Project description:Human activities and climate change have negatively affected the world's oceans, leading to a 30-60% decline in biodiversity and habitats in coastal ecosystems. Marine turtles, as bioindicator species, accumulate contaminants, including trace elements, due to their extensive migration and long life span. However, there is a lack of data on the abundance of these contaminants and their effects on marine turtles' health. This study focuses on analyzing the muscle proteome of juvenile green sea turtles (Chelonia mydas) from Reunion Island. The ultimate goal was to evaluate whether muscle proteome responds to in-situ mixtures of inorganic contaminants to decipher the possible impacts on individual health, thereby identifying potential new biomarkers for long-term monitoring and conservation efforts.
Project description:The erythroblastic island (EBI), composed of a central macrophage and surrounding erythroid cells, was the first hematopoietic niche discovered. The identity of EBI macrophages has thus far remained elusive. Gene expression profiles of BM F4/80+Epor-eGFP+ macrophages suggest a specialized function in supporting erythropoiesis.
Project description:We performed a comprehensive fecal metabolite analysis using LC-MS/MS and LC-QTOF-MS approaches as a preliminary study. Feces of Japanese macaques on Yakushima Island were collected from five monkeys at two separate locations. Using the former methodology, 59 substances such as free amino acids, nucleotides, nucleosides and nucleic acid bases, and organic acids in the citrate cycle were quantitatively detected and successfully differentiated in two different monkey groups by the concentrations of nucleic acid metabolites and free amino acids. In the latter, around 12,000 substances were detected both by positive and negative mode in each sample. Differences in signal intensities were observed between two monkey groups in the concentrations of plant secondary metabolites such as cyanogenic glycosides, flavonoids, and phenolics.
Project description:In this study, both conventional one-dimensional liquid chromatography (1DLC) and comprehensive two-dimensional liquid chromatography (2DLC) coupled to a high-resolution time-of-flight mass spectrometer (HR-TOF MS) were used for full-scale lipid characterization of lipid extracts from zebrafish embryos. We investigated the influence on annotated lipids and different separation mechanisms (HILIC, C18, and PFP), and their different orders arranged in the first and the second dimensions. As a result, the number of lipid species annotated by conventional one-dimensional LC-MS was between 212 and 448. In contrast, the number of individual lipids species annotated by C18×HILIC, HILIC×C18, and HILIC×PFP were 1784, 1059, and 1123, respectively. Therefore, it was evident that the performance of comprehensive 2DLC, especially the C18×HILIC method, considerably exceeded 1DLC. Interestingly, a comparison of the HILIC×C18 and C18×HILIC approaches showed, under the optimized conditions, similar orthogonality, but the effective separation power of the C18×HILIC was much higher. A comparison of the HILIC×C18 and the HILIC×PFP methods demonstrated that the HILIC×PFP separation had superior orthogonality with a small increase on its effective peak capacity, indicating that the HILIC×PFP combination maybe a promising platform for untargeted lipidomics in complex samples. Finally, from the comprehensive lipid profiling respective, the C18×HILIC was selected for further studies.
Project description:We have developed and validated a novel LC-MS/MS method for simultaneously analyzing amino acids, biogenic amines, and their acetylated and methylated derivatives in plants. This method involves a one-step extraction of 2-5 mg of lyophilized plant material followed by fractionation of different biogenic amine forms, and exploits an efficient combination of hydrophilic interaction liquid chromatography (HILIC), reversed phase (RP) chromatography with pre-column derivatization, and tandem mass spectrometry (MS). This approach enables high-throughput processing of plant samples, significantly reducing the time needed for analysis and its cost. We also present a new synthetic route for deuterium-labeled polyamines. The LC-MS/MS method was rigorously validated by quantifying levels of nitrogen-related metabolites in seedlings of seven plant species, including Arabidopsis, maize, and barley, all of which are commonly used model organisms in plant science research. Our results revealed substantial variations in the abundance of these metabolites between species, developmental stages, and growth conditions, particularly for the acetylated and methylated derivatives and the various polyamine fractions. However, the biological relevance of these plant metabolites is currently unclear. Overall, this work contributes significantly to plant science by providing a powerful analytical tool and setting the stage for future investigations into the functions of these nitrogen-related metabolites in plants.
Project description:Liquid chromatography-mass spectrometry (LC-MS/MS) based approaches are widely used for the identification and quantitation of specific metabolites, and are a preferred approach towards analyzing cellular metabolism. Most methods developed come with specific requirements such as unique columns, ion-pairing reagents and pH conditions, and typically allow measurements in a specific pathway alone. Here, we present a single column-based set of methods for simultaneous coverage of multiple pathways, primarily focusing on central carbon, amino acid, and nucleotide metabolism. We further demonstrate the use of this method for quantitative, stable isotope-based metabolic flux experiments, expanding its use beyond steady-state level measurements of metabolites. The expected kinetics of label accumulation pertinent to the pathway under study are presented with some examples. The methods discussed here are broadly applicable, minimize the need for multiple chromatographic resolution methods, and highlight how simple labeling experiments can be valuable in facilitating a comprehensive understanding of the metabolic state of cells.
Project description:Highly polar pesticides (HPP) are a group of pesticides that are characterize as low Log Kow. Many high-throughput multi-residue analysis methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous determination of such polar pesticides have been proposed. In this article, we summarize the various sample preparation methods including quick polar pesticides (QuPPe), dispersive solid phase extraction (dSPE), solid phase extraction (SPE) and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe), especially for QuPPe, which are mainly used for the determination of HPP in foods. In addition, we summarize LC-based separation methodologies that are currently used for the analysis of HPP in foods, including reversed-phase chromatography (RPC), hydrophilic interaction liquid chromatography (HILIC), ion chromatography (IC) and mixed-mode chromatography (MMC). Finally, the current mass spectrometry-based methodologies for the analysis of HPP are summarized with a specific focus on MS configurations and acquisition modes.