PubMed HealthSearch

SEARCH · PubMed Health

Results for “AA metabolic pathway”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

10 recordsLinked to original sources

Spike protein-induced VSIR-ISX signaling disrupts metabolic homeostasis and promotes COVID-19-related immune dysfunction.

COVID-19 has caused millions of deaths worldwide since 2019. Vaccination has reduced both transmission and disease severity. However, emerging viral variants have weakened vaccine effectiveness, highlighting the need for new antiviral therapies. This study examines how the SARS-CoV-2-Spike protein (SARS-2-S) induces the VSIR-ISX signaling pathway, leading to metabolic disturbances that may worsen disease progression. Using RNA sequencing, we found that SARS-2-S expression in pulmonary cells activates genes involved in tryptophan and arachidonic acid (AA) metabolism, altering bioactive mediators like kynurenine and prostanoids, which are crucial for inflammation and immune responses. Mechanistically, the ACE2-MYD88 pathway, activated by SARS-2-S, enhances the VSIR-ISX axis through NF-κB signaling, driving these metabolic disruptions. Chromatin immunoprecipitation and genome sequencing revealed that ISX, activated via VSIR-MAPK signaling, upregulates enzymes involved in AA metabolism by binding directly to their gene promoters. Notably, disrupting the VSIR-ISX axis using shRNA interference or NF-κB inhibitors effectively mitigated these metabolic disturbances. Our findings suggest that the VSIR-ISX pathway could be a promising therapeutic target for treating COVID-19 by addressing virus-induced metabolic disruptions.

Humans

Pathways of arachidonic acid metabolism and modulation by drugs.

The AA cascade in addition to producing various oxygenation products concomitantly yields an oxygen radical. This oxidant selectively deactivates the cyclooxygenase, peroxidase and PGI2 synthetase components whereas TXA2 synthetase is resistant to this oxidant. On the basis of available data it is not possible to assign an inflammatory inducing role to this oxidant on the basis of these actions. Other loci of action must be involved. Among the possibilities are the elements involved in the release of arachidonic acid. Studies relating to this possibility are examined in this report.

Animals

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

Amaryllidaceae Alkaloids and Isoquinoline Alkaloids: A Perspective on Historical Approaches to Pathway Elucidation.

Alkaloid biosynthesis is a central topic in plant specialized metabolism because many alkaloids have ecological, pharmacological, and biotechnological relevance. Isoquinoline alkaloids (IAs) and Amaryllidaceae alkaloids (AAs) are both connected to aromatic amino acid metabolism, but they differ in taxonomic distribution, scaffold-forming chemistry, pathway resolution, and biotechnological development. This review compares the historical and methodological trajectories that have shaped IA and AA pathway elucidation, from compound isolation, radiotracer experiments, and biochemical inference to transcriptomics, metabolomics, functional enzymology, isotope-guided active-tissue identification, regulatory studies, and heterologous pathway reconstruction. In IAs, especially benzylisoquinoline alkaloids, broad genomic and transcriptomic resources have supported candidate gene discovery and functional characterization of several branches, including morphinan, protoberberine, benzophenanthridine, and aporphine-related pathways. In contrast, AA biosynthesis has advanced more recently through function-driven approaches that clarified key steps such as N4OMT-mediated 4'-O-methylation, NBS/NR-mediated norbelladine formation, CYP96T-dependent regioselective oxidative coupling, and transient reconstruction of major scaffold-forming branches. Remaining gaps include the unresolved enzymatic formation of 3,4-dihydroxybenzaldehyde in AAs and incomplete functional validation across less-studied IA scaffold classes. By integrating biochemical logic, omics-guided discovery, enzyme evolution, tissue specificity, regulation, and synthetic biology, this review identifies priorities for future alkaloid pathway discovery and sustainable production.

3,4-dihydroxybenzaldehyde

Effect of inhibitors of arachidonic acid metabolism on mitogenesis in human lymphocytes: possible role of thromboxanes and products of the lipoxygenase pathway.

Although it is already known that prostaglandins inhibit lymphocyte responses to mitogens the role of other products of arachidonic acid (AA) metabolism has not previously been investigated. Various inhibitors of AA metabolism were studied for their effects on mitogenesis in human lymphocytes, including imidazole, benzylimidazole, N-0164, L-8027, 5, 8, 11, 14 eicosatetraynoic acid, nordihydroguaiaretic acid, indomethacin, and aspirin. Selective or partially selective inhibitors of thromboxane synthesis, such as imidazole, benzylimidazole, N-0164, and L-8027 inhibited the mitogenic response at concentrations that also substantially affect thromboxane B2 synthesis in platelet-free lymphocyte preparations. Since indomethacin failed to reverse the inhibition by imidazole or N-0164, it is probably due to decreased thromboxane synthesis per se rather than secondary increases in prostaglandin synthesis. Eicosatetraynoic acid and nordihydroguaiaretic acid were more effective inhibitors of mitogenesis than of thromboxane synthesis. Since these agents also affect the lipoxygenase pathway, it is possible that part of their action is at this level. Thus, in addition to the inhibitory effects of prostaglandins on mitogenesis, other products of AA metabolism may promote the response.

Antilymphocyte Serum

Multi-omics and spatial transcriptomics reveal that S100A10 drives CD8+ T-cell exhaustion and immune evasion in hepatocellular carcinoma through cPLA2-5-LOX-mediated arachidonic acid metabolism and ferroptosis.

Immune evasion in hepatocellular carcinoma (HCC) represents a major biological barrier limiting the efficacy of immunotherapy, yet its molecular basis remains incompletely understood. Increasing evidence indicates that tumor metabolic reprogramming and ferroptosis-related signaling play critical roles in shaping an immunosuppressive tumor microenvironment (TME); however, the specific regulatory factors involved remain unclear. This study aims to systematically elucidate the functional role of S100 calcium-binding protein A10 (S100A10) in immune evasion in HCC, with a particular focus on the molecular mechanisms by which S100A10 regulates CD8+ T-cell exhaustion through arachidonic acid (AA) metabolism and ferroptosis, as well as its potential therapeutic implications. To this end, data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) cohort are integrated to analyze the expression patterns of S100A10, its prognostic value, and its association with the immune microenvironment. S100A10 overexpression and knockout models are established in HCCLM3 and MHCC97L cell lines, and S100A10-mediated metabolic pathway reprogramming is characterized using transcriptomic profiling, untargeted metabolomics, and ferroptosis-related functional assays. In parallel, single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics are employed to delineate the cell-type specificity and spatial distribution of S100A10. Furthermore, human CD8+ T-cell co-culture systems and orthotopic mouse HCC models are used to evaluate the impact of S100A10 on immune function and responsiveness to anti-programmed cell death protein 1 (anti-PD-1) therapy. The results demonstrate that S100A10 is significantly upregulated in HCC and is closely associated with poor prognosis and an immunosuppressive state. Mechanistically, S100A10 activates cytosolic phospholipase A2-arachidonate 5-lipoxygenase (cPLA2-5-LOX)-mediated AA oxidative metabolism, leading to the accumulation of lipid peroxidation products and ferroptosis-associated signals, thereby driving CD8+ T-cell exhaustion and promoting immune evasion. Significantly, inhibition of S100A10 reshapes the tumor immune microenvironment (TIME) and enhances the therapeutic efficacy of anti-PD-1 treatment. Collectively, these findings identify S100A10 as a critical regulator of metabolic-immune coupling in HCC and provide a theoretical basis for combinatorial strategies targeting metabolism and immunotherapy.

Arachidonic acid metabolism

Comparative Analysis of Volatile Compounds, Amino Acids, Fatty Acids, and Lipidomic Profiles in Thigh Muscles of Commercial Arbor Acres (AA) Broilers and Indigenous Chengkou and Langshan Chickens.

Flavor-related compounds and nutritional components of chicken meat vary among different breeds, but comprehensive comparisons of these characteristics between commercial and indigenous chickens remain insufficiently characterized. In this study, three chicken breeds (Arbor Acres, Chengkou, and Langshan) were slaughtered at their respective market ages, and the volatile flavor compounds, amino acids, fatty acids, and lipidomic profiles of thigh muscle were analyzed to investigate breed-associated differences in flavor-related and nutritional characteristics. Langshan chickens exhibited the highest total volatile compound content and also had the highest total amino acid levels, with significantly higher contents of umami and sweet amino acids. In addition, both indigenous breeds showed higher levels of arachidonic acid (C20:4n6) than Arbor Acres broilers, while Chengkou chickens had the highest content of docosahexaenoic acid (DHA, C22:6n3). Lipidomic analysis identified 787 lipids, with glycerophospholipids and sphingolipids as the predominant classes. Differential lipid analysis revealed that Langshan chickens had 38 upregulated lipids compared with Arbor Acres chickens, while Chengkou chickens exhibited 258 differential lipids relative to Arbor Acres chickens. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that these differential lipids were mainly associated with glycerolipid, sphingolipid, and glycerophospholipid metabolism. Correlation analysis further revealed significant associations between specific lipids and flavor-related compounds, amino acids, and fatty acids, suggesting their potential roles in breed-associated differences. Overall, this study demonstrates that indigenous chicken breeds possess distinct flavor-related and nutritional profiles compared with commercial Arbor Acres broilers and provides valuable insights into breed-associated differences in chicken meat characteristics.

amino acids

Insights on the pathogenesis of type 2 diabetes as revealed by signature genomic classifiers in an African American population in the Washington, DC area.

AIMS: African Americans (AA) in the United States have a high risk of type 2 diabetes mellitus (T2DM) and suffer from disparities in the prevalence, mortality, and comorbidities of the disease compared to other Americans. The present study aimed to shed light on the molecular mechanisms of disease pathogenesis of T2DM among AA in the Washington, DC region. METHODS: We performed TaqMan Low Density Arrays (TLDA) on 24 genes of interest that belong to three categories: metabolic disease and disorders, cancer-related genes, and neurobehavioural disorders genes. The 18 genes, viz. ARNT, CYP2D6, IL6, INSR, RRAD, SLC2A2 (metabolic disease and disorders), APC, BCL2, CSNK1D, MYC, SOD2, TP53 (Cancer-related), APBA1, APBB2, APOC1, APOE, GSK3B, and NAE1 (neurobehavioural disorders), were differentially expressed in T2DM participants compared to controls. RESULTS: Our results suggest that factors including gender, smoking habits, and the severity or lack of control of T2DM (as indicated by HbA1c levels) were significantly associated with differential gene expression. APBA1 was significantly (p-value <0.05) downregulated in all diabetes participants. Upregulation of APOE and CYP2D6 genes and downregulation of the INSR gene were observed in the majority of diabetes patients. CONCLUSIONS: Tobacco smoking and gender were significantly associated with case-control differences in expression of the APBA1 and APOE genes (connected with Alzheimer's disease) and the INSR and CYP2D6 (associated with metabolic disorders). The results highlight the need for more effective management of T2DM and for tobacco smoking cessation interventions in this community, and further research on the associations of T2DM with other disease processes, including cancer and neurobehavioral pathways.

Humans

Metabolic Dysregulation of the Lysophospholipid/Autotaxin Axis in the Chromosome 9p21 Gene SNP rs10757274.

BACKGROUND: Common chromosome 9p21 single nucleotide polymorphisms (SNPs) increase coronary heart disease risk, independent of traditional lipid risk factors. However, lipids comprise large numbers of structurally related molecules not measured in traditional risk measurements, and many have inflammatory bioactivities. Here, we applied lipidomic and genomic approaches to 3 model systems to characterize lipid metabolic changes in common Chr9p21 SNPs, which confer &#x2248;30% elevated coronary heart disease risk associated with altered expression of ANRIL, a long ncRNA. METHODS: Untargeted and targeted lipidomics was applied to plasma from NPHSII (Northwick Park Heart Study II) homozygotes for AA or GG in rs10757274, followed by correlation and network analysis. To identify candidate genes, transcriptomic data from shRNA downregulation of ANRIL in HEK-293 cells was mined. Transcriptional data from vascular smooth muscle cells differentiated from induced pluripotent stem cells of individuals with/without Chr9p21 risk, nonrisk alleles, and corresponding knockout isogenic lines were next examined. Last, an in-silico analysis of miRNAs was conducted to identify how ANRIL might control lysoPL (lysophosphospholipid)/lysoPA (lysophosphatidic acid) genes. RESULTS: Elevated risk GG correlated with reduced lysoPLs, lysoPA, and ATX (autotaxin). Five other risk SNPs did not show this phenotype. LysoPL-lysoPA interconversion was uncoupled from ATX in GG plasma, suggesting metabolic dysregulation. Significantly altered expression of several lysoPL/lysoPA metabolizing enzymes was found in HEK cells lacking ANRIL. In the vascular smooth muscle cells data set, the presence of risk alleles associated with altered expression of several lysoPL/lysoPA enzymes. Deletion of the risk locus reversed the expression of several lysoPL/lysoPA genes to nonrisk haplotype levels. Genes that were altered across both cell data sets were DGKA, MBOAT2, PLPP1, and LPL. The in-silico analysis identified 4 ANRIL-regulated miRNAs that control lysoPL genes as miR-186-3p, miR-34a-3p, miR-122-5p, and miR-34a-5p. CONCLUSIONS: A Chr9p21 risk SNP associates with complex alterations in immune-bioactive phospholipids and their metabolism. Lipid metabolites and genomic pathways associated with coronary heart disease pathogenesis in Chr9p21 and ANRIL-associated disease are demonstrated.

Chromosomes, Human, Pair 9

Transcriptomic profiling across stages of non-muscle-invasive bladder cancer identifies fibroblast activation protein-alpha as a stromal biomarker associated with progression.

BACKGROUND: T1 non-muscle-invasive bladder cancer (NMIBC) represents a biologically aggressive subgroup with substantial heterogeneity in recurrence and progression risk. Current clinicopathological risk stratification tools lack sufficient precision to identify patients at the highest risk of progression to muscle-invasive bladder cancer (MIBC). OBJECTIVE: To characterize transcriptomic differences between T1 and&#x2009;<&#x2009;T1 (Ta/Tis) NMIBC and to explore the association of fibroblast activation protein-&#x3b1; (FAP) gene expression with disease progression. METHODS: Transcriptomic profiling was performed on formalin-fixed paraffin-embedded (FFPE) tumor tissue from 66 patients with primary, treatment-na&#xef;ve NMIBC and 5 patients with T2 disease (included for exploratory comparisons). Analyses included differential gene expression, gene set enrichment analysis (GSEA), molecular subtyping, immune cell deconvolution, and evaluation of FAP expression in relation to recurrence and progression. External validation of FAP was conducted in three independent NMIBC cohorts. RESULTS: T1 tumors demonstrated a distinct transcriptomic profile compared with&#x2009;<&#x2009;T1 tumors, characterized by enrichment of cell cycle-related and metabolic pathways and a higher prevalence of aggressive molecular subtypes. Despite these molecular differences, no statistically significant differences in recurrence-free, progression-free, cancer-specific, and overall survival were observed, likely reflecting limited event numbers. Among recurrent tumors, early recurrences (&#x2264;&#x2009;24&#xa0;months) were associated with epithelial-mesenchymal transition signatures. FAP expression increased with tumor stage (p&#x2009;=&#x2009;0.0005) and was associated with progression (p&#x2009;=&#x2009;0.002) and mortality (p&#x2009;=&#x2009;0.01). Patients with tumors in the highest quartile of FAP expression had worse progression-free survival. This association was consistently observed in three external NMIBC cohorts. CONCLUSIONS: T1 NMIBC exhibits distinct transcriptomic features suggestive of increased biological aggressiveness. Elevated FAP expression is reproducibly associated with progression risk across multiple cohorts, supporting its potential role as a biomarker of aggressive disease. Given the limited number of progression events, these findings should be considered hypothesis-generating and warrant prospective validation before clinical implementation.

Humans