Enhancing microbial superoxide generation and conversion to hydroxyl radicals for enhanced bioremediation using iron-binding ligands.

Harnessing bacteria for superoxide production in bioremediation holds immense promise, yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide. This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain, a prevalent soil bacterial genus. Our research reveals that introducing a carbon source along with specific iron-binding ligands, including deferoxamine (DFO), diethylenetriamine pentaacetate (DTPA), citrate, and oxalate, robustly augments microbial superoxide generation. Moreover, our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(III)/Fe(II) and superoxide. Remarkably, among the tested ligands, only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(III). We identify an optimal Fe(III) to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture. This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals, significantly elevating bioremediation performance. Furthermore, our study reveals that DTPA augments superoxide production in cultures of diverse soils, with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation. This emphasizes the universal applicability of DTPA across multiple bacterial genera. In conclusion, our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals. These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation, offering innovative solutions for addressing environmental contamination challenges.

[Retracted] Downregulated expression levels of USP46 promote the resistance of ovarian cancer to cisplatin and are regulated by PUM2.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that certain of the immunohistochemical data shown in Fig. 1D and the flow cytometric data in Fig. 3K were strikingly similar to data appearing in different form in other papers by different authors at different research institutes that were under consideration for publication at around the same time.  Owing to the fact that the contentious data in the above article were already under consideration for publication prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 23: 263, 2021; DOI: 10.3892/mmr.2021.11902].

Expression Pattern of RpCSP6 from Rhopalosiphum padi and Its Binding Mechanism with Deltamethrin: Insights into Chemosensory Protein-Mediated Insecticide Resistance.

The mechanisms of insecticide resistance are complex. Recent studies have revealed a novel mechanism involving the chemosensory system in insecticide resistance. However, the specific binding mechanism between olfactory-related genes and insecticides needs to be clarified. In this study, the binding mechanism between pyrethroid insecticide deltamethrin and RpCSP6 from Rhopalosiphum padi was investigated by using computational and multiple experimental methods. RpCSP6 was expressed in different tissues and developmental stages of R. padi and can be induced by deltamethrin. Knockdown of RpCSP6 significantly increased the susceptibility of R. padi to deltamethrin. The binding affinity of RpCSP6 to 24 commonly used insecticides was measured. Seven key residues were found to steadily interact with deltamethrin, indicating their significance in the binding affinity to the insecticide. Our research provided insights for effectively analyzing the binding mechanism of insect CSPs with insecticides, facilitating the development of new and effective insecticides that target insect CSPs.

Toxicity of rare earth elements (REEs) to marine organisms: Using species sensitivity distributions to establish water quality guidelines for protecting marine life.

A lack of chronic rare earth element (REE) toxicity data for marine organisms has impeded the establishment of numerical REE water quality benchmarks (e.g., guidelines) to protect marine life and assess ecological risk. This study determined the chronic no (significant) effect concentrations (N(S)ECs) and median-effect concentrations (EC50s) of eight key REEs (yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), gadolinium (Gd), dysprosium (Dy) and lutetium (Lu)) for 30 coastal marine organisms (encompassing 22 phyla and five trophic levels from temperate and tropical habitats). Organisms with calcifying life stages were most vulnerable to REEs, which competitively inhibit calcium uptake. The most sensitive organism was a sea urchin, with N(S)ECs ranging from 0.64 µg/L for Y to 1.9 µg/L for La and Pr, and EC50s ranging from 4.3 µg/L for Y to 14.4 µg/L for Pr. Conversely, the least sensitive organism was a cyanobacterium, with N(S)ECs ranging from 21 µg/L for Y to 73 µg/L for Pr, and EC50s ranging from 153 µg/L for Y to 535 µg/L for La. Median sensitivity varied 215-fold across all organisms. The two-fold difference in median toxicity (µmol/L EC50) among REEs (Y∼Gd > Lu∼Nd∼Dy∼Ce > La∼Pr) was attributed to offset differences in binding affinity (log K) to cell surface receptors and the percentage of free metal ion (REE3+) in the test waters. The toxicity (EC50) of the remaining REEs (samarium, europium, terbium, holmium, thulium and ytterbium) was predicted using a combination of physicochemical data and measured EC50s for the eight tested REEs, with good agreement between predicted and measured EC50s for selected organisms. Numerical REE water quality guidelines to protect marine life were established using species sensitivity distributions (e.g., for 95 % species protection, values ranged from 1.1 µg/L for Y to 3.0 µg/L for La, Pr or Lu).

Propofol does not alter the protein binding and unbound concentration of lidocaine at clinically targeted plasma concentrations in vitro - A short communication.

BACKGROUND: Intravenous lidocaine is increasingly used as an analgesic adjunct during general anaesthesia. Lidocaine is highly protein-bound and changes to binding can alter drug efficacy or toxicity. We aimed to measure the effect of various propofol and lidocaine plasma concentration combinations on the protein binding and concentration of lidocaine in vitro. METHODS: Known targeted concentrations of propofol and lidocaine were added to drug-free human plasma in vitro. Samples were prepared and analysed in various clinically relevant concentration combinations; propofol at 0, 2, 4 and 6 µg/mL, and lidocaine at 1, 3 and 5 µg/mL. The total and unbound concentrations of lidocaine were measured by ultra-high performance liquid chromatography-mass spectrometry and percentage protein binding was determined. Data were presented as mean and standard deviation (SD) and differences between analysed groups. RESULTS: The overall mean protein binding of lidocaine was 68.8% (SD 5.5, range 57.5-80.9%). Beta regression analysis revealed no statistically significant difference in lidocaine percentage binding across a range of propofol and lidocaine concentration combinations. CONCLUSION: Propofol did not alter the unbound and free pharmacologically active proportion of lidocaine at different clinically targeted concentrations of propofol and lidocaine in plasma in vitro. The percentage of plasma protein binding of lidocaine in this study was consistent with previously published results.

Acquired Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Resistance of Human Colorectal Cancer Cells Is Linked to Histone Acetylation and Is Synergistically Ameliorated by Combination with HDAC Inhibitors.

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive target for the treatment of various malignancies; however, its therapeutic potential is limited because of the frequent occurrence of tumor cell resistance. In this study, we determined whether TRAIL resistance acquired by repeated administration could be overcome by HDAC inhibition in human colorectal cancer cells. METHODS: TRAIL-resistant HCT116 human colorectal cancer cells (HCT116-TR) were generated by repeated treatment with 10 and 25 ng/mL TRAIL twice weekly for 28 days. RESULTS: The resulting TRAIL-resistant cells were noncross-resistant to other chemotherapeutic agents. The levels of histone acetylation-related proteins, such as ac-histone H4 and HDAC1, were altered in HCT116-TR cells compared with the parental HCT116 cell line. The combined treatment with TRAIL and HDAC inhibitors significantly increased apoptosis in HCT116-TR cells and indicated a synergistic effect. The mechanism by which HDAC inhibition sensitizes HCT116-TR cells to TRAIL is dependent on the intrinsic pathway. In addition, we found that HDAC inhibition enhanced the sensitivity of cells to TRAIL through mitogen-activated protein kinases/CCAAT/enhancer-binding protein homologs of protein-dependent upregulation of death receptor 5. CONCLUSION: These results suggest that histone acetylation is responsible for acquired TRAIL resistance after repeated exposure and acquired resistance to TRAIL may be overcome by combination therapies with HDAC inhibitors.

Recent developments in understanding RIG-I's activation and oligomerization.

Insights into mechanisms driving either activation or inhibition of immune response are crucial in understanding the pathology of various diseases. The differentiation of viral from endogenous RNA in the cytoplasm by pattern-recognition receptors, such as retinoic acid-inducible gene I (RIG-I), is one of the essential paths for timely activation of an antiviral immune response through induction of type I interferons (IFN). In this mini-review, we describe the most recent developments centered around RIG-I's structure and mechanism of action. We summarize the paradigm-changing work over the past few years that helped us better understand RIG-I's monomeric and oligomerization states and their role in conveying immune response. We also discuss potential applications of the modulation of the RIG-I pathway in preventing autoimmune diseases or induction of immunity against viral infections. Overall, our review aims to summarize innovative research published in the past few years to help clarify questions that have long persisted around RIG-I.

Vitamin D Binding Protein (DBP), Free Calcidiol, and Total Calcitriol in Adults from Northern Greece.

Background: An ongoing debate has been raised on whether is better to use total or free calcidiol as a screening test in the population. Methods: In winter and summer, free calcidiol, total calcitriol, and vitamin D binding protein (DBP) concentrations were determined by immunoenzymatic assays in 326 adults (161 males, 165 females). These included 99 osteoporotic patients, 53 type 1 and 51 type 2 diabetics, and 123 athletic healthy persons, all from northern Greece. Results: In the whole sample, free calcidiol mean concentrations differed significantly (p < 0.001) between males (5.53 pg/ml) and females (4.68 pg/ml). Free calcidiol was significantly greater in the athletic healthy group (6.02 pg/ml) than in the three patient groups, and lowest in the osteoporosis group (3.69 pg/ml). Total calcitriol mean concentration did not differ significantly between genders in the whole sample (p = 0.896) or in the study groups, except for type 2 diabetics (males 38.33 pg/ml, females 54.52 pg/ml, p = 0.001). It was significantly less in the osteoporotics (34.61 pg/ml) than in the athletic healthy group (41.65 pg/ml, p = 0.037) and type 1 diabetics (43.73 pg/ml, p = 0.030), whereas it did not differ significantly between the other study groups. The DBP mean concentrations were not significantly different between genders in the whole sample and the study groups nor among the study groups (p = 0.467). Conclusion: Comparisons with our previously reported results of total calcidiol suggest the measurement of free calcidiol offers nothing more than that, and total calcitriol is not a sensitive measure for assessing vitamin D status.

Loss of monopolar spindle-binding protein 3B expression promotes colorectal cancer invasiveness by activation of target of rapamycin kinase/autophagy signaling.

BACKGROUND: Monopolar spindle-binding protein 3B (MOB3B) functions as a signal transducer and altered MOB3B expression is associated with the development of human cancers. AIM: To investigate the role of MOB3B in colorectal cancer (CRC). METHODS: This study collected 102 CRC tissue samples for immunohistochemical detection of MOB3B expression for association with CRC prognosis. After overexpression and knockdown of MOB3B expression were induced in CRC cell lines, changes in cell viability, migration, invasion, and gene expression were assayed. Tumor cell autophagy was detected using transmission electron microscopy, while nude mouse xenograft experiments were performed to confirm the in-vitro results. RESULTS: MOB3B expression was reduced in CRC vs normal tissues and loss of MOB3B expression was associated with poor CRC prognosis. Overexpression of MOB3B protein in vitro attenuated the cell viability as well as the migration and invasion capacities of CRC cells, whereas knockdown of MOB3B expression had the opposite effects in CRC cells. At the molecular level, microtubule-associated protein light chain 3 II/I expression was elevated, whereas the expression of matrix metalloproteinase (MMP)2, MMP9, sequestosome 1, and phosphorylated mechanistic target of rapamycin kinase (mTOR) was downregulated in MOB3B-overexpressing RKO cells. In contrast, the opposite results were observed in tumor cells with MOB3B knockdown. The nude mouse data confirmed these in-vitro findings, i.e., MOB3B expression suppressed CRC cell xenograft growth, whereas knockdown of MOB3B expression promoted the growth of CRC cell xenografts. CONCLUSION: Loss of MOB3B expression promotes CRC development and malignant behaviors, suggesting a potential tumor suppressive role of MOB3B in CRC by inhibition of mTOR/autophagy signaling.

Biomolecular Interactions and Anticancer Mechanisms of Ru(II)-Arene Complexes of Cinnamaldehyde-Derived Thiosemicarbazone Ligands: Analysis Combining In Silico and In Vitro Approaches.

Our study focuses on synthesizing and exploring the potential of three N-(4) substituted thiosemicarbazones derived from cinnamic aldehyde, alongside their Ru(II)-(η6 -p-cymene)/(η6-benzene) complexes. The synthesized compounds were comprehensively characterized using a range of analytical techniques, including FT-IR, UV-visible spectroscopy, NMR (1H, 13C), and HRMS. We investigated their electronic and physicochemical properties via density functional theory (DFT). X-ray crystal structures validated structural differences identified by DFT. Molecular docking predicted promising bioactivities, supported by experimental observations. Notably, docking with EGFR suggested an inhibitory potential against this cancer-related protein. Spectroscopic titrations revealed significant DNA/BSA binding affinities, particularly with DNA intercalation and BSA hydrophobic interactions. RuPCAM displayed the strongest binding affinity with DNA (Kb = 6.23 × 107 M-1) and BSA (Kb = 9.75 × 105 M-1). Assessed the cytotoxicity of the complexes on cervical cancer cells (HeLa), and breast cancer cells (MCF-7 and MDA-MB 231), revealing remarkable potency. Additionally, selectivity was assessed by examining MCF-10a normal cell lines. The active complexes were found to trigger apoptosis, a vital cellular process crucial for evaluating their potential as anticancer agents utilizing staining assays and flow cytometry analysis. Intriguingly, complexation with Ru(II)-arene precursors significantly amplified the bioactivity of thiosemicarbazones, unveiling promising avenues toward the creation of powerful anticancer agents.

The Iron Binding Ability Maps the Fate of Food-Derived Transferrins: A Review.

As the demand for lactoferrin increases, the search for cost-effective alternative proteins becomes increasingly important. Attention naturally turns to other members of the transferrin family such as ovotransferrin. The iron-binding abilities of these proteins influence their characteristics, although the underlying mechanisms remain unclear. This overview systematically summarizes the effects of the iron-binding ability on the fate of food-derived transferrins (lactoferrin and ovotransferrin) and their potential applications. The findings indicate that iron-binding ability significantly influences the structure of food-derived transferrins, particularly their tertiary structure. Changes in structure influence their physicochemical properties, which, in turn, lead to different behaviors in response to environmental variations. Thus, these proteins exhibit distinct digestive characteristics by the time they reach the small intestine, ultimately performing varied physiological functions in vivo. Consequently, food-derived transferrins with different iron-binding states may find diverse applications. Understanding this capability is essential for developing food-derived transferrins and driving innovation in lactoferrin-related industries.

Synergistic effects of novel penicillin-binding protein 1A amino acid substitutions contribute to high-level amoxicillin resistance of Helicobacter pylori.

The growing resistance to amoxicillin (AMX)-one of the main antibiotics used in Helicobacter pylori eradication therapy-is an increasing health concern. Several mutations of penicillin-binding protein 1A (PBP1A) are suspected of causing AMX resistance; however, only a limited set of these mutations have been experimentally explored. This study aimed to investigate four PBP1A mutations (i.e., T558S, N562H, T593A, and G595S) carried by strain KIN76, a high-level AMX-resistant clinical H. pylori isolate with an AMX minimal inhibition concentration (MIC) of 2 µg/mL. We transformed a recipient strain 26695 with the DNA containing one to four mutation allele combinations of the pbp1 gene from strain KIN76. Transformants were subjected to genomic exploration and antimicrobial susceptibility testing. The resistance was transformable, and the presence of two to four PBP1A mutations (T558S and N562H, or T593A and G595S), rather than separate single mutations, was necessary to synergistically increase the AMX MIC up to 16-fold compared with the wild-type (WT) strain 26695. An AMX binding assay of PBP1A was performed using these strains, and binding was visualized by chasing Bocillin, a fluorescent penicillin analog. This revealed that all four-mutation allele-transformed strains exhibited decreased affinity to AMX on PBP1A than the WT. Protein structure modeling indicated that functional modifications occur as a result of these amino acid substitutions. This study highlights a new synergistic AMX resistance mechanism and establishes new markers of AMX resistance in H. pylori.IMPORTANCEThe development of resistance to antibiotics, including amoxicillin, is hampering the eradication of Helicobacter pylori infection. The identification of mechanisms driving this resistance is crucial for the development of new therapeutic strategies. We have demonstrated in vitro the synergistic role of novel mutations in the pbp1 gene of H. pylori that is suspected to drive amoxicillin resistance. Also deepening our understanding of amoxicillin resistance mechanisms, this study establishes new molecular markers of amoxicillin resistance that may be useful in molecular-based antibiotic susceptibility testing approaches for clinical practice or epidemiologic investigations.

Activation of skeletal carbohydrate-response element binding protein (ChREBP)-mediated de novo lipogenesis increases intramuscular fat content in chickens.

The intracellular lipids in muscle cells of farm animals play a crucial role in determining the overall intramuscular fat (IMF) content, which has a positive impact on meat quality. However, the mechanisms underlying the deposition of lipids in muscle cells of farm animals are not yet fully understood. The purpose of this study was to determine the roles of carbohydrate-response element binding protein (ChREBP) and fructose in IMF deposition of chickens. For virus-mediated ChREBP overexpression in tibialis anterior (TA) muscle of chickens, seven 5-d-old male yellow-feather chickens were used. At 10 d after virus injection, the chickens were slaughtered to obtain TA muscles for analysis. For fructose administration trial, sixty 9-wk-old male yellow-feather chickens were randomly divided into 2 groups, with 6 replicates per group and 5 chickens per replicate. The chickens were fed either a basal diet or a basal diet supplemented with 10% fructose (purity ≥ 99%). At 4 wk later, the chickens were slaughtered, and breast and thigh muscles were collected for analysis. The results showed that the skeletal ChREBP mRNA levels were positively associated with IMF content in multiple species, including the chickens, pigs, and mice (P < 0.05). ChREBP overexpression increased lipid accumulation in both muscle cells in vitro and the TA muscles of mice and chickens in vivo (P < 0.05), by activation of the de novo lipogenesis (DNL) pathway. Moreover, activation of ChREBP by dietary fructose administration also resulted in increased IMF content in mice and notably chickens (P < 0.05). Furthermore, the lipidomics analysis revealed that ChREBP activation altered the lipid composition of chicken IMF and tented to improve the flavor profile of the meat. In conclusion, this study found that ChREBP plays a pivotal role in mediating the deposition of fat in chicken muscles in response to fructose-rich diets, which provides a novel strategy for improving meat quality in the livestock industry.

Tata-box-binding protein-associated factor 15 as a new potential marker in gastrointestinal tumors.

In this editorial, the roles of tata-box-binding protein-associated factor 15 (TAF15) in oncogenesis, tumor behavior, and as a therapeutic target in cancers in the context of gastrointestinal (GI) tumors are discussed concerning the publication by Guo et al. TAF15 is a member of the FET protein family with a comprehensive range of cellular processes. Besides, evidence has shown that TAF15 is involved in many diseases, including cancers. TAF15 contributes to carcinogenesis and tumor behavior in many tumors. Besides, its relationship with the mitogen-activated protein kinases (MAPK) signaling pathway makes TAF15 a new target for therapy. Although, the fact that there is few studies investigating the expression of TAF15 constitutes a potential limitation in GI system, the association of TAF15 expression with aggressive tumor behavior and, similar to other organ tumors, the influence of TAF15 on the MAPK signaling pathway emphasize that this protein could serve as a new molecular biomarker to predict tumor behavior and target therapeutic intervention in GI cancers. In conclusion, more studies should be performed to better understand the prognostic and therapeutic role of TAF15 in GI tumors, especially in tumors resistant to therapy.

Periphery Pre-S1 and S1 helix nexus for PIP2 at TRPC3 channel.

Transient receptor potential canonical 3 (TRPC3) is a calcium-permeable, non-selective cation channel known to be regulated by components of the phospholipase C (PLC)-mediated signaling pathway, such as Ca2+, diacylglycerol (DAG) and phosphatidylinositol 4,5-biphosphate (PI(4,5)P2). However, the molecular gating mechanism by these regulators is not yet fully understood, especially its regulation by PI(4,5)P2, despite the importance of this channel in cardiovascular pathophysiology. Recently, Clarke et al. (2024) have reported that PI(4,5)P2 is a positive modulator for TRPC3 using molecular dynamics simulations and patch-clamp techniques. They have demonstrated a multistep gating mechanism of TRPC3 with the binding of PI(4,5)P2 to the lipid binding site located at the pre-S1/S1 nexus, and the propagation of PI(4,5)P2 sensing to the pore domain via a salt bridge between the TRP helix and the S4-S5 linker.

Genome-wide mapping of the binding sites of myocyte enhancer factor 2A in chicken primary myoblasts.

Myocyte enhancer factor 2A (MEF2A) is a transcription factor that plays a critical role in cell proliferation, differentiation and apoptosis. In contrast to the wide characterization of its regulation mechanism in mammalian skeletal muscle, its role in chickens is limited. Especially, its wide target genes remain to be identified. Therefore, we utilized Cleavage Under Targets and Tagmentation (CUT&Tag) technology to reveal the genome-wide binding profile of MEF2A in chicken primary myoblasts thus gaining insights into its potential role in muscle development. Our results revealed that MEF2A binding sites were primarily distributed in intergenic and intronic regions. Within the promoter region, although only 8.87% of MEF2A binding sites were found, these binding sites were concentrated around the transcription start site (TSS). Following peak annotation, a total of 1903 genes were identified as potential targets of MEF2A. Gene Ontology (GO) enrichment analysis further revealed that MEF2A target genes may be involved in the regulation of embryonic development in multiple organ systems, including muscle development, gland development, and visual system development. Moreover, a comparison of the MEF2A target genes identified in chicken primary myoblasts with those in mouse C2C12 cells revealed 388 target genes are conserved across species, 1515 target genes are chicken specific. Among these conserved genes, ankyrin repeat and SOCS box containing 5 (ASB5), transmembrane protein 182 (TMEM182), myomesin 2 (MYOM2), leucyl and cystinyl aminopeptidase (LNPEP), actinin alpha 2 (ACTN2), sorbin and SH3 domain containing 1 (SORBS1), ankyrin 3 (ANK3), sarcoglycan delta (SGCD), and ORAI calcium release-activated calcium modulator 1 (ORAI1) exhibited consistent expression patterns with MEF2A during embryonic muscle development. Finally, TMEM182, as an important negative regulator of muscle development, has been validated to be regulated by MEF2A by dual-luciferase and quantitative real-time PCR (qPCR) assays. In summary, our study for the first time provides a wide landscape of MEF2A target genes in chicken primary myoblasts, which supports the active role of MEF2A in chicken muscle development.

Evidence that the SARS-CoV-2 S protein undergoes a conformational change at the Golgi complex that leads to the formation of virus neutralising antibody binding epitopes in the S1 protein subunit.

Recombinant SARS-CoV-2 S protein expression was examined in Vero cells by imaging using the human monoclonal antibody panel (PD4, PD5, sc23, and sc29). The PD4 and sc29 antibodies recognised conformational specific epitopes in the S2 protein subunit at the Endoplasmic reticulum and Golgi complex. While PD5 and sc23 detected conformationally specific epitopes in the S1 protein subunit at the Golgi complex, only PD5 recognised the receptor binding domain (RBD). A comparison of the staining patterns of PD5 with non-conformationally specific antibodies that recognises the S1 subunit and RBD suggested the PD5 recognised a conformational structure within the S1 protein subunit. Our data suggests the antibody binding epitopes recognised by the human monoclonal antibodies formed at different locations in the secretory pathway during S protein transport, but a conformational change in the S1 protein subunit at the Golgi complex formed antibody binding epitopes that are recognised by virus neutralising antibodies.

Identification of chitinase from Bacillus velezensis strain S161 and its antifungal activity against Penicillium digitatum.

Previous studies have demonstrated the presence of chitinase in Bacillus velezensis through extensive genomic sequencing and experimental analyses. However, the detailed structure, functional roles, and antifungal activity of these chitinases remain poorly characterized. In this study, genomic screening identified three genes-chiA, chiB, and lpmo10-associated with chitinase degradation in B. velezensis S161. These genes encode chitinases ChiA and ChiB, and lytic polysaccharide monooxygenase LPMO10. Both ChiA and ChiB contain two CBM50 binding domains and one catalytic domain, whereas LPMO10 includes a signal peptide and a single catalytic domain. The chitinases ChiA, its truncated variant ChiA2, and ChiB were heterologously expressed in Escherichia coli. The purified enzymes efficiently degraded colloidal chitin and inhibited the spore germination of Penicillium digitatum. Notably, even after losing one CBM50 domain, the resultant enzyme, consisting of the remaining CBM50 domain and the catalytic domain, maintained its colloidal chitin hydrolysis and antifungal activity, indicating commendable stability. These results underscore the role of B. velezensis chitinases in suppressing plant pathogenic fungi and provide a solid foundation for developing and applying chitinase-based biocontrol strategies.

Analysis of host factor networks during hepatitis B virus infection in primary human hepatocytes.

BACKGROUND: Chronic hepatitis B virus (HBV) infection affects around 250 million people worldwide, causing approximately 887,000 deaths annually, primarily owing to cirrhosis and hepatocellular carcinoma (HCC). The current approved treatments for chronic HBV infection, such as interferon and nucleos(t)ide analogs, have certain limitations as they cannot completely eradicate covalently closed circular DNA (cccDNA). Considering that HBV replication relies on host transcription factors, focusing on host factors in the HBV genome may provide insights into new therapeutic targets against HBV. Therefore, understanding the mechanisms underlying viral persistence and hepatocyte pathogenesis, along with the associated host factors, is crucial. In this study, we investigated novel therapeutic targets for HBV infection by identifying gene and pathway networks involved in HBV replication in primary human hepatocytes (PHHs). Importantly, our study utilized cultured primary hepatocytes, allowing transcriptomic profiling in a biologically relevant context and enabling the investigation of early HBV-mediated effects. METHODS: PHHs were infected with HBV virion particles derived from HepAD38 cells at 80 HBV genome equivalents per cell (Geq/cell). For transcriptomic sequencing, PHHs were harvested 1, 2-, 3-, 5-, and 7 days post-infection (dpi). After preparing the libraries, clustering and sequencing were conducted to generate RNA-sequencing data. This data was processed using Bioinformatics tools and software to analyze DEGs and obtain statistically significant results. Furthermore, qRT-PCR was performed to validate the RNA-sequencing results, ensuring consistent findings. RESULTS: We observed significant alterations in the expression patterns of 149 genes from days 1 to 7 following HBV infection (R2 > 0.7, q < 0.05). Functional analysis of these genes identified RNA-binding proteins involved in mRNA metabolism and the regulation of alternative splicing during HBV infection. Results from qRT-PCR experiments and the analysis of two validation datasets suggest that RBM14 and RPL28 may serve as potential biomarkers for HBV-associated HCC. CONCLUSIONS: Transcriptome analysis of gene expression changes during HBV infection in PHHs provided valuable insights into chronic HBV infection. Additionally, understanding the functional involvement of host factor networks in the molecular mechanisms of HBV replication and transcription may facilitate the development of novel strategies for HBV treatment.

Novel quinolone substituted 1,3,4-oxadiazole derivatives: design, synthesis, antimicrobial and anti-inflammatory potential.

A novel series of quinolone-substituted 1,3,4-oxadiazole derivatives 4(a-l) have been designed and synthesized. The target compounds were investigated for their antibacterial activity against gram positive (Staphylococcus aureus, ATCC 25923, Enterococcus faecalis, ATCC 29212) and gram negative bacterium (Escherichia coli, ATCC 25922, Pseudomonas aeruginosa, ATCC 27853) for antifungal activity using (Candida albicans, ATCC 10231) and anti-inflammatory activity as COX-II inhibitors, respectively. The 1,3,4-oxadiazole functionality was introduced at C-6 position of pipemidic acid derivatives. IR, 1H NMR and Mass spectrometry techniques confirmed the structure of synthesized derivatives. The quinolone (pipemidic acid)-oxadiazole hybrid derivatives were effective against bacterial strains. When compared to ciprofloxacin (MIC 16 µg/mL), the compounds under consideration (4f, 4h, and 4k) showed significant antibacterial activity against all bacterial strains except Enterococcus faecalis, with MICs of 8 µg/mL. On the other hand, synthesized target compounds 4(a-l) did not respond well against Candida albicans fungal strain. The compound (4k) represents high % inhibition against COX-II. The compounds (4f, 4h and 4k) exhibited highest hydrogen bonding interaction with ARG57, ARG72, ARG78, LEU54 and MET16 target residues with a binding energy of - 8.4, - 8.6 and - 8.5 kcal/mol into the active pocket of DNA gyrase enzyme respectively even better in comparison to reference ligands. Based on the docking study, quinolone (pipemidic acid) oxadiazole hybrid structural ligands exhibited strong interaction at binding pockets of DNA gyrase enzyme.