Overview of Lipid Mass Spectrometry and Lipidomics

Author(s):  
Simona Zarini ◽  
Robert M. Barkley ◽  
Miguel A. Gijón ◽  
Robert C. Murphy
Keyword(s):  
2020 ◽  
Author(s):  
Mathieu Tiquet ◽  
Raphaël La Rocca ◽  
Daan van Kruining ◽  
Pilar Martinez-Martinez ◽  
Gauthier Eppe ◽  
...  

<p><i>MALDI mass spectrometry imaging (MSI) is a powerful analytical method giving access to the 2D localizations of compounds in a thin section of a sample. To properly discern isobaric compounds in complex biological samples, dynamically harmonized ICR cell (ParaCell©) has been introduce to achieve extreme spectral resolution. However, high resolution MS images realized on a 9.4T FTICR High resolution instrument with recommended parameters suffered from an abnormal shifting of m/z ratios pixel to pixel. Resulting datasets show poor mass accuracy measurements and resolutions under estimations. By following the behavior of the Total Ion Current in function of the number of laser shots, the abnormal mass shifting phenomenon has been linked to the stability of the Total Ion Current (TIC) during images acquisitions. An optimization of laser parameters is proposed in order to limit the observed mass shift to retain machine specifications during MSI analyses. It is also shown that the method has been successfully employed to realize quality MS images with resolution above 1,000,000 in the lipid mass range across the whole image.</i></p>


2020 ◽  
Vol 55 (5) ◽  
pp. ii-ii
Author(s):  
Robert C. Murphy
Keyword(s):  

2020 ◽  
Vol 55 (5) ◽  
pp. e4492
Author(s):  
Robert C. Murphy
Keyword(s):  

2015 ◽  
Vol 112 (11) ◽  
pp. 3415-3420 ◽  
Author(s):  
Helena Khaliullina ◽  
Mesut Bilgin ◽  
Julio L. Sampaio ◽  
Andrej Shevchenko ◽  
Suzanne Eaton

Hedgehog ligands control tissue development and homeostasis by alleviating repression of Smoothened, a seven-pass transmembrane protein. The Hedgehog receptor, Patched, is thought to regulate the availability of small lipophilic Smoothened repressors whose identity is unknown. Lipoproteins contain lipids required to repress Smoothened signaling in vivo. Here, using biochemical fractionation and lipid mass spectrometry, we identify these repressors as endocannabinoids. Endocannabinoids circulate in human and Drosophila lipoproteins and act directly on Smoothened at physiological concentrations to repress signaling in Drosophila and mammalian assays. Phytocannabinoids are also potent Smo inhibitors. These findings link organismal metabolism to local Hedgehog signaling and suggest previously unsuspected mechanisms for the physiological activities of cannabinoids.


2020 ◽  
Vol 51 (5) ◽  
pp. 559-571
Author(s):  
Jihyeon Lim ◽  
Jennifer T. Aguilan ◽  
Rani S. Sellers ◽  
Fnu Nagajyothi ◽  
Louis M. Weiss ◽  
...  

Author(s):  
Mathieu Tiquet ◽  
Raphaël La Rocca ◽  
Daan van Kruining ◽  
Pilar Martinez-Martinez ◽  
Gauthier Eppe ◽  
...  

<p><i>MALDI mass spectrometry imaging (MSI) is a powerful analytical method giving access to the 2D localizations of compounds in a thin section of a sample. To properly discern isobaric compounds in complex biological samples, dynamically harmonized ICR cell (ParaCell©) has been introduce to achieve extreme spectral resolution. However, high resolution MS images realized on a 9.4T FTICR High resolution instrument with recommended parameters suffered from an abnormal shifting of m/z ratios pixel to pixel. Resulting datasets show poor mass accuracy measurements and resolutions under estimations. By following the behavior of the Total Ion Current in function of the number of laser shots, the abnormal mass shifting phenomenon has been linked to the stability of the Total Ion Current (TIC) during images acquisitions. An optimization of laser parameters is proposed in order to limit the observed mass shift to retain machine specifications during MSI analyses. It is also shown that the method has been successfully employed to realize quality MS images with resolution above 1,000,000 in the lipid mass range across the whole image.</i></p>


2013 ◽  
Author(s):  
Helena Khaliullina ◽  
Mesut Bilgin ◽  
Julio L. Sampaio ◽  
Andrej Shevchenko ◽  
Suzanne Eaton

Hedgehog proteins are lipid-modified secreted signaling molecules that regulate tissue development and homeostasis. Lipids contained in circulating lipoproteins repress the Hedgehog signaling pathway in the absence of Hedgehog ligand, but the identity of these lipids is unknown. Here, using biochemical fractionation and lipid mass spectrometry, we identify these inhibitory lipids as endocannabinoids. Endocannabinoids are present in lipoproteins of both flies and humans, and repress the pathway in both mammalian signaling assays and Drosophila wing imaginal discs. In Drosophila, endocannabinoids are required in vivo to keep the levels of Smoothened and full-length Cubitus interruptus (Ci155) low in the absence of Hedgehog. Furthermore, elevating their endogenous levels inhibits Hedgehog-dependent accumulation of Smoothened and Ci155. Interestingly, cannabis-derived phytocannabinoids are also potent pathway inhibitors in flies and mammals. These findings constitute a novel link between organismal metabolism and local Hedgehog signaling, and suggest previously unsuspected mechanisms for the broad physiological activities of cannabinoids.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Nathan Heath Patterson ◽  
Balqis Alabdulkarim ◽  
Anthoula Lazaris ◽  
Aurélien Thomas ◽  
Mieczyslaw M. Marcinkiewicz ◽  
...  

Author(s):  
Philippe Fragu

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.


Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.


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