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Research Square Apr 2024Latent tuberculosis infection (LTBI) is common in people living with HIV (PLHIV) in high TB burden settings. Active TB is associated with specific stool taxa; however,...
BACKGROUND
Latent tuberculosis infection (LTBI) is common in people living with HIV (PLHIV) in high TB burden settings. Active TB is associated with specific stool taxa; however, little is known about the stool microbiota and LTBI, including in PLHIV.
METHOD
Within a parent study that recruited adult females with HIV from Cape Town, South Africa into predefined age categories (18-25, 35-60 years), we characterised the stool microbiota of those with [interferon-γ release assay (IGRA)- and tuberculin skin test (TST)-positive] or without (IGRA- and TST- negative) LTBI (n=25 per group). 16S rRNA DNA sequences were analysed using QIIME2, Dirichlet Multinomial Mixtures, DESeq2 and PICRUSt2.
RESULTS
No α- or β-diversity differences occurred by LTBI status; however, LTBI-positives were depleted. Inferred metagenome data showed LTBI-negative-enriched pathways included several involved in methylglyoxal degradation, L-arginine, putrescine, 4-aminobutanoate degradation and L-arginine and ornithine degradation. Stool from LTBI-positives demonstrated differential taxa abundance based on a quantitative response to antigen stimulation (depletion associated with higher IGRA or TST responses, respectively). In LTBI-positives, older people had different β-diversities than younger people whereas, in LTBI-negatives, no differences occurred across age groups.
CONCLUSION
Amongst female PLHIV, those with LTBI had, vs. those without LTBI, Gemmiger-enriched, which are producers of short chain fatty acids. Taxonomic differences amongst people with LTBI occurred according to quantitative response to antigen stimulation and age. These data enhance our understanding of the microbiome's potential role in LTBI.
PubMed: 38645218
DOI: 10.21203/rs.3.rs-4182285/v1 -
DAB-APT: a Fluorescence-Based Assay for Determining Aminopropyl Transferase Activity and Inhibition.BioRxiv : the Preprint Server For... Apr 2024Polyamines are polycationic molecules that are crucial in a wide array of cellular functions. Their biosynthesis is mediated by aminopropyl transferases (APTs),...
Polyamines are polycationic molecules that are crucial in a wide array of cellular functions. Their biosynthesis is mediated by aminopropyl transferases (APTs), promising targets in antimicrobial, antineoplastic and antineurodegenerative therapies. A major limitation, however, is the lack of high-throughput assays to measure their activity. We developed the first fluorescence-based assay, DAB-APT, for measurement of APT activity using 1,2-diacetyl benzene, which forms fluorescent conjugates with putrescine, spermidine and spermine with fluorescence intensity increasing with increasing carbon chain length. The assay has been validated using APT enzymes from and and is suitable for high-throughput screening of large chemical libraries. Given the importance of APTs in infectious diseases, cancer and neurobiology, our DAB-APT assay has broad applications, holding promise for advancing research and drug discovery efforts.
PubMed: 38645036
DOI: 10.1101/2024.04.09.588734 -
Food Science & Nutrition Apr 2024This study aimed at investigating the quality attributes of Turkish fermented sausage (sucuk) incorporated with bay leaf extract obtained as a natural antioxidant and a...
This study aimed at investigating the quality attributes of Turkish fermented sausage (sucuk) incorporated with bay leaf extract obtained as a natural antioxidant and a source of phytochemicals. Five different bay leaf extracts were obtained with distilled water and 60%, 70%, 80%, and 90% ethanol. The total phenolic contents and antioxidant activity values indicated that ultrasound-assisted 70% ethanol extract was the most suitable extract. Furthermore, five groups of sucuks were manufactured with the addition of bay leaf extract (1, 5, and 10 mL/kg), ascorbic acid (500 mg/kg), and control. The extracts were produced similar pH values when compared to control and ascorbic acid samples. The treatments had no significant effect on moisture contents of sucuks. Bay leaf extracts produced comparable color, texture profile analysis, and TBARS values to control and ascorbic acid samples. Biogenic amine contents (mg/kg dry weight) of sucuks including tryptamine (6.43-30.66), 2-phenylethylamine (2.24-32.04), putrescine (2.19-7.98), cadaverine (3.28-12.21), histamine (7.01-11.38), tyramine (3.27-71.07), spermidine (4.44-8.01), and spermine (53.96-68.25) were mostly within the lower ranges typically associated with sucuk. However, the lowest cadaverine values observed at the end of storage in the bay leaf extract added samples indicated that bay leaf extract might be effective in decreasing cadaverine values during storage. The addition of bay leaf extract caused similar sensory attributes to the control and ascorbic acid samples. This study revealed that Turkish fermented sucuks could be effectively incorporated with bay leaf extracts without a negative effect on the quality attributes or consumer acceptability.
PubMed: 38628223
DOI: 10.1002/fsn3.3929 -
MSystems May 2024is a ubiquitous Gram-negative opportunistic pathogen with remarkable phylogenetic and phenotypic variabilities. In this work, we applied classical molecular networking...
is a ubiquitous Gram-negative opportunistic pathogen with remarkable phylogenetic and phenotypic variabilities. In this work, we applied classical molecular networking analysis to secondary metabolite profiling data from seven strains, including five clinical isolates from the lung secretions of people with cystic fibrosis (CF). We provide three vignettes illustrating how secondary metabolite profiling aids in the identification of rare genomics traits in . First, we describe the identification of a previously unreported class of acyl putrescines produced by isolate mFLRO1. Secondary analysis of publicly available metabolomics data revealed that acyl putrescines are produced by <5% of strains. Second, we show that isolate SH3A does not produce di-rhamnolipids. Whole-genome sequencing and comparative genomics revealed that SH3A cannot produce di-rhamnolipids because its genome belongs to clade 5 of the phylogenetic tree. Previous phylogenetic analysis of thousands of strains concluded that <1% of publicly available genome sequences contribute to this clade. Last, we show that isolate SH1B does not produce the phenazine pyocyanin or rhamnolipids because it has a one-base insertion frameshift mutation (678insC) in the gene , which disrupts -driven quorum sensing. Secondary analysis of the tens of thousands of publicly available genomes in the National Center for Biotechnology Information (NCBI) and the Genome Database revealed that this mutation was present in only four genomes. Taken together, this study highlights that secondary metabolite profiling combined with genomic analysis can identify rare genetic traits of isolates.IMPORTANCESecondary metabolite profiling of five isolates from cystic fibrosis sputum captured three traits present in <1%-5% of publicly available data, pointing to how our current library of strains may not represent the diversity within this species or the genetic variance that occurs in the CF lung.
Topics: Pseudomonas aeruginosa; Humans; Genome, Bacterial; Cystic Fibrosis; Phylogeny; Secondary Metabolism; Glycolipids; Genomics; Pseudomonas Infections; Metabolomics; Metabolome
PubMed: 38619244
DOI: 10.1128/msystems.00339-24 -
International Journal of Nanomedicine 2024Natural nanoparticles have been found to exist in traditional Chinese medicine (TCM) decoctions. However, whether natural nanoparticles can influence the oral...
BACKGROUND
Natural nanoparticles have been found to exist in traditional Chinese medicine (TCM) decoctions. However, whether natural nanoparticles can influence the oral bioavailability of active compounds has not been elucidated. Using Xie-Bai-San decoction (XBSD) as an example, the purpose of this study was to isolate, characterize and elucidate the mechanism of the nanoparticles (N-XBSD) in XBSD, and further to explore whether the bioavailability of the main active compounds could be enhanced by N-XBSD.
METHODS
N-XBSD were isolated from XBSD, and investigated its characterization and study of its formation mechanism, and evaluation of its ability to enhance bioavailability of active compounds.
RESULTS
The N-XBSD was successfully isolated with the average particle size of 104.53 nm, PDI of 0.27 and zeta potential of -5.14 mV. Meanwhile, all the eight active compounds were most presented in N-XBSD. Kukoamine B could self-assemble with mulberroside A or liquiritin to form nanoparticles, respectively. And the FT-IR and HRMS results indicated the possible binding of the ammonium group of kukoamine B with the phenolic hydroxyl group of mulberroside A or liquiritin, respectively. The established UPLC-MS/MS method was accurate and reliable and met the quantitative requirements. The pharmacokinetic behaviors of the N-XBSD and decoction were similar in rats. Most notably, compared to that of free drugs, the , AUC, AUC, and MRT values of index compounds were the higher in N-XBSD, with a slower plasma clearance rate in rats.
CONCLUSION
The major active compounds of XBSD were mainly distributed in N-XBSD, and N-XBSD was formed through self-assembly among active compounds. N-XBSD could obviously promote the bioavailability of active compounds, indicating natural nanoparticles of decoctions play an important role in therapeutic effects.
Topics: Animals; Rats; Biological Availability; Chromatography, Liquid; Spectroscopy, Fourier Transform Infrared; Tandem Mass Spectrometry; Nanoparticles; Caffeic Acids; Disaccharides; Spermine; Stilbenes
PubMed: 38617795
DOI: 10.2147/IJN.S449268 -
International Journal of Medical... 2024Dysregulation of cellular metabolism is a key marker of cancer, and it is suggested that metabolism should be considered as a targeted weakness of colorectal cancer....
Dysregulation of cellular metabolism is a key marker of cancer, and it is suggested that metabolism should be considered as a targeted weakness of colorectal cancer. Increased polyamine metabolism is a common metabolic change in tumors. Thus, targeting polyamine metabolism for anticancer therapy, particularly polyamine blockade therapy, has gradually become a hot topic. Quercetin-3-methyl ether is a natural compound existed in various plants with diverse biological activities like antioxidant and antiaging. Here, we reported that Quercetin-3-methyl ether inhibits colorectal cancer cell viability, and promotes apoptosis in a dose-dependent and time-dependent manner. Intriguingly, the polyamine levels, including spermidine and spermine, in colorectal cancer cells were reduced upon treatment of Quercetin-3-methyl ether. This is likely resulted from the downregulation of SMOX, a key enzyme in polyamine metabolism that catalyzes the oxidation of spermine to spermidine. These findings suggest Quercetin-3-methyl ether decreases cellular polyamine level by suppressing SMOX expression, thereby inducing colorectal cancer cell apoptosis. Our results also reveal a correlation between the anti-tumor activity of Quercetin-3-methyl ether and the polyamine metabolism modulation, which may provide new insights into a better understanding of the pharmacological activity of Quercetin-3-methyl ether and how it reprograms cellular polyamine metabolism.
Topics: Humans; Polyamines; Spermidine; Spermine; Apoptosis; Biological Products; Colorectal Neoplasms; Quercetin
PubMed: 38617002
DOI: 10.7150/ijms.93903 -
International Journal of Molecular... Apr 2024D-arginine (D-Arg) can promote embryogenic callus (EC) proliferation and increase the rate of somatic embryo induction of litchi ( Sonn.), yet the mechanism underlying...
Physiological, Metabolic, and Transcriptomic Analyses Reveal Mechanisms of Proliferation and Somatic Embryogenesis of Litchi ( Sonn.) Embryogenic Callus Promoted by D-Arginine Treatment.
D-arginine (D-Arg) can promote embryogenic callus (EC) proliferation and increase the rate of somatic embryo induction of litchi ( Sonn.), yet the mechanism underlying the processes is incompletely understood. To investigate the mechanism, physiological responses of polyamines (PAs) [putrescine (Put), spermidine (Spd), and spermine (Spm)] were investigated for D-Arg-treated litchi EC and enzyme activity related to polyamine metabolism, plant endogenous hormones, and polyamine- and embryogenic-related genes were explored. Results showed that the exogenous addition of D-Arg reduces the activity of diamine oxidase (DAO) and polyamine oxidase (PAO) in EC, reduces the production of HO, promotes EC proliferation, and increases the (Spd + Spm)/Put ratio to promote somatic embryo induction. Exogenous D-Arg application promoted somatic embryogenesis (SE) by increasing indole-3-acetyl glycine (IAA-Gly), kinetin-9-glucoside (K9G), and dihydrozeatin-7-glucoside (DHZ7G) levels and decreasing trans-zeatin riboside (tZR), N-[(-)-jasmonoyl]-(L)-valine (JA-Val), jasmonic acid (JA), and jasmonoyl-L-isoleucine (Ja-ILE) levels on 18 d, as well as promoting cell division and differentiation. The application of exogenous D-Arg regulated EC proliferation and somatic embryo induction by altering gene expression levels of the WRKY family, AP2/ERF family, C3H family, and C2H2 family. These results indicate that exogenous D-Arg could regulate the proliferation of EC and the SE induction of litchi by changing the biosynthesis of PAs through the alteration of gene expression pattern and endogenous hormone metabolism.
Topics: Litchi; Hydrogen Peroxide; Embryonic Development; Polyamines; Spermidine; Putrescine; Spermine; Arginine; Cell Division; Glucosides; Cyclopentanes; Isoleucine; Oxylipins
PubMed: 38612774
DOI: 10.3390/ijms25073965 -
Foods (Basel, Switzerland) Mar 2024A new chitosan-based protective film containing rosemarinic acid (0.282% /) has been elaborated. The film was formed from a water-oil emulsion system and applied to...
A new chitosan-based protective film containing rosemarinic acid (0.282% /) has been elaborated. The film was formed from a water-oil emulsion system and applied to poultry meat samples using a dip-coating technique. Various physicochemical parameters of the coatings, such as thickness, Young's modulus, elongation at break, water vapor transmission rates, and antioxidant activity, were tested with free-standing film samples peeled from a Petri dish. Compared to neat chitosan films obtained similarly, new films cast from the emulsion showed significantly better elasticity (Young's modulus was diminished from 1458 MPa to about 29 MPa). Additionally, barrier properties for moisture transition decreased from 7.3 to 5.8 g mm m day kPa. The coated poultry samples were subsequently evaluated in juxtaposition with uncoated ones in a storage test. Levels of selected biogenic amines (histamine, tyramine, tryptamine, phenylethylamine, putrescine, cadaverine, spermine, and spermidine), total bacterial count, and lipid oxidation levels in the meat samples were analyzed during storage at 4 °C (up to 96 h). The results obtained for the biogenic amines, total bacterial content, calculated biogenic amine index, and the ratio of spermidine to spermine in meat samples suggest the advantage of the proposed coatings with rosmarinic acid in protecting poultry meat against environmental factors and rapid spoilage.
PubMed: 38611289
DOI: 10.3390/foods13070985 -
Advanced Science (Weinheim,... Jun 2024The inflammatory response is a key factor affecting tissue regeneration. Inspired by the immunomodulatory role of spermidine, an injectable double network hydrogel...
The inflammatory response is a key factor affecting tissue regeneration. Inspired by the immunomodulatory role of spermidine, an injectable double network hydrogel functionalized with spermidine (DN-SPD) is developed, where the first and second networks are formed by dynamic imine bonds and non-dynamic photo-crosslinked bonds respectively. The single network hydrogel before photo-crosslinking exhibits excellent injectability and thus can be printed and photo-crosslinked in situ to form double network hydrogels. DN-SPD hydrogel has demonstrated desirable mechanical properties and tissue adhesion. More importantly, an "operando" comparison of hydrogels loaded with spermidine or diethylenetriamine (DETA), a sham molecule resembling spermidine, has shown similar physical properties, but quite different biological functions. Specifically, the outcomes of 3 sets of in vivo animal experiments demonstrate that DN-SPD hydrogel can not only reduce inflammation caused by implanted exogenous biomaterials and reactive oxygen species but also promote the polarization of macrophages toward regenerative M2 phenotype, in comparison with DN-DETA hydrogel. Moreover, the immunoregulation by spermidine can also translate into faster and more natural healing of both acute wounds and diabetic wounds. Hence, the local administration of spermidine affords a simple but elegant approach to attenuate foreign body reactions induced by exogenous biomaterials to treat chronic refractory wounds.
Topics: Spermidine; Animals; Wound Healing; Hydrogels; Inflammation; Mice; Disease Models, Animal; Diabetes Mellitus, Experimental; Male; Biocompatible Materials
PubMed: 38602439
DOI: 10.1002/advs.202310162 -
Food Technology and Biotechnology Mar 2024Ageing is a biochemical, metabolic and genetic physiological phenomenon. The suppression of melanin biosynthesis, evident in the greying of the hair, is a hallmark of...
RESEARCH BACKGROUND
Ageing is a biochemical, metabolic and genetic physiological phenomenon. The suppression of melanin biosynthesis, evident in the greying of the hair, is a hallmark of ageing resulting from translation failure, reduced enzyme activity and cellular senescence. Putrescine, the smallest member of the polyamine family and an organic chemical, is present in living mammalian cells and plays a crucial role in regulating skin melanogenesis. Therefore, the purpose of this study is to explore the effect of putrescine on the signalling pathways of melanogenesis in melanoma cells.
EXPERIMENTAL APPROACH
Melanin production capacity of putrescine was analysed using a tyrosinase activity assay. To assess the cell viability of B16F1 cells exposed to putrescine, a tetrazolium dye MTT assay was performed. The effect of putrescine on melanin synthesis in the presence of HO was evaluated using various assays in B16F1 cells. The effect of putrescine on melanin production in B16F1 cells was determined using a specific melanin production assay. Gene expression was analysed using real-time polymerase chain reaction (RT-PCR). Furthermore, the effect of putrescine on the expression of proteins related to melanin production in the cells treated with HO was analysed by immunofluorescence and Western blot analysis.
RESULTS AND CONCLUSIONS
Putrescine increased tyrosinase activity and showed no cytotoxicity in B16F1 cells. In addition, putrescine effectively scavenged HO, as shown by the reduction of intracellular HO amounts in 2',7'-dichlorofluorescin diacetate analysis, and promoted melanin production in living cells. The stimulation of melanogenesis by putrescine was attributed to the increased expression of , , and genes. Immunofluorescence assays revealed that putrescine enhanced the expression of proteins associated with melanogenesis and upregulated TYR, TRP-1 and TRP-2 the microphthalmia-associated transcription factor (MITF) and increased the expression of methionine sulfoxide reductases A (MSRA) and B (MSRB) in the cells treated with HO, effectively promoting melanogenesis. These results suggest that putrescine can be used to stimulate melanin synthesis.
NOVELTY AND SCIENTIFIC CONTRIBUTION
This is the first study to investigate the effect of putrescine on the signalling pathways of melanogenesis in B16F1 melanoma cells. The results confirm that putrescine can promote melanogenesis through the expression of TYR, TRP-1 and TRP-2 the MITF in cells treated with HO. Putrescine can be used exclusively as a cosmetic product to prevent premature greying of hair.
PubMed: 38601964
DOI: 10.17113/ftb.62.01.24.8120