Aspartic Acid Levels Research Articles

Insights into the role of cyclopropane fatty acid synthase (CfaS) from extreme acidophile in bacterial defense against environmental acid stress.

The cell membrane remodeling mediated by cyclopropane fatty acid synthase (CfaS) plays a crucial role in microbial physiological processes resisting various environmental stressors, including acid. Herein, we found a relatively high proportion (24.8%-28.3%) of cyclopropane fatty acid (CFA) Cy-19:0 in the cell membrane of a newly isolated extreme acidophile, Acidithiobacillus caldus CCTCC AB 2019256, under extreme acid stress. Overexpression of the CfaS encoding gene cfaS2 in Escherichia coli conferred enhanced acid resistance. GC-MS analysis revealed a 3.52-fold increase in the relative proportion of Cy-19:0 in the cell membrane of the overexpression strain compared to the control. Correspondingly, membrane fluidity, permeability and cell surface hydrophobicity were reduced to varying degrees. Additionally, HPLC analysis indicated that the overexpression strain had 1.54-, 1.42-, 1.85-, 1.20- and 1.05-fold higher levels of intracellular glutamic acid, arginine, aspartic acid, methionine and alanine, respectively, compared to the control. Overall, our findings shed light on the role of CfaS derived from extreme acidophile in bacterial defense against environmental acid stress, potentially facilitating its application in the design and development of industrial microbial chassis cells for organic acid production.

Nutrient profile, protease and cellulase activities of protein extracted from black soldier fly (Hermetia illucens) larvae reared on various substrates

The Black Soldier Fly (BSF; Hermetia illucens) larvae are recognized for their ability to convert diverse organic materials into protein-rich biomass, depending on the substrate they consume. The composition of these substrates can significantly impact the nutrient profile and enzyme activities of the resulting maggot protein extract (MPE). Therefore, this exploratory research aimed to assess the nutrient content, protease, and cellulase activity of MPE obtained from BSF maggots reared on different substrates, with a specific focus on substrates A (comprising restaurant waste and rejected milk), B (layer manure), and C (kitchen waste). The results showed that maggot meal from layer manure had the highest protein content (45.36%) and the lowest fat content (18.44%). Amino acids in maggot meal contained high levels of glutamic acid, aspartic acid, alanine, valine, leucine, and isoleucine. Lauric acids were found in maggot meal from kitchen waste (33.79%), layer manure (32.18%), and restaurant waste and rejected milk (22.94%). Maggot meal from layer manure had the highest oleic acid content (15.13%). The protein concentration of MPE from various substrates ranged from 0.56 to 0.601 mg/ml (at 60% w/v ammonium sulfate saturation) and 0.555 to 0.609 mg/ml (at 70% ammonium sulfate saturation). The protease activity of MPE from layer manure substrates exhibited optimum activity and stability in neutral to alkaline pH, with activity levels of 0.748 U/mg at pH 7.0 and pH 11.0 (at 60% w/v ammonium sulfate saturation) and 0.774 units/mg at 70% w/v ammonium sulfate saturation. The highest cellulase activity was found in MPE from kitchen waste, which remained stable at pH 5.0-11.0. In general, maggots from different substrate sources exhibited distinct nutrient profiles and enzyme activities. Protein extract from maggots grown in layer manure showed the most suitable nutrient profile for use as an alternative source of protein feed and protease enzymes.

Metabolic profiling of psoriasis vulgaris and palmoplantar pustulosis.

Psoriasis is a chronic inflammatory skin disorder with various subtypes, including psoriasis vulgaris (PV) and palmoplantar pustulosis (PPP). Metabolomics studies have provided insights into psoriasis pathogenesis. However, research on metabolomic alterations in PV and PPP patients is limited. We aimed to explore and compare the metabolic profiles of patients with PV and PPP to those of healthy volunteers (HVs). A single-centre retrospective cohort was constructed, comprising Korean patients with psoriasis and HVs matched by age and sex. Clinical information including demographics, disease severity, and comorbidities were collected. Plasma samples were subjected to targeted metabolic analysis using an Absolute IDQ®p180 kit, which quantified 188 metabolites, including amino acids and carnitines. Statistical significance was assessed using an independent t-test and chi-square test, with p-values adjusted by the Benjamini-Hochberg procedure. Pathway analyses were employed to gain a comprehensive understanding of the metabolite profile. This study included 93 patients (73 PV and 20 PPP) and an equal number of HVs. PV patients showed increased levels of sarcosine, serotonin, propionylcarnitine, proline, aspartic acid, tyrosine, taurine, spermine and ornithine, but exhibited a decreased level of acetylcarnitine than matched HVs. Notably, sarcosine levels were significantly elevated in PPP patients. Furthermore, the sarcosine/glycine ratio was significantly higher in both PV and PPP patients than in HVs. Pathway analysis showed significant increases in metabolites involved in amino acid metabolism and the urea cycle in PV patients. In conclusion, this study demonstrated distinct metabolic profiles in PV and PPP patients compared to HVs, suggesting sarcosine as a potential biomarker for psoriasis.

Unveiling the altered metabolic pathways induced by nivolumab in non-small cell lung cancer via GC–MS metabolomics approach coupled with multivariate analysis

This research investigates the effects of the immunotherapeutic agent nivolumab on the metabolism of lung cancer cells (NCI-H1975) using GC–MS metabolomic profiling. Multivariate analysis such as unsupervised PCA and supervised OPLS-DA along with univariate analysis and pathway analysis were employed to explore the metabolomic data and identify altered metabolic pathways induced by nivolumab treatment. The study revealed distinct metabolic alterations in cancer cells, linked to proliferative and survival advantages, such as enhanced glycolysis, increased glutaminolysis, and modified amino acid metabolism. Key findings indicate elevated levels of glycolysis-related metabolites (glycine, alanine, pyruvate, and lactate) and TCA cycle intermediates (succinate, fumarate, malate) in cancer cells, with a significant decrease following nivolumab treatment. Additionally, lower levels of aspartic acid and citrate in cancer cells imply altered nucleotide synthesis and fatty acid production essential for tumor growth. Treatment with nivolumab also reduced oleic acid levels, indicative of its effect on disrupted lipid metabolism. Our research shows nivolumab's potential to modify metabolic pathways involved in lung cancer progression, suggesting its dual role in cancer therapy: as an immune response modulator and a metabolic pathway disruptor.

The osmoregulatory mechanism in response to hypoosmotic stress and the key role of ABCC1 in osmoregulation in the mud crab, Scylla paramamosain

Scylla paramamosain is an important mariculture animal. In the present study, we examined the physiological and biochemical characteristics of juvenile S. paramamosain under hypoosmotic stress and further verified the function of ABCC1, a key transport protein in gill tissue. The results showed that Na+/K+-ATPase, Ca2+-ATPase, and Na+/K+/2Cl- cotransporter in gill tissues increased first and then decreased. In addition, SOD and CAT activities also began to gradually increase, protecting gill tissues from oxidative damage. The hemolymph osmolarity decreased rapidly from 792 mOsm/kg to 560 mOsm/kg within 6 h, and then rose to 626.25 mOsm/kg at 48 h, and then remained stable. At the same time, Na+, Cl-, K+, and Ca2+ concentrations were decreased to varying degrees. There were significant changes in free amino acids such as aspartic acid, glutamic acid, and asparagine in hemolymph in response to acute salt depletion. By injection of ABCC1 inhibitor/activator, it was found that while ABCC1 transporter activity in the MK-571 group showed a decreasing trend at 9 h, Na+/K+ -ATPase activity began to increase and reached a peak at 48 h. Compared with the control group, the levels of aspartic acid, glutamic acid, asparagine, glycine, arginine, alanine, lysine, and proline in the MK-571 group showed significant differences at 6 h; Significant differences in glutamate, asparagine, arginine, alanine, lysine, and proline appeared at 12 h in the Thiethylperazine group. These results suggested that the dynamic changes of gill ion transport enzymes, antioxidant enzymes, inorganic ions, and free amino acids in hemolymph occurred in S. paramamosain under hypoosmotic stress, and the ABCC1 transporter played an important role in this regulatory process.

The potential Two Types of Green Macroalgae (Caulerpa racemose and Caulerpa lentillifera) as a Natural Food Preservative from Jepara beach, Indonesia

Green macroalgae, known locally as Latoh, is one of the green seaweeds consumed by the local community in Jepara and is beneficial for health. This study explores the potential of secondary metabolites from seaweed and its symbiotic bacteria as natural food preservatives and antibacterials. Seaweed samples were collected from the seagrass ecosystem of Panjang Island, Jepara, Indonesia. Subsequently, the samples were subjected to scanning electron microscopy analysis, proximate analysis, phytochemical analysis, thin layer chromatography, and high-performance liquid chromatography for amino acid analysis. A sample was subjected to a multistage extraction process using n-hexane, ethyl acetate, and methanol (1:5 w/v), each for 24 h. Symbiotic bacteria from seaweed were isolated, and enzymatic (proteolytic, amylolytic, and cellulolytic) and antibacterial testing against pathogenic bacteria Staphylococcus aureus and Escherichia coli was conducted using the disc diffusion method. The selected bacteria were subjected to molecular identification. The research showed that Caulerpa lentillifera had an ash content of 3.24 %, protein content of 0.57 %, and fat content of 0.337 %. Phytochemical analysis shows that the sample contains flavonoids, steroids, and alkaloids. HPLC analysis reveals that Caulerpa lentillifera has the highest content of aspartic acid (relative area: 11.90 %), glutamic acid (relative area: 13.43 %), and alanine (relative area: 9.03 %). Caulerpa racemosa sample shows the highest detector response for glutamic acid (relative area: 12.19%), aspartic acid (relative area: 11.10 %), and alanine (relative area: 9.63 %). The results indicate that 14 bacterial isolates were successfully isolated, with 6 isolates from Caulerpa lentillifera and 8 isolates from Caulerpa racemosa, all exhibiting enzymatic and antibacterial abilities. The research results concluded that the Latoh seaweed species Caulerpa lentillifera and Caulerpa racemosa and their symbiotic bacteria have the potential to be used as food preservatives. HIGHLIGHTS HPLC analysis showed that Caulerpa lentillifera had the highest content of aspartic acid, glutamic acid, and alanine. Caulerpa racemosa also had high levels of glutamic acid, aspartic acid, and alanine The research successfully isolated 14 bacterial isolates, with 6 isolates from Caulerpa lentillifera and eight isolates from Caulerpa racemosa, all exhibiting enzymatic and antibacterial abilities Molecular identification revealed the presence of identified bacteria such as Pseudoalteromonas arabiensis, Pseudoalteromonas piscicida, Pseudoalteromonas shioyasakiensis, and Vibrio alginolyticus seaweed species Caulerpa lentillifera and Caulerpa racemosa, along with their symbiotic bacteria, have the potential to be used as natural food preservatives due to their antibacterial and enzymatic pro perties GRAPHICAL ABSTRACT

Changes in the serum metabolomics of polycystic ovary syndrome before and after compound oral contraceptive treatment.

Polycystic ovary syndrome (PCOS) is both a common endocrine syndrome and a metabolic disorder that results in harm to the reproductive system and whole-body metabolism. This study aimed to investigate differences in the serum metabolic profiles of patients with PCOS compared with healthy controls, in addition to investigating the effects of compound oral contraceptive (COC) treatment in patients with PCOS. 50 patients with PCOS and 50 sex-matched healthy controls were recruited. Patients with PCOS received three cycles of self-administered COC treatment. Clinical characteristics were recorded, and the laboratory biochemical data were detected. We utilized ultra-performance liquid chromatography-high-resolution mass spectrometry to study the serum metabolic changes between patients with PCOS, patients with PCOS following COC treatment, and healthy controls. Patients with PCOS who received COC treatment showed significant improvements in serum sex hormone levels, a reduction in luteinising hormone levels, and a significant reduction in the levels of biologically active free testosterone in the blood. Differential metabolite correlation analysis revealed differences between PCOS and healthy control groups in N-tetradecanamide, hexadecanamide, 10E,12Z-octadecadienoic acid, and 13-HOTrE(r); after 3 months of COC treatment, there were significant differences in benzoic acid, organic acid, and phenolamides. Using gas chromatography-mass spectrometry to analyse blood serum in each group, the characteristic changes in PCOS were metabolic disorders of amino acids, carbohydrates, and purines, with significant changes in the levels of total cholesterol, uric acid, phenylalanine, aspartic acid, and glutamate. Following COC treatment, improvements in sex hormone levels, endocrine factor levels, and metabolic levels were better than in the group of PCOS patients receiving no COC treatment, indicating that COC treatment for PCOS could effectively regulate the levels of sex hormones, endocrine factors, and serum metabolic profiles.

Untargeted UHPLC-MS deferential screening method and targeted UHPLC-MS/MS quantitative method for the determination of amino acids in mouse brain tissue

An untargeted UHPLC-MS method was developed for the preliminary screening of differential amino acids between two mouse brain tissue samples, and a targeted UHPLC-MS/MS method was developed for the quantitative determination of amino acids in mouse brain tissue samples. The sample processing procedure, chromatographic conditions and MS parameters were optimized. The mouse brain tissue samples were homogenized with HCl solution (0.01 mol/L), protein precipitated with methanol and centrifugation. For the untargeted method, one sample was derivatized with butanol (D0)-HCl and another sample was derivatized with deuterated butanol (D9)-HCl, then combined together and analyzed with UHPLC-MS. Chromatographic peak area ratio for each amino acid was then used for differential analyses between two samples. Results showed good accuracy with standard spiked samples (83.4–113.0 %). For the targeted quantitative method, the sample supernatants were dried and residues were derivatized with butanol (D0)-HCl. Internal standards of amino acids derivatized with deuterated butanol (D9)-HCl were added before analyzed with UHPLC-MS/MS. The intra- and inter-day precisions were in the intervals of 0.5–8.1 % and 0.3–9.1 %. The LOD and the LOQ were ranged from 0.03 × 10−3 to 0.92 × 10−3 µg mL−1 and 0.08 × 10−3 to 3.08 × 10−3 µg mL−1, respectively. Spiked recoveries were from 96.8 % to 111.7 %. Both methods were applied to analyze amino acids in brain tissue of C57BL/6 mice treated and untreated with piperine and the result showed that the levels of glutamic acid, aspartic acid, histidine, asparagine, γ-aminobutyric acid, alanine, leucine and isoleucine significantly decreased in the piperine treated group comparing with the untreated group.

Rice gluten meal as a substitute for soybean meal in the diets for growing rabbits

ABSTRACT The impacts of different dietary levels of rice gluten meal (RGM) on growth performance, digestibility, carcass characteristics, and blood traits of growing New Zealand White (NZW) rabbits were studied. One hundred and twenty, 6 weeks old weaned male rabbits (body weight; 682 [g] ± 23) were randomly allotted into four groups. The control diet contained 160 [g/kg] soybean meal (SBM), while the other three diets were obtained by replacing 40, 80, and 120 [g/kg] SBM with RGM (RGM40, RGM80, and RGM120, respectively). The results showed that RGM contained higher levels of dry matter (DM), crude protein (CP), ether extract (EE), ash, and gross energy than SBM. RGM contained a high level of arginine followed by leucine and valine as essential amino acids and high levels of glutamic, aspartic acid, and alanine as non-essential amino acids. The obtained results showed that the final body weight of rabbits fed diets containing 40, 80, and 120 [g/kg] RGM was higher than those fed the control diet. The daily weight gain of rabbits fed RGM diets increased (p < 0.05) by 10.50%, 6.50%, and 10.00%, respectively, compared to the control group. Rabbits fed RGM80 showed the highest (p < 0.05) digestibility of DM, organic matter (OM), EE, neutral detergent fibre (NDF), and acid detergent fibre (ADF) compared to the other tested levels. Rabbits fed RGM120 had the highest (p < 0.05) digestible energy (DE) and digestible crude protein (DCP) values. RGM inclusion levels of 40 and 80 [g/kg] increased (p < 0.05) plasma total protein and albumin compared to the control group. Rabbits fed a diet containing RGM40 had the highest (p < 0.05) globulin level. The highest (p < 0.05) plasma urea concentration level was measured in the rabbit group fed the RGM120 diet. Conclusively, RGM could be a valuable ingredient for growing rabbits, as at all the tested levels improved growth performance, digestibility, and nutritional values.

Radiocarbon Flux Measurements Reveal Mechanistic Insight into Heat-Stress Induction of Nicotine Biosynthesis in Nicotiana attenuata.

The effect of high-temperature (HT) stress on nicotine biosynthesis in Nicotiana attenuata was examined. Nicotine content was measured in mature leaves, young sink leaves, and in roots from well-watered plants grown at 25 °C as controls and from plants exposed to 38 °C and 43 °C temperatures applied for 24, 48, 72, and 96 h duration. At 38 °C, all leaf nicotine levels were significantly less than control plants for up to 72 h exposure but rose sharply thereafter to levels significantly greater than controls with 96 h exposure. In contrast, plants exposed to 43 °C never exhibited a reduction in leaf nicotine content and showed an increase in content with just 48 h exposure. Using radioactive 11CO2 and 13NO3-, we found that HT stress reduced both CO2 fixation and nitrate uptake. Furthermore, radiocarbon flux analysis revealed that 'new' carbon partitioning (as 11C) into the 11C-radiolabeled amino acid (AA) pool was significantly reduced with HT stress as were yields of [11C]-aspartic acid, an important AA in nicotine biosynthesis, and its beta-amido counterpart [11C]-asparagine. In contrast, [12C]-aspartic acid levels appeared unaffected at 38 °C but were elevated at 43 °C relative to controls. [12C]-Asparagine levels were noted to be elevated at both stress temperatures. Since HT reductions in carbon input and nitrogen uptake were noted to impede de novo AA biosynthesis, protein degradation at HT was examined as a source of AAs. Here, leaf total soluble protein (TSP) content was reduced 39% with long exposures to both stress temperatures. However, Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) which was 41% TSP appeared unaffected. Altogether, these results support the theory that plant proteins other than Rubisco degrade at elevated temperatures freeing up essential AAs in support of nicotine biosynthesis.

Predictive Ability of Serum Amino Acid Levels to Differentiate Fibromyalgia Patients from Healthy Subjects.

Fibromyalgia is a complex illness to diagnose and treat. To evaluate a broad range of circulating free amino acid (AA) levels in fibromyalgia patients as well as the ability of the AAs to differentiate fibromyalgia patients from healthy subjects. We carried out a case-control study to evaluate AA levels in 62 patients with fibromyalgia and 78 healthy subjects. This study adheres to the STROBE guidelines. AAs content was assayed by HPLC in serum samples. The predictive value of AA levels in fibromyalgia was determined by receiver operating characteristic (ROC) curve and forward binary logistic regression analyses. Fibromyalgia patients showed higher serum levels of aspartic acid, glutamic acid, aminoadipic acid, asparagine, histidine, 3-methyl-histidine, 5-methyl-histidine, glycine, threonine, taurine, tyrosine, valine, methionine, isoleucine, phenylalanine, leucine, ornithine, lysine, branched chain AAs (BCAAs), large neutral AAs, essential AAs (EAAs), non-essential AAs (NEAAs), basic AAs, EAAs/NEAAs ratio, phenylalanine/tyrosine ratio, and global arginine bioavailability ratio than the controls. Serum alanine levels were lower in patients than in controls. According to ROC analysis, most of these AAs may be good markers for differentiating individuals with fibromyalgia from healthy subjects. Results of logistic regression showed that the combination of glutamic acid, histidine, and alanine had the greatest predictive ability to diagnose fibromyalgia. Our results show an imbalance in serum levels of most AAs in patients with fibromyalgia, which suggest a metabolic disturbance. The determination of serum levels of these AAs may aid in the diagnosis of fibromyalgia, in combination with clinical data of the patient.

Exploring characteristics of placental transcriptome and cord serum metabolome associated with low birth weight in Kele pigs.

The neonate with low birth weight (LBW) resulted from intrauterine growth retardation (IUGR) exists a substantial risk of postpartum death. Placental insufficiency is responsible for inadequate fetal growth; however, the pathological mechanisms of placental dysfunction-induced IUGR in pigsremain unclear. In this study, the characteristics of placental morphology, placental transcriptome, and cord serum metabolome were explored between the Kele piglets with LBW and the ones with normal birth weight (NBW). Results showed that LBW was a common occurrence in Kele piglets. The LBW placentas showed inferior villus development and lower villi density compared to NBW placentas. There were 1024 differentially expressed genes (DEGs) identified by transcriptome analysis between the LBW and NBW placentas, of which 218 and 806 genes were up- and down-regulated in the LBW placentas, respectively. PPI network analysis showed that ITGB2, CD4, IL6, ITGB3, LCK, RAC2, CD8A, JAK3, TYROBP, and CXCR4 were hub genes in all DEGs. From GO and KEGG enrichment analysis, DEGs were primarily enriched in immunological response, cell adhesion, immune response, cytokine-cytokine receptor interaction, and PI3K-Akt signaling pathway. By using metabolomic analysis, a total of 115 differential metabolites in the cord serum of LBW and NBW piglets were found, mostly linked to amino acid metabolism and sphingolipid metabolism. In comparison to NBW piglets, LBW piglets had lower levels of arginine, isoleucine, and aspartic acid in the cord. Taken together, these data revealed dysplasia of the placental villus, insufficient supply of nutrients, and abnormal immune function of the placenta may be associated with the occurrence and development of LBW in Kele pigs.

Diagnostic value of serum neuroactive substances in the acute exacerbation of chronic obstructive pulmonary disease complicated with depression.

We aimed to investigate the potential diagnostic value of five serum neuroactive substances in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated with depression. A total of 103 patients with AECOPD were enrolled between August 2020 and August 2021. All patients were assessed using a self-rating depression scale and divided into AECOPD with or without depression groups. Baseline data and serum neuroactive substance levels were compared between the two groups. Logistic regression was used to identify the risk factors. The diagnostic performance of neuroactive substances was evaluated using receiver operating characteristic (ROC) curves. Patients with AECOPD complicated with depression exhibited higher partial pressure of CO2 values and higher chronic obstructive pulmonary disease assessment test (CAT) scores. An elevated proportion of patients with more than two acute exacerbations (AEs) in the previous year was observed in this patient group (all P < 0.001). The CAT score and number of AEs during the previous year were identified as independent risk factors for AECOPD complicated with depression. No significant differences were observed in the levels of aspartic acid and glutamate between the two groups (P > 0.05). Serum γ-aminobutyric acid (GABA) and glycine (Gly) levels were decreased. In contrast, serum nitric oxide (NO) levels were increased in the AECOPD complicated with the depression group (P < 0.05). Serum GABA and Gly levels exhibited a negative correlation, and NO levels positively correlated with the number of AEs in the previous year and the CAT score. The area under the ROC curve values for GABA, Gly, and NO were 0.755, 0.695, and 0.724, respectively. Serum GABA exhibited a sensitivity of 85.1% and a specificity of 58.9%, below the cut-off value of 4855.98 nmol/L. Serum GABA, Gly, and NO may represent potential biomarkers for AECOPD complicated with depression.

Serum amino acid profiling in differentiating clinical outcomes of multiple sclerosis.

Amino acid metabolism is crucial for regulating immune responses and can be monitored in blood serum samples. This study aimed to analyse serum amino acid profiles in people with multiple sclerosis (pwMS), taking into account differences depending on the disease outcomes. Serum amino acid profiling is a promising, reproducible and minimally invasive technology, available at different stages of the disease, enabling the search for a specific biomarker to differentiate MS clinical outcomes. The serum concentrations of 29 amino acids were determined using high-performance liquid chromatography mass spectrometry. A total of 121 pwMS (41 relapsing-remitting MS-RRMS; 55 secondary progressive MS - SPMS; and 25 primary progressive MS-RRMS) with a median Expanded Disability Status Scale (EDSS) score of 6 and 53 healthy controls (HCs) were included. We found significantly higher serum total amino acids concentrations in pwMS compared to HCs. Serum concentrations of arginine, 1-methyl-L-histidine and proline were higher in pwMS, while circulating citrulline, α-aminobutyric acid and tryptophan were lower in pwMS. We observed significant differences in serum total amino acids concentrations depending on MS type, with the highest level in the PPMS group and the lowest in the RRMS group. We found significantly higher serum levels of beta-aminoisobutyric acid in PPMS patients compared to those with RRMS and SPMS, and significantly higher serum levels of aspartic acid in PPMS patients compared to RRMS patients. From visual inspection, no trend was observed in total amino acids concentration with respect to the EDSS score. When analysing serum total amino acids concentration in pwMS with EDSS ≤ 5 compared to those with EDSS > 5, no significant differences were found. Amino acid metabolism is altered in pwMS and depends on the clinical type of the disease. Further studies are needed to determine whether serum metabolomic profiling of amino acids may have an application in the search for clinical phenotype-specific MS biomarkers.

Comparison of Amino Acid Profile, ACE Inhibitory Activity, and Organic Acid Profile of Cow and Goat Yogurts Produced with Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12, and Classical Yogurt Culture.

In this study, we aimed to produce a standard, more functional, and nutritious yogurt by using 5 different combinations of cow milk and goat milk and 2 types of starter cultures (classical yogurt culture and commercial probiotic culture). It was determined that the use of different milk types and different starter cultures in yogurt production had a statistically very significant effect (P < 0.01) on all physicochemical, microbiological, and biochemical properties. In addition, the storage period was effective on all parameters examined at varying rates. In the context, the use of goat milk in the experimental yogurt samples caused an increase in the ACE inhibitory activity values and the count of S. thermophilus, while the use of cow milk caused an increase in serum separation and pH values. On the other hand, serum separation, pH values, and ACE inhibitory activity and phenylalanine and leucine levels were found to be higher in the yogurts produced by using ABT-2 probiotic culture. It was observed that an increase in the levels of asparagine, aspartic acid, proline, and serine, as well as lactic acid, orotic acid, and citric acid, is higher in the yogurts produced by using classical yogurt culture. It has been concluded that the combination of goat milk and cow milk at different proportions and the use of probiotic culture together in yogurt production can produce yogurt that is more functional and richer in terms of organic compounds and essential amino acids.

Severe Obesity in Women Can Lead to Worse Memory Function and Iron Dyshomeostasis Compared to Lower Grade Obesity

Obesity is one of the modifiable risk factors for dementia. Insulin resistance, the abundance of advanced glycated end-products, and inflammation are some of the mechanisms associated with the lower cognitive performance observed in obesity. This study aims to evaluate the cognitive function of subjects with distinct degrees of obesity, comparing class I and II obesity (OBI/II) to class III obesity (OBIII), and to investigate metabolic markers that can distinguish OBIII from OBI/II. Study Design. This is a cross-sectional study, in which 45 females with BMI varying from 32.8 to 51.9 kg/m2 completed a set of 4 cognitive tests (verbal paired-associate test, stroop color, digit span, and Toulouse-Pieron cancellation test) and their plasma metabolites, enzymes, and hormones related to glycemia, dyslipidemia, and liver function, as well as the biomarkers of iron status, were concomitantly analyzed. OBIII showed lower scores in the verbal paired-associate test compared to OBI/II. In other cognitive tests, both groups showed similar performance. OBIII presented a lower iron status compared to OBI/II based on total iron binding capacity, degree of transferrin saturation, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin. The levels of indicators for glycemia, liver function, and lipid metabolism were similar in both groups. Analysis of plasma metabolites showed that OBIII had lower levels of pyroglutamic acid, myoinositol, and aspartic acid and higher levels of D-ribose than OBI/II. Iron is an essential micronutrient for several metabolic pathways. Thus, iron dyshomeostasis observed in severe obesity may aggravate the cognitive impairment by altering metabolic homeostasis and enhancing oxidative stress. These findings can contribute to searching for biomarkers that indicate cognitive performance in the population with obesity.

Metabolomic profiles in night shift workers: A cross-sectional study on hospital female nurses.

Shift work, especially including night shifts, has been found associated with several diseases, including obesity, diabetes, cancers, and cardiovascular, mental, gastrointestinal and sleep disorders. Metabolomics (an omics-based methodology) may shed light on early biological alterations underlying these associations. We thus aimed to evaluate the effect of night shift work (NSW) on serum metabolites in a sample of hospital female nurses. We recruited 46 nurses currently working in NSW in Milan (Italy), matched to 51 colleagues not employed in night shifts. Participants filled in a questionnaire on demographics, lifestyle habits, personal and family health history and work, and donated a blood sample. The metabolome was evaluated through a validated targeted approach measuring 188 metabolites. Only metabolites with at least 50% observations above the detection limit were considered, after standardization and log-transformation. Associations between each metabolite and NSW were assessed applying Tobit regression models and Random Forest, a machine-learning algorithm. When comparing current vs. never night shifters, we observed lower levels of 21 glycerophospholipids and 6 sphingolipids, and higher levels of serotonin (+171.0%, 95%CI: 49.1-392.7), aspartic acid (+155.8%, 95%CI: 40.8-364.7), and taurine (+182.1%, 95%CI: 67.6-374.9). The latter was higher in former vs. never night shifters too (+208.8%, 95%CI: 69.2-463.3). Tobit regression comparing ever (i.e., current + former) and never night shifters returned similar results. Years worked in night shifts did not seem to affect metabolite levels. The Random-Forest algorithm confirmed taurine and aspartic acid among the most important variables in discriminating current vs. never night shifters. This study, although based on a small sample size, shows altered levels of some metabolites in night shift workers. If confirmed, our results may shed light on early biological alterations that might be related to adverse health effects of NSW.

Blood metabolites in preterm infants with retinopathy of prematurity based on tandem mass spectrometry: a preliminary study

To study new biomarkers for the early diagnosis of retinopathy of prematurity (ROP) by analyzing the differences in blood metabolites based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and metabolomics. Dried blood spots were collected from 21 infants with ROP (ROP group) and 21 infants without ROP (non-ROP group) who were hospitalized in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2016. LC-MS/MS was used to measure the metabolites, and orthogonal partial least squares-discriminant analysis was used to search for differentially expressed metabolites and biomarkers. There was a significant difference in blood metabolic profiles between the ROP and non-ROP groups. The pattern recognition analysis, Score-plot, and weight analysis obtained 10 amino acids with a relatively large difference. Further statistical analysis showed that the ROP group had significant increases in blood levels of glutamic acid, leucine, aspartic acid, ornithine, and glycine compared with the non-ROP group (P<0.05). The receiver operating characteristic curve analysis showed that glutamic acid and ornithine had the highest value in diagnosing ROP. Blood metabolites in preterm infants with ROP are different from those without ROP. Glutamic acid and ornithine are the metabolic markers for diagnosing ROP. LC-MS/MS combined with metabolomics analysis has a potential application value in the early identification and diagnosis of ROP.

The relationship between islet β-cell function and metabolomics in overweight patients with Type 2 diabetes.

A cross-sectional study was performed using metabolomics in overweight patients with Type 2 diabetes (T2D) at different stages of the disease. We aimed to identify potential metabolites for assessing islet β-cell function in order to investigate the correlation between islet β-cell dysfunction and metabolite changes in overweight patients with T2D. We selected 60 overweight adults (24 ≤ body mass index [BMI] < 28 kg/m2) with T2D who had been admitted to our hospital. The participants were equally divided into three groups according to disease duration: H1 (duration ≤ 5 years), H2 (5 years < duration ≤ 10 years), and H3 (duration > 10 years). Questionnaires, physical examinations, laboratory tests, and imaging studies were administered to all participants. The modified homeostasis model of assessment (HOMA) index was calculated using fasting C-peptide levels, and metabolite assays were performed using mass spectrometry. The results showed that HOMA-β and visceral fat area (VFA) were negatively correlated with diabetes duration. The VFA was positively correlated with arginine, cysteine, methionine, proline, and succinyl/methylmalonylcarnitine levels. The HOMA-β was negatively correlated with the serine and tetradecanoyldiacylcarnitine levels, and positively correlated with the aspartic acid, cysteine, homocysteine, piperamide, proline, and valine levels. The HOMA-IR was negatively correlated with hydroxypalmitoylcarnitine levels and positively correlated with the myristoylcarnitine levels. Thus, at different stages of T2D progression in overweight patients, serine, aspartic acid, cysteine, homocysteine, piperamide, proline, valine, and tetradecanoyldiacylcarnitine may be associated with HOMA-β and represent potential novel biomarkers for evaluating islet β-cell function.

The Utility of Amino Acid Metabolites in the Diagnosis of Major Depressive Disorder and Correlations with Depression Severity.

Major depressive disorder (MDD) is a highly prevalent and disabling condition with a high disease burden. There are currently no validated biomarkers for the diagnosis and treatment of MDD. This study assessed serum amino acid metabolite changes between MDD patients and healthy controls (HCs) and their association with disease severity and diagnostic utility. In total, 70 MDD patients and 70 HCs matched in age, gender, and ethnicity were recruited for the study. For amino acid profiling, serum samples were analysed and quantified by liquid chromatography-mass spectrometry (LC-MS). Receiver-operating characteristic (ROC) curves were used to classify putative candidate biomarkers. MDD patients had significantly higher serum levels of glutamic acid, aspartic acid and glycine but lower levels of 3-Hydroxykynurenine; glutamic acid and phenylalanine levels also correlated with depression severity. Combining these four metabolites allowed for accurate discrimination of MDD patients and HCs, with 65.7% of depressed patients and 62.9% of HCs correctly classified. Glutamic acid, aspartic acid, glycine and 3-Hydroxykynurenine may serve as potential diagnostic biomarkers, whereas glutamic acid and phenylalanine may be markers for depression severity. To elucidate the association between these indicators and clinical features, it is necessary to conduct additional studies with larger sample sizes that involve a spectrum of depressive symptomatology.