Tyrosine Levels Research Articles

Metabolic profiling disturbance of PM2.5 revealed by Raman spectroscopy and mass spectrometry-based nontargeted metabolomics.

Fine particulate matter (PM2.5) is an important risk factor affecting human health. Therefore, a quick method for finding metabolic targets in situ in ambient fine particulate matter is crucial. In this study, the impact of PM2.5 on human lung epithelial cells (A549) was investigated by Raman spectroscopy and mass spectrometry (MS)-based nontargeted metabolomics analysis. Raman detection indicated that exposure to PM2.5 reduced the levels of phenylalanine, tyrosine, and nucleotides. Metabolomics results not only demonstrated a significant decrease of the aforementioned metabolites but also added some important metabolite information that could not be detected by Raman spectroscopy. Our study demonstrated that Raman spectroscopy was an in situ, real-time, and rapid detection method for detecting metabolites, especially suitable for the assignment of phenylalanine/tyrosine and nucleotides, which play important roles in cellular growth. Moreover, the metabolic profiling changes observed upon PM2.5 treatment mainly involved phenylalanine, tyrosine metabolism, purine and pyrimidine metabolism, and energy metabolism, clearly demonstrating that PM2.5 can inhibit the synthesis of protein and DNA/RNA and reduce cellular energy supplies, further influencing cellular proliferation and other activities.

Antagonization of Ghrelin Suppresses Muscle Protein Deposition by Altering Gut Microbiota and Serum Amino Acid Composition in a Pig Model

Simple SummaryThis study investigated the effects of the antagonization of ghrelin on muscle protein deposition, eating patterns and gut microbiota in pigs by injecting ghrelin antagonist ([D-Lys3]-GHRP-6) in a short term. We found that the antagonization of ghrelin affected the eating patterns of animals, which resulted in changes in the absorption of amino acids and gut microbiota, and it reduced protein deposition in muscles. We emphasize the important role of ghrelin in promoting muscle protein deposition and provide new clues for future research on improving muscle loss.Ghrelin is an appetite-stimulating hormone that can increase food intake and has been reported to prevent muscle loss; however, the mechanism is not yet fully understood. In this study, [D-Lys3]-GHRP-6 (GHRP) was used to investigate the effects of the antagonization of ghrelin on muscle protein deposition, eating patterns and gut microbiota in a pig model. We found that the growth performance and muscle fiber cross-sectional area of pigs treated with GHRP were significantly reduced compared with the control (CON) group. Moreover, the levels of serum isoleucine, methionine, arginine and tyrosine in the GHRP group were lower than that of the CON group. The abundance of acetate-producing bacteria (Oscillospiraceae UCG-005, Parabacteroides and Oscillospiraceae NK4A214 group) and acetate concentration in the colons of pigs treated with GHRP were significantly reduced. In addition, the injection of GHRP down-regulated the mRNA expression of MCT-1 and mTOR, and it up-regulated the mRNA expression of HDAC1, FOXO1 and Beclin-1. In summary, the antagonization of ghrelin reduced the concentration of important signal molecules (Arg, Met and Ile) that activate the mTOR pathway, concurrently reduce the concentration of HDAC inhibitors (acetate), promote autophagy and finally reduce protein deposition in muscles.

The Relationship Between the Motor Lateralization and the Concentration of Cortisol and Tyrosine in Dogs Exposed to Stress During Veterinary Activities

ABSTRACT The aim of the study was to assess the relationship between the motor lateralization in dogs and the concentration of cortisol and tyrosine in their plasma during a visit to a veterinary clinic. The research group consisted of 56 dogs. Motor lateralization was tested by of an adhesive tape test. The stress intensity was assessed basing on the levels of cortisol and ft4 in the serum blood. The statistical analysis revealed that in the group of 56 dogs there were 14 left-pawed dogs, 36 right-pawed dogs, and 6 dogs did not show particular paw preference. The average cortisol levels in particular groups were as follows: 7.94 ug/dl, 3.92 ug/dl and 3.7 ug/dl, whereas the level of tyrosine in the subjects that demonstrated left-sided lateralization (mean ± SE) (1.95 ± 0.46 ng/dl) for those with right-side lateralization (1.56 ± 0.23 ng/dl) and ambilateral dogs (1.01 ± 0.22 ng/dl). The statistical calculation of Pearson’s χ2 showed a significant relationship between the sex and the lateralization (χ2 = 6.238, df = 2, p = 0.0442).

Plasma Levels and Renal Handling of Amino Acids Contribute to Determination of Risk of Mortality or Feed of Ventilation in Patients with COVID-19.

COVID-19 infection may lead to serious complications, e.g., need for mechanical ventilation or death in some cases. A retrospective analysis of patients referred to our COVID Emergency Department, indiscriminately, was performed. A routine lab analysis measured amino acids in plasma and urine of patients. Data of surviving and deceased patients and those requiring or not requiring mechanical ventilation were compared, and logistic regression analyses have been performed. Deceased patients were older, had higher blood glucose, potassium, AST, LDH, troponin, d-dimer, hsCRP, procalcitonin, interleukin-6 levels (p < 0.05 for all). They had lower plasma serine, glycine, threonine, tryptophan levels (p < 0.01), higher tyrosine and phenylalanine levels (p < 0.05), and higher fractional excretion of arginine, methionine, and proline (p < 0.05) than survivors. In a regression model, age, severity score of COVID-pneumonia, plasma levels of threonine and phenylalanine were predictors of in-hospital mortality. There was a difference in ventilated vs. non-ventilated patients in CT-scores, glucose, and renal function (p < 0.001). Using logistic regression, CT-score, troponin, plasma level, and fractional excretion of glycine were predictors of ventilation. Plasma levels and renal excretion of certain amino acids are associated with the outcome of COVID-19 infection beside other parameters such as the CT-score or age.

Mendelian Randomization Analysis Identifies Blood Tyrosine Levels as a Biomarker of Non-Alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) is a complex disease associated with premature mortality. Its diagnosis is challenging, and the identification of biomarkers causally influenced by NAFLD may be clinically useful. We aimed at identifying blood metabolites causally impacted by NAFLD using two-sample Mendelian randomization (MR) with validation in a population-based biobank. Our instrument for genetically predicted NAFLD included all independent genetic variants from a recent genome-wide association study. The outcomes included 123 blood metabolites from 24,925 individuals. After correction for multiple testing, a positive effect of NAFLD on plasma tyrosine levels but not on other metabolites was identified. This association was consistent across MR methods and was robust to outliers and pleiotropy. In observational analyses performed in the Estonian Biobank (10,809 individuals including 359 patients with NAFLD), after multivariable adjustment, tyrosine levels were positively associated with the presence of NAFLD (odds ratio per 1 SD increment = 1.23 [95% confidence interval = 1.12–1.36], p = 2.19 × 10−5). In a small proof-of-concept study on bariatric surgery patients, blood tyrosine levels were higher in patients with NAFLD than without. This study revealed a potentially causal effect of NAFLD on blood tyrosine levels, suggesting it may represent a new biomarker of NAFLD.

Diagnosing Metabolic Diseases Using Thin Layer Chromatography: Laboratory Experiment for both Organic Chemistry and Biochemistry Undergraduate Laboratories

With the ability to resolve metabolites as well as proteins, Thin Layer Chromatography (TLC) is a technique that is used in both Organic Chemistry as well as Biochemistry classes. There were two goals of this project: first was to develop a virtual laboratory experience for students in Organic Chemistry lab that expanded upon a previous experiment with TLC. The second was a project in method development for Biochemistry students. Students in Organic Chemistry lab had previously completed an experiment in TLC that required identification of an analgesic by comparing Rf value to those of standards. This project produced a virtual one where students were expected to diagnose various diseases based on TLC of affected amino acids. The diseases involved were Phenylketonuria, ornithine transcarbamylase (OTC) deficiency, arginemia, tyrosinemia, maple syrup urine disease citrullinemia type I and type II which respectively resulted in increased levels of amino acids phenylalanine, ornithine, arginine, tyrosine, either leucine, isoleucine or valine, or citrulline. The procedure involved spotting the standards and “plasma from blood” samples on the TLC plate with 70/30 mixture of n‐propanol/water. Amino acids were visualized by staining with ninhydrin. Several of the relevant amino acids have Rf values that are similar. In order to correctly identify the disease, a second piece of information was needed: the relative level of urea. Four of the diseases are urea cycle disorders that produce decreased levels of urea while the other three have normal levels. Students were provided with a picture of a standard curve of urea as well as pictures of the patients; this was used to identify if the disease was a UCD or not. In order to assess learning, students were given a pre and post test assessment. Students had previously done a TLC and 73.8% were able to correctly identify the role of various components when given a copy of the procedure. There was a 5.8% increase in score in the post test. For questions that addressed the theory of how TLC works or other applications, 37.7% of students on pre test could answer correctly. This value increased to 55.0% on the post test; this result suggests were able to deepen their knowledge of TLC with a second exposure. Another approach was taken for the Biochemistry students. Method development has been shown to be a critical skill, yet it is difficult to teach. Biochemistry students were provided with “blood” of five types of patients (normal, arginemia, OTC deficiency, citrullinemia type I and II), basic procedure for separating amino acids on TLC, and the amounts of these amino acids normally found in blood as well as in the disease state. The question for these students was if it was possible to detect these diseases using TLC? Students were given a pre test assessment. The great majority (81.2%) were able to partially or completely identify the function of the components in TLC. Students were asked to list questions that must be addressed in order to answer this question when provided with blood or plasma. Student responses covered a wide range and addressed both valid questions (do the amino acids have different Rfvalues or is the amount of amino acid detectable in this method) as well as not valid questions to having no answers.

NMR based metabolic profiling of patients with potential celiac disease elucidating early biochemical changes of gluten-sensitivity: A pilot study

BackgroundThe patients with positive celiac disease (CeD) specific serology, but no evidence of intestinal inflammation are defined as potential celiac disease (PCeD) patients. About one-third of PCeD patients develop intestinal inflammation over time. The present study investigated the metabolome of small intestinal biopsies, blood plasma, and urine of patients with PCeD to understand the biochemical changes underlying the CeD. MethodsThe metabolic profiles of small intestinal biopsies, blood plasma, and urine of patients with PCeD (n = 7) were compared with CeD (n = 64) and controls (n = 15) [disease controls (DC) and healthy controls (HC)] using 1H NMR spectroscopy. ResultsThe intestinal mucosa of PCeD showed lower levels of histidine, glycine, tyrosine, and tryptophan compared to DC. Altered levels of 6 metabolites (glucose, acetate, acetoacetate, β-hydroxybutyrate, pyruvate, arginine) in blood plasma and two metabolites (succinate and aminohippurate) in urine were observed in PCeD compared to HC. The PLS-DA model built on the concentration of blood plasma showed separate clustering for PCeD and CeD patients. ConclusionAltered metabolic profile of PCeD suggested that gluten intolerance was evident at the metabolic level before the intestinal damage. Altered energy metabolism and lower cytoprotective activity (histidine, glycine, arginine) indicated vulnerability to develop intestinal inflammation in PCeD over time. Our study may provide an insight into early biochemical processes of the progression of PCeD to CeD.

Effect of dietary phenylalanine levels on growth, hemato-biochemical composition and tyrosine replacement value for phenylalanine in stinging catfish Heteropneustes fossilis –Bloch 1974 fingerling

Two 10-week feeding experiments were conducted to determine the total aromatic amino acid requirement and tyrosine (Tyr) replacement value for phenylalanine (Phe) for fingerling Heteropneustes fossilis by feeding casein + gelatin based amino acid test diets [400 g/kg crude protein (CP); 17.90 MJ/ kg gross energy (GE)]. In experiment 1, Phe was determined by feeding six test diets containing graded levels of Phe (4.5–14.5 g/kg diet, as fed) with 6.0 g/kg Tyr fixed and fed in triplicate groups of 20 fish each in 60-L troughs fitted with continuous flow-through. Significantly (P < 0.05) highest live weight gain (LWG%), best-feed conversion ratio (FCR), highest protein efficiency ratio (PER) and body protein deposition (BPD) was reported at 10.5 g/kg dietary Phe with constant level of Tyr 6.0 g/kg fed group. Quadratic regression analysis of live weight gain, FCR, PER and BPD data indicated Phe requirement at 11.08, 10.75, 10.45 and 10.45 g/kg of diet, respectively. Based on the above results, Phe requirement of H. fossilis is recommended at 10.8 g/kg of diet. A second experiment under similar experimental design was conducted containing graded levels of Tyr (2.1–12.1 g/kg diet, as fed) with 10.8 g/kg Phe fixed in all the diets to determine the replacement value of Tyr for Phe. Significantly (P < 0.05) highest LWG%, best-FCR, PER and BPD values were obtained at 8.1 g/kg dietary tyrosine level. Quadratic regression analysis of LWG%, FCR, PER and BPD data indicated Tyr requirement at 8.7, 8.7, 8.05 and 8.05 g/kg of diet, respectively. The above results suggest that 8.4 g/kg Tyr, corresponding to 21.0 g/kg of protein would be useful for optimum growth of H. fossilis at fingerling stage and the replacement value of Tyr for Phe is 43.75% on weight and 39.89% on molar basis. Thus, the total aromatic amino acid requirement was recommended to be 19.2 g/kg of diet, corresponding to 48.0 g/kg of protein for optimum growth of H. fossilis.

Plasma branched-chain and aromatic amino acids correlate with the gut microbiota and severity of Parkinson\u2019s disease

Disturbances of circulating amino acids have been demonstrated in patients with Parkinson’s disease (PD). However, there have been no consistent results for branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs), and related factors have not been explored. We aimed to explore plasma BCAA and AAA profiles in PD patients, and identify their correlations with clinical characteristics and the gut microbiota. Plasma BCAA (leucine, isoleucine, and valine) and AAA (tyrosine and phenylalanine) levels were measured in 106 PD patients and 114 controls. Fecal samples were collected from PD patients for microbiota sequencing and functional analysis. We found that plasma BCAAs and tyrosine were decreased in PD patients. BCAAs and AAAs were correlated with clinical characteristics and microbial taxa, and, in particular, they were negatively correlated with the Hoehn and Yahr stage. Compared with early PD patients, BCAA and AAA levels were even lower, and microbial composition was altered in advanced PD patients. Predictive functional analysis indicated that predicted genes numbers involved in BCAA biosynthesis were lower in advanced PD patients. What’s more, the fecal abundances of critical genes (ilvB, ilvC, ilvD, and ilvN) involved in BCAA biosynthesis were reduced and fecal BCAA concentrations were lower in advanced PD patients. In conclusion, the disturbances of plasma BCAAs and AAAs in PD patients may be related to the gut microbiota and exacerbated with PD severity. The microbial amino acid metabolism may serve as a potential mechanistic link.

Untargeted Plasma Metabolomics Reveals Extensive Metabolic Alterations Among Treatment-Naive Human Immunodeficiency Virus/Hepatitis C Virus Co-Infected Patients with Liver Disease Progression.

Both human immunodeficiency virus (HIV) and hepatitis C virus (HCV) may induce metabolic disorders and cause liver complications. Therefore, we aim to analyze the metabolite differences among treatment-naive HIV/HCV co-infected patients with versus without liver disease progression (LDP) and HIV mono-infected patients. A cross-sectional study was conducted in 65 HIV/HCV co-infected patients (22 with LDP and 43 without) and 65 HIV mono-infected patients in Dehong prefecture of Yunnan province, China. Plasma metabolomics were measured by gas chromatography-mass spectrometry (MS) and liquid chromatography-MS. Discrimination analysis, pathway enrichment analysis, generalized linear model with binomial distribution, and area under the receiver-operating characteristic curve (AUC) were conducted to identify bilateral differences in metabolites and pathways in different comparison groups. A total of 10,831 with 673 named and 10,158 unnamed metabolites were detected. Compared with HIV/HCV co-infected patients without LDP, phenylalanine, tyrosine, and tryptophan biosynthesis pathway with the increased level of tyrosine were significantly altered among HIV/HCV co-infected patients with LDP. Compared with HIV mono-infected patients, the decreased level of glutamine and increased levels of glutamic acid, arachidonic acid, and its derivatives were identified among HIV/HCV co-infected patients. Metabolite panels adjusted for baseline information had a higher accuracy than baseline model (without metabolite information) in distinguishing HIV/HCV co-infected patients with versus without LDP (AUC 0.951 vs. 0.849, p = .027) and HIV/HCV co-infected patients from HIV mono-infected patients (AUC 0.889 vs. 0.766, p < .001). A novel set of metabolites were found to discriminate HIV/HCV co-infected patients with versus without LDP, and from HIV mono-infected patients, which may have mechanistic and interventional implications.

Maternal Sodium p-Perfluorous Nonenoxybenzene Sulfonate Exposure Disturbed Lipid Metabolism and Induced an Imbalance in Tyrosine Metabolism in the F1 Generation of Mice.

The toxicity of perfluorinated compounds (PFCs) to mammals has recently received increasing attention. However, the effects of maternal sodium p-perfluorous nonenoxybenzene sulfonate (OBS) exposure during pregnancy and lactation on the liver function of dams (F0) and offspring (F1) mice are still unknown. The results demonstrated that maternal OBS treatment could not only induce lipid metabolism dysfunction but also disrupt amino acid metabolism in the liver of F0 and F1 generations. OBS had marked accumulation in the liver, and the serum and liver triglyceride (TG) levels increased in the F0 and F1 generations after maternal OBS exposure. Moreover, maternal OBS exposure changed the transcriptional levels of genes related to lipid metabolism (fatty acid (FA) synthesis, TG synthesis, and transport) and induced changes in the amino acid level in dams and 20-day-old mice offspring (F1-20 d). Additionally, the regulation of lipid metabolism by OBS was mainly dependent on the activation of peroxisome proliferator-activated receptor γ (PPARγ) and cluster of differentiation 36 (CD36). Interestingly, OBS could also disturb tyrosine (TYR) metabolism by increasing the TYR level and downregulating fumarate acetoacetate hydrolase (FAH). Together, these results indicated that the liver can be perceived as the major target tissue of OBS, which strongly affected metabolic function and ultimately led to an imbalance in the metabolism of lipids and TYR. In summary, maternal OBS exposure during pregnancy and lactation has toxic effects on the hepatic metabolism of dams and offspring, indicating that the toxic effects could obviously cross generations of mice, and we should pay more attention to understanding the health risk to both dams and offspring.

Fusobacterium nucleatum Affects Cell Apoptosis by Regulating Intestinal Flora and Metabolites to Promote the Development of Colorectal Cancer.

Background/AimsIntestinal flora, especially Fusobacterium nucleatum (Fn), can affect the development of colorectal cancer (CRC). In this study, we examined the composition of intestinal flora and their metabolites in the tissues, serum and feces of CRC patients.Materials and MethodsCRC tissues, adjacent normal colonic tissues, fecal and serum samples were collected from CRC patients who received surgical treatment between January 2018 and January 2020. Fecal and serum samples were collected from healthy individuals for comparison. In addition, fecal samples were collected from BALB/c female mice. SW480, a human CRC cell line, was utilized for in vitro studies. The experiments involved 1H-NMR-based metabolomics analysis, targeted and untargeted mass spectrometry analysis, and intestinal flora 16S rDNA V4 region sequencing.ResultsThe abundance of Bacteroides and propionic acid concentration were decreased and that of Lactobacillus and lactic acid concentration were increased in CRC tissues. In addition, the abundances of Ruminococcus, Prevotella, and Sutterell were decreased in CRC patients. The levels of leucine and isoleucine were decreased in the serum and tumor tissues of CRC patients. Aspartate, glutamate and glutathione levels were elevated in the tissues of CRC patients only. The serum glutamine, tyrosine, valine, alanine, and histidine levels were decreased significantly. Lactic acid inhibited and propionic acid promoted apoptosis among SW480 CRC cells.ConclusionFn affected the apoptosis of CRC cells and promoted the progression of CRC by affecting the distribution of intestinal flora, which altered the concentrations of metabolites such as lactic acid, propionic acid. Intestinal flora could regulate amino acid metabolism.

Exposure to low-dose cadmium induces testicular ferroptosis

As an environmental pollutant, cadmium (Cd) has been widely reported to induce male infertility due to its gonadotoxicity. However, the specific mechanism of Cd-induced testicular damage remains unclear. We investigated whether Cd causes testicular injury through ferroptosis. Male C57BL/6 J mice were exposed to 0, 0.5, or 5 ppm Cd via drinking water, starting in utero, and continuing through 24 weeks post-weaning. The results showed that Cd accumulated in the testes in a dose-dependent manner. Cd exposure at a concentration of 5 ppm, but not 0.5 ppm, caused a mass loss and detachment of germ cells, as well as a decreased meiotic index and testis weight. Exposure to 5 ppm Cd caused iron accumulation, increased levels of malondialdehyde (MDA) and nitro tyrosine (3-NT), and decreased expression of Nrf2, HO-1 and SOD2. We also found that exposure to 5 ppm Cd significantly decreased the expression of SLC7A11, a marker of ferroptosis in mice, along with the expression of SLC40A1 mRNA and ferritin heavy chain (FTH) protein, whereas there was no obvious change in the mRNA expression of Tfrc, ZIP8, ZIP14, and NCOA4. These findings indicate that 5 ppm Cd exposure increased testicular ferroptosis, which may be attributed to the reduction of stored iron export.

Alterations in the metabolic status of amino acids in newborns of pre-eclampsia women.

Changes in amino acid (AA) levels have been observed in women with pre-eclampsia, but data on their newborns are scarce. This study aimed to evaluate 11 AAs in newborns of 378 PE and 18,666 non-PE pregnant women. We found that the levels of alanine, arginine, glycine, methionine, phenylalanine, valine, and leucine/isoleucine/hydroxyproline in newborns of PE women were significantly higher than those of non-PE women, whereas the level of tyrosine was lower. This different metabolic status deserves further study to determine whether this pattern persists or is likely to increase the risk of future diseases in these newborns.

Fluctuations in Metabolites and Bone Markers Across the Menstrual Cycle in Eumenorrheic Women and Oral Contraceptive Users.

Little is known about changes in circulating metabolites during the menstrual cycle and how use of oral contraceptives (OCs) affects these changes. To study fluctuations in circulating metabolite and bone marker levels during the menstrual/pill cycle in eumenorrheic women and OC users. Plasma samples were collected from 28 eumenorrheic women and 10 OC users at 7 to 9 time points across a menstrual/pill cycle. Longitudinal and cross-sectional analyses were performed to examine the cycle- and OC-induced variations in the plasma metabolite and bone turnover marker levels. In eumenorrheic women, plasma levels of alanine, glutamine, threonine, and tyrosine varied significantly across the menstrual cycle, and all dropped to the lowest level around day 21 of the menstrual cycle. These amino acid concentrations were negatively correlated with fluctuations in progesterone and/or estrogen levels. A between-group analysis showed that plasma levels of alanine, glutamine, glycine, proline, and tyrosine were lower in OC users than in nonusers. Concomitantly, plasma C-terminal telopeptide of type I collagen (CTX) and N-terminal propeptide of type I procollagen (PINP) levels were lower in OC users. Intriguingly, when all data were pooled, variations in CTX and PINP levels were positively correlated with fluctuations in proline and glycine concentrations (r > 0.5 or 0.3 < r < 0.5, P < 0.05). The menstrual cycle and the use of OCs alter plasma levels of metabolites and bone turnover markers in young women. While the impact of these findings remains to be established, the lower glycine level among OC users and the accompanying lower CTX level supports that the use of OCs lowers collagen turnover in young women and may thereby have long-term implications for bone health among OC users.

Proximate composition and amino acid profile of European eel skin: influence of body weight

Fish processing industries worldwide are discarding million kilograms of fish waste per year. The disposal of these wastes is an important handicap in fish processing industry. The thick eel skin is considered a waste product in the fish processing industry and in the home and is usually converted into low market-value products. The aims of this study were to evaluate the variations in the general chemical composition and amino acid content of eel skin in relation to body weight. The moisture content decreased and the lipid content increased with the weight of the eels. Eel skin had a high protein content, which did not vary significantly with eel weight. Glycine was the most abundant amino acid. The predominant essential amino acid was leucine. The smaller eels contained higher levels of threonine, valine, isoleucine, leucine, lysine, glutamic acid and tyrosine than the other groups. The larger eels contained higher levels of methionine, hydroxyproline, glycine, arginine, alanine and proline than the other groups. The protein indices showed that the skin from smaller eels was of higher nutritional quality.Graphical abstract

Longitudinal Serum Metabolomics in Extremely Premature Infants: Relationships With Gestational Age, Nutrition, and Morbidities.

An increasing number of extremely premature infants survive the neonatal period and beyond. Little is known about the maturation of the preterm infant’s metabolome and its relation to the development of morbidities. Using 1H-NMR, we investigated the serum metabolic profile of 87 infants born at a gestational age (GA) <28 weeks [mean GA (SD) 25.4 (1.4) weeks] in samples longitudinally collected from birth to term equivalent age. The infant metabolome was analyzed in relation to GA, postnatal age, nutrition, and preterm morbidities. At postnatal day 1, low GA correlated with high levels of 3-hydroxyisobutyrate, acetate, acetoacetate, acetone, formate, glucose, and valine. Nearly all quantified metabolites displayed postnatal concentration changes. For example, the two phospholipid-related metabolites myo-inositol and ethanolamine displayed a similar decline from birth over the first weeks of life, irrespectively of GA. The proportion of enteral/parenteral energy intake in the first 28 days significantly correlated with mean levels of 52% of the analyzed metabolites. Low enteral energy intake was associated with high serum levels of 3-hydroxyisobutyrate, creatinine, glucose, glycerol, histidine, lactate, leucine, lysine, methionine, ornithine, phenylalanine, proline, threonine, and uridine. There were also significant correlations between high enteral intake and high serum levels of isoleucine and tyrosine. Retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) outcomes were not significantly associated with metabolite levels in the neonatal period after correcting for multiple testing. In conclusion, the serum metabolome of extremely premature infants changes substantially in the neonatal period, largely driven by the gradual transfer from total parenteral nutrition to full enteral feeding. Further studies are needed to disentangle the intricate relationships between the metabolome, nutritional management, GA, and the development of preterm morbidities.

CircCDK17 knockdown inhibits tumor progression and cell glycolysis by downregulaing YWHAZ expression through sponging miR-1294 in cervical cancer

BackgroundCervical cancer (CC) is the fourth aggressive tumor affecting women worldwide. Circular RNA (circRNA) is enrolled in CC process. This study aims to unveil the profiles of circ_101119 (circCDK17) in cell proliferation, migration, invasion, apoptosis and glycolysis in CC.MethodsThe expression levels of circCDK17, microRNA-1294 (miR-1294) and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) mRNA were detected by quantitative real time polymerase chain reaction (qRT-PCR). The protein expression levels of YWHAZ, recombinant glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) were determined by western blot. Cell proliferation, migratory and invasive abilities and apoptosis were illustrated by cell counting kit-8 (CCK-8) assay, transwell assay and flow cytometry analysis, respectively. Cell lactate production, glucose uptake and adenosine 5'-triphosphate (ATP) level were severally elucidated by lactate assay kit, glucose assay kit and ATP detection kit.ResultsCircCDK17 expression and the mRNA and protein expression levels of YWHAZ were dramatically upregulated, while miR-1294 expression was obviously downregulated in CC tissues or cells compared with control groups. CircCDK17 silencing suppressed cell proliferation, migration, invasion and glycolysis, and induced cell apoptosis in CC; however, miR-1294 inhibitor restrained these effects. Additionally, circCDK17 was a sponge of miR-1294 and miR-1294 bound to YWHAZ. Furthermore, circCDK17 knockdown inhibited tumor formation in vivo.ConclusionCircCDK17 knockdown repressed cell proliferation, migration, invasion and glycolysis, and promoted cell apoptosis via miR-1294/YWHAZ axis in CC. This finding provides a theoretical basis in studying circRNA-mediated therapy in CC.

Differentiation between sepsis survivors and sepsis non-survivors through blood serum metabolomics: A proton nuclear magnetic resonance spectroscopy (NMR) study

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is a subset of sepsis with underlying circulatory cellular and metabolic abnormalities associated with higher mortality rates. However, a detailed understanding of sepsis is still limited. The present study reports the differences in the metabolic profile of serum samples of patients with sepsis compared to healthy controls using Nuclear Magnetic Resonance (NMR) spectroscopy. The study also compares the NMR metabolomics on day zero of admission among sepsis survivors (those who survived till day seven) and sepsis non-survivors (those who succumbed on day zero). Furthermore, the different metabolites in serum were analysed by univariate and multivariate analysis, ROC analysis, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA) methods. Metabolites with VIP score (>1·0) were considered as potential biomarker/s to discriminate sepsis survivors from non- survivors at day zero. Data showed that phenylalanine was significantly higher in sepsis patients compared to healthy controls, whereas isoleucine, valine and histidine were significantly lower in sepsis patients compared to healthy controls. Also, non-survivors had higher serum levels of creatine, phosphocreatine, choline, betaine, tyrosine, histidine and phenylalanine concentrations than survivors. These findings suggest that the metabolic alterations at day zero may predict the survival of patients with sepsis. The significant differences seen in metabolites concentration of amino acids, phospholipids and creatine may be used as early prognostic markers to discriminate non-survivors from survivors of sepsis patients at day zero. Our findings indicate that the metabolite alterations are associated with the progression of the disease.

A culture model for the assessment of phenylalanine neurotoxicity in phenylketonuria

ObjectivePhenylketonuria (PKU) is caused by a specific mutation of the phenylalanine hydroxylase (PAH) gene. The deficiency of PAH results in high phenylalanine levels (Phe), low tyrosine levels (Tyr), and reduced catecholamine neurotransmitters. The majority of PKU patients, if untreated, develop severe mental retardation. The specific contribution of high Phe and low Tyr levels in mental retardation is largely unknown. In this study, we used organic hippocampal slice cultures in an optimized medium as an adequate culture model to decipher the precise role of high Phe and low Tyr levels on synaptic and glial integrity in PKU. The hippocampus is closely related to learning and memory and reduced catecholamine neurotransmitter levels can be neglected since these neurotransmitters do not derive from the hippocampus. Cultures exposed to physiological concentrations of Phe were compared with cultures exposed to doses of Phe/Tyr, as in the cerebral fluid of PKU patients.MethodsUsing capillary western blot analysis and immunohistochemistry, followed by quantitative image analysis, we tested the expression of various pre- and postsynaptic proteins (PSD95, synaptopodin, SNAP25, synaptophysin), glial cell markers (GFAP, Iba1, P2Y12, CD68, C3b), and the morphology of glial cells.ResultsWe found a downregulation of the postsynaptic protein PSD95 and the presynaptic protein SNAP25 in the presence of high/low Phe/Tyr levels after 3 weeks, which, then however, recovered after 6 weeks in culture. Furthermore, no change in the expression pattern of glial proteins was observed.ConclusionOur results show that high Phe levels/low Tyr levels alone are unlikely to substantially contribute to mental retardation in PKU. The direct neurotoxic potency of high Phe/low Tyr concentrations is almost negligible since the effects are transient. The transient character in the presence of unchanged levels of high Phe/low Tyr points to a role of reduced catecholamine derivate neurotransmitters, rather than of high Phe/low Tyr levels in PKU.