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Genomics control of biostimulant-induced stress tolerance and crop yield enhancement.

Biostimulants are changing modern agriculture, as they have the potential to secure healthy and sustainable food production while preserving the environment. They have two main biological effects: growth promotion and stress protection. Both effects can lead to enhancement of the yield and improvement of the marketable grade of the produce in crops, without compromising crop quality. Their use increased exponentially in the past decade, as they are highly efficient, ecologically friendly (non-toxic, biodegradable), and applicable to all major crops. While exponential data on the physiological mechanisms of stress protection is accumulating in recent years, the information as to how biostimulants act at the molecular level is still rather limited. Here we review the growing evidence of the biostimulants role in stress protection and yield enhancement of crops, as well as the recent transcriptomic and metabolomic data, which indicate biostimulants' molecular mode of action. In particular, we outline the role of genes encoding signaling components, plant hormones (abscisic acid, brassinosteroids, and ethylene), genes encoding transcription factors from ERF, WRKY, NAC, and MYB families, and genes related to growth, photosynthesis, and stress response. Finally, we describe strategies to study the genetic and genomics control of biostimulants mode of action, with foci on stress tolerance and yield enhancement. In Arabidopsis, established systems for biostimulants-induced protection against drought and oxidative stress will allow both forward and reverse genetics approaches to identify key genes from the biostimulants network. Mutations in such genes compromise the stress-protective effect of biostimulants. In major crops such as pepper and tomato, large Genome Wide Association Studies (GWAS) panels can be utilized to study crops responses to biostimulants in terms of drought tolerance, fruit qualities, and yield in order to pinpoint genes controlling biostimulants-induced stress protection and yield enhancement. The combination of these approaches allows identification and verification of important genes involved in the pathways of biostimulant-induced stress protection and yield enhancement, as well as deciphering parts of the intricate biostimulant-signaling network.

Crops, Agricultural↗

Integrated Multiomics Analyses of the Molecular Landscape of Sarcopenia in Alcohol-Related Liver Disease.

BACKGROUND: Skeletal muscle is a major target for ethanol-induced perturbations, leading to sarcopenia in alcohol-related liver disease (ALD). The complex interactions and pathways involved in adaptive and maladaptive responses to ethanol in skeletal muscle are not well understood. Unlike hypothesis-driven experiments, an integrated multiomics-experimental validation approach provides a comprehensive view of these interactions. METHODS: We performed multiomics analyses with experimental validation to identify novel regulatory mechanisms of sarcopenia in ALD. Studies were done in a comprehensive array of models including ethanol-treated (ET) murine and human-induced pluripotent stem cell-derived myotubes (hiPSCm), skeletal muscle from a mouse model of ALD (mALD) and human patients with alcohol-related cirrhosis and controls. We generated 13 untargeted datasets, including chromatin accessibility (assay for transposase accessible chromatin), RNA sequencing, proteomics, phosphoproteomics, acetylomics and metabolomics, and conducted integrated multiomics analyses using UpSet plots and feature extraction. Key findings were validated using immunoblots, redox measurements (NAD+/NADH ratio), imaging and senescence-associated molecular phenotype (SAMP) assays. Mechanistic studies included mitochondrial-targeted Lactobacillus brevis NADH oxidase (MitoLbNOX) to increase redox ratio and MitoTempo as a mitochondrial free radical scavenger. RESULTS: Multiomics analyses revealed enrichment in mitochondrial oxidative function, protein synthesis and senescence pathways consistent with the known effects of hypoxia-inducible factor 1&#x3b1; (HIF1&#x3b1;) during normoxia. Across preclinical and clinical models, HIF1&#x3b1; targets (n&#x2009;=&#x2009;32 genes) and signalling genes (n&#x2009;>&#x2009;100 genes) (n&#x2009;=&#x2009;3 ATACseq, n&#x2009;=&#x2009;65 phosphoproteomics, n&#x2009;=&#x2009;10 acetylomics, n&#x2009;=&#x2009;6 C2C12 proteomics, n&#x2009;=&#x2009;106 C2C12 RNAseq, n&#x2009;=&#x2009;64 hiPSC RNAseq, n&#x2009;=&#x2009;30 hiPSC proteomics, n&#x2009;=&#x2009;3 mouse proteomics, n&#x2009;=&#x2009;25 mouse RNAseq, n&#x2009;=&#x2009;8 human RNAseq, n&#x2009;=&#x2009;3 human proteomics) were increased. Stabilization of HIF1&#x3b1; (C2C12, 6hEtOH 0.24&#x2009;&#xb1;&#x2009;0.09; p&#x2009;=&#x2009;0.043; mALD 0.32&#x2009;&#xb1;&#x2009;0.074; p&#x2009;=&#x2009;0.005; data shown as mean difference&#x2009;&#xb1;&#x2009;standard error mean) was accompanied by enrichment in the early transient and late change clusters, -log(p-value)&#x2009;=&#x2009;1.5-3.8, of the HIF1&#x3b1; signalling pathway. Redox ratio was reduced in ET myotubes (C2C12: 15512&#x2009;&#xb1;&#x2009;872.1, p&#x2009;<&#x2009;0.001) and mALD muscle, with decreased expression of electron transport chain components (CI-V, p&#x2009;<&#x2009;0.05) and Sirt3 (C2C12: 0.067&#x2009;&#xb1;&#x2009;0.023, p&#x2009;=&#x2009;0.025; mALD: 0.41&#x2009;&#xb1;&#x2009;0.12, p&#x2009;=&#x2009;0.013). Acetylation of mitochondrial proteins was increased in both models (C2C12: 107364&#x2009;&#xb1;&#x2009;4558, p&#x2009;=&#x2009;0.03; mALD: 40036&#x2009;&#xb1;&#x2009;18&#x2009;987, p&#x2009;=&#x2009;0.049). Ethanol-induced SAMP was observed across models (P16: C2C12: 0.2845&#x2009;&#xb1;&#x2009;0.1145, p&#x2009;<&#x2009;0.05; hiPSCm: 0.2591, p&#x2009;=&#x2009;0.041). MitoLbNOX treatment reversed redox imbalance, HIF1&#x3b1; stabilization, global acetylation and myostatin expression (p&#x2009;<&#x2009;0.05). CONCLUSIONS: An integrated multiomics approach, combined with experimental validation, identifies HIF1&#x3b1; stabilization and accelerated post-mitotic senescence as novel mechanisms of sarcopenia in ALD. These findings show the complex molecular interactions leading to mitochondrial dysfunction and progressive sarcopenia in ALD.

Sarcopenia↗

Integrative cross-tissue transcriptome-wide association and metabolomic analysis reveals novel genetic risk loci for aortic aneurysm.

BACKGROUND: Aortic aneurysm (AA) is a life-threatening cardiovascular condition with a strong genetic component, however, its molecular mechanisms remain poorly understood. Although genome-wide association studies (GWAS) have identified numerous risk loci, most prior studies have investigated genetic and metabolic factors separately, leaving the causal pathways from genetic variants to disease largely unexplored. METHODS: We established an integrative framework combining cross-tissue transcriptome-wide association studies (TWAS) with metabolomic mediation analysis. First, we integrated GWAS data from FinnGen R12 with multi-tissue expression quantitative trait loci (eQTL) data from Genotype-Tissue Expression Project (GTEx) V8, then performed cross-tissue TWAS using the Unified Test for MOlecular SignaTures (UTMOST) and single-tissue validation with the Functional Summary-based Imputation (FUSION) to prioritize susceptibility genes. Second, we applied Mendelian randomization (MR), colocalization, and Fine-mapping Of CaUsal gene Sets (FOCUS) to assess causality and identify high-confidence genes. Third, we performed metabolite mediation analysis to uncover metabolic pathways linking genetic variants to disease risk. Finally, we validated key findings in mouse models of thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) using Quantitative Real-Time Reverse Transcription Polymerase Chain Reaction (RT-qPCR) and Western blotting. RESULTS: We identified multiple novel susceptibility genes for AA and its subtypes. Key genes included ADH family members (ADH1A, ADH1B, ADH4, ADH6) and ZNF827, which showed cross-subtype associations with strong colocalization evidence in vascular tissues. Metabolite mediation analysis revealed significant pathways involving N-acetylphenylalanine and methionine sulfoxide. Functional enrichment revealed distinct biological mechanisms: AA and AAA were primarily associated with metabolic pathways, whereas TAA-related genes were enriched in developmental and contractile processes. PheWAS indicated no significant off-target associations. Critically, experimental validation in mouse models confirmed significant upregulation of ZNF827 in TAA and ADH6 in AAA at both mRNA and protein levels, corroborating the genetic predictions. CONCLUSION: This integrated cross-omics analysis identifies novel genetic loci and, crucially, uncovers specific nutrient-related metabolic pathways that mediate genetic risk. These findings provide a mechanistic basis for future nutritional and metabolic intervention studies in AA and its subtypes.

MAGMA↗

Comparison of rapid liquid chromatography-electrospray ionization-tandem mass spectrometry methods for determination of glycoalkaloids in transgenic field-grown potatoes.

Two rapid methods for highly selective detection and quantification of the two major glycoalkaloids in potatoes, alpha-chaconine and alpha-solanine, were compared for robustness in high-throughput operations for over 1000 analytical runs using potato tuber samples from field trials. Glycoalkaloids were analyzed using liquid chromatography coupled to tandem mass spectrometry in multiple reaction monitoring mode. An electrospray interface was used in the detection of glycoalkaloids in positive ion mode. Classical reversed phase (RP) and hydrophilic interaction (HILIC) columns were investigated for chromatographic separation, ruggedness, recovery, precision, and accuracy. During the validation procedure both methods proved to be precise and accurate enough in relation to the high degree of endogenous biological variability found for field-grown potato tubers. However, the RP method was found to be more precise, more accurate, and, more importantly, more rugged than the HILIC method for maintaining the analytes' peak shape symmetry in high-throughput operation. When applied to the comparison of six classically bred potato cultivars to six genetically modified (GM) lines engineered to synthesize health beneficial inulins, the glycoalkaloid content in potato peels of all GM lines was found within the range of the six cultivars. We suggest complementing current unbiased metabolomic strategies by validating quantitative analytical methods for important target analytes such as the toxic glycoalkaloids in potato plants.

Agriculture↗

A high-performance liquid chromatography-tandem mass spectrometry method for quantitation of nitrogen-containing intracellular metabolites.

A comprehensive method of quantifying intracellular metabolite concentrations would be a valuable addition to the arsenal of tools for holistic biochemical studies. Here, we describe a step toward the development of such method: a quantitative assay for 90 nitrogen-containing cellular metabolites. The assay involves reverse-phase high-performance liquid chromatography separation followed by electrospray ionization and detection of the resulting ions using triple-quadrupole mass spectrometry in selected reaction monitoring mode. For 79 of the 90 metabolites, the assay is linear with a limit of detection of 10 ng/mL or less. Using this method, 36 metabolites can be reliably detected in extracts of the bacterium Salmonella enterica, with the identity of each metabolite confirmed by the presence, on growing of the bacteria in (13)C-glucose, of a peak corresponding to the isotope-labeled form of the compound. Quantitation in biological samples is performed by mixing unlabeled test cell extract with (13)C-labeled standard extract, and determining the (12)C/(13)C-ratio for each metabolite. Using this approach, the metabolomes of growing (exponential phase) and carbon-starved (stationary phase) bacteria were compared, revealing 16 metabolites that are significantly down-regulated and five metabolites that are significantly up-regulated, in stationary phase.

Bacteria↗

Observing and interpreting correlations in metabolomic networks.

MOTIVATION: Metabolite profiling aims at an unbiased identification and quantification of all the metabolites present in a biological sample. Based on their pair-wise correlations, the data obtained from metabolomic experiments are organized into metabolic correlation networks and the key challenge is to deduce unknown pathways based on the observed correlations. However, the data generated is fundamentally different from traditional biological measurements and thus the analysis is often restricted to rather pragmatic approaches, such as data mining tools, to discriminate between different metabolic phenotypes. METHODS AND RESULTS: We investigate to what extent the data generated networks reflect the structure of the underlying biochemical pathways. The purpose of this work is 2-fold: Based on the theory of stochastic systems, we first introduce a framework which shows that the emergent correlations can be interpreted as a 'fingerprint' of the underlying biophysical system. This result leads to a systematic relationship between observed correlation networks and the underlying biochemical pathways. In a second step, we investigate to what extent our result is applicable to the problem of reverse engineering, i.e. to recover the underlying enzymatic reaction network from data. The implications of our findings for other bioinformatics approaches are discussed.

Algorithms↗

Metabolomic profiling of natural volatiles: headspace trapping: GC-MS.

Plants are a fabulously rich source of naturally volatile metabolites, which are derived from a range of contrasting biochemical pathways (e.g., mono-, di-, and sesquiterpenoids, benzoates, alcohols, esters). Such volatiles may immediately be released from the plant or they may be stored, e.g., in glycosylated form for release later "on demand." Certain roles for these molecules have already been determined in that they can function as attractants (e.g., to pollinators, seed dispersers, and others) or as protectants (repellants, pathogen inhibitors, and so on). The flavor and fragrance of plant materials to humans and other animals are also, to a great extent, determined by natural volatiles. Other more sophisticated roles have also been elucidated where plant volatiles have been shown to be involved either as signal molecules to attract the predators of damaging herbivorous insects or potentially even as signal molecules warning other plants of imminent danger. As such, detailed knowledge of these components can be valuable in relation to breeding crop varieties for enhanced product quality or for achieving improved resistance to pathogens and insects. Furthermore, knowledge of the metabolites can result in a corresponding knowledge of the genes responsible for their synthesis and this can lead to dedicated strategies for their in vitro production through, e.g., reverse genetics in heterologous microbial expression systems in fermentors for the production of high-value fine chemicals. Various analytical techniques based on gas chromatography-mass spectrometry have been devised for the analysis of this complex group of metabolites. Two of these key methods are detailed in this chapter.

Arabidopsis↗

A multiplex quantitation method for eicosanoids and platelet-activating factor using column-switching reversed-phase liquid chromatography-tandem mass spectrometry.

Eicosanoids and platelet-activating factor (PAF) are phospholipid-derived lipid mediators produced by various tissues and cells through a cascade pathway. For a comprehensive analysis of these lipid mediators, a simultaneous quantitation method with sensitivity and reliability is necessary. This article details a development of column-switching reversed-phase liquid chromatography-tandem mass spectrometry for multiplex quantitation of eicosanoids and PAF. The adsorptive nature of lipids caused significant loss of signal in a conventional column-switching configuration. The use of an online-dilution method allowed use of 100% methanol as a sample solvent, which prevented sample adsorption to contacting surfaces. Addition of 0.2% formic acid to the sample solvent was required for the successful introduction of LTC4 to the trapping column and minimizing its carryover. The optimized method provided rapid analysis of 14 lipid mediators with a throughput of 96 samples/24 h, lower limits of quantitation of 5 pg on column, and linear calibration ranges up to 2000-5000 pg. The system was highly compatible with solid-phase-extracted samples, as methanol-eluted fractions were directly injected without reconstitution. The analysis of lipid mediator production of macrophage-like RAW264.7 cells demonstrated that the cell-based assay can be performed in a 96-well format, suitable for metabolomics analyses and/or screening strategies.

Animals↗

Changes in the metabolome of Saccharomyces cerevisiae associated with evolution in aerobic glucose-limited chemostats.

The effect of culture age on intra- and extracellular metabolite levels as well as on in vitro determined specific activities of enzymes of central carbon metabolism was investigated during evolution for over 90 generations of Saccharomyces cerevisiae CEN.PK 113-7D in an aerobic glucose/ethanol-limited chemostat at a specific dilution rate of 0.052 h(-1). It was found that the fluxes of consumed (O2, glucose/ethanol) and secreted compounds (CO2) did not change significantly during the entire cultivation period. However, morphological changes were observed, leading to an increased cellular surface area. During 90 generations of chemostat growth not only the residual glucose concentration decreased, also the intracellular concentrations of trehalose, glycolytic intermediates, TCA cycle intermediates and amino acids were found to have decreased with a factor 5-10. The only exception was glyoxylate which showed a fivefold increase in concentration. In addition to this the specific activities of most glycolytic enzymes also decreased by a factor 5-10 during long-term cultivation. Exceptions to this were hexokinase, phosphofructokinase, pyruvate kinase and 6-phosphogluconate dehydrogenase of which the activities remained unchanged. Furthermore, the concentrations of the adenylate nucleotides as well as the energy charge of the cells did not change in a significant manner. Surprisingly, the specific activities of glucose-6-phosphate dehydrogenase (G6PDH), malate synthase (MS) and isocitrate lyase (ICL) increased significantly during 90 generations of chemostat cultivation. These changes seem to indicate a pattern where metabolic overcapacities (for reversible reactions) and storage pools (trehalose, high levels of amino acids and excess protein in enzymes) are lost during the evolution period. The driving force is proposed to be a growth advantage in the absence of these metabolic overcapacities.

Adaptation, Physiological↗

Bioinformatics for cancer management in the post-genome era.

Human cancer is caused by multiple factors, such as genetic predisposition, chronic persistent inflammation, environmental factors, life style, and aging. Dysregulated proliferation, dysregulated adhesion, resistance to apoptosis, resistance to senescence, and resistance to anti-cancer drugs are features of cancer cells. Accumulation of multiple epigenetic changes and genetic alterations of cancer-associated genes during multi-stage carcinogenesis results in more malignant phenotypes. Post-genome science is characterized by omics data related to genome, transcriptome, proteome, metabolome, interactome, and epigenome as well as by high-throughput technology, such as whole-genome tiling oligonucleotide array, array CGH with 32,433 overlapping BAC clones, transcriptome microarray, mass spectrometry, tissue-based expression array, and cell-based transfection array. Benchtop oncology supplies Desktop oncology with large amounts of omics data produced by high-throughput technology. Desktop oncology establishes knowledge on cancer-related biomarkers, such as predisposition markers, diagnostic markers, prognostic markers, and therapeutic markers, by using bioinformatics and human intelligence of experts for data mining and text mining. Bedside oncology applies the knowledge established by Desktop oncology to determine therapeutics for cancer patients. Antibody drugs (Trastuzumab/Herceptin, Cetuximab/Erbitux, Bevacizumab/Avastin, et cetera), small molecule inhibitors for tyrosine kinases (Gefitinib/Iressa, Erlotinib/Tarceva, Imatinib/Gleevec, et cetera), conventional cytotoxic drugs, and anti-hormonal drugs are used for cancer chemotherapy. Biomarker monitoring contributes to therapeutic optional choice and drug dosage determination for cancer patients. Knowledge on biomarkers is feedforwarded from desktop to bedside in the translational research, and then biomarker monitoring is feedbacked from bedside to desktop in the reverse translational research. Desktop oncology is indispensable for cancer research in the post-genome era. Combination of genetic screening for cancer predisposition in the general population and precise selection of therapeutic options during cancer management could contribute to the realization of personalized prevention and to dramatically improve the prognosis of cancer patients in the future.

Antineoplastic Agents↗

Lipid utilization, gluconeogenesis, and seedling growth in Arabidopsis mutants lacking the glyoxylate cycle enzyme malate synthase.

The aim of this research was to test the role of the glyoxylate cycle enzyme malate synthase (MLS) in lipid utilization, gluconeogenesis, and seedling growth in Arabidopsis. We hypothesized that in the absence of MLS, succinate produced by isocitrate lyase (ICL) could still feed into the tricarboxylic acid cycle, whereas glyoxylate could be converted to sugars using enzymes of the photorespiratory pathway. To test this hypothesis we isolated knock-out mls mutants and studied their growth and metabolism in comparison to wild type and icl mutant seedlings. In contrast to icl seedlings, which grow slowly and are unable to convert lipid into sugars (Eastmond, P. J., Germain, V., Lange, P. R., Bryce, J. H., Smith, S. M. & Graham, I. A. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 5669-5674), mls seedlings grow faster, use their lipid more rapidly, and are better able to establish as plantlets. Transcriptome and metabolome analyses show that icl seedlings exhibit many features characteristic of carbohydrate starvation, whereas mls seedlings differ relatively little from wild type. In the light mls seedlings generate more sugars than icl seedlings, and when fed with [14C]acetate, 14C-labeling of sugars is three times greater than in icl seedlings and more than half that in wild type seedlings. The mls seedlings also accumulate more glycine and serine than icl or wild type seedlings, consistent with a diversion of glyoxylate into these intermediates of the photorespiratory pathway. We conclude that, in contrast to bacteria and fungi in which MLS is essential for gluconeogenesis from acetate or fatty acids, MLS is partially dispensable for lipid utilization and gluconeogenesis in Arabidopsis seedlings.

Arabidopsis↗

Molecular phenotyping of the pal1 and pal2 mutants of Arabidopsis thaliana reveals far-reaching consequences on phenylpropanoid, amino acid, and carbohydrate metabolism.

The first enzyme of the phenylpropanoid pathway, Phe ammonia-lyase (PAL), is encoded by four genes in Arabidopsis thaliana. Whereas PAL function is well established in various plants, an insight into the functional significance of individual gene family members is lacking. We show that in the absence of clear phenotypic alterations in the Arabidopsis pal1 and pal2 single mutants and with limited phenotypic alterations in the pal1 pal2 double mutant, significant modifications occur in the transcriptome and metabolome of the pal mutants. The disruption of PAL led to transcriptomic adaptation of components of the phenylpropanoid biosynthesis, carbohydrate metabolism, and amino acid metabolism, revealing complex interactions at the level of gene expression between these pathways. Corresponding biochemical changes included a decrease in the three major flavonol glycosides, glycosylated vanillic acid, scopolin, and two novel feruloyl malates coupled to coniferyl alcohol. Moreover, Phe overaccumulated in the double mutant, and the levels of many other amino acids were significantly imbalanced. The lignin content was significantly reduced, and the syringyl/guaiacyl ratio of lignin monomers had increased. Together, from the molecular phenotype, common and specific functions of PAL1 and PAL2 are delineated, and PAL1 is qualified as being more important for the generation of phenylpropanoids.

Amino Acids↗

The causal relationship between genetically predicted blood metabolites and idiopathic pulmonary fibrosis: A bidirectional two-sample Mendelian randomization study.

BACKGROUND: Numerous metabolomic studies have confirmed the pivotal role of metabolic abnormalities in the development of idiopathic pulmonary fibrosis (IPF). Nevertheless, there is a lack of evidence on the causal relationship between circulating metabolites and the risk of IPF. METHODS: The potential causality between 486 blood metabolites and IPF was determined through a bidirectional two-sample Mendelian randomization (TSMR) analysis. A genome-wide association study (GWAS) involving 7,824 participants was performed to analyze metabolite data, and a GWAS meta-analysis involving 6,257 IPF cases and 947,616 control European subjects was conducted to analyze IPF data. The TSMR analysis was performed primarily with the inverse variance weighted model, supplemented by weighted mode, MR-Egger regression, and weighted median estimators. A battery of sensitivity analyses was performed, including horizontal pleiotropy assessment, heterogeneity test, Steiger test, and leave-one-out analysis. Furthermore, replication analysis and meta-analysis were conducted with another GWAS dataset of IPF containing 4,125 IPF cases and 20,464 control subjects. Mediation analyses were used to identify the mediating role of confounders in the effect of metabolites on IPF. RESULTS: There were four metabolites associated with the elevated risk of IPF, namely glucose (odds ratio [OR] = 2.49, 95% confidence interval [95%CI] = 1.13-5.49, P = 0.024), urea (OR = 6.24, 95% CI = 1.77-22.02, P = 0.004), guanosine (OR = 1.57, 95%CI = 1.07-2.30, P = 0.021), and ADpSGEGDFXAEGGGVR (OR = 1.70, 95%CI = 1.00-2.88, P = 0.0496). Of note, the effect of guanosine on IPF was found to be mediated by gastroesophageal reflux disease. Reverse Mendelian randomization analysis displayed that IPF might slightly elevate guanosine levels in the blood. CONCLUSION: Conclusively, hyperglycemia may confer a promoting effect on IPF, highlighting that attention should be paid to the relationship between diabetes and IPF, not solely to the diagnosis of diabetes. Additionally, urea, guanosine, and ADpSGEGDFXAEGGGVR also facilitate the development of IPF. This study may provide a reference for analyzing the potential mechanism of IPF and carry implications for the prevention and treatment of IPF.

Humans↗

The early responses of Arabidopsis thaliana cells to cadmium exposure explored by protein and metabolite profiling analyses.

To get more insight into plant cell response to cadmium (Cd) stress, both proteomic and metabolomic "differential display" analyses were performed on Arabidopsis thaliana cells exposed to different concentrations of the toxic chemical. After a 24 h treatment, soluble proteins extracted from untreated and treated cells were separated by 2-D-PAGE and image analyses were performed to quantify and compare protein levels. Proteins up- and down-regulated in response to Cd were identified by MS and mapped into specific metabolic pathways and cellular processes, highlighting probable activation of the carbon, nitrogen, and sulfur metabolic pathways. For some of these proteins, Northern blot and RT-PCR analyses were performed to test transcript accumulation in response to Cd. In parallel, metabolite profiling analyses by LC coupled to ESI MS were initiated to better characterize the metabolic adaptation to the chemical stress. This study revealed that the main variation at the metabolite level came from the presence of six different families of phytochelatins, in A. thaliana cells treated with Cd, whose accumulation increases with Cd concentrations. Taken together these data provide an overview of the molecular and cellular changes elicited by Cd exposure.

Amino Acids↗

Glycolysis-dependent reactive oxygen species mediate desmopressin acetate-induced rescue of platelet dysfunction caused by antiplatelet therapy.

Antiplatelet therapy is extensively used in the prevention and treatment of cardiovascular and cerebrovascular diseases; however, life-threatening hemorrhage requires urgent reversal of platelet dysfunction. Desmopressin acetate has been proposed as a rescue strategy, yet its efficacy and underlying mechanisms remain incompletely understood, particularly regarding redox regulation. A mouse carotid artery blood flow injury model was employed to evaluate the effects of desmopressin acetate on platelet and coagulation dysfunction induced by antiplatelet therapy. Proteomic analyses were performed in both patients and mice to identify differentially expressed proteins. Genetic knockout and pharmacological inhibition approaches were used to investigate the mechanistic pathways involved. Desmopressin acetate effectively restored platelet function and coagulation capacity in antiplatelet-treated mice. Proteomic profiling identified peroxiredoxin-5, a key antioxidant enzyme, as significantly upregulated following antiplatelet therapy but markedly downregulated after desmopressin acetate administration; these findings were validated in plasma samples from 10 patients who received dual antiplatelet therapy for unruptured intracranial aneurysms. Functional studies demonstrated that proteomic profiling identified peroxiredoxin-5 supplementation impaired platelet function, whereas proteomic profiling identified peroxiredoxin-5 knockout or inhibition significantly improved platelet activity. Notably, desmopressin acetate primarily suppressed liver-derived proteomic profiling identified peroxiredoxin-5 expression. Mechanistically, desmopressin acetate enhanced platelet glycolysis via phosphofructokinase-2/fructose-2,6-bisphosphatase 3 activation, leading to increased intracellular reactive oxygen species levels. Inhibition of phosphofructokinase-2/fructose-2,6-bisphosphatase 3 attenuated glycolysis, reduced reactive oxygen species generation, and restored proteomic profiling identified peroxiredoxin-5 expression, thereby abolishing the platelet-rescuing effects of desmopressin acetate. Desmopressin acetate rescued platelet dysfunction induced by antiplatelet therapy through a glycolysis-reactive oxygen species-proteomic profiling identified peroxiredoxin-5 axis, in which glycolysis-driven reactive oxygen species generation plays a central regulatory role. These findings indicate redox modulation as a critical mechanism underlying desmopressin acetate-mediated platelet rescue and suggest a potential therapeutic strategy for managing severe bleeding associated with antiplatelet therapy.

Animals↗

Hepatic gene expression profiling using Genechips in zebrafish exposed to 17alpha-ethynylestradiol.

Genomic, proteomic, and metabolomic technologies continue to receive increasing interest from environmental toxicologists. This interest is due to the great potential of these technologies to identify detailed modes of action and to provide assistance in the evaluation of a contaminant's risk to aquatic organisms. Our experimental model is the zebrafish (Danio rerio) exposed to reference endocrine disrupting compounds in order to investigate compound-induced changes in gene transcript profiles. Adult, female zebrafish were exposed to 0, 15, 40, and 100ng/L of 17alpha-ethynylestradiol (EE2) and concentration and time-dependent changes in hepatic gene expression were examined using Affymetrix GeneChip Zebrafish Genome Microarrays. At 24, 48, and 168h, fish were sacrificed and liver mRNA was extracted for gene expression analysis (24 and 168h only). In an effort to link gene expression changes to effects on higher levels of biological organization, body and ovary weights were measured and blood was collected for measurement of plasma steroid hormones (17beta-estradiol (E2), testosterone (T)) and vitellogenin (VTG) using ELISA. EE2 exposure significantly affected gene expression, GSI, E2, T, and VTG. We observed 1622 genes that were significantly affected (p< or =0.001) in a concentration-dependent manner by EE2 exposure at either 24 or 168h. Gene ontology (GO) analysis revealed that EE2 exposure affected genes involved in hormone metabolism, vitamin A metabolism, steroid binding, sterol metabolism, and cell growth. Plasma VTG was significantly increased at 24, 48, and 168h (p< or =0.05) at 40 and 100ng/L and at 15ng/L at 168h. E2 and T were significantly reduced following EE2 exposure at 48 and 168h. GSI was decreased in a concentration-dependent manner at 168h. In this study, we identified genes involved in a variety of biological processes that have the potential to be used as markers of exposure to estrogenic substances. Future work will evaluate the use of these genes in zebrafish exposed to weak estrogens to determine if these genes are indicative of exposure to estrogens with varying potencies.

Animals↗