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Human pathologies are complex and might benefit from a more holistic diagnostic approach than currently practiced. Omics is a concept in biological research that aims to comprehensively characterize and quantify large numbers of biological molecules in complex samples, e.g., proteins (proteomics), low molecular weight molecules (metabolomics), glycans (glycomics) or amphiphilic molecules (lipidomics). Over the past decades, respective unbiased discovery approaches have been intensively applied to investigate functional physiological and pathophysiological relationships in various research study cohorts. In the context of clinical diagnostics, omics approaches seem to have potential in two main areas: (i) biomarker discovery i.e. identification of individual marker analytes for subsequent translation into diagnostics (as classical target analyses with conventional laboratory techniques), and (ii) the readout of complex, higher-dimensional signatures of diagnostic samples, in particular by means of spectrometric techniques in combination with biomathematical approaches of pattern recognition and artificial intelligence for diagnostic classification. Resulting diagnostic methods could potentially represent a disruptive paradigm shift away from current one-dimensional (i.e., single analyte marker based) laboratory diagnostics. The underlying hypothesis of omics approaches for diagnostics is that complex, multigenic pathologies can be more accurately diagnosed via the readout of "omics-type signatures" than with the current one-dimensional single marker diagnostic procedures. While this is indeed promising, one must realize that the clinical translation of high-dimensional analytical procedures into routine diagnostics brings completely new challenges with respect to long-term reproducibility and analytical standardization, data management, and quality assurance. In this article, the conceivable opportunities and challenges of omics-based laboratory diagnostics are discussed. [ABSTRACT FROM AUTHOR]

The molecular identification of the Corynebacterium glutamicum urea uptake system is described. This ABC-type transporter is encoded by the urtABCDE operon, which is transcribed in response to nitrogen limitation. Expression of the urt genes is regulated by the global nitrogen regulator AmtR, and an amtR deletion strain showed constitutive expression of the nrtABCDE genes. The AmtR repressor protein also controls transcription of the urease-encoding ureABCEFGD genes in C. glutamicum. The ure gene cluster forms an operon which is mainly transcribed in response to nitrogen starvation. To confirm the increased synthesis of urease subunits under nitrogen limitation, proteome analyses of cytoplasmic protein extracts from cells grown under nitrogen surplus and nitrogen limitation were carried out, and five of the seven urease subnnits were identified. [ABSTRACT FROM AUTHOR]

In order to utilize different nitrogen sources and to survive situations of nitrogen limitation, microorganisms have developed several mechanisms to adapt their metabolism to changes in the nitrogen supply. In this communication, the use of creatinine as an alternative nitrogen source in Corynebacterium glutamicum, the identification of a membrane protein involved in creatinine uptake, the transcriptional regulation of the corresponding gene, and expression regulation of the gene encoding the creatinine deaminase are reported. As shown by mutant analyses, RNA hybridization experiments and real-time PCR, the expression of two genes, crnT and codA, is increased in response to nitrogen limitation, and regulation depends on the global nitrogen regulator AmtR. In addition, synthesis of creatinine deaminase during nitrogen starvation was shown by two-dimensional gel electrophoresis and MALDI-TOF-MS followed by peptide mass fingerprint analysis. [ABSTRACT FROM AUTHOR]

Well‐regulated placental palmitic acid (PA) and oleic acid (OA) metabolism is vital for optimal placental function and fetal development, but dysregulation occurs with gestational diabetes (GDM). We hypothesized that such dysregulation might arise from increased maternofetal glucose, leptin or insulin concentrations present in GDM, and that dysregulated PA and OA lipid metabolism could be moderated by myo‐inositol, a natural polyol and potential GDM intervention. Placental explants from 21 women were incubated with stable isotope‐labelled 13C‐PA or 13C‐OA for 48 h. Explants were treated with glucose (5, 10 mm) or leptin (13 nm) or insulin (150 nm) in combination with myo‐inositol (0.3, 30, 60 μm). Forty‐seven 13C‐PA lipids and 37 13C‐OA lipids were measured by liquid chromatography–mass spectrometry (LCMS). Compared with controls (5 mm glucose), glucose (10 mm) increased 19 13C‐OA lipids and nine 13C‐PA lipids, but decreased 13C‐OA phosphatidylethanolamine 38:5 and 13C‐PA phosphatidylethanolamine 36:4. The effects of leptin and insulin were less prominent than glucose, with leptin increasing 13C‐OA acylcarnitine 18:1, and insulin increasing four 13C‐PA triacylglycerides. Most glucose, leptin and insulin‐induced alterations in lipids were attenuated by co‐incubation with myo‐inositol (30 or 60 μm), with attenuation also occurring in all subgroups stratified by GDM status and fetal sex. However, glucose‐induced increases in acylcarnitine were not attenuated by myo‐inositol and were even exaggerated in some instances. Myo‐inositol therefore appears to generally act as a moderator, suppressing the perturbation of lipid metabolic processes by glucose, leptin and insulin in placenta in vitro. Whether myo‐inositol protects the fetus and pregnancy from unfavourable outcomes requires further research. Key points: Incubation of placental explants with additional glucose, or to a lesser extent insulin or leptin, alters the placental production of 13C‐lipids from 13C‐palmitic acid (PA) and 13C‐oleic acid (OA) in vitro compared with untreated controls from the same placenta.Co‐incubation with myo‐inositol attenuated most alterations induced by glucose, insulin or leptin in 13C‐lipids, but did not affect alterations in 13C‐acylcarnitines.Alterations induced by glucose and leptin in 13C‐PA triacylglycerides and 13C‐PA phospholipids were influenced by fetal sex and gestational diabetes status, but were all still attenuated by myo‐inositol co‐incubation.Insulin differently affected 13C‐PA triacylglycerides and 13C‐PA phospholipids depending on fetal sex, with alterations also attenuated by myo‐inositol co‐incubation. [ABSTRACT FROM AUTHOR]

Transplacental docosahexaenoic-acid (DHA) supply for fetal development is regulated by placental DHA-lipid metabolism. Both maternal diabetes and obesity are linked to possible decreased fetal circulating DHA and increased placental DHA-lipids. Since myo-inositol is a promising intervention for gestational diabetes (GDM), we aimed to determine whether myo-inositol could rectify perturbations in placental DHA metabolism associated with maternal increasing glycemia and obesity and examine links with birthweight. Term placental villous explants from 17 women representing a range of BMIs and mid-gestational glycemia, were incubated with 13C-labeled-DHA for 48 h, in 0.3 µmol/L (control) or 60 µmol/L myo-inositol. Individual newly synthesized 13C-DHA-labeled lipid species were quantified by liquid-chromatography-mass-spectrometry. Compared with controls, incubation with myo-inositol decreased most 13C-DHA-lipids in placental explants from women with higher BMI or higher glycemia, but increased 13C-DHA-lipids with normal BMI or lower glycemia. Myo-inositol also increased 13C-DHA-labeled lipids in cases of lower birthweight centile, but induced decreases at higher centiles. Myo-inositol therefore lowered DHA-lipids in placenta with high basal placental DHA-lipid production (higher BMI and glycemia) but increased DHA-lipids where basal processing capacity is low. Myo-inositol thus moderates placental DHA metabolism towards a physiological mean which may in turn moderate birthweight. [ABSTRACT FROM AUTHOR]

Hidradenitis suppurativa (HS) is an inflammatory skin condition that is often considered a systemic disease due to its association with metabolic comorbidity. In this study, we aimed to identify differences in plasma lipidomic profiles between HS patients and control subjects. HS patients were recruited from a tertiary dermatological centre and demographic and comorbidity matched controls from the general population. A targeted lipidomic approach was performed to characterize over 700 lipid species representing 35 lipid classes/sub-classes. Linear regression models adjusted for confounding factors were used to compare the plasma lipidomic profiles of HS patients to controls. Ordinal regression models were used to study the association of lipids with disease activity and severity scores. 60 HS patients and 73 control subjects were recruited. Differential levels (p < 0.05) of 32 lipid species in HS patients compared to controls were observed, including a decrease in the long chain base d19:1 containing ceramides, and elevation of hydroxyeicosatetraenoic acid (HETE) and dihydroxyeicosatrienoic acid (DHET) oxylipins. These lipids along with several other molecules showed associations with Hurley, HS-PGA and disease activity scores. This study found mild changes in plasma lipidomic profiles, consistent with previous studies showing attenuated metabolomic changes in plasma as opposed to lesional skin. However, a number of lipid species were associated with increasing activity and severity of the disease. Further, the significant lipid species within the same class showed consistent trends of increase or decrease in HS as compared to controls. • HS patients have differences in plasma lipidomic profiles compared to controls. • Phospholipid species containing linoleic acid were increased in HS. • Decreases in d19:1 long chain base ceramides were observed. • Increases in the proinflammatory oxylipins were also seen in HS. [ABSTRACT FROM AUTHOR]

Complexes formed by the alpha1 N‐terminal peptide of alpha‐lactalbumin and oleic acid (alpha1‐oleate) interact with lipid bilayers. Plasma membrane perturbations trigger tumor cell death but normal differentiated cells are more resistant, and their plasma membranes are less strongly affected. This study examined membrane lipid composition as a determinant of tumor cell reactivity. Bladder cancer tissue showed a higher abundance of unsaturated lipids enriched in phosphatidylcholine, PC (36:4) and PC (38:4), and sphingomyelin, SM (36:1) than healthy bladder tissue, where saturated lipids predominated and the lipid extracts from bladder cancer tissue inhibited the tumoricidal effect of the complex more effectively than healthy tissue extracts. Furthermore, unsaturated PC in solution inhibited tumor cell death, and the complex interacted with giant unilamellar vesicles formed by PC, confirming the affinity of alpha1‐oleate for fluid membranes enriched in PC. Quartz Crystal Microbalance with dissipation monitoring (QCM‐D) detected a preference of the complex for the liquid‐disordered phase, suggesting that the insertion into PC‐based membranes and the resulting membrane perturbations are influenced by membrane lipid saturation. The results suggest that the membrane lipid composition is functionally important and that specific unsaturated membrane lipids may serve as "recognition motifs" for broad‐spectrum tumoricidal molecules such as alpha1‐oleate. [ABSTRACT FROM AUTHOR]

Pregnancy complications such as maternal hyperglycemia increase perinatal mortality and morbidity, but risks are higher in males than in females. We hypothesized that fetal sex-dependent differences in placental palmitic-acid (PA) and oleic-acid (OA) metabolism influence such risks. Placental explants (n = 22) were incubated with isotope-labeled fatty acids (13C-PA or 13C-OA) for 24 or 48 h and the production of forty-seven 13C-PA lipids and thirty-seven 13C-OA lipids quantified by LCMS. Linear regression was used to investigate associations between maternal glycemia, BMI and fetal sex with 13C lipids, and between 13C lipids and birthweight centile. Placental explants from females showed greater incorporation of 13C-OA and 13C-PA into almost all lipids compared to males. Fetal sex also influenced relationships with maternal glycemia, with many 13C-OA and 13C-PA acylcarnitines, 13C-PA-diacylglycerols and 13C-PA phospholipids positively associated with glycemia in females but not in males. In contrast, several 13C-OA triacylglycerols and 13C-OA phospholipids were negatively associated with glycemia in males but not in females. Birthweight centile in females was positively associated with six 13C-PA and three 13C-OA lipids (mainly acylcarnitines) and was negatively associated with eight 13C-OA lipids, while males showed few associations. Fetal sex thus influences placental lipid metabolism and could be a key modulator of the impact of maternal metabolic health on perinatal outcomes, potentially contributing toward sex-specific adaptions in which females prioritize survival. [ABSTRACT FROM AUTHOR]

Background: Lipids play a vital role in health and disease, but changes to their circulating levels and the link with obesity remain poorly characterized in expecting mothers and their offspring in early childhood.Methods: LC-MS/MS-based quantitation of 480 lipid species was performed on 2491 plasma samples collected at 4 time points in the mother-offspring Asian cohort GUSTO (Growing Up in Singapore Towards healthy Outcomes). These 4 time points constituted samples collected from mothers at 26-28 weeks of gestation (n=752) and 4-5 years postpartum (n=650), and their offspring at birth (n=751) and 6 years of age (n=338). Linear regression models were used to identify the pregnancy and developmental age-specific variations in the plasma lipidomic profiles, and their association with obesity risk. An independent birth cohort (n=1935), the Barwon Infant Study (BIS), comprising mother-offspring dyads of Caucasian origin was used for validation.Results: Levels of 36% of the profiled lipids were significantly higher (absolute fold change > 1.5 and Padj < 0.05) in antenatal maternal circulation as compared to the postnatal phase, with phosphatidylethanolamine levels changing the most. Compared to antenatal maternal lipids, cord blood showed lower concentrations of most lipid species (79%) except lysophospholipids and acylcarnitines. Changes in lipid concentrations from birth to 6 years of age were much higher in magnitude (log2FC=-2.10 to 6.25) than the changes observed between a 6-year-old child and an adult (postnatal mother) (log2FC=-0.68 to 1.18). Associations of cord blood lipidomic profiles with birth weight displayed distinct trends compared to the lipidomic profiles associated with child BMI at 6 years. Comparison of the results between the child and adult BMI identified similarities in association with consistent trends (R2=0.75). However, large number of lipids were associated with BMI in adults (67%) compared to the children (29%). Pre-pregnancy BMI was specifically associated with decrease in the levels of phospholipids, sphingomyelin, and several triacylglycerol species in pregnancy.Conclusions: In summary, our study provides a detailed landscape of the in utero lipid environment provided by the gestating mother to the growing fetus, and the magnitude of changes in plasma lipidomic profiles from birth to early childhood. We identified the effects of adiposity on the circulating lipid levels in pregnant and non-pregnant women as well as offspring at birth and at 6 years of age. Additionally, the pediatric vs maternal overlap of the circulating lipid phenotype of obesity risk provides intergenerational insights and early opportunities to track and intervene the onset of metabolic adversities.Clinical Trial Registration: This birth cohort is a prospective observational study, which was registered on 1 July 2010 under the identifier NCT01174875 . [ABSTRACT FROM AUTHOR]

Background: Fetal docosahexaenoic acid (DHA) supply relies on preferential transplacental transfer, which is regulated by placental DHA lipid metabolism. Maternal hyperglycemia and obesity associate with higher birthweight and fetal DHA insufficiency but the role of placental DHA metabolism is unclear. Methods: Explants from 17 term placenta were incubated with 13C-labeled DHA for 48 h, at 5 or 10 mmol/L glucose treatment, and the production of 17 individual newly synthesized 13C-DHA labeled lipids quantified by liquid chromatography mass spectrometry. Results: Maternal BMI positively associated with 13C-DHA-labeled diacylglycerols, triacylglycerols, lysophospholipids, phosphatidylcholine and phosphatidylethanolamine plasmalogens, while maternal fasting glycemia positively associated with five 13C-DHA triacylglycerols. In turn, 13C-DHA-labeled phospholipids and triacylglycerols positively associated with birthweight centile. In-vitro glucose treatment increased most 13C-DHA-lipids, but decreased 13C-DHA phosphatidylethanolamine plasmalogens. However, with increasing maternal BMI, the magnitude of the glucose treatment induced increase in 13C-DHA phosphatidylcholine and 13C-DHA lysophospholipids was curtailed, with further decline in 13C-DHA phosphatidylethanolamine plasmalogens. Conversely, with increasing birthweight centile glucose treatment induced increases in 13C-DHA triacylglycerols were exaggerated, while glucose treatment induced decreases in 13C-DHA phosphatidylethanolamine plasmalogens were diminished. Conclusions: Maternal BMI and glycemia increased the production of different placental DHA lipids implying impact on different metabolic pathways. Glucose-induced elevation in placental DHA metabolism is moderated with higher maternal BMI. In turn, findings of associations between many DHA lipids with birthweight suggest that BMI and glycemia promote fetal growth partly through changes in placental DHA metabolism. [ABSTRACT FROM AUTHOR]

We postulate that myo-inositol, a proposed intervention for gestational diabetes, affects transplacental lipid supply to the fetus. We investigate d the effect of myoinositol on fatty acid processing in human placental explants from uncomplicated pregnancies. Explants were incubated with 13C-labeled palmitic acid, 13C-oleic acid and 13C-docosahexaenoic acid across a range of myo-inositol concentrations for 24 h and 48 h. The incorporation of labeled fatty acids into in dividual lipids was quantified by liquid chromatography mass spectrometry. At 24 h, myo-inositol increased the amount of 13C-palmitic acid and 13C-oleic-acid labeled lipids (median fold change relative to control = 1). Significant effects were seen with 30 µM myo-inositol (physiological) for 13C-palmitic acid-lysophosphatidylcholines (1.26) and 13C-palmitic acidphosphatidylethanolamines (1.17). At 48 h, myo-inositol addition increased 13C-oleic-acidlipids but decreased 13C-palmitic acid and 13C-docosahexaenoic-acid lipids. Significant effects were seen with 30 µM myo-inositol for 13C-oleic-acid-phosphatidylcholines (1.25), 13C-oleic-acid-phosphatidylethanolamines (1.37) and 13C-oleic-acid-triacylglycerols (1.32) and with 100 µM myo-inositol for 13C-docosahexaenoic-acid-triacylglycerols (0.78). Lipids labeled with the same 13C-fatty acid showed similar responses when tested at the same time point, suggesting myo-inositol alters upstream processes such as fatty acid uptake or activation. Myo-inositol supplementation may alter placental lipid physiology with unknown clinical consequences. [ABSTRACT FROM AUTHOR]

Phosphate plays a central role in the environment and in biology. This has led to the demand for a specific phosphate receptor that can be used to sense, enrich or separate phosphate and phosphorylated molecules from complex mixtures. Here, we report an approach for the production of phospho-affinity porous beads with controllable size and pore structure leading to significantly improved chromatographic properties. The beads were prepared by polymerization of bis-imidazolium based host monomer and crosslinker inside the pores of macroporous silica beads that post-etching resulted in mesoporous polymer replicas. The silica precursor, silica–polymer composite and porous polymer replica were characterized by using SEM, IR spectroscopy, optical microscopy and thermogravimetric analysis. Bis-imidazolium functionalized materials were capable of binding and enriching the signaling lipid sphingosine-1-phosphate from plasma samples. Moreover, these engineered materials combined with artificial receptors can recognize phosphorylated amino acids/peptides and are applicable to selective recognition of a broad class of phosphorylated biomolecules. [ABSTRACT FROM AUTHOR]

Glucocorticoids (GCs) are critical regulators of metabolic control in mammals and their aberrant function has been linked to several pathologies. GCs are widely used in human and veterinary clinical practice as potent anti-inflammatory and immune suppressive agents. Dyslipidaemia is a frequently observed consequence of GC treatment, typified by increased lipolysis, lipid mobilization, liponeogenesis, and adipogenesis. Dogs with excess GC show hyperlipidaemia, hypertension, and a higher risk of developing type 2 diabetes mellitus, but the risk of developing atherosclerotic lesions is low as compared to humans. This study aimed to examine alterations in the canine plasma lipidome in a model of experimentally induced short-term and long-term GC excess. Both treatments led to significant plasma lipidome alterations, which were more pronounced after long-term excess steroid exposure. In particular, monohexosylceramides, phosphatidylinositols, ether phosphatidylcholines, acyl phosphatidylcholines, triacylglycerols and sphingosine 1-phosphates showed significant changes. The present study highlights the hitherto unknown effects of GCs on lipid metabolism, which will be important in the further elucidation of the role and function of GCs as drugs and in metabolic and cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Mycobacteria store triacylglycerols (TGs) under various stress conditions, such as hypoxia, exposure to nitric oxide, and acidic environments. These stress conditions are known to induce nonreplicating persistence in mycobacteria. The importance of TG accumulation and utilization during regrowth is not clearly understood. Here we specifically determined the levels of accumulated TG and TG lipase activity in Mycobacterium bovis bacillus Calmette-Guerin (BCG) in various different physiological states (logarithmic growth, aerated stationary phase, hypoxia-induced dormancy, and regrowth from dormancy). We found extensive accumulation and degradation of TGs in the bacilli during entry into and exit from hypoxia-induced dormancy, respectively. These processes are accompanied by dynamic appearance and disappearance of intracellular TG lipid particles. The reduction in TG levels coincides with an increase in cellular TG lipase activity in the regrowing bacilli. Tetrahydrolipstatin, an inhibitor of TG lipases, reduces total lipase activity, prevents breakdown of TGs, and blocks the growth of mycobacteria upon resuscitation with air. Our results demonstrate that utilization of TGs is essential for the regrowth of mycobacteria during their exit from the hypoxic nonreplicating state. [ABSTRACT FROM AUTHOR]