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Journal of Advanced Research Oct 2023The perturbations of gut microbiota could interact with excessively activated immune responses and play key roles in the etiopathogenesis of ulcerative colitis (UC)....
INTRODUCTION
The perturbations of gut microbiota could interact with excessively activated immune responses and play key roles in the etiopathogenesis of ulcerative colitis (UC). Desulfovibrio, the most predominant sulfate reducing bacteria (SRB) resided in the human gut, was observed to overgrow in patients with UC. The interactions between specific gut microbiota and drugs and their impacts on UC treatment have not been demonstrated well.
OBJECTIVES
This study aimed to elucidate whether Desulfovibrio vulgaris (D. vulgaris, DSV) and its flagellin could activate nucleotide-binding oligomerization domain-like receptors (NLR) family of apoptosis inhibitory proteins (NAIP) / NLR family caspase activation and recruitment domain-containing protein 4 (NLRC4) inflammasome and promote colitis, and further evaluate the efficacy of eugeniin targeting the interaction interface of D. vulgaris flagellin (DVF) and NAIP to attenuate UC.
METHODS
The abundance of DSV and the occurrence of macrophage pyroptosis in human UC tissues were investigated. Colitis in mice was established by dextran sulfate sodium (DSS) and gavaged with DSV or its purified flagellin. NAIP/NLRC4 inflammasome activation and macrophage pyroptosis were evaluated in vivo and in vitro. The effects of eugeniin on blocking the interaction of DVF and NAIP/NLRC4 and relieving colitis were also assessed.
RESULTS
The abundance of DSV increased in the feces of patients with UC and was found to be associated with disease activity. DSV and its flagellin facilitated DSS-induced colitis in mice. Mechanistically, RNA sequencing showed that gene expression associated with inflammasome complex and pyroptosis was upregulated after DVF treatment in macrophages. DVF was further demonstrated to induce significant macrophage pyroptosis in vitro, depending on NAIP/NLRC4 inflammasome activation. Furthermore, eugeniin was screened as an inhibitor of the interface between DVF and NAIP and successfully alleviated the proinflammatory effect of DVF in colitis.
CONCLUSION
Targeting DVF-induced NAIP/NLRC4 inflammasome activation and macrophage pyroptosis ameliorates UC. This finding is of great significance for exploring the gut microbiota-host interactions in UC development and providing new insights for precise treatment.
Topics: Humans; Mice; Animals; Inflammasomes; Flagellin; Desulfovibrio vulgaris; Colitis, Ulcerative; Macrophages; Calcium-Binding Proteins; CARD Signaling Adaptor Proteins; Neuronal Apoptosis-Inhibitory Protein
PubMed: 37586642
DOI: 10.1016/j.jare.2023.08.008 -
Frontiers in Immunology 2023Several existing studies have revealed that the occurrence of lichen planus (LP) is relevant to the gut microbiota, and the causal relationship between gut microbiota...
PURPOSE
Several existing studies have revealed that the occurrence of lichen planus (LP) is relevant to the gut microbiota, and the causal relationship between gut microbiota and LP was analyzed using the Mendelian randomization (MR) method.
METHODS
Through the two-sample MR method, single nucleotide polymorphisms (SNPs) relevant to gut microbiota were selected as instrument variables (IVs) to evaluate the causal association between gut microbiota and the risk of LP.
RESULTS
According to the selection criteria of inverse-variance weighted (IVW), six bacterial genera were found to be significantly linked to the initiation of LP; The IVW results suggested that Oxalobacteraceae, Victivallaceae, and Actinobacteria could restrain the initiation of LP, showing protective effects against LP. Desulfovibrio, Veillonella, and Ruminococcus gauvreauii groups were demonstrated to have casual correlations with the onset of LP.
CONCLUSION
The relationship between gut microbiota and LP was not a single positive or inverse relationship. Investigation of the causal relationship of these gut microbiota with LP could further provide evidence for the intestine-skin axis theory. However, the specific mechanism of microorganisms affecting the skin remains to be clarified. In this paper, the protective effects and mechanisms of Oxalobacteraceae, Victivallaceae, and Actinobacteria on LP require further exploration.
PubMed: 37767099
DOI: 10.3389/fimmu.2023.1235982 -
Accounts of Chemical Research Nov 2015The development of technology for the inexpensive generation of the renewable energy vector H2 through water splitting is of immediate economic, ecological, and...
The development of technology for the inexpensive generation of the renewable energy vector H2 through water splitting is of immediate economic, ecological, and humanitarian interest. Recent interest in hydrogenases has been fueled by their exceptionally high catalytic rates for H2 production at a marginal overpotential, which is presently only matched by the nonscalable noble metal platinum. The mechanistic understanding of hydrogenase function guides the design of synthetic catalysts, and selection of a suitable hydrogenase enables direct applications in electro- and photocatalysis. [FeFe]-hydrogenases display excellent H2 evolution activity, but they are irreversibly damaged upon exposure to O2, which currently prevents their use in full water splitting systems. O2-tolerant [NiFe]-hydrogenases are known, but they are typically strongly biased toward H2 oxidation, while H2 production by [NiFe]-hydrogenases is often product (H2) inhibited. [NiFeSe]-hydrogenases are a subclass of [NiFe]-hydrogenases with a selenocysteine residue coordinated to the active site nickel center in place of a cysteine. They exhibit a combination of unique properties that are highly advantageous for applications in water splitting compared with other hydrogenases. They display a high H2 evolution rate with marginal inhibition by H2 and tolerance to O2. [NiFeSe]-hydrogenases are therefore one of the most active molecular H2 evolution catalysts applicable in water splitting. Herein, we summarize our recent progress in exploring the unique chemistry of [NiFeSe]-hydrogenases through biomimetic model chemistry and the chemistry with [NiFeSe]-hydrogenases in semiartificial photosynthetic systems. We gain perspective from the structural, spectroscopic, and electrochemical properties of the [NiFeSe]-hydrogenases and compare them with the chemistry of synthetic models of this hydrogenase active site. Our synthetic models give insight into the effects on the electronic properties and reactivity of the active site upon the introduction of selenium. We have utilized the exceptional properties of the [NiFeSe]-hydrogenase from Desulfomicrobium baculatum in a number of photocatalytic H2 production schemes, which are benchmark systems in terms of single site activity, tolerance toward O2, and in vitro water splitting with biological molecules. Each system comprises a light-harvesting component, which allows for light-driven electron transfer to the hydrogenase in order for it to catalyze H2 production. A system with [NiFeSe]-hydrogenase on a dye-sensitized TiO2 nanoparticle gives an enzyme-semiconductor hybrid for visible light-driven generation of H2 with an enzyme-based turnover frequency of 50 s(-1). A stable and inexpensive polymeric carbon nitride as a photosensitizer in combination with the [NiFeSe]-hydrogenase shows good activity for more than 2 days. Light-driven H2 evolution with the enzyme and an organic dye under high O2 levels demonstrates the excellent robustness and feasibility of water splitting with a hydrogenase-based scheme. This has led, most recently, to the development of a light-driven full water splitting system with a [NiFeSe]-hydrogenase wired to the water oxidation enzyme photosystem II in a photoelectrochemical cell. In contrast to the other systems, this photoelectrochemical system does not rely on a sacrificial electron donor and allowed us to establish the long sought after light-driven water splitting with an isolated hydrogenase.
Topics: Biomimetic Materials; Deltaproteobacteria; Desulfovibrio vulgaris; Hydrogenase; Photosynthesis; Selenocysteine
PubMed: 26488197
DOI: 10.1021/acs.accounts.5b00326 -
Microorganisms Jul 2023(DSV) are sulfate-reducing bacteria (SRB) that are ubiquitously present in the environment and as resident commensal bacteria within the human gastrointestinal tract.... (Review)
Review
(DSV) are sulfate-reducing bacteria (SRB) that are ubiquitously present in the environment and as resident commensal bacteria within the human gastrointestinal tract. Though they are minor residents of the healthy gut, DSV are opportunistic pathobionts that may overgrow in the setting of various intestinal and extra-intestinal diseases. An increasing number of studies have demonstrated a positive correlation between DSV overgrowth (bloom) and various human diseases. While the relationship between DSV bloom and disease pathology has not been clearly established, mounting evidence suggests a causal role for these bacteria in disease development. As DSV are the most predominant genera of SRB in the gut, this review summarizes current knowledge regarding the relationship between DSV and a variety of diseases. In this study, we also discuss the mechanisms by which these bacteria may contribute to disease pathology.
PubMed: 37512944
DOI: 10.3390/microorganisms11071772 -
CNS Neuroscience & Therapeutics Nov 2022There might be more than 10 million confirmed cases of Parkinson's disease (PD) worldwide by 2040. However, the pathogenesis of PD is still unclear. Host health is... (Review)
Review
There might be more than 10 million confirmed cases of Parkinson's disease (PD) worldwide by 2040. However, the pathogenesis of PD is still unclear. Host health is closely related to gut microbiota, which are affected by factors such as age, diet, and exercise. Recent studies have found that gut microbiota may play key roles in the progression of a wide range of diseases, including PD. Changes in the abundance of gut bacteria, such as Helicobacter pylori, Enterococcus faecalis, and Desulfovibrio, might be involved in PD pathogenesis or interfere with PD therapy. Gut microbiota and the distal brain achieve action on each other through a gut-brain axis composed of the nervous system, endocrine system, and immune system. Here, this review focused on the current understanding of the connection between Parkinson's disease and gut microbiota, to provide potential therapeutic targets for PD.
Topics: Brain; Gastrointestinal Microbiome; Humans; Parkinson Disease
PubMed: 35822696
DOI: 10.1111/cns.13916 -
Nature Reviews. Microbiology Dec 2021The defining trait of obligate anaerobes is that oxygen blocks their growth, yet the underlying mechanisms are unclear. A popular hypothesis was that these... (Review)
Review
The defining trait of obligate anaerobes is that oxygen blocks their growth, yet the underlying mechanisms are unclear. A popular hypothesis was that these microorganisms failed to evolve defences to protect themselves from reactive oxygen species (ROS) such as superoxide and hydrogen peroxide, and that this failure is what prevents their expansion to oxic habitats. However, studies reveal that anaerobes actually wield most of the same defences that aerobes possess, and many of them have the capacity to tolerate substantial levels of oxygen. Therefore, to understand the structures and real-world dynamics of microbial communities, investigators have examined how anaerobes such as Bacteroides, Desulfovibrio, Pyrococcus and Clostridium spp. struggle and cope with oxygen. The hypoxic environments in which these organisms dwell - including the mammalian gut, sulfur vents and deep sediments - experience episodic oxygenation. In this Review, we explore the molecular mechanisms by which oxygen impairs anaerobes and the degree to which bacteria protect their metabolic pathways from it. The emergent view of anaerobiosis is that optimal strategies of anaerobic metabolism depend upon radical chemistry and low-potential metal centres. Such catalytic sites are intrinsically vulnerable to direct poisoning by molecular oxygen and ROS. Observations suggest that anaerobes have evolved tactics that either minimize the extent to which oxygen disrupts their metabolism or restore function shortly after the stress has dissipated.
Topics: Anaerobiosis; Bacteria, Anaerobic; Bacteroides; Clostridium; Desulfovibrio; Hydrogen Peroxide; Oxygen; Pyrococcus; Reactive Oxygen Species; Superoxides
PubMed: 34183820
DOI: 10.1038/s41579-021-00583-y -
Microorganisms Jan 2023belongs to Sulfate-reducing bacteria (SRB), which are widely present in anaerobic environments, including the human gut. has been associated with many human diseases,...
belongs to Sulfate-reducing bacteria (SRB), which are widely present in anaerobic environments, including the human gut. has been associated with many human diseases, including chronic liver disease. However, the characteristics and difference of from fecal samples of healthy volunteers (HV) and patients with liver cirrhosis (LC) have not been fully elucidated. Here, we isolated from the feces of 6 HV and 9 LC, and 88 strains were obtained. In the feces of HV, 55% of isolated strains were , followed by (15%), D. (11%), (9%), (4%), (4%) and (2%). However, only (60%) and (40%) were isolated from fecal samples of patients with LC. Our results suggest that there was a significant difference in the desulfurization ability and the HS production ability of different . . Furthermore, we found that isolated from the patients with LC generally had a higher hydrogen sulfide production capacity, gastrointestinal tolerance, and levels of antibiotic resistance than the same species isolated from HV. Our findings suggested that may be associated with the occurrence and development of liver cirrhosis.
PubMed: 36838242
DOI: 10.3390/microorganisms11020276 -
Gut Microbes 2022Gastrointestinal dysfunction is a common symptom of acute mountain sickness (AMS). The gut microbiota and γδ T cells play critical roles in intestinal disease....
Gastrointestinal dysfunction is a common symptom of acute mountain sickness (AMS). The gut microbiota and γδ T cells play critical roles in intestinal disease. However, the mechanistic link between the microbiota and γδ T cells in hypoxia-induced intestinal injury remains unclear. Here, we show that hypoxia-induced intestinal damage was significantly alleviated after microbiota depletion with antibiotics. Hypoxia modulated gut microbiota composition by promoting antimicrobial peptides angiogenin-4 secretions. The abundance of in the gut of mice after hypoxia significantly decreased, while the abundance of significantly increased. Furthermore, -derived phosphatidylethanolamine and phosphatidylcholine promoted γδ T cell activation. In CD1d-deficient mice, the levels of intraepithelial IL-17A and γδ T cells and intestinal damage were significantly decreased compared with those in wild-type mice under hypoxia. Mechanistically, phospholipid metabolites from are presented by intestinal epithelial CD1d to induce the proliferation of IL-17A-producing γδ T cells, which aggravates intestinal injury. Gut microbiota-derived metabolites promote hypoxia-induced intestinal injury via CD1d-dependent γδ T cells, suggesting that phospholipid metabolites and γδ T cells can be targets for AMS therapy.
Topics: Animals; Gastrointestinal Microbiome; Hypoxia; Interleukin-17; Intestinal Diseases; Mice; Mice, Inbred C57BL; Phospholipids; Receptors, Antigen, T-Cell, gamma-delta; T-Lymphocytes
PubMed: 35898110
DOI: 10.1080/19490976.2022.2096994 -
Arthritis & Rheumatology (Hoboken, N.J.) Sep 2021Systemic inflammatory factors have been implicated in symptomatic hand osteoarthritis (OA). Gut microbiome dysbiosis promotes systemic inflammation. The aim of this...
OBJECTIVE
Systemic inflammatory factors have been implicated in symptomatic hand osteoarthritis (OA). Gut microbiome dysbiosis promotes systemic inflammation. The aim of this study was to examine the association between the gut microbiome and the presence of symptomatic hand OA in a population-based study.
METHODS
Study participants were subjects of the Xiangya Osteoarthritis Study, a community-based observational study conducted in the Hunan Province of China. Symptomatic hand OA was defined as the presence of both symptoms and radiographic OA in the same hand. The gut microbiome was analyzed using 16S ribosomal RNA gene sequencing in stool samples. We examined the relation of α-diversity, β-diversity, relative abundance of taxa, and potential bacterial functional pathways to symptomatic hand OA.
RESULTS
A total of 1,388 participants (mean age 61.3 years, 57.4% women) were included in the study, of whom 72 had symptomatic hand OA (prevalence of symptomatic hand OA 5.2%). Beta-diversity of the gut microbiome, but not α-diversity, was significantly associated with the presence of symptomatic hand OA (P = 0.003). Higher relative abundance of the genera Bilophila and Desulfovibrio as well as lower relative abundance of the genus Roseburia was associated with symptomatic hand OA. Most functional pathways (i.e., those annotated in the KEGG Ortholog hierarchy) that were observed to be altered in participants with symptomatic hand OA belonged to the amino acid, carbohydrate, and lipid metabolic pathways.
CONCLUSION
This large, population-based study provides the first evidence that alterations in the composition of the gut microbiome were observed among study participants who had symptomatic hand OA, and a low relative abundance of Roseburia but high relative abundance of Bilophila and Desulfovibrio at the genus level were associated with prevalent symptomatic hand OA. These findings may help investigators understand the role of the microbiome in the development of symptomatic hand OA and could contribute to potential translational opportunities.
Topics: Adult; Aged; Feces; Female; Gastrointestinal Microbiome; Hand Joints; Humans; Male; Middle Aged; Osteoarthritis; RNA, Ribosomal, 16S
PubMed: 33760399
DOI: 10.1002/art.41729 -
Frontiers in Chemistry 2021Nanoscale materials have recently gained wide attention due to their potential to revolutionize many technologies and industrial sectors, including information... (Review)
Review
Nanoscale materials have recently gained wide attention due to their potential to revolutionize many technologies and industrial sectors, including information technology, homeland security, transportation, energy, food safety, environmental science, catalysis, photonics and medicine. Among various nanoparticles, platinum nanoparticles (PtNPs) are widely used for biomedical applications, including imaging, implants, photothermal therapy and drug delivery. Indeed, PtNPs possesses intrinsic antimicrobial, antioxidant, and anticancer properties. Also, due to their remarkable catalytic activity, they are able to reduce the intracellular reactive oxygen species (ROS) levels and impair the downstream pathways leading to inflammation. Various approaches, including both physical and chemical methods, are currently employed for synthesis of PtNPs. However, the use of hazardous reaction conditions and toxic chemicals in these processes poses a potential threat to the environment and severely compromise the biocompatibility of the nanoparticles. Hereby, increasing need for exploitation of novel routes for synthesis of PtNPs has led to development of biological fabrication using microbes, specifically bacteria. Herein, we present a most comprehensive report on biogenesis of PtNPs by several bacteria like , etc. An overview of the underlying mechanisms of both enzymatic and non-enzymatic methods of synthesis is included. Moreover, this review highlights the scope of developing optimized process to control the physicochemical properties, such as the nanoparticle surface chemistry, charge, size and shape, which, in turn, may affect their nanotoxicity and response at the biointerface for nanomedicine applications.
PubMed: 33763405
DOI: 10.3389/fchem.2021.624344