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PROTEOMICS OF OBESITY Part II Prof. Dr. E.C.M. Mariman. Contents Slides Proteomics of obesity and adipose tissue: overview 1 -11 Protein profiling methodologies 12 – 23 Protein secretion by adipocytes 24 – 47 Molecular mechanisms for obesity-related physiology 48 – 59
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PROTEOMICS OF OBESITY Part II Prof. Dr. E.C.M. Mariman
Contents Slides Proteomics of obesity and adipose tissue: overview 1 -11 Protein profiling methodologies 12 – 23 Protein secretion by adipocytes 24 – 47 Molecular mechanisms for obesity-related physiology 48 – 59 Proteomics in obesity: summary 60 Some literature references 61 Abbreviations used 62
BMI > 30 kg/m2 25 kg/m2 < BMI > 30 kg/m2 Obesity in The Netherlands weight length BMI = 2 Overgewicht = overweight Ernstig overgewicht = obese
Obesity linked with diseases Reduced fertility Obesity Diabetes cardiovascular diseases Cancer
ADIPOSE TISSUE: adipocytes / stromal cells
GENE-EXPRESSION PROFILING mouse 3T3-L1 (pre)adipocytes
RNA PROTEIN METABOLITE GENE GENETICS PROTEOMICS METABOLOMICS TRANSCRIPTOMICS
WHAT TYPE OF INFORMATION? ASPECTS OF PROTEIN FUNCTION • Protein identification • Protein quantification • Protein turnover • Posttranslational modifications • Protein interactions and complex formation • Cellular localization and translocation • Structural analysis
Methodologies • Advanced: • - Multi-dimensional LC-MS • - Imaging MS • - SPR-BIA • - BIA-MS • - Chemical protein • synthesis • - Antibody/protein arrays • Chip-based • microprocessing • - Crystallography • - NMR • Protein modeling • Tandem MS • FT-MS Moderately advanced: - HPLC - LC-MS • MALDI-TOF MS • Peptide fingerprinting - SELDI-TOF MS - ICAT - MIDA - Edman degradation • (Recombinant) protein production - Yeast two-hybrid system - Phage display Standard: - Cell fractionation - Affinity chromatography - 1D and 2D gel electrophoresis - Western blotting - ELISA - Immunocytochemistry
Proteomics, why? • “ Gene structure alone tells us very little about the physiological • function of proteins since it ignores the co- and post- • translational modifications to which they are subjected.” • (Edmund Fisher, 1997, Nobel Laureate Physiology & Medicine 1992) • Proteins are the “working horses” in the cell • Proteins are still preferred targets for drug- and nutritional • intervention • Body fluids contain proteins and usually not RNA
PROTEINS Cy3Cy5 MIX INCUBATE
ANTIBODY ARRAY PROTEINS Cy3Cy5 MIX INCUBATE
extract proteins separate them determine relative quantity identify differential proteins changed genes/pathways Techniques 2D –gel electrophoresis staining mass spectrometry pathway analysis
Iso-electric focussing Protein profiling: impression of identity and quantity Mass separation
PROTEIN (GENE)-IDENTIFICATION PROTEIN FRAGMENTS FINGERPRINT M/Z Bouwman et al., Rapid Comm Mass Spectrom 2005
MALDI-TOF MASS SPECTROMETRY + - flight tube laser detector proteins/peptides + matrix M/Z
Protein-identification via fingerprinting PROTEIN FRAGMENTS FINGERPRINT M/Z TRYPTIC PEPTIDES PROTEIN DATABASE HUGO M/Z
PROTEINS MEMBRANE STRUCTURAL CYTOSOLIC 2D-GELS 2D-LC
ADIPOCYTE FUNCTIONING IN OBESITY Protein secretion by adipocytes
Obesity at cellular level THE SECRETOME
Excretion products from adipocytes Cardio-vascular effects Insulin signaling ApoE TNF- Angiotensinogen Resistin Plasminogen activator inhibitor-1 (PAI-1) Adiponectin Weight regulation Vasc. endoth. growth factor (VEGF) Leptin IL-6 Pro-inflamm. cytokines Retinol-binding protein IL-8 Phospholipid transfer protein Hepatocyte growth factor Lipoprotein lipase (LPL) Insulin-like growth factor-1 (IGF-1) Cholesteryl ester transfer protein Lipid handling Growth factors Others Bradley et al. Recent Prog Horm Res. 2001;56:329-58
Research approach: secretome profiling Model system: mouse 3T3-L1 (pre-)adipocytes Excreted proteins Fat storage
Inhibition of protein excretion from 3T3-L1 cells Day 12 37°C 37°C + BFA 20°C
41 different proteins as candidates of secreted proteins related with adipocyte differentiation Excreted proteins during 3T3-L1 differentiation subtotal identified spots 161 unknown spots 32 total 193
EXCRETED PROTEINS Newly identified: Macrophage migration inhibitory factor - infiltration Pigment epithelium derived factor - vascularisation Prohibitin - cell growth and differentiation Collagens and modifiers: Type I, III, IV, V, VI Matrix metalloproteinase 2 Procollagen C-proteinase enhancer protein Protein-lysine 6-oxidase
EXCRETED PROTEINS Newly identified: Macrophage migration inhibitory factor - infiltration Pigment epithelium derived factor - vascularisation Prohibitin - cell growth and differentiation Collagens and modifiers: Type I, III, IV, V, VI Matrix metalloproteinase 2 Procollagen C-proteinase enhancer protein Protein-lysine 6-oxidase
Novel adipokine in human plasmaPigment epithelium-derived factor(PEDF) r = 0.583
EXCRETED PROTEINS Newly identified: Macrophage migration inhibitory factor - infiltration Pigment epithelium derived factor - vascularisation Prohibitin - cell growth and differentiation Collagens and modifiers: Type I, III, IV, V, VI Matrix metalloproteinase 2 Procollagen C-proteinase enhancer protein Protein-lysine 6-oxidase
THERAPY KILLER PEPTIDE ADIPOCYTE VASCULAR EPITHELIUM PROHIBITIN Kolonin et al., Nat. Med. 2004
EXCRETED PROTEINS Newly identified: Macrophage migration inhibitory factor - infiltration Pigment epithelium derived factor - vascularisation Prohibitin - cell growth and differentiation Collagens and modifiers: Type I, III, IV, V, VI Matrix metalloproteinase 2 Procollagen C-proteinase enhancer protein Protein-lysine 6-oxidase
Collagen synthesis by Preadipose and Non-Preadipose 3T3 cells • HyPro (%) Collagen / synthesized Formation of Adipose • total cell protein (%) cells in resting • 3T3-M2 5.5 1.9 virtually none • 3T3-L1 9.6 3.2 abundant • 9.9 3.3 Green & Meuth, Cell 3:127-133,1974
BASAL LAMINA COLLAGEN IV STAINING Pierleoni et al., Eur, J. Histochem. 1998
Modulation of the secretion of adipocytes Characterize: 2 days treatment with - glucose - insulin 1. culture medium proteins 2. cellular total RNA 1. medium proteins: 2D and 1D gel analysis 2. mRNA: RT-PCR and microarray analysis
high insulin basal high glucose high insulin + glucose collagen I alpha1 C-peptide collagen III alpha1 C-peptide collagen I alpha 2 C-peptide Major effect on 2D gel
Microarray analysis Cy5 sample Cy3 reference extra set : genes encoding mitochondrial proteins and secretory proteins MWG mouse 10 K array with extra gene sets 50-mer mouse non-redundant oligos: 10060 in house printed
Comparison on transcriptome and proteome of secretory genes
Collagen post-translational modifications Alberts et al. Molecular Biology of The Cell. 3rd
Collagen processing enzymes – Ins – Ins + Ins + Ins
from a proteomics viewpoint, insulin has a significant impact on protein secretion of 3T3-L1 adipocytes • transcription is not the major regulation point for these secreted proteins • the discrepancy of the insulin effect between transcript and secretion level of collagens, may be partly explained by the transcriptional regulation of processing enzymes. Wang et al., Diabetologia 2006
SECRETOME: SECRETED INTERVENTION PROTEINS TARGETS ECM COMPONENTS INSULIN-REGULATED
MOLECULAR MECHANISMS FOR OBESITY-RELATED PHYSIOLOGY EC Framework Programme 5 project NUGENOB : Low Fat-Burners vs High Fat-Burners
Whole body nutrient oxidation: carbohydrates fatty acids LFO > HFO Different fatty acid flux visible in adipose proteome?
LFO HFO • Encountered problems: • Quality of the tissue (biopsy) • Contamination (blood) • Normalization 2D-differential proteins: plasma and blood cell derived
VASCULARISATION 50 µm 50 µm Water-Soluble Quantum Dots for Multiphoton Fluorescence Imaging in VivoLarson DR et al. 2003 Science 300 ( 5624) ,1434-1436