Liquid Chromatography-tandem Mass Spectrometry Research Articles

Effect of abiotic and biotic elicitors on vincristine accumulation in endosperm derived in vitro cultures in Catharanthus roseous (L.) G. Don

Catharanthus roseus (L.) G. Don (Apocynaceae) is a well-studied herb renowned for its in vitro culture as a source of the anti-cancer alkaloid, vincristine. However, despite the recognized advantages of triploid cells over diploid cells in terms of productivity, the triploid endosperm tissue of this important medicinal plant has not been utilized for in vitro culture initiation. In this investigation, zygotic embryos and endosperm tissues were cultured on Murashige and Skoog (MS) medium supplemented with various combinations of auxins and cytokinins. The medium containing 2.50 µM 6-Benzyladenine (BA) and 1.25 µM 2,4-Dichlorophenoxyacetic acid (2,4-D) proved to be the most effective for callus and cell culture formation. Ploidy analysis using ploidy analyzer confirmed that the endosperm-derived callus exhibited mixoploid, while the embryo-derived callus remained diploid. Liquid Chromatography Mass Spectrometry (LC–MS) analysis of callus and cell cultures grown on MS media with different combinations of auxins, cytokinins, elicitors, and precursors (both biotic and abiotic) revealed the accumulation of vincristine. Notably, treatment with a biotic elicitor derived from Aspergillus niger (300 mg/l) demonstrated superior efficacy in promoting the maximum accumulation of vincristine in endosperm-derived callus and cell biomass. These findings hold promise for the sustainable production of the anti-cancer alkaloid vincristine from endosperm-derived callus and cell cultures of Catharanthus roseus.

Acaricidal activity of Egyptian crude plant extracts against Haemaphysalis longicornis ticks.

Haemaphysalis longicornis is a common Ixodida tick species found in temperate areas of Asian countries. An anti-tick assay was conducted on adult female H. longicornis ticks. Plant extract solutions were prepared at concentrations of 50, 25, and 10 mg/mL. Tick survival and mortality were assessed by counting the number of dead and live ticks at 24 h, 48 h, 72 h, and 96 h posttreatment. Out of 11 plant extracts screened, Artemisia judaica extract exhibited the highest potency with 100% mortality (5/5) at 48 h when applied at high and moderate concentrations (50 and 25 mg/mL). Similar results were observed at 96 h for the 10 mg/mL group compared to the untreated ticks. Cleome droserifolia extract demonstrated partial activity with 60% (3/5) and 20% (1/5) mortality at 96 h posttreatment at concentrations of 50 and 25 mg/mL, respectively. Forsskaolea tenacissima extract showed a weak effect with 100% tick mortality (5/5) only at the highest treatment concentration after 96 h. To confirm the activity of A. judaica, trial 2 was conducted. A. judaica demonstrated potency within 48 h in high dose and 72 h in moderate dose, with 100% mortality (15/15) at 96 h posttreatment compared to untreated ticks. The median lethal time 50 (LT50) values were 30.37 h for the high and 55.08 h for the moderate doses. Liquid chromatography‒mass spectrometry was performed on the most potent candidate (A. judaica) to identify its phytochemical components. The results revealed the presence of 9 compounds identified through manual annotation and 74 compounds from the Global Natural Products Social library. These compounds included terpenoids, steroids, phenylpropanoids, flavonoid glycosides, flavonoids, and benzenoids. Camphor was identified as the major component via both approaches. These findings suggest the potential use of A. judaica extract in the future development of acaricidal therapeutics.

Sphingosine Promotes Fiber Early Elongation in Upland Cotton

Sphingolipids play an important role in cotton fiber development, but the regulatory mechanism is largely unclear. We found that serine palmitoyltransferase (SPT) enzyme inhibitors, myriocin and sphingosine (dihydrosphingosine (DHS) and phytosphingosine (PHS)), affected early fiber elongation in cotton, and we performed a sphingolipidomic and transcriptomic analysis of control and PHS-treated fibers. Myriocin inhibited fiber elongation, while DHS and PHS promoted it in a dose–effect manner. Using liquid chromatography–tandem mass spectrometry (LC–MS/MS), we found that contents of 22 sphingolipids in the PHS-treated fibers for 10 days were changed, of which the contents of 4 sphingolipids increased and 18 sphingolipids decreased. The transcriptome analysis identified 432 differentially expressed genes (238 up-regulated and 194 down-regulated) in the PHS-treated fibers. Among them, the phenylpropanoid biosynthesis pathway is the most significant enrichment. The expression levels of transcription factors such as MYB, ERF, LBD, and bHLH in the fibers also changed, and most of MYB and ERF were up-regulated. Auxin-related genes IAA, GH3 and BIG GRAIN 1 were up-regulated, while ABPs were down-regulated, and the contents of 3 auxin metabolites were decreased. Our results provide important sphingolipid metabolites and regulatory pathways that influence fiber elongation.

Amino Acid Profile Alterations in Phenylketonuria: Implications for Clinical Practice

Patients with phenylketonuria (PKU) must restrict their intake of phenylalanine, which can also affect the levels of other essential and non-essential amino acids due to inadequate supply. Therefore, our objective was to assess amino acids in serum samples from 20 PKU patients and compare them with results from 51 healthy subjects. A sample analysis was conducted using liquid chromatography–tandem mass spectrometry. We obtained levels of 28 substances, including amino acids, biogenic amines, carnitine, and acetylcarnitine. Kynurenine (p = 0.000001), tyrosine (p = 0.0002), asparagine (p = 0.001), proline (p = 0.012), and the kynurenine/tryptophan ratio (p < 0.000001) were identified as features that differed between the studied groups, being significantly lower in patients with PKU. Glycine (p = 0.000012), putrescine (p = 0.0055), asymmetric dimethylarginine (p = 0.01), creatinine (p = 0.035) levels, as well as the total level of glucogenic amino acids (p = 0.0018), and the ratios of putrescine/ornithine (p = 0.003) and citrulline/ornithine (p = 0.0043) were significantly higher in the PKU group. In conclusion, the amino acid profiles in patients with PKU differ significantly from those in healthy peers, with potential clinical implications. These findings confirm the importance of metabolic testing in clinical practice and highlight the necessity for adequate dietary monitoring and adjustment.

Synthesis of a cysteine functional covalent organic framework via facile click reaction for the efficient solid phase extraction of substituted p-phenylenediamine-derived quinones

N,N′-Substituted p-phenylenediamine quinones (PPD-Qs) are the emerging toxicant, which transform from the rubber tire antioxidant N,N′-substituted p-phenylenediamines (PPDs). Because of their potential toxic and widespread occurrence in the environment, PPD-Qs have received great attention. However, efficiently extracting PPD-Qs from complex samples is still a challenge. Herein, a cysteine functional covalent organic framework (Cys-COF) designed according to the “donor-acceptor” sites of hydrogen bonding of PPD-Qs was synthesized via click reaction and then used as solid-phase extraction (SPE) adsorbent. Cys-COF can form the seven-member ring adsorption structure with PPD-Qs via hydrogen bonding. The adsorption mechanism was tentatively revealed by density functional theory (DFT). After optimizing the Cys-COF-SPE parameters, PPD-Qs were efficiently extracted from water, soil, sediment, and fish, followed by detection using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The Cys-COF-SPE-UHPLC-MS/MS method exhibited ideal linearity (R2 ≥ 0.9932), high relative recoveries (80.4–111 %), and low limits of detection (0.0001–0.0013 ng mL−1). In addition, the bioconcentration kinetics in goldfish provides a feasible platform to investigate the toxicity and accumulated ability of PPD-Qs.

Innovating Thiopurine Therapeutic Drug Monitoring: A Systematic Review and Meta-Analysis on DNA-Thioguanine Nucleotides (DNA-TG) as an Inclusive Biomarker in Thiopurine Therapy.

Thioguanine (TG), azathioprine (AZA), and mercaptopurine (MP) are thiopurine prodrugs commonly used to treat diseases, such as leukemia and inflammatory bowel disease (IBD). 6-thioguanine nucleotides (6-TGNs) have been commonly used for monitoring treatment. High levels of 6-TGNs in red blood cells (RBCs) have been associated with leukopenia, the cutoff levels that predict this side effect remain uncertain. Thiopurines are metabolized and incorporated into leukocyte DNA. Measuring levels of DNA-incorporated thioguanine (DNA-TG) may be a more suitable method for predicting clinical response and toxicities such as leukopenia. Unfortunately, most methodologies to assay 6-TGNs are unable to identify the impact of NUDT15 variants, effecting mostly ethnic populations (e.g., Chinese, Indian, Malay, Japanese, and Hispanics). DNA-TG tackles this problem by directly measuring thioguanine in the DNA, which can be influenced by both TPMT and NUDT15 variants. While RBC 6-TGN concentrations have traditionally been used to optimize thiopurine therapy due to their ease and affordability of measurement, recent developments in liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques have made measuring DNA-TG concentrations in lymphocytes accurate, reproducible, and affordable. The objective of this systematic review was to assess the current evidence of DNA-TG levels as marker for thiopurine therapy, especially with regards to NUDT15 variants. A systematic review and meta-analysis were performed on the current evidence for DNA-TG as a marker for monitoring thiopurine therapy, including methods for measurement and the illustrative relationship between DNA-TG and various gene variants (such as TPMT, NUDT15, ITPA, NT5C2, and MRP4). PubMed and Embase were systematically searched up to April 2024 for published studies, using the keyword "DNA-TG" with MeSH terms and synonyms. The electronic search strategy was augmented by a manual examination of references cited in articles, recent reviews, editorials, and meta-analyses. A meta-analysis was performed using R studio 4.1.3. to investigate the difference between the coefficients (Fisher's z-transformed correlation coefficient) of DNA-TG and 6-TGNs levels. A meta-analysis was performed using RevMan version 5.4 to investigate the difference in DNA-TG levels between patients with or without leukopenia using randomized effect size model. The risk of bias was assessed using the Newcastle-Ottowa quality assessment scale. In this systematic review, 21 studies were included that measured DNA-TG levels in white blood cells for either patients with ALL (n = 16) or IBD (n = 5). In our meta-analysis, the overall mean difference between patients with leukopenia (ALL + IBD) versus no leukopenia was 134.15 fmol TG/µg DNA [95% confidence interval (CI) (83.78-184.35), P < 0.00001; heterogeneity chi squared of 5.62, I2 of 47%]. There was a significant difference in DNA-TG levels for patients with IBD with and without leukopenia [161.76 fmol TG/µg DNA; 95% CI (126.23-197.29), P < 0.00001; heterogeneity chi squared of 0.20, I2 of 0%]. No significant difference was found in DNA-TG level between patients with ALL with or without leukopenia (57.71 fmol TG/µg DNA [95% CI (-22.93 to 138.35), P < 0.80]). DNA-TG monitoring was found to be a promising method for predicting relapse rates in patients with ALL, and DNA-TG levels are likely a better predictor for leukopenia in patients with IBD than RBC 6-TGNs levels. DNA-TG levels have been shown to correlate with various gene variants (TPMT, NUDT15, ITPA, and MRP4) in various studies, points to its potential as a more informative marker for guiding thiopurine therapy across diverse genetic backgrounds. This systematic review strongly supports the further investigation of DNA-TG as a marker for monitoring thiopurine therapy. Its correlation with treatment outcomes, such as relapse-free survival in ALL and the risk of leukopenia in IBD, underscores its role in enhancing personalized treatment approaches. DNA-TG effectively identifies NUDT15 variants and predicts late leukopenia in patients with IBD, regardless of their NUDT15 variant status. The recommended threshold for late leukopenia prediction in patients with IBD with DNA-TG is suggested to be between 320 and 340 fmol/µg DNA. More clinical research on DNA-TG implementation is mandatory to improve patient care and to improve inclusivity in thiopurine treatment.

Formation of Micelles by Nonionic Detergent Molecules Leads to the Breakthrough Peak in Reversed-Phase Ultraperformance Liquid Chromatography (UPLC).

A peculiar phenomenon known as "breakthrough" occurs under reversed-phase ultraperformance liquid chromatography (UPLC) conditions and has been under scrutiny for decades. This effect takes place when a large volume of analyte solution, prepared in a solvent with an eluotropic strength significantly higher than that of the initial mobile phase solvent, is injected. According to the literature, under specific experimental conditions, a substantial portion of solutes is carried by the mobile phase and detected near the dead time of the chromatographic system. This phenomenon is typically observed when the injected volume of a particular analyte is sufficiently large. However, the underlying physicochemical principles governing this phenomenon have remained elusive. We present evidence demonstrating that breakthroughs can occur even when injecting a sample of a neat solvent devoid of any solute. By mass spectrometric analysis, we identified the breakthrough peak to represent the nonionic detergent Triton. When columns are equilibrated with water, Triton molecules, present as impurities in filtered water, accumulate on the nonpolar stationary phase. Upon the introduction of a solvent with a stronger elution strength, Triton molecules retained on the stationary phase are removed. As detergents, these Triton molecules aggregate into micelles featuring a hydrophobic inner core and a hydrophilic outer shell. These hydrophilic micelles are carried by the polar mobile phase and detected as the breakthrough peak at the dead time of the chromatographic system. When analytes are present, a portion of the injected solutes is captured by the micelles and transported with the breakthrough plug. This assertion was verified and confirmed by liquid chromatography-mass spectrometry (LC-MS) analysis of a methanolic solution of perfluorooctanoic acid (PFOA). The mass spectra corresponding to the breakthrough plug featured a peak for the PFOA anion (m/z 413) in addition to those for Triton.

Metabolomic Profiles in Jamaican Children With and Without Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with a wide range of behavioral and cognitive impairments. While genetic and environmental factors are known to contribute to its etiology, metabolic perturbations associated with ASD, which can potentially connect genetic and environmental factors, remain poorly understood. Therefore, we conducted a metabolomic case-control study and performed a comprehensive analysis to identify significant alterations in metabolite profiles between children with ASD and typically developing (TD) controls in order to identify specific metabolites that may serve as biomarkers for the disorder. We conducted metabolomic profiling on plasma samples from participants in the second phase of Epidemiological Research on Autism in Jamaica, an age and sex-matched cohort of 200 children with ASD and 200 TD controls (2-8years old). Using high-throughput liquid chromatography-mass spectrometry techniques, we performed a targeted metabolite analysis, encompassing amino acids, lipids, carbohydrates, and other key metabolic compounds. After quality control and missing data imputation, we performed univariable and multivariable analysis using normalized metabolites while adjusting for covariates, age, sex, socioeconomic status, and child's parish of birth. Our findings revealed unique metabolic patterns in children with ASD for four metabolites compared to TD controls. Notably, three metabolites were fatty acids, including myristoleic acid, eicosatetraenoic acid, and octadecenoic acid. The amino acid sarcosine exhibited a significant association with ASD. These findings highlight the role of metabolites in the etiology of ASD and suggest opportunities for the development of targeted interventions.

The influence of different abiotic conditions on the concentrations of free and conjugated deoxynivalenol and zearalenone in stored wheat.

Environmental factors influence fungal growth and mycotoxin production in stored grains. However, the concentrations of free mycotoxins and their conjugates and how they are impacted by different interacting environment conditions have not been previously examined. The objectives of this study were to examine the impact of storage conditions (0.93-0.98 aw) and temperature (20-25°C) on (a) the concentrations of deoxynivalenol and zearalenone and their respective glucosides/conjugates and (b) the concentrations of emerging mycotoxins in both naturally contaminated and irradiated wheat grains inoculated with Fusarium graminearum. Contaminated samples were analysed for multiple mycotoxins using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Method validation was performed according to the acceptable performance criteria set and updated by the European Commission regulations No. 2021/808/EC. As an important conjugate of deoxynivalenol, the concentrations of deoxynivalenol-3-glucoside were significantly different from its precursor deoxynivalenol at 0.93 aw (22% moisture content- MC) at 25°C in the naturally contaminated wheat with a ratio proportion of 56:44% respectively. The high concentrations of deoxynivalenol-3-glucoside could be influenced by the wheat's variety and/or harvested season/fungal strain type/location. Zeralenone-14-sulfate concentrations were surprisingly three times higher than Zearalenone in the naturally contaminated wheat at 0.98 aw (26% MC) at both temperatures. Emerging mycotoxins such as moniliformin increased with temperature rise with the highest concentrations at 0.95 aw and 25°C. These findings highlight the influence and importance of storage aw x temperature conditions on the relative presence of free vs conjugated mycotoxins which can have implications for food safety.

Associations of methylmalonic acid and depressive symptoms with mortality: a population-based study

Methylmalonic acid (MMA), a biomarker of mitochondrial dysfunction, has been reported to be associated with depression in specific populations (i.e., older adults and postpartum women). Our study aimed to investigate to what extent MMA was associated with depressive symptoms and mortality in the general population, and assess whether depressive symptoms mediate the relationship between MMA and mortality. We analyzed cross-sectional data from 8343 participants from the US National Health and Nutrition Examination Survey. MMA was measured by liquid chromatography-tandem mass spectrometry, while depressive symptoms were measured by the Patient Health Questionnaire-9. Mortality data were obtained through linkage with National Death Index records. Linear regression models were performed to assess the association between MMA and depressive symptoms. The Cox proportional hazard regression model was utilized to assess the association of MMA and depressive symptoms with mortality. Mediation analysis was conducted within the counterfactual framework. In this general population, each SD (around 0.49 μmol/L) increase in MMA was associated with a 0.03 SD (approximately 0.15 score) increase in depressive symptoms (β = 0.033, 95% CI: 0.010, 0.055, p = 0.005). Notably, this association was more pronounced in men and participants over 60 years old. Higher levels of MMA and having more depressive symptoms were associated with a higher risk of mortality. However, depressive symptoms do not mediate the relationship between MMA and mortality. Elevated MMA levels were associated with depressive symptoms and an increased risk of mortality. These findings suggest that mitochondrial dysfunction may contribute to the multifactorial etiology of depression.

IN SILICO STUDIES OF IDENTIFIED COMPOUNDS FROM ETHANOLIC EXTRACT OF CELOSIA TRIGYNA AGAINST NEMATODE (Meloidogyne incognita)

Plant-parasitic nematodes (PPNs) have been found to be a major cause of considerable economic burden on the horticultural crops industry. Celosia genus have been renown to purpose antimicrobial activity. This study tends to swing the antimicrobial activity of one species of this genus i.e. Celosia trigyna against root-knot nematodes employing molecular docking methods. The identification of compounds in the leaf extract with the potential to inhibit Meloidogyne incognita was carried out in silico. Liquid Chromatography Mass Spectrometry (LCMS) was employed for analysis of the ethanolic leaf extract of this plant, it revealed the presence of cis-9-tetradecanoic acid, vitexin-glucoside, 6”-O-deoxyhexoside, gallic acid, malic acid, sinapic acid, 3-feruloylquinic acid in the extract. Site-directed multiligand docking of the identified compounds was performed on protein 2MIF of Meloidogyne incognita and employing Bifenazate and Boscalid as positive controls. The binding affinity of 3-feruloylquinic (– 4.2 kcal/mol) was significantly higher than the positive control compounds i.e. Bifenazate and Boscalid (– 4.0 kcal/mol and – 3.9 kcal/mol). The interactions of this molecule with the amino acids of the protein showed that the mechanism of its inhibitory action is similar to that of the cocrystallized ligand. This result validates that the antimicrobial activity of the ethanolic extract of the leaves of C. trigyna could be employed against root-knot nematodes for sustainable agriculture.

Development of LC–MS/MS Method for the Simultaneous Detection of Emerging Contaminants in Aquatic Matrices

Emerging contaminants (ECs) are substances that have no defined environmental quality standards or regulations, and have the potential to pose major adverse impacts on the environment and human health. The detection of contaminants in the natural environment is the key step for establishing precise environmental risk assessment approach for ECs. However, ECs come from different origins with various physicochemical properties, making their detection a complicated process. Moreover, their presence in the aquatic environment at trace concentration range (ng/L-µg/L), requires an accurate detection at low concentration levels. This study aims to develop an efficient analytical method for simultaneous determination of 5 different ECs in aqueous solution based on solid phase extraction technique (SPE) followed by liquid chromatography-mass spectrometry (LC–MS/MS). High recovery rates (72% to 114%) were achieved for all targeted compounds. Ciprofloxacin (CIP), diuron (DIU), terbutryn (TER) and diclofenac (DIC) had a limit of detection (LOD) of 5 µg/L and a limit of quantification (LOQ) of 10 ng/L, while LOD and LOQ for EE2 were 25 µg/L and 50 ng/L, respectively. These results confirm that the optimized method can be applied for extraction and analysis of ECs from different classes in the aquatic environment.

Huangqin Tang Alleviates Colitis-associated Colorectal Cancer via Amino Acids Homeostasisand PI3K/AKT/mTOR Pathway Modulation

Huangqin Tang (HQT), a traditional Chinese medicine formula, is commonly used in clinical practice for the treatment of inflammatory bowel diseases. It has been reported that HQT exerts antitumor effects on colitis-associated colorectal cancer (CAC). However, the mechanism by which HQT interferes with the inflammation-to-cancer transformation remains unclear. The purpose of this study was to dynamically evaluate the efficacy of HQT in alleviating or delaying CAC and to reveal the underlying mechanism. We established a mouse model of CAC using azoxymethane combined with 1.5% dextran sodium sulphate. The efficacy of HQT was evaluated based on pathological sections and serum biochemical indices. Subsequently, amino acids (AAs) metabolism analyses were performed using ultra-performance liquid chromatography-tandem mass spectrometry, and the phosphatidylinositol 3 kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) pathway was detected by western blotting. The data demonstrated that HQT could alleviate the development of CAC in the animal model. HQT effectively reduced the inflammatory response, particularly interleukin-6 (IL-6), in the inflammation induction stage, as well as in the stages of proliferation initiation and tumorigenesis. During the proliferation initiation and tumorigenesis stages, immunohistochemistry staining showed that the expression of the proliferation marker Ki67 was reduced, while apoptosis was increased in the HQT group. Accordingly, HQT substantially decreased the levels of specific AAs in the colon with CAC, including glutamic acid, glutamine, arginine, and isoleucine. Furthermore, HQT significantly inhibited the activated PI3K/AKT/mTOR pathway, which may contribute to suppression of cell proliferation and enhancement of apoptosis. HQT is effective in alleviating and delaying the colon "inflammation-to-cancer". The mechanism of action may involve HQT maintained AAs metabolism homeostasis and regulated PI3K/AKT/mTOR pathway, so as to maintain the balance between proliferation and apoptosis, and then interfere in the occurrence and development of CAC.

Targeting N4-acetylcytidine suppresses hepatocellular carcinoma progression by repressing eEF2-mediated HMGB2 mRNA translation.

N4-acetylcytidine (ac4C) represents a novel messenger RNA (mRNA) modification, and its associated acetyltransferase N-acetyltransferase 10 (NAT10) plays a crucial role in the initiation and progression of tumors by regulating mRNA functionality. However, its role in hepatocellular carcinoma (HCC) development and prognosis is largely unknown. This study aimed to elucidate the role of NAT10-mediated ac4C in HCC progression and provide a promising therapeutic approach. The ac4C levels were evaluated by dot blot and ultra-performance liquid chromatography-tandem mass spectrometry with harvested HCC tissues. The expression of NAT10 was investigated using quantitative real-time polymerase chain reaction, western blotting, and immunohistochemical staining across 91 cohorts of HCC patients. To explore the underlying mechanisms of NAT10-ac4C in HCC, we employed a comprehensive approach integrating acetylated RNA immunoprecipitation and sequencing, RNA sequencing and ribosome profiling analyses, along with RNA immunoprecipitation, RNA pull-down, mass spectrometry, and site-specific mutation analyses. The drug affinity responsive targets stability, cellular thermal shift assay, and surface plasmon resonance assays were performed to assess the specific binding of NAT10 and Panobinostat. Furthermore, the efficacy of targeting NAT10-ac4C for HCC treatment was elucidated through in vitro experiments using HCC cells and in vivo HCC mouse models. Our investigation revealed a significant increase in both the ac4C RNA level and NAT10 expression in HCC. Notably, elevated NAT10 expression was associated with poor outcomes in HCC patients. Functionally, silencing NAT10 suppressed HCC proliferation and metastasis in vitro and in vivo. Mechanistically, NAT10 stimulates the ac4C modification within the coding sequence (CDS) of high mobility group protein B2 (HMGB2), which subsequently enhances HMGB2 translation by facilitating eukaryotic elongation factor 2 (eEF2) binding to the ac4C sites on HMGB2 mRNA's CDS. Additionally, high-throughput compound library screening revealed Panobinostat as a potent inhibitor of NAT10-mediated ac4C modification. This inhibition significantly attenuated HCC growth and metastasis in both in vitro experiments using HCC cells and in vivo HCC mouse models. Our study identified a novel oncogenic epi-transcriptome axis involving NAT10-ac4C/eEF2-HMGB2, which plays a pivotal role in regulating HCC growth and metastasis. The drug Panobinostat validates the therapeutic potential of targeting this axis for HCC treatment.

Visible-Light Photocatalytic Degradation Efficiency of Tetracycline and Rhodamine B Using a Double Z-Scheme Heterojunction Catalyst of UiO-66-NH2/BiOCl/Bi2S3.

BiOCl is a promising photocatalyst, but due to its weak visible light absorption capacity and low photogenerated electron-hole pair separation rate, its practical application is limited to a certain extent. In this study, a novel double Z-scheme heterojunction UiO-66-NH2/BiOCl/Bi2S3 catalyst was constructed to broaden the visible light response range and promote high photogenerated hole-electron separation of BiOCl. Its photocatalytic performance is evaluated by dissociating tetracycline (TC) and rhodamine B (RhB) in visible light. The optimal proportion of UiO-66-NH2/BiOCl/Bi2S3 hybrids exhibits the best degradation efficiency of visible light illumination (∼93% in 120 min for TC and ∼98% in 60 min for RhB). The synergistic effect of a large visible light response range and the Z-scheme charge transfer mechanism ensure the excellent visible photocatalytic activity of UiO-66-NH2/BiOCl/Bi2S3. It is proven that h+ and •O2- are the main active substances in the photocatalysis process by active substance capture experiments and electron spin resonance tests. The intermediates and degradation processes are analyzed by high-performance liquid chromatography-mass spectrometry. This study proves that the new UiO-66-NH2/BiOCl/Bi2S3 photocatalyst has great application potential in the field of water pollution degradation and will provide a new idea for the optimization of BiOCl.

Plasma amino acid profiles in thalassaemia major with iron overload

Introduction: Iron overload in thalassaemia major patients mainly occurs due to periodic transfusions. When iron exceeds transferrin capacity, non-transferrin bound iron accumulates and causes tissue damage, including in the gastrointestinal tract, resulting in impaired enterocyte function and amino acid absorption. The aim of this study was to evaluate amino acid profiles in patients with thalassaemia major after repeated transfusions and chelation. Methods: Whole blood amino acids were analysed from dried blood spots using liquid chromatography tandem mass spectrometry. This study consisted of two parts: a cross-sectional and a cohort study in thalassaemia-β-major patients. In the cross-sectional study, amino acid profiles were analysed in 219 thalassaemia patients who received routine transfusion and chelation therapy, and 60 healthy control subjects. The cohort study included 21 subjects, from whom blood samples were taken at pre-transfusion, 1-day posttransfusion, one and three months post-chelation to evaluate changes in amino acid levels. Results: There were significant differences between amino acid levels in thalassaemia subjects and controls. Positive correlations were found between serum iron and transferrin with age, also between transferrin with proline, valine, phenylalanine, aspartic acid, and glutamic. Phenylalanine and aspartic acid were significantly lower in subjects with transferrin lower than 180 µg/dL. Significant correlations were found between haemoglobin with essential and non-essential amino acid groups. From the cohort study, significant changes were observed in glycine, alanine, leucine, and aspartic acid. Conclusion: Amino acid profiles in thalassaemia patients differed compared to healthy controls, even after transfusion and chelation. Phenylalanine and aspartic acid were significantly lower in subjects with low transferrin levels.

The Bioequivalence of Abexinostat (CRA-024781) Tosylate Tablet (20mg) in Chinese Healthy Subjects Under Fasting Conditions.

This study aimed to investigate the pharmacokinetic parameters of single oral administration of postchange and prechange abexinostat (CRA-024781) tosylate tablets in Chinese healthy subjects under fasting conditions, and assess the bioequivalence (BE) of the 2 formulations (Test [T1] and Reference [T2]). This study was a randomized, open-label, 2-formulation, fasting administration, single-dose, 2-sequence, 2-cycle, crossover BE study. Thirty-six subjects were enrolled in the study and 33 subjects completed 2 cycles. The plasma concentrations were determined by liquid chromatography-tandem mass spectrometry. The 90% confidence intervals (CIs) for the Cmax, AUC0-t, and AUC0-∞ of CRA-024781 and its 2 major metabolites (PCI-27789 and PCI-27887, both metabolites are pharmacologically inactive on HDAC1) fell within the acceptable range of 80%-125%. The results suggest that the CRA-024781 test preparation (Test [T1]) is bioequivalent to the reference preparation (Reference [T2]) in healthy Chinese subjects under fasting conditions.

Oleanolic acid induces hepatic injury by disrupting hepatocyte tight junction and dysregulation of farnesoid X receptor-mediated bile acid efflux transporters.

Oleanolic acid (OA) is a naturally occurring pentacyclic triterpene compound that has been reported to cause cholestatic liver injury. However, the regulation and pathogenic role of bile acids in OA-induced development of cholestatic liver injury remains largely unclear. Farnesoid X receptor (FXR) is a metabolic nuclear receptor that plays an important role in bile acid homeostasis in the liver by regulating efflux transporters bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2). The aim of this study was to investigate the effect of OA on hepatocyte tight junction function and determine the role of FXR, BSEP, and MRP2 in the mechanism of impairment of transport of bile acids induced by OA. Both in vivo and in vitro models were used to characterize the OA-induced liver injury. The liquid chromatography-tandem mass spectrometry (LC-MS) was employed to characterize the efflux function of the transporters, and the results showed that OA caused a blockage of bile acids efflux. OA treatment resulted in decreased expression levels of the tight junction proteins zonula occludens-1 and occludin. Immunofluorescence results showed that OA treatment significantly reduced the number of bile ducts and the immunofluorescence intensity. Pretreatment with agonists of FXR and MRP2, respectively, in animal experiments attenuated OA-induced liver injury, while pretreatment with inhibitors of BSEP and MRP2 further aggravated OA-induced liver injury. These results suggest that OA inhibits FXR-mediated BSEP and MRP2, leading to impaired bile acid efflux and disruption of tight junctions between liver cells, resulting in liver damage.

Involvement of the choroid plexus in Alzheimer’s disease pathophysiology: findings from mouse and human proteomic studies

BackgroundStructural and functional changes of the choroid plexus (ChP) have been reported in Alzheimer’s disease (AD). Nonetheless, the role of the ChP in the pathogenesis of AD remains largely unknown. We aim to unravel the relation between ChP functioning and core AD pathogenesis using a unique proteomic approach in mice and humans.MethodsWe used an APP knock-in mouse model, APPNL-G-F, exhibiting amyloid pathology, to study the association between AD brain pathology and protein changes in mouse ChP tissue and CSF using liquid chromatography mass spectrometry. Mouse proteomes were investigated at the age of 7 weeks (n = 5) and 40 weeks (n = 5). Results were compared with previously published human AD CSF proteomic data (n = 496) to identify key proteins and pathways associated with ChP changes in AD.ResultsChP tissue proteome was dysregulated in APPNL-G-F mice relative to wild-type mice at both 7 and 40 weeks. At both ages, ChP tissue proteomic changes were associated with epithelial cells, mitochondria, protein modification, extracellular matrix and lipids. Nonetheless, some ChP tissue proteomic changes were different across the disease trajectory; pathways related to lysosomal function, endocytosis, protein formation, actin and complement were uniquely dysregulated at 7 weeks, while pathways associated with nervous system, immune system, protein degradation and vascular system were uniquely dysregulated at 40 weeks. CSF proteomics in both mice and humans showed similar ChP-related dysregulated pathways.ConclusionsTogether, our findings support the hypothesis of ChP dysfunction in AD. These ChP changes were related to amyloid pathology. Therefore, the ChP could become a novel promising therapeutic target for AD.

Phytochemicals as eco-friendly corrosion inhibitors for mild steel in sulfuric acid solutions: a review

Abstract Plant extracts represent abundant sources of biomolecules distributed throughout various plant parts. These biomolecules are extracted using diverse solvents and methods. Within these plant extracts lie bioactive compounds, known for their antioxidant properties and anticorrosive capabilities. Detecting and isolating these active biomolecules from plant extracts necessitates analytical techniques such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. The active biomolecules within plant extracts contain heteroatoms within their structures, facilitating their adsorption on steel surfaces and conferring corrosion inhibition properties. The advantages of plant extracts as green corrosion inhibitors include ready availability, ease of application, eco-friendly characteristics, and cost-effectiveness. These extracts adhere to steel surfaces, blocking their active sites and effectively reducing the corrosion rate. This review consolidates the findings on the corrosion inhibition potential of plant extracts from various plant parts, elucidating their performance in different concentrations of sulfuric acid.