Tyrosine Levels Research Articles

Increase in IAA levels by EPSPS copy number variation relates to fitness advantage in Eleusine indica.

Long-term use of chemical weed control has led to some weedy species evolving herbicide resistance traits with fitness advantage. Our previous studies revealed glyphosate resistance in an Eleusine indica population due to copy number variation of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) comes with fitness advantage under non-competitive conditions. Here, transcriptomics and targeted metabolomics were used to investigate physiological basis associated with the fitness advantage. Relative copy number of EPSPS gene and plant dry weight of the glyphosate-resistant (R) population was 88.3- and 1.2- times, respectively, higher than that in the wild type (WT) plants that were isolated from within the R population. Seven genes were screened to be relevant to fitness growth trait by RNA-seq. The level of aromatic amino acids Tryptophan (Trp), Phenylalanine (Phe) and Tyrosine (Tyr), products in the shikimate pathway catalyzed by EPSPS, was 1.2-times higher in R compared to the WT plants. The metabolites associated with Trp metabolism indole-3-acetic acid (IAA), 3-indolepropionic acid (IPA), indole-3-acetamide (IAM) in the R plants were 2.0-, 1.8- and 1.4- times higher than that in the WT plants, respectively. All the results indicate that fitness advantage in the studied R E. indica population may be caused by higher IAA production due to over-expression of the EPSPS gene and pleiotropically by elevated carbon metabolism. The findings in this research can provide reference information for control strategies to the glyphosate-resistant E. indica. © 2025 Society of Chemical Industry.

Fucoidan alleviated colitis aggravated by fiber deficiency through protecting the gut barrier, suppressing the MAPK/NF-κB pathway, and modulating gut microbiota and metabolites

Insufficient dietary fiber intake has become a global public health issue, affecting the development and management of various diseases, including intestinal diseases and obesity. This study showed that dietary fiber deficiency enhanced the susceptibility of mice to colitis, which could be attributed to the disruption of the gut barrier integrity, activation of the NF-κB pathway, and oxidative stress. Undaria pinnatifida fucoidan (UPF) alleviated colitis symptoms in mice that fed with a fiber deficient diet (FD), characterized by increased weight gain and reduced disease activity index, liver and spleen indexes, and histological score. The protective effect of UPF against FD-exacerbated colitis can be attributed to the alleviation of oxidative stress, the preservation of the gut barrier integrity, and inhibition of the MAPK/NF-κB pathway. UPF ameliorated the gut microbiota composition, leading to increased microbiota richness, as well as increased levels of Muribaculaceae, Lactobacillaceae, and Bifidobacterium and reduced levels of Proteobacteria, Bacteroidetes, and Bacteroides. Metabolomics analysis revealed that UPF improved the profile of microbiota metabolites, with increased levels of carnitine and taurine and decreased levels of tyrosine and deoxycholic acid. This study suggests that UPF has the potential to be developed as a novel prebiotic agent to enhance human health.

Dynamic responses and adsorption mechanisms of Chlamydomonas reinhardtii extracellular polymeric substances under Cd, Cu, Pb, and Zn exposure.

Extracellular polymeric substances (EPS) can effectively attenuate heavy metal mobility in aquatic ecosystems and reduce metal toxicity to cells. However, a systematic study of microalgae EPS responses and their adsorption behaviors, characteristics, and mechanisms under different heavy metal exposures has not been performed. In this study, EPS extracted from Chlamydomonas reinhardtii CC-125 was analyzed for compositional changes (monosaccharides and proteins) under Cd, Cu, Pb, and Zn treatments. The EPS adsorption capacities and mechanisms for the four metal ions were also investigated. Cd (10 mg/L), Cu (5 mg/L), and Zn (5 mg/L) exposure induced changes in the microalgal EPS composition and structure, and a protein/polysaccharide ratio of greater than 1 was found. This result indicated the crucial role of proteins in stress resistance. In contrast, Pb stress resulted in an increase of 532.64% and 117.48% in proteins and polysaccharides, respectively, with galactose and glucose playing key roles in this process. A fluorescence analysis revealed that Cd/Pb exposure reduced the tryptophan and tyrosine levels in the EPS, while Cu/Zn only weakened tryptophan. As a biosorbent, the adsorption capacity of the EPS for the four metals followed the order of Pb > Cd > Cu > Zn. The fluorescence quenching titration results revealed that fluorescent compounds in the EPS had the strongest complexation ability with Pb (logKSV: 8.16 × 103), followed by Cu (logKSV: 1.79 × 103), while their abilities for Cd and Zn were weaker. A spectroscopic analysis indicated that the primary functional groups involved in EPS binding with Pb/Cd and Cd/Zn were protein carboxyl groups (C=O/O-C=O) and glycosidic bonds (C-OH/C-O-C), respectively. This study elucidates the response strategies and adsorption mechanisms of the C. reinhardtii EPS to different metals and provides a basis for environmental heavy metal pollution bioremediation.

Effect of long-term negative energy on appetite hormone levels in individuals with prediabetes and diabetes.

Calorie restriction and exercise are commonly used first interventions to prevent the progression of prediabetes and alleviate the symptoms of type 2 diabetes. Our study was designed to determine the effect of the energy deficit caused by long-term (12-week) calorie restriction and exercise programs on appetite responses in obese individuals with prediabetes and type 2 diabetes. Calorie restriction and exercise programs appropriate for age, gender, and work environment were applied to 22 individuals with prediabetes and 22 with type 2 diabetes participating in the study for a period of 12 weeks. Ghrelin, glucagon-like peptide-1, and peptide tyrosine tyrosine values of samples taken before and after treatment were determined by the enzyme-linked ιmmunosorbent assay method. Appetite hormone levels did not change after calorie restriction and exercise in the prediabetes group (p>0.05). In the diabetes group, calorie restriction and exercise significantly increased ghrelin and peptide tyrosine tyrosine concentrations (p<0.005). Additionally, when all patients were evaluated together, ghrelin, glucagon-like peptide-1 and peptide tyrosine tyrosine levels differed significantly after the intervention (p<0.005). The energy deficit created by long-term calorie restriction and exercise did not modulate the appetite hormones in prediabetic and obese individuals. However, increased ghrelin and peptide tyrosine tyrosine levels in individuals with diabetes support that the same treatment program is an effective method to regulate appetite hormones.

Diagnosis, treatment, management and monitoring of patients with tyrosinaemia type 1: Consensus group recommendations from the German-speaking countries.

Hepatorenal tyrosinaemia (HT1) is an autosomal recessive disorder of tyrosine degradation resulting in hepatic and renal dysfunction, neurological sequelae may occur in some patients. The use of nitisinone (NTBC) has revolutionised treatment and outcome of this disorder. NTBC has to be combined with a low protein diet. While NTBC modulates the disease course in HT1 patients, several issues are open. Optimal dosage, doses per day, therapeutic range of NTBC concentration, mode of protein restriction and biomarkers are not well defined. HCC and neurocognitive deficits are long-term sequelae. Early diagnosis and treatment are essential to minimise the risk for these complications. Clinical guidance for management of HT1-patients is required. Randomised clinical studies are difficult in the presence of therapeutic options. We discussed these issues in a consensus group of 10 paediatricians, 1 adult hepatologist, 1 geneticist, 2 dieticians, 2 newborn screening specialists with experience in HT1, 1 psychologist and 2 representatives of a patient group from the German-speaking countries (DACH). Recommendations were based on scientific literature and expert opinion, also taking into account recent experience with newborn screening. There was strong consensus that newborn screening using succinylacetone (SA) and early treatment are essential for a good outcome. The dose of NTBC should be as low as possible without losing metabolic control. This has to be accompanied by a low protein diet, in some patients a simplified diet without calculation of protein intake. Specific education and psychosocial support are recommended. Indications for liver transplantation were defined. Monitoring shall include clinical findings, levels of SA, tyrosine, phenylalanine and NTBC in (dried) blood.

Assessment of the Relationship Between Amino Acid Status and Parkinson's Disease: A Comprehensive Review and Meta-analysis.

Parkinson's disease (PD) is characterized by the inability of dopamine production from amino acids. Therefore, changes in amino acid profile in PD patients are very critical for understanding disease development. Determination of amino acid levels in PD patients with a cumulative approach may enlighten the disease pathophysiology. A systematic search was performed until February 2023, resulting in 733 articles in PubMed, Web of Science and Scopus databases to evaluate the serum amino acid profile of PD patients. Relevant articles in English with mean/standard deviation values of serum amino acid levels of patients and their healthy controls were included in the meta-analysis. Our results suggest that valine, proline, ornithine and homocysteine levels were increased, while aspartate, citrulline, lysine and serine levels were significantly decreased in PD patients compared to healthy controls. Homocysteine showed positive correlations with glutamate and ornithine levels. We also analyzed the disease stage parameters: Unified Parkinson's Disease Rating Scale III (UPDRS III) score, Hoehn-Yahr Stage Score, disease duration and levodopa equivalent daily dose (LEDD) of patients. It was observed that LEDD has a negative correlation with arginine levels in patients. UPDRS III score is negatively correlated with phenylalanine levels, and it also tends to show a negative correlation with tyrosine levels. Disease duration tends to be negatively correlated with citrulline levels in PD patients. This cumulative analysis shows evidence of the relation between the mechanisms underlying amino acid metabolism in PD, which may have a great impact on disease development and new therapeutic strategies.

Amino Acid Composition of Dried Bovine Dairy Powders from a Range of Product Streams.

The amino acid (AA) content of multiple samples of various dairy powders was determined, providing a comprehensive evaluation of the differences in AA profiles attributable to distinct manufacturing processes. Products examined included whole milk powder (WMP), skim milk powder (SMP), cheese whey protein concentrate (WPC-C), lactic acid casein whey protein concentrate (WPC-L), high-fat whey protein concentrate (WPC-HF), hydrolyzed whey protein concentrate (WPH), whey protein isolate (WPI), and demineralized whey protein (D90). WMP and SMP exhibited broadly similar AA profiles, with minor differences likely due to the minimal milk fat protein content, which is nearly absent from SMP. Comparative analysis of WPC-C and WPC-L indicated higher levels of threonine, serine, glutamic acid, and proline in WPC-C but lower levels of tyrosine, phenylalanine, and tryptophan, attributed to the different methods of separation from casein proteins. WPI and WPC-HF originate from similar sweet whey streams but follow divergent processing methods; consequent on this were variations in the levels of all AAs except histidine. The nanofiltration step in D90 production retains its non-protein nitrogen content and affects its AA profile; consequently, D90 consistently exhibited lower AA levels than WPC-C. These findings underscore the significant impact of manufacturing processes on dairy powder AA composition.

Impact of extended lairage periods on physio-metabolic status and meat quality in commercial broilers

ABSTRACT 1. This study investigated the impact of different lairage duration on physiology, metabolism and meat quality in commercial broilers. 2. A total of sixty, one-d-old Vencobb broilers were reared until 42 d of age and subjected to five lairage treatments (T0-T5), with the control with no lairage and then each timepoint increasing by 2 h. 3. Head, eye and feet temperature increased progressively (P˂0.05), from 21 to 42 d. During lairage, temperature for the head, eye and feet were significantly higher in birds held until T3-T4 (P˂0.05), than at T0-T2 and T5 treatments. 4. Serum total protein, creatinine, lipase and TBARS showed no variation due to lairage (p > 0.05). Glucose levels were highest at T4 (p < 0.05) than at T1-T3 or T5 and serum albumin increased only at T4 as compared to T5 (p < 0.05). Higher levels for blood triglycerides were recorded for T0, T1 and T5 (p < 0.05), than at T2-T4 and total blood antioxidants were significantly higher at T1 (p < 0.05), than at T0 and T2-T5 treatments, respectively. 5. There was no significant difference for meat pH, ERV and WHC (p > 0.05), while, higher tyrosine levels (p < 0.05) were noted for birds in T5 than for the rest of the lairage treatments (T0-T4). On the same trend, TBA concentration was highest for birds in T5, as compared to T4 (p < 0.05). 6. In conclusion, lairage over eight hours for commercial broilers is not recommended, as there are drastic changes in physiology, metabolism and deterioration of meat, reducing meat quality.

Striatal and peripheral dopaminergic alterations related to cognitive impairment in patients with schizophrenia

Abstract Background Cognitive impairment, a major determinant of poor functioning in schizophrenia, had limited responses to existing antipsychotic drugs. The limited efficacy could be due to regional differences in the dysregulation of the dopamine system. This study investigated striatal and peripheral dopaminergic makers in schizophrenia and their relationship with cognitive impairment. Methods Thirty-three patients with schizophrenia and 36 age- and sex-matched healthy controls (HC) participated. We evaluated their cognitive performance, examined the availability of striatal dopamine transporter (DAT) using single-photon emission computed tomography with 99mTc-TRODAT, and measured plasma levels of dopaminergic precursors (phenylalanine and tyrosine) and three branched-chain amino acids (BCAA) that compete with precursors for brain uptake via ultra-performance liquid chromatography. Results Schizophrenia patients exhibited lower cognitive performance, decreased striatal DAT availability, and reduced levels of phenylalanine, tyrosine, leucine, and isoleucine, and the ratio of phenylalanine plus tyrosine to BCAA. Within the patient group, lower DAT availability in the left caudate nucleus (CN) or putamen was positively associated with attention deficits. Meanwhile, lower tyrosine levels and the ratio of phenylalanine plus tyrosine to BCAA were positively related to executive dysfunction. Among all participants, DAT availability in the right CN or putamen was positively related to memory function, and plasma phenylalanine level was positively associated with executive function. Conclusions This study supports the role of dopamine system abnormalities in cognitive impairment in schizophrenia. The distinct associations between different dopaminergic alterations and specific cognitive domain impairments suggest the potential need for multifaceted treatment approaches to target these impairments.

β-Triketones from Leptospermum scoparium (mānuka) oil show potential as scabicides.

Scabies is a debilitating and neglected infectious disease with limited effective treatment options and affecting millions of people worldwide, mainly in poor and overcrowded settings. Essential oils from Australasian Myrtaceae are known to have parasiticidal properties, often attributed to the presence of β-triketones, which are known inhibitors of the tyrosine catabolism pathway through inhibition of hydroxyphenylpyruvate dioxygenase (HPPD). In this study, essential oils from mānuka (Leptospermum scoparium) were evaluated in vitro for miticidal and ovicidal activities and their active β-triketone constituents (flavesone, leptospermone, and isoleptospermone) were identified. Mite survival and egg hatching bioassays were performed to assess the scabicidal (miticidal and ovicidal) properties of Australasian Myrtaceae essential oils (mānuka, tea tree, and kunzea), mānuka oil fractions and three β-triketones (leptospermone, isoleptospermone, flavesone). Scabicidal constituents of mānuka oil were determined and quantified by 1H NMR spectroscopy and gas chromatography. To investigate HPPD as a potential target of β-triketones in scabies, tyrosine and fumarate levels were measured in mites following exposure to flavesone, and in silico docking of β-triketones in homology models of scabies HPPD structures was performed. Mānuka oil had superior scabicidal activity compared to conventional treatments, ivermectin and permethrin, as well as kunzea and tea tree oils. The analysis of the chemical composition of mānuka oil revealed a high abundance of sesquiterpenes (42 %), and three β-triketones, flavesone (4.7 %), leptospermone (17.2 %), and isoleptospermone (5.1 %). Miticidal and ovicidal activity was strongly correlated with the presence of these β-triketones, but not the sesquiterpenes. The β-triketones had similar miticidal activity (LC50 58.6-61.7 mM at 4 h; LT50 1.3-1.4 h at 150 mM) to each other and to mānuka oil, and showed high ovicidal activity in young and mature eggs, with leptospermone being the most potent (LC50 33.6-75.9 mM). Significantly altered tyrosine and fumarate levels in mites after exposure to flavesone compared to untreated mites indicate a possible interference of flavesone with the tyrosine catabolism pathway. Molecular docking experiments indicate that this activity is likely underpinned by their inhibition of the Sarcoptes scabiei hydroxyphenylpyruvate dioxygenase (SsHPPD). Our results demonstrated that mānuka oil and the β-triketones flavesone, leptospermone, and isoleptospermone can effectively kill scabies mites and eggs at early and late developmental stages, likely through their inhibition of tyrosine catabolism. This work has revealed SsHPPD as a potential new target for the development of novel topical scabies drugs that target all life-stages of the parasite.

Metabolomic changes in Citrus reticulata peel after conventional and ultrasound-assisted solid-state fermentation with Aspergillus niger: A focus on flavonoid metabolism

This study explored the changes in nutrients, metabolites, and enzyme activity in Citrus reticulata peel powders (CRPP) under conventional or ultrasound-assisted solid-state fermentation (SSF) using Aspergillus niger CGMCC 3.6189. Compared to nonfermented CRPP (NF-CRPP), ultrasound-assisted fermented CRPP (UIS-CRPP) significantly increased total protein and carotenoid levels by 85.26 % and 179.68 %, respectively, surpassing conventionally-fermented CRPP (FO-CRPP). Among the 521 identified differential metabolites, organic acids, lipids, and flavonoids were predominant. Flavonoid accumulation was primarily driven by the flavone and flavonol biosynthesis pathway, with 90.47 % and 90.00 % of differential flavonoids upregulated in FO-CRPP and UIS-CRPP, respectively. SSF significantly increased phenylalanine, tyrosine, and methionine levels, and tyrosine ammonia-lyase and β-D-glucosidase activities, with higher levels in UIS-CRPP. These findings suggest that conventional and ultrasound-assisted fermentation enhances flavonoid levels in CRPP by modulating key enzyme activities in flavonoid biosynthesis and biotransformation. Our study offers a feasible approach for producing value-added products from citrus peel waste.

Schwann cells exposed to articaine display distinct toxic pathways compared to lidocaine

Articaine (ATC) has emerged as one of the most popular local anesthetics (LA) in dental clinics, despite its relatively recent introduction to the market. As a member of the amino-amide class of LA, ATC possesses unique features, including a thiophene ring and an ester group, which allow for its use at higher clinical concentrations. However, reports have indicated a higher incidence of paresthesia associated with ATC, though the underlying cause of this effect remains unclear. To investigate this further, we conducted an extracellular metabolic flux analysis and an NMR-based metabolomics study of ATC effects on Schwann cells - a type of glial cell found in the peripheral nervous system - in comparison to lidocaine (LDC), the “gold standard" LA in dentistry. The results showed that ATC had a more significant impact on Schwann cell oxygen consumption compared to LDC. Metabolomics profiling of Schwann cells revealed distinct metabolic alterations between the two treatments. Notably, ATC triggered elevated intracellular levels of various amino acids, including leucine, isoleucine, valine, phenylalanine, methionine, histidine, tyrosine, and glycine, which were not observed in LDC-treated Schwann cells. This was consistent with signs of endoplasmic reticulum stress and apoptosis in ATC-treated cells, as detected by protein expression analysis. These findings offer insights into the metabolic and cellular responses elicited by the two anesthetics in Schwann cells, that may help explain the differential toxicity and higher incidence of paresthesia associated with ATC.

Assessing Urinary Para-Hydroxyphenylacetic Acid as a Biomarker Candidate in Neuroendocrine Neoplasms.

The management of neuroendocrine neoplasms (NENs) involves the measurement of serum chromogranin A (s-CGA), serum neuro-specific enolase (s-NSE), and urinary 5-hydroxindolacetic acid (5-HIAA). Urinary para-hydroxyphenylacetic acid (u-pHPAA), a metabolite of tyrosine, has been proposed as a potential biomarker for these diseases. This study aims to evaluate the effectiveness of u-pHPAA and tyrosine as biomarkers. We measured the levels of s-CgA, s-NSE, u-5-HIAA, u-pHPAA, and tyrosine in blood or 24 h urine samples collected at baseline (T0) and after 1 year of follow-up (T1) from a limited cohort of patients enrolled at Istituto Nazionale Tumori-IRCCS-Fondazione "G. Pascale". Biomarker values were normalized using the ratios between T1 and T0 values (T1/T0 parameters). The T1/T0 ratios for s-CgA and u-pHPAA were significantly associated with the outcome of death (p = 0.044 and p = 0.022, respectively). An ROC curve analysis demonstrated outstanding performances for these biomarkers (AUC = 0.958 and AUC = 1.00, respectively) and the Kaplan-Meier survival analysis showed significant Log-rank test results (p = 0.001 and p < 0.001, respectively). Additionally, T0 serum tyrosine correlated with the outcome of death (p = 0.044), with the ROC curve showing good performance (AUC = 0.958) and the Kaplan-Meier analysis yielding significant Log-rank test results (p = 0.007). Our study confirms the role of s-CgA in the management of NEN patients and highlights the potential roles of u-pHPAA and serum tyrosine as biomarkers. Further research is needed to validate our findings in larger populations.

Association of phenylalanine and tyrosine metabolism with mortality and response to nutritional support among patients at nutritional risk: a secondary analysis of the randomized clinical trial EFFORT.

Elevated phenylalanine serum level is a surrogate marker of whole-body proteolysis and has been associated with increased mortality in critically ill patients. Tyrosine is a metabolite of phenylalanine and serves as a precursor of thyroid hormones and catecholamines with important functions in the oxidative stress response among others. Herein, we examined the prognostic significance of phenylalanine, tyrosine, as well as its metabolites nitrotyrosine, L-3,4-dihydroxyphenylalanine (DOPA), and dopamine regarding clinical outcomes and response to nutritional therapy in patients at nutritional risk. This is a secondary analysis of the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a randomized controlled trial investigating individualized nutritional support compared to standard care in patients at risk of malnutrition. The primary outcome was 30-day all-cause mortality. We analyzed data of 238 patients and found a significant association between low plasma levels of phenylalanine [adjusted HR 2.27 (95% CI 1.29 to 3.00)] and tyrosine [adjusted HR 1.91 (95% CI 1.11 to 3.28)] with increased 30-day mortality. This association persisted over a longer period, extending to 5 years. Additionally, trends indicated elevated mortality rates among patients with low nitrotyrosine and high DOPA and dopamine levels. Patients with high tyrosine levels showed a more pronounced response to nutritional support compared to patients with low tyrosine levels (HR 0.45 versus 1.46, p for interaction = 0.02). In medical inpatients at nutritional risk, low phenylalanine and tyrosine levels were associated with increased short-and long-term mortality and patients with high tyrosine levels showed a more pronounced response to nutritional support. Further research is warranted to gain a deeper understanding of phenylalanine and tyrosine pathways, their association with clinical outcomes in patients at nutritional risk, as well as their response to nutritional therapy. www.clinicaltrials.gov, identifier NCT02517476.

The effects of casein glycomacropeptide on general health status in children with PKU: A randomized crossover trial

In PKU, it is suggested that casein glycomacropeptide based protein substitute (GMP) may have physiological advantage when satiety, oxidative stress, renal function and inflammation are considered. Its prebiotic properties may also help gastrointestinal (GI) tolerance.In children with PKU, a randomized/crossover trial comparing phenylalanine-free amino acids (AA) vs GMP as the single source of protein substitute for 12-weeks in each arm was conducted. There was a 4-week wash out period with AA in-between. At baseline and end of each intervention, blood and fecal samples were taken to monitor gut health, oxidative stress, renal function, inflammatory markers and plasma amino acids. Satiety and Pediatric Quality of Life (PedsQL) GI symptoms questionnaires were completed. Usual weekly blood spots for phenylalanine and tyrosine were done.Twelve patients (8 males; aged 4-9y) with PKU participated. GMP improved the following GI symptoms: stomach pain (p = 0.003), heartburn and reflux (p = 0.041) wind and bloating (p = 0.018). With GMP, there was also a trend for less constipation (p = 0.068), discomfort with eating (p = 0.065) and nausea and vomiting (p = 0.087). There were no changes on stool gut health markers (IgA, short chain fatty acids and fecal calprotectin). There were no statistically significant differences for renal, oxidative stress, inflammatory and gut health markers or measures of satiety except for adiponectin (p = 0.028) and total antioxidant capacity (p = 0.049), although the latter was possibly without clinical significance. Mean dried blood spot phenylalanine (Phe) was 114 μmol/L higher with GMP vs AA (p < 0.001). There was no difference in tyrosine levels. In conclusion, GI symptoms statistically significantly improved with GMP versus AA. The Phe content of GMP may present challenges when it is used as the only protein substitute in children with classical PKU with low Phe tolerance.

A simplified liquid chromatography-mass spectrometry methodology to probe the shikimate and aromatic amino acid biosynthetic pathways in plants.

Plants direct substantial amounts of carbon toward the biosynthesis of aromatic amino acids (AAAs), particularly phenylalanine to produce lignin and other phenylpropanoids. Yet, we have a limited understanding of how plants regulate AAA metabolism, partially because of a scarcity of robust analytical methods. Here, we established a simplified workflow for simultaneous quantification of AAAs and their pathway intermediates from plant tissues, based on extraction at two alternative pH and analysis by Zwitterionic hydrophilic interaction liquid chromatography coupled to mass spectrometry. This workflow was then used to analyze metabolic responses to elevated or reduced carbon flow through the shikimate pathway in plants. Increased flow upon expression of a feedback-insensitive isoform of the first shikimate pathway enzyme elevated all AAAs and pathway intermediates, especially arogenate, the last common precursor within the post-chorismate pathway of tyrosine and phenylalanine biosynthesis. Additional overexpression of an arogenate dehydrogenase enzyme increased tyrosine levels and depleted phenylalanine and arogenate pools; however, the upstream shikimate pathway intermediates remained accumulated at high levels. Glyphosate treatment, which restricts carbon flow through the shikimate pathway by inhibiting its penultimate step, led to a predictable accumulation of shikimate and other precursors upstream of its target enzyme but also caused an unexpected accumulation of downstream metabolites, including arogenate. These findings highlight that the shikimate pathway and the downstream post-chorismate AAA pathways function as independently regulated modules in plants. The method developed here paves the way for a deeper understanding of the shikimate and AAA biosynthetic pathways in plants.

Novel insights of phenylalanine in Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) and cardiovascular complications

Abstract Background Metabolic dysfunction-associated steatotic liver disease (MASLD) is linked to cardiovascular risk, necessitating an exploration of potential metabolic contributors, such as amino acids. While amino acids are implicated in metabolic disorders, their specific relationship with MASLD and subsequent cardiovascular complications is not well-defined. We aimed to delineate the association between circulating amino acids and MASLD, identifying amino acids that could potentially link MASLD to cardiovascular issues. Methods Utilizing UK Biobank data, we tested the association of ten amino acids with MASLD in a cohort of 72,626 MASLD cases and 128,102 controls. Afterwards, we performed Mendelian Randomization (MR) using genome-wide association study (GWAS) data from 8,434 MASLD cases and 770,180 controls, and GWAS of amino acids including 115,052 participants from UK Biobank. Multiple MR methods, including MR-Egger, Cochran's Q-test, and MR-PRESSO, were applied to assess pleiotropy and heterogeneity. Survival analysis in MASLD patients assessed the link between significant amino acid and incident severe cardiovascular outcomes, including stroke, heart failure, myocardial infarction, and mortality, using three different covariate combinations: Model 1 included age, sex, and fasting time; Model 2 included in addition smoking, alcohol use, education, physical activity, and Model 3 included body mass index (BMI) in addition to model 2. Results Nine out of the ten amino acids were statistically significantly associated with MASLD across all three models (p&amp;lt;6.25×10^-3). Among them valine, leucine, isoleucine, total branched-chain amino acids, tyrosine, alanine, and phenylalanine were positively associated with MASLD, while glutamine and glycine were negatively associated with MASLD. The genetic predisposition of MASLD was significantly associated with increased phenylalanine (beta=0.05, p=4.0×10^-4) and tyrosine (beta=0.15, p=2.0×10^-3), suggesting that alterations in these amino acids may result from the progression of MASLD. We also detected heterogeneity (Cochran’s Q-test: p=8.4×10^-9) and pleiotropy (MR-Egger: p=0.02) for tyrosine, but not for phenylalanine. Furthermore, phenylalanine levels in MASLD patients were significantly (p&amp;lt;6.25×10^-3) associated with the incidence of heart failure, stroke, and mortality, but not with myocardial infarction across all three models. We did not identify a significant association between baseline tyrosine levels and any cardiovascular complications or mortality across the three models (Figure 1). Conclusion Our findings indicate a strong association between certain amino acids and MASLD, with phenylalanine, in particular, emerging as a potential mediator of cardiovascular risk in MASLD patients. The absence of heterogeneity and pleiotropy for phenylalanine strengthens its candidacy as a biomarker for future cardiovascular complications in MASLD.

Estrogen Enhances FDFT1 Expression in Theca Cells of Chicken Hierarchical Ovarian Follicles by Increasing LSD1Ser54p Level Through GSK3β Phosphorylation at 216th Tyrosine.

The development of chicken ovarian follicles involves two key stages of primordial follicle recruitment and follicle selection that are tightly regulated by multiple reproductive hormones and cytokines. Our previous study revealed an estrogen-stimulated increase in the phosphorylation level of serine at position 54 of lysine demethylase 1A (LSD1Ser54p) in the theca cells of chicken hierarchical ovarian follicles (Post-TCs). In this study, we further found that the upregulation of LSD1Ser54p by estrogen was performed by glycogen synthase kinase 3 beta (GSK3β) and that GSK3β promoted LSD1Ser54p levels by directly binding to the SWIRM and AOL1 domains of LSD1. Upon estrogen stimulation, the phosphorylation level of tyrosine at position 216 of GSK3β (GSK3βTyr216p) increased, which enhanced the binding between LSD1 and GSK3β. The subsequent transcriptome sequencing on chicken Post-TCs treated with estrogen and CUT&RUN sequencing against the LSD1Ser54p protein revealed that the expression of the farnesyl-diphosphate farnesyltransferase 1 (FDFT1) gene was simultaneously upregulated by estrogen, GSK3β, and LSD1Ser54p. Moreover, the overexpression of FDFT1 further promoted cholesterol biosynthesis in chicken Post-TCs. In short, the findings of this study suggest that estrogen-induced tyrosine phosphorylation at position 216 of GSK3β can upregulate the level of LSD1Ser54p, leading to the activation of FDFT1 expression and subsequently promoting cholesterol biosynthesis in chicken Post-TCs, which may in turn enhance estrogen synthesis.

Metabolite, Biochemical, and Dietary Intake Alterations Associated with Lifestyle Interventions in Obese and Overweight Malaysian Women.

Differences in metabolic regulation among obesity phenotypes, specifically metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) women, may lead to varied responses to interventions, which could be elucidated through metabolomics. Therefore, this study aims to investigate the differences in metabolite profiles between MHO and MUO women and the changes following a lifestyle intervention. Serum samples from 36 MHO and 34 MUO women who participated in a lifestyle intervention for weight loss were analysed using untargeted proton nuclear magnetic resonance spectroscopy (1H NMR) at baseline and 6 months post-intervention. Anthropometric, clinical, and dietary intake parameters were assessed at both time points. Both groups showed differential metabolite profiles at baseline and after six months. Seven metabolites, including trimethylamine-N-oxide (TMAO), arginine, ribose, aspartate, carnitine, choline, and tyrosine, significantly changed between groups post-intervention, which all showed a decreasing pattern in MHO. Significant reductions in body weight and body mass index (BMI) in the MUO correlated with changes in the carnitine and tyrosine levels. In conclusion, metabolite profiles differed significantly between MHO and MUO women before and after a lifestyle intervention. The changes in carnitine and tyrosine levels in MUO were correlated with weight loss, suggesting potential targets for therapeutic intervention.

Enhancing acid resistance of Escherichia coli based on directed morphology evolutionary of key transcription factor bolA

Succinic acid, as one of the important fermentation products, is commonly used as an acidulant, flavoring agent, and antimicrobial agent. However, the accumulation of organic acids in the later fermentation phase will restrict the production efficiency of strain. To address this issue, the directed evolution on the key transcription morphology factor bolA gene was performed to enhance acid resistance of Escherichia coli by ep-PCR library and CRISPR/Cas9. The best mutant strain 5-21-5 was screened from 4000 mutant colonies ep-PCR library, which showed higher cell survives in succinic acid stress. Its acid resistance ability was systematically illustrated from multiple aspects by transmission electron microscope (TEM), confocal laser scanning microscopy (CLSM), and three-dimensional excitation emission matrix (3D-EEM) analysis, respectively. Higher tyrosine and tryptophan protein level was beneficial to acid resistance, while cell tend to short rod shape. Subsequently, with the assistance of the CRISPR/Cas9 gene editing technology knocking the mutated sequences into the genome, the succinic acid yield of strain M-K10 reached 9.8 g/L, representing a 15.29% increase compared to the Escherichia coli MG1655 without gene editing.