scholarly journals Rapid Alterations in Cerebral White Matter Lipid Profiles After Ischemic-Reperfusion Brain Injury in Fetal Sheep as Demonstrated by MALDI-Mass Spectrometry

2019 ◽  
Vol 22 (4) ◽  
pp. 344-355 ◽  
Author(s):  
Gina M Gallucci ◽  
Ming Tong ◽  
Xiaodi Chen ◽  
Barbara S Stonestreet ◽  
Amy Lin ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
White Matter ◽  
Lipid Composition ◽  
Lipid Profiles ◽  
Maldi Ms ◽  
Cerebral White Matter ◽  
Ionization Mass ◽  
Myelin Lipid ◽  
Fetal Sheep ◽  
Bilateral Carotid

Background Perinatal ischemia-reperfusion (I/R) injury of cerebral white matter causes long-term cognitive and motor disabilities in children. I/R damages or kills highly metabolic immature oligodendroglia via oxidative stress, excitotoxicity, inflammation, and mitochondrial dysfunction, impairing their capacity to generate and maintain mature myelin. However, the consequences of I/R on myelin lipid composition have not been characterized. Objective This study utilized matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to assess alterations in cerebral supraventricular white matter myelin lipid profiles in a fetal sheep model of perinatal I/R. Methods Fetal sheep (127 days gestation) were studied after 30 minutes of bilateral carotid artery occlusion followed by 4 (n = 5), 24 (n = 7), 48 (n = 3), or 72 (n = 5) hours of reperfusion, or sham treatment (n = 5). White matter lipids were analyzed by negative ion mode MALDI-MS. Results Striking I/R-associated shifts in phospholipid and sphingolipid expression occurred over the 72-hour time course with most responses detected within 4 hours of reperfusion and progressing at the 48- and 72-hour points. I/R decreased expression of phosphatidic acid and phosphatidylethanol amine and increased phosphatidylinositol, sulfatide, and lactosylceramide. Conclusions Cerebral I/R in mid-gestation fetal sheep causes rapid shifts in white matter myelin lipid composition that may reflect injury, proliferation, or recovery of immature oligodendroglia.

scholarly journals Critical Shifts in Cerebral White Matter Lipid Profiles After Ischemic–Reperfusion Brain Injury in Fetal Sheep as Demonstrated by the Positive Ion Mode MALDI-Mass Spectrometry

Cell Medicine ◽  
2020 ◽  
Vol 12 ◽  
pp. 215517901989700
Author(s):  
Suzanne M. de la Monte ◽  
Gina M. Gallucci ◽  
Amy Lin ◽  
Ming Tong ◽  
Xiaodi Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
White Matter ◽  
Lipid Profiles ◽  
White Matter Injury ◽  
Cerebral White Matter ◽  
Neuronal Membrane ◽  
Ionization Mass ◽  
Fetal Sheep ◽  
Ischemic Reperfusion ◽  
Bilateral Carotid

Ischemic–reperfusion (I/R) injury to cerebral white matter during the perinatal period leads to long-term cognitive and motor disabilities in children. Immature white matter oligodendrocytes are especially vulnerable to metabolic insults such as those caused by hypoxic, ischemic, and reperfusion injury. Consequences include an impaired capacity of oligodendrocytes to generate and maintain mature lipid-rich myelin needed for efficient neuronal conductivity. Further research is needed to increase an understanding of the early, possibly reversible myelin-associated pathologies that accompany I/R white matter injury. This experiment characterized I/R time-dependent alterations in cerebral white matter lipid profiles in an established fetal sheep model. Fetal sheep (127 days gestation) were subjected to 30 min of bilateral carotid artery occlusion followed by 4 h ( n = 5), 24 h ( n = 7), 48 h ( n = 3), or 72 h ( n = 5) of reperfusion, or sham treatment ( n = 5). Supraventricular cerebral white matter lipids were analyzed using the positive ionization mode matrix-assisted laser desorption/ionization mass spectrometry. Striking I/R-associated shifts in phospholipid (PL) and sphingolipid expression with a prominent upregulation of cardiolipin, phosphatidylcholine, phosphatidylinositol monomannoside, sphingomyelin, sulfatide, and ambiguous or unidentified lipids were observed to occur mainly at I/R-48 and normalized or suppressed responses at I/R-72. In fetal sheep, cerebral I/R caused major shifts in white matter myelin lipid composition favoring the upregulated expression of diverse PLs and sphingolipids which are needed to support neuronal membrane, synaptic, metabolic, and cell signaling functions.

scholarly journals Identification of key molecular biomarkers involved in reactive and neurodegenerative processes present in inherited congenital hydrocephalus

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Betsaida Ojeda-Pérez ◽  
José A. Campos-Sandoval ◽  
María García-Bonilla ◽  
Casimiro Cárdenas-García ◽  
Patricia Páez-González ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
White Matter ◽  
Mouse Model ◽  
Grey Matter ◽  
Lipid Analysis ◽  
Congenital Hydrocephalus ◽  
Cerebral White Matter ◽  
Periventricular White Matter ◽  
Ionization Mass ◽  
Oligodendrocyte Differentiation

Abstract Background Periventricular extracellular oedema, myelin damage, inflammation, and glial reactions are common neuropathological events that occur in the brain in congenital hydrocephalus. The periventricular white matter is the most affected region. The present study aimed to identify altered molecular and cellular biomarkers in the neocortex that can function as potential therapeutic targets to both treat and evaluate recovery from these neurodegenerative conditions. The hyh mouse model of hereditary hydrocephalus was used for this purpose. Methods The hyh mouse model of hereditary hydrocephalus (hydrocephalus with hop gait) and control littermates without hydrocephalus were used in the present work. In tissue sections, the ionic content was investigated using energy dispersive X-ray spectroscopy scanning electron microscopy (EDS-SEM). For the lipid analysis, matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) was performed in frozen sections. The expression of proteins in the cerebral white matter was analysed by mass spectrometry. The oligodendrocyte progenitor cells (OPCs) were studied with immunofluorescence in cerebral sections and whole-mount preparations of the ventricle walls. Results High sodium and chloride concentrations were found indicating oedema conditions in both the periventricular white matter and extending towards the grey matter. Lipid analysis revealed lower levels of two phosphatidylinositol molecular species in the grey matter, indicating that neural functions were altered in the hydrocephalic mice. In addition, the expression of proteins in the cerebral white matter revealed evident deregulation of the processes of oligodendrocyte differentiation and myelination. Because of the changes in oligodendrocyte differentiation in the white matter, OPCs were also studied. In hydrocephalic mice, OPCs were found to be reactive, overexpressing the NG2 antigen but not giving rise to an increase in mature oligodendrocytes. The higher levels of the NG2 antigen, diacylglycerophosphoserine and possibly transthyretin in the cerebrum of hydrocephalic hyh mice could indicate cell reactions that may have been triggered by inflammation, neurocytotoxic conditions, and ischaemia. Conclusion Our results identify possible biomarkers of hydrocephalus in the cerebral grey and white matter. In the white matter, OPCs could be reacting to acquire a neuroprotective role or as a delay in the oligodendrocyte maturation.

scholarly journals MALDIViz: A Comprehensive Informatics Tool for MALDI-MS Data Visualization and Analysis

2017 ◽  
Vol 22 (10) ◽  
pp. 1246-1252 ◽  
Author(s):  
Kishore Kumar Jagadeesan ◽  
Simon Ekström
Keyword(s):  
Mass Spectrometry ◽  
High Throughput ◽  
High Throughput Screening ◽  
Web Application ◽  
Low Cost ◽  
Maldi Ms ◽  
Ionization Mass ◽  
Label Free ◽  
Label Free Detection ◽  
R Shiny

Recently, mass spectrometry (MS) has emerged as an important tool for high-throughput screening (HTS) providing a direct and label-free detection method, complementing traditional fluorescent and colorimetric methodologies. Among the various MS techniques used for HTS, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides many of the characteristics required for high-throughput analyses, such as low cost, speed, and automation. However, visualization and analysis of the large datasets generated by HTS MALDI-MS can pose significant challenges, especially for multiparametric experiments. The datasets can be generated fast, and the complexity of the experimental data (e.g., screening many different sorbent phases, the sorbent mass, and the load, wash, and elution conditions) makes manual data analysis difficult. To address these challenges, a comprehensive informatics tool called MALDIViz was developed. This tool is an R-Shiny-based web application, accessible independently of the operating system and without the need to install any program locally. It has been designed to facilitate easy analysis and visualization of MALDI-MS datasets, comparison of multiplex experiments, and export of the analysis results to high-quality images.

scholarly journals Cerebral Blood Flow Heterogeneity in Preterm Sheep: Lack of Physiologic Support for Vascular Boundary Zones in Fetal Cerebral White Matter

2007 ◽  
Vol 28 (5) ◽  
pp. 995-1008 ◽  
Author(s):  
Melissa M McClure ◽  
Art Riddle ◽  
Mario Manese ◽  
Ning Ling Luo ◽  
Dawn A Rorvik ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Ischemia Reperfusion ◽  
Three Dimensional ◽  
Cerebral White Matter ◽  
Periventricular White Matter ◽  
Fetal Sheep ◽  
Border Zones ◽  
Neurologic Disability

Periventricular white matter (PVWM) injury is the leading cause of neurologic disability in survivors of prematurity. To address the role of ischemia in PVWM and cerebral cortical injury, we hypothesized that immaturity of spatially distal vascular ‘end zones’ or ‘border zones’ predisposes PVWM to greater decreases in cerebral blood flow (CBF) than more proximal structures. We quantified regional CBF with fluorescently labeled microspheres in 0.65 gestation fetal sheep in histopathologically defined three-dimensional regions by post hoc digital dissection and coregistration algorithms. Basal flow in PVWM was significantly lower than in gyral white matter and cortex, but was equivalent in superficial, middle, and deep PVWM. Absolute and relative CBF (expressed as percentage of basal) did not differ significantly during ischemia or reperfusion between PVWM, gyral white matter, or cortex. Moreover, CBF during ischemia-reperfusion was equivalent in three adjacent PVWM levels and was not consistent with the magnitude of severity of PVWM injury, defined by TUNEL (terminal deoxynucleotidyltransferase-mediated dUPT nick end labeling) staining. However, the magnitude of ischemia was predicted by the severity of discrete cortical lesions. Hence, unlike cerebral cortex, unique CBF disturbances did not account for the distribution of PVWM injury. Previously defined cellular maturational factors, thus, appear to have a greater influence on PVWM vulnerability to ischemic injury than the presence of immature vascular boundary zones.

265 MATRIX-ASSISTED LASER DESORPTION IONIZATION MASS SPECTROMETRY (MALDI-MS) CHARACTERIZATION OF SPERM LIPID PROFILES OF BULLS WITH DIFFERENT CAPACITIES OF EMBRYO IN VITRO PRODUCTION

2010 ◽  
Vol 22 (1) ◽  
pp. 289
Author(s):  
C. R Ferreira ◽  
J. C. Borges ◽  
L. F. A. Santos ◽  
F. C. Gozzo ◽  
P. H. Franscechini ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Lipid Profiles ◽  
Maldi Ms ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
In Vitro Production ◽  
Vitro Production ◽  
Matrix Assisted Laser

Matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS) has been applied to study sperm lipid profiles. Lipids are known to play a crucial role in sperm membrane physico-chemical behavior during cryopreservation. In this work, we show the results of characterization of sperm lipid profiles from 2 bulls with different capacities of in vitro embryo production by MALDI-MS direct analysis. The bull capacities judged by the rate of blastocyst formation after IVP with semen from seven different ejaculates per each animal were 19.1 and 35.3% for bulls 1 and 2, respectively (P < 0.05). For MALDI-MS analysis, frozen semen from each ejaculate was thawed in water at 25°C for 40 s. Sperm was washed 3 times by centrifugatin in 1 mL of PBS at 3000 × g for 10 min. Samples were stored at -20°C in 200 μL of methanol:PBS (vol/vol) solution until analysis. A Synapt HDMS mass spectrometer (Waters Corp., Milford, MA, USA) equipped with a MALDI was used. All spectra were collected for 45 s in the positive ion mode at the mass range of m/z 450 to 1200. The volume of 1 μL of the semen pellet was spotted in the target plate and allowed to dry. Afterward, 1 μL of 2,5-dihydroxybenzoic acid (DHB) was added as matrix. The 50 most intense monoisotopic ions were considered for principal component analysis (PCA). Values of m/z and relative ion intensities were processed using the software Pirouette v.3.11 (Infometrix, Woodinville, WA, USA). Direct MALDI-MS analysis of bulls 1 and 2 spermatozoa with no extraction provided informative spectra containing either [M + Na]+ or [M + H]+ ions characteristic of sphingomyelins, such as m/z 753.6 for SM 18:0, phosphocholines (m/z 780.6 for PC 34 : 2; 782.6 for PC 34 : 1; 806.6 for PC 36 : 6; 808.6 for 36 :2; 828.6 for PC38 : 6; and 830.6 for PC38 : 5), plasmalogens (m/z 790.6 for 1-palmitenyl-2-docosahexanoyl-GPC and 814.6 for 1-palmityl-2-docosaheaenoyl-GPC); and triacylglycerols (m/z 881.7 for sn-glycerol-palmitoleate-oleate-oleate). PCA showed clear separation between bulls 1 and 2 ejaculates, indicating that each bull presented a characteristic and reproducible (from different ejaculates) profiles. Differences in the relative intensities of the ions mentioned above contributed for bulls 1 and 2 differentiation by PCA. PC1 and PC2 explained 86.5% of the data variance. In conclusion, a fast sample preparation protocol followed by MALDI-MS appears to provide characteristic lipid fingerprints for crude spermatozoa (ejaculates) of bulls with different capacities of embryo in vitro production. Experiments involving a larger and more statically relevant set of samples are underway. We thank the Brazilian research foundations FAPESP (2008/10756-7) and CNPq.

Identification of a Crystalline Drug Metabolite in Tissue Sections using Microscopy and Maldi-MS

2000 ◽  
Vol 6 (S2) ◽  
pp. 1002-1003
Author(s):  
J. Fagerland ◽  
L. Miesbauer ◽  
R. Burton ◽  
F. Seiler ◽  
J. Neilly ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Metabolic Pathways ◽  
Renal Toxicity ◽  
Polarized Light ◽  
Parent Drug ◽  
Maldi Ms ◽  
Drug Candidate ◽  
Ionization Mass ◽  
X Ray ◽  
Tissue Sections

Development of a potential drug candidate was discontinued when rats treated with the compound developed severe renal toxicity after one week of daily dosing. Tubular degeneration in the kidney was accompanied by deposition of large amounts of crystalline material, which was also present in spleen and pancreas (Fig. 1). It was presumed that the crystals were precipitated parent drug or one of its metabolites. Using microscopy and mass spectrometry, it was confirmed that the crystals were indeed derived from the drug and not endogenously formed; in addition, the precise metabolite that had precipitated in the tissues was identified, providing clues to the metabolic pathways involved.Frozen sections of phosphate-buffered formaldehyde-fixed kidney, pancreas, and spleen were evaluated by polarized light microscopy (PLM), scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDXS), and matrix assisted laser desorption ionization-mass spectrometry (MALDI-MS). For reference, crystals of the trifluoroacetate salt of the parent drug were also analyzed using these methods.

scholarly journals Application of dyes as doping agents in MALDI-MS matrices for the signal enhancement of proteins

RSC Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 6598-6604
Author(s):  
Arslan Ali ◽  
Najia Shahid ◽  
Syed Ghulam Musharraf
Keyword(s):  
Mass Spectrometry ◽  
Laser Desorption ◽  
Maldi Ms ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
As Doping ◽  
Desorption Ionization ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Dyes can significantly influence the ionization of proteins, when used as dopants in conventional matrices used for Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS).

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