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The term “biomarker” can be defined as any characteristic which can be objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, orpharmacological responses to a therapeutic intervention. Biomarkers can be highly diverse, and include specific molecules such as proteins (protein biomarkers), which can be used in screening tests for diagnosis. Proteomics consists of the large-scale characterization of all the expressed proteins in a cell, tissue or living organism at a specific moment and condition, using techniques such as two-dimensional electrophoresis (2-DE), mass-spectrometry (MS) and protein microarrays. During the last years, these high-throughput screening techniques have been extensively used for the discovery of multiple protein biomarkers, as they allow for the identification and quantification of a high number of proteins in a single sample and with high sensitivity. Alzheimer’s disease (AD) is a chronic, progressive and unremitting neurodegenerative disorder affecting fundamental brain areas for memory and cognition, mainly the neocortex and the hippocampus. It is the most common form of dementia worldwide, with an estimated prevalence between 10% and 30% in the aging population which is expected to double in the next years. Two main histopathological hallmarks define AD: extracellular amyloid β peptide (Aβ) deposits known as amyloid plaques, and intracellular aggregates of hyperphosphorylated tau known as neurofibrillary tangles (NFTs). Currently, the only useful biomarkers for AD diagnosis are based on cerebrospinal fluid (CSF) analysis and neuroimaging techniques, which restricts their use to specialty clinics. Therefore, AD diagnosis is mainly based on clinical symptoms, sometimes leading to misdiagnosis. Besides, this method fails to detect the disease at early stages. To counter these problems, new biomarkers useable in primary care settings, such as blood-based biomarkers, are needed in the field and are the focus of many research groups worldwide. Allergic diseases, also known as type I hypersensitivity disorders, constitute another group of chronic diseases whose prevalence has alarmingly increased in the population of developed countries. It is estimated that up to 25% of the population of these countries suffer from respiratory allergies such as rhinitis, conjunctivitis and asthma, which involve the production of high-affinity Immunoglobulin E (IgE) antibodies against generally harmless environmental antigens known as aeroallergens. While in tropical areas mites are the main cause of respiratory allergies, in North America and Europe pollen plays a major role in allergic sensitization (pollinosis). In Spain, olive (Olea europaea L.) pollen is the second leading cause of pollinosis after grass pollen, becoming the first one in regions like Andalusia, where olive is extensively cultivated. Besides, the continuous advertising of the Mediterranean diet has boosted olive cultivation in regions of the United States, Japan, China, South Africa and South America, where it will presumably become a main allergenic source. Although olive pollen allergens have been deeply characterized during the last years, some allergens potentially relevant for the diagnosis and management of this allergy have remained unidentified due to technical restrictions and limited genomics and proteomics data...

Alzheimer's disease (AD) is the most common form of dementia in developed countries. A better understanding of the events taking place at the molecular level would help to identify novel protein alterations, which might be used in diagnosis or for treatment development. In this study, we have performed the high-throughput analysis of 706 molecules mostly implicated in cell-cell communication and cell signaling processes by using two antibody microarray platforms. We screened three AD pathological groups -each one containing four pooled samples- from Braak stages IV, V and VI, and three control groups from two healthy subjects, five frontotemporal and two vascular dementia patients onto Panorama and L-Series antibody microarrays to identify AD-specific alterations not common to other dementias. Forty altered proteins between control and AD groups were detected, and validated by i) meta-analysis of mRNA alterations, ii) WB, and iii) FISH and IHC using an AD-specific tissue microarray containing 44 samples from AD patients at different Braak stages, and frontotemporal and vascular dementia patients and healthy individuals as controls. We identified altered proteins in AD not common to other dementias like the E3 ubiquitin-protein ligase TOPORS, Layilin and MICB, and validated the association to AD of the previously controverted proteins DDIT3 and the E3 ubiquitin-protein ligase XIAP. These altered proteins constitute interesting targets for further immunological analyses using sera, plasma and CSF to identify AD blood- or cerebrospinal fluid-biomarkers and to perform functional analysis to determine their specific role in AD, and their usefulness as potential therapeutic targets of intervention. This work was supported by the Ramón y Cajal funding grant, the SAF2014-53209-R and PI17CIII/00045 grants from the Ministerio de Economía y Competitividad and AESI, respectively, and the ILoveScience crowdfunding platform. R.B. was a fellow of the Ramón y Cajal program of the Ministerio de Economía y Competitividad (Spain). M.G.A. is supported by a contract of the Programa Operativo de Empleo Juvenil y la Iniciativa de Empleo Juvenil (YEI) with the participation of the Consejería de Educación, Juventud y Deporte de la Comunidad de Madrid y del Fondo Social Europeo. P.S.A. is supported by a FPU fellowship from the Spanish Ministry of Education, Culture and Sport. Sí