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MicrobiologyOpen Apr 2024Arginine-ornithine metabolism plays a crucial role in bacterial homeostasis, as evidenced by numerous studies. However, the utilization of arginine and the downstream...
Arginine-ornithine metabolism plays a crucial role in bacterial homeostasis, as evidenced by numerous studies. However, the utilization of arginine and the downstream products of its metabolism remain undefined in various gut bacteria. To bridge this knowledge gap, we employed genomic screening to pinpoint relevant metabolic targets. We also devised a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics method to measure the levels of arginine, its upstream precursors, and downstream products in cell-free conditioned media from enteric pathobionts, including Escherichia coli, Klebsiella aerogenes, K. pneumoniae, Pseudomonas fluorescens, Acinetobacter baumannii, Streptococcus agalactiae, Staphylococcus epidermidis, S. aureus, and Enterococcus faecalis. Our findings revealed that all selected bacterial strains consumed glutamine, glutamate, and arginine, and produced citrulline, ornithine, and GABA in our chemically defined medium. Additionally, E. coli, K. pneumoniae, K. aerogenes, and P. fluorescens were found to convert arginine to agmatine and produce putrescine. Interestingly, arginine supplementation promoted biofilm formation in K. pneumoniae, while ornithine supplementation enhanced biofilm formation in S. epidermidis. These findings offer a comprehensive insight into arginine-ornithine metabolism in enteric pathobionts.
Topics: Ornithine; Putrescine; Arginine; Escherichia coli; Chromatography, Liquid; Staphylococcus aureus; Tandem Mass Spectrometry; Bacteria; Klebsiella pneumoniae
PubMed: 38560776
DOI: 10.1002/mbo3.1408 -
International Journal of Molecular... Dec 2023Cardiogenic shock (CS) portends a dismal prognosis if hypoperfusion triggers uncontrolled inflammatory and metabolic derangements. We sought to investigate metabolomic...
Cardiogenic shock (CS) portends a dismal prognosis if hypoperfusion triggers uncontrolled inflammatory and metabolic derangements. We sought to investigate metabolomic profiles and temporal changes in IL6, Ang-2, and markers of glycocalyx perturbation from admission to discharge in eighteen patients with heart failure complicated by CS (HF-CS). Biological samples were collected from 18 consecutive HF-CS patients at admission (T0), 48 h after admission (T1), and at discharge (T2). ELISA analytical techniques and targeted metabolomics were performed Seven patients (44%) died at in-hospital follow-up. Among the survivors, IL-6 and kynurenine were significantly reduced at discharge compared to baseline. Conversely, the amino acids arginine, threonine, glycine, lysine, and asparagine; the biogenic amine putrescine; multiple sphingolipids; and glycerophospholipids were significantly increased. Patients with HF-CS have a metabolomic fingerprint that might allow for tailored treatment strategies for the patients' recovery or stabilization.
Topics: Humans; Shock, Cardiogenic; Heart Failure; Metabolomics; Amino Acids; Kynurenine; Hospital Mortality
PubMed: 38139435
DOI: 10.3390/ijms242417607 -
The Journal of Biological Chemistry Aug 2023Polyamines are positively charged alkylamines ubiquitous among eukaryotes, prokaryotes, and archaea. Humans obtain polyamines through dietary intake, metabolic...
Polyamines are positively charged alkylamines ubiquitous among eukaryotes, prokaryotes, and archaea. Humans obtain polyamines through dietary intake, metabolic production, or uptake of polyamines made by gut microbes. The polyamine biosynthetic pathway used by most gut microbes differs from that used by human cells. This alternative pathway employs carboxyspermidine dehydrogenase (CASDH), an enzyme with limited characterization. Here, we solved a 1.94 Å X-ray crystal structure of Bacteroides fragilis CASDH by molecular replacement. BfCASDH is composed of three domains with a fold similar to saccharopine dehydrogenase but with a distinct active site arrangement. Using steady-state methods, we determined k and k/K for BfCASDH and Clostridium leptum CASDH using putrescine, diaminopropane, aspartate semi-aldehyde, NADH, and NADPH as substrates. These data revealed evidence of cooperativity in BfCASDH. Putrescine is the likely polyamine substrate and NADPH is the coenzyme used to complete the reaction, forming carboxyspermidine as a product. These data provide the first kinetic characterization of CASDH-a key enzyme in the production of microbial polyamines.
Topics: Humans; NADP; Oxidoreductases; Polyamines; Putrescine; Spermidine; Bacteroides fragilis
PubMed: 37437886
DOI: 10.1016/j.jbc.2023.105033 -
BMC Plant Biology Nov 2023Two spotted spider mite, Tetranychus urticae (Acari: Tetranychidae) is one of the most important plant pests in the world. Due to increased resistance of mites to...
BACKGROUND
Two spotted spider mite, Tetranychus urticae (Acari: Tetranychidae) is one of the most important plant pests in the world. Due to increased resistance of mites to acaricides, it is necessary to use other methods such as inducing resistance in plants by natural compounds for pests' management. Polyamins such as spermine are effective in increasing plant resistance to biotic and abiotic stressors. In this research, the effect of spermine treatments in cucumber plants on life table parameters of T. urticae was investigated. Also, top-down effect of spermine and T. urticae on cucumber biochemical parameters was measured. In the experiments, 1, 2 and 3 mM spermine concentrations were used.
RESULTS
Amongst the spermine treatments, those mites that fed on cucumbers which received 1 mM spermine showed the shortest protonymphal period and higher ovipositon period, fecundity, gross and net reproductive rates and life expectancy compare to control. Treatment with 2 mM spermine lead to the longest teleochrysalis period and shortest range of age-stage-specific fecundity period. In addition, 2 mM spermine lowered intrinsic and finite rate of population increase in T. urticae. The longest larval period of T. urticae was observed in 3 mM spermine. Feeding of T. urticae from cucumber plants increased hydrogen peroxide (HO), malondialdehyde (MDA) content, electrolyte leakage (EL) level and ascorbate peroxidase (APX) activity but inhibited catalase (CAT) activity in this plant. Infested cucumber plants treated with 2 mM spermine showed lower HO and MDA content and highest activity of APX and CAT on day 1 and 3 compare to the others. The 3 mM spermine increased HO content in infested plants during the whole experiment as well as non-infested plants in day 5 and 9 only. This treatment induced the highest MDA content and lowest catalase activity on day1, 3 and 5 of experiment in infested plants.
CONCLUSION
This study showed that 2 mM spermine was the only effective concentration that reduce cucumber sensitivity to T. urticae. The trend of changes in biochemical parameters, especially HO, in 3 mM spermine was abnormal, and this concentration could be considered toxic.
Topics: Animals; Cucumis sativus; Tetranychidae; Spermine; Hydrogen Peroxide; Catalase
PubMed: 37978429
DOI: 10.1186/s12870-023-04573-5 -
Molecular Brain Mar 2024Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3, is a fatal neurodegenerative disease that causes loss of balance and motor co-ordination,...
Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3, is a fatal neurodegenerative disease that causes loss of balance and motor co-ordination, eventually leading to paralysis. It is caused by the autosomal dominant inheritance of a long CAG trinucleotide repeat sequence within the ATXN3 gene, encoding for an expanded polyglutamine (polyQ) repeat sequence within the ataxin-3 protein. Ataxin-3 containing an expanded polyQ repeat is known to be highly prone to intraneuronal aggregation, and previous studies have demonstrated that protein quality control pathways, such as autophagy, are impaired in MJD patients and animal models of the disease. In this study, we tested the therapeutic potential of spermidine on zebrafish and rodent models of MJD to determine its capacity to induce autophagy and improve functional output. Spermidine treatment of transgenic MJD zebrafish induced autophagy and resulted in increased distances swum by the MJD zebrafish. Interestingly, treatment of the CMVMJD135 mouse model of MJD with spermidine added to drinking water did not produce any improvement in motor behaviour assays, neurological testing or neuropathology. In fact, wild type mice treated with spermidine were found to have decreased rotarod performance when compared to control animals. Immunoblot analysis of protein lysates extracted from mouse cerebellar tissue found little differences between the groups, except for an increased level of phospho-ULK1 in spermidine treated animals, suggesting that autophagy was indeed induced. As we detected decreased motor performance in wild type mice following treatment with spermidine, we conducted follow up studies into the effects of spermidine treatment in zebrafish. Interestingly, we found that in addition to inducing autophagy, spermidine treatment also induced apoptosis, particularly in wild type zebrafish. These findings suggest that spermidine treatment may not be therapeutically beneficial for the treatment of MJD, and in fact warrants caution due to the potential negative side effects caused by induction of apoptosis.
Topics: Humans; Animals; Mice; Neurodegenerative Diseases; Spermidine; Zebrafish; Apoptosis; Autophagy; Disease Models, Animal; Machado-Joseph Disease
PubMed: 38443995
DOI: 10.1186/s13041-024-01085-7 -
ELife Mar 2024Hepatic ischemia/reperfusion injury (HIRI) is a common and inevitable factor leading to poor prognosis in various liver diseases, making the outcomes of current...
Hepatic ischemia/reperfusion injury (HIRI) is a common and inevitable factor leading to poor prognosis in various liver diseases, making the outcomes of current treatments in clinic unsatisfactory. Metformin has been demonstrated to be beneficial to alleviate HIRI in recent studies, however, the underpinning mechanism remains unclear. In this study, we found metformin mitigates HIRI-induced ferroptosis through reshaped gut microbiota in mice, which was confirmed by the results of fecal microbiota transplantation treatment but showed the elimination of the beneficial effects when gut bacteria were depleted using antibiotics. Detailedly, through 16S rRNA and metagenomic sequencing, we identified that the metformin-reshaped microbiota was characterized by the increase of gamma-aminobutyric acid (GABA) producing bacteria. This increase was further confirmed by the elevation of GABA synthesis key enzymes, glutamic acid decarboxylase and putrescine aminotransferase, in gut microbes of metformin-treated mice and healthy volunteers. Furthermore, the benefit of GABA against HIRI-induced ferroptosis was demonstrated in GABA-treated mice. Collectively, our data indicate that metformin can mitigate HIRI-induced ferroptosis by reshaped gut microbiota, with GABA identified as a key metabolite.
Topics: Humans; Mice; Animals; Metformin; Gastrointestinal Microbiome; RNA, Ribosomal, 16S; Ferroptosis; Reperfusion Injury; Ischemia; gamma-Aminobutyric Acid
PubMed: 38488837
DOI: 10.7554/eLife.89045 -
Cell Death & Disease May 2024Precise polyamine metabolism regulation is vital for cells and organisms. Mutations in spermine synthase (SMS) cause Snyder-Robinson intellectual disability syndrome...
Precise polyamine metabolism regulation is vital for cells and organisms. Mutations in spermine synthase (SMS) cause Snyder-Robinson intellectual disability syndrome (SRS), characterized by significant spermidine accumulation and autophagy blockage in the nervous system. Emerging evidence connects polyamine metabolism with other autophagy-related diseases, such as Tauopathy, however, the functional intersection between polyamine metabolism and autophagy in the context of these diseases remains unclear. Here, we altered SMS expression level to investigate the regulation of autophagy by modulated polyamine metabolism in Tauopathy in Drosophila and human cellular models. Interestingly, while complete loss of Drosophila spermine synthase (dSms) impairs lysosomal function and blocks autophagic flux recapitulating SRS disease phenotype, partial loss of dSms enhanced autophagic flux, reduced Tau protein accumulation, and led to extended lifespan and improved climbing performance in Tauopathy flies. Measurement of polyamine levels detected a mild elevation of spermidine in flies with partial loss of dSms. Similarly, in human neuronal or glial cells, partial loss of SMS by siRNA-mediated knockdown upregulated autophagic flux and reduced Tau protein accumulation. Importantly, proteomics analysis of postmortem brain tissue from Alzheimer's disease (AD) patients showed a significant albeit modest elevation of SMS level. Taken together, our study uncovers a functional correlation between polyamine metabolism and autophagy in AD: SMS reduction upregulates autophagy, suppresses Tau accumulation, and ameliorates neurodegeneration and cell death. These findings provide a new potential therapeutic target for AD.
Topics: Autophagy; Animals; tau Proteins; Humans; Spermine Synthase; Drosophila melanogaster; Drosophila Proteins; Tauopathies; Neurons; Alzheimer Disease; Spermidine; Disease Models, Animal; Lysosomes; Drosophila; Mental Retardation, X-Linked
PubMed: 38740758
DOI: 10.1038/s41419-024-06720-8 -
Breast Cancer Research : BCR Apr 2024Basal-like breast cancer (BLBC) is the most aggressive subtype of breast cancer due to its aggressive characteristics and lack of effective therapeutics. However, the...
BACKGROUND
Basal-like breast cancer (BLBC) is the most aggressive subtype of breast cancer due to its aggressive characteristics and lack of effective therapeutics. However, the mechanism underlying its aggressiveness remains largely unclear. S-adenosylmethionine decarboxylase proenzyme (AMD1) overexpression occurs specifically in BLBC. Here, we explored the potential molecular mechanisms and functions of AMD1 promoting the aggressiveness of BLBC.
METHODS
The potential effects of AMD1 on breast cancer cells were tested by western blotting, colony formation, cell proliferation assay, migration and invasion assay. The spermidine level was determined by high performance liquid chromatography. The methylation status of CpG sites within the AMD1 promoter was evaluated by bisulfite sequencing PCR. We elucidated the relationship between AMD1 and Sox10 by ChIP assays and quantitative real-time PCR. The effect of AMD1 expression on breast cancer cells was evaluated by in vitro and in vivo tumorigenesis model.
RESULTS
In this study, we showed that AMD1 expression was remarkably elevated in BLBC. AMD1 copy number amplification, hypomethylation of AMD1 promoter and transcription activity of Sox10 contributed to the overexpression of AMD1 in BLBC. AMD1 overexpression enhanced spermidine production, which enhanced eIF5A hypusination, activating translation of TCF4 with multiple conserved Pro-Pro motifs. Our studies showed that AMD1-mediated metabolic system of polyamine in BLBC cells promoted tumor cell proliferation and tumor growth. Clinically, elevated expression of AMD1 was correlated with high grade, metastasis and poor survival, indicating poor prognosis of breast cancer patients.
CONCLUSION
Our work reveals the critical association of AMD1-mediated spermidine-eIF5A hypusination-TCF4 axis with BLBC aggressiveness, indicating potential prognostic indicators and therapeutic targets for BLBC.
Topics: Humans; Female; Breast Neoplasms; Eukaryotic Translation Initiation Factor 5A; Peptide Initiation Factors; Mice; Animals; Gene Expression Regulation, Neoplastic; Cell Proliferation; Spermidine; RNA-Binding Proteins; Transcription Factor 4; Cell Line, Tumor; Promoter Regions, Genetic; Adenosylmethionine Decarboxylase; Cell Movement; DNA Methylation; Prognosis; SOXE Transcription Factors; Lysine
PubMed: 38654332
DOI: 10.1186/s13058-024-01825-6 -
The British Journal of Nutrition Nov 2023Only 6 to 8 % of the UK adults meet the daily recommendation for dietary fibre. Fava bean processing lead to vast amounts of high-fibre by-products such as hulls. Bean... (Randomized Controlled Trial)
Randomized Controlled Trial
Habitual consumption of high-fibre bread fortified with bean hulls increased plasma indole-3-propionic concentration and decreased putrescine and deoxycholic acid faecal concentrations in healthy volunteers.
Only 6 to 8 % of the UK adults meet the daily recommendation for dietary fibre. Fava bean processing lead to vast amounts of high-fibre by-products such as hulls. Bean hull fortified bread was formulated to increase and diversify dietary fibre while reducing waste. This study assessed the bean hull: suitability as a source of dietary fibre; the systemic and microbial metabolism of its components and postprandial events following bean hull bread rolls. Nine healthy participants (53·9 ± 16·7 years) were recruited for a randomised controlled crossover study attending two 3 days intervention sessions, involving the consumption of two bread rolls per day (control or bean hull rolls). Blood and faecal samples were collected before and after each session and analysed for systemic and microbial metabolites of bread roll components using targeted LC-MS/MS and GC analysis. Satiety, gut hormones, glucose, insulin and gastric emptying biomarkers were also measured. Two bean hull rolls provided over 85 % of the daily recommendation for dietary fibre; but despite being a rich source of plant metabolites ( = 0·04 . control bread), these had poor systemic bioavailability. Consumption of bean hull rolls for 3 days significantly increased plasma concentration of indole-3-propionic acid ( = 0·009) and decreased faecal concentration of putrescine ( = 0·035) and deoxycholic acid ( = 0·046). However, it had no effect on postprandial plasma gut hormones, bacterial composition and faecal short chain fatty acids amount. Therefore, bean hulls require further processing to improve their bioactives systemic availability and fibre fermentation.
Topics: Adult; Humans; Healthy Volunteers; Putrescine; Bread; Chromatography, Liquid; Cross-Over Studies; Tandem Mass Spectrometry; Gastrointestinal Hormones; Dietary Fiber; Fabaceae; Deoxycholic Acid; Blood Glucose
PubMed: 36847278
DOI: 10.1017/S0007114523000491 -
Biomedicine & Pharmacotherapy =... Feb 2024Adiponectin has been shown to mediate cardioprotective effects and levels are typically reduced in patients with cardiometabolic disease. Hence, there has been intense...
AIMS
Adiponectin has been shown to mediate cardioprotective effects and levels are typically reduced in patients with cardiometabolic disease. Hence, there has been intense interest in developing adiponectin-based therapeutics. The aim of this translational research study was to examine the functional significance of targeting adiponectin signaling with the adiponectin receptor agonist ALY688 in a mouse model of heart failure with reduced ejection fraction (HFrEF), and the mechanisms of cardiac remodeling leading to cardioprotection.
METHODS AND RESULTS
Wild-type mice were subjected to transverse aortic constriction (TAC) to induce left ventricular pressure overload (PO), or sham surgery, with or without daily subcutaneous ALY688-SR administration. Temporal analysis of cardiac function was conducted via weekly echocardiography for 5 weeks and we observed that ALY688 attenuated the PO-induced dysfunction. ALY688 also reduced cardiac hypertrophic remodeling, assessed via LV mass, heart weight to body weight ratio, cardiomyocyte cross sectional area, ANP and BNP levels. ALY688 also attenuated PO-induced changes in myosin light and heavy chain expression. Collagen content and myofibroblast profile indicated that fibrosis was attenuated by ALY688 with TIMP1 and scleraxis/periostin identified as potential mechanistic contributors. ALY688 reduced PO-induced elevation in circulating cytokines including IL-5, IL-13 and IL-17, and the chemoattractants MCP-1, MIP-1β, MIP-1alpha and MIP-3α. Assessment of myocardial transcript levels indicated that ALY688 suppressed PO-induced elevations in IL-6, TLR-4 and IL-1β, collectively indicating anti-inflammatory effects. Targeted metabolomic profiling indicated that ALY688 increased fatty acid mobilization and oxidation, increased betaine and putrescine plus decreased sphingomyelin and lysophospholipids, a profile indicative of improved insulin sensitivity.
CONCLUSION
These results indicate that the adiponectin mimetic peptide ALY688 reduced PO-induced fibrosis, hypertrophy, inflammation and metabolic dysfunction and represents a promising therapeutic approach for treating HFrEF in a clinical setting.
Topics: Humans; Mice; Animals; Heart Failure; Adiponectin; Receptors, Adiponectin; Stroke Volume; Myocytes, Cardiac; Fibrosis; Ventricular Remodeling; Mice, Inbred C57BL
PubMed: 38181714
DOI: 10.1016/j.biopha.2023.116119