Condition Monitoring of a Vessel’s Main Engine: A Case Study

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Serum lipidomic analysis for the discovery of biomarkers for major depressive disorder in drug-free patients.

Lipidomic analysis can be used to efficiently identify hundreds of lipid molecular species in biological materials and has been recently established as an important tool for biomarker discovery in various neuropsychiatric disorders including major depressive disorder (MDD). In this study, quantitative targeted serum lipidomic profiling was performed on female subjects using liquid chromatography-mass spectrometry. Global lipid profiling of pooled serum samples from 10 patients currently with MDD (cMDD), 10 patients with remitted MDD (rMDD), and 10 healthy controls revealed 37 differentially regulated lipids (DRLs). DRLs were further verified using multiple-reaction monitoring (MRM) in each of the 25 samples from the three groups of independent cohorts. Using multivariate analysis and MRM data we identified serum biomarker panels of discriminatory lipids that differentiated between pairs of groups: lysophosphatidic acid (LPA)(16:1), triglycerides (TG)(44:0), and TG(54:8) distinguished cMDD from controls with 76% accuracy; lysophosphatidylcholines(16:1), TG(44:0), TG(46:0), and TG(50:1) distinguished between cMDD and rMDD at 65% accuracy; and LPA(16:1), TG(52:6), TG(54:8), and TG(58:10) distinguished between rMDD and controls with 60% accuracy. Our lipidomic analysis identified peripheral lipid signatures of MDD, which thereby provides providing important biomarker candidates for MDD

Proteomic analysis of extracellular vesicles derived from Propionibacterium acnes

Purpose: Extracellular vesicle (EV) has been reported to conduct critical pathophysiological functions as an emerging mode of communication in bacteria. Recently, Propionibacterium acnes, an anaerobic Gram-positive human commensal found in the skin and gastrointestinal tract, has drawn increasing attention as an underestimated pathogen in a variety of diseases. Experimental design: For the comprehensive understanding of P. acnes, here we report the isolation of P. acnes EVs for the first time and identification of 252 vesicular proteins with high confidence using triplicate LC-MS/MS analyses. Result: Comprehensive proteomic profiling reveals that P. acnes EVs harbor various proteins involved in biochemical processes, antibiotic resistance, bacterial competition, cell adherence, virulence, and immunogenicity. Conclusion and clinical relevance: We believe that this report will provide valuable information for investigating the biological role of P. acnes EVs and effective targets for developing clinical applications against P. acnes.116sciescopu

Analysis of the Phospholipid Profile of Metaphase II Mouse Oocytes Undergoing Vitrification

<div><p>Oocyte freezing confers thermal and chemical stress upon the oolemma and various other intracellular structures due to the formation of ice crystals. The lipid profiles of oocytes and embryos are closely associated with both, the degrees of their membrane fluidity, as well as the degree of chilling and freezing injuries that may occur during cryopreservation. In spite of the importance of lipids in the process of cryopreservation, the phospholipid status in oocytes and embryos before and after freezing has not been investigated. In this study, we employed mass spectrometric analysis to examine if vitrification has an effect on the phospholipid profiles of mouse oocytes. Freshly prepared metaphase II mouse oocytes were vitrified using copper grids and stored in liquid nitrogen for 2 weeks. Fresh and vitrified-warmed oocytes were subjected to phospholipid extraction procedure. Mass spectrometric analyses revealed that multiple species of phospholipids are reduced in vitrified-warmed oocytes. LIFT analyses identified 31 underexpressed and 5 overexpressed phospholipids in vitrified mouse oocytes. The intensities of phosphatidylinositol (PI) {18∶2/16∶0} [M−H]− and phosphatidylglycerol (PG) {14∶0/18∶2} [M−H]− were decreased the most with fold changes of 30.5 and 19.1 in negative ion mode, respectively. Several sphingomyelins (SM) including SM {d38∶3} [M+H]+ and SM {d34∶0} [M+K]+ were decreased significantly in positive ion mode. Overall, the declining trend of multiple phospholipids demonstrates that vitrification has a marked effect on phospholipid profiles of oocytes. These results show that the identified phospholipids can be used as potential biomarkers of oocyte undergoing vitrification and will allow for the development of strategies to preserve phospholipids during oocyte cryopreservation.</p></div

Age-Associated Lipidome Changes in Metaphase II Mouse Oocytes

<div><p>The quality of mammalian oocytes declines with age, which negatively affects fertilization and developmental potential. The aging process often accompanies damages to macromolecules such as proteins, DNA, and lipids. To investigate if aged oocytes display an altered lipidome compared to young oocytes, we performed a global lipidomic analysis between oocytes from 4-week-old and 42 to 50-week-old mice. Increased oxidative stress is often considered as one of the main causes of cellular aging. Thus, we set up a group of 4-week-old oocytes treated with hydrogen peroxide (H₂O₂), a commonly used oxidative stressor, to compare if similar lipid species are altered between aged and oxidative-stressed oocytes. Between young and aged oocytes, we identified 26 decreased and 6 increased lipids in aged oocytes; and between young and H₂O₂-treated oocytes, we identified 35 decreased and 26 increased lipids in H₂O₂-treated oocytes. The decreased lipid species in these two comparisons were overlapped, whereas the increased lipid species were distinct. Multiple phospholipid classes, phosphatidic acid (PA), phosphatidylinositol (PI), phosphatidylserine (PS), and lysophosphatidylserine (LPS) significantly decreased both in H₂O₂-treated and aged oocytes, suggesting that the integrity of plasma membrane is similarly affected under these conditions. In contrast, a dramatic increase in diacylglycerol (DG) was only noted in H₂O₂-treated oocytes, indicating that the acute effect of H₂O₂-caused oxidative stress is distinct from aging-associated lipidome alteration. In H₂O₂-treated oocytes, the expression of lysophosphatidylcholine acyltransferase 1 increased along with increases in phosphatidylcholine. Overall, our data reveal that several classes of phospholipids are affected in aged oocytes, suggesting that the integrity of plasma membrane is associated with maintaining fertilization and developmental potential of mouse oocytes.</p></div

Experimental design and BODIPY/CellMask staining of mouse oocytes prior to and after vitrification.

<p>(A) A schematic diagram showing the experimental design and the three experimental groups. Two sets of vitrified-warmed oocytes with matching controls (represented as Set 1 and Set 2 in the diagram) were used. Since phospholipid extraction and subsequent analyses were performed on the day of oocyte preparation, the 2^nd control groups were prepared on the day of thawing vitrified oocytes of the previous set. Another set of control oocytes were prepared when extracting phospholipids from vitrified-warmed oocytes of the 2^nd set. This was added to ensure the quality of phospholipid extraction and analyses. Mass spectrometric analyses were performed in all groups shown. For statistical analysis, two full sets of data (shown in beige areas) excluding the last set of controls (shown in gray boxes) were included. (B) Fresh MII oocytes, solution-treated oocytes, and vitrified-warmed oocytes (2-week vitrification) were stained with BODIPY 500/510 (10 µg/ml) and CellMask (2.5 µg/ml). Stained oocytes were washed with media and examined under a confocal microscope without fixation. BODIPY and CellMask are shown in green and red, respectively. The experiment was repeated more than three times with different pools of oocytes. Representative images are shown. Red scale bar, 20 µm.</p

Principal component analysis plots for the phospholipid mass spectra.

<p>Fresh oocytes, green dots; 2-week vitrification, red dots.</p

Fragmentation spectra of representative phospholipid species by using the LIFT technique.

<p>(A) m/z 782.6; PC {34∶1} [M+Na]+ in positive ion mode and (B) m/z 861.6; PI {18∶0/18∶2} [M−H]− in negative ion mode. Fragmentation spectra for other phospholipids are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0102620#pone.0102620.s003" target="_blank">Fig. S3</a>.</p

Relative intensities of differentially expressed phospholipids in fresh and vitrified oocytes measured by MALDI-TOF MS in (A) positive ion mode and in (B) negative ion mode.

<p>Red dots, phospholipid species with fold changes greater than 2 (<i>p</i><0.01). (C) Phospholipids that are significantly reduced after vitrification and warming. Fold changes greater than 3 are shown (<i>p</i><0.01).</p

Differentially expressed phospholipids between fresh oocytes and vitrified oocytes (2 weeks).

<p><i>*Ratio,</i> Fresh oocytes/2 weeks vitrified oocytes.</p><p><i>*P</i>, <i>p</i> value.</p><p>*PC, Phosphatidylcholines.</p><p>*SM, Sphingomyelins.</p><p>*LPC, Lysophosphatidylcholine.</p><p>*PI, Phosphatidylinositol.</p><p>*PG, Phosphatidylglycerol.</p><p>*LPI, Lysophosphatidylinositol.</p><p>*PE, Phosphatidylethanolamine.</p