Orbitrap mass spectrometry for monitoring the ganglioside pattern in human cerebellum development and aging.

We have developed here a superior approach based on high-resolution (HR) mass spectrometry (MS) for monitoring the changes occurring with development and aging in the composition and structure of cerebellar gangliosidome. The experiments were focused on the comparative screening and structural analysis of gangliosides expressed in fetal and aged cerebellum by Orbitrap MS with nanoelectrospray ionization (nanoESI) in the negative ion mode. The employed ultrahigh-resolution MS platform allowed the discrimination, without the need of previous separation, of 159 ions corresponding to 120 distinct species in the native ganglioside mixtures from fetal and aged cerebellar biopsies, many more than detected before, when MS platforms of lower resolution were employed. A number of gangliosides, in particular polysialylated belonging to GT, GQ, GP, and GS classes, modified by O-fucosylation, O-acetylation, or CH3 COO- were discovered here, for the first time in human cerebellum. These components, found differently expressed in fetal and aged tissues, indicated that the ganglioside profile in cerebellum is development stage- and age-specific. Following the fragmentation analysis by high-energy collision-induced dissociation (HCD) tandem MS (MS/MS), we have also observed that the intimate structure of certain compounds has not changed during the development and aging of the brain, an aspect which could open new directions in the investigation of ganglioside biomarkers in cerebellar tissue.

Trends in Glycolipid Biomarker Discovery in Neurodegenerative Disorders by Mass Spectrometry.

Considering the devastating effects of neurodegenerative disorders and the increasing number of people affected by them, an early diagnosis even presymptomatic, prior to serious mental deterioration is necessary. Therefore, screening for biomarkers, especially glycolipids, in the biological matrices, either tissues or body fluids has proven to be of a great help in establishing an early diagnosis of the disease.The present chapter, divided into three parts, highlights the implementation and modern applications of the most avant-garde mass spectrometry (MS) techniques characterized by speed, sensitivity and data accuracy for de novo identification and monitoring of glycolipids with potential biomarker role. The first section reviews the etiology, epidemiology, clinical picture, as well as the current diagnostic methods for four of the most frequent neurodegenerative disorders: Parkinson's disease, Alzheimer's disease, Lewy body dementia and fronto-temporal dementia. The second section is dedicated to the role of glycolipids as biomarkers of these severe conditions. In the last part of the chapter, the state of the art in terms of mass spectrometry techniques for the detection of extremely valuable glycolipid biomarkers is described in detail. The proficiency of the MS, to be considered as and further developed into a routine method for early detection of neurodegenerative disorders, is also emphasized in the chapter.

Gangliosidome of human anencephaly: A high resolution multistage mass spectrometry study.

Widely dispersed throughout the entire body tissues, gangliosides (GGs) are essential components of neuronal cell membranes, where exhibit a vital role in neuronal function and brain development, directly influencing the neural tube formation, neurogenesis, neurotransmission, etc. Due to several factors, partial or complete closing faults of the fetal neural tube may occur in the first trimester of pregnancy, generating a series of neural tube defects (NTD), among which anencephaly. The absence in anencephaly of the forebrain and skull bones determines the exposure to the amniotic fluid of the remaining brain tissue and the spinal cord, causing the degeneration of the nervous system tissue. Based on the previously achieved information related to the direct alteration of neural development with deficient concentration of several GGs, a systematic and comparative mass spectrometry (MS) mapping assay on GGs originating from fetuses in different intrauterine developmental stages, i.e. the 29th (denoted An29), 35th (An35) and the 37th (An37) gestational weeks was here conducted. Our approach, based on Orbitrap MS under high sensitivity, resolution and mass accuracy conditions, enabled for the first time the nanoelectrospray ionization, detection and identification of over 150 glycoforms, mainly novel, polysialylated species. Such a pattern, specific for incipient developmental stages reliably documents the brain development stagnation, characteristic for anencephaly. Further, the fragmentation MS2-MS3 experiments by collision induced dissociation (CID) confirmed the incidence in all three samples of GT2(d18:1/16:2) as a potential biomarker. Therefore, this fingerprinting of the anencephalic gangliosidome may serve in development of approaches for routine screening and early diagnosis.