01 / 79High throughput urine biomarker discovery and integrative analysis for translational medicine
1 / 17
Télécharger la présentation
High throughput urine biomarker discovery and integrative analysis for translational medicine
Une image / un lien ci-dessous est fourni (tel quel) pour télécharger la présentation
Politique de téléchargement : le contenu du site vous est fourni TEL QUEL pour votre information et votre usage personnel ; il ne peut être vendu, concédé sous licence ni partagé sur d’autres sites sans l’accord de son auteur.Le contenu vous est fourni TEL QUEL, pour votre information et votre usage personnel uniquement.Téléchargez la présentation en cliquant sur ce lien.Lors du téléchargement, si vous ne parvenez pas à télécharger une présentation, l’éditeur a peut-être supprimé le fichier de son serveur.Pendant le téléchargement, si vous ne parvenez pas à obtenir une présentation, le fichier a peut-être été supprimé par l’éditeur.
Biomarker A molecular indicator of a specific biological property; a biochemical feature or facet that can be used to measure the progress of disease or the effects of treatment (NIH, 2002)
Where to look for biomarkers • Disease tissue • Proximal/distal fluids • Plasma/serum, urine, amniotic, synovial fluid, CSF, saliva, tears, etc.
Why Urine? • Patient consenting • Non-invasive • Easy to collect for time course analysis • Abundant and stable
Urine is a rich resource for biomarker discovery • Filtration of plasma • 900 liters daily • Urine proteome • > 1500 proteins, ~30 mg/day • 30% from circulation • 70% from urogenital tract • Urine peptidome • > 100, 000 naturally occurring peptide, ~20 mg/day
Urine Peptidome: a fertile ground for biomarker discovery • Equal mass of protein and peptide in urine translates into at least a ten-fold greater molar abundance of peptides than proteins • Urine peptide analysis is not hampered by highly abundant protein issues • One hour one dimensional HPLC separation is sufficient for the analysis of greater than 100,000 urine peptides, allowing a high throughput biomarker discovery
Challenges of Urine Analysis • Dilution factor causing concentration variations • Solution: content normalization • Creatinine; house keeping urine abundant peptides; equal peptide mass • Peptide content can be complicated by • Diet, exercise, circadian rhythm, circulatory levels of hormones • Solution: careful experimental design to avoid these confounding issues, e.g., • Cohorts of patients of similar demographics • Multi-center sample collection and validation
Biomarker HTS Flows Sample peptides: -Class 1:1,2,3… -Class 2:1,2,3… -Class 3:1,2,3… MASS-Conductor ® Machine learning feature discovery and classification RP-HPLC Collect 120 fractions on MALDI plates MALDI-TOF MS on each fraction Candidate Biomarkers 987.62 1027.51 1098.55 etc.
Biomarker Confirmation/Validation Protein ID MS/MS Testing Validation New Center sample sets New sample Sets Identify Differentiating Markers Quantitative MS Higher throughput Quantitative methods Exploration Immunoassay New Longitudinal sample sets
Data Challenges in Urine Peptide Biomarker Discovery • Data tracking and storage • Patient demographics • Peptide profiles in various fractions/samples • Dimension reduction and data reduction • Multi-dimensional data sets • Huge data sets and lots of noise A project of 40 samples produced 241.5 GB raw data in MYSQL database Peptide mass Patient ID HPLC fraction Patient demographics Peptide signal
Decode the Urine Peptidome • Peak finding in each fraction for each sample • Align the peaks across the samples • Create common peak index
Data mining issues in Biomarker Discovery • Peak number >> sample number • False discovery in multiple hypothesis testing • Multi-class classification and validation • Discovery of biomarker signature
MASS-Conductor® Platform Support Urine Peptide Biomarker Discovery • Robustly loading and tracking of high volume proteomic data • Robust reduction of raw data sets and enabling of efficient and accurate peak finding, alignment and indexing • Robust and automatic high throughput computing for expensive algorithms • Integration of FDR analysis and multi-class classification algorithms to obtain statistically differentiating feature panels • Automatic generation of data reports with graphics
Kidney Transplant Rejection • Most effective treatment for end stage renal disease • 16,000 per year in US • Grafts monitored by biopsy • Unmet needs: • Less invasive and more frequent monitoring • Acute rejection vs. stable graft • Acute rejection vs. BK virus
Allograft Acute Rejection Urine Biomarker Discovery 1 2 3 4 LCMS Data reduction Supervised Data mining Unsupervised Data mining Quantitative LCMS Feature selection Training Testing 2D - Clustering Validation Peak finding Peak alignment Peak indexing
Hypothesis: Collagen Breakdown and Deposition in AR Integrated Analysis Increased TIMP1 (Collagenase Inhibitor) in AR Decreased Collagenase Activity In AR tissue Urine Peptidomics Biopsy Gene Expression GSE 14328 Increased MMP7 in AR Urine Decreased Collagen Peptides In AR Decreased Collagen Breakdown in AR Renal Biopsy Increased Collagen Deposition in AR Increased Collagen Expression in AR Urine Peptide Analysis by MS More Graft Fibrosis After an AR episode?
Unmet Medical Needs in Necrotizing Entrocolitis Necrotizing enterocolitis (NEC) is a medical condition primarily seen in premature infants, where portions of the bowel undergo necrosis (tissue death). Despite decades of research the pathogenesis of NEC remains obscure, the diagnostic parameters unclear, and both treatment and prevention strategies remain inadequate and dated. There is the real need for better molecular identification of NEC in order to assist in altering its onset and progression.
Clinical Parameters Based Model stratifies Necrotizing Enterocolitis Patients NEC M S 30 Low Risk Group Intermediate Risk Group Rate of NEC-S occurrence (% patients) 20 M: n = 16 S: n = 10 M: n = 26 S: n = 0 High Risk Group 10 M: n = 2 S: n = 15 0 -10 0 10 20 30 40 NEC score
Proposed Ensemble Approach to Diagnose Necrotizing Enterocolitis Patients Discovery set n = 34 NEC Patients NEC M S Clinical Diagnosis 17 17 Medical NEC Scoring Clinical Model NEC Risk Groups Low n=7 Intermediate n=15 High n=9 N/A n=3 Clinical Diagnosis M S M S M S 7 0 9 6 0 9 NEC Risk Diagnosed as M 7 0 4 3 0 1 Diagnosed as S 0 0 5 3 0 8 Urine peptide based Classification Urine Biomarkers Classified as M 7 0 8 1 0 0 Classified as S 0 0 1 5 0 9 Percent Agreement with clinical diagnosis 100 % 100 % 88.9 % 83.3 % 100 % 100 % + - + - + - NEC Diagnosis 100 % 86.1 % 100 % P = 0.01
Urine peptide biomarkers: the discovery process Biomarker panels Sample peptides: -Class 1:1,2,3… -Class 2:1,2,3… -Class 3:1,2,3… MASS-Conductor ® Machine learning feature discovery and classification SCX/RP-HPLC Collect 100 fractions on MALDI plates MALDI-TOF MS for each sample LC fraction -- m/.z --abundance Prospective validation with quantitative mass spec (MRM) MSMS protein ID
Connexion au compte
Connectez-vous pour publier votre contenu sur SlideServe.