Antibacterial Response Research Articles

NOX-derived ROS modulates the antibacterial immune responses in coelomocytes of Apostichopus japonicus

As an important generator of reactive oxygen species (ROS) in eukaryotic cells, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) is essential to antimicrobial host defense. AjNOX, a member of the NOX family, was identified in Apostichopus japonicus during the current investigation. It encodes a polypeptide with 571 amino acids, and it has an open reading frame of 1716 bp. The inferred amino acid sequence of AjNOX includes a transmembrane domain, a ferric reductase domain, a flavin adenine dinucleotide-binding-8 domain, and a NADPH-binding-6 domain. AjNOX shares 53.03%–42.39% sequence homology with other NOX proteins found in vertebrates and invertebrates in accordance with multiple sequence alignment. AjNOX was found in close proximity to the sea urchin SpNOX and the vertebrate NOX1–3 on the phylogenetic tree. The AjNOX gene was expressed in all of the test tissues including the body wall, muscle, intestine, respiratory tree, and coelomocytes. After being challenged with Vibrio splendidus, sea cucumber coelomocytes showed a remarkable increase in the protein and mRNA levels of AjNOX. ROS was produced less remarkably in coelomocytes as a result of AjNOX RNA interference. When the expression of AjNOX was suppressed by siRNA or inhibitor, the ability of coelomocytes to remove bacteria was drastically decreased. Reducing AjNOX-derived ROS decreased the production of inflammatory cytokines and coelomocyte apoptosis. All of these findings indicate that AjNOX may be crucial to the antibacterial immune response against the invasive pathogen V. splendidus in sea cucumbers A. japonicus.

Modified polymeric biomaterials with antimicrobial and immunomodulating properties

The modification of the surgical polypropylene mesh and the polytetrafluoroethylene vascular prosthesis with cecropin A (small peptide) and puromycin (aminonucleoside) yielded very stable preparations of modified biomaterials. The main emphasis was placed on analyses of their antimicrobial activity and potential immunomodulatory and non-cytotoxic properties towards the CCD841 CoTr model cell line. Cecropin A did not significantly affect the viability or proliferation of the CCD 841 CoTr cells, regardless of its soluble or immobilized form. In contrast, puromycin did not induce a significant decrease in the cell viability or proliferation in the immobilized form but significantly decreased cell viability and proliferation when administered in the soluble form. The covalent immobilization of these two molecules on the surface of biomaterials resulted in stable preparations that were able to inhibit the multiplication of Staphylococcus aureus and S. epidermidis strains. It was also found that the preparations induced the production of cytokines involved in antibacterial protection mechanisms and stimulated the immune response. The key regulator of this activity may be related to TLR4, a receptor recognizing bacterial LPS. In the present study, these factors were produced not only in the conditions of LPS stimulation but also in the absence of LPS, which indicates that cecropin A- and puromycin-modified biomaterials may upregulate pathways leading to humoral antibacterial immune response.

Glycol Chitosan-Poly(lactic acid) Conjugate Nanoparticles Encapsulating Ciprofloxacin: A Mucoadhesive, Antiquorum-Sensing, and Biofilm-Disrupting Treatment Modality for Bacterial Keratitis.

Bacterial keratitis (BK) causes visual morbidity/blindness if not treated effectively. Here, ciprofloxacin (CIP)-loaded nanoparticles (NPs) using glycol chitosan (GC) and poly(lactic acid) (PLA) conjugate at three different ratios (CIP@GC(PLA) NPs (1:1,5,15)) were fabricated. CIP@GC(PLA) NPs (1:1) were more effective than other tested ratios, indicating the importance of optimal hydrophobic/hydrophilic balance for corneal penetration and preventing bacterial invasion. The CIP@GC(PLA) (NPs) (1:1) realized the highest association with human corneal epithelial cells, which were nonirritant to the hen's egg-chorioallantoic membrane test (HET-CAM test) and demonstrated significant antibacterial response in the in vitro minimum inhibitory, bactericidal, live-dead cells, zone of inhibition, and biofilm inhibition assays against the keratitis-inducing pathogen Pseudomonas aeruginosa. The antiquorum sensing activity of GC has been explored for the first time. The NPs disrupted the bacterial quorum sensing by inhibiting the production of virulence factors, including acyl homoserine lactones, pyocyanin, and motility, and caused significant downregulation of quorum sensing associated genes. In the in vivo studies, CIP@GC(PLA) NPs (1:1) displayed ocular retention in vivo (∼6 h) and decreased the opacity and the bacterial load effectively. Overall, the CIP@GC(PLA) NP (1:1) is a biofilm-disrupting antiquorum sensing treatment regimen with clinical translation potential in BK.

The combination of high temperature and Vibrio infection worsens summer mortality in the clam Meretrix petechialis by increasing apoptosis and oxidative stress

The interaction between environmental factors and Vibrio in bivalves is not well understood, despite the widely held belief that pathogen infection and seawater temperature significantly impact summer mortality. In the present study, we conducted simulated experiments to explore the effects of high temperature and Vibrio infection on the clam Meretrix petechialis. The survival curve analysis revealed that the combined challenge of high temperature and Vibrio infection (31°C-vibrio) led to significantly higher clam mortality compared to the groups exposed solely to Vibrio (27°C-vibrio), high temperature (31°C-control), and the control condition (27°C-control). Furthermore, PCoA analysis of 11 immune genes indicated that Vibrio infection predominated during the incubation period, with a gradual equilibrium between these factors emerging during the course of the infection. Additionally, our investigations into apoptosis and autophagy processes exhibited significant induction of mTOR and Bcl2 of the 31°C-vibrio group in the early challenge stage, followed by inhibition in the later stage. Oxidative stress analysis demonstrated a substantial additive effect on malondialdehyde (MDA) and glutathione (GSH) content in the combined challenge group compared to the control group. Comparative transcriptome analysis revealed a significant increase in differentially expressed genes related to immunity, such as complement C1q-like protein, C-type lectin, big defensin, and lysozyme, in the 31°C-vibrio group, suggesting that the synergistic effect of high temperature and Vibrio infection triggers more robust antibacterial immune responses. These findings provide critical insights for understanding the infection process and uncovering the causes of summer mortality.

Abstract 1283: Digital spatial profiling of metastatic brain tumors reveals association of the tumor microbiome with immune alterations in the tumor microenvironment

Abstract Introduction: Metastatic brain tumors are associated with significant morbidity and mortality. The microbiome has emerged as a novel hallmark of cancer, with a prominent role in tumor immunity and response to treatment. However, the role of the microbiome in brain tumors, and in particular brain metastasis, is largely unknown. We hypothesized that distinct microbial communities are associated with alterations in the tumor microenvironment in metastatic brain tumors. Methods: To evaluate the role of different microbial communities in brain metastasis, matched stool, saliva, and tumor samples were collected prospectively from patients with metastatic brain tumors who underwent surgical tumor resection at the University of Texas MD Anderson Cancer Center. Stool and saliva samples were sequenced via metagenomic shotgun sequencing and tumor samples were analyzed through 16S rRNA gene sequencing. The tumor microbiome was further characterized through confocal and electron microscopy and culture techniques. Lastly, we conducted digital spatial profiling using the NanoString GeoMx® platform to determine the spatial association of the tumor microbiome with tumor and immune transcriptome. Spatial single-cell transcriptome analysis of bacteria-positive and bacteria-negative cells within the tumor microenvironment is currently in progress using the CosMx® platform (NanoString Inc.). Results: Our computational and experimental analyses demonstrated that bacterial signals could be detected in metastatic brain tumors and exhibit an intracellular localization. Interestingly, we found that the tumor bacterial signatures in brain metastases were composed of commensal oral bacterial taxa but had limited overlap with the gut microbiome. Spatial transcriptome analysis demonstrated that tumor areas with high bacterial signal were associated with innate-immune mediated anti-bacterial responses, suggesting an active host response to intra-tumoral bacteria in metastatic brain tumors. Conclusion: Overall, this work demonstrates the presence of intracellular bacterial signal coupled with an anti-bacterial response within the tumor microenvironment of brain metastases. These findings offer a new perspective on the dynamic interaction between cancer, microbiome, and the brain microenvironment and can inform future mechanistic and translational studies to improve the outcome of brain tumor patients. Citation Format: Golnaz Morad, Ashish V. Damania, Brenda Melendez, Matthew C. Wong, Pranoti V. Sahasrabhojane, Sarah B. Johnson, Manoj Chelvanambi, Florentia Dimitriou, Jillian S. Losh, Nadim J. Ajami, Sherise D. Ferguson, Jennifer A. Wargo. Digital spatial profiling of metastatic brain tumors reveals association of the tumor microbiome with immune alterations in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1283.

CgPHB2 involved in the haemocyte mitophagy in response to Vibrio splendidus stimulation in Pacific oyster Crassostrea gigas

Prohibitin2 (PHB2) is recently identified as a novel inner membrane mitophagy receptor to mediate mitophagy. In the present study, the function of CgPHB2 in mediating mitophagy in response to Vibrio splendidus stimulation was investigated in Crassostrea gigas. CgPHB2 protein was mainly distributed in the cytoplasm of three subpopulations of haemocytes. After V. splendidus stimulation, the expressions of CgPHB2 mRNA in haemocytes were up-regulated significantly at 6, 12 and 24 h, and the abundance of CgPHB2 protein was also enhanced at 12–24 h compared to control group. Furthermore, the green signals of CgPHB2 were colocalized respectively with the red signals of mitochondria and CgLC3 in the haemocytes at 12 h after V. splendidus stimulation, and the co-localization value of CgPHB2 and mtphagy Dye was significantly increased. The direct interaction between CgPHB2 and CgLC3 was simulated by molecular docking. In PHB2-inhibitor Fluorizoline-treated oysters, the mRNA expressions of mitophagy-related genes and the ratio of mitophagy were significantly decreased in haemocytes of oysters after V. splendidus stimulation. All the results collectively suggested that CgPHB2 participated in mediating the haemocyte mitophagy in the antibacterial immune response of oysters.

Cloning and expression analysis of Janus activated kinase family genes from spotted seabass (Lateolabrax maculatus)

Janus kinases (JAKs) are important components of the JAK-STAT signaling pathway and play vital roles in innate immunity, autoimmune diseases, and inflammation. However, information about JAKs remains largely unknown in the spotted seabass, a fish species of Perciformes with great commercial value in the aquaculture industry. The aims of this study are to obtain the complete cDNA sequences of JAKs (JAK1, JAK2A, JAK2B, JAK3 and TYK2) from spotted seabass and to investigate their roles upon stimulation with lipopolysaccharides (LPS) and Edwardsiella tarda, using RT-PCR, PCR and qRT-PCR methods. All five JAK genes from the spotted seabass, each encode more than 1100 amino acids residues. JAK1 and JAK3 consist of 24 exons and 23 introns, whereas JAK2A, JAK2B and TYK2 consist of 23 exons and 22 introns. Furthermore, these five spotted seabass JAKs share high sequence identities with those of other fish species in protein domain analysis, synteny analysis, and phylogenetic analysis. Moreover, these five JAK genes were ubiquitously expressed in all tissues examined from healthy fish, and inducible expressions of JAKs were observed in the intestine, gill, head kidney, and spleen following LPS treatment or E. tarda infection. These findings indicate that all these JAK genes are involved in the antibacterial immunity of the spotted seabass and provide a basis for further understanding the mechanism of JAKs antibacterial response in the spotted sea bass.

Efficient removal of E. coli from wastewater by novel phytofabricated nano-zinc using antibacterial potential, kinetic studies, and response surface methodology

The present investigation explores the antibacterial potential of novel ZnO-NPs synthesized from Acacia nilotica pods extract and immobilized onto sodium alginate beads to control bacterial pollution in wastewater. Phenolics and flavonoids were major phytoconstituents acting as capping, reducing, and stabilizing agents. UV–Vis analysis showed strong absorption band at 340 nm. XRD and TEM revealed hexagonal crystalline structure for zincite of average particles diameter 33.87 and 32.74 nm, respectively. FTIR demonstrated several bands with functional groups (O–H, C-H, C = O, C = C, and C–O–C) involved in ZnO-NPs synthesis. SEM images showed NPs surface completely colonized by E.coli, while EDX spectrum showed signals for zinc (52.94%) and oxygen (26.58%) confirming NPs purity. Adhesion capacity studies revealed ZnO-NPs potential (0.5 g) to remove E.coli after 120 min. Kinetic and isotherm studies indicated that pseudo-second-order model and Freundlich isotherm were best fit describing adhesion mechanism. Electrostatic attraction between negatively charged E.coli and positively charged ZnO-NPs was followed by generation of H2O2 leading to cell apoptosis. Adhesion optimization using Box–Behnken design under response surface methodology was 99.8% at disinfectant dose 30 g/L, contact time 6 h, and E.coli concentration 150 × 107 cfu/mL. For application, real wastewater was treated with removal 98.2%, 97.2%, and 96.5% for total coliform, fecal coliform, and E.coli, respectively, after 6 h. ZnO-NPs showed sustainable efficiency during four consecutive cycles of treatment. The study concluded the efficiency, eco-friendly and cost-effectiveness of phytofabricated ZnO-NPs as disinfectants for wastewater and recommended future studies on large scale for possible wastewater reuse in safe unrestricted irrigation.

A2M possesses anti-bacterial functions by recruiting and enhancing phagocytosis through GRP78 in an echinoderm

Alpha-2-macroglobulin (A2M) is an extracellular macromolecule mainly known for its role as a broad-spectrum protease inhibitor in mammals. However, the immune recognition and regulation mechanisms of A2M in invertebrates are still not well investigated. In the current study, the role of sea cucumber Apostichopus japonicus A2M in the regulation of innate immune responses was explored. We found that AjA2M promotes phagocytosis of Vibrio splendidus in coelomocytes of sea cucumber. Then two major functional structural domains of AjA2M, the thioester domain (TED) and the receptor-binding structural domain (RBD) were cloned. It was found that the AjA2M-TED binds to pathogens while causing Vibrio splendidus aggregation; the AjA2M-RBD interacts with the Glucose Regulated Protein 78 (AjGRP78), subsequently AjGRP78 accelerates the degradation of Vibrio splendidus in lysosomes by facilitating polymerisation and rearrangement of the cytoskeleton. Collectively, the findings together suggest that A2M-GRP78 axis mediates immune signaling pathway of phagocytosis and AjA2M has been characterized to play an essential crucial role in antibacterial immune responses of invertebrates.

Inducible IL-2 production and IL-2+ cell expansion are landmark events for T-cell activation of teleost

As a multipotent cytokine, interleukin (IL)-2 plays important roles in activation, differentiation and survival of the lymphocytes. Although biological characteristics and function of IL-2 have been clarified in several teleost species, evidence regarding IL-2 production at the cellular and protein levels is still scarce in fish due to the lack of reliable antibody. In this study, we developed a mouse anti-Nile tilapia IL-2 monoclonal antibody (mAb), which could specifically recognize IL-2 protein and identify IL-2-producing lymphocytes of tilapia. Using this mAb, we found that CD3+ T cells, but not CD3− lymphocytes, are the main cellular source of IL-2 in tilapia. Under resting condition, both CD3+CD4-1+ T cells and CD3+CD4-1- T cells of tilapia produce IL-2. Moreover, the IL-2 protein level and the frequency of IL-2+ T cells significantly increased once T cells were activated by phytohemagglutinin (PHA) or CD3 plus CD28 mAbs in vitro. In addition, Edwardsiella piscicida infection also induces the IL-2 production and the expansion of IL-2+ T cells in the spleen lymphocytes. These findings demonstrate that IL-2 takes part in the T-cell activation and anti-bacterial adaptive immune response of tilapia, and can serve as an important marker for T-cell activation of teleost fish. Our study has enriched the knowledge regarding T-cell response in fish species, and also provide novel perspective for understanding the evolution of adaptive immune system.

Development of an immune-related diagnostic predictive model for oral lichen planus.

Oral lichen planus (OLP) was a chronic inflammatory disease of unknown etiology with a 1.4% chance of progressing to malignancy. However, it has been suggested in several studies that immune system disorders played a dominant role in the onset and progression of OLP. Therefore, this experiment aimed to develop a diagnostic prediction model for OLP based on immunopathogenesis to achieve early diagnosis and treatment and prevent cancer. In this study, 2 publicly available OLP datasets from the gene expression omnibus database were filtered. In the experimental group (GSE52130), the level of immune cell infiltration was assessed using MCPcounter and ssGSEA algorithms. Subsequently, differential expression analysis and gene set enrichment analysis were performed between the OLP and control groups. The resulting differentially expressed genes were intersected with immunologically relevant genes provided on the immunology database and analysis portal database (ImmPort) website to obtain differentially expressed immunologically relevant genes (DEIRGs). Furthermore, the gene ontology and kyoto encyclopedia of genes and genomes analyses were carried out. Finally, protein-protein interaction network and least absolute shrinkage and selection operator regression analyses constructed a model for OLP. Receiver operating characteristic curves for the experimental and validation datasets (GSE38616) were plotted separately to validate the model's credibility. In addition, real-time quantitative PCR experiment was performed to verify the expression level of the diagnostic genes. Immune cell infiltration analysis revealed a more significant degree of inflammatory infiltration in the OLP group compared to the control group. In addition, the gene set enrichment analysis results were mainly associated with keratinization, antibacterial and immune responses, etc. A total of 774 differentially expressed genes was obtained according to the screening criteria, of which 65 were differentially expressed immunologically relevant genes. Ultimately, an immune-related diagnostic prediction model for OLP, which was composed of 5 hub genes (BST2, RNASEL, PI3, DEFB4A, CX3CL1), was identified. The verification results showed that the model has good diagnostic ability. There was a significant correlation between the 5 hub diagnostic biomarkers and immune infiltrating cells. The development of this model gave a novel insight into the early diagnosis of OLP.

Phospholipase C epsilon-1 (PLCƐ1) mediates macrophage activation and protection against tuberculosis.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) infects up to a quarter of the world's population. Although immune responses can control Mtb infection, 5%-10% of infected individuals can progress to active TB disease (progressors). A myriad of host factors regulate disease progression in TB and a better understanding of immune correlates of protection and disease is pivotal for the development of new therapeutics. Comparison of human whole blood transcriptomic metadata with that of macaque TB progressors and Mtb-infected diversity outbred mice (DO) led to the identification of differentially regulated gene (DEG) signatures, associated with TB progression or control. The current study assessed the function of Phospholipase C epsilon (PLCƐ1), the top downregulated gene across species in TB progressors, using a gene-specific knockout mouse model of Mtb infection and in vitro Mtb-infected bone marrow-derived macrophages. PLCƐ1 gene expression was downregulated in TB progressors across species. PLCε1 deficiency in the mouse model resulted in increased susceptibility to Mtb infection, coincident accumulation of lung myeloid cells, and reduced ability to mount antibacterial responses. However, PLCε1 was not required for the activation and accumulation of T cells in mice. Our results suggest an important early role for PLCƐ1 in shaping innate immune response to TB and may represent a putative target for host-directed therapy.

Characterization and immunological effect of outer membrane vesicles from Pasteurella multocida on macrophages

Pasteurella multocida is an important bacterial pathogen that can cause diseases in both animals and humans. Its elevated morbidity and mortality rates in animals result in substantial economic repercussions within the livestock industry. The prevention of diseases caused by P. multocida through immunization is impeded by the absence of a safe and effective vaccine. Outer membrane vesicles (OMVs) secreted from the outer membrane of Gram-negative bacteria are spherical vesicular structures that encompass an array of periplasmic components in conjunction with a diverse assortment of lipids and proteins. These vesicles can induce antibacterial immune responses within the host. P. multocida has been shown to produce OMVs. Nonetheless, the precise characteristics and immunomodulatory functions of P. multocida OMVs have not been fully elucidated. In this study, OMVs were isolated from P. multocida using an ultrafiltration concentration technique, and their morphology, protein constitution, and immunomodulatory properties in RAW264.7 cells were studied. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) revealed that the OMVs exhibited typical spherical and bilayered lipid vesicular architecture, exhibiting an average diameter of approximately 147.5 nm. The yield of OMVs was 2.6 × 1011 particles/mL. Proteomic analysis revealed a high abundance of membrane-associated proteins within P. multocida OMVs, with the capability to instigate the host’s immune response. Furthermore, OMVs stimulated the proliferation and cellular uptake of macrophages and triggered the secretion of cytokines, such as TNF-ɑ, IL-1β, IL-6, IL-10, and TGF-β1. Consequently, our results indicated that OMVs from P. multocida could directly interact with macrophages and regulate their immune function in vitro. These results supported the prospective applicability of P. multocida OMVs as a platform in the context of vaccine development.Key points• Preparation and characterization of P. multocida OMVs.• P. multocida OMVs possess a range of antigens and lipoproteins associated with the activation of the immune system.• P. multocida OMVs can activate the proliferation, internalization, and cytokine secretion of macrophages in vitro.

MARCKS Inhibition Alters Bovine Neutrophil Responses to Salmonella Typhimurium.

Neutrophils are innate immune cells that respond quickly to sites of bacterial infection and play an essential role in host defense. Interestingly, some bacterial pathogens benefit from exuberant neutrophil inflammation. Salmonella is one such pathogen that can utilize the toxic mediators released by neutrophils to colonize the intestine and cause enterocolitis. Because neutrophils can aid gut colonization during Salmonella infection, neutrophils represent a potential host-directed therapeutic target. Myristoylated alanine-rich C-kinase substrate (MARCKS) is an actin-binding protein that plays an essential role in many neutrophil effector responses. We hypothesized that inhibition of MARCKS protein would alter bovine neutrophil responses to Salmonella Typhimurium (STm) ex vivo. We used a MARCKS inhibitor peptide to investigate the role of MARCKS in neutrophil responses to STm. This study demonstrates that MARCKS inhibition attenuated STm-induced neutrophil adhesion and chemotaxis. Interestingly, MARCKS inhibition also enhanced neutrophil phagocytosis and respiratory burst in response to STm. This is the first report describing the role of MARCKS protein in neutrophil antibacterial responses.

Application of Bacillus Coagulans as Paraprobiotic Against Acute Hepatopancreatic Necrosis Disease in Shrimp.

Paraprobiotics, known as non-viable or ghost probiotics, have attracted attention for their benefits over live microbial cells. This study was designed to investigate the paraprobiotic effects of heat-killed Bacillus coagulans on the white leg shrimp Litopenaeus vannamei. The paraprobiotic formulation was prepared in three different concentrations including B. coagulans 1 (107 cells g-1 diet), B. coagulans 2 (108 cells g-1 diet), and B. coagulans 3 (109 cells g-1 diet) through heat inactivation method. Preliminary toxicity assessments revealed that post-larvae shrimps (mean weight ± SE: 0.025 ± 0.007g) treated with B. coagulans 1, 2 and 3 paraprobiotic formulations exhibited no mortality, confirming the non-toxic nature of the formulated diet. In a 90-day feeding trial involving juvenile shrimps (mean weight ± SE: 0.64 ± 0.05g), growth parameters and feed conversion ratios improved in all experimental groups. Subsequently, these shrimps were challenged with Vibrio parahaemolyticus, revealing that paraprobiotic-fed shrimps exhibited significant survival rate improvements. Oxidative stress-related enzyme activities, such as superoxide dismutase and catalase, increased in paraprobiotic-fed shrimps post-Vibrio challenge, while the challenged control group showed decreased activity (p < 0.001). Nitric oxide levels are also increased in paraprobiotic-treated shrimp, with B. coagulans 3 showing a significant rise in nitric oxide activity (p < 0.001). This study further demonstrated the positive impact of paraprobiotic treatment on digestive enzymes, immune-related parameters (e.g., total hemocyte count, prophenoloxidase, and respiratory burst activity), and overall disease resistance. These findings suggest that B. coagulans paraprobiotics have the potential to enhance antioxidant, antibacterial, and immune-related responses in L. vannamei, making them a valuable addition to shrimp aquaculture.

Polyamide Electrospun Nanofibers Functionalized with Silica and Titanium Dioxide Nanoparticles for Efficient Dye Removal

In this work, novel multifunctional electrospun nanofibrous membranes made of polyamide (PA6) and loaded with silica (SiO2) and/or titanium dioxide (TiO2) nanoparticles were fabricated. SiO2 NPs were first prepared and then characterized by TEM, FE-SEM, and FTIR, and by using XRD techniques, confirming the formation of cristobalite tetragonal crystals with high purity. Different nanofibrous mats, loaded with SiO2 NPs, TiO2 NPs, or both SiO2 and TiO2 NPs, were investigated. Morphological studies indicated that SiO2 and TiO2 nanoparticles tend to be arranged along the fiber surface, also promoting the formation of anatase nanorods when they are mixed into the nanofibers. In this last scenario, mechanical tests have demonstrated that the presence of SiO2 contributed to balancing the mechanical response of fibers that are negatively affected by the presence of TiO2 NPs—as confirmed by tensile tests. More interestingly, the presence of SiO2 did not negatively affect the antibacterial response against different bacteria populations (i.e., Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Bacillus subtilis, and Candida albicans), which is mainly ascribable to the presence of TiO2 particles. Accordingly, the TiO2- and TiO2/SiO2-loaded fibers showed higher methylene blue (MB) absorption values—i.e., 26 mg/g and 27 mg/g—respectively, compared to the SiO2-loaded fibers (23 mg/g), with kinetics in good agreement with the second-order kinetic model. The obtained findings pave the way for the formation of novel antibacterial membranes with a promising use in water purification.

Identification of prognostic biomarkers of smoking-related lung cancer.

The early diagnosis and effective prognostic treatment measures for lung cancer are still limited, leading to a 5-year survival rate of less than 15% for these patients. Smoking is one of the causes of lung cancer, but it is not the initial carcinogenic factor. It is not clear what specific mechanism cigarette induces lung cancer, and there is a lack of research on the relationship between related genes and the prognosis of patients with smoking lung cancer. The objective of this study was to provide new theoretical evidence and potential therapeutic targets for the mechanisms of smoking-related lung cancer formation. The gene expression profile data from the GSE12428 dataset which includes 63 lung cancer and normal tissue pairs were downloaded from the Gene Expression Omnibus (GEO) database, and data from smokers with lung cancer [both lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC)] from The Cancer Genome Atlas (TCGA) database were analyzed. The differential genes in smokers with lung cancer were screened using the linear model for microarray data via R software. The differential gene enrichment analysis was performed using the online analysis software Database for Annotation, Visualization and Integrated Discovery (DAVID). The expression levels of differential genes and their correlation with patient tumor clinical stage were analyzed using gene expression profiling interactive analysis (GEPIA). The overall survival rate was analyzed using Kaplan-Meier curves. In the GSE12428 dataset, 225 upregulated genes and 565 downregulated genes were identified in cancer tissues; based on smoking status, 1 upregulated gene and 4 downregulated genes were identified. Among smokers who also had lung cancer, 4 genes were downregulated, namely CSH1, BPIFA1, SLPI, and SCGB3A1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that these genes were mainly associated with biological functions such as antibacterial response, humoral immune response, and response to external stimuli. Among them, BPIFA1, SLPI, and SCGB3A1 expression was decreased in lung cancer tissues, with SCGB3A1 showing significant differences. Additionally, high expression of SCGB3A1 was associated with favorable prognosis in patients with lung cancer. Three genes BPIFA1, SLPI and SCGB3A1, were identified as being associated with smokers with lung cancer, with SCGB3A1 showing a close correlation with patient prognosis. These findings provide potential new targets for the treatment of lung cancer. Certainly, this study needs to more investigate the mechanism of these genes regulation.

Periodontitis and brain magnetic resonance imaging markers of Alzheimer's disease and cognitive aging.

We examined the association of clinical, microbiological, and host response features of periodontitis with MRI markers of atrophy/cerebrovascular disease in the Washington Heights Inwood Columbia Aging Project (WHICAP) Ancillary Study of Oral Health. We analyzed 468 participants with clinical periodontal data, microbial plaque and serum samples, and brain MRIs. We tested the association of periodontitis features with MRI features, after adjusting for multiple risk factors for Alzheimer's disease/Alzheimer's disease-related dementia (AD/ADRD). In fully adjusted models, having more teeth was associated with lower odds for infarcts, lower white matter hyperintensity (WMH) volume, higher entorhinal cortex volume, and higher cortical thickness. Higher extent of periodontitis was associated with lower entorhinal cortex volume and lower cortical thickness. Differential associations emerged between colonization by specific bacteria/serum antibacterial IgG responses and MRI outcomes. In an elderly cohort, clinical, microbiological, and serological features of periodontitis were associated with MRI findings related to ADRD risk. Further investigation of causal associations is warranted.

New bis-hydantoin/thiohydantoin derivatives: Regioselective synthesis, antibacterial activity, molecular docking, and computational insights

Concerning the reported biological activities of bis-heterocycles, hydantoin, and thiohydantoin moieties, a series of some new bis-hydantoins/thiohydantoins have been prepared, characterized, and screened for their antimicrobial properties. The regioselectivity of the synthetic reactions was discussed and chemical structures of products were elucidated using spectroscopic techniques in addition to elemental analysis. DFT calculations with the IEF-PCM model, to mimic the implicit solvation, have been performed to study the mechanism of reaction as well as the molecular structures and the relative stabilities of the synthesized compounds. The antimicrobial results show that some bis-hydantoin compounds exhibited high antibacterial response against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. The inhibitory activity of synthesized compounds may be due to the hydrogen acceptor/donor (HAD) behavior of substituted function groups like thiocarbonyl, carbonyl, acetyl, NH, and OH. The synthetic potential and antimicrobial activities of all compounds under investigation were confirmed using molecular docking simulation into the active sites of different kinds of proteins.

Growth and longevity modulation through larval environment mediate immunosenescence and immune strategy of Tenebrio molitor

BackgroundThe Disposable Soma Theory of aging suggests a trade-off between energy allocation for growth, reproduction and somatic maintenance, including immunity. While trade-offs between reproduction and immunity are well documented, those involving growth remain under-explored. Rapid growth might deplete resources, reducing investment in maintenance, potentially leading to earlier or faster senescence and a shorter lifespan. However, rapid growth could limit exposure to parasitism before reaching adulthood, decreasing immunity needs. The insect immunity’s components (cellular, enzymatic, and antibacterial) vary in cost, effectiveness, and duration. Despite overall immunity decline (immunosenescence), its components seem to age differently. We hypothesize that investment in these immune components is adjusted based on the resource cost of growth, longevity, and the associated risk of parasitism.ResultsWe tested this hypothesis using the mealworm beetle, Tenebrio molitor as our experimental subject. By manipulating the larval environment, including three different temperatures and three relative humidity levels, we achieved a wide range of growth durations and longevities. Our main focus was on the relationship between growth duration, longevity, and specific immune components: hemocyte count, phenoloxidase activity, and antibacterial activity. We measured these immune parameters both before and after exposing the individuals to a standard bacterial immune challenge, enabling us to assess immune responses. These measurements were taken in both young and older adult beetles. Upon altering growth duration and longevity by modifying larval temperature, we observed a more pronounced investment in cellular and antibacterial defenses among individuals with slow growth and extended lifespans. Intriguingly, slower-growing and long-lived beetles exhibited reduced enzymatic activity. Similar results were found when manipulating larval growth duration and adult longevity through variations in relative humidity, with a particular focus on antibacterial activity.ConclusionThe impact of growth manipulation on immune senescence varies by the specific immune parameter under consideration. Yet, in slow-growing T. molitor, a clear decline in cellular and antibacterial immune responses with age was observed. This decline can be linked to their initially stronger immune response in early life. Furthermore, our study suggests an immune strategy favoring enhanced antibacterial activity among slow-growing and long-lived T. molitor individuals.