Abstract

Biobanking and Biorepositories

Rivka Ravid, Brain Bank Consultant, Royal Dutch Academy of Sciences

The use of proteomics on clinical and brain autopsy specimens, creates a unique discovery and validation platform for CNS Bio markers; additional use of MALDI mass spectrometry (MS) improves reproducibility, ease of validation, which in turn hinder translation into clinical practice. Hippocampal slices from Alzheimer's disease (AD) and controls, obtained at rapid autopsy, were used for the gene-centric statistics related to the gene expression. After separation of samples into soluble and membrane fractions, multi-dimensional LC separation technology was used and proteins were extracted into soluble and membrane fractions and then we applied OFFGEL fractionation. Collision induced dissociation (CID) and electron transfer dissociation (ETD) were used, followed by MS profiling (MALDI MS) combined with imaging technologies (MALDI MSI). A total of 7,418 proteins were off-gel fractionated and profiled; 471 proteins were determined to belong to Chromosome 11 and they are about 36 % of the proteins reported from the Global Proteome Machine Database. Quantitative analysis of gene expression was done on mRNA microarrays. Hippocampal proteomic analysis was integrated into the analysis for chromosome 11; Alpha crystallin B chain and apolipoprotein A-I were identified in all samples. Functional proteomics analysis in AD and PD will be further performed, targeting chromosome 11 proteins. The use of MALDI-MS +MALDI-MSI increases the concentration range and reproducibility of protein expression and correlates these with the available clinical data and trials. This is the key to future success of proteome biomarker validation and development.