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1.
Proc Natl Acad Sci U S A ; 120(52): e2306863120, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38127978

RESUMO

The gut microbiota is a considerable source of biologically active compounds that can promote intestinal homeostasis and improve immune responses. Here, we used large expression libraries of cloned metagenomic DNA to identify compounds able to sustain an anti-inflammatory reaction on host cells. Starting with a screen for NF-κB activation, we have identified overlapping clones harbouring a heterodimeric ATP-binding cassette (ABC)-transporter from a Firmicutes. Extensive purification of the clone's supernatant demonstrates that the ABC-transporter allows for the efficient extracellular accumulation of three muropeptide precursor, with anti-inflammatory properties. They induce IL-10 secretion from human monocyte-derived dendritic cells and proved effective in reducing AIEC LF82 epithelial damage and IL-8 secretion in human intestinal resections. In addition, treatment with supernatants containing the muropeptide precursor reduces body weight loss and improves histological parameters in Dextran Sulfate Sodium (DSS)-treated mice. Until now, the source of peptidoglycan fragments was shown to come from the natural turnover of the peptidoglycan layer by endogenous peptidoglycan hydrolases. This is a report showing an ABC-transporter as a natural source of secreted muropeptide precursor and as an indirect player in epithelial barrier strengthening. The mechanism described here might represent an important component of the host immune homeostasis.


Assuntos
Colite , Microbioma Gastrointestinal , Humanos , Camundongos , Animais , Peptidoglicano/metabolismo , Intestinos/patologia , Inflamação/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Anti-Inflamatórios/metabolismo , Sulfato de Dextrana , Colite/metabolismo , Modelos Animais de Doenças , Colo/metabolismo , Camundongos Endogâmicos C57BL
2.
Proc Natl Acad Sci U S A ; 117(32): 19168-19177, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719135

RESUMO

The emergence of superbugs developing resistance to antibiotics and the resurgence of microbial infections have led scientists to start an antimicrobial arms race. In this context, we have previously identified an active RiPP, the Ruminococcin C1, naturally produced by Ruminococcus gnavus E1, a symbiont of the healthy human intestinal microbiota. This RiPP, subclassified as a sactipeptide, requires the host digestive system to become active against pathogenic Clostridia and multidrug-resistant strains. Here we report its unique compact structure on the basis of four intramolecular thioether bridges with reversed stereochemistry introduced posttranslationally by a specific radical-SAM sactisynthase. This structure confers to the Ruminococcin C1 important clinical properties including stability to digestive conditions and physicochemical treatments, a higher affinity for bacteria than simulated intestinal epithelium, a valuable activity at therapeutic doses on a range of clinical pathogens, mediated by energy resources disruption, and finally safety for human gut tissues.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Clostridiales/química , Peptídeos/química , Peptídeos/farmacologia , Antibacterianos/isolamento & purificação , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Peptídeos/isolamento & purificação
3.
Int J Mol Sci ; 22(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806791

RESUMO

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Peptídeos/farmacologia , Antibacterianos/química , Antifúngicos/farmacologia , Bacteriocinas/química , Biofilmes/efeitos dos fármacos , Clostridiales/metabolismo , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/microbiologia , Clostridium perfringens/efeitos dos fármacos , Humanos , Peptídeos/química , Processamento de Proteína Pós-Traducional
4.
Molecules ; 26(4)2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562701

RESUMO

Chronic cerebral ischemia with a notable long-term cessation of blood supply to the brain tissues leads to sensorimotor defects and short- and long-term memory problems. Neuroprotective agents are used in an attempt to save ischemic neurons from necrosis and apoptosis, such as the antioxidant agent Eucalyptus. Numerous studies have demonstrated the involvement of the renin-angiotensin system in the initiation and progression of cardiovascular and neurodegenerative diseases. Candesartan is a drug that acts as an angiotensin II receptor 1 blocker. We established a rat model exhibiting sensorimotor and cognitive impairments due to chronic cerebral ischemia induced by the ligation of the right common carotid artery. Wistar male rats were randomly divided into five groups: Sham group, Untreated Ligated group, Ischemic group treated with Eucalyptus (500 mg/kg), Ischemic group treated with Candesartan (0.5 mg/kg), and Ischemic group treated with a combination of Eucalyptus and Candesartan. To evaluate the sensorimotor disorders, we performed the beam balance test, the beam walking test, and the modified sticky test. Moreover, the object recognition test and the Morris water maze test were performed to assess the memory disorders of the rats. The infarct rat brain regions were subsequently stained using the triphenyltetrazolium chloride staining technique. The rats in the Sham group had normal sensorimotor and cognitive functions without the appearance of microscopic ischemic brain lesions. In parallel, the untreated Ischemic group showed severe impaired neurological functions with the presence of considerable brain infarctions. The treatment of the Ischemic group with a combination of both Eucalyptus and Candesartan was more efficient in improving the sensorimotor and cognitive deficits (p < 0.001) than the treatment with Eucalyptus or Candesartan alone (p < 0.05), by the comparison to the non-treated Ischemic group. Our study shows that the combination of Eucalyptus and Candesartan could decrease ischemic brain injury and improve neurological outcomes.


Assuntos
Anti-Hipertensivos/farmacologia , Antioxidantes/farmacologia , Benzimidazóis/farmacologia , Compostos de Bifenilo/farmacologia , Isquemia Encefálica/tratamento farmacológico , Eucalyptus/química , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Tetrazóis/farmacologia , Animais , Anti-Hipertensivos/uso terapêutico , Antioxidantes/uso terapêutico , Benzimidazóis/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Peso Corporal/efeitos dos fármacos , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Artéria Carótida Primitiva/efeitos dos fármacos , Artéria Carótida Primitiva/patologia , Doença Crônica , Interações Medicamentosas , Teste do Labirinto Aquático de Morris/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Ratos , Reconhecimento Psicológico/efeitos dos fármacos , Tetrazóis/uso terapêutico
5.
Arch Toxicol ; 93(4): 1039-1049, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30854615

RESUMO

Trefoil factors (TFFs) are bioactive peptides expressed by several epithelia, including the intestine, where they regulate key functions such as tissue regeneration, barrier function and inflammation. Although food-associated mycotoxins, including deoxynivalenol (DON), are known to impact many intestinal functions, modulation of TFFs during mycotoxicosis has never been investigated. Here, we analyzed the effect of DON on TFFs expression using both human goblet cells (HT29-16E cells) and porcine intestinal explants. Results showed that very low doses of DON (nanomolar range) inhibit the secretion of TFFs by human goblet cells (IC50 of 361, 387 and 243 nM for TFF1, 2 and 3, respectively) and prevent wound healing. RT-qPCR analysis demonstrated that the inhibitory effect of DON is related to a suppression of TFFs mRNA expression. Experiments conducted on porcine intestinal explants confirmed the results obtained on cells. Finally, the use of specific inhibitors of signal pathways demonstrated that DON-mediated suppression of TFFs expression mainly involved Protein Kinase R and the MAP kinases (MAPK) p38 and ERK1/2. Taken together, our results show for the first time that at very low doses, DON suppresses the expression and production of intestinal TFFs and alters wound healing. Given the critical role of TFFs in tissue repair, our results suggest that DON-mediated suppression of TFFs contributes to the alterations of intestinal integrity the caused by this toxin.


Assuntos
Expressão Gênica/efeitos dos fármacos , Células Caliciformes/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Fator Trefoil-3/genética , Tricotecenos/toxicidade , Animais , Células CACO-2 , Técnicas de Cultura de Células , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Caliciformes/imunologia , Células Caliciformes/metabolismo , Células HT29 , Humanos , Jejuno/imunologia , Jejuno/metabolismo , Suínos , Fator Trefoil-3/metabolismo
6.
Angew Chem Int Ed Engl ; 56(52): 16515-16520, 2017 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-29105983

RESUMO

Free-radical copolymerization of cyclic ketene acetals (CKAs) and vinyl ethers (VEs) was investigated as an efficient yet simple approach for the preparation of functional aliphatic polyesters. The copolymerization of CKA and VE was first predicted to be quasi-ideal by DFT calculations. The theoretical prediction was experimentally confirmed by the copolymerization of 2-methylene-1,3-dioxepane (MDO) and butyl vinyl ether (BVE), leading to rMDO =0.73 and rBVE =1.61. We then illustrated the versatility of this approach by preparing different functional polyesters: 1) copolymers functionalized by fluorescent probes; 2) amphiphilic copolymers grafted with poly(ethylene glycol) (PEG) side chains able to self-assemble into PEGylated nanoparticles; 3) antibacterial films active against Gram-positive and Gram-negative bacteria (including a multiresistant strain); and 4) cross-linked bioelastomers with suitable properties for tissue engineering applications.

7.
Chempluschem ; 88(5): e202300156, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37145031

RESUMO

This study investigates the site-directed immobilization of a hybrid catalyst bearing a biquinoline-based-Pd(II) complex (1) and a robust laccase within cavities of a silica foam to favor veratryl alcohol oxidation. We performed the grafting of 1 at a unique surface located lysine of two laccase variants, either at closed (1⊂UNIK157 ) or opposite position (1⊂UNIK71 ) of the enzyme oxidation site. After immobilization into the cavities of silica monoliths bearing hierarchical porosity, we show that catalytic activity is dependent on the orientation and loading of each hybrid, 1⊂UNIK157 being twice as active than 1⊂UNIK71 (203 TON vs 100 TON) when operating under continuous flow. These systems can be reused 5 times, with an operational activity remaining as high as 40 %. We show that the synergy between 1 and laccase can be tuned within the foam. This work is a proof of concept for controlling the organization of a heterogeneous hybrid catalyst using a Pd/laccase/silica foam.

8.
iScience ; 26(9): 107563, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37664601

RESUMO

In a scenario where the discovery of new molecules to fight antibiotic resistance is a public health concern, ribosomally synthesized and post-translationally modified peptides constitute a promising alternative. In this context, the Gram-positive human gut symbiont Ruminococcus gnavus E1 produces five sactipeptides, Ruminococcins C1 to C5 (RumC1-C5), co-expressed with two radical SAM maturases. RumC1 has been shown to be effective against various multidrug resistant Gram-positives clinical isolates. Here, after adapting the biosynthesis protocol to obtain the four mature RumC2-5 we then evaluate their antibacterial activities. Establishing first that both maturases exhibit substrate tolerance, we then observed a variation in the antibacterial efficacy between the five isoforms. We established that all RumCs are safe for humans with interesting multifunctionalities. While no synergies where observed for the five RumCs, we found a synergistic action with conventional antibiotics targeting the cell wall. Finally, we identified crucial residues for antibacterial activity of RumC isoforms.

9.
J Biol Chem ; 286(47): 40814-23, 2011 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-21931163

RESUMO

α-Galactosides are non-digestible carbohydrates widely distributed in plants. They are a potential source of energy in our daily food, and their assimilation by microbiota may play a role in obesity. In the intestinal tract, they are degraded by microbial glycosidases, which are often modular enzymes with catalytic domains linked to carbohydrate-binding modules. Here we introduce a bifunctional enzyme from the human intestinal bacterium Ruminococcus gnavus E1, α-galactosidase/sucrose kinase (AgaSK). Sequence analysis showed that AgaSK is composed of two domains: one closely related to α-galactosidases from glycoside hydrolase family GH36 and the other containing a nucleotide-binding motif. Its biochemical characterization showed that AgaSK is able to hydrolyze melibiose and raffinose to galactose and either glucose or sucrose, respectively, and to specifically phosphorylate sucrose on the C6 position of glucose in the presence of ATP. The production of sucrose-6-P directly from raffinose points toward a glycolytic pathway in bacteria, not described so far. The crystal structures of the galactosidase domain in the apo form and in complex with the product shed light onto the reaction and substrate recognition mechanisms and highlight an oligomeric state necessary for efficient substrate binding and suggesting a cross-talk between the galactose and kinase domains.


Assuntos
Metagenoma , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Ruminococcus/enzimologia , Sacarose/metabolismo , alfa-Galactosidase/metabolismo , Anaerobiose , Animais , Domínio Catalítico , Cristalografia por Raios X , Humanos , Intestinos/microbiologia , Modelos Moleculares , Dados de Sequência Molecular , Fosfotransferases (Aceptor do Grupo Álcool)/química , Multimerização Proteica , Estrutura Quaternária de Proteína , Rafinose/metabolismo , Ratos , Especificidade por Substrato , alfa-Galactosidase/química
10.
Biomolecules ; 11(11)2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34827611

RESUMO

Adhesion to the digestive mucosa is considered a key factor for bacterial persistence within the gut. In this study, we show that Ruminococcus gnavus E1 can express the radA gene, which encodes an adhesin of the MSCRAMMs family, only when it colonizes the gut. The RadA N-terminal region contains an all-ß bacterial Ig-like domain known to interact with collagens. We observed that it preferentially binds human immunoglobulins (IgA and IgG) and intestinal mucins. Using deglycosylated substrates, we also showed that the RadA N-terminal region recognizes two different types of motifs, the protein backbone of human IgG and the glycan structure of mucins. Finally, competition assays with lectins and free monosaccharides identified Galactose and N-Acetyl-Galactosamine motifs as specific targets for the binding of RadA to mucins and the surface of human epithelial cells.


Assuntos
Clostridiales , Mucinas , Polissacarídeos , Simbiose
11.
Microbiome ; 9(1): 176, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34425887

RESUMO

BACKGROUND: An Escherichia coli (E. coli) pathotype with invasive properties, first reported by Darfeuille-Michaud and termed adherent-invasive E. coli (AIEC), was shown to be prevalent in up to half the individuals with Crohn's Disease (CD), suggesting that these bacteria could be involved in the pathophysiology of CD. Among the genes related to AIEC pathogenicity, fim has the potential to generate an inflammatory reaction from the intestinal epithelial cells and macrophages, as it interacts with TLR4, inducing the production of inflammatory cytokines independently of LPS. Therefore, targeting the bacterial adhesion of FimH-expressing bacteria seems a promising therapeutic approach, consisting of disarming bacteria without killing them, representing a selective strategy to suppress a potentially critical trigger of intestinal inflammation, without disturbing the intestinal microbiota. RESULTS: We analyzed the metagenomic composition of the gut microbiome of 358 patients with CD from two different cohorts and characterized the presence of FimH-expressing bacteria. To assess the pathogenic role of FimH, we used human intestinal explants and tested a specific FimH blocker to prevent bacterial adhesion and associated inflammation. We observed a significant and disease activity-dependent enrichment of Enterobacteriaceae in the gut microbiome of patients with CD. Bacterial FimH expression was functionally confirmed in ileal biopsies from 65% of the patients with CD. Using human intestinal explants, we further show that FimH is essential for adhesion and to trigger inflammation. Finally, a specific FimH-blocker, TAK-018, inhibits bacterial adhesion to the intestinal epithelium and prevents inflammation, thus preserving mucosal integrity. CONCLUSIONS: We propose that TAK-018, which is safe and well tolerated in humans, is a promising candidate for the treatment of CD and in particular in preventing its recurrence. Video abstract.


Assuntos
Doença de Crohn , Infecções por Escherichia coli , Adesinas de Escherichia coli/genética , Escherichia coli , Proteínas de Fímbrias/genética , Humanos , Inflamação , Mucosa Intestinal
12.
Antibiotics (Basel) ; 9(7)2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32640578

RESUMO

The biological activities of berberine, a natural plant molecule, are known to be affected by structural modifications, mostly at position 9 and/or 13. A series of new 13-substituted berberine derivatives were synthesized and evaluated in term of antimicrobial activity using various microorganisms associated to human diseases. Contrarily to the original molecule berberine, several derivatives were found strongly active in microbial sensitivity tests against Mycobacterium, Candida albicans and Gram-positive bacteria, including naïve or resistant Bacillus cereus, Staphylococcus aureus and Streptococcus pyogenes with minimal inhibitory concentration (MIC) of 3.12 to 6.25 µM. Among the various Gram-negative strains tested, berberine's derivatives were only found active on Helicobacter pylori and Vibrio alginolyticus (MIC values of 1.5-3.12 µM). Cytotoxicity assays performed on human cells showed that the antimicrobial berberine derivatives caused low toxicity resulting in good therapeutic index values. In addition, a mechanistic approach demonstrated that, contrarily to already known berberine derivatives causing either membrane permeabilization, DNA fragmentation or interacting with FtsZ protein, active derivatives described in this study act through inhibition of the synthesis of peptidoglycan or RNA. Overall, this study shows that these new berberine derivatives can be considered as potent and safe anti-bacterial agents active on human pathogenic microorganisms, including ones resistant to conventional antibiotics.

13.
Front Immunol ; 10: 564, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30984172

RESUMO

Strong tight junctions and curtailed inflammatory responses under stressful conditions are key for optimal digestive health. Bacillus-based probiotics are increasingly being used to maintain broilers' health, but their mode of action is often not well-defined. In the present study we used Caco-2 cells as a model for intestinal epithelia and assessed the effect of three Bacillus-based probiotics on intestinal barrier function and intestinal inflammation. Experimental results showed that one of the three tested strains, Bs 29784, significantly reinforced intestinal barrier integrity under basal conditions through an up-regulation of the expression of tight junction's proteins, whereas the others had no or detrimental effects. When Caco-2 cells were pre-treated with Bacillus subtilis strains, the subsequent IL-8 release to various pro-inflammatory signals (IL-1ß, deoxynivalenol, or flagellin) was blunted compared to cells that had not been pretreated, but to a different extent depending on the strain of Bacillus used. Bs 29784, was able to significantly decrease IL-8 production in all stressed conditions tested. Mechanistically, Bs 29784 appeared to limit nuclear translocation of NF-κB during IL-1ß exposure by preventing IκB degradation. The effects of Bs 29784 were observed independently with supernatant and cells but in a lesser extent than with the combination, indicating that they can thus likely be attributed to both secreted metabolites and cell-associated compounds. Moreover, under inflammatory conditions, Bs 29784 significantly reduced the upregulation of iNOS protein levels further underlining its intestinal anti-inflammatory potential. Our data show that Bacillus-based probiotics may indeed improve digestive health by strengthening intestinal barrier and limiting inflammatory responses and that these properties are strain-dependent.


Assuntos
Bacillus subtilis/imunologia , Mucosa Intestinal , Probióticos , Proteínas de Junções Íntimas/imunologia , Junções Íntimas/imunologia , Células CACO-2 , Humanos , Inflamação/imunologia , Inflamação/microbiologia , Interleucina-1beta/imunologia , Interleucina-8/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia
14.
Toxins (Basel) ; 11(9)2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484420

RESUMO

Filamentous fungi, although producing noxious molecules such as mycotoxins, have been used to produce numerous drugs active against human diseases such as paclitaxel, statins, and penicillin, saving millions of human lives. Cyclodepsipeptides are fungal molecules with potentially adverse and positive effects. Although these peptides are not novel, comparative studies of their antimicrobial activity, toxicity, and mechanism of action are still to be identified. In this study, the fungal cyclohexadepsipeptides enniatin (ENN) and beauvericin (BEA) were assessed to determine their antimicrobial activity and cytotoxicity against human cells. Results showed that these peptides were active against Gram-positive bacteria, Mycobacterium, and fungi, but not against Gram-negative bacteria. ENN and BEA had a limited hemolytic effect, yet were found to be toxic at low doses to nucleated human cells. Both peptides also interacted with bacterial lipids, causing low to no membrane permeabilization, but induced membrane depolarization and inhibition of macromolecules synthesis. The structure-activity analysis showed that the chemical nature of the side chains present on ENN and BEA (either iso-propyl, sec-butyl, or phenylmethyl) impacts their interaction with lipids, antimicrobial action, and toxicity.


Assuntos
Anti-Infecciosos/farmacologia , Depsipeptídeos/farmacologia , Anti-Infecciosos/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Depsipeptídeos/química , Eritrócitos/efeitos dos fármacos , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Hemólise/efeitos dos fármacos , Humanos , Relação Estrutura-Atividade
15.
Microb Genom ; 5(4)2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30913025

RESUMO

The human gut microbiome plays an essential role in maintaining human health including in degradation of dietary fibres and carbohydrates further used as nutrients by both the host and the gut bacteria. Previously, we identified a polysaccharide utilization loci (PUL) involved in sucrose and raffinose family oligosaccharide (RFO) metabolism from one of the most common Firmicutes present in individuals, Ruminococcus gnavus E1. One of the enzymes encoded by this PUL was annotated as a putative sucrose phosphate phosphorylase (RgSPP). In the present study, we have in-depth characterized the heterologously expressed RgSPP as sucrose 6F-phosphate phosphorylase (SPP), expanding our knowledge of the glycoside hydrolase GH13_18 subfamily. Specifically, the enzymatic characterization showed a selective activity on sucrose 6F-phosphate (S6FP) acting both in phosphorolysis releasing alpha-d-glucose-1-phosphate (G1P) and alpha-d-fructose-6-phosphate (F6P), and in reverse phosphorolysis from G1P and F6P to S6FP. Interestingly, such a SPP activity had never been observed in gut bacteria before. In addition, a phylogenetic and synteny analysis showed a clustering and a strictly conserved PUL organization specific to gut bacteria. However, a wide prevalence and abundance study with a human metagenomic library showed a correlation between SPP activity and the geographical origin of the individuals and, thus, most likely linked to diet. Rgspp gene overexpression has been observed in mice fed with a high-fat diet suggesting, as observed for humans, that intestine lipid and carbohydrate microbial metabolisms are intertwined. Finally, based on the genomic environment analysis, in vitro and in vivo studies, results provide new insights into the gut microbiota catabolism of sucrose, RFOs and S6FP.


Assuntos
Clostridiales/enzimologia , Microbioma Gastrointestinal , Glicosídeo Hidrolases , Sacarose/análogos & derivados , Fosfatos Açúcares/metabolismo , Animais , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/classificação , Glicosídeo Hidrolases/genética , Humanos , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Especificidade por Substrato , Sacarose/metabolismo
16.
Sci Adv ; 5(9): eaaw9969, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31579822

RESUMO

A major public health challenge today is the resurgence of microbial infections caused by multidrug-resistant strains. Consequently, novel antimicrobial molecules are actively sought for development. In this context, the human gut microbiome is an under-explored potential trove of valuable natural molecules, such as the ribosomally-synthesized and post-translationally modified peptides (RiPPs). The biological activity of the sactipeptide subclass of RiPPs remains under-characterized. Here, we characterize an antimicrobial sactipeptide, Ruminococcin C1, purified from the caecal contents of rats mono-associated with Ruminococcus gnavus E1, a human symbiont. Its heterologous expression and post-translational maturation involving a specific sactisynthase establish a thioether network, which creates a double-hairpin folding. This original structure confers activity against pathogenic Clostridia and multidrug-resistant strains but no toxicity towards eukaryotic cells. Therefore, the Ruminococcin C1 should be considered as a valuable candidate for drug development and its producer strain R. gnavus E1 as a relevant probiotic for gut health enhancement.


Assuntos
Antibiose , Microbioma Gastrointestinal , Ruminococcus/fisiologia , Simbiose , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/química , Farmacorresistência Bacteriana Múltipla , Humanos , Proteólise , Ratos , Ruminococcus/efeitos dos fármacos
17.
Chem Phys Lipids ; 154(1): 33-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18486606

RESUMO

Caco-2 cells were used as a model for investigating and comparing the absorption of alpha-tocopherol (Tol) and alpha-tocopheryl acetate (Tac) solubilized in micelles based on a mixture of sodium taurocholate (NaTC) and oleic acid. Surprisingly, the uptake of Tac was found to be similar to that of Tol, and in both cases, the dose-response plots suggest that protein-mediated transport processes were involved. Moreover Tol or Tac were also secreted into the basolateral medium of Caco-2 cells but Tac was mainly hydrolyzed either prior to absorption or intracellularly. The solubilization of Tol or Tac by NaTC on the apical side of the cell monolayer is a prerequisite for the uptake process, although larger amounts of the bile salt are necessary to solubilize Tac than Tol. Caco-2 cells showed hydrolytic activity on Tac, and additional cholesterol esterase may be taken up by the cells, thus increasing the rates of intracellular hydrolysis of Tac. Based on our findings, a scheme is suggested accounting for the absorption of alpha-tocopheryl acetate by enterocytes.


Assuntos
Células CACO-2 , Micelas , Vitamina E/química , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/química , Absorção , Células CACO-2/química , Células CACO-2/metabolismo , Enterócitos/química , Enterócitos/metabolismo , Humanos , Hidrólise , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Microscopia Confocal , Modelos Biológicos , Solubilidade , Esterol Esterase/química , Esterol Esterase/metabolismo , Ácido Taurocólico/química , Ácido Taurocólico/metabolismo , Fatores de Tempo , Tocoferóis , Vitamina E/metabolismo , alfa-Tocoferol/metabolismo
18.
Eur J Med Chem ; 148: 306-313, 2018 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-29471119

RESUMO

A novel series of enediynes possessing pentafluorophenylsulfoxide have been developed. The innovative compounds possess antiproliferative activity against a broad panel of human cancer cells originating from breast, blood, lung, kidney, colon, prostate, pancreas or skin with IC50 ranging from 0.6 to 3.4 µM. The antiproliferative activity of enediynes in darkness is associated to their ability to compromise microtubule network. In addition, exposure to UV leads to double-stranded DNA cleavage caused by the newly synthesized molecules reducing further their IC50 in nanomolar range against human tumor cells, including chemo-resistant pancreatic cancer cells. Taken together, the examined data demonstrate that enediynes possessing pentafluorosulfoxide are promising molecules in the cancer therapy.


Assuntos
Antineoplásicos/química , Enedi-Inos/química , Sulfóxidos/química , Linhagem Celular Tumoral , DNA/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Humanos , Microtúbulos/efeitos dos fármacos , Raios Ultravioleta
19.
PLoS One ; 11(11): e0165420, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27812135

RESUMO

NOD2 contributes to the innate immune response and to the homeostasis of the intestinal mucosa. In response to its bacterial ligand, NOD2 interacts with RICK and activates the NF-κB and MAPK pathways, inducing gene transcription and synthesis of proteins required to initiate a balanced immune response. Mutations in NOD2 have been associated with an increased risk of Crohn's Disease (CD), a disabling inflammatory bowel disease (IBD). Because NOD2 signaling plays a key role in CD, it is important to further characterize the network of protein interacting with NOD2. Using yeast two hybrid (Y2H) screens, we identified new NOD2 interacting proteins (NIP). The primary interaction was confirmed by coimmunoprecipitation and/or bioluminescence resonance energy transfer (BRET) experiments for 11 of these proteins (ANKHD1, CHMP5, SDCCAG3, TRIM41, LDOC1, PPP1R12C, DOCK7, VIM, KRT15, PPP2R3B, and C10Orf67). These proteins are involved in diverse functions, including endosomal sorting complexes required for transport (ESCRT), cytoskeletal architecture and signaling regulation. Additionally, we show that the interaction of 8 NIPs is compromised with the 3 main CD associated NOD2 mutants (R702W, G908R and 1007fs). Furthermore, to determine whether these NOD2 protein partners could be encoded by IBD susceptibility genes, a transmission disequilibrium test (TDT) was performed on 101 single nucleotide polymorphisms (SNPs) and the main corresponding haplotypes in genes coding for 15 NIPs using a set of 343 IBD families with 556 patients. Overall this work did not increase the number of IBD susceptibility genes but extends the NOD2 protein interaction network and suggests that NOD2 interactome and signaling depend upon the NOD2 mutation profile in CD.


Assuntos
Doença de Crohn/genética , Doença de Crohn/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Mapeamento de Interação de Proteínas , Linhagem Celular , Humanos , Macrófagos/metabolismo , Mutação , NF-kappa B/genética , NF-kappa B/metabolismo , Proteína Adaptadora de Sinalização NOD2/genética , Polimorfismo de Nucleotídeo Único
20.
Mol Nutr Food Res ; 59(6): 1076-87, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25727397

RESUMO

SCOPE: The food-associated mycotoxin deoxynivalenol (DON) is known to affect intestinal functions. However, its effect on intestinal mucus is poorly characterized. METHODS AND RESULTS: We analyzed the effects of DON on human goblet cells (HT29-16E cells) and porcine intestinal explants. Results showed that subtoxic doses of DON (as low as 1 µM) decreased mucin (MUC) production. qPCR analysis demonstrated that this inhibition was due to a specific decrease in the level of mRNA encoding for the intestinal membrane-associated (MUC1) and the secreted MUCs (MUC2, MUC3). Mechanistic studies demonstrated that DON effect relied on the activation of the protein kinase R and the mitogen-activated protein kinase p38 ultimately leading to the inhibition of the expression of resistin-like molecule beta, a known positive regulator of MUC expression. CONCLUSION: Taken together, our results show that at low doses found in food and feed, DON is able to affect the expression and production of MUCs by human and animal goblet cells. Due to the important role of MUCs in the barrier function and in the interaction of commensal bacteria with the host, such effect could explain the observed modifications in the microbial diversity and the increased susceptibility to enteric infection following exposure to DON.


Assuntos
Células Caliciformes/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Tricotecenos/toxicidade , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica , Células HT29 , Humanos , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Intestinos/citologia , Masculino , Mucina-1/genética , Mucina-1/metabolismo , Mucina-2/genética , Mucina-2/metabolismo , Mucina-3/genética , Mucina-3/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Resistina/genética , Resistina/metabolismo , Suínos , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
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