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Cells Jan 2021Circulating extracellular DNA (ecDNA) is known to worsen the outcome of many diseases. ecDNA released from neutrophils during infection or inflammation is present in the...
Circulating extracellular DNA (ecDNA) is known to worsen the outcome of many diseases. ecDNA released from neutrophils during infection or inflammation is present in the form of neutrophil extracellular traps (NETs). It has been shown that higher ecDNA concentration occurs in a number of inflammatory diseases including inflammatory bowel disease (IBD). Enzymes such as peptidyl arginine deiminases (PADs) are crucial for NET formation. We sought to describe the dynamics of ecDNA concentrations and fragmentation, along with NETosis during a mouse model of chemically induced colitis. Plasma ecDNA concentration was highest on day seven of dextran sulfate sodium (DSS) intake and the increase was time-dependent. This increase correlated with the percentage of cells undergoing NETosis and other markers of disease activity. Relative proportion of nuclear ecDNA increased towards more severe colitis; however, absolute amount decreased. In colon explant medium, the highest concentration of ecDNA was on day three of DSS consumption. Early administration of PAD4 inhibitors did not alleviate disease activity, but lowered the ecDNA concentration. These results uncover the biological characteristics of ecDNA in IBD and support the role of ecDNA in intestinal inflammation. The therapeutic intervention aimed at NETs and/or nuclear ecDNA has yet to be fully investigated.
Topics: Animals; Biomarkers; Colitis; DNA; DNA, Mitochondrial; Deoxyribonucleases; Dextran Sulfate; Endoscopy; Extracellular Space; Extracellular Traps; Inflammation; Intestinal Mucosa; Intestines; Mice, Inbred C57BL; Ornithine; Protein-Arginine Deiminase Type 4; Severity of Illness Index; Streptonigrin; Mice
PubMed: 33418977
DOI: 10.3390/cells10010081 -
Food Microbiology Oct 2023Salmonella is known to survive in raw/pasteurized milk and cause foodborne outbreaks. Lactoferrin, present in milk from all animal sources, is an iron-binding...
Salmonella is known to survive in raw/pasteurized milk and cause foodborne outbreaks. Lactoferrin, present in milk from all animal sources, is an iron-binding glycoprotein that limits the availability of iron to pathogenic bacteria. Despite the presence of lactoferrins, Salmonella can grow in milk obtained from different animal sources. However, the mechanism by which Salmonella overcomes iron scarcity induced by lactoferrin in milk is not evaluated yet. Salmonella employs the DNA binding transcriptional regulator Fur (ferric update regulator) to mediate iron uptake during survival in iron deplete conditions. To understand the importance of Fur in Salmonella milk growth, we profiled the growth of Salmonella Typhimurium Δfur (ST4/74Δfur) in both bovine and camel milk. ST4/74Δfur was highly inhibited in milk compared to wild-type ST4/74, confirming the importance of Fur mediated regulation of iron metabolism in Salmonella milk growth. We further studied the biology of ST4/74Δfur to understand the importance of iron metabolism in Salmonella milk survival. Using increasing concentrations of FeCl, and the antibiotic streptonigrin we show that iron accumulates in the cytoplasm of ST4/74Δfur. We hypothesized that the accumulated iron could activate oxidative stress via Fenton's reaction leading to growth inhibition. However, the inhibition of ST4/74Δfur in milk was not due to Fenton's reaction, but due to the 'iron scarce' conditions of milk and microaerophilic incubation conditions which made the presence of the fur gene indispensable for Salmonella milk growth. Subsequently, survival studies of 14 other transcriptional mutants of ST4/74 in milk confirmed that RpoE-mediated response to extracytoplasmic stress is also important for the survival of Salmonella in milk. Though we have data only for fur and rpoE, many other Salmonella transcriptional factors could play important roles in the growth of Salmonella in milk, a theme for future research on Salmonella milk biology. Nevertheless, our data provide early insights into the biology of milk-associated Salmonella.
Topics: Animals; Cattle; Salmonella typhimurium; Lactoferrin; Repressor Proteins; Iron; Milk; Bacterial Proteins; Gene Expression Regulation, Bacterial
PubMed: 37567619
DOI: 10.1016/j.fm.2023.104326 -
Marine Drugs Mar 2019Two new piperazine-triones lansai E and F (, ), together with four known secondary metabolites lansai D (), 1--methyl-()-albonoursin (), imidazo[4,5-]-1,2,4-triazine (),...
Two new piperazine-triones lansai E and F (, ), together with four known secondary metabolites lansai D (), 1--methyl-()-albonoursin (), imidazo[4,5-]-1,2,4-triazine (), and streptonigrin () were isolated from a deep-sea-derived sp. strain SMS636. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR. Compound exhibited moderate antibacterial activities against and methicillin resistant (MRSA) with Minimum Inhibitory Concentration (MIC) values of 12.5 and 25 μg/mL, respectively. Compound displayed significant antibacterial activities against , MRSA and Bacillus Calmette-Guérin (BCG) with MIC values of 0.78, 0.78 and 1.25 μg/mL, respectively.
Topics: Anti-Bacterial Agents; Candida albicans; Escherichia coli; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Piperazine; Pseudomonas aeruginosa; Staphylococcus aureus; Streptomycetaceae
PubMed: 30901830
DOI: 10.3390/md17030186 -
Cx32 suppresses extrinsic apoptosis in human cervical cancer cells via the NF‑κB signalling pathway.International Journal of Oncology Oct 2017Tumour necrosis factor α (TNFα) and TNF‑related apoptosis inducing ligand (TRAIL) usually trigger either survival or apoptosis signals in various cell types, and...
Tumour necrosis factor α (TNFα) and TNF‑related apoptosis inducing ligand (TRAIL) usually trigger either survival or apoptosis signals in various cell types, and nuclear factor κB (NF‑κB) is a key factor that regulates their biological effects. Connexin 32 (Cx32) is a gap junction (GJ) protein that plays vital roles in tumourigenesis and tumour progression. Our previous study explored abnormal Cx32 expression in para‑nuclear areas, exacerbated prognostic parameters and suppressed streptonigrin/cisplatin-induced apoptosis in human cervical cancer (CaCx) cells. In this study, we investigated the role of Cx32 in the extrinsic apoptosis pathway of CaCx cells. In transgenic HeLa cells and C-33A cells, Cx32 expression was manipulated using doxycycline or Cx32 siRNA. GJ inhibitors or low density culturing was used to change the status of gap junction intracellular communication (GJIC). We found that apoptosis induced by TNFα and TRAIL was suppressed by Cx32 expression despite the presence or absense of GJIC. We also found that Cx32 upregulated the expression of nuclear NF‑κB and its downstream targets c-IAP1, MMP‑2, and MMP‑9 in HeLa‑Cx32 and C-33A cells. Following our previous study design, our clinical data showed that NF‑κB and MMP‑2 levels increased in human CaCx specimens with high Cx32 expression compared to levels in para‑carcinoma of cervical specimens. SC75741 and JSH-23, NF‑кB signalling pathway inhibitors, inhibited the anti-apoptotic effects of Cx32. In conclusion, Cx32 suppressed TNFα /TRAIL-induced extrinsic apoptosis by upregulating the NF‑κB signalling pathway. This study demonstrates a novel mechanism for Cx32's anti-apoptotic effect and provides a reasonable explanation for the pro-tumour effect of Cx32 in human CaCx cells.
Topics: Apoptosis; Cell Line, Tumor; Connexins; Doxycycline; Female; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; NF-kappa B; RNA, Small Interfering; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha; Uterine Cervical Neoplasms; Gap Junction beta-1 Protein
PubMed: 28902345
DOI: 10.3892/ijo.2017.4106 -
Molecules (Basel, Switzerland) Sep 2022Hybrids 1,4-quinone with quinoline were obtained by connecting two active structures through an oxygen atom. This strategy allows to obtain new compounds with a high...
Hybrids 1,4-quinone with quinoline were obtained by connecting two active structures through an oxygen atom. This strategy allows to obtain new compounds with a high biological activity and suitable bioavailability. Newly synthesized compounds were characterized by various spectroscopic methods. The enzymatic assay used showed that these compounds were a suitable DT-diaphorase (NQO1) substrates as evidenced by increasing enzymatic conversion rates relative to that of streptonigrin. Hybrids were tested in vitro against a panel of human cell lines including melanoma, breast, and lung cancers. They showed also a high cytotoxic activity depending on the type of 1,4-quinone moiety and the applied tumor cell lines. It was found that cytotoxic activity of the studied hybrids was increasing against the cell lines with higher NQO1 protein level, such as breast (MCF-7 and T47D) and lung (A549) cancers. Selected hybrids were tested for the transcriptional activity of the gene encoding a proliferation marker (H3 histone), cell cycle regulators (p53 and p21) and the apoptosis pathway (BCL-2 and BAX). The molecular docking was used to examine the probable interaction between the hybrids and NQO1 protein.
Topics: Antineoplastic Agents; Apoptosis; Benzoquinones; Cell Line, Tumor; Drug Screening Assays, Antitumor; Histones; Humans; Hydroxyquinolines; Molecular Docking Simulation; NAD(P)H Dehydrogenase (Quinone); Oxygen; Quinolines; Quinones; Streptonigrin; Tumor Suppressor Protein p53; bcl-2-Associated X Protein
PubMed: 36234741
DOI: 10.3390/molecules27196206 -
Bioorganic Chemistry Jan 2021In this research, betulin derivatives were bonded to the 1,4-quinone fragment by triazole linker. Furthermore, the enzymatic assay used has shown that these compounds...
In this research, betulin derivatives were bonded to the 1,4-quinone fragment by triazole linker. Furthermore, the enzymatic assay used has shown that these compounds are a good DT-diaphorase (NQO1) substrates as evidenced by increasing enzymatic conversion rates relative to that of streptonigrin. The anticancer activities of the hybrids were tested against a panel of human cell lines, like: melanoma, ovarian, breast, colon, and lung cancers. The structure-activity relationship showed that the activity depends on the type of 1,4-quinone moiety and the tumor cell lines used. It was also found that the anticancer effects were increasing against the cell line with higher NQO1 protein level, like: breast (T47D, MCF-7), colon (Caco-2), and lung (A549) cancers. The transcriptional activity of the gene encoding a proliferation marker (H3 histone), cell cycle regulators (p53 and p21) and apoptosis pathway (BCL-2 and BAX) for selected compounds were determined. The molecular docking study was carried out to examine the interaction between the hybrids and NQO1 enzyme. The computational simulation showed that the type of the 1,4-quinone moiety influences location of the compound in the active site of the enzyme. It is worth noting that the study of new hybrids of betulin as substrate for NQO1 protein may lead to new medical therapeutic applications in the future.
Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Design; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Humans; Molecular Docking Simulation; Molecular Structure; NAD(P)H Dehydrogenase (Quinone); Quinones; Structure-Activity Relationship; Substrate Specificity; Triterpenes
PubMed: 33272711
DOI: 10.1016/j.bioorg.2020.104478 -
Journal of Cell Science Sep 2017This study was designed to identify bioactive compounds that alter the cellular shape of the fission yeast by affecting functions involved in the cell cycle or cell...
This study was designed to identify bioactive compounds that alter the cellular shape of the fission yeast by affecting functions involved in the cell cycle or cell morphogenesis. We used a multidrug-sensitive fission yeast strain, SAK950 to screen a library of 657 actinomycete bacteria and identified 242 strains that induced eight different major shape phenotypes in These include the typical cell cycle-related phenotype of elongated cells, and the cell morphology-related phenotype of rounded cells. As a proof of principle, we purified four of these activities, one of which is a novel compound and three that are previously known compounds, leptomycin B, streptonigrin and cycloheximide. In this study, we have also shown novel effects for two of these compounds, leptomycin B and cycloheximide. The identification of these four compounds and the explanation of the phenotypes in terms of their known, or predicted bioactivities, confirm the effectiveness of this approach.
Topics: Actinomyces; Biological Products; Cell Shape; Checkpoint Kinase 1; Cycloheximide; DNA Damage; Drug Evaluation, Preclinical; Fatty Acids, Unsaturated; Phenotype; Schizosaccharomyces; Spectrometry, Mass, Electrospray Ionization
PubMed: 28775153
DOI: 10.1242/jcs.194571 -
The Journal of Pharmacology and... Jun 2016β-Lapachone [β-lap; 3,4-dihydro-2,2-dimethyl-2H-naphthol[1,2-b]pyran-5,6-dione] is a novel anticancer drug currently under investigation in phase I/II clinical trials....
UNLABELLED
β-Lapachone [β-lap; 3,4-dihydro-2,2-dimethyl-2H-naphthol[1,2-b]pyran-5,6-dione] is a novel anticancer drug currently under investigation in phase I/II clinical trials. However, the mechanism underlying its clinical efficacy remains unclear. In this study, we found that β-lap provoked the cleavage of heat shock protein 90 (Hsp90) in
NAD(P)H
quinone oxidoreductase-1 (NQO1)-expressing lung and prostate cancer cells as well as in primary human umbilical vein endothelial cells (HUVECs). These actions of β-lap were different from that of the conventional Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin. As a consequence of Hsp90 cleavage, Hsp90-associated oncoproteins, such as receptor-interacting protein, Raf-1, AKT, and CDK4, were degraded in treated cancer cells, and key receptor tyrosine kinases such as vascular endothelial cell growth factor receptor-2 and Her-2 were degraded in treated HUVECs through a proteasomal system. Further results revealed that specific inhibitors of NQO1 and reactive oxygen species could dramatically reduce β-lap-mediated Hsp90 cleavage. In addition to its cytotoxicity, β-lap effectively inhibited angiogenesis by suppressing tube formation and the invasion of HUVECs in vitro, rat aortic microvascular sprouts ex vivo, and mouse corneal neovascularization in vivo. Furthermore, β-lap markedly suppressed the growth and angiogenesis of human lung cancer xenografts in nude mice and decreased the levels of receptor-interacting protein, AKT, CDK4, and CD31 in the solid tumors. Unlike other NQO1-dependent cytotoxic quinones, such as streptonigrin, menadione, mitomycin, and 17-allylamino-17-demethoxygeldanamycin, β-lap was the only agent that could cause Hsp90 cleavage. Taken together, our results suggest a crucial mechanism underlying the antitumor efficacy of β-lap.
Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Aorta; Cell Line, Tumor; Cell Proliferation; HSP90 Heat-Shock Proteins; Humans; Male; Mice; NAD(P)H Dehydrogenase (Quinone); Naphthoquinones; Neovascularization, Pathologic; Oncogene Proteins; Oxidative Stress; Proteasome Endopeptidase Complex; Protein Stability; Proteolysis; Rats; Xenograft Model Antitumor Assays
PubMed: 27048660
DOI: 10.1124/jpet.116.232694 -
Organic & Biomolecular Chemistry Dec 2018Streptonigrin (STN, 1) is a highly functionalized aminoquinone alkaloid antibiotic with broad and potent antitumor activity. Previous isotope-labelling and genetic...
Streptonigrin (STN, 1) is a highly functionalized aminoquinone alkaloid antibiotic with broad and potent antitumor activity. Previous isotope-labelling and genetic studies suggested that a β-carboline alkaloid should be a key intermediate of STN biosynthesis and formed via a Pictet-Spengler (PS) reaction. Herein, StnK2 was biochemically characterized to be a Pictet-Spenglerase (PSase) catalysing the formation of a tetrahydro-β-carboline (TH-βC) scaffold from (2S,3S)-β-methyl tryptophan and d-erythrose-4-phosphate. StnK2 can tolerate the alteration of tryptophan but only accept d-erythrose-4-phosphate as the aldehyde substrate, and StnK2 was identified to be R-specific for the newly formed chiral center. This work increases the diversities of Pictet-Spenglerase in nature and set a stage for the generation of streptonigrin derivatives by precursor-directed pathway engineering based on the flexible substrate selectivity of StnK2.
Topics: Antibiotics, Antineoplastic; Biosynthetic Pathways; Carbolines; Stereoisomerism; Streptomyces; Streptonigrin; Substrate Specificity; Tryptophan
PubMed: 30483694
DOI: 10.1039/c8ob02710b -
Emerging Microbes & Infections 2019Transition metals are nutrients essential for life. However, an excess of metals can be toxic to cells, and host-imposed metal toxicity is an important mechanism for...
Transition metals are nutrients essential for life. However, an excess of metals can be toxic to cells, and host-imposed metal toxicity is an important mechanism for controlling bacterial infection. Accordingly, bacteria have evolved metal efflux systems to maintain metal homeostasis. Here, we established that PmtA functions as a ferrous iron [Fe(II)] and cobalt [Co(II)] efflux pump in , an emerging zoonotic pathogen responsible for severe infections in both humans and pigs. expression is induced by Fe(II), Co(II), and nickel [Ni(II)], whereas PmtA protects against Fe(II) and ferric iron [Fe(III)]-induced bactericidal effect, as well as Co(II) and zinc [Zn(II)]-induced bacteriostatic effect. In the presence of elevated concentrations of Fe(II) and Co(II), Δ accumulates high levels of intracellular iron and cobalt, respectively. Δ is also more sensitive to streptonigrin, a Fe(II)-activated antibiotic. Furthermore, growth defects of Δ under Fe(II) or Co(II) excess conditions can be alleviated by manganese [Mn(II)] supplementation. Finally, PmtA plays a role in tolerance to HO-induced oxidative stress, yet is not involved in the virulence of in mice. Together, these data demonstrate that PmtA acts as a Fe(II) and Co(II) efflux pump, and contributes to oxidative stress resistance.
Topics: Bacterial Proteins; Biological Transport, Active; Cobalt; Gene Deletion; Iron; Methyltransferases; Streptococcus suis; Trace Elements
PubMed: 31469035
DOI: 10.1080/22221751.2019.1660233