Biomarkers in Alzheimer's Disease Analysis by Mass Spectometry- Based Proteomics

Biomarkers in Alzheimer's Disease Analysis by Mass Spectometry- Based Proteomics

1. BIOMARKER: substance used as measurable indicator of a particular biological state (normal or pathologic)

   • IT SHOULD REFLECT: progression of disease providing better prognosis and early diagnosis
     • based on mass specrometry proteomics (whose goal is to identify and quantify proteins from biological samples)
       • SOURCES: human samples (fluids: blood, CSF, urine and saliva. DNA (and modifications), RNA, miRNA, proteins (PTM)
   • 3 PHASES IN THE DEVELOPMENT OF A NEW ONE
     • DISCOVERY PHASE: proteomic techniques are applied to blood or CSF to identify candidates
       • VERIFICATION PHASE: quantify the candidates to confirm differential expression in blood/CSF from cases vs controls
         • VALIDATION PHASE: considered for further clinical evaluation
           • MRM-MS and immunoassay
         • MRM-LC-MS/MS
       • LC-MS/MS with fractionation
   • TYPES
     • DNA- BASED
       • BLOOD- BASED:
         • CSF- BASED
           • PROTEINS: 0.15-0.45 g/L in plasma, proximal to the CNS (interacts with brain, reflects its biochemical changes), highly invasive, contáis components form the blood and CNS
             • MS, microarray, 2D gel
               • changes at protein levels are associated with AD
                 • basic biomarker: albumin (biomarker for blood brain barrier BBB)
                   • increase= BBB damage
                 • sPLA2 is a BBB factor
                   • increase= BBB damage
                 • Visinin-like 1 increased after stroke
                 • increase in tau/pTau= MCI to AD
                 • increase in neurofilament proteins= neuronal damage
                 • downgrade in FAB3, CHGA, B, Neurogranin
                 • elevated S-100B, GFAP
                 • related to Aβ
                   • BACE1, sAPPα/sAPPβ, or Aβ oligomers
         • PROTEINS: 60-80 g/L in plasma, blood is in contact with all cells, easily accesible (non-invasive), cost-time efficient, can be separated into components (plasma and serum)
           • MS, microarray, 2D gel
             • changes at protein levels are associated with AD
               • downregulated Aβ (plasma biomarker)
               • upregulated ApoE (chromosome 19)
               • IL-1α, IL-6 (increase risk)
               • Clusterin: ilipoprotein that is part of amyloid plaques
               • increased α-1-antichymotrypsin: inflammatory cascade and formation od amyloid fibrils
               • downregulated ADNP in early phase
       • DNA methylation studies. Obtained from cells and exosomes in plasma
       • miRNA: non-coding, players of postranscriptional gene modification
         • DETECTED BY: RT-PCR, microarray and sequencing, 2D gel
           • changes at miRNA levels are associated with AD
             • upregulation: miR-9,-125,-128, -34a, -145b, -155
             • downregulation: miR-107, -137, -181c, -9, -29b, -146a
   • PROTEOMIC TECNIQUES
     • they include several components: sample preparation, primary separation, protein or peptide identification and bioinformatic data analysis.
       • 2D GEL
       • LC-mass spectometry
       • clinical testing
       • radioimmunoassays
       • Western-blott
       • ELISA
       • MRM-Mass spectrometry

2. ALZHEIMER'S DISEASE (AD) develops slowly from 1) preclinical phase to 2) clinical syndrome

   • BIOMARKERS CURRENLY USED: primary (Aβ and tau)
   • possible biomarkers

3. TAREA 09 ARRIOLA VÁZQUEZ MARÍA JOSÉ, GARCÍA ECHEVERRIA GALA, JIMENEZ DELGADO ZOHE MUÑOZ-LEDO CERON PAULINA,