, University College London, UK
| | | |
Collapse
|
2
|
Namkhah Z, Naeini F, Ostadrahimi A, Tutunchi H, Hosseinzadeh-Attar MJ. The association of the adipokine zinc-alpha2-glycoprotein with non-alcoholic fatty liver disease and related risk factors: A comprehensive systematic review. Int J Clin Pract 2021; 75:e13985. [PMID: 33404166 DOI: 10.1111/ijcp.13985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 01/03/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND AIM The adipokine zinc-alpha2-glycoprotein (ZAG), a multidisciplinary protein, is involved in lipid metabolism, glucose homeostasis and energy balance. Accumulating evidence demonstrates that the expression of ZAG is mainly downregulated in obesity and obesity-related conditions. In the present study, we assessed the association of ZAG with non-alcoholic fatty liver disease (NAFLD) and the related risk factors including obesity, metabolic factors and inflammatory parameters, with emphasis on potential mechanisms underlying these associations. METHODS PRISMA guidelines were followed in this review. Systematic searches were performed using the PubMed/Medline, ScienceDirect, Scopus, EMBASE, ProQuest and Google Scholar databases, up to August 2020 for all relevant published papers. RESULTS Out of 362 records screened, 34 articles were included in the final analysis. According to the studies reviewed here, ZAG appears to exert a protective effect against NAFLD by enhancing mRNA expression levels of peroxisome proliferator-activated receptor α (PPARα) and PPARγ, promoting mRNA expression levels of the lipolysis-related genes, reducing mRNA expression levels of the lipogenesis-related genes, increasing hepatic fatty acid oxidation, ameliorating hepatic steatosis, promoting the activity of brown adipose tissue and the expression of thermogenesis-related genes, modulating energy balance and glucose homeostasis, and elevating plasma levels of healthy adipokines such as adiponectin. ZAG can also be involved in the regulation of inflammatory responses by attenuation of the expression of pro-inflammatory and pro-fibrotic mediators. CONCLUSION According to the studies reviewed here, ZAG is suggested to be a promising therapeutic target for NAFLD. However, the favourable effects of ZAG need to be confirmed in prospective cohort studies.
Collapse
Affiliation(s)
- Zahra Namkhah
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Science, Tehran, Iran
| | - Fatemeh Naeini
- Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Science, Tehran, Iran
| | - Alireza Ostadrahimi
- Nutrition Research Center, Department of Clinical Nutrition, School of Nutrition & Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Helda Tutunchi
- Nutrition Research Center, Department of Clinical Nutrition, School of Nutrition & Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | | |
Collapse
|
3
|
New insights into the zinc-α2-glycoprotein (ZAG) scaffold and its metal ions binding abilities using spectroscopic techniques. Life Sci 2020; 249:117462. [PMID: 32097664 DOI: 10.1016/j.lfs.2020.117462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 11/20/2022]
Abstract
AIMS Zinc-α2-glycoprotein (ZAG) is soluble lipid mobilizing protein and a noval adipokine associated with cancer cachexia. ZAG is an omnipresent protein and represent a fold of MHC class I proteins. Although ZAG's metal binding capacity has already been reported, no other metal has been mapped to date besides the complex formation with zinc. MAIN METHODOLOGY In this study, fluorescence emission spectroscopy and mass spectrometry (MALDI-TOF) were employed to define the putative interaction sites and their accessibility for the biologically important metals of Irving William Series. KEY FINDINGS Several hotspot residues in the ZAG scaffold involved in these interactions were mapped and their binding affinity score for each metal has been determined. Thebinding abilities of these sites and aggregation propensities of ZAG were monitored by fluorescence emission spectroscopy. SIGNIFICANCE The prediction of such binding affinity with metals on the active sites and its impact on the conformational states to accelerate aggregation was discussed as an important finding that may be involved in several other biochemical processes such as lipid binding, β-adrenergic receptors, cancer cachexia and association with plasma cholesterol and obesity.
Collapse
|
4
|
Johar D, Ahmed SM, El Hayek S, Al-Dewik N, Bahbah EI, Omar NH, Mustafa M, Salman DO, Fahmey A, Mottawea M, Azouz RAM, Bernstein L. Diabetes-induced Proteome Changes Throughout Development. Endocr Metab Immune Disord Drug Targets 2020; 19:732-743. [PMID: 31038056 DOI: 10.2174/1871530319666190305153810] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/31/2018] [Accepted: 11/25/2018] [Indexed: 12/31/2022]
Abstract
BACKGROUND Diabetes Mellitus (DM) is a multisystemic disease involving the homeostasis of insulin secretion by the pancreatic islet beta cells (β-cells). It is associated with hypertension, renal disease, and arterial and arteriolar vascular diseases. DISCUSSION The classification of diabetes is identified as type 1 (gene linked β-cell destruction in childhood) and type 2 (late onset associated with β-cell overload and insulin resistance in peripheral tissues. Type 1 diabetes is characterized by insulin deficiency, type 2 diabetes by both insulin deficiency and insulin resistance. The former is a genetically programmed loss of insulin secretion whereas the latter constitutes a disruption of the homeostatic relationship between the opposing activity of β- cell insulin and alpha cell (α-cell) glucagon of the Islets of Langerhans. The condition could also occur in pregnancy, as a prenatal occurring event, possibly triggered by the hormonal changes of pregnancy combined with β-cell overload. This review discusses the molecular basis of the biomolecular changes that occur with respect to glucose homeostasis and related diseases in DM. The underlying link between pancreatic, renal, and microvascular diseases in DM is based on oxidative stress and the Unfolded Protein Response (UPR). CONCLUSION Studying proteome changes in diabetes can deepen our understanding of the biomolecular basis of disease and help us acquire more efficient therapies.
Collapse
Affiliation(s)
- Dina Johar
- Biomedical Science Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt and Biochemistry and Nutrition Department, Ain Shams University Faculty of Women for Arts, Sciences and Education, Heliopolis, Cairo, Egypt
| | - Sara M Ahmed
- Clinical Pathology Department, Faculty of Medicine (Girls), Al-Azhar University, Nasr City, Cairo, Egypt
| | - Samer El Hayek
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Nader Al-Dewik
- Qatar Medical Genetic Center, Pediatrics Department, Hamad General Hospital (HGH), Hamad Medical Corporation (HMC), Doha, Qatar
| | - Eshak I Bahbah
- Faculty of Medicine, Al-Azhar University, Damietta, P.C. 34511, Egypt
| | - Nabil H Omar
- Pharmacy Department, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha, Qatar
| | | | - Doaa O Salman
- Genetics Unit, Histology and Cell biology department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Asmaa Fahmey
- Faculty of Pharmacy, Al-Mansoura University, Al-Mansoura, Egypt
| | - Mohamed Mottawea
- Faculty of Pharmacy, Modern University for Technology and Information, Cairo, Egypt
| | - Rasha A M Azouz
- Molecular Biology Department, Genetic Engineering and Biotechnology Research Division, National Research Centre, Dokki, 12622 Giza, Egypt
| | - Larry Bernstein
- Triplex Consulting, 54 Firethorn Lane, Northampton, MA 01060, United States
| |
Collapse
|
5
|
Crystal structure of zinc-α2-glycoprotein in complex with a fatty acid reveals multiple different modes of protein-lipid binding. Biochem J 2019; 476:2815-2834. [PMID: 31506272 DOI: 10.1042/bcj20190354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/06/2019] [Accepted: 09/10/2019] [Indexed: 12/14/2022]
Abstract
Human zinc-α2-glycoprotein (ZAG) is a 42 kDa adipokine which regulates body fat mass and is associated with cachexia and obesity. ZAG belongs to the major histocompatibility complex class I protein family and binds long-chain polyunsaturated fatty acids in its groove formed from the α1 and α2 domains. To identify the molecular basis of its lipid-binding function, we determined the first crystal structure at 2.49 Å resolution for fatty acid-bound ZAG, where the ligand was the fluorescent 11-(dansylamino)undecanoic acid (DAUDA). The 192 kDa crystallographic asymmetric unit contained six ZAG and eight fatty acid molecules in unique conformations. Six fatty acid molecules were localised to the ZAG grooves, where their tails were bound in two distinct conformations. The carboxylate groups of three fatty acids projected out of the groove, while the fourth was hydrogen bonded with R73 inside the groove. Other ligand-residue contacts were primarily hydrophobic. A new fatty acid site was revealed for two further DAUDA molecules at the ZAG α3 domains. Following conformational changes from unbound ZAG, the α3 domains formed tetrameric β-barrel structures lined by fatty acid molecules that doubled the binding capacity of ZAG. Analytical ultracentrifugation revealed that ZAG in solution was a monomer in the absence of DAUDA, but formed small amounts of tetramers with DAUDA. By showing that ZAG binds fatty acids in different locations, we demonstrate an augmented mechanism for fatty acid binding in ZAG that is distinct from other known fatty acid binding proteins, and may be relevant to cachexia.
Collapse
|
6
|
Thippakorn C, Schaduangrat N, Nantasenamat C. Proteomic and bioinformatic discovery of biomarkers for diabetic nephropathy. EXCLI JOURNAL 2018; 17:312-330. [PMID: 29805343 PMCID: PMC5962897 DOI: 10.17179/excli2018-1150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/12/2018] [Indexed: 11/13/2022]
Abstract
Diabetes is associated with numerous metabolic and vascular risk factors that contribute to a high rate of micro-vascular and macro-vascular disorders leading to mortality and morbidity from diabetic complications. In this case, the major cause of death in overall diabetic patients results from diabetic nephropathy (DN) or renal failure. The risk factors and mechanisms that correspond to the development of DN are not fully understood and so far, no specific and sufficient diagnostic biomarkers are currently available other than micro- or macroalbuminuria. Therefore, this review describes current and novel protein biomarkers in the context of DN as well as probable proteins biomarkers associated with pathological processes for the early stage of DN via proteomics data together with bioinformatics. In addition, the mechanisms involved in early development of diabetic vascular disorders and complications resulting from glucose induced oxidative stress will also be explored.
Collapse
Affiliation(s)
- Chadinee Thippakorn
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Nalini Schaduangrat
- Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Chanin Nantasenamat
- Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| |
Collapse
|
7
|
Singh H, Yu Y, Suh MJ, Torralba MG, Stenzel RD, Tovchigrechko A, Thovarai V, Harkins DM, Rajagopala SV, Osborne W, Cogen FR, Kaplowitz PB, Nelson KE, Madupu R, Pieper R. Type 1 Diabetes: Urinary Proteomics and Protein Network Analysis Support Perturbation of Lysosomal Function. Theranostics 2017; 7:2704-2717. [PMID: 28819457 PMCID: PMC5558563 DOI: 10.7150/thno.19679] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/25/2017] [Indexed: 12/11/2022] Open
Abstract
While insulin replacement therapy restores the health and prevents the onset of diabetic complications (DC) for many decades, some T1D patients have elevated hemoglobin A1c values suggesting poor glycemic control, a risk factor of DC. We surveyed the stool microbiome and urinary proteome of a cohort of 220 adolescents and children, half of which had lived with T1D for an average of 7 years and half of which were healthy siblings. Phylogenetic analysis of the 16S rRNA gene did not reveal significant differences in gut microbial alpha-diversity comparing the two cohorts. The urinary proteome of T1D patients revealed increased abundances of several lysosomal proteins that correlated with elevated HbA1c values. In silico protein network analysis linked such proteins to extracellular matrix components and the glycoprotein LRG1. LRG1 is a prominent inflammation and neovascularization biomarker. We hypothesize that these changes implicate aberrant glycation of macromolecules that alter lysosomal function and metabolism in renal tubular epithelial cells, cells that line part of the upper urinary tract.
Collapse
|
8
|
Peterson RA, Gueniche A, Adam de Beaumais S, Breton L, Dalko-Csiba M, Packer NH. Sweating the small stuff: Glycoproteins in human sweat and their unexplored potential for microbial adhesion. Glycobiology 2015; 26:218-29. [DOI: 10.1093/glycob/cwv102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022] Open
|
9
|
Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites. Biochem J 2015; 473:43-54. [PMID: 26487699 DOI: 10.1042/bj20150836] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/20/2015] [Indexed: 02/07/2023]
Abstract
Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.
Collapse
|
10
|
Kumar AA, Hati D, Thaker TM, Miah L, Cunningham P, Domene C, Bui TTT, Drake AF, McDermott LC. Strong and weak zinc binding sites in human zinc-α2-glycoprotein. FEBS Lett 2013; 587:3949-54. [PMID: 24188824 DOI: 10.1016/j.febslet.2013.10.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/22/2013] [Indexed: 11/24/2022]
Abstract
Zinc-α2-glycoprotein (ZAG) is an adipokine with an MHC class I-like protein fold. Even though zinc causes ZAG to precipitate from plasma during protein purification, no zinc binding has been identified to date. Using mass spectrometry, we demonstrated that ZAG contains one strongly bound zinc ion, predicted to lie close to the α1 and α2 helical groove. UV, CD and fluorescence spectroscopies detected weak zinc binding to holo-ZAG, which can bind up to 15 zinc ions. Zinc binding to 11-(dansylamino) undecanoic acid was enhanced by holo-ZAG. Zinc binding may be important for ZAG binding to fatty acids and the β-adrenergic receptor.
Collapse
Affiliation(s)
- Aditya Arun Kumar
- Department of Biochemistry, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Adams EJ, Luoma AM. The adaptable major histocompatibility complex (MHC) fold: structure and function of nonclassical and MHC class I-like molecules. Annu Rev Immunol 2013; 31:529-61. [PMID: 23298204 DOI: 10.1146/annurev-immunol-032712-095912] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The MHC fold is found in proteins that have a range of functions in the maintenance of an organism's health, from immune regulation to fat metabolism. Well adapted for antigen presentation, as seen for peptides in the classical MHC molecules and for lipids in CD1 molecules, the MHC fold has also been modified to perform Fc-receptor activity (e.g., FcRn) and for roles in host homeostasis (e.g., with HFE and ZAG). The more divergent MHC-like molecules, such as some of those that interact with the NKG2D receptor, represent the minimal MHC fold, doing away with the α3 domain and β2m while maintaining the α1/α2 platform domain for receptor engagement. Viruses have also co-opted the MHC fold for immune-evasive functions. The variations on the theme of a β-sheet topped by two semiparallel α-helices are discussed in this review, highlighting the fantastic adaptability of this fold for good and for bad.
Collapse
Affiliation(s)
- Erin J Adams
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA.
| | | |
Collapse
|
12
|
McDermott L, Jadoon A, Cunningham P. ZAG and a potential role in systemic lipid homeostastis: examining the evidence from in vitro human studies and patients with chronic illness. ACTA ACUST UNITED AC 2012. [DOI: 10.2217/clp.12.45] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
13
|
Bagherani N. The Newest Hypothesis about Vitiligo: Most of the Suggested Pathogeneses of Vitiligo Can Be Attributed to Lack of One Factor, Zinc-α2-Glycoprotein. ISRN DERMATOLOGY 2012; 2012:405268. [PMID: 22778983 PMCID: PMC3388346 DOI: 10.5402/2012/405268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 04/18/2012] [Indexed: 11/23/2022]
Abstract
Zinc-α2-glycoprotein (ZAG) is a recently identified adipokine, assigned to the chromosome 7q22.1. It is a multidisciplinary protein, which is secreted in various body fluids. The ZAG plays roles in lipolysis, regulation of metabolism, cell proliferation and differentiation, regulation of melanin synthesis, cell adhesion, immunoregulation, and so forth. Vitiligo is the most common depigmenting skin disorder, characterized by acquired, progressive, and circumscribed amelanosis of the skin and hair. It commonly begins in childhood or young adulthood. The pathogenesis of this disorder is uncertain, but it appears to be dependent on the interaction of genetic, immunological, and neurological factors. For the first time, we pointed the probable association between ZAG and vitiligo. Herein, I have described this association in different views. By confirming this association, a surprising progression will occur in the treatment of this prevalent debilitating disease.
Collapse
Affiliation(s)
- Nooshin Bagherani
- Nooshin Bagherani's Office, 2nd Floor, Taha Physicians' Building, 40-Meter Street, Khoramshahr, Khuzestan Province, Iran
| |
Collapse
|
14
|
Wang F, Huang L, Na N, He D, Sun D, Ouyang J. The development of simple and sensitive small-molecule fluorescent probes for the detection of serum proteins after native polyacrylamide gel electrophoresis. Analyst 2012; 137:2367-73. [PMID: 22475746 DOI: 10.1039/c2an35265f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper, a simple and sensitive small-molecule fluorescent probe, 2,5-dihydroxy-4'-dimethylaminochalcone (DHDMAC), was designed and synthesized for the detection of human serum proteins via hydrophobic interactions after polyacrylamide gel electrophoresis (PAGE). This probe produced lower fluorescence emission in the absence of proteins, and the emission intensity was significantly increased after the interaction with serum proteins. To demonstrate the imaging performance of this probe as a fluorescent dye, a series of experiments was conducted that included sensitivity comparison and 2D-PAGE. The results indicated that the sensitivity of DHDMAC staining is comparable to that of the most widely used fluorescent dye, SYPRO Ruby, and more protein spots (including thyroxine-binding globulin, angiotensinogen, afamin, zinc-α-2-glycoprotein and α-1-antichymotrypsin) were detected after 2D-PAGE. Therefore, DHDMAC is a good protein reporter due to its fast staining procedure, low detection limits and high resolution.
Collapse
Affiliation(s)
- Fangfang Wang
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | | | | | | | | | | |
Collapse
|
15
|
Mracek T, Stephens NA, Gao D, Bao Y, Ross JA, Rydén M, Arner P, Trayhurn P, Fearon KCH, Bing C. Enhanced ZAG production by subcutaneous adipose tissue is linked to weight loss in gastrointestinal cancer patients. Br J Cancer 2011; 104:441-7. [PMID: 21245862 PMCID: PMC3049573 DOI: 10.1038/sj.bjc.6606083] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background: Profound loss of adipose tissue is a hallmark of cancer cachexia. Zinc-α2-glycoprotein (ZAG), a recently identified adipokine, is suggested as a candidate in lipid catabolism. Methods: In the first study, eight weight-stable and 17 cachectic cancer patients (weight loss ⩾5% in previous 6 months) were recruited. Zinc-α2-glycoprotein mRNA and protein expression were assessed in subcutaneous adipose tissue (SAT), subcutaneous adipose tissue morphology was examined and serum ZAG concentrations were quantified. In the second cohort, ZAG release by SAT was determined in 18 weight-stable and 15 cachectic cancer patients. The effect of ZAG on lipolysis was evaluated in vitro. Results: Subcutaneous adipose tissue remodelling in cancer cachexia was evident through shrunken adipocytes with increased fibrosis. In cachectic cancer patients, ZAG mRNA was upregulated (2.7-fold, P=0.028) while leptin mRNA decreased (2.2-fold, P=0.018); serum ZAG levels were found to be unaffected. Zinc-α2-glycoprotein mRNA correlated positively with weight loss (r=0.51, P=0.01) and serum glycerol levels (r=0.57, P=0.003). Zinc-α2-glycoprotein release by SAT was also elevated in cachectic patients (1.5-fold, P=0.024) and correlated with weight loss (r=0.50, P=0.003). Recombinant ZAG stimulated lipolysis in human adipocytes. Conclusions: Zinc-α2-glycoprotein expression and secretion by adipose tissue is enhanced in cachectic cancer patients. Given its lipid-mobilising effect, ZAG may contribute to adipose atrophy associated with cancer cachexia in human beings.
Collapse
Affiliation(s)
- T Mracek
- Obesity Biology Research Unit, School of Clinical Sciences, University of Liverpool, Liverpool L69 3GA, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Hassan I, Ahmad F. Structural diversity of class I MHC-like molecules and its implications in binding specificities. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2011; 83:223-70. [PMID: 21570669 DOI: 10.1016/b978-0-12-381262-9.00006-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The binding groove of class I major histocompatibility complex (MHC) class is essentially important for antigen binding and presentation on T cells. There are several molecules that have analogous conformations to class I MHC. However, they bind specifically to varying types of ligands and cell-surface receptors in order to elicit an immune response. To elucidate how such recognition is achieved in classical MHC-I like molecules, we have extensively analyzed the structure of human leukocyte antigen (HLA-1), neonatal Fc receptor (FcRn), hereditary hemochromatosis protein (HFE), cluster of differentiation 1 (CD1), gamma delta T cell receptor ligand (Τ22), zinc-α2-glycoprotein (ZAG), and MHC class I chain-related (MIC-A) proteins. All these molecules have analogous structural anatomy, divided into three distinct domains, where α1-α2 superdomains form a groove-like structure that potentially bind to certain ligand, while the α3 domain adopts a fold resembling immunoglobulin constant domains, and holds this α1-α2 platform and the light chain. We have observed many remarkable features of α1-α2 platform, which provide specificities to these proteins toward a particular class of ligands. The relative orientation of α1, α2, and α3 domains is primarily responsible for the specificity to the light chain. Interestingly, light chain of all these proteins is β₂-microglobulin (β₂M), except ZAG which has prolactin-induced protein (PIP). However, MIC-A is devoid of any light chain. Residues on β₂M recognize a sequence motif on the α3 domain that is essentially restricted to specific heavy chain of MHC class I molecules. Our analysis suggests that the structural features of class I molecules determine the recognition of different ligands and light chains, which are responsible for their corresponding functions through an inherent mechanism.
Collapse
Affiliation(s)
- Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | | |
Collapse
|
17
|
Markó L, Szigeti N, Szabó Z, Böddi K, Takátsy A, Ludány A, Koszegi T, Molnár GA, Wittmann I. Potential urinary biomarkers of disease activity in Crohn's disease. Scand J Gastroenterol 2010; 45:1440-8. [PMID: 20653491 DOI: 10.3109/00365521.2010.505658] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Measurement of the immunoreactive urinary albumin (ir-uAlb) concentration by immunological methods was found to be an effective method to identify disease activity in Crohn's disease (CD). Recently a size-exclusion (SE) high performance liquid chromatography (HPLC) method was developed to measure both ir-uAlb and non-immunoreactive urinary albumin (total, t-uAlb). We aimed to follow-up one of our CD patients with frequent remissions and exacerbation phases comparing the changes of disease activity parameters and the concentration of ir-uAlb and t-uAlb. The surprising results led us to perform measurements in greater depth. MATERIAL AND METHODS Concentration of ir-uAlb was measured by immunoturbidimetry (IT) and t-uAlb by SE-HPLC. Albumin peak of SE-HPLC was collected and applied to a reversed-phase (RP) HPLC and to gel-electrophoresis. Eluted peaks of RP-HPLC and identified bands of gel-electrophoresis were analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). RESULTS The concentration of t-uAlb was 15 times higher than that of the ir-uAlb during active state. The RP-HPLC and the gel-electrophoresis separation proved that albumin peak by size-exclusion consists of three different peaks. MALDI-TOF/MS measurements identified α1-acid-glycoprotein and Zn-α2-glycoprotein as major, and albumin as minor protein. CONCLUSIONS Peak of albumin of SE-HPLC contains a significant amount of glycoprotein during the active phase of CD, which could not be detected in remission. Urinary α1-acid-glycoprotein and/or Zn-α2-glycoprotein could be an ideal disease activity biomarker of CD.
Collapse
Affiliation(s)
- Lajos Markó
- 2nd Department of Medicine and Nephrological Center, University of Pécs, Faculty of Medicine, Pécs, Hungary
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
The importance of white adipose tissue in the control of energy balance is now firmly recognized. In addition to fuel storage, adipocytes secrete an array of proteins factors (adipokines), which regulate multiple physiological and metabolic processes as well as influence body fat accumulation. Zinc-α2-glycoprotein (ZAG), a lipid mobilizing factor initially characterized as a tumor product associated with cachexia, has recently been identified as a novel adipokine. Although the exact role of ZAG in adipose tissue remains to be clarified, there is evidence that ZAG expression appears to be inversely related to adiposity, being upregulated in cachexia whereas reduced in obesity. Investigations on the regulation of ZAG give insights into its potential function in adipose tissue with a link to lipid mobilization and an anti-inflammatory action. Recent work shows that ZAG stimulates adiponectin secretion by human adipocytes. Data from genetic studies suggest that ZAG may be a candidate gene for body weight regulation; this is supported by the demonstration that ZAG-knockout mice are susceptible to weight gain, whereas transgenic mice overexpressing ZAG exhibit weight loss. The present review summarizes these new perspectives of ZAG and the potential mechanisms by which it might modulate adipose tissue mass and function.
Collapse
|
19
|
Mracek T, Gao D, Tzanavari T, Bao Y, Xiao X, Stocker C, Trayhurn P, Bing C. Downregulation of zinc-{alpha}2-glycoprotein in adipose tissue and liver of obese ob/ob mice and by tumour necrosis factor-alpha in adipocytes. J Endocrinol 2010; 204:165-72. [PMID: 19934249 PMCID: PMC2807359 DOI: 10.1677/joe-09-0299] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Zinc-alpha2-glycoprotein (ZAG, also listed as AZGP1 in the MGI Database), a lipid-mobilising factor, has recently been suggested as a potential candidate in the modulation of body weight. We investigated the effect of increased adiposity on ZAG expression in adipose tissue and the liver and on plasma levels in obese (ob/ob) mice compared with lean siblings. The study also examined the effect of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNFalpha) on ZAG expression in adipocytes. Zag mRNA levels were significantly reduced in subcutaneous (fourfold) and epididymal (eightfold) fat of ob/ob mice. Consistently, ZAG protein content was decreased in both fat depots of ob/ob mice. In the liver of obese animals, steatosis was accompanied by the fall of both Zag mRNA (twofold) and ZAG protein content (2.5-fold). Plasma ZAG levels were also decreased in obese mice. In addition, Zag mRNA was reduced in epididymal (fivefold) and retroperitoneal (fivefold) adipose tissue of obese (fa/fa) Zucker rats. In contrast to Zag expression, Tnfalpha mRNA levels were elevated in adipose tissue (twofold) and the liver (2.5-fold) of ob/ob mice. Treatment with TNFalpha reduced Zag gene expression in differentiated adipocytes, and this inhibition was chronic, occurring at 24 and 48 h following TNFalpha treatment. It is concluded that ZAG synthesis in adipose tissue and the liver is downregulated, as are its circulating levels, in ob/ob mice. The reduced ZAG production may advance the susceptibility to lipid accumulation in these tissues in obesity, and this could be at least in part attributable to the inhibitory effect of TNFalpha.
Collapse
Affiliation(s)
| | | | | | | | | | - C Stocker
- Clore LaboratoryUniversity of BuckinghamBuckingham, MK18 1EGUK
| | | | - C Bing
- (Correspondence should be addressed to C Bing; )
| |
Collapse
|
20
|
Guo YK, Chen H, Zhang B, Pan CY, Zhang LZ, Zhao M, Zhang CF, Lan XY, Wang JQ. [Polymorphisms of ZAG gene with growth traits in Jiaxian red cattle]. YI CHUAN = HEREDITAS 2008; 30:1417-20. [PMID: 19073549 DOI: 10.3724/sp.j.1005.2008.01417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The main function of ZAG gene is to enable the decomposition of fat, and reduced fat content. In this study, polymorphisms of four loci (Z1, Z2, Z3, Z4) at the coding region of the bovine ZAG gene were detected in 145 Jiaxian red cattle, and polymorphisms were found on Z1, Z3, Z4 loci. The fragments showing different SSCP patterns were sequenced, nd a total of six SNPs (C115T, A3257G, A4013G, T4027C, C4032T, and T4120C) were found. The Z3 locus of ZAG gene was at Hardy-Weinberg equilibrium, while Z1 and Z4 loci of ZAG gene were not at Hardy-Weinberg disequilibrium. The association analysis of different genotypes with some of the growth and development traits showed that the individuals with genotype AC had a larger body length, heart girth, circumference of cannon bone, body weight than the individuals with genotypes AA and AB (P<0.05 or P<0.01, respectively) in Z4 locus. It is suggest that Z4 locus may be one of the marker-assisted selection used as growth traits in Jiaxian red cattle.
Collapse
Affiliation(s)
- Yi-Kun Guo
- College of Animal Science and Technology, Northwest A & F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling, Shaanxi 712100, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Hassan MI, Bilgrami S, Kumar V, Singh N, Yadav S, Kaur P, Singh TP. Crystal structure of the novel complex formed between zinc alpha2-glycoprotein (ZAG) and prolactin-inducible protein (PIP) from human seminal plasma. J Mol Biol 2008; 384:663-72. [PMID: 18930737 DOI: 10.1016/j.jmb.2008.09.072] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 09/19/2008] [Accepted: 09/23/2008] [Indexed: 10/21/2022]
Abstract
This is the first report on the formation of a complex between zinc alpha2-glycoprotein (ZAG) and prolactin-inducible protein (PIP). The complex was purified from human seminal plasma and crystallized using 20% polyethylene glycol 9000 and 5% hexaethylene glycol. The structure of the complex has been determined using X-ray crystallographic method and refined to an R(cryst) of 0.199 (R(free)=0.239). The structure of ZAG is broadly similar to the structure of serum ZAG. The scaffolding of PIP consists of seven beta-strands that are organized in the form of two antiparallel beta-pleated sheets, resulting in the formation of a sandwiched beta-sheet. The amino acid sequence of PIP contains one potential N-glycosylation site at Asn77, and the same is found glycosylated with four sugar residues. The structure of the complex shows that the beta-structure of PIP is ideally aligned with the beta-structure of domain alpha3 of ZAG to form a long interface between two proteins. The proximal beta-strands at the long interface are arranged in an antiparallel manner. There are 12 hydrogen bonds and three salt bridges between ZAG and PIP. At the two ends of vertical interface, two salt bridges are formed between pairs of Lys41-Asp233 and Lys68-Glu229. On the perpendicular interface involving alpha1-alpha2 domains of ZAG and a loop of PIP, another salt bridge is formed. The internal space at the corner of the L-shaped structure is filled with solvent molecules including a carbonate ion. The overall buried area in the complex is approximately 914 A(2), which is considerably higher than the 660 A(2) reported for the class I major histocompatibility complex structures.
Collapse
Affiliation(s)
- Md Imtaiyaz Hassan
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India
| | | | | | | | | | | | | |
Collapse
|
22
|
Schmitt R, Marlier A, Cantley LG. Zag expression during aging suppresses proliferation after kidney injury. J Am Soc Nephrol 2008; 19:2375-83. [PMID: 18815245 DOI: 10.1681/asn.2008010035] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Recovery after acute kidney injury is impaired in the elderly, but mechanistic information regarding why this occurs is limited. In this study, aged mouse kidneys displayed a reduced epithelial proliferative reserve in vivo and in vitro. Microarray analysis identified increased expression of zinc-alpha (2)-glycoprotein (Zag) in aged proximal tubular cells. The addition of recombinant Zag to primary renal epithelial cell cultures decreased proliferation, whereas knockdown of Zag increased proliferation. In vivo, systemic small interference RNA suppressed expression of Zag in the mouse proximal tubule; this increased the rate of epithelial cell proliferation after renal ischemia/reperfusion in aged mice but also increased parenchymal fibrosis. These results demonstrate that increased Zag expression in the aged kidney acts to suppress the proliferative response to injury and introduce Zag as a modifier of the aging phenotype.
Collapse
Affiliation(s)
- Roland Schmitt
- Section of Nephrology, Department of Medicine, Yale University, New Haven, Connecticut 06510, USA
| | | | | |
Collapse
|
23
|
Hassan MI, Waheed A, Yadav S, Singh TP, Ahmad F. Zinc alpha 2-glycoprotein: a multidisciplinary protein. Mol Cancer Res 2008; 6:892-906. [PMID: 18567794 DOI: 10.1158/1541-7786.mcr-07-2195] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Zinc alpha 2-glycoprotein (ZAG) is a protein of interest because of its ability to play many important functions in the human body, including fertilization and lipid mobilization. After the discovery of this molecule, during the last 5 decades, various studies have been documented on its structure and functions, but still, it is considered as a protein with an unknown function. Its expression is regulated by glucocorticoids. Due to its high sequence homology with lipid-mobilizing factor and high expression in cancer cachexia, it is considered as a novel adipokine. On the other hand, structural organization and fold is similar to MHC class I antigen-presenting molecule; hence, ZAG may have a role in the expression of the immune response. The function of ZAG under physiologic and cancerous conditions remains mysterious but is considered as a tumor biomarker for various carcinomas. There are several unrelated functions that are attributed to ZAG, such as RNase activity, regulation of melanin production, hindering tumor proliferation, and transport of nephritic by-products. This article deals with the discussion of the major aspects of ZAG from its gene structure to function and metabolism.
Collapse
Affiliation(s)
- Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi 110025, India
| | | | | | | | | |
Collapse
|
24
|
Hassan MI, Kumar V, Singh TP, Yadav S. Purification and characterization of zinc α2‐glycoprotein‐Prolactin inducible protein complex from human seminal plasma. J Sep Sci 2008; 31:2318-24. [DOI: 10.1002/jssc.200700686] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
25
|
Analysis of the transthyretin-like (TTL) gene family in Ostertagia ostertagi--comparison with other strongylid nematodes and Caenorhabditis elegans. Int J Parasitol 2008; 38:1545-56. [PMID: 18571174 DOI: 10.1016/j.ijpara.2008.04.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 04/07/2008] [Accepted: 04/10/2008] [Indexed: 11/21/2022]
Abstract
The transthyretin-like (ttl) gene family is one of the largest conserved nematode-specific gene families, coding for a group of proteins with significant sequence similarity to transthyretins (TTR) and transthyretin-related proteins (TRP). In the present study, we investigated the ttl family in Ostertagia ostertagi (a nematode of the abomasum of cattle). Mining of expressed sequence tag (EST) databases revealed the presence of at least 18 ttl genes in O. ostertagi (Oo-ttl), most of which are constitutively transcribed from the free-living, third larval stage onwards. The full-length cDNA of one of these genes (Oo-ttl-1) was amplified and cloned for recombinant expression. Western blot analysis using a specific antiserum showed that the native protein Oo-TTL-1 was highly present in the excretory-secretory (ES) products of adults of O. ostertagi. The protein was immunolocalized to the pseudocoelomic fluid of adult worms. A phylogenetic-bioinformatic analysis of all amino acid sequence data for TTL proteins from a range of strongylid nematodes showed that they could be divided into at least five different classes. This classification was based on conserved amino acids in the first TTL signature domain and the number and location of cysteine residues. The biological role(s) of the TTLs in nematode biology is still unclear. A theoretical three-dimensional model of Oo-TTL-1 indicated that it had a similar structure to TTRs (i.e., containing β-sheets, arranged in a β-sandwich). In contrast to TTRs, competitive binding studies using recombinant Oo-TTL-1 indicated that the protein was devoid of any hydrophobic ligand- or thyroid hormone-binding properties. Finally, combinatorial analysis by double-stranded RNA interference of five ttl genes in the free-living nematode Caenorhabditis elegans did not reveal any visible phenotypes. More information on the transcription profile and tissue distribution of TTLs in nematodes is needed to provide new insights into the biological role of this gene family.
Collapse
|
26
|
Qu F, Ying X, Guo W, Guo Q, Chen G, Liu Y, Ding Z. The role of Zn-alpha2 glycoprotein in sperm motility is mediated by changes in cyclic AMP. Reproduction 2007; 134:569-76. [PMID: 17890292 DOI: 10.1530/rep-07-0145] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sperm motility is essential for male reproduction or natural fertilization. The cyclic AMP (cAMP)/cAMP-dependent protein kinase A (PKA) signaling pathway is generally recognized as one of the significant signaling pathways in the regulation of mammalian spermatozoan motility. Since Zn-alpha2-glycoprotein (ZAG) activity in mammalian adipose tissue is mediated via the beta(3)-adrenoreceptor, with upregulation of the cAMP pathway, we hypothesize that ZAG may play the same role in sperm motility regulation, a new factor of regulation of sperm motility. Therefore, the gene encoding human ZAG was cloned and polyclonal antibodies were generated, and then laser scanning confocal microscopy and flow cytometry were employed to identify this protein in human spermatozoa. The results showed that ZAG protein was mostly localized on the pre-equatorial region covering the acrosome, neck, and middle piece of the flagellum of spermatozoa. Furthermore, using computer-assisted sperm analysis, we found that anti-human ZAG antibodies could significantly reduce the motility of human swim-up spermatozoa after 90- or 120-min incubation (P<0.05 and P<0.01 respectively), together with the decreasing of intracellular cAMP and PKA levels. In conclusion, these data suggest that ZAG is present in human spermatozoa and may be involved in the regulation of sperm motility via the cAMP/PKA signaling pathway.
Collapse
Affiliation(s)
- Fei Qu
- Shanghai Key Laboratory for Reproductive Medicine, Department of Histology and Embryology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | | | | | | | | | | | | |
Collapse
|
27
|
Stejskal D, Karpísek M, Reutová H, Stejskal P, Kotolová H, Kollár P. Determination of serum zinc-alpha-2-glycoprotein in patients with metabolic syndrome by a new ELISA. Clin Biochem 2007; 41:313-6. [PMID: 18078816 DOI: 10.1016/j.clinbiochem.2007.11.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 11/16/2007] [Accepted: 11/18/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To develop an assay for the determination of ZAG in human serum, and to investigate its clinical relevance as a marker of metabolic syndrome. DESIGN AND METHODS A new sandwich ELISA was introduced and clinically tested. RESULTS ZAG serum level did not differentiate healthy subjects (27.4+/-8.3 mg/L; N=132) from patients with metabolic syndrome (24.9+/-8.1; N=92). ZAG correlated with glucose, creatinine and uric acid. CONCLUSION The immunoassay offers a new research tool for glucose metabolism.
Collapse
Affiliation(s)
- D Stejskal
- Department of Laboratory Medicine and Department of Medicine, Sternberk Hospital, Jivavská 20, Sternberk, Czech Republic.
| | | | | | | | | | | |
Collapse
|
28
|
Ding Z, Qu F, Guo W, Ying X, Wu M, Zhang Y. Identification of sperm forward motility-related proteins in human seminal plasma. Mol Reprod Dev 2007; 74:1124-31. [PMID: 17393427 DOI: 10.1002/mrd.20624] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Seminal plasma, an amorphous material that exists in semen, contains proteins related to sperm forward motility. Employing affinity chromatography with ConA beads and protein ultrafiltration, we isolated and concentrated proteins from heated human seminal plasma. Results of computer-assisted semen analyses (CASA) demonstrated that the forward motility index of bovine spermatozoa from the epididymal caput, incubated with proteins and theophylline, was significantly different from that of spermatozoa incubated with theophylline alone (P < 0.01). The electrophoreses revealed that the protein bands with high molecular weights in the gel of PAGE changed into low molecular weights in the gel of SDS-PAGE. Furthermore, proteins from a separated portion of the PAGE gel were still able to stimulate spermatozoa from the epididymal caput to gain forward motility. Two-dimensional (2D)-gel electrophoresis and mass spectrometry indicated that spots focused on the portion seemed, according to their amino acid sequences, to be like human alpha-1-antitrypsin and zinc-alpha-2-glycoprotein (ZAG) precursors. Western blot analysis showed the presence of these two proteins in seminal plasma. These proteins, related to the forward motility of spermatozoa in human seminal plasma, may play important roles during maturation of spermatozoa, from the epididymis through fertilization in the female reproductive tract.
Collapse
Affiliation(s)
- Zhide Ding
- Department of Histology and Embryology, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory for Reproductive Medicine, Shanghai, China.
| | | | | | | | | | | |
Collapse
|
29
|
Rolli V, Radosavljevic M, Astier V, Macquin C, Castan-Laurell I, Visentin V, Guigné C, Carpéné C, Valet P, Gilfillan S, Bahram S. Lipolysis is altered in MHC class I zinc-α2-glycoprotein deficient mice. FEBS Lett 2007; 581:394-400. [PMID: 17234189 DOI: 10.1016/j.febslet.2006.12.047] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/17/2006] [Accepted: 12/20/2006] [Indexed: 11/28/2022]
Abstract
Non-conventional major histocompatibility complex class I molecules are involved in a variety of physiological functions, most at the periphery of the immune system per se. Zinc-alpha(2)-glycoprotein (ZAG), the sole soluble member of this superfamily has been implicated in cachexia, a poorly understood yet life-threatening, severe wasting syndrome. To further ascertain the role of ZAG in lipid metabolism and perhaps the immune system, we inactivated both ZAG alleles by gene targeting in mice. Subjecting these ZAG deficient animals to standard or lipid rich food regimens led to increased body weight in comparison to identically treated wild-type mice. This phenotype appeared to correlate with a significant decrease in adipocytic lipolysis that could not be rescued by several pharmacological agents including beta(3)-adrenoreceptor agonists. Furthermore, in contrast to previously reported data, ZAG was found to be ubiquitously and constitutively expressed, with an especially high level in the mouse liver. No overt immunological phenotype was identified in these animals.
Collapse
Affiliation(s)
- Véronique Rolli
- Immunogénétique Moléculaire Humaine, Centre de Recherche d'Immunologie et d'Hématologie, Faculté de Médecine, Hôpitaux Universitaires de Strasbourg, 4 Rue Kirschleger, 67085 Strasbourg Cedex, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|