1
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Guo H, Li J, Lu P. Systematic review and meta-analysis of mass spectrometry proteomics applied to ocular fluids to assess potential biomarkers of age-related macular degeneration. BMC Ophthalmol 2023; 23:507. [PMID: 38087257 PMCID: PMC10717315 DOI: 10.1186/s12886-023-03237-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is a significant cause of severe vision loss. The main purpose of this study was to identify mass spectrometry proteomics-based potential biomarkers of AMD that contribute to understanding the mechanisms of disease and aiding in early diagnosis. METHODS This study retrieved studies that aim to detect differences relate to proteomics in AMD patients and healthy control groups by mass spectrometry (MS) proteomics approaches. The search process was accord with PRISMA guidelines (PROSPERO database: CRD42023388093). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes Pathway Analysis (KEGG) were performed on differentially expressed proteins (DEPs) in the included articles using the DAVID database. DEPs were included in a meta-analysis when their effect size could be computed in at least two research studies. The effect size of measured proteins was transformed to the log2-fold change. Protein‒protein interaction (PPI) analysis was conducted on proteins that were statistically significant in the meta-analysis using the String online database. RESULTS Eleven studies fulfilled the inclusion criteria, and 161 DEPs were identified. The GO analysis showed that AMD is significantly related to proteolysis, extracellular exosome and protein binding. In KEGG, the most significant pathway was the complement and coagulation cascades. Meta-analysis results suggested that eight proteins were statistically significant, and according to PPI results, the most significant four proteins were serotransferrin (TF), apolipoprotein A1 (APOA1), complement C3 (C3) and lipocalin-1 (LCN1). CONCLUSIONS Four possible biomarkers, TF, APOA1, C3 and LCN1, were found to be significant in the pathogenesis of AMD and need to be further validated. Further studies should be performed to evaluate diagnostic and therapeutic value of these proteins.
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Affiliation(s)
- Hanmu Guo
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jianqing Li
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Peirong Lu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, China.
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2
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Prims S, Van Ostade X, Ayuso M, Dom M, Van Raemdonck G, Van Cruchten S, Casteleyn C, Van Ginneken C. Chronic exposure to multiple stressors alters the salivary proteome of piglets. PLoS One 2023; 18:e0286455. [PMID: 37235602 DOI: 10.1371/journal.pone.0286455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Monitoring chronic stress in pigs is not only essential in view of animal welfare but is also important for the farmer, given that stress influences the zootechnical performance of the pigs and increases their susceptibility to infectious diseases. To investigate the use of saliva as a non-invasive, objective chronic stress monitoring tool, twenty-four 4-day-old piglets were transferred to artificial brooders. At the age of 7 days, they were assigned to either the control or the stressed group and reared for three weeks. Piglets in the stressed group were exposed to overcrowding, absence of cage enrichment, and frequent mixing of animals between pens. Shotgun analysis using an isobaric labelling method (iTRAQ) for tandem mass spectrometry performed on saliva samples taken after three weeks of chronic stress identified 392 proteins, of which 20 proteins displayed significantly altered concentrations. From these 20 proteins, eight were selected for further validation using parallel reaction monitoring (PRM). For this validation, saliva samples that were taken one week after the start of the experiment and samples that were taken at the end of the experiment were analysed to verify the profile over time. We wanted to investigate whether the candidate biomarkers responded fast or rather slowly to the onset of chronic exposure to multiple stressors. Furthermore, this validation could indicate whether age influenced the baseline concentrations of these salivary proteins, both in healthy and stressed animals. This targeted PRM analysis confirmed that alpha-2-HS-glycoprotein was upregulated in the stressed group after one and three weeks, while odorant-binding protein, chitinase, long palate lung and nasal epithelium protein 5, lipocalin-1, and vomeromodulin-like protein were present in lower concentrations in the saliva of the stressed pigs, albeit only after three weeks. These results indicate that the porcine salivary proteome is altered by chronic exposure to multiple stressors. The affected proteins could be used as salivary biomarkers to identify welfare problems at the farm and facilitate research to optimise rearing conditions.
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Affiliation(s)
- Sara Prims
- Laboratory of Comparative Perinatal Development, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Xaveer Van Ostade
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signalling (PPES), Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- Center for Proteomics (CfP), University of Antwerp, Antwerp, Belgium
| | - Miriam Ayuso
- Laboratory of Comparative Perinatal Development, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Martin Dom
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signalling (PPES), Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Geert Van Raemdonck
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signalling (PPES), Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
- Center for Proteomics (CfP), University of Antwerp, Antwerp, Belgium
| | - Steven Van Cruchten
- Laboratory of Comparative Perinatal Development, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Christophe Casteleyn
- Laboratory of Comparative Perinatal Development, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
| | - Chris Van Ginneken
- Laboratory of Comparative Perinatal Development, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Antwerp, Belgium
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3
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Yang HH, Wang X, Li S, Liu Y, Akbar R, Fan GC. Lipocalin family proteins and their diverse roles in cardiovascular disease. Pharmacol Ther 2023; 244:108385. [PMID: 36966973 PMCID: PMC10079643 DOI: 10.1016/j.pharmthera.2023.108385] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 03/01/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023]
Abstract
The lipocalin (LCN) family members, a group of small extracellular proteins with 160-180 amino acids in length, can be detected in all kingdoms of life from bacteria to human beings. They are characterized by low similarity of amino acid sequence but highly conserved tertiary structures with an eight-stranded antiparallel β-barrel which forms a cup-shaped ligand binding pocket. In addition to bind small hydrophobic ligands (i.e., fatty acids, odorants, retinoids, and steroids) and transport them to specific cells, lipocalins (LCNs) can interact with specific cell membrane receptors to activate their downstream signaling pathways, and with soluble macromolecules to form the complex. Consequently, LCNs exhibit great functional diversity. Accumulating evidence has demonstrated that LCN family proteins exert multiple layers of function in the regulation of many physiological processes and human diseases (i.e., cancers, immune disorders, metabolic disease, neurological/psychiatric disorders, and cardiovascular disease). In this review, we firstly introduce the structural and sequence properties of LCNs. Next, six LCNs including apolipoprotein D (ApoD), ApoM, lipocalin 2 (LCN2), LCN10, retinol-binding protein 4 (RBP4), and Lipocalin-type prostaglandin D synthase (L-PGDS) which have been characterized so far are highlighted for their diagnostic/prognostic values and their potential effects on coronary artery disease and myocardial infarction injury. The roles of these 6 LCNs in cardiac hypertrophy, heart failure, diabetes-induced cardiac disorder, and septic cardiomyopathy are also summarized. Finally, their therapeutic potential for cardiovascular disease is discussed in each section.
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Affiliation(s)
- Hui-Hui Yang
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Xiaohong Wang
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Siru Li
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Yueying Liu
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Rubab Akbar
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Guo-Chang Fan
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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4
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Yang Y, Li F, Luo X, Jia B, Zhao X, Liu B, Gao R, Yang L, Wei W, He J. Identification of LCN1 as a Potential Biomarker for Breast Cancer by Bioinformatic Analysis. DNA Cell Biol 2019; 38:1088-1099. [PMID: 31424267 DOI: 10.1089/dna.2019.4843] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The biological functions of lipocalin-1 (LCN1) are involved in innate immune responses and act as a physiological scavenger of potentially harmful lipophilic molecules. However, the relevance of LCN1 with cancer is rarely concerned currently. The aim of this study is to address the relevance of LCN1 with BRCA by bioinformatics. In this study, we found that the expressions of LCN1 increased significantly in various cancerous tissues, including BRCA, compared with their adjacent normal tissues through the TIMER database. Furthermore, UALCAN database analysis showed that the expression of LCN1 increased gradually from stage 1 to stage 4 and was upregulated in BRCA patients with different races and subtypes compared with that in the normal. In addition, those patients with perimenopause and postmenopause status displayed higher LCN1 expression. Importantly, LCN1 genetic alterations, including copy number amplification, deep deletion, and missense mutation, could be found, and the alteration frequency showed difference in various invasive BRCA through cBioPortal database. Moreover, a positive correlation between LCN1 somatic copy number alterations and immune cell enrichments was revealed in basal like BRCA by GISTIC 2.0. Finally, analysis on prognostic value of LCN1 by Kaplan-Meier plotter showed that low LCN1 expression correlated with poor prognosis for relapse-free survival in all types of BRCA, overall survival in luminal B BRCA, distant metastasis free survival in human epithelial growth factor receptor-2 (HER2) positive BRCA, and postprogression survival (PPS) in luminal A BRCA. But high LCN1 expression also displayed poor prognosis for PPS in HER2 positive BRCA. The results together verified the significance of LCN1 in BRCA, suggesting that it may be a potential biomarker for BRCA diagnosis.
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Affiliation(s)
- Yuemei Yang
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China.,Department of R&D Technology Center, Beijing Zhicheng Biomedical Technology Co. Ltd., Beijing, P.R. China
| | - Feng Li
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
| | - Xueying Luo
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
| | - Binghan Jia
- Department of R&D Technology Center, Beijing Zhicheng Biomedical Technology Co. Ltd., Beijing, P.R. China
| | - Xiaoling Zhao
- Department of R&D Technology Center, Beijing Zhicheng Biomedical Technology Co. Ltd., Beijing, P.R. China
| | - Baoer Liu
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
| | - Rui Gao
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
| | - Liping Yang
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
| | - Wei Wei
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
| | - Jinsong He
- Department of Breast Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, P.R. China
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5
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Mejias A, Diez-Hermano S, Ganfornina MD, Gutierrez G, Sanchez D. Characterization of mammalian Lipocalin UTRs in silico: Predictions for their role in post-transcriptional regulation. PLoS One 2019; 14:e0213206. [PMID: 30840684 PMCID: PMC6402760 DOI: 10.1371/journal.pone.0213206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/15/2019] [Indexed: 01/20/2023] Open
Abstract
The Lipocalin family is a group of homologous proteins characterized by its big array of functional capabilities. As extracellular proteins, they can bind small hydrophobic ligands through a well-conserved β-barrel folding. Lipocalins evolutionary history sprawls across many different taxa and shows great divergence even within chordates. This variability is also found in their heterogeneous tissue expression pattern. Although a handful of promoter regions have been previously described, studies on UTR regulatory roles in Lipocalin gene expression are scarce. Here we report a comprehensive bioinformatic analysis showing that complex post-transcriptional regulation exists in Lipocalin genes, as suggested by the presence of alternative UTRs with substantial sequence conservation in mammals, alongside a high diversity of transcription start sites and alternative promoters. Strong selective pressure could have operated upon Lipocalins UTRs, leading to an enrichment in particular sequence motifs that limit the choice of secondary structures. Mapping these regulatory features to the expression pattern of early and late diverging Lipocalins suggests that UTRs represent an additional phylogenetic signal, which may help to uncover how functional pleiotropy originated within the Lipocalin family.
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Affiliation(s)
- Andres Mejias
- Departamento de Genetica, Universidad de Sevilla, Sevilla, Spain
| | - Sergio Diez-Hermano
- Instituto de Biologia y Genetica Molecular-Departamento de Bioquimica y Biologia Molecular y Fisiologia, Universidad de Valladolid-CSIC, Valladolid, Spain
- Departamento de Matemática Aplicada, Universidad Complutense, Madrid, Spain
| | - Maria D. Ganfornina
- Instituto de Biologia y Genetica Molecular-Departamento de Bioquimica y Biologia Molecular y Fisiologia, Universidad de Valladolid-CSIC, Valladolid, Spain
| | | | - Diego Sanchez
- Instituto de Biologia y Genetica Molecular-Departamento de Bioquimica y Biologia Molecular y Fisiologia, Universidad de Valladolid-CSIC, Valladolid, Spain
- * E-mail:
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6
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Gutiérrez AM, Montes A, Gutiérrez-Panizo C, Fuentes P, De La Cruz-Sánchez E. Gender influence on the salivary protein profile of finishing pigs. J Proteomics 2017; 178:107-113. [PMID: 29199151 DOI: 10.1016/j.jprot.2017.11.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 11/20/2017] [Accepted: 11/25/2017] [Indexed: 12/30/2022]
Abstract
A study on gender differences in the normal range of biomarkers in porcine saliva samples has the scope for further attention. In the present study, the salivary protein profiles of age-matched healthy male and female finishing pigs were compared. The levels of salivary adenosine deaminase (ADA) activity, haptoglobin (Hp) and C-reactive protein (CRP) have been quantified in 32 male and 32 female pigs to ensure the presence of gender effect on the median levels of salivary biomarkers. Moreover, the total salivary protein content was quantified and compared. The overall salivary protein distribution was compared with SDS-PAGE in 14 male and 14 female pigs and the possible gender influence in the salivary protein profile was analysed by 2DE in 6 male and 6 female pigs. Statistically significant differences were observed in the median values of Hp, CRP, and ADA between male and female pigs (p<0.005). Although the total salivary protein content was not different between the sexes, the salivary protein distribution and profile showed specific gender differences in three proteins of the lipocalin family: the odorant-binding protein, salivary lipocalin and lipocalin 1. These proteins have been related to animal immune status and should be further explored as possible porcine salivary biomarkers. SIGNIFICANCE The biological relevance of the reported research is based on the possible gender influence on the discovery of salivary biomarkers in porcine production. As differences have been reported in the salivary protein distribution in male pigs in comparison to that of female pigs, the normal-range values, according to gender, of the newly discovered biomarkers should be explored and defined prior to its application in the porcine production system. A hormonal sexual influence is highly hypothesized.
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Affiliation(s)
- Ana M Gutiérrez
- Department of Animal Medicine and Surgery, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain.
| | - Ana Montes
- Department of Animal Medicine and Surgery, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | - Cándido Gutiérrez-Panizo
- Department of Animal Medicine and Surgery, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | | | - Ernesto De La Cruz-Sánchez
- Department of Physical Activity and Sport, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, San Javier, Murcia, Spain
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7
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Nagnan-Le Meillour P, Vercoutter-Edouart AS, Hilliou F, Le Danvic C, Lévy F. Proteomic Analysis of Pig (Sus scrofa) Olfactory Soluble Proteome Reveals O-Linked-N-Acetylglucosaminylation of Secreted Odorant-Binding Proteins. Front Endocrinol (Lausanne) 2014; 5:202. [PMID: 25538681 PMCID: PMC4257092 DOI: 10.3389/fendo.2014.00202] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 11/13/2014] [Indexed: 11/13/2022] Open
Abstract
The diversity of olfactory binding proteins (OBPs) is a key point to understand their role in molecular olfaction. Since only few different sequences were characterized in each mammalian species, they have been considered as passive carriers of odors and pheromones. We have explored the soluble proteome of pig nasal mucus, taking benefit of the powerful tools of proteomics. Combining two-dimensional electrophoresis, mass spectrometry, and western-blot with specific antibodies, our analyses revealed for the first time that the pig nasal mucus is mainly composed of secreted OBP isoforms, some of them being potentially modified by O-GlcNAcylation. An ortholog gene of the glycosyltransferase responsible of the O-GlcNAc linking on extracellular proteins in Drosophila and Mouse (EOGT) was amplified from tissues of pigs of different ages and sex. The sequence was used in a phylogenetic analysis, which evidenced conservation of EOGT in insect and mammalian models studied in molecular olfaction. Extracellular O-GlcNAcylation of secreted OBPs could finely modulate their binding specificities to odors and pheromones. This constitutes a new mechanism for extracellular signaling by OBPs, suggesting that they act as the first step of odor discrimination.
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Affiliation(s)
- Patricia Nagnan-Le Meillour
- UMR 8576, USC-Unité de Glycobiologie Structurale et Fonctionnelle, INRA, CNRS, Université de Lille 1 , Villeneuve d'Ascq , France
| | | | - Frédérique Hilliou
- UMR 7254, UMR 1355 Institut Sophia Agrobiotech, INRA, CNRS, Université de Nice Sophia Antipolis , Sophia Antipolis , France
| | - Chrystelle Le Danvic
- Unité de Glycobiologie Structurale et Fonctionnelle, Union Nationale des Coopératives Agricoles d'Elevage et d'Insémination Animale (UNCEIA) , Villeneuve d'Ascq , France
| | - Frédéric Lévy
- UMR 7247, UMR 85 Unité de Physiologie de la Reproduction et des Comportements, INRA, CNRS, Université François Rabelais, Haras Nationaux , Nouzilly , France
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8
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Čepica S, Schröffel J, Redl B, Rohrer GA. Linkage mapping of twoTaqI PCR-RFLPs within intron 6 of the porcine gene (LCN1) encoding Tear lipocalin/von Ebner's gland protein. Anim Genet 2001. [DOI: 10.1046/j.1365-2052.1999.00498-7.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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9
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Čepica S, Yerle M, Stratil A, Schröffel J, Redl B. Regional localization of porcine myod1
, myf5
, lep
, ucp3
and LCN1
genes. Anim Genet 2001. [DOI: 10.1046/j.1365-2052.1999.00498-17.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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10
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Lichtlen P, Wang Y, Belser T, Georgiev O, Certa U, Sack R, Schaffner W. Target gene search for the metal-responsive transcription factor MTF-1. Nucleic Acids Res 2001; 29:1514-23. [PMID: 11266553 PMCID: PMC31279 DOI: 10.1093/nar/29.7.1514] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2000] [Revised: 02/07/2001] [Accepted: 02/07/2001] [Indexed: 11/13/2022] Open
Abstract
Activation of genes by heavy metals, notably zinc, cadmium and copper, depends on MTF-1, a unique zinc finger transcription factor conserved from insects to human. Knockout of MTF-1 in the mouse results in embryonic lethality due to liver decay, while knockout of its best characterized target genes, the stress-inducible metallothionein genes I and II, is viable, suggesting additional target genes of MTF-1. Here we report on a multi-pronged search for potential target genes of MTF-1, including microarray screening, SABRE selective amplification, a computer search for MREs (DNA-binding sites of MTF-1) and transfection of reporter genes driven by candidate gene promoters. Some new candidate target genes emerged, including those encoding alpha-fetoprotein, the liver-enriched transcription factor C/EBPalpha and tear lipocalin/von Ebner's gland protein, all of which have a role in toxicity/the cell stress response. In contrast, expression of other cell stress-associated genes, such as those for superoxide dismutases, thioredoxin and heat shock proteins, do not appear to be affected by loss of MTF-1. Our experiments have also exposed some problems with target gene searches. First, finding the optimal time window for detecting MTF-1 target genes in a lethal phenotype of rapid liver decay proved problematical: 12.5-day-old mouse embryos (stage E12.5) yielded hardly any differentially expressed genes, whereas at stage 13.0 reduced expression of secretory liver proteins probably reflected the onset of liver decay, i.e. a secondary effect. Likewise, up-regulation of some proliferation-associated genes may also just reflect responses to the concomitant loss of hepatocytes. Another sobering finding concerns gamma-glutamylcysteine synthetase(hc) (gamma-GCS(hc)), which controls synthesis of the antioxidant glutathione and which was previously suggested to be a target gene contributing to the lethal phenotype in MTF-1 knockout mice. gamma-GCS(hc) mRNA is reduced at the onset of liver decay but MTF-1 null mutant embryos manage to maintain a very high glutathione level until shortly before that stage, perhaps in an attempt to compensate for low expression of metallothioneins, which also have a role as antioxidants.
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Affiliation(s)
- P Lichtlen
- Institute of Molecular Biology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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11
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Salier JP. Chromosomal location, exon/intron organization and evolution of lipocalin genes. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1482:25-34. [PMID: 11058744 DOI: 10.1016/s0167-4838(00)00144-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lipocalins exhibit low sequence similarity that contrasts with a tightly conserved folding shared by all members of this superfamily. This conserved folding can be, at least partly, accounted for by a highly conserved gene structure. The array of lipocalin genes that have so far been studied mostly in mammals indicate a large conservation of a typical seven exon/six intron arrangement. Other conserved features include a partly coding exon 1 of variable size, fixed sizes of exons 2-5 that code for an array of lipocalin-specific beta-strands and a tendency of the last exons to either fuse or expand into further exons without major changes in the length of the resulting open reading frame. The conserved exon/intron arrangement as well as a clustering of most lipocalin genes in given chromosomes of human and mouse indicate that the lipocalin genes diverged from a shared ancestor by successive rounds of duplications followed by late changes in exon arrangements.
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Affiliation(s)
- J P Salier
- INSERM Unit-519 and Institut Fédératif de Recherches Multidisciplinaires sur les Peptides, Faculté de Médecine-Pharmacie, 22 Bvd Gambetta, 76183 Rouen Cedex, France.
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12
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Abstract
Human tear prealbumin, now called tear lipocalin, was originally described as a major protein of human tear fluid, which was thought to be tear specific. However, recent investigations demonstrated that it is identical with lingual von Ebner's gland protein, and is also produced in prostate, nasal mucosa and tracheal mucosa. Homologous proteins have been found in rat, pig and probably dog and horse. Tear lipocalin is an unusual lipocalin member, because of its high promiscuity for relative insoluble lipids and binding characteristics that differ from other members. In addition, it shows inhibitory activity on cysteine proteinases similar to cystatins, a feature unique among lipocalins. Although it acts as the principal lipid binding protein in tear fluid, a more general physiological function has to be proposed due to its wide distribution and properties. It would be ideally suited for scavenging of lipophilic, potentially harmful substances and thus might act as a general protection factor of epithelia.
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Affiliation(s)
- B Redl
- Institut für Mikrobiologie, Medizinische Fakultät, Universität Innsbruck, Fritz Pregl Strasse 3, A-6020 Innsbruck, Austria.
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