Discovery of novel neutral glycosphingolipids in cereal crops: rapid profiling using reversed-phased HPLC-ESI-QqTOF with parallel reaction monitoring.

This study explores the sphingolipid class of oligohexosylceramides (OHCs), a rarely studied group, in barley (Hordeum vulgare L.) through a new lipidomics approach. Profiling identified 45 OHCs in barley (Hordeum vulgare L.

The Effect of Cold Stress on the Root-Specific Lipidome of Two Wheat Varieties with Contrasting Cold Tolerance.

Complex glycerolipidome analysis of wheat upon low temperature stress has been reported for above-ground tissues only. There are no reports on the effects of cold stress on the root lipidome nor on tissue-specific responses of cold stress wheat roots. This study aims to investigate the changes of lipid profiles in the different developmental zones of the seedling roots of two wheat varieties with contrasting cold tolerance exposed to chilling and freezing temperatures.

Salt stress alters membrane lipid content and lipid biosynthesis pathways in the plasma membrane and tonoplast.

Plant cell membranes are the sites of sensing and initiation of rapid responses to changing environmental factors including salinity stress. Understanding the mechanisms involved in membrane remodeling is important for studying salt tolerance in plants. This task remains challenging in complex tissue due to suboptimal subcellular membrane isolation techniques.

Inoculation of barley with Trichoderma harzianum T-22 modifies lipids and metabolites to improve salt tolerance.

Soil salinity has a serious impact on plant growth and agricultural yield. Inoculation of crop plants with fungal endophytes is a cost-effective way to improve salt tolerance. We used metabolomics to study how Trichoderma harzianum T-22 alleviates NaCl-induced stress in two barley (Hordeum vulgare L.

A comprehensive comparison of four methods for extracting lipids from Arabidopsis tissues.

Background: The plant lipidome is highly complex, and the composition of lipids in different tissues as well as their specific functions in plant development, growth and stress responses have yet to be fully elucidated. To do this, efficient lipid extraction protocols which deliver target compounds in solution at concentrations adequate for subsequent detection, quantitation and analysis through spectroscopic methods are required. To date, numerous methods are used to extract lipids from plant tissues.

Phenotyping the Chilling and Freezing Responses of Young Microspore Stage Wheat Spikes Using Targeted Metabolome and Lipidome Profiling.

Chilling and frost conditions impose major yield restraints to wheat crops in Australia and other temperate climate regions. Unpredictability and variability of field frost events are major impediments for cold tolerance breeding. Metabolome and lipidome profiling were used to compare the cold response in spikes of cold-tolerant Young and sensitive variety Wyalkatchem at the young microspore (YM) stage of pollen development.

Insights Into Oxidized Lipid Modification in Barley Roots as an Adaptation Mechanism to Salinity Stress.

Lipidomics is an emerging technology, which aims at the global characterization and quantification of lipids within biological matrices including biofluids, cells, whole organs and tissues. The changes in individual lipid molecular species in stress treated plant species and different cultivars can indicate the functions of genes affecting lipid metabolism or lipid signaling. Mass spectrometry-based lipid profiling has been used to track the changes of lipid levels and related metabolites in response to salinity stress.

The changes in the release level of polyunsaturated fatty acids (ω-3 and ω-6) and lipids in the untreated and water-soaked chia seed.

Despite recent studies on health benefits of chia seed owing to its high content of ω-3 fatty acids, little work has been conducted on extractability of its nutrients. We examined the effect of soaking chia seed in water on the extractability of its omega fatty acids and lipids. State-of-the-art mass spectrometry techniques including GC-MS, LC-MS, and MALDI-MSI were utilized to identify and determine the spatial distribution of omega fatty acids and lipids in chia seed.

Phenotyping reproductive stage chilling and frost tolerance in wheat using targeted metabolome and lipidome profiling.

Introduction: Frost events lead to A$360 million of yield losses annually to the Australian wheat industry, making improvement of chilling and frost tolerance an important trait for breeding.

Objectives: This study aimed to use metabolomics and lipidomics to explore genetic variation in acclimation potential to chilling and to identify metabolite markers for chilling tolerance in wheat.

Methods: We established a controlled environment screening assay that is able to reproduce field rankings of wheat germplasm for chilling and frost tolerance.

Antibiotic resistance and host immune evasion in mediated by a metabolic adaptation.

is a notorious human bacterial pathogen with considerable capacity to develop antibiotic resistance. We have observed that human infections caused by highly drug-resistant are more prolonged, complicated, and difficult to eradicate. Here we describe a metabolic adaptation strategy used by clinical strains that leads to resistance to the last-line antibiotic, daptomycin, and simultaneously affects host innate immunity.

Identification of Novel Host Fatty Acid Stress Adaptation Strategies.

Free fatty acids hold important immune-modulatory roles during infection. However, the host's long-chain polyunsaturated fatty acids, not commonly found in the membranes of bacterial pathogens, also have significant broad-spectrum antibacterial potential. Of these, the omega-6 fatty acid arachidonic acid (AA) and the omega-3 fatty acid decosahexaenoic acid (DHA) are highly abundant; hence, we investigated their effects on the multidrug-resistant human pathogen Our analyses reveal that AA and DHA incorporate into the bacterial membrane and impact bacterial fitness and membrane integrity, with DHA having a more pronounced effect.

A high-resolution HPLC-QqTOF platform using parallel reaction monitoring for in-depth lipid discovery and rapid profiling.

Here, we developed a robust lipidomics workflow merging both targeted and untargeted approaches on a single liquid chromatography coupled to quadrupole-time of flight (LC-QqTOF) mass spectrometry platform with parallel reaction monitoring (PRM). PRM assays integrate both untargeted profiling from MS1 scans and targeted profiling obtained from MS/MS data. This workflow enabled the discovery of more than 2300 unidentified features and identification of more than 600 lipid species from 23 lipid classes at the level of fatty acid/long chain base/sterol composition in a barley root extracts.

Single cell-type analysis of cellular lipid remodelling in response to salinity in the epidermal bladder cells of the model halophyte Mesembryanthemum crystallinum.

Salt stress causes dramatic changes in the organization and dynamic properties of membranes, however, little is known about the underlying mechanisms involved. Modified trichomes, known as epidermal bladder cells (EBC), on the leaves and stems of the halophyte Mesembryanthemum crystallinum can be successfully exploited as a single-cell-type system to investigate salt-induced changes to cellular lipid composition. In this study, alterations in key molecular species from different lipid classes highlighted an increase in phospholipid species, particularly those from phosphatidylcholine and phosphatidic acid (PA), where the latter is central to the synthesis of membrane lipids.

Extraction of Plant Lipids for LC-MS-Based Untargeted Plant Lipidomics.

Lipids are defined as hydrophobic or amphipathic small molecules which consist of a number of structurally and functionally distinct molecules that span from nonpolar to neutral to polar compounds. Lipidomics is the comprehensive analysis of all lipids in a biological system. Changes in lipid metabolism and composition, as well as of distinct lipid species have been linked with altered plant growth, development, and responses to environmental stresses including salinity.

Phospholipase A2 activity during the replication cycle of the flavivirus West Nile virus.

Positive-sense RNA virus intracellular replication is intimately associated with membrane platforms that are derived from host organelles and comprised of distinct lipid composition. For flaviviruses, such as West Nile virus strain Kunjin virus (WNVKUN) we have observed that these membrane platforms are derived from the endoplasmic reticulum and are rich in (at least) cholesterol. To extend these studies and identify the cellular lipids critical for WNVKUN replication we utilized a whole cell lipidomics approach and revealed an elevation in phospholipase A2 (PLA2) activity to produce lyso-phosphatidylcholine (lyso-PChol).

Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS).

Background: Azithromycin is recommended for the treatment of uncomplicated urogenital chlamydia infection although the standard 1gram dose sometimes fails to eradicate the infection (treatment failure). One hypothesis proposed for treatment failure has been insufficient levels of the antibiotic at the site of infection. We developed an assay using liquid chromatography and tandem mass spectrometry (LC-MS/MS) to measure azithromycin concentration in high-vaginal swabs and monitor how concentration changes over time following routine azithromycin treatment.

Proceedings of 3 Australian Lipid Meeting.

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Lipidomic Profiling of Adipose Tissue Reveals an Inflammatory Signature in Cancer-Related and Primary Lymphedema.

Cancer-related and primary lymphedema (LE) are associated with the production of adipose tissue (AT). Nothing is known, however, about the lipid-based molecules that comprise LE AT. We therefore analyzed lipid molecules in lipoaspirates and serum obtained from LE patients, and compared them to lipoaspirates from cosmetic surgery patients and healthy control cohort serum.

Salt-stress induced alterations in the root lipidome of two barley genotypes with contrasting responses to salinity.

Changes in lipid metabolism and composition as well as in distinct lipid species have been linked with altered plant growth, development and responses to environmental stresses including salinity. However, there is little information available in the literature focusing on lipids in roots under soil-related stresses such as salinity. Barley (Hordeum vulgare L.

Legionella pneumophila S1P-lyase targets host sphingolipid metabolism and restrains autophagy.

Autophagy is an essential component of innate immunity, enabling the detection and elimination of intracellular pathogens. Legionella pneumophila, an intracellular pathogen that can cause a severe pneumonia in humans, is able to modulate autophagy through the action of effector proteins that are translocated into the host cell by the pathogen's Dot/Icm type IV secretion system. Many of these effectors share structural and sequence similarity with eukaryotic proteins.

Liquid-liquid extraction and liquid chromatography-mass spectrometry detection of curcuminoids from bacterial culture medium.

Liquid chromatography-mass spectrometry (LC-MS) has been used to detect polyphenolic curcuminoids found in turmeric but studies of metabolism by bacterial and mammalian cells in vitro are compromised by poor recovery from the culture medium. We report a liquid-liquid extraction procedure with ethyl acetate and use LC-MS to quantify extracted curcuminoids. Ethyl acetate allows recoveries of ∼ 80-86% of curcuminoids from the bacterial growth medium, bacterial cell lysate and combined bacterial cell and growth medium matrices; a clear improvement over acetonitrile where recoveries were ∼ 25-66%.

Degradation of curcuminoids by in vitro pure culture fermentation.

Colonic bacteria may mediate the transformation of curcuminoids, but studies of this metabolism are limited. Here, the metabolism of curcuminoids by Escherichia fergusonii (ATCC 35469) and two Escherichia coli strains (ATCC 8739 and DH10B) was examined in modified medium for colon bacteria (mMCB) with or without pig cecal fluid. LC-MS analysis showed that 16-37% of curcumin, 6-16% of demethoxycurcumin (DMC) and 7-15% of bis-demethoxycurcumin (Bis-DMC), and 7-15% of bis-demethoxycurcumin (Bis-DMC) were converted following 36 h of fermentation, with the amount of curcuminoids degraded varying depending on the bacterial strain and medium used.

Lipidomics: extraction protocols for biological matrices.

Lipidomics is defined as a comprehensive analysis of all lipids in a biological system (lipidome). Lipid profiling is a fast-growing area of research due to the involvements of lipids incorporated with human diseases such as obesity, Alzheimer's diseases, and diabetes as well as in drug discovery. Recently improved liquid chromatography and mass spectrometric techniques has provided the rapid expansion of lipidomics research.

Mechanical cell disruption for lipid extraction from microalgal biomass.

Cell disruption is an integral part of the downstream operation required to produce biodiesel from microalgae. This study investigated the use of ultrasonication and high-pressure homogenization (HPH) as cell disruption methods for two microalgal species, Tetraselmis suecica (TS) and Chlorococcum sp. (C sp.