SEARCH · PubMed Health

Results for “Polyamines”

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.

14 recordsLinked to original sources

PubMed2026

Unveiling crosstalk regulations within the polyamine pathway and between polyamine and purine pathways in Aedes aegypti females.

We previously demonstrated that ornithine decarboxylase (ODC) deficiency critically impairs nitrogen metabolism and survival in Aedes aegypti. To further examine the role of the polyamine pathway in Ae. aegypti nitrogen metabolism, we evaluated the expression of three additional genes encoding proteins involved in the biosynthetic pathway: S-adenosylmethionine decarboxylase, spermidine synthase (SdS), spermine synthase (SmS), and seven genes encoding proteins involved in the catabolic pathway in fat body, midgut and Malpighian tubules by qPCR. Distinct transcriptional profiles were observed in mosquito tissues during the first gonotrophic cycle. SdS and SmS showed a differential protein expression pattern in fat body of sugar- and blood-fed mosquitoes. Genetic silencing of SdS, SmS or SdS and SmS by RNA interference (RNAi) decreased female survival. Mosquitoes with SdS or SmS deficiency exhibited a reduction of 5G1 trypsin level in the midgut at 24 h post-blood meal (PBM) , a delay in blood digestion, and a decrease in uric acid concentration in the excreta at 48 h PBM. RNAi-mediated SdS knockdown also caused a decrease in SmS protein level and vice-versa, RNAi-driven SmS deficiency resulted in a decrease in SdS protein abundance. Notably, ODC knockdown reduced SdS, SmS, xanthine dehydrogenase-1 protein levels, and decreased specific metabolite concentrations in fat body at 24 h PBM. In addition, RNAi-mediated ODC, SdS and SmS knockdown impacted transcript levels of genes involved in polyamine and purine pathways in fat body at 24 h PBM. Our findings uncover unique crosstalk regulations within the polyamine pathway and between polyamine and purine pathways.

Ammonia metabolism↗

PubMed2026

Polyamines buffer labile iron to suppress ferroptosis.

Polyamines are essential and evolutionarily conserved metabolites present at millimolar concentrations in mammalian cells. Cells tightly regulate polyamine homeostasis through complex feedback mechanisms, yet the precise role necessitating this regulation remains unclear. Here, we show that polyamines contribute to endogenous buffering of redox-active iron, providing a molecular link between polyamine metabolism and ferroptosis. Using a genome-wide CRISPR screen, we identified a synthetic lethal dependency between polyamine depletion and the key ferroptosis suppressor, glutathione peroxidase 4 (GPX4). Mechanistically, we show that polyamine deficiency triggers a redistribution of cellular iron, increasing the labile iron pool and upregulating ferritin. To directly visualize this iron buffering in living cells, we developed a genetically encoded fluorescent reporter for redox-active iron. Live-cell analysis revealed a striking inverse correlation between intracellular polyamine levels and redox-active iron at single-cell resolution. These findings reposition polyamines as key regulators of iron homeostasis, with implications for ferroptosis-linked disease states and cellular redox balance.

Ferroptosis↗

PubMed2025

Polyamines buffer labile iron to suppress ferroptosis.

Polyamines are essential and evolutionarily conserved metabolites present at millimolar concentrations in mammalian cells. Cells tightly regulate polyamine homeostasis through complex feedback mechanisms, yet the precise role necessitating this regulation remains unclear. Here, we show that polyamines function as endogenous buffers of redox-active iron, providing a molecular link between polyamine metabolism and ferroptosis. Using genome-wide CRISPR screens, we identified a synthetic lethal dependency between polyamine depletion and the key ferroptosis suppressor, GPX4. Mechanistically, we show that polyamine deficiency triggers a redistribution of cellular iron, increasing the labile iron pool and upregulating ferritin. To directly visualize this iron buffering in living cells, we developed a genetically encoded fluorescent reporter for redox-active iron. Live-cell analysis revealed a striking inverse correlation between intracellular polyamine levels and redox-active iron at single-cell resolution. These findings reposition polyamines as key regulators of iron homeostasis, with implications for ferroptosis-linked disease states and cellular redox balance.

Journal Article↗

PubMed2026

Polyamine Metabolism as a Metabolic Vulnerability in Prostate Cancer Treated with Supraphysiological Androgens.

Prostate cancer progression is predominantly driven by androgen receptor (AR) signaling, and despite initial benefits of androgen deprivation therapy (ADT), most patients eventually develop lethal castration-resistant disease. Cyclic administration of supraphysiologic androgen (SPA) with ADT paradoxically suppresses tumor growth; however, responses are heterogeneous, and the mechanisms underlying the antitumor effects of SPA remain incompletely understood. In this issue of Cancer Research, Kumar and colleagues demonstrate that SPA induces a distinct metabolic response, characterized by AR-dependent induction of polyamine biosynthesis via ODC1 and AMD1. This metabolic rewiring elevates polyamine synthesis while concurrently depleting the methyl donor S-adenosylmethionine (SAM). Although increased polyamine metabolism by SPA may promote adaptive resistance, genetic or pharmacologic inhibition of ODC1 using difluoromethylornithine (DFMO) enhances SPA-induced growth suppression by disrupting protective polyamine pools and further exacerbating SAM depletion, revealing a metabolic vulnerability in SPA-treated prostate cancer cells. Supporting these findings, a clinical trial combining DFMO with bipolar androgen therapy (BAT) demonstrated reduced circulating polyamines in patients, confirming polyamine pathway suppression in patients with different genomic features. Together, this study uncovers a mechanistic link among androgen signaling, polyamine metabolism, and therapeutic response, providing a rationale for targeting metabolic dependencies to improve SPA efficacy. See related article by Kumar et al., p. 1148.

Male↗

PubMed2025

Reprogramming neuroblastoma by diet-enhanced polyamine depletion.

Neuroblastoma is a highly lethal childhood tumour derived from differentiation-arrested neural crest cells1,2. Like all cancers, its growth is fuelled by metabolites obtained from either circulation or local biosynthesis3,4. Neuroblastomas depend on local polyamine biosynthesis, and the inhibitor difluoromethylornithine has shown clinical activity5. Here we show that such inhibition can be augmented by dietary restriction of upstream amino acid substrates, leading to disruption of oncogenic protein translation, tumour differentiation and profound survival gains in the Th-MYCN mouse model. Specifically, an arginine- and proline-free diet decreases the amount of the polyamine precursor ornithine and enhances tumour polyamine depletion by difluoromethylornithine. This polyamine depletion causes ribosome stalling, unexpectedly specifically at codons with adenosine in the third position. Such codons are selectively enriched in cell cycle genes and low in neuronal differentiation genes. Thus, impaired translation of these codons, induced by combined dietary and pharmacological intervention, favours a pro-differentiation proteome. These results suggest that the genes of specific cellular programmes have evolved hallmark codon usage preferences that enable coherent translational rewiring in response to metabolic stresses, and that this process can be targeted to activate differentiation of paediatric cancers.

Animals↗

PubMed2026

eIF5A and polyamines restrict mRNA levels in response to ribosome stalls.

Obstacles to translation elongation stall ribosomes and allow deleterious proteins to accumulate, which threatens cellular health. Cells recognize and clear stalled ribosomes via several interrelated pathways, although the mechanisms by which cells distinguish stalled from normally elongating ribosomes and mount an appropriate response are incompletely understood. While recent work highlights how ribosome collisions help cells to recognize stalled ribosomes, how other factors contribute to detection remains unclear. Here, we report a requirement for the translational factor eIF5A in the mRNA decay response to ribosomal stalling, i.e., No-Go mRNA Decay (NGD). We identified the Caenorhabditis elegans polyamine transporter, catp-6, via a forward genetic screen as a factor required for NGD. During our mechanistic dissection of the catp-6 phenotype, we uncovered a role for cellular polyamines and the translation elongation factor eIF5A in NGD, and we show this requirement is conserved from C. elegans to Saccharomyces cerevisiae. Our analyses support the idea that cells use eIF5A to identify ribosomal stalls and execute NGD and uncover a molecular function for a core protein synthesis factor in limiting expression from stall-inducing mRNAs. Our work offers insight into how cells identify and remove problematic mRNAs from the translational pool. Our work also raises the possibility that dysregulated mRNA decay is an unrecognized pathophysiology associated with polyaminopathies and eIF5A disorders, of relevance to varied neurodegenerative and aging phenotypes and efforts to pharmacologically inhibit eIF5A.

Animals↗

PubMed2025

Genome-Wide Identification, Phylogenetic Analysis, and Expression Pattern of Polyamine Biosynthesis Gene Family in Pepper.

Polyamines (PAs), including putrescine, spermidine, spermine, and thermospermine, play essential roles in plant growth, development, and responses to stress. However, the structure and function of PA biosynthetic genes in pepper remain poorly characterized. This study aimed to identify PA biosynthesis genes in the pepper genome using bioinformatics approaches and to assess their expression under various stress conditions. A total of 16 PA biosynthesis-related genes were identified, representing members of the arginine decarboxylase (ADC), ornithine decarboxylase (ODC), agmatine iminohydrolase (AIH), N-carbamoylputrescine amidohydrolase (CPA), S-adenosylmethionine decarboxylase (SAMDC), spermidine synthase (SPDS), spermine synthase (SPMS), and ACAULIS5 (ACL5) gene families. These genes encode proteins with an average molecular weight of approximately 40 kDa, primarily localized in the mitochondria and cytoplasm. Promoter analysis revealed multiple cis-acting elements associated with stress and phytohormone responsiveness. Gene expression was induced by various abiotic stresses, including saline-alkaline, drought, heat, cold, and hydrogen peroxide, as well as by phytohormones such as abscisic acid, ethylene, salicylic acid, auxin, and gibberellin. Overall, this study provides a comprehensive analysis of PA biosynthesis genes in pepper and highlights their potential roles in stress adaptation and hormone signalling, offering a foundation for further exploration of PA-mediated stress tolerance mechanisms.

Capsicum↗

PubMed2025

The Pseudomonas aeruginosa Type VI secretion system toxin Tse8 evolved from a novel N-carbamoylputrescine amidohydrolase.

The polyamine putrescine is synthesized primarily from L-arginine via agmatine in bacteria. There are currently three known routes from agmatine to putrescine, including direct conversion by agmatinase. The other two routes use agmatine deiminase to produce N-carbamoylputrescine from agmatine, then one of two nonhomologous enzymes, putrescine transcarbamylase or N-carbamoylputrescine amidohydrolase (NCPAH), converts N-carbamoylputrescine to putrescine. Here, we functionally identify enzymes from phylogenetically distant bacteria, the ɣ-proteobacterium Shewanella oneidensis, and the actinomycetota species Microterricola gilva, that are novel alternative, nonhomologous, noncanonical NCPAHs that we term AguY, which have emerged by convergent evolution. Kinetic analysis indicates that the AguY enzymes are as efficient as the canonical NCPAH from Pseudomonas aeruginosa in converting N-carbamoylputrescine to putrescine. Genomic evidence suggests that the AguY enzymes may participate in putrescine biosynthetic or agmatine catabolic pathways and are occasionally encoded in genomes that also encode agmatinase. We show that the Type VI secretion system toxin Tse8 from P. aeruginosa has evolved from AguY. It is formally possible that AguY evolved directly or indirectly from the ancient glutamine amidohydrolase GatA, a component of the transamidosome, an RNA/protein complex required for the production of glutamine-charged tRNA. Our study provides a further example of the prevalence of convergent evolution and horizontal gene transfer in polyamine biosynthesis, suggesting pervasive selective pressure to evolve polyamine metabolism in bacteria.

Pseudomonas aeruginosa↗

PubMed2026

Genomic determinants underlying biogenic amine detoxification phenotypes in food-associated lactic acid bacteria: Mechanism, evolutionary origin, and relevance to fermented food safety.

Biogenic amines (BAs) are toxic metabolites that accumulate in fermented foods and pose significant food safety concerns. Although several lactic acid bacteria (LAB) have previously been reported to exhibit strain-specific BA-degrading phenotypes, the genetic determinants underlying these activities have remained largely uncharacterized. Here, we analyzed 8251 LAB genomes to validate BA-degrading phenotypes. We predicted five BA-associated genes, including two direct biogenic amine-degrading genes (BADGs), mco and patA, and three polyamine-modifying genes (PMGs), speG, paiA, and bltD. Among BADGs, mco was broadly distributed across LAB and strongly enriched across food-associated niches. patA, organized within a conserved potD-glnB-potABC-patA cassette, is a putative, functionally distinct BADG in LAB, revealing a nitrogen-responsive polyamine uptake-catabolism module. Phylogenomics, phylogenetic reconciliation, and synteny analysis established that all five genes entered the LAB through episodic horizontal gene transfer followed by lineage-specific fixation. GC compositional bias and mobile genetic element association further corroborated the horizontal origin of the two BADGs. Structural analysis confirmed the conservation of catalytic core residues of BADGs across LAB, indicating strong purifying selection. Phenotype-to-genotype correlation with experimentally reported LAB suggested mco as a reliable genomic predictor of degrading phenotype. Integration of degradation and biosynthetic profiles predicted multiple LAB species capable of both synthesizing and degrading BA, along with 1823 genomes with degradation potential but lacking detectable BA biosynthesis genes. This study provides the first large-scale genome framework linking BA-degrading phenotypes with their genetic determinants in LAB and offers a rational basis for selecting BA-detoxifying strains for fermented food applications.

Biogenic Amines↗

PubMed2026

Multimodal analysis of CD38 in T-cell Acute Lymphoblastic Leukemia Identifies Combinatorial Therapeutic Strategies.

Outcomes for pediatric patients with refractory or relapsed T-cell acute lymphoblastic leukemia (T-ALL) are poor, underscoring the need for improved therapeutic strategies. CD38, a type II transmembrane glycoprotein, is a promising target in T-ALL, with clinical trials evaluating CD38-targeting immunotherapies in frontline and relapsed settings. However, the biological role of CD38 in T-ALL has not been systematically defined. We interrogated CD38 biology through multimodal profiling of pediatric T-ALL samples. Bulk RNA sequencing of 1,335 primary tumors revealed that CD38 expression varies across genomic and immunophenotypic subtypes in T-ALL. Flow cytometry of 150 primary samples and CITE-sequencing of 40 cases demonstrated broad surface expression of CD38. A transcription factor CRISPR-screen identified RUNX1, RUNX3, and TP53 as candidate positive regulators of CD38. Metabolomic profiling of cell lines further revealed disruption of the polyamine pathway following CD38 perturbation. Supporting this finding, co-targeting CD38 with difluoromethylornithine (DFMO), a polyamine metabolism disruptor, improved survival in preclinical models. Across transcriptomic datasets, including primary tumors, cell lines, and patient-derived xenograft models, IL32 expression consistently decreased following CD38 loss or negativity, supporting an association between CD38 and inflammatory signaling pathways. Additionally, CD38 and LCK expression were positively correlated across majority of genomic subtypes, implicating SRC kinase signaling. Consistent with this, daratumumab in cell lines increased LCK phosphorylation, and combination therapy with dasatinib improved survival compared to monotherapy. Collectively, these findings define previously unrecognized interactions between CD38 and targetable pathways and genes in T-ALL and identify rational combinatorial strategies to enhance CD38-directed therapies and reduce relapse risk.

Journal Article↗

PubMed2024

A metabolomics pipeline highlights microbial metabolism in bloodstream infections.

The growth of antimicrobial resistance (AMR) highlights an urgent need to identify bacterial pathogenic functions that may be targets for clinical intervention. Although severe infections profoundly alter host metabolism, prior studies have largely ignored microbial metabolism in this context. Here, we describe an iterative, comparative metabolomics pipeline to uncover microbial metabolic features in the complex setting of a host and apply it to investigate gram-negative bloodstream infection (BSI) in patients. We find elevated levels of bacterially derived acetylated polyamines during BSI and discover the enzyme responsible for their production (SpeG). Blocking SpeG activity reduces bacterial proliferation and slows pathogenesis. Reduction of SpeG activity also enhances bacterial membrane permeability and increases intracellular antibiotic accumulation, allowing us to overcome AMR in culture and in vivo. This study highlights how tools to study pathogen metabolism in the natural context of infection can reveal and prioritize therapeutic strategies for addressing challenging infections.

Metabolomics↗

PubMed2026

Selection favors cost-ordered adaptive mutational paths in a stress-magnitude-dependent manner.

Chronic exposure to stress requires adaptive strategies beyond canonical regulatory mechanisms. Stress varies, both qualitatively and quantitatively, across physiological niches and exerts distinct selection pressures on colonizing bacteria. Bacteria employ diverse defense strategies to withstand various stressful conditions, yet how they tailor their responses to different magnitudes of the same stressor remains poorly understood. We used multiple adaptive laboratory evolution experiments of Escherichia coli across varying paraquat concentrations and genetic backgrounds to dissect adaptive strategies at different levels of stress. Integrating multi-omic analyses with a tailored genome-scale metabolic model-based parametrized cost calculations, we identify two fundamentally distinct tolerance mechanisms. Under low-paraquat stress, blocking the polyamine transporter that is reported to be hijacked for paraquat influx suffices to maintain optimal growth. In contrast, higher stress levels activate an energetically demanding program involving enhanced detoxification and efflux. The transport flux regulation establishes a primary defense layer, upon which metabolic repair systems provide additional fitness advantages. The stress magnitude-dependent differential engagement of previously reported paraquat tolerance approaches offers insights into the principles governing dynamic bacterial adaptation.

Journal Article↗

PubMed2026

Integrated multi-omics analysis reveals a pH-driven metabolic and translational switch in Ureaplasma parvum.

Human ureaplasmas are minimal-genome bacteria and pathobionts of the urogenital tract. They must adapt to fluctuating pH conditions despite the absence of canonical transcriptional regulatory systems. However, the mechanisms underlying these responses remain unclear. This study aimed to construct a system-level model of pH adaptation in this minimal pathogen. We used an integrated multi-omics platform combining proteomics, metabolomics, and RNA modification profiling to construct a system-level model of pH adaptation. The results revealed a bifurcated strategy governed by the differential activation of preexisting, co-regulated functional modules. Under neutral pH conditions (pH 7), Ureaplasma parvum activated energy metabolism and upregulated ATP synthesis while forming a stress-counteracting proteostasis pathway. This may suggest a biological energy state under high stress conditions. Conversely, under acidic stress (pH 5), it activated biosynthesis/translation, showing significant upregulation of ribosomal proteins and accumulation of translation precursors and the polyamine spermidine. This may represent a state of expanded translational capacity. This adaptive switch is accompanied by dynamic reorganization of the epitranscriptome, highlighting the importance of post-transcriptional regulation. This study suggests mechanisms by which minimal organisms achieve adaptive plasticity through sophisticated post-transcriptional and metabolic control, providing a new framework for understanding Ureaplasma physiology and the biology of genome-reduced organisms.IMPORTANCEMinimal bacteria challenge canonical views of cellular regulation. In organisms with radically reduced genomes and sparse transcription factors, how adaptive plasticity is achieved remains a core question. Our study proposes a model in which a simple physicochemical cue-extracellular pH-selects among prewired cellular programs, while post-transcriptional and epitranscriptomic layers fine-tune execution. The findings of this study suggest a multi-omics scheme for how organisms adapt to environmental changes and ensure survival without inducing new circuits or complex transcriptional regulation. Conceptually, it proposes regulation via RNA modifications in processes, such as metabolism, proteostasis, and translation. This framework may be generalizable to other genome-reduced microorganisms. Beyond microbiology, it provides design principles for synthetic biology and offers a mechanistic interpretation of phenotypic tolerance to stress factors. It may encourage the use of pH-linked epitranscriptome signals as measurable indicators of cellular state.

Hydrogen-Ion Concentration↗

PubMed2026

Multi-omics analysis to uncover constitutive priming and dynamic metabolic reprogramming conferring white rust resistance in Brassica juncea.

White rust, caused by Albugo candida, is one of the most devastating diseases of Indian mustard (Brassica juncea), causing yield losses of up to 90%. Durable resistance sources within cultivated Brassica germplasm remain limited. In this study, near-isogenic lines (NILs) of B. juncea cv. Varuna harbouring resistance from an East European source (Donskaja-IV, possessing a single CC-NB-LRR protein-coding R gene) was used to investigate the molecular basis of resistance through integrated transcriptomic and metabolomic analyses at 48 and 96 hours post-inoculation (hpi). Transcriptomic profiling revealed that the resistant Varuna_WRR line exhibited significantly higher unique transcript expression (18.76%) compared to the susceptible parent (8.41%) during the progression of infection. Principal component analysis showed clear separation between genotypes based on infection status, time, and genetic background. In the resistant line, upregulated genes were enriched in ethylene-activated signaling, protein phosphorylation, endoplasmic reticulum stress response, pectin biosynthesis, and hypersensitive response at 48 hpi, shifting toward programmed cell death, protein ubiquitination, abscisic acid metabolism, and starch biosynthesis at 96 hpi. Conversely, the susceptible line displayed broad downregulation of primary metabolic processes, indicating metabolic exhaustion. Metabolomic analysis demonstrated that the resistant genotype accumulated higher levels of defense-related amino acids (proline, glutamine, glutamic acid, serine, threonine, glycine), carbohydrates, organic acids, and polyamines, supporting enhanced nitrogen assimilation, energy reserves, membrane stability, and signaling. Together, these findings indicate that constitutive priming and dynamic activation of defense signaling, protein turnover, and osmoprotectant accumulation underpin the enhanced resistance in Varuna_WRR against Albugo candida. This integrated multi-omics approach provides valuable insights for breeding durable white rust resistance in Brassica juncea.

Brassica juncea↗