Metastatic effects of hydroxy-polycyclic aromatic hydrocarbons on liver cancer cells mediated by estrogen receptor α.

Hydroxy-polycyclic aromatic hydrocarbons (OH-PAHs) are a growing worldwide concern because of their persistence, ubiquity, and toxicity. Nonetheless, research on the toxicological mechanisms of OH-PAHs remains sparse, particularly concerning the risk of liver cancer. This study evaluated the effects of OH-PAHs on disrupting estrogen receptor α (ERα) and subsequently facilitating hepatocellular invasion and metastasis. Results revealed that all six OH-PAHs exhibited ERα agonistic activities at noncytotoxic levels, which were partially validated using molecular docking (MD) and molecular dynamics simulations (MDS). Furthermore, OH-PAHs with ERα agonistic properties stimulated a concentration-dependent increase in the migration and invasion of HepG2 cells. In addition, they disturbed the expression of target genes associated with epithelial-mesenchymal transition (EMT) and extracellular matrix (ECM), and the invasion effects were significantly reversed by adding an ERα antagonist. Our results suggest an essential role of ERα in the metastasis of liver cancer cells induced by OH-PAHs and emphasize their potential ecological and health hazards.

Characterization and efficacy against carbapenem-resistant Acinetobacter baumannii of a novel Friunavirus phage from sewage.

Carbapenem-resistant Acinetobacter baumannii (CRAB) has become a new threat in recent years, owing to its rapidly increasing resistance to antibiotics and new effective therapies are needed to combat this pathogen. Phage therapy is considered to be the most promising alternative for treating CRAB infections. In this study, a novel phage, Ab_WF01, which can lyse clinical CRAB, was isolated and characterized from hospital sewage. The multiplicity of infection, morphology, one-step growth curve, stability, sensitivity, and lytic activity of the phage were also investigated. The genome of phage Ab_WF01 was 41, 317 bp in size with a GC content of 39.12% and encoded 51 open reading frames (ORFs). tRNA, virulence, and antibiotic resistance genes were not detected in the phage genome. Comparative genomic and phylogenetic analyses suggest that phage Ab_WF01 is a novel species of the genus Friunavirus, subfamily Beijerinckvirinae, and family Autographiviridae. The in vivo results showed that phage Ab_WF01 significantly increased the survival rate of CRAB-infected Galleria mellonella (from 0% to 70% at 48 h) and mice (from 0% to 60% for 7 days). Moreover, after day 3 post-infection, phage Ab_WF01 reduced inflammatory response, with strongly ameliorated histological damage and bacterial clearance in infected tissue organs (lungs, liver, and spleen) in mouse CRAB infection model. Taken together, these results show that phage Ab_WF01 holds great promise as a potential alternative agent with excellent stability for against CRAB infections.

The role of transcriptional regulators in metal ion homeostasis of Mycobacterium tuberculosis.

Metal ions are essential trace elements for all living organisms and play critical catalytic, structural, and allosteric roles in many enzymes and transcription factors. Mycobacterium tuberculosis (MTB), as an intracellular pathogen, is usually found in host macrophages, where the bacterium can survive and replicate. One of the reasons why Tuberculosis (TB) is so difficult to eradicate is the continuous adaptation of its pathogen. It is capable of adapting to a wide range of harsh environmental stresses, including metal ion toxicity in the host macrophages. Altering the concentration of metal ions is the common host strategy to limit MTB replication and persistence. This review mainly focuses on transcriptional regulatory proteins in MTB that are involved in the regulation of metal ions such as iron, copper and zinc. The aim is to offer novel insights and strategies for screening targets for TB treatment, as well as for the development and design of new therapeutic interventions.

Roles of Lipolytic enzymes in Mycobacterium tuberculosis pathogenesis.

Mycobacterium tuberculosis (Mtb) is a bacterial pathogen that can endure for long periods in an infected patient, without causing disease. There are a number of virulence factors that increase its ability to invade the host. One of these factors is lipolytic enzymes, which play an important role in the pathogenic mechanism of Mtb. Bacterial lipolytic enzymes hydrolyze lipids in host cells, thereby releasing free fatty acids that are used as energy sources and building blocks for the synthesis of cell envelopes, in addition to regulating host immune responses. This review summarizes the relevant recent studies that used in vitro and in vivo models of infection, with particular emphasis on the virulence profile of lipolytic enzymes in Mtb. A better understanding of these enzymes will aid the development of new treatment strategies for TB. The recent work done that explored mycobacterial lipolytic enzymes and their involvement in virulence and pathogenicity was highlighted in this study. Lipolytic enzymes are expected to control Mtb and other intracellular pathogenic bacteria by targeting lipid metabolism. They are also potential candidates for the development of novel therapeutic agents.

Mycobacteriophages in diagnosis and alternative treatment of mycobacterial infections.

Antimicrobial resistance is an increasing threat to human populations. The emergence of multidrug-resistant "superbugs" in mycobacterial infections has further complicated the processes of curing patients, thereby resulting in high morbidity and mortality. Early diagnosis and alternative treatment are important for improving the success and cure rates associated with mycobacterial infections and the use of mycobacteriophages is a potentially good option. Since each bacteriophage has its own host range, mycobacteriophages have the capacity to detect specific mycobacterial isolates. The bacteriolysis properties of mycobacteriophages make them more attractive when it comes to treating infectious diseases. In fact, they have been clinically applied in Eastern Europe for several decades. Therefore, mycobacteriophages can also treat mycobacteria infections. This review explores the potential clinical applications of mycobacteriophages, including phage-based diagnosis and phage therapy in mycobacterial infections. Furthermore, this review summarizes the current difficulties in phage therapy, providing insights into new treatment strategies against drug-resistant mycobacteria.

Influence of optical surface distortion in a cylindrical Offner stretcher on the far-field signal-to-noise ratio.

In a stretcher, the surface distortion of the optical elements can introduce spectral phase modulations into the laser, which can affect the laser's signal-to-noise ratio. In this paper, by combining ray tracing methods and angular spectrum diffraction methods, the impact of the mid-frequency surface distortion of the optical elements in an cylindrical Offner stretcher on the far-field signal-to-noise ratio of the laser is simulated. The results show that reducing the spatial chirp on the convex cylindrical mirror can effectively improve the far-field signal-to-noise ratio of the laser, and two methods to improve the far-field signal-to-noise ratio are presented.

Enhancing TB Vaccine Efficacy: Current Progress on Vaccines, Adjuvants and Immunization Strategies.

Tuberculosis (TB) remains a global infectious disease primarily transmitted via respiratory tract infection. Presently, vaccination stands as the primary method for TB prevention, predominantly reliant on the Bacillus Calmette-Guérin (BCG) vaccine. Although it is effective in preventing disseminated diseases in children, its impact on adults is limited. To broaden vaccine protection, efforts are underway to accelerate the development of new TB vaccines. However, challenges arise due to the limited immunogenicity and safety of these vaccines, necessitating adjuvants to bolster their ability to elicit a robust immune response for improved and safer immunization. These adjuvants function by augmenting cellular and humoral immunity against M. tuberculosis antigens via different delivery systems, ultimately enhancing vaccine efficacy. Therefore, this paper reviews and summarizes the current research progress on M. tuberculosis vaccines and their associated adjuvants, aiming to provide a valuable reference for the development of novel TB vaccines and the screening of adjuvants.

Ultrastretchable, Self-Healable, and Tissue-Adhesive Hydrogel Dressings Involving Nanoscale Tannic Acid/Ferric Ion Complexes for Combating Bacterial Infection and Promoting Wound Healing.

Preventing bacterial infections and accelerating wound closure are essential in the process of wound healing. Current wound dressings lack enough mechanical properties, self-healing ability, and tissue adhesiveness, and the bacterial killing also relies on the use of antibiotic drugs. Herein, a well-designed hybrid hydrogel dressing is constructed by simple copolymerization of acrylamide (AM), 3-acrylamido phenylboronic acid (AAPBA), chitosan (CS), and the nanoscale tannic acid (TA)/ferric ion (Fe3+) complex (TFe). The resulting hydrogel possesses lots of free catechol, phenylboronic acid, amine, and hydroxyl groups and contains many reversible and dynamic bonds such as multiple hydrogen bonds and boronate ester bonds, thereby showing satisfactory mechanical properties, fast self-healing ability, and desirable tissue-adhesive performance. Benefiting from the high photothermal conversion efficiency of the TFe, the hydrogel exhibits satisfactory antibacterial activity against both Gram-positive and Gram-negative bacteria. Moreover, the embedded TFe also endows the hydrogel with good antioxidant activity, anti-inflammatory property, and cell proliferation to promote tissue regeneration. Remarkably, in vivo animal assays reveal that the hybrid hydrogel effectively eliminates biofilm bacteria in the wound sites and accelerates the healing process of infected wounds. Taken together, the developed versatile hydrogels overcome the shortcomings of traditional wound dressings and are expected to become potential antibacterial dressings for future biomedical applications.

Rapid In Situ Deposition of Iron-Chelated Polydopamine Coating on the Polyacrylamide Hydrogel Dressings for Combined Photothermal and Chemodynamic Therapy of Skin Wound Infection.

Pathogenic bacterial infections of skin wounds have caused a significant threat to clinical treatment and human life safety. Here, we develop a bactericidal hydrogel dressing consisting of a polyacrylamide (PAM) hydrogel framework with in situ surface-deposition of iron-dopped polydopamine (FePDA). The prepared hydrogel dressing (FePDA-PAM) has a compact surface, good tensile strength, and excellent elastic recovery ability. The introduction of Fe3+ ions improve the photothermal therapy (PTT) efficiency of the PDA and endow the hydrogel dressing with chemodynamic therapy (CDT) properties. In vitro experiments show that the antibacterial effect of FePDA-PAM hydrogel on Staphylococcus aureus reach nearly 100% under the combined action of H2O2 and 808 nm near-infrared (NIR) laser, indicating an excellent combined antibacterial property of PTT and CDT. Furthermore, the FePDA-PAM + H2O2 + NIR treatment group in the in vivo antibacterial experiments displays lowest relative wound area and optimal wound healing within 5 days of treatment, thereby indicating the intensive skin wound disinfection. To summarize, the FePDA-PAM hydrogel has simple preparation and good biosafety. It may serve as a potential wound dressing for the combined PTT/CDT dual-mode antibacterial therapy.

Plasmid parB contributes to uropathogenic Escherichia coli colonization in vivo by acting on biofilm formation and global gene regulation.

The endogenous plasmid pUTI89 harbored by the uropathogenic Escherichia coli (UPEC) strain UTI89 plays an important role in the acute stage of infection. The partitioning gene parB is important for stable inheritance of pUTI89. However, the function of partitioning genes located on the plasmid in pathogenesis of UPEC still needs to be further investigated. In the present study, we observed that disruption of the parB gene leads to a deficiency in biofilm formation in vitro. Moreover, in a mixed infection with the wild type strain and the parB mutant, in an ascending UTI mouse model, the mutant displayed a lower bacterial burden in the bladder and kidneys, not only at the acute infection stage but also extending to 72 hours post infection. However, in the single infection test, the reduced colonization ability of the parB mutant was only observed at six hpi in the bladder, but not in the kidneys. The colonization capacity in vivo of the parB-complemented strain was recovered. qRT-PCR assay suggested that ParB could be a global regulator, influencing the expression of genes located on both the endogenous plasmid and chromosome, while the gene parA or the operon parAB could not. Our study demonstrates that parB contributes to the virulence of UPEC by influencing biofilm formation and proposes that the parB gene of the endogenous plasmid could regulate gene expression globally.

The prominent alteration in transcriptome and metabolome of Mycobacterium bovis BCG str. Tokyo 172 induced by vitamin B1.

BACKGROUND: Vitamin B1 (VB1) is a crucial dietary nutrient and essential cofactor for several key enzymes in the regulation of cellular and metabolic processes, and more importantly in the activation of immune system. To date, the precise role of VB1 in Mycobacterium tuberculosis remains to be fully understood. RESULTS: In this study, the transcriptional and metabolic profiles of VB1-treated Mycobacterium. bovis BCG were analyzed by RNA-sequencing and LC-MS (Liquid chromatography coupled to mass spectrometry). The selection of BCG strain was based on its common physiological features shared with M. tuberculosis. The results of cell growth assays demonstrated that VB1 inhibited the BCG growth rate in vitro. Transcriptomic analysis revealed that the expression levels of genes related to fatty acid metabolism, cholesterol metabolism, glycolipid catabolism, DNA replication, protein translation, cell division and cell wall formation were significantly downregulated in M. bovis BCG treated with VB1. In addition, the metabolomics LC-MS data indicated that most of the amino acids and adenosine diphosphate (ADP) were decreased in M. bovis BCG strain after VB1 treatment. CONCLUSIONS: This study provides the molecular and metabolic bases to understand the impacts of VB1 on M.bovis BCG.

HIP1R targets PD-L1 to lysosomal degradation to alter T cell-mediated cytotoxicity.

Expression of programmed cell death 1 (PD-1) ligand 1 (PD-L1) protects tumor cells from T cell-mediated immune surveillance, and immune checkpoint blockade (ICB) therapies targeting PD-1 and PD-L1 have exhibited significant clinical benefits. However, the relatively low response rate and observed ICB resistance highlight the need to understand the molecular regulation of PD-L1. Here we show that HIP1R targets PD-L1 to lysosomal degradation to alter T cell-mediated cytotoxicity. HIP1R physically interacts with PD-L1 and delivers PD-L1 to the lysosome through a lysosomal targeting signal. Depletion of HIP1R in tumor cells caused PD-L1 accumulation and suppressed T cell-mediated cytotoxicity. A rationally designed peptide (PD-LYSO) incorporating the lysosome-sorting signal and the PD-L1-binding sequence of HIP1R successfully depleted PD-L1 expression in tumor cells. Our results identify the molecular machineries governing the lysosomal degradation of PD-L1 and exemplify the development of a chimeric peptide for targeted degradation of PD-L1 as a crucial anticancer target.

A novel small RNA Bmsr1 enhances virulence in Brucella melitensis M28.

Brucellosis, caused by Brucella spp., is one of the most serious zoonotic bacterial diseases. Small RNAs (sRNAs) are recognized as a key player in bacterial post-transcription regulation, since they participate in many biological processes with high efficiency and may govern the intracellular biochemistry and virulence of some pathogenic bacteria. Here, a novel small regulatory RNA, Bmsr1 (Brucella melitensis M28 small RNA 1), was identified in a virulent Brucella melitensis M28 strain based on bioinformatic analysis, reverse transcription PCR (RT-PCR), and Northern blot. The Bmsr1 expression level was highly induced after infection of macrophage cells RAW264.7 at 48 h, suggesting a role for Bmsr1 during in vitro infection. Indeed, bmsr1 deletion mutant of M28 attenuated its intracellular survival in RAW264.7 at 24 h and 48 h post-infection. In a mouse model of chronic infection, bmsr1 deletion strain displayed decreased colonization in the spleen while Bmsr1-overexpressed strain showed higher colonization levels than wild type pathogen. Isobaric tags for relative and absolute quantification (iTRAQ) revealed that 314 proteins were differentially expressed in M28Δbmsr1 compared with wild type. Functional annotation analysis demonstrated that most of those proteins are involved in biological processes and those proteins in the ribosome and nitrogen metabolism pathways were enriched. iTRAQ results combined with target prediction identified several potential target genes related to virulence, including virB2, virB9, virB10, virB11, and vjbR and many metabolism genes. Taken together, this study revealed the contribution of a novel sRNA Bmsr1 to virulence of B. melitensis M28, probably by influencing genes involved in T4SS, virulence regulator VjbR and other metabolism genes.

A Designed Peptide Targets Two Types of Modifications of p53 with Anti-cancer Activity.

Many cancer-related proteins are controlled by composite post-translational modifications (PTMs), but prevalent strategies only target one type of modification. Here we describe a designed peptide that controls two types of modifications of the p53 tumor suppressor, based on the discovery of a protein complex that suppresses p53 (suppresome). We found that Morn3, a cancer-testis antigen, recruits different PTM enzymes, such as sirtuin deacetylase and ubiquitin ligase, to confer composite modifications on p53. The molecular functions of Morn3 were validated through in vivo assays and chemico-biological intervention. A rationally designed Morn3-targeting peptide (Morncide) successfully activated p53 and suppressed tumor growth. These findings shed light on the regulation of protein PTMs and present a strategy for targeting two modifications with one molecule.

Complete Genome Sequences of Two Porcine Enterotoxigenic Escherichia coli Strains.

Enterotoxigenic Escherichia coli (ETEC) is one of the main causes of illness and death in neonatal and recently weaned pigs. Here, we sequenced the genomes of two ETEC strains that were previously used as inactivated vaccines in China.

Competition between bacteria and phosphate for adsorption sites on gibbsite: An in-situ ATR-FTIR spectroscopic and macroscopic study.

Sorption and desorption of phosphate (P) on Fe and Al (hydr)oxides may be affected by bacteria in soils because their ubiquitous and strong interactions. The role of Bacillus subtilis and Pseudomonas fluorescens in adsorption of P on gibbsite (γ-AlOOH) was systematically investigated under a wide range of conditions by combining in-situ attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy with batch macroscopic experiments. In-situ ATR-FTIR observations of the ternary systems (bacteria, P, and gibbsite) showed simultaneous desorption of P from, and adhesion of the bacteria to, gibbsite, indicating a competition between the two for surface sites. Batch desorption experiments showed that bacteria could mobilize the P from gibbsite into solution, and macroscopic adsorption data showed that the amount of P adsorbed on the bacteria-gibbsite complex was less than that on gibbsite alone over durations from 0h to 26h, concentrations of P from 0.1mM to 2.0mM, pH from 5 to 8, and ionic strength from 0M to 0.5M, suggesting that bacteria inhibit the adsorption of P on gibbsite. The degree of inhibition increased with the number of bacteria in the system and was significantly but non-linearly correlated with the decline in the positive charge on gibbsite induced by the bacteria. Therefore, competition for suitable sites on the surface of gibbsite between P and the bacteria and reduction in the positive charge on the surface of gibbsite induced by bacteria are proposed as two important mechanisms that inhibit P adsorption. These findings highlight the role of bacteria in regulating the availability of P to plants and its mobility in natural environments.

New Targets and Cofactors for the Transcription Factor LrpA from Mycobacterium tuberculosis.

Rv3291c (MtbLrpA), a transcriptional regulator, belongs to the leucine-responsive regulatory protein (Lrp) family and is thought to play an important role in Mycobacterium tuberculosis persistence. In this study, we verified 17 novel potential binding sites for MtbLrpA by in vitro binding assays on the basis of previous predictions from an in silico analysis and bacterial one-hybrid (BIH) reporter system. Amino acids, such as tyrosine, phenylalanine, tryptophan, and histidine, strongly affect the binding affinity of MtbLrpA, and vitamins, including B1, B3, B6, VC, B7, B9, B12, VA, and VK3, also decrease MtbLrpA binding affinity. This is the first report regarding that an Lrp-like protein can sense vitamins as an environmental signal. Vitamin supplementation to the environment can change the expression level of the target genes, which provides a potential mechanism for tuberculosis supplementary treatment with vitamins.

Characteristics of invasion-reduced hilA gene mutant of Salmonella Enteritidis in vitro and in vivo.

Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) is a facultative intracellular pathogen that causes huge losses in poultry industry and also food poisoning in humans due to its being a food-borne pathogen. Functions of Invasion-related genes need to be explored, as invasion is a key step for Salmonella infection. In this study, a transposon mutant library of Salmonella Enteritidis isolate SM6 was constructed and screened for the invasion-related genes via incubation with Caco-2 cells. Three stably attenuated mutants were identified for significantly reduced invasion with insertions all in hilA (hyperinvasive locus A) gene. We constructed and evaluated the hilA deletion mutant in vivo and in vitro. SM6△hilA showed significantly reduced ability to invade Caco-2 cells and decreased pathogenicity in chicks. However, the bacterial load and pathological damage in the cecum were significantly higher than those in the SM6 in vivo. Present results provide new evidences for pathogenicity research on Salmonella Enteritidis.

Aquatic risk assessment of a novel strobilurin fungicide: A microcosm study compared with the species sensitivity distribution approach.

The ecotoxicological effects of pyraoxystrobin, a novel strobilurin fungicide, were studied using outdoor freshwater microcosms and the species sensitivity distribution approach. The microcosms were treated with pyraoxystrobin at concentrations of 0, 1.0, 3.0, 10, 30 and 100µg/L. Species sensitivity distribution (SSD) curves were constructed by means of acute toxicity data using the BurrliOZ model for fourteen representatives of sensitive invertebrates, algae and fish and eleven taxa of invertebrates and algae, respectively. The responses of zooplankton, phytoplankton and physical and chemical endpoints in microcosms were studied. Zooplankton, especially Sinodiaptomus sarsi was the most sensitive to pyraoxystrobin exposure in the microcosms. Short-term toxic effects (<8 weeks) on zooplankton occurred in 1µg/L treatment group. The duration of toxic effects on S. sarsi could not be evaluated within the initial 56 days. Significant long-term toxic effects were observed at 10, 30 and 100µg/L (>281 days) for S. sarsi and the zooplankton community. Based on the results obtained from the organisms in the microcosm system, 1µg/L was recommended as the NOEAEC (no observed ecologically adverse effect concentration). Also, 0.33µg/L was derived as the Regulatory Acceptable Concentration based on the ecological recovery option (ERO-RAC) of pyraoxystrobin. For all fourteen tested species, the median HC5 (hazardous concentration affecting 5% of species) was 0.86µg/L, and the lower limit HC5 (LL-HC5) was 0.39µg/L. For the eleven taxa of invertebrates and algae tested, the median HC5 was 1.1µg/L, and the LL-HC5 was 0.26µg/L. The present study positively contributes to the suggestion of adequately using acute L(E)C50-based HC5/ LL-HC5 for deriving protective concentrations for strobilurin fungicides, and it should be valuable for full comprehension of the potential toxicity of pyraoxystrobin in aquatic ecosystems.

Curing a large endogenous plasmid by single substitution of a partitioning gene.

To investigate whether plasmid-free cells of pathogenic Escherichia coli can be isolated by disrupting a single gene in an endogenous plasmid without further treatment, the effect of the disruption of partitioning genes on the inheritance of the endogenous plasmid pUTI89 of the uropathogenic E. coli strain UTI89 was studied. We found that mutation of parB, which encodes a type Ib partitioning protein, could cause loss of the endogenous plasmid at a ratio of about 1%. Clones derived from parB mutants, identified by antibiotic sensitivity, were all plasmid free. Plasmid instability caused by the parB mutation was found to correlate with a negative effect on host cell growth. Thus, in this pathogenic E. coli, an endogenous plasmid as large as 114 kbp could be cured effectively by targeting a single type Ib partitioning gene followed by passaging, which may facilitate further investigations on the function of endogenous plasmids in their natural hosts.