RESUMO
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.
Assuntos
Metabolômica , Poliaminas , Humanos , Animais , Poliaminas/metabolismo , Camundongos , Bacteriemia/microbiologia , Bacteriemia/metabolismo , Bacteriemia/tratamento farmacológico , Antibacterianos/farmacologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/metabolismo , FemininoRESUMO
The repertoire of modifications to bile acids and related steroidal lipids by host and microbial metabolism remains incompletely characterized. To address this knowledge gap, we created a reusable resource of tandem mass spectrometry (MS/MS) spectra by filtering 1.2 billion publicly available MS/MS spectra for bile-acid-selective ion patterns. Thousands of modifications are distributed throughout animal and human bodies as well as microbial cultures. We employed this MS/MS library to identify polyamine bile amidates, prevalent in carnivores. They are present in humans, and their levels alter with a diet change from a Mediterranean to a typical American diet. This work highlights the existence of many more bile acid modifications than previously recognized and the value of leveraging public large-scale untargeted metabolomics data to discover metabolites. The availability of a modification-centric bile acid MS/MS library will inform future studies investigating bile acid roles in health and disease.
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Ácidos e Sais Biliares , Microbioma Gastrointestinal , Metabolômica , Espectrometria de Massas em Tandem , Animais , Humanos , Ácidos e Sais Biliares/química , Metabolômica/métodos , Poliaminas , Espectrometria de Massas em Tandem/métodos , Bases de Dados de Compostos QuímicosRESUMO
The polyamines putrescine, spermidine, and spermine are abundant polycations of vital importance in mammalian cells. Their cellular levels are tightly regulated by degradation and synthesis, as well as by uptake and export. Here, we discuss the delicate balance between the neuroprotective and neurotoxic effects of polyamines in the context of Parkinson's disease (PD). Polyamine levels decline with aging and are altered in patients with PD, whereas recent mechanistic studies on ATP13A2 (PARK9) demonstrated a driving role of a disturbed polyamine homeostasis in PD. Polyamines affect pathways in PD pathogenesis, such as α-synuclein aggregation, and influence PD-related processes like autophagy, heavy metal toxicity, oxidative stress, neuroinflammation, and lysosomal/mitochondrial dysfunction. We formulate outstanding research questions regarding the role of polyamines in PD, their potential as PD biomarkers, and possible therapeutic strategies for PD targeting polyamine homeostasis.
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Doença de Parkinson , Transtornos Parkinsonianos , Animais , Humanos , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Poliaminas/metabolismo , Neuroproteção , Espermidina/metabolismo , Mamíferos/metabolismoRESUMO
Polyamine synthesis represents one of the most profound metabolic changes during T cell activation, but the biological implications of this are scarcely known. Here, we show that polyamine metabolism is a fundamental process governing the ability of CD4+ helper T cells (TH) to polarize into different functional fates. Deficiency in ornithine decarboxylase, a crucial enzyme for polyamine synthesis, results in a severe failure of CD4+ T cells to adopt correct subset specification, underscored by ectopic expression of multiple cytokines and lineage-defining transcription factors across TH cell subsets. Polyamines control TH differentiation by providing substrates for deoxyhypusine synthase, which synthesizes the amino acid hypusine, and mice in which T cells are deficient for hypusine develop severe intestinal inflammatory disease. Polyamine-hypusine deficiency caused widespread epigenetic remodeling driven by alterations in histone acetylation and a re-wired tricarboxylic acid (TCA) cycle. Thus, polyamine metabolism is critical for maintaining the epigenome to focus TH cell subset fidelity.
Assuntos
Linhagem da Célula , Poliaminas/metabolismo , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Polaridade Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromatina/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Colite/imunologia , Colite/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Epigenoma , Histonas/metabolismo , Inflamação/imunologia , Inflamação/patologia , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/metabolismo , Lisina/análogos & derivados , Lisina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Ornitina Descarboxilase/metabolismo , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Fatores de Transcrição/metabolismoRESUMO
Metabolism is a major regulator of immune cell function, but it remains difficult to study the metabolic status of individual cells. Here, we present Compass, an algorithm to characterize cellular metabolic states based on single-cell RNA sequencing and flux balance analysis. We applied Compass to associate metabolic states with T helper 17 (Th17) functional variability (pathogenic potential) and recovered a metabolic switch between glycolysis and fatty acid oxidation, akin to known Th17/regulatory T cell (Treg) differences, which we validated by metabolic assays. Compass also predicted that Th17 pathogenicity was associated with arginine and downstream polyamine metabolism. Indeed, polyamine-related enzyme expression was enhanced in pathogenic Th17 and suppressed in Treg cells. Chemical and genetic perturbation of polyamine metabolism inhibited Th17 cytokines, promoted Foxp3 expression, and remodeled the transcriptome and epigenome of Th17 cells toward a Treg-like state. In vivo perturbations of the polyamine pathway altered the phenotype of encephalitogenic T cells and attenuated tissue inflammation in CNS autoimmunity.
Assuntos
Autoimunidade/imunologia , Modelos Biológicos , Células Th17/imunologia , Acetiltransferases/metabolismo , Trifosfato de Adenosina/metabolismo , Aerobiose/efeitos dos fármacos , Algoritmos , Animais , Autoimunidade/efeitos dos fármacos , Cromatina/metabolismo , Ciclo do Ácido Cítrico/efeitos dos fármacos , Citocinas/metabolismo , Eflornitina/farmacologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Epigenoma , Ácidos Graxos/metabolismo , Glicólise/efeitos dos fármacos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Camundongos Endogâmicos C57BL , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Oxirredução/efeitos dos fármacos , Putrescina/metabolismo , Análise de Célula Única , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th17/efeitos dos fármacos , Transcriptoma/genéticaRESUMO
Enteric-associated neurons (EANs) are closely associated with immune cells and continuously monitor and modulate homeostatic intestinal functions, including motility and nutrient sensing. Bidirectional interactions between neuronal and immune cells are altered during disease processes such as neurodegeneration or irritable bowel syndrome. We investigated the effects of infection-induced inflammation on intrinsic EANs (iEANs) and the role of intestinal muscularis macrophages (MMs) in this context. Using murine models of enteric infections, we observed long-term gastrointestinal symptoms, including reduced motility and loss of excitatory iEANs, which was mediated by a Nlrp6- and Casp11-dependent mechanism, depended on infection history, and could be reversed by manipulation of the microbiota. MMs responded to luminal infection by upregulating a neuroprotective program via ß2-adrenergic receptor (ß2-AR) signaling and mediated neuronal protection through an arginase 1-polyamine axis. Our results identify a mechanism of neuronal death post-infection and point to a role for tissue-resident MMs in limiting neuronal damage.
Assuntos
Mucosa Intestinal/imunologia , Macrófagos/imunologia , Receptores Adrenérgicos beta 2/metabolismo , Adrenérgicos , Animais , Arginase/metabolismo , Caspases Iniciadoras/imunologia , Caspases Iniciadoras/metabolismo , Sistema Nervoso Entérico/imunologia , Sistema Nervoso Entérico/metabolismo , Feminino , Gastroenteropatias , Microbioma Gastrointestinal , Infecções , Inflamação/imunologia , Mucosa Intestinal/metabolismo , Intestino Delgado/imunologia , Intestinos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microbiota , Neurônios/fisiologia , Receptores Adrenérgicos beta 2/imunologia , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Transdução de SinaisRESUMO
Psoriasis is a chronic inflammatory disease whose etiology is multifactorial. The contributions of cellular metabolism to psoriasis are unclear. Here, we report that interleukin-17 (IL-17) downregulated Protein Phosphatase 6 (PP6) in psoriatic keratinocytes, causing phosphorylation and activation of the transcription factor C/EBP-ß and subsequent generation of arginase-1. Mice lacking Pp6 in keratinocytes were predisposed to psoriasis-like skin inflammation. Accumulation of arginase-1 in Pp6-deficient keratinocytes drove polyamine production from the urea cycle. Polyamines protected self-RNA released by psoriatic keratinocytes from degradation and facilitated the endocytosis of self-RNA by myeloid dendritic cells to promote toll-like receptor-7 (TLR7)-dependent RNA sensing and IL-6 production. An arginase inhibitor improved skin inflammation in murine and non-human primate models of psoriasis. Our findings suggest that urea cycle hyperreactivity and excessive polyamine generation in psoriatic keratinocytes promote self-RNA sensation and PP6 deregulation in keratinocytes is a pivotal event that amplifies the inflammatory circuits in psoriasis.
Assuntos
Células Dendríticas/imunologia , Queratinócitos/metabolismo , Fosfoproteínas Fosfatases/deficiência , Poliaminas/metabolismo , Psoríase/patologia , RNA/imunologia , Células 3T3 , Animais , Arginase/antagonistas & inibidores , Arginase/metabolismo , Arginina/metabolismo , Autoantígenos/imunologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Células HEK293 , Células HaCaT , Humanos , Interleucina-17/metabolismo , Macaca fascicularis , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fosfoproteínas Fosfatases/genética , Fosforilação , Pele/patologia , Receptor 7 Toll-Like/imunologiaRESUMO
Translation initiation is typically restricted to AUG codons, and scanning eukaryotic ribosomes inefficiently recognize near-cognate codons. We show that queuing of scanning ribosomes behind a paused elongating ribosome promotes initiation at upstream weak start sites. Ribosomal profiling reveals polyamine-dependent pausing of elongating ribosomes on a conserved Pro-Pro-Trp (PPW) motif in an inhibitory non-AUG-initiated upstream conserved coding region (uCC) of the antizyme inhibitor 1 (AZIN1) mRNA, encoding a regulator of cellular polyamine synthesis. Mutation of the PPW motif impairs initiation at the uCC's upstream near-cognate AUU start site and derepresses AZIN1 synthesis, whereas substitution of alternate elongation pause sequences restores uCC translation. Impairing ribosome loading reduces uCC translation and paradoxically derepresses AZIN1 synthesis. Finally, we identify the translation factor eIF5A as a sensor and effector for polyamine control of uCC translation. We propose that stalling of elongating ribosomes triggers queuing of scanning ribosomes and promotes initiation by positioning a ribosome near the start codon.
Assuntos
Proteínas de Transporte/biossíntese , Elongação Traducional da Cadeia Peptídica , Iniciação Traducional da Cadeia Peptídica , Poliaminas/metabolismo , RNA Mensageiro/metabolismo , Ribossomos/metabolismo , Motivos de Aminoácidos , Animais , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Códon de Iniciação , Sequência Conservada , Células HEK293 , Humanos , Camundongos , Fases de Leitura Aberta , Fatores de Iniciação de Peptídeos/genética , Fatores de Iniciação de Peptídeos/metabolismo , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribossomos/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fator de Iniciação de Tradução Eucariótico 5ARESUMO
Viruses rely on host cells for energy and synthesis machinery required for genome replication and particle assembly. Due to the dependence of viruses on host cells, viruses have evolved multiple mechanisms by which they can induce metabolic changes in the host cell to suit their specific requirements. The host immune response also involves metabolic changes to be able to react to viral insult. Polyamines are small ubiquitously expressed polycations, and their metabolism is critical for viral replication and an adequate host immune response. This is due to the variety of functions that polyamines have, ranging from condensing DNA to enhancing the translation of polyproline-containing proteins through the hypusination of eIF5A. Here, we review the diverse mechanisms by which viruses exploit polyamines, as well as the mechanisms by which immune cells utilize polyamines for their functions. Furthermore, we highlight potential avenues for further study of the host-virus interface.
Assuntos
Interações entre Hospedeiro e Microrganismos , Poliaminas , Viroses , Replicação Viral , Vírus , Humanos , Imunidade Adaptativa , Antineoplásicos/farmacologia , Antivirais/farmacologia , Eflornitina/farmacologia , Interações entre Hospedeiro e Microrganismos/imunologia , Poliaminas/antagonistas & inibidores , Poliaminas/metabolismo , Viroses/metabolismo , Viroses/virologia , Vírus/metabolismo , Processamento de Proteína Pós-Traducional , Lisina , Fator de Iniciação de Tradução Eucariótico 5ARESUMO
Polyamines promote cellular proliferation. Their levels are controlled by ornithine decarboxylase antizyme 1 (Az1, encoded by OAZ1), through the proteasome-mediated, ubiquitin-independent degradation of ornithine decarboxylase (ODC), the rate-limiting enzyme of polyamine biosynthesis. Az1-mediated degradation of other substrates such as cyclin D1 (CCND1), DNp73 (TP73) or Mps1 regulates cell growth and centrosome amplification, and the currently known six Az1 substrates are all linked with tumorigenesis. To understand whether Az1-mediated protein degradation might play a role in regulating other cellular processes associated with tumorigenesis, we employed quantitative proteomics to identify novel Az1 substrates. Here, we describe the identification of LIM domain and actin-binding protein 1 (LIMA1), also known as epithelial protein lost in neoplasm (EPLIN), as a new Az1 target. Interestingly, between the two EPLIN isoforms (α and ß), only EPLIN-ß is a substrate of Az1. The interaction between EPLIN-ß and Az1 appears to be indirect, and EPLIN-ß is degraded by Az1 in a ubiquitination-independent manner. Az1 absence leads to elevated EPLIN-ß levels, causing enhanced cellular migration. Consistently, higher LIMA1 levels correlate with poorer overall survival of colorectal cancer patients. Overall, this study identifies EPLIN-ß as a novel Az1 substrate regulating cellular migration.
Assuntos
Ornitina Descarboxilase , Ubiquitina , Humanos , Ornitina Descarboxilase/genética , Ornitina Descarboxilase/química , Ornitina Descarboxilase/metabolismo , Ubiquitina/metabolismo , Isoformas de Proteínas , Carcinogênese , Proteínas do CitoesqueletoRESUMO
Group 3 innate lymphoid cells (ILC3s) are RORγT+ lymphocytes that are predominately enriched in mucosal tissues and produce IL-22 and IL-17A. They are the innate counterparts of Th17 cells. While Th17 lymphocytes utilize unique metabolic pathways in their differentiation program, it is unknown whether ILC3s make similar metabolic adaptations. We employed single-cell RNA sequencing and metabolomic profiling of intestinal ILC subsets to identify an enrichment of polyamine biosynthesis in ILC3s, converging on the rate-limiting enzyme ornithine decarboxylase (ODC1). In vitro and in vivo studies demonstrated that exogenous supplementation with the polyamine putrescine or its biosynthetic substrate, ornithine, enhanced ILC3 production of IL-22. Conditional deletion of ODC1 in ILC3s impaired mouse antibacterial defense against Citrobacter rodentium infection, which was associated with a decrease in anti-microbial peptide production by the intestinal epithelium. Furthermore, in a model of anti-CD40 colitis, deficiency of ODC1 in ILC3s markedly reduced the production of IL-22 and severity of inflammatory colitis. We conclude that ILC3-intrinsic polyamine biosynthesis facilitates efficient defense against enteric pathogens as well as exacerbates autoimmune colitis, thus representing an attractive target to modulate ILC3 function in intestinal disease.
Assuntos
Colite , Infecções por Enterobacteriaceae , Camundongos , Animais , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Interleucina-17 , Ornitina Descarboxilase/genética , Imunidade Inata , Putrescina , Colite/genética , Infecções por Enterobacteriaceae/genética , Células Th17/metabolismo , Ornitina , Antibacterianos , Interleucina 22RESUMO
Polyamines are molecules with multiple amino groups that are essential for cellular function. The major polyamines are putrescine, spermidine, spermine, and cadaverine. Polyamines are important for posttranscriptional regulation, autophagy, programmed cell death, proliferation, redox homeostasis, and ion channel function. Their levels are tightly controlled. High levels of polyamines are associated with proliferative pathologies such as cancer, whereas low polyamine levels are observed in aging, and elevated polyamine turnover enhances oxidative stress. Polyamine metabolism is implicated in several pathophysiological processes in the nervous, immune, and cardiovascular systems. Currently, manipulating polyamine levels is under investigation as a potential preventive treatment for several pathologies, including aging, ischemia/reperfusion injury, pulmonary hypertension, and cancer. Although polyamines have been implicated in many intracellular mechanisms, our understanding of these processes remains incomplete and is a topic of ongoing investigation. Here, we discuss the regulation and cellular functions of polyamines, their role in physiology and pathology, and emphasize the current gaps in knowledge and potential future research directions.
Assuntos
Poliaminas , Humanos , Animais , Poliaminas/metabolismo , Estresse Oxidativo/fisiologia , Homeostase/fisiologia , Autofagia/fisiologiaRESUMO
Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a growing health concern due to its increasing prevalence worldwide. Metabolic homeostasis encompasses the stable internal conditions vital for efficient metabolism. This equilibrium extends to the intestinal microbiota, whose metabolic activities profoundly influence overall metabolic balance and organ health. The metabolites derived from the gut microbiota metabolism can be defined as microbiota-related co-metabolites. They serve as mediators between the gut microbiota and the host, influencing various physiological processes. The recent redefinition of the term MASLD has highlighted the metabolic dysfunction that characterize the disease. Metabolic dysfunction encompasses a spectrum of abnormalities, including impaired glucose regulation, dyslipidemia, mitochondrial dysfunction, inflammation, and accumulation of toxic byproducts. In addition, MASLD progression has been linked to dysregulation in the gut microbiota and associated co-metabolites. Short-chain fatty acids (SCFAs), hippurate, indole derivatives, branched-chain amino acids (BCAAs), and bile acids (BAs) are among the key co-metabolites implicated in MASLD progression. In this review, we will unravel the relationship between the microbiota-related metabolites which have been associated with MASLD and that could play an important role for developing effective therapeutic interventions for MASLD and related metabolic disorders.
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BACKGROUND: Food allergy (FA) in young children is often associated with eczema, frequently directed to egg/cow milk allergens and has a higher chance of resolution, while FA that persists in older children has less chance of resolution and is less clearly associated with atopy. METHODS: Children with FA (n = 62) and healthy controls (n = 28) were categorized into "younger" (≤5 years) and "older" (>5 years). Mass spectrometry-based untargeted metabolomic profiling as wells as cytokine profiling were performed on plasma samples in FA children in each age group. RESULTS: Younger FA children manifested unique alterations in bile acids, polyamine metabolites and chemokines associated with Th2 responses, while older FA children displayed pronounced changes in long chain fatty acids, acylcarnitines and proinflammatory cytokines. CONCLUSIONS: FA children of different ages manifest unique metabolic changes which may reflect at least in part pathogenic mechanisms and environmental influences operative at different time points in the disease course.
Assuntos
Eczema , Hipersensibilidade Alimentar , Hipersensibilidade Imediata , Criança , Feminino , Animais , Bovinos , Humanos , Pré-Escolar , Alérgenos , Fatores EtáriosRESUMO
BACKGROUND & AIMS: Postinfection irritable bowel syndrome (PI-IBS) is well-known epidemiologically; however, its physiological and molecular characteristics are not well studied. We aimed to determine the physiological phenotypes, colonic transcriptome, fecal microbiome, and metabolome in PI-IBS. METHODS: Fifty-one Rome III Campylobacter PI-IBS patients and 39 healthy volunteers (HV) were enrolled. Participants completed questionnaires, in vivo intestinal permeability, gastrointestinal transit, and rectal sensation. Fecal samples were collected for shotgun metagenomics, untargeted metabolomics, and sigmoid colonic biopsies for bulk RNAseq. Differential gene expression, differences in microbiota composition, and metabolite abundance were determined. Gene and metabolite clusters were identified via weighted gene correlation network analysis and correlations with clinical and physiological parameters determined. RESULTS: PI-IBS (59% female; 46 ± 2 years) and HV (64% female; 42 ± 2 years) demographics were comparable. Mean IBS-symptom severity score was 227; 94% were nonconstipation. Two- to 24-hour lactulose excretion was increased in PI-IBS, suggesting increased colonic permeability (4.4 ± 0.5 mg vs 2.6 ± 0.3 mg; P = .01). Colonic transit and sensory thresholds were similar between the 2 groups. Overall, expression of 2036 mucosal genes and 223 fecal metabolites were different, with changes more prominent in females. Fecal N-acetylputrescine was increased in PI-IBS and associated with colonic permeability, worse diarrhea, and negatively correlated with abundance of Collinsella aerofaciens. Histamine and N-acetylhistamine positively associated with 2- to 24-hour lactulose excretion. Eight weighted gene coexpression modules significantly correlated with phenotypes (sex, stool frequency, colonic permeability, transit). CONCLUSIONS: Campylobacter PI-IBS patients demonstrate higher colonic permeability, which associated with changes in polyamine and histamine metabolites. Female patients demonstrated greater molecular changes.
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Polyamines (PAs) are pleiotropic bioorganic molecules. Cellular PA contents are determined by a balance between PA synthesis and degradation. PAs have been extensively demonstrated to play vital roles in the modulation of plant developmental processes and adaptation to various environmental stresses. In this review, the latest advances on the diverse roles of PAs in a range of developmental processes, such as morphogenesis, organogenesis, growth and development, and fruit ripening, are summarized and discussed. Besides, the crosstalk between PAs and phytohormones or other signalling molecules, including H2O2 and NO, involved in these processes is dwelled on. In addition, the attempts made to improve the yield and quality of grain and vegetable crops through altering the PA catabolism are enumerated. Finally, several other vital questions that remain unanswered are proposed and discussed. These include the mechanisms underlying the cooperative regulation of developmental processes by PAs and their interplaying partners like phytohormones, H2O2 and NO; PA transport for maintaining homeostasis; and utilization of PA anabolism/catabolism for generating high-yield and good-quality crops. This review aims to gain new insights into the pleiotropic role of PAs in the modulation of plant growth and development, which provides an alternative approach for manipulating and engineering valuable crop varieties that can be used in the future.
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Bee venom serves as an essential defensive weapon for bees and also finds application as a medicinal drug. MicroRNAs (miRNAs) serve as critical regulators and have been demonstrated to perform a variety of biological functions. However, the presence of miRNAs in bee venom needs to be confirmed. Therefore, we conducted small RNA sequencing and identified 158 known miRNAs, 15 conserved miRNAs and 4 novel miRNAs. It is noteworthy that ame-miR-1-3p, the most abundant among them, accounted for over a quarter of all miRNA reads. To validate the function of ame-miR-1-3p, we screened 28 candidate target genes using transcriptome sequencing and three target gene prediction software (miRanda, PITA and TargetScan) for ame-miR-1-3p. Subsequently, we employed real-time quantitative reverse transcription PCR (qRT-PCR), Western blot and other technologies to confirm that ame-miR-1-3p inhibits the relative expression of antizyme inhibitor 1 (AZIN1) by targeting the 3' untranslated region (UTR) of AZIN1. This, in turn, caused ODC antizyme 1 (OAZ1) to bind to ornithine decarboxylase 1 (ODC1) and mark ODC1 for proteolytic destruction. The reduction in functional ODC1 ultimately resulted in a decrease in polyamine biosynthesis. Furthermore, we determined that ame-miR-1-3p accelerates cell death through the AZIN1/OAZ1-ODC1-polyamines pathway. Our studies demonstrate that ame-miR-1-3p diminishes cell viability and it may collaborate with sPLA2 to enhance the defence capabilities of honeybees (Apis mellifera L.). Collectively, these data further elucidate the defence mechanism of bee venom and expand the potential applications of bee venom in medical treatment.
Assuntos
Venenos de Abelha , Proteínas de Insetos , MicroRNAs , Animais , Abelhas/genética , Abelhas/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Venenos de Abelha/farmacologia , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Sobrevivência Celular , Poliaminas/metabolismo , Ornitina Descarboxilase/metabolismo , Ornitina Descarboxilase/genéticaRESUMO
Periodontitis is an inflammatory condition of supporting structures of teeth leading to attachment and bone loss. Cigarette smoking is the single most important and modifiable risk factor with 5 to 20-fold susceptibility for periodontal diseases. Reverse smoking is a peculiar habit of smoking where the lit end is kept inside the mouth, which is predominant in the northern coastal districts of Andhra Pradesh. Polyamines are biologically active amines involved in tissue regeneration and modulation of inflammation. The study aimed to evaluate polyamines and check their utility as a marker in detection of periodontitis among different groups. Total polyamine levels showed significant increase in reverse smokers with periodontitis when compared to the other groups. Qualitative analysis by thin layer chromatography showed three polyamine bands with varying intensity among the different groups. Mass spectrometric and NMR analyses of the three bands identified them as N1, N8-diacetyl spermidine, N-acetyl cadaverine and lysine. Most significantly elevated levels of lysine was observed in the smoker and reverse smoker periodontitis groups when compared to healthy and non-smoker periodontitis groups. The significantly elevated levels of N-acetyl cadaverine could be responsible for the more destruction of periodontium in the reverse smoker group. Antioxidant potential decreased significantly in different smoker periodontitis groups. The present study suggests that the quantitative analysis of salivary polyamines, lysine and N-acetyl cadaverine can aid as an easy noninvasive diagnostic method for assessing the periodontal status, especially in smokers.
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Biomarcadores , Cadaverina , Lisina , Periodontite , Humanos , Periodontite/metabolismo , Periodontite/diagnóstico , Cadaverina/metabolismo , Cadaverina/análise , Biomarcadores/metabolismo , Biomarcadores/análise , Lisina/análogos & derivados , Lisina/análise , Lisina/metabolismo , Adulto , Masculino , Fumantes , Feminino , Pessoa de Meia-Idade , Fumar , Saliva/química , Saliva/metabolismoRESUMO
Exogenous polyamines, including putrescine (PUT), spermidine (SPD), and spermine (SPM), and the irreversible inhibitor of the rate-limiting enzyme ornithine decarboxylase (ODC) of polyamine biosynthesis, α-difluoromethylornithine (DFMO), are implicated as stimulants for bone formation. We demonstrate in this study the osteogenic potential of exogenous polyamines and DFMO in human osteoblasts (hOBs), murine monocyte cell line RAW 264.7, and an ovariectomized rat model. The effect of polyamines and DFMO on hOBs and RAW 264.7 cells was studied by analyzing gene expression, alkaline phosphatase (ALP) activity, tartrate-resistant acid phosphatase (TRAP) activity, and matrix mineralization. Ovariectomized rats were treated with polyamines and DFMO and analyzed by micro computed tomography (micro CT). The mRNA level of the early onset genes of osteogenic differentiation, Runt-related transcription factor 2 (Runx2) and ALP, was significantly elevated in hOBs under osteogenic conditions, while both ALP activity and matrix mineralization were enhanced by exogenous polyamines and DFMO. Under osteoclastogenic conditions, the gene expression of both receptor activator of nuclear factor-κB (RANK) and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) was reduced, and TRAP activity was suppressed by exogenous polyamines and DFMO in RAW 264.7 cells. In an osteoporotic animal model of ovariectomized rats, SPM and DFMO were found to improve bone volume in rat femurs, while trabecular thickness was increased in all treatment groups. Results from this study provide in vitro and in vivo evidence indicating that polyamines and DFMO act as stimulants for bone formation, and their osteogenic effect may be associated with the suppression of osteoclastogenesis.
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Diferenciação Celular , Eflornitina , Osteoblastos , Osteoclastos , Osteogênese , Poliaminas , Animais , Camundongos , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Ratos , Humanos , Diferenciação Celular/efeitos dos fármacos , Eflornitina/farmacologia , Feminino , Poliaminas/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Células RAW 264.7 , Ovariectomia , Ratos Sprague-Dawley , Espermidina/farmacologiaRESUMO
Epidemiological studies on the potential health effects of dietary polyamines are scarce. The present study aimed to estimate habitual intake of polyamines (putrescine, spermidine and spermine) and examine whether spermidine intake is inversely associated with all-cause and cause-specific mortality in a population-based cohort study in Japan. The study included 13 355 men and 15 724 women aged 35 years and older. Diet was assessed via a validated FFQ at the baseline in 1992. The intake of polyamines was estimated mainly using databases of polyamine content in foods consumed among Japanese population. Sex-specific hazard ratios (HR) and 95 % CI for all-cause and cause-specific mortality were estimated according to polyamine quartiles. During 16 years of follow-up, 2901 deaths in men and 2438 in women occurred. The intake of any polyamine was not significantly associated with all-cause or cause-specific mortality after controlling for covariates in men and women. There was a suggestive positive association between spermidine intake and cancer mortality in women: HR for the highest v. lowest quartile were 1·38 (95 % CI (0·99, 1·93); Ptrend = 0·02). Our results did not provide support for the notion that dietary spermidine has beneficial effects on mortality. Further studies on dietary polyamines and longevity, as well as the morbidity of specific diseases, including cancer, are needed across populations with different dietary habits.