Formation Ability Research Articles

Anti-Infective Bacteriophage Immobilized Nitric Oxide-Releasing Surface for Prevention of Thrombosis and Device-Associated Infections.

The treatment of critically ill patients has made great strides in the past few decades due to the rapid development of indwelling medical devices. Despite immense advancements in the design of these devices, indwelling medical device-associated infections and thrombosis are two major clinical problems that may lead to device failure and compromise clinical outcomes. Antibiotics are the current treatment choice for these infections; however, the global emergence of antibiotic-resistance and their biofilm formation abilities complicate the management of such infections. Moreover, systemic administration of anticoagulants has been used to counter medical device-induced thrombosis, but a range of serious adverse effects associated with all types of available anticoagulants entails exploring alternative options to counter device-associated thrombosis. In this study, bacteriophages (phages) were covalently immobilized on polydimethylsiloxane (PDMS) surface containing the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine (SNAP) via SNAP impregnation method. This dual strategy combines the targeted antibacterial activity of phages against bacterial pathogens with the antibacterial-antithrombotic activity of NO released from the polymeric surface. The PDMS, SNAP-PDMS, phage-immobilized PDMS (PDMS-Phage), and phage-immobilized SNAP-PDMS (SNAP-PDMS-Phage) surfaces were characterized for their surface topology, elemental composition, contact angle, SNAP loading, NO release and phage distribution. SNAP-PDMS and SNAP-PDMS-Phage surfaces showed similar and consistent NO release profiles over 24 h of incubation. Immobilization of whole phages on PDMS and SNAP-PDMS was achieved with densities of 2.4 ± 0.54 and 2.1 ± 0.33 phages μm-2, respectively. Immobilized phages were found to retain their activity, and SNAP-PDMS-Phage surfaces showed a significant reduction in planktonic (99.99 ± 0.08%) as well as adhered (99.80 ± 0.05%) Escherichia coli as compared to controls in log killing assays. The SNAP-PDMS-Phage surfaces also exhibited significantly reduced platelet adhesion by 64.65 ± 2.95% as compared to control PDMS surfaces. All fabricated surfaces were found to be nonhemolytic and do not exhibit any significant cytotoxic effects toward mammalian fibroblast cells. This study is the first of its kind to demonstrate the combinatorial pertinence of phages and NO to prevent antibiotic-resistant/sensitive bacterial infections and thrombosis associated with indwelling medical devices.

Modulation of virulence and metabolic profiles in Klebsiella pneumoniae under indole-mediated stress response

Indole, a crucial bacterial signaling molecule, plays a fundamental role in regulating various physiological processes within bacteria, including growth, acid tolerance, biofilm development, motility, and other cellular functions. Its regulatory influence extends beyond indole-producing bacteria, significantly impacting the physiological activities in non-indole-producing species. In this study, we demonstrate that indole enhances the pathogenicity and viability of Klebsiella pneumoniae using the Galleria mellonella infection model and serum killing assay. Concurrently, indole has varying effects on biofilm formation in K. pneumoniae, with some strains showing enhanced biofilm formation ability. To elucidate the underlying molecular mechanisms, transcriptome analysis revealed that indole exposure in K. pneumoniae led to the upregulation of genes associated with pili formation and iron acquisition systems, while simultaneously inducing oxidative stress responses. Additionally, our analysis uncovered extensive metabolic remodeling. Specifically, we observed significant upregulation of genes involved in simple carbohydrate utilization pathways, including those responsible for galactose, mannose, and maltose metabolism, as well as enhanced expression of genes associated with pyrimidine biosynthesis. These findings collectively indicate that indole enhances the intestinal colonization and pathogenicity of K. pneumoniae primarily by modulation of fimbriae expression and metabolic pathway regulation.

Implication of the novel microtubule targeting agent, AUS_001, in pancreatic cancer cellular signaling.

748 Background: Pancreatic cancer (PanCa) is considered a major therapeutic challenge due to its poor prognosis, high mortality rate and resistance to most therapies, underlining the need for new treatment approaches. Our previous investigations revealed that the prenylated hydroxy-stilbene, AUS_001, inhibits β-tubulin polymerization via its unique binding to the colchicine site of tubulin. A cell-based profiling platform identified sensitivity of 12 out of 13 PanCa lines to AUS_001 with a median concentration causing 50% growth inhibition of 0.227µM. The goal of the current study was to elucidate the signaling activity and cellular responses following treatment with AUS_001 and explore the prospect of the latter in PanCa treatment. Methods: A series of functional and biochemical assays were performed to delineate the effect of AUS_001 on the growth, colony formation ability, invasive capacity and oxidative status of PanCa cells. Tumor growth was evaluated in PANC-1 implanted CB.17 SCID mice and MIA PaCa-2 implanted nude mice upon intraperitoneal administration of AUS_001 once weekly. Metabolic profiling was carried out using the Seahorse XF Analyzer. RNA silencing and adenovirus-mediated overexpression of the Dominant-Negative Mutant of c-Jun were employed to explore the link of c-Jun activation and AUS_001-induced cytotoxicity. Results: The potential of AUS_001 to disrupt PanCa cell functions was established in vitro and in vivo . Viability and compromised membrane integrity were multiplexed and resulted in half maximal effective concentration agreement indicating drug-induced cytotoxicity. AUS_001-treated cells underwent apoptosis followed by secondary necrosis, exerted diminished anchorage-independent growth and metastatic potential in vitro . Importantly, tumor growth was significantly reduced in PanCa murine xenograft models by AUS_001 as a monotherapy. Pretreatment with N-acetyl-l-cysteine did not alter cellular sensitivity to AUS_001, suggesting that the time-dependent induction of reactive oxygen species upon AUS_001 exposure is not the primary cause of cytotoxicity. Notably, the oxygen consumption rate, extracellular acidification rate and function of all mitochondrial complexes (I-IV) of live MIA PaCa_2 cells were significantly impaired in both glucose- and galactose-containing media 48h after AUS_001 administration. Integration of transcriptomic and proteomic data originating from AUS_001-challenged cells uncovered the dramatic induction of c-Jun and FosB stress responders. Further studies demonstrated that c-Jun transcriptional activation acts as a partial mediator of AUS_001-induced cytotoxicity. Conclusions: Collectively, our findings provide critical insights into the molecular events triggered by AUS_001 in PanCa cells and serve as supporting data for future exploration of AUS_001 as a novel PanCa therapeutic agent.

Role of bio-chemical scale interactions in the Co-landfill of municipal solid waste and bottom ash.

Co-landfill of municipal solid waste (MSW) and bottom ash (BA) has accelerated the scaling of the leachate collection systems (LCS). The matrix of biofilm formation and mineral deposition makes the scaling process in LCS more complicated. However, the fate of metals released from BA and the role of microorganisms in the leachate, which determine the chemical and biological scaling, are not well understood; the scale adsorption ability is little discussed. We analyzed the microorganism response and scale properties under various simulated landfill conditions with different MSW to BA ratios. The adsorption ability of the scales was evaluated through ultrasonic treatment. Scale characterization revealed that Ca2+ plays different roles with co-landfilled BA. Under BA-only landfilling conditions, Ca2+ was precipitated as CaCO3, with a strong adsorption ability. The co-landfilling of BA and MSW resulted in the formation of a thicker scale compared to BA landfilling alone. Interestingly, the hydrophilic surface of the biofilm enhanced the descaling efficiency, achieving up to 85%. Microbial composition analysis at the genus level revealed that the co-landfilling with BA significantly influenced the microbial community. Particularly, BA enhanced the biofilm formation ability of the microorganisms. Additionally, the scales adhering to polyvinyl chloride (PVC) pipes developed a distinct microenvironment different from the leachate, with a noticeable increase in anaerobic bacteria. These findings offer new insights into scale control and pipeline failure caused by aging and corrosion.

CircICMT upregulates and suppresses the malignant behavior of bladder cancer.

Circular RNA (circRNA) is a new type of endogenous single-stranded RNA with a covalently closed circular structure. Increasing evidence shows that circRNA plays an important role in regulating gene expression in tumors. circICMT is a circular RNA produced by the ICMT gene. Currently, the molecular function of circICMT in bladder cancer remains unclear. Differentially expressed circRNAs were identified from RNA sequencing data and circICMT was identified as a new candidate circRNA. qRT-PCR and sanger sequencing were used to detect the expression of circICMT in bladder cancer tissue specimens. Stable cell lines overexpressing and knocking down circICMT were constructed to explore the effect of circICMT on bladder cancer cells. Its biological effects were detected through wound healing experiments, colony formation experiments, CCK-8 experiments and xenogeneic tumorigenesis experiments. This study found that circICMT was significantly upregulated in bladder cancer tissue specimens. Overexpression of circICMT can inhibit cell migration, proliferation and colony formation ability, while knockdown of circICMT promotes the malignant phenotype of bladder cancer cells. Bioinformatics predictions have found that circICMT can bind to a variety of miRNAs and RBPs and may form a complex regulatory network to regulate the progression of bladder cancer. circICMT is significantly highly expressed in bladder cancer, and intervening circICMT expression affects the malignant phenotype of bladder cancer cells in vivo and in vitro, which may provide potential biomarkers and therapeutic targets for the management of bladder cancer.

HTR1D regulates the PI3K/Akt signaling pathway to impact hepatocellular carcinoma development and resistance to sorafenib

BackgroundHepatocellular carcinoma (HCC) has a poor prognosis, partly due to resistance to treatments like sorafenib. The 5-hydroxytryptamine receptor 1D (HTR1D) is involved in cancer progression through the PI3K/Akt pathway, but its role in HCC is not well understood. This study investigates HTR1D’s expression, function, and potential as a prognostic marker in HCC.MethodsFirst, the correlation between HTR1D and hepatocellular carcinoma was analyzed using the TCGA database, and the expression level of HTR1D in clinical samples was detected by qPCR. Then the siRNA was transfected into Huh-7 and Hep3B cells, and the cell proliferation ability, colony formation ability, migration and invasion ability were detected with or without sorafenib. And the expression of the PI3K/Akt pathway was detected by Western Blot. Finally, the potential of HTR1D as a predictive marker for patient prognosis was evaluated by immunohistochemistry.ResultsAnalysis of TCGA data showed that methylation of the HTR1D gene was associated with cancer status. Clinical samples confirmed significant differences in HTR1D expression between HCC and adjacent tissues, with higher expression correlating with poorer patient prognosis. Interference with HTR1D gene expression demonstrated its role in promoting HCC proliferation, migration, and drug resistance through the PI3K/Akt pathway. These findings were validated in a mouse model. Immunohistochemical analysis of clinicopathological samples suggested that HTR1D could be a valuable prognostic marker for HCC.ConclusionHTR1D is highly expressed in hepatocellular carcinoma tissues, and it can influence hepatocellular carcinoma development and resistance to sorafenib by regulating the PI3K/Akt signaling pathway. In addition, HTR1D has potential as a prognostic indicator.

Targeted inhibition of PqsR in Pseudomonas aeruginosa PAO1 quorum-sensing network by chalcones as promising antibacterial compounds.

Pseudomonas aeruginosa's inherent and adapted resistance makes this pathogen a serious problem for antimicrobial treatments. Furthermore, its biofilm formation ability is the most critical armor against antimicrobial therapy, and the virulence factors, on the other hand, contribute to fatal infection and other recalcitrant phenotypic characteristics. These capabilities are harmonized through cell-cell communication called Quorum Sensing (QS), which results in gene expression regulation via three major interconnected circuits: las, rhl, and pqs system. Pqs circuit specificity in P. aeruginosa made this system an attractive target for antipseudomonal therapy. The current study focuses on novel chalcone derivatives that attenuate P. aeruginosa's pathogenicity by inhibiting the QS system. Chalcones are included in the flavonoid class of phenolic compounds. This family forms one of the greatest groups of bioactive natural products. The chalcone derivatives's potential activity against the QS system was evaluated through biofilm inhibition, decreased virulence factors production, and gene expression. Among all the tested compounds, 5H and NMe2 chalcone derivatives reduced biofilm formation by 60.9% and 78.9%, respectively, and virulence factors production, including pyocyanin (decreased by 5H 30.9% and NMe2 30.7%) and pyoverdine (decreased by 5H 47.1% and NMe2 56.9%) and the QS gene expression (LasR, RhlR, and PqsR) more effectively than other derivatives. These chalcone compounds can be used as a supplement besides antimicrobial chemotherapy to attenuate pseudomonas pathogenicity.

Epidemiological and molecular characteristics of extraintestinal pathogenic escherichia coli isolated from diseased cattle and sheep in Xinjiang, China from 2015 to 2019

Escherichia coli has become a common causative agent of infections in animals, inflicting serious economic losses on livestock production and posing a threat to public health. Escherichia coli infection is common and tends to be complex in Xinjiang, a major region of cattle and sheep breeding in China. This study aims to explore the current status and molecular characteristics of Escherichia coli infection in cattle and sheep in Xinjiang, as part of the disease prevention and control strategy. Herein we isolated Extraintestinal pathogenic Escherichia coli (ExPEC) from the liver, spleen, lung, heart, and lymph nodes of infected cattle and sheep (Xinjiang, China), and phylogenetic grouping, serotyping, and multilocus sequence typing were performed to determine epidemic and molecular characteristics. We also assessed their biofilm formation ability. A total of 132 strains of ExPEC were identified from diseased cattle and sheep, belonging to 7 phylogenetic groups. A and B1 are advantageous groups. Further, 22 serogroups were found, with O101 (26/132), O154 (14/132), and O65 (8/132) being the predominant ones. Among the seven sequence types identified by multilocus sequence typing, ST10 was the most common, followed by ST23 and ST457. Of 132, 105 (79.5%) strains were able to form biofilms: 15 strains (11.4%) were strong, 28 (21.2%) were medium, and 62 (47%) were weak biofilm producers. These findings will contribute to a better understanding of the molecular epidemiology of ExPEC in Xinjiang, China, and can be applied to the development, prevention, and disease control of future diagnostic tools and vaccine.

Genetic diversity and virulence of Bacillus cereus group isolates from bloodstream infections.

Bacillus cereus catheter-related bloodstream infections (CRBSIs) are an increasing concern in Japanese hospitals. Although their clinical characteristics have been explored, the genetic relationships and virulence profiles of B. cereus isolates from CRBSIs remain understudied. Here, using advanced genomic techniques, we investigated the genetic diversity, phylogenetic relationships, and virulence profiles of B. cereus isolates from patients with bloodstream infections. We analyzed 28 B. cereus group strains isolated from blood samples at the University of Tokyo Hospital between 2005 and 2017 using whole-genome sequencing, core-genome single-nucleotide polymorphism (SNP) typing, and virulence gene profiling. Core-genome SNP analysis revealed significant genetic diversity among the isolates, suggesting multiple independent sources of infection. The isolates predominantly belonged to panC clades III and IV, with distinct virulence gene profiles. All panC clade III isolates contained hbl operon genes, whereas four isolates from clade IV harbored cereulide synthetase genes (cesABCD). One isolate possessed a capsule gene operon (capBCADE), a rare finding among clinical B. cereus strains. Biofilm formation ability was observed in 50% of catheter-related isolates, although this ability was not significantly different from that of the noncatheter-related isolates.IMPORTANCEThis study provides novel insights into the genetic diversity and virulence potential of B. cereus strains causing bloodstream infections in a Japanese hospital setting. These findings suggest diverse infection pathways and highlight the importance of continuous molecular epidemiological surveillance for effective infection control.

Abstract A010: PARP1 selective inhibition sensitize triple-negative breast cancers to photon and alpha-particle therapy regardless of homologous recombination proficiency status

Abstract The association of Poly (ADP-ribose) polymerase (PARP) inhibitors with radiotherapy (RT) increase RT-induced DNA damage and radiosensitize tumors regardless deficiency in DNA repair pathways. Although PARP1 is the main protein responsible for PARP-mediated DNA repair, all first-generation PARP inhibitors act on both PARP1 and PARP2, which the latter is associated with hematological toxicity. The RT ability to induce DNA damage can be influenced by the radiation linear energy transfer (LET). High-LET radiation, such as alpha particles (LET: 60-200 keV/μm), induces more complex DNA damage than does low-LET radiation (photon, LET: 0.2 keV/μm). Thus, high-LET radiation combined with selective PARP1 inhibitors may be a promising strategy to radiosensitize tumors. The purpose of this study was to investigate if the selective PARP1 inhibition could radiosensitize BRCA1 mutant and wild-type triple-negative breast cancers (TNBC) to photons and alpha particles. The radiosensitization effect in vitro was assessed using TNBC cells: MDA-MB-436 (BRCA1 mutated), and its isogenic pair with BRCA1 recovered, MDA-MB-436 BRCA1, and 4T1. The IC50 of the PARP1 selective inhibitor (AZD5305) was determined across all cell lines by the clonogenic assay, and concentrations of AZD5305 that did not affect the colony formation ability without radiation were chosen for the radiopotentiation evaluation (clonogenic assay). Mice were inoculated with 4T1 cells in the hind leg. Diffusing Alpha-emitter Radiation Therapy (Alpha DaRT) was used to deliver alpha particles intratumorally, by the implantation of 224Ra-loaded sources. AZD5305 (1 mg/kg) was daily administered by oral gavage for 6 consecutive days, starting 24 h before Alpha DaRT implantation. Tumor growth delay and survival were assessed. AZD5305 significantly radiosensitized all the evaluated cell lines in vitro. AZD5305 alone (mice implanted with inert seeds) did not affect the tumor growth in mice (p=0.12) in comparison with inert+vehicle. Alpha DaRT delayed tumor growth in comparison with mice treated with inert+vehicle (p=0.03), but the Alpha DaRT+AZD5305 reduced tumor growth in comparison with Alpha DaRT+vehicle (p=0.05). Alpha DaRT promoted a non-significant (p=0.09) increase in survival when compared with inert+vehicle, but Alpha DaRT+AZD5305 increased survival in comparison with inert+vehicle (p=0.002), and Alpha DaRT+vehicle (p=0.06). Our findings demonstrate that AZD5305 significantly radiosensitizes TNBC to photons and alpha particles, regardless of the homologous recombination proficiency status. These results are novel because there no studies investigating selective PARP1 inhibition in combination with photons and alpha particles. Our work is relevant because the combination of AZD5305 with Alpha DaRT offers a promising strategy to minimize the adverse effects of PARP inhibition. AZD5305 presents less off-target effects than non-selective PARP inhibitors, while Alpha DaRT delivers alpha particles directly into the tumor, limiting radiosensitization of normal tissue. Citation Format: Poliana C. Marinello, Marco Tulio Freitas Reis, Walison Augusto Da Silva Brito, Amy Wu, Alexandre Rubinstein, Mark D. Wasley, Mandira Manandhar, Scott J. Bright, Yogesh Rai, Seyed Mojtaba Hosseini Ghahfarokhi, Ronen Segal, Vered Domankevich, Gabriel O. Sawakuchi. PARP1 selective inhibition sensitize triple-negative breast cancers to photon and alpha-particle therapy regardless of homologous recombination proficiency status. [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Targeted Therapies in Combination with Radiotherapy; 2025 Jan 26-29; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(2_Suppl):Abstract nr A010.

Anti-cancer activity of synthetic gefitinib-1,2,3-triazole derivatives against Hela cells via induction of apoptosis

Cervical cancer ranks as the fourth most common cancer among women. However, the current treatments have significant side effects and limited therapeutic effects on advanced diseases, so it is necessary to discover better treatments for cervical cancer. The current study investigated the potential anticancer effects of a series of gefitinib-1,2,3-triazole derivative on Hela cells. Among the investigated, the target compound c13 showed good anticancer activity against Hela cells (IC50 = 5.66 ± 0.35 μM) compared with gefitinib (IC50 = 14.18 ± 3.19 μM). Moreover, compound c13 significantly inhibited the colony formation ability of Hela cells in a dose-dependent manner, accompanied by morphological changes in HeLa cells. Further investigations demonstrated that compound c13 triggered cell apoptosis and arrested the cell cycle at the G2/M phase in Hela cells. In addition, western blot analysis revealed that compound c13 upregulated the Bax/Bcl-2 ratio, and increased the levels of active caspase 3 and PARP1 cleavage, which suggested the involvement of the mitochondrial pathway in compound c13-induced apoptosis. In brief, these results indicated that compound c13 is a promising compound for the treatment of cervical cancer.

Effect of Bovine Serum on Quorum Sensing Genes Expression in MDR Resistant P. Aeruginosa

Background: Pseudomonas aeruginosa, similar to several bacteria, use chemical signals for intercellular communication via use of quorum sensing (QS) mechanisms. QS enable the bacteria groups to detect population density and, in reaction to variations in cell density, to synchronize their behaviors. The current study intended to investigatethe effectof bovine serum on quorum sensing genes expression in Pseudomonas aeruginosaduring early stages of growth. Methodology: Pseudomonas aeruginosa isolates were obtained from burns, wounds, urine, and ears. Bacteria isolates were identified in accordance to their biochemical reactions, then antibiotic susceptibility and The isolates' ability to build biofilms was examined, and each bacterial isolate's genomic DNA was extracted in order to find quorum sensing genes (rhlR, rhlI, lasR, and lasI). Result: From different clinicalspecimens, twenty-five Pseudomonas aeruginosa isolates were identified,antibiotic resistance was present in these isolates., and it was found that only 10(40%) of these isolates were biofilm producers. Biofilm virulence genes lasR, lasI, rhlR, and rhlI were detected in all Pseudomonas aeruginosa isolates examined. Conclusion: lasR, lasI, rhlR, and rhlI genes were common inPseudomonas aeruginosa isolates that have high rate of resistance to all antibiotics, and strong ability in biofilm formation.

Quinacrine Inhibits Hepatocellular Carcinoma Growth and Enhances the Anti-HCC Effects of Lenvatinib.

Hepatocellular Carcinoma (HCC) is a highly prevalent cancer worldwide, necessitating effective treatment options. However, current treatments do not provide satisfactory results. Quinacrine, a synthetic drug belonging to the 9-aminoacridine family, has demonstrated promising antitumor effects. The objective of the current study is to evaluate the anti-HCC effect of Quinacrine and explore whether quinacrine can improve the anti-HCC response of lenvatinib in vitro and in vivo. The HepG2 and MHCC-97H cells were treated with Quinacrine. Cell proliferation and cell apoptosis were assessed using the Cell Counting Kit-8 (CCK8) Assay, Colony Formation Assay, and Annexin V/7-AAD staining method. The invasion and migratory ability of HepG2 and MHCC-97H cells were assessed by Transwell Assay. The level of ROS of HCC cells was measured using a ROS-kit by Flow cytometric analysis. Besides, an in vivo study was performed in the Balb/c nude mice bearing MHCC-97H tumors to analyze the function of Quinacrine in tumor growth. Quinacrine can decrease cell viability in HepG2 and MHCC-97H cells, but not affect LO2 cells. Quinacrine impaired the colony formation, invasion and migratory ability in half-maximal inhibitory concentration (IC50). Quinacrine also significantly induced apoptosis in HepG2 and MHCC-97H cells in a concentrationdependent manner. On the one hand, ROS was significantly up-regulated in HCC cells after quinacrine treatment. On the other hand, We found quinacrine blocked autophagy flux in HepG2 and MHCC-97H cells. Moreover, Quinacrine significantly enhances the anti-HCC efficacy of lenvatinib in vitro. In the mouse MHCC-97H model, We found that combination therapy with Quinacrine and lenvatinib resulted in a smaller tumor volume and weight than inoculated with lenvatinib alone. Our findings demonstrated that quinacrine exerts anti-HCC effects and sensitizes hepatocellular carcinoma to lenvatinib. Collectively, our study provides novel therapeutic insights for managing HCC and offers a valuable strategy for future clinical interventions in this field.

Combined Analysis of Transcriptomes and Metabolomes Reveals Key Genes and Substances That Affect the Formation of a Multi-Species Biofilm by Nine Gut Bacteria

Biofilms are one of the ways microorganisms exist in natural environments. In recent years, research has gradually shifted its focus to exploring the complexity and interactions of multi-species biofilms. A study showed that nine gut bacteria can form a multi-species biofilm on wheat fibers (M9 biofilm). However, the previous study did not clarify the reasons why M9 exhibited a better biofilm formation ability than the mono-species biofilms. In this study, the gene expression levels and metabolic accumulation of the M9 multi-species biofilm and biofilms of each individual bacterium were analyzed using transcriptomes and metabolomes. The differentially expressed genes (DEGs) showed that there were 740 common DEGs that existed in all of the nine groups, and they could regulate five pathways related to bacterial motility, cellular communication, and signal transduction. The metabolome results revealed that many peptides/amino acids and derivatives were produced in the M9 biofilm. Furthermore, purine metabolism was significantly enhanced in the M9 biofilm. L-arginine, l-serine, guanosine, and hypoxanthine were the common differentially accumulated metabolites (DAMs). The combined analysis of the transcriptomes and metabolomes showed that there were 26 common DEGs highly correlated with the four common DAMs, and they were involved in five metabolic pathways related to amino acids and purines. These results indicate that M9 can regulate multi-species biofilm formation by modulating genes related to bacterial motility, cellular communication, signal transduction, and the metabolism of amino acids and purines. This study provides insights into the interactions of microbial biofilms.

Identification of KRT16 and ANXA10 as cell cycle regulation genes for lung adenocarcinoma based on self-transcriptome sequencing of surgical samples and TCGA public data mining

AimThis study aimed to identify the genes associated with the development of lung adenocarcinoma (LUAD) and potential therapeutic targets.MethodsDifferentially expressed genes (DEGs) were identified by self-transcriptome sequencing of tumor tissues and paracancerous tissues resected during surgery and combined with The Cancer Genome Atlas (TCGA) data to screen for the genes associated with LUAD prognosis. The expression was validated at mRNA and protein levels, and the gene knockdown was used to examine the impact and underlying mechanisms on lung cancer cells.ResultsA total of 227 DEGs were identified by transcriptome sequencing, and the 20 DEGs with the most significant differences were used for co-analysis with TCGA data. The findings suggested that KRT16 and ANXA10 might have an important role in the development of LUAD after validating the mRNA and protein expression levels at the cellular level. The knockdown of KRT16 and ANXA10 inhibited the proliferation of lung cancer cells, and the cell cycle was blocked in the G1 phase. The expression of the G1/S–phase cell cycle checkpoint–related proteins cyclin D1 and cyclin E was inhibited by KRT16 and ANXA10 knockdown, respectively. The tumor formation ability decreased after KRT16 or ANXA10 knockdown in vivo.ConclusionsKRT16 and ANXA10 are potential genes regulating the development of LUAD. Also, they may be potential targets for the targeted therapy of LUAD by inhibiting the proliferation of lung cancer cells and blocking the cell cycle by affecting key protein expression levels at cell cycle checkpoints.

Inhibiting miR-155-5p promotes proliferation of human submandibular gland epithelial cells in primary Sjogren's syndrome by negatively regulating the PI3K/AKT signaling pathway via PIK3R1.

To investigate the mechanism mediating the regulatory effect of miR-155-5p on proliferation of human submandibular gland epithelial cells (HSGECs) in primary Sjogren's syndrome (pSS). Dual luciferase reporter assay was used to verify the targeting relationship between miR-155-5p and the PI3K/AKT pathway. In a HSGEC model of pSS induced by simulation with TRAIL and INF-γ, the effects of miR-155-inhibitor-NC or miR-155 inhibitor on cell viability, cell cycle, apoptosis and proliferation were evaluated using CKK8 assay, flow cytometry and colony formation assay. ELISA and RT-PCR were used to detect the expressions of inflammatory cytokines and miR-155-5p mRNA in the cells; Western blotting was performed to detect the expressions of proteins in the PI3K/AKT signaling pathway. Dual luciferase assay showed that miR-155-5p targets the PI3K/AKT pathway via PIK3R1 mRNA. The HSGEC model of pSS showed significantly decreased cell viability, cell clone formation ability and expressions IL-10 and IL-4 and increased cell apoptosis, cell percentage in G2 phase, expressions of TNF‑α, IL-6, miR-155-5p and PIK3R1 mRNA, p-PI3K/PI3K ratio, p-Akt/AKT ratio, and PIK3R1 protein expression. Treatment of the cell models with miR-155 inhibitor significantly increased the cell viability, G1 phase cell percentage, colony formation ability, and expressions of IL-10 and IL-4 levels, and obviously reduced cell apoptosis rate, G2 phase cell percentage, expressions of TNF-α, IL-6, miR-155-5p and PIK3R1 mRNA, p-PI3K/PI3K ratio, p-AKT/AKT ratio, and PIK3R1 protein expression. In HSGEC model of pSS, inhibition of miR-155-5p can promote cell proliferation and reduced cell apoptosis by targeting PI3K1 mRNA to negatively regulate the overexpression of PI3K/AKT signaling pathway.

Functional analysis of the type II toxin-antitoxin system ParDE in Streptococcus suis serotype 2

Streptococcus suis (S. suis) is a major pathogen in swine and poses a potential zoonotic threat, which may cause serious diseases. Many toxin-antitoxin (TA) systems have been discovered in S. suis, but their functions have not yet been fully elucidated. In this study, an auto-regulating type II TA system, ParDE, was identified in S. suis serotype 2 strain ZY05719. We constructed a mutant strain, ΔparDE, to explore its functions in bacterial virulence, various stress responses, and biofilm formation capabilities. The toxicity exerted by the toxin ParE can be neutralized by the antitoxin ParD. The β-galactosidase activity analysis indicated that ParDE has an autoregulatory function. An electrophoretic mobility shift assay (EMSA) confirmed that the antitoxin ParD bound to the promoter of ParDE as dimers. In the mouse infection model, the deletion of ParDE in ZY05719 significantly attenuated virulence. ΔparDE also exhibited a reduced anti-oxidative stress ability, and ΔparDE was more susceptible to phagocytosis and killing by macrophages. Moreover, the biofilm formation ability of the ΔparDE strain was significantly enhanced compared to ZY05719. Taken together, these findings indicate that the type II TA system ParDE plays a significant role in the pathogenesis of S. suis, providing new insights into its pathogenic mechanisms.

SRNA113 regulates Pseudomonas plecoglossicida motility to affect immune response against infection in pearl gentian grouper.

Small RNAs (sRNAs) are a class of molecules capable of perceiving environmental changes and exerting post-transcriptional regulation over target gene expression, thereby influencing bacterial virulence and host immune responses. Pseudomonas plecoglossicida is a pathogenic bacterium that poses a significant threat to aquatic animal health. However, the regulatory mechanisms of sRNAs in P. plecoglossicida remain unclear. This study focused on sRNA113, previously identified as a potential regulator of the fliP gene, a key component of the lateral flagellar type III secretion system. To investigate the effects of sRNA113 on P. plecoglossicida virulence, as well as its role in regulating pathogenic processes and host immune responses, mutant strains lacking this sRNA were generated and analyzed. Deletion of sRNA113 resulted in the up-regulation of lateral flagellar type III secretion system-related genes in P. plecoglossicida, which enhanced bacterial swarming motility, biofilm formation, and chemotaxis ability in vitro. In vivo infection experiments with pearl gentian grouper revealed that sRNA113 deletion enhanced the pathogenicity of P. plecoglossicida. This heightened virulence was attributed to the up-regulation of genes associated with the lateral flagellar type III secretion system, resulting in higher bacterial loads within host tissues. This amplification of pathogenic activity intensified tissue damage, disrupted immune responses, and impaired the ability of the host to clear infection, ultimately leading to mortality. These findings underscore the critical role of sRNA113 in regulating the virulence of P. plecoglossicida and its interaction with host immune defenses. This study provides a foundation for further exploration of sRNA-mediated mechanisms in bacterial pathogenesis and host-pathogen interactions, contributing to a deeper understanding of virulence regulation and immune evasion in aquatic pathogens.

Newly identified c-di-GMP pathway putative EAL domain gene STM0343 regulates stress resistance and virulence in Salmonella enterica serovar Typhimurium

S. Typhimurium is a significant zoonotic pathogen, and its survival and transmission rely on stress resistance and virulence factors. Therefore, identifying key regulatory elements is crucial for preventing and controlling S. Typhimurium. We performed transcriptomic analysis and screened for a c-di-GMP pathway key gene STM0343, a putative EAL domain protein with an unknown function. Our findings revealed that the deletion of this gene (269ΔSTM0343) led to a 29.85% increase in c-di-GMP. In terms of stress resistance, the strain 269ΔSTM0343 showed significant improvements compared to the wild strain WT269. Specifically, it exhibited increases of 95.74% in extracellular protein and 35.96% in exopolysaccharide production by upregulating the expression of relevant genes. As a result, the biofilm formation ability of 269ΔSTM0343 was enhanced by 21.54%, accompanied by a more pronounced red, dry, and rough colony morphology. 269ΔSTM0343 also showed a 19.03% decrease in motility due to the downregulation of flhD expression. As a result, 269ΔSTM0343 increased resistance to various antibiotics, as well as to acidic conditions, oxidative stress, and disinfectants. In terms of virulence, compared to WT269, the adhesion and invasive ability of 269ΔSTM0343 to HeLa cells was enhanced by onefold and 25.67%, respectively. In in vivo experiments, mice challenged with 269ΔSTM0343 experienced greater weight loss, and the bacterial loads in the spleen, liver, and intestines were elevated by fivefold, 30-fold, and 21-fold, respectively, accompanied by more severe pathological damage. Mechanistic studies revealed that the adhesion and invasion capacities of 269ΔSTM0343ΔCsgB decreased by 29.41% and 68.58%, respectively, compared to 269ΔSTM0343. Additionally, LacZ gene reporting indicated that STM0343 inhibited the expression of CsgB. This suggests that STM0343 suppresses virulence by downregulating CsgB expression. This study provides insights into the regulatory mechanisms by which STM0343 reduces the stress resistance and pathogenicity of S. Typhimurium.

Supramolecular Gelation Based on Native Amino Acid Tyrosine and Its Charge-Transfer Complex Formation.

Self-assembly of amino acids and short-peptide derivatives attracted significant curiosity worldwide due to their unique self-assembly process and wide variety of applications. Amino acid is considered one of the important synthons in supramolecular chemistry. Self-assembly processes and applications of unfunctionalized native amino acids have been less reported in the literature. In this article, we are first-time reporting the self-assembly process of tyrosine (Tyr), an aromatic amino acid, in dimethyl sulfoxide (DMSO) solvent. Most of the studies related to Tyr self-assembly were reported in different aqueous solutions. In our work, we studied the self-assembly in several common organic solvents and found that Tyr could self-assemble into a supramolecular gel in dimethyl sulfoxide (DMSO) solvent. The self-assembly process was investigated by several techniques, such as UV-vis, fluorescence, FTIR, and NMR spectroscopy. Morphological features on the nanoscale were investigated through scanning electron microscopy (SEM). SEM images indicated the formation of nanofibrils with high aspect ratios. The supramolecular gel property was investigated by different rheological experiments. Computational study on the self-assembly process of Tyr in DMSO medium suggested that noncovalent interactions like hydrogen bonding and π-π stacking among the Tyr molecules played a prominent role. Finally, the charge-transfer complex formation ability of electron-rich Tyr with electron-deficient 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was studied. In the presence of DDQ due to the charge-transfer complex formation, the supramolecular gel converted into a reddish color solution, and their fibrillar nanoscale morphologies collapsed.