Microbial cell-type-based grouping model as a potential indicator of cervicovaginal flora prone to biofilm formation

Cervicovaginal (CV) microbiota is critical for the well-being of host. We investigated the relationship between the ratio of Lactobacilli (LB) and cocci/coccobacilli (C/CB)-type microbial cells with biofilm formation of CV mixed cultures of women with no inflammation/infection or any epithelial abnormalities in Pap-stained smears Group 1 (G1) corresponds to the flora with LB-type cells alone, whereas G2 corresponds to the LB-dominated flora. G3 contains balanced LB and C/CB cells and G4 is dominated with C/CB. G5 corresponds to a flora with C/CB-type cells alone. Biofilm formation of CV mixed cultures was assessed by crystal violet binding assay and optical density (OD)≥0.8 were defined as biofilm producers. G1 and G3 exist in higher frequencies compared to the other smear groups. However, although the frequency of G5 dominated with C/CB-type cells were the lowest (4%); biofilm formation in that group was observed in the highest frequency (42.9%). The least biofilm formation frequency was observed in G3 smears with balanced flora (1%). Biofilm formation in healthy CV flora increases when there becomes an imbalance between LB and C/CB-type cells and an increase in C/CB-type cells. Our approach may enable early detection of vaginal dysbiosis in healthy flora prone to biofilm-associated CV infections such as bacterial vaginosis (BV).

Antimicrobial Peptides: A Promising Alternative to Conventional Antimicrobials for Combating Polymicrobial Biofilms

Polymicrobial biofilms adhere to surfaces and enhance pathogen resistance to conventional treatments, significantly contributing to chronic infections in the respiratory tract, oral cavity, chronic wounds, and on medical devices. This review examines antimicrobial peptides (AMPs) as a promising alternative to traditional antibiotics for treating biofilm-associated infections. AMPs, which can be produced as part of the innate immune response or synthesized therapeutically, have broad-spectrum antimicrobial activity, often disrupting microbial cell membranes and causing cell death. Many specifically target negatively charged bacterial membranes, unlike host cell membranes. Research shows AMPs effectively inhibit and disrupt polymicrobial biofilms and can enhance conventional antibiotics' efficacy. Preclinical and clinical research is advancing, with animal studies and clinical trials showing promise against multidrug-resistant bacteria and fungi. Numerous patents indicate increasing interest in AMPs. However, challenges such as peptide stability, potential cytotoxicity, and high production costs must be addressed. Ongoing research focuses on optimizing AMP structures, enhancing stability, and developing cost-effective production methods. In summary, AMPs offer a novel approach to combating biofilm-associated infections, with their unique mechanisms and synergistic potential with existing antibiotics positioning them as promising candidates for future treatments.

Restoration of sperm quality in lead acetate-induced rats via treatment with Moringa oleifera leaf extract

Background

Lead intoxication triggers testicular toxicity via oxidative stress.

Aim

This study aimed to explore the antioxidant potential of Moringa oleifera leaf extract (MOLE) in enhancing the semen quality of rats exposed to lead acetate.

Methods

Twenty-five healthy rats were randomly and equally divided into five groups. Group C served as the negative control, whereas group C+ was exposed to lead acetate at 50-mg/kg body weight (BW)/day without MOLE. The T1, T2, and T3 groups were exposed to lead acetate at 50-mg/kg BW and concurrently received MOLE at doses of 200-, 316-, and 500-mg/kg BW/day, respectively, for 20 days. On the 21st day, all rats were euthanized for blood collection and testicle harvesting.

Results

The result showed that exposure to lead acetate at 50-mg/kg BW/day in group C+ led to significant decreases (p < 0.05) in superoxide dismutase (SOD) levels, plasma membrane integrity, Leydig and Sertoli cell counts, spermatozoa numbers, sperm motility, and live spermatozoa, as well as significant increases (p < 0.05) in malondialdehyde levels and apoptotic and necrotic sperm, compared with control group C-. The administration of MOLE to rats exposed to lead acetate resulted in improvement in all of these variables. However, SOD and testosterone levels, as well as spermatozoa numbers, viability, apoptosis, and necrosis, did not recover in group T3 (p < 0.05) compared with control group C-.

Conclusion

MOLE effectively restores sperm quality in lead acetate-induced rats.

Dhvar5- and MSI78-coated titanium are bactericidal against methicillin-resistant Staphylococcus aureus, immunomodulatory and osteogenic

Infection is one of the major issues associated with the failure of orthopedic devices, mainly due to implant bacterial colonization, biofilm formation, and associated antibiotic resistance. Antimicrobial peptides (AMP) are a promising alternative to conventional antibiotics given their broad-spectrum of activity, low propensity to induce bacterial resistance, and ability to modulate host immune responses. Dhvar5 (LLLFLLKKRKKRKY) and MSI78 (GIGKFLKKAKKFGKAFVKILKK) are two AMP with broad-spectrum activity against bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), one of the most problematic etiologic agents in Orthopedic Devices-Related Infections (ODRI). This work aims to evaluate the bactericidal, immunomodulatory and osteogenic potential of Dhvar5- and MSI78-coated titanium surfaces (AMP-Ti). Two AMP-Ti surfaces were successfully obtained by grafting Dhvar5 (0.8 ± 0.1 µM/mm2) or MSI78 (0.5 ± 0.3 µM/mm2) onto titanium substrates through a polydopamine layer. Both AMP-Ti were bactericidal against MRSA, eradicating bacteria upon contact for 6 h in a culture medium supplemented with human plasma proteins. The AMP-Ti immunomodulatory potential was evaluated using human primary macrophages, by assessing surfaces capacity to induce pro-/anti-inflammatory (M1/M2) markers and cytokines. While in naïve conditions both AMP-Ti surfaces slightly promoted the M2 marker CD163, in response to LPS and IFN-γ (simulating a bacterial infection), both AMP increased the M1 marker CCR7 and enhanced macrophage secretion of pro-inflammatory IL-6 and TNF-α cytokines, particularly for Ti-MSI78 surfaces. Additionally, both AMP-Ti surfaces were cytocompatible and promoted osteoblastic cell differentiation. This proof-of-concept study demonstrated the high potential of Dhvar5- and MSI78-Ti as antimicrobial coatings for ODRI prevention. STATEMENT OF SIGNIFICANCE: This study investigates the bactericidal effects of the antimicrobial peptides Dhvar5 and MSI78, immobilized on titanium (Ti) surfaces through a polydopamine coating, aiming at the prevention of Orthopedic-Device Related Infections (ODRIs). The developed coatings displayed MRSA-sterilizing activity, while revealing an immunomodulatory potential towards macrophages and promoting osteoblastic cell differentiation. This strategy allows a quick and easy immobilization of high quantities of AMP, unlike most other approaches, thus favoring its clinical translation.

Korean Red ginseng enhances ZBP1-mediated cell death to suppress viral protein expression in host defense against Influenza A virus

Korean Red ginseng has emerged as a potent candidate in the fight against various viral infections, demonstrating significant efficacy both in vitro and in vivo, particularly against influenza A viruses. Despite substantial evidence of its antiviral properties, the detailed molecular mechanisms through which it reduces viral lethality remain insufficiently understood. Our investigations have highlighted the superior effectiveness of Korean Red ginseng against influenza viruses, outperforming its effects on numerous other viral strains. We aim to uncover the specific mechanisms by which Korean Red ginseng exerts its antiviral effects, focusing on influenza A viruses. Our prior studies have identified the role of Z-DNA-binding protein 1 (ZBP1), a signaling complex involved in inducing programmed cell death in response to influenza virus infection. Given the critical role of ZBP1 as a sensor for viral nucleic acid, we hypothesize that Korean Red ginseng may modulate the ZBP1-derived cell death pathway. This interaction is anticipated to enhance cell death while concurrently suppressing viral protein expression, offering novel insights into the antiviral mechanism of Korean Red ginseng against influenza A viruses.

Advances and challenges in preparing membrane proteins for native mass spectrometry

Native mass spectrometry (nMS) is becoming a crucial tool for analyzing membrane proteins (MPs), yet challenges remain in solubilizing and stabilizing their native conformations while resolving and characterizing the heterogeneity introduced by post-translational modifications and ligand binding. This review highlights recent advancements and persistent challenges in preparing MPs for nMS. Optimizing detergents and additives can significantly reduce sample heterogeneity and surface charge, enhancing MP signal quality and structural preservation in nMS. A strategic workflow incorporating affinity capture, stabilization agents, and size-exclusion chromatography to remove unfolded species demonstrates success in improving nMS characterization. Continued development of customized detergents and reagents tailored for specific MPs may further minimize heterogeneity and boost signals. Instrumental advances are also needed to elucidate more dynamically complex and labile MPs. Effective sample preparation workflows may provide insights into MP structures, dynamics, and interactions underpinning membrane biology. With ongoing methodological innovation, nMS shows promise to complement biophysical studies and facilitate drug discovery targeting this clinically important yet technically demanding protein class.

Ambient fine particulate matter provokes multiple modalities of cell death via perturbation of subcellular structures

Fine particulate matter (PM2.5) is increasingly recognized for its detrimental effects on human health, with substantial evidence linking exposure to various forms of cell death and dysfunction across multiple organ systems. This review examines key cell death mechanisms triggered by PM2.5, including PANoptosis, necroptosis, autophagy, and ferroptosis, while other forms such as oncosis, paraptosis, and cuprotosis remain unreported in relation to PM2.5 exposure. Mitochondria, endoplasmic reticulum, and lysosomes emerge as pivotal organelles in the disruption of cellular homeostasis, with mitochondrial dysfunction particularly implicated in metabolic dysregulation and the activation of pro-apoptotic pathways. Although PM2.5 primarily affects the nucleus, cytoskeleton, mitochondria, endoplasmic reticulum, and lysosomes, other organelles like ribosomes, Golgi apparatus, and peroxisomes have received limited attention. Interactions between these organelles, such as endoplasmic reticulum-associated mitochondrial membranes, lysosome-associated mitophagy, and mitochondria-nuclei retro-signaling may significantly contribute to the cytotoxic effects of PM2.5. The mechanisms of PM2.5 toxicity, encompassing oxidative stress, inflammatory responses, and metabolic imbalances, are described in detail. Notably, PM2.5 activates the NLRP3 inflammasome, amplifying inflammatory responses and contributing to chronic diseases. Furthermore, PM2.5 exposure disrupts genetic and epigenetic regulation, often resulting in cell cycle arrest and exacerbating cellular damage. The composition, concentration, and seasonal variability of PM2.5 modulate these effects, underscoring the complexity of PM2.5-induced cellular dysfunction. Despite significant advances in understanding these pathways, further research is required to elucidate the long-term effects of chronic PM2.5 exposure, the role of epigenetic regulation, and potential strategies to mitigate its harmful impact on human health.

Targeting MurG enzyme in Klebsiella pneumoniae: An in silico approach to novel antimicrobial discovery

Antibiotic resistance poses a global crisis fuelled by widespread antibiotic use, particularly against Gram-negative bacteria like Klebsiella pneumoniae, a leading cause of hospital-acquired infections with high mortality rates. Urgent identification of effective drug targets is imperative, with a focus on metabolic pathways to inhibit bacterial growth. Targeting the crucial metabolic pathways of K. pneumoniae would be a more efficient way to prevent its growth and the diseases that it causes. The present study focused on inhibiting the UDP-N-acetylglucosamine--N-acetylmuramyl-(pentapeptide)pyrophosphoryl-undecaprenol N-acetylglucosamine transferase (MurG) enzyme, which is a key enzyme in peptidoglycan biosynthesis pathway. A high throughput virtual screening was used to find possible lead molecules from Enamine -High-Throughput Screening Center library. The resulting high binding affinity ligands were further assessed for their drug-likeness and other pharmacokinetic properties. Based on these analyses, the three ligands Z95813755_1, Z324718246_1 and Z324718246_2 were selected for further molecular dynamic simulation studies. The molecular dynamic simulation results and MM/PBSA analysis predicted that both Z95813755_1 and Z324718246_2, molecules show higher binding affinity towards MurG. For the first time we are reporting potential candidate inhibitors against MurG from K. pneumoniae, providing new insights in management of multi drug resistant K. pneumoniae infections.

siRNA-based therapy for overcoming drug resistance in human solid tumours; molecular and immunological approaches

RNA interference (RNAi) is a primordial biological process that protects against external intrusion. SiRNA has the potential to selectively silence disease-related genes in a sequence-specific way, thus offering a promising therapeutic approach. The efficacy of siRNA-based therapies in cancer treatment has gained significant recognition due to multiple studies demonstrating its ability to effectively suppress cancer cells' growth and multiplication. Moreover, siRNA-based medicines have shown considerable promise in enhancing the sensitivity of cancer cells to chemotherapy and other treatment methods by suppressing genes that play a role in the development of drug resistance. Exploring and identifying functional genes linked to cancer cell characteristics and drug resistance is crucial for developing effective siRNAs for cancer treatment and advancing targeted and personalized therapeutics. Targeting and silencing genes in charge of resistance mechanisms, such as those involved in drug efflux, cell survival, or DNA repair, is possible with siRNA therapy in the context of drug resistance, especially cancer. Through inhibiting these genes, siRNA therapy can prevent resistance and restore the efficacy of traditional medications. This review addresses the potential of siRNAs in addressing drug resistance in human tumours, opening up new possibilities in cancer therapy. This review article offers a non-systematic summary of how different siRNA types contribute to cancer cells' treatment resistance. Using pertinent keywords, sources were chosen from reliable databases, including PubMed, Scopus, and Google Scholar. The review covered essential papers in this area and those that mainly addressed the function of siRNA in drug resistance. The articles examined in connection with the title of this review were primarily published from 2020 onward and are based on in vitro studies. Furthermore, this article examines the potential barriers and prospective perspectives of siRNA therapies.

Necroptosis contributes to deoxynivalenol-induced activation of the hypothalamic-pituitary-adrenal axis in a piglet model

The mycotoxin deoxynivalenol (DON) is highly prevalent in cereals as an immune stressor. The hypothalamic-pituitary-adrenal (HPA) axis is activated during periods of stress, and the organism is accompanied by inflammation. Necroptosis is a newly identified type of cell death. However, the relationship between necroptosis and HPA axis activation induced by DON is rarely reported. Our study aimed to explore the role played by necroptosis in HPA activation in a stress of piglet model produced by DON. Our results indicated that both feeding with a contaminated-DON diet (4 ppm) and DON injection at 0.8 mg/kg BW increased the concentration of plasma corticotropin-releasing hormone (CRH) and adrenocorticotrophic hormone (ACTH) and the mRNA expression of adrenal steroidogenic acute regulatory protein (StAR). Furthermore, the mRNA expression of pro-inflammatory cytokines and factors related to necroptosis in the hypothalamus, pituitary gland, and adrenal gland were increased. As an inhibitor of necroptosis, necrostatin-1 (Nec-1) inhibited necroptosis through decreasing mRNA expression of necroptosis signal factors in the HPA axis. Nec-1 also reduced the mRNA levels of pro-inflammatory cytokines in the HPA axis. Meanwhile, the activation of the HPA axis was inhibited by Nec-1 as shown by the decrease of plasma CRH and ACTH concentrations and the mRNA expressions of hypothalamus CRH and pituitary POMC. These findings indicated that as a result of necroptosis, the HPA axis was activated by DON. In light of these findings, necroptosis could be considered as an intervention target that alleviates HPA axis activation and stress responses.

Types of cell death in diabetic cardiomyopathy: insights from animal models

Approximately one-tenth of the global population is affected by diabetes mellitus, and its incidence continues to rise each year. In China, 1.4 million patients die of diabetes-related complications every year. Additionally, approximately 26% of patients with diabetes develop diabetic cardiomyopathy, with heart failure being one of the main causes of death in these patients. However, early detection of diabetic cardiomyopathy has proven to be difficult in a clinical setting; furthermore, there are limited guidelines and targeted means of prevention and treatment for this disease. In recent years, several studies have provided evidence for the occurrence of various forms of regulated cell death in diabetic myocardial cells, including apoptosis, necroptosis, ferroptosis, and cuproptosis, which are closely linked to the pathological progression of diabetic cardiomyopathy. Although most research on diabetic cardiomyopathy is currently in the animal trial phase, the inhibition of these regulatory cell death processes can limit or slow down the progression of diabetic cardiomyopathy. Therefore, this review discusses the appropriate animal experimental models currently available for diabetic cardiomyopathy and evaluates the roles of apoptosis, necroptosis, ferroptosis, and cuproptosis in diabetic cardiomyopathy. We hope to provide new methods and ideas for future research in diabetic cardiomyopathy.

Methods and Models for Studying Mycobacterium tuberculosis in Respiratory Infections

Respiratory infections, including tuberculosis, constitute a major global health challenge. Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains one of the leading causes of mortality worldwide. The disease's complexity is attributed to Mtb's capacity to persist in latent states, evade host immune defenses, and develop resistance to antimicrobial treatments, posing significant challenges for diagnosis and therapy. Traditional models, such as animal studies and two-dimensional (2D) in vitro systems, often fail to accurately recapitulate human-specific immune processes, particularly the formation of granulomas-a defining feature of tubercular infection. These limitations underscore the need for more physiologically relevant models to study TB pathogenesis. Emerging three-dimensional (3D) in vitro systems, including organoids and lung-on-chip platforms, offer innovative approaches to mimic the structural and functional complexity of the human lung. These models enable the recreation of key aspects of the tubercular granulomas, such as cellular interactions, oxygen gradients, and nutrient limitations, thereby providing deeper insights into Mtb pathogenesis. This review aims to elucidate the advantages of 3D in vitro systems in bridging the translational gap between traditional experimental approaches and clinical applications. Particular emphasis is placed on their potential to address challenges related to genetic variability in both the host and pathogen, thereby advancing tubercular research and therapeutic development.

Analysis of MLKL, RIP1 and RIP3 Immunostaining Markers in Human Liver Tissue from Fatal Yellow Fever Cases: Insights into Necroptosis

Necroptosis is a regulated form of cell death implicated in several pathological conditions, including viral infections. In this study, we investigated the expression and correlation of necroptosis markers MLKL, RIP1 and RIP3 in human liver tissue from fatal cases of yellow fever (YF) using immunohistochemistry (IHC). The liver samples were obtained from 21 YF-positive individuals and five flavivirus-negative controls with preserved liver parenchymal architecture. The cases underwent histopathological analysis, followed by tissue immunostaining with the immunohistochemical method of streptavidin-biotin peroxidase. Using the in situ method, we evaluated the centrilobular zone (Z3), midzonal zone (Z2), periportal zone and portal tract (PT) of human liver parenchyma with markers for necroptosis, RIPK1, RIPK3 and MLKL. A quantitative analysis revealed a significantly higher expression of MLKL, RIP1 and RIP3 in the liver parenchyma of YF cases compared to controls in different zones (Z3, Z2, Z1) and portal tracts (PTs) of the liver, especially in zone 2. Immunostaining confirmed the localization of MLKL, RIP1 and RIP3 in hepatocytes and inflammatory infiltrates, highlighting their involvement in the pathogenesis of YF. A Pearson correlation analysis demonstrated significant correlations among necroptosis markers, which indicates their coordinated regulation during YF-induced liver injury.

Developing Gingerol-Based Analogs against Pseudomonas aeruginosa Infections

Pseudomonas aeruginosa (P. aeruginosa), a Gram-negative opportunistic pathogen, produces virulent factors and forms biofilms through a quorum sensing (QS) mechanism. Modulating QS networks is considered an effective strategy for treating P. aeruginosa infections. Particularly, the rhl system, one of the QS networks, can be a potential target in treating patients with chronic infections. We previously discovered that gingerol acts as a RhlR antagonist of P. aeruginosa. Based on the chemical structure of gingerol, we have designed and synthesized gingerol derivatives by introducing various functional groups in the middle and tail regions. A comprehensive structure-activity relationship study showed that compound 5a substituted with phenyl group in the tail region was the most potent in various biological assessments, such as RhlR binding affinity, rhl gene expression, and virulence factor production of P. aeruginosa. Furthermore, compound 5a decreased the biofilm formation and pathogenicity of P. aeruginosa. Interestingly, compound 5a also influenced las system in addition to the rhl system. Taken together, compound 5a can be utilized as a potent compound for controlling P. aeruginosa infection.

Femtosecond Laser-Induced Photothermal Effects of Ultrasmall Plasmonic Gold Nanoparticles on the Viability of Human Hepatocellular Carcinoma HepG2 Cells

Laser-induced photothermal therapy using gold nanoparticles (AuNPs) has emerged as a promising approach to cancer therapy. However, optimizing various laser parameters is critical for enhancing the photothermal conversion efficacy of plasmonic nanomaterials. In this regard, the present study investigates the photothermal effects of dodecanethiol-stabilized hydrophobic ultrasmall spherical AuNPs (TEM size 2.2 ± 1.1 nm), induced by a 343 nm wavelength ultrafast femtosecond-pulse laser with a low intensity (0.1 W/cm2) for 5 and 10 min, on the cell morphology and viability of human hepatocellular carcinoma (HepG2) cells treated in vitro. The optical microscopy images showed considerable alteration in the overall morphology of the cells treated with AuNPs and irradiated with laser light. Infrared thermometer measurements showed that the temperature of the cell medium treated with AuNPs and exposed to the laser increased steadily from 22 °C to 46 °C and 48.5 °C after 5 and 10 min, respectively. The WST-1 assay results showed a significant reduction in cell viability, demonstrating a synergistic therapeutic effect of the femtosecond laser and AuNPs on HepG2 cells. The obtained results pave the way to design a less expensive, effective, and minimally invasive photothermal approach to treat cancers with reduced side effects.

Regulated Cell Death of Alveolar Macrophages in Acute Lung Inflammation: Current Knowledge and Perspectives

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a common and serious clinical lung disease characterized by extensive alveolar damage and inflammation leading to impaired gas exchange. Alveolar macrophages (AMs) maintain homeostatic properties and immune defenses in lung tissues. Several studies have reported that AMs are involved in and regulate ALI/ARDS onset and progression via different regulated cell death (RCD) programs, such as pyroptosis, apoptosis, autophagic cell death, and necroptosis. Notably, the effects of RCD in AMs in disease are complex and variable depending on the environment and stimuli. In this review, we provide a comprehensive perspective on how regulated AMs death impacts on ALI/ARDS and assess its potential in new therapeutic development. Additionally, we describe the crosstalk between different RCD types in ALI, and provide new perspectives for the treatment of ALI/ARDS and other severe lung diseases.

AVL-armed oncolytic vaccinia virus promotes viral replication and boosts antitumor immunity via increasing ROS levels in pancreatic cancer

Pancreatic malignant neoplasm is an extremely deadly malignancy well known for its resistance to traditional therapeutic approaches. Enhanced treatments are imperative for individuals diagnosed with pancreatic cancer (PC). Recent investigations have shed light on the wide-ranging anticancer properties of genetic therapy facilitated by oncolytic vaccinia virus. To illuminate the precise impacts of Aphrocallistes vastus lectin-armed oncolytic vaccinia virus (oncoVV-AVL) on PC, AsPC-1 and PANC-1 cells underwent treatment with oncoVV-AVL. Our findings revealed that oncoVV-AVL possesses the capacity to heighten oncolytic effects on PC cells and incite the production of diverse cytokines like tumor necrosis factor-α, interleukin-6 (IL-6), IL-8, and interferon-I (IFN-I), without triggering antiviral responses. Additionally, oncoVV-AVL can significantly elevate the levels of ROS in PC cells, initiating an oxidative stress response that promotes viral replication, apoptosis, and autophagy. Moreover, in xenograft tumor models, oncoVV-AVL notably restrained PC growth, enhanced IFN-γ levels in the bloodstream, and reprogrammed macrophages. Our investigation indicates that oncoVV-AVL boosts the efficacy of antitumor actions against PC tumors by orchestrating reactive oxygen species-triggered viral replication, fostering M1 polarization, and reshaping the tumor microenvironment to transform cold PC tumors into hot ones. These findings imply that oncoVV-AVL could present a novel therapeutic approach for treating PC tumors.

The exploration of high production of tiancimycins in Streptomyces sp. CB03234-S revealed potential influences of universal stress proteins on secondary metabolisms of streptomycetes

BACKGROUND

Universal stress proteins (USPs) are prevalent in various bacteria to cope with different adverse stresses, while their possible effects on secondary metabolisms of hosts are unclear. Tiancimycins (TNMs) are ten-membered endiynes possessing excellent potential for development of anticancer antibody-drug conjugates. During our efforts to improve TNMs titer, a high-producing strain Streptomyces sp. CB03234-S had been obtained and its possible high yield mechanism is being continuously explored to further enhance TNMs production.

RESULTS

In this work, the whole-genome resequencing and analysis results revealed a notable 583 kb terminal deletion containing 8 highly expressed usp genes in the genome of CB03234-S. The individual complementation of lost USPs in CB03234-S all showed differential effects on secondary metabolism, especially TNMs production. Among them, the overexpression of USP3 increased TNMs titer from 12.8 ± 0.2 to 31.1 ± 2.3 mg/L, while the overexpression of USP8 significantly reduced TNMs titer to only 1.0 ± 0.1 mg/L, but activated the production of porphyrin-type compounds. Subsequent genetic manipulations on USP3/USP8 orthologs in Streptomyces. coelicolor A3(2) and Streptomyces sp. CB00271 also presented clear effects on the secondary metabolisms of hosts. Further sequence similarity network analysis and Streptomyces-based pan‑genomic analysis suggested that the USP3/USP8 orthologs are widely distributed across Streptomyces.

CONCLUSION

Our studies shed light on the potential effects of USPs on secondary metabolisms of streptomycetes for the first time, and USPs could become novel targets for exploring and exploiting natural products in streptomycetes.

Identification of key necroptosis-related genes and immune landscape in patients with immunoglobulin A nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is a major cause of chronic kidney disease (CKD) and kidney failure. Necroptosis is a novel type of programmed cell death that has been proved to be associated with the pathogenesis of infectious disease, cardiovascular disease, neurological disorders and so on. However, the role of necroptosis in IgAN remains unclear.

METHODS

In this study, we explored the role of necroptosis-related genes in the pathogenesis of IgAN using a comprehensive bioinformatics method. Microarray datasets GSE93798 and GSE115857 were downloaded from Gene Expression Omnibus (GEO). "limma" package of R software was employed to identify necroptosis-related differentially expressed genes (NRDEGs) between IgAN and healthy controls. GO and KEGG functional enrichment analysis was performed by Clusterprofiler. Least absolute shrinkage and selection operator (LASSO) regression analysis identified hub NRDEGs. We further established a diagnostic model consisting of 7 diagnostic hub NRDEGs and validated the efficacy by an external dataset. The expression of hub genes was confirmed in sc-RNA dataset GSE171314. Immune infiltration, gene set enrichment analysis and transcription factor binding motifs enrichment analysis were conducted to further uncover their roles.

RESULTS

1076 differentially expressed genes were identified between healthy individuals and IgAN patients from RNA-seq dataset GSE9379. Then we cross-linked them with necroptosis-related genes to obtain 9 NRDEGs. LASSO regression analysis screened out 7 hub genes (JUN, CD274, SERTAD1, NFKBIA, H19, UCHL1 and EZH2) of IgAN. We further conducted functional enrichment analysis and constructed the diagnostic model based on dataset GSE93798. GSE115857 was used as the independent validation cohort and indicated a great predictive efficacy. Immune infiltration, gene set enrichment analysis and transcription factor binding motifs enrichment analysis revealed their potential function. Finally, we screened out four drugs that were predicted to have therapeutic value of IgAN.

CONCLUSIONS

In summary, we identified 7 hub necroptosis-associated genes, which can be used as potential genetic biomarkers for IgAN prediction and treatment. Four drugs were predicted as the potential therapeutic solutions. Collectively, we provided insights into the necroptosis-related mechanisms and treatment of IgAN at the transcriptome level.

The Bacterial Biofilms: Formation, Impacts, and Possible Management Targets in the Healthcare System

Introduction: The persistent increase in multidrug-resistant pathogens has catalyzed the creation of novel strategies to address antivirulence and anti-infective elements. Such methodologies aim to diminish the selective pressure exerted on bacterial populations, decreasing the likelihood of resistance emergence. This review explores the role of biofilm formation as a significant virulence factor and its impact on the development of antimicrobial resistance (AMR). Case Presentation: The ability of bacteria to form a superstructure-biofilm-has made resistance cases in the microbial world a big concern to public health and other sectors as it is a crucial virulence factor that causes difficulties in the management of infections, hence enhancing chronic infection occurrence. Biofilm formation dates to about 3.4 billion years when prokaryotes were discovered to be forming them and since then due to evolution and growth in science, they are more understood. Management and Outcome: The unique microenvironments within bacterial biofilms diminish antibiotic effectiveness and help bacteria evade the host immune system. Biofilm production is a widespread capability among diverse bacterial species. Biofilm formation is enhanced by quorum sensing (QS), reduction of nutrients, or harsh environments for the bacteria. Conclusion: The rise of severe, treatment-resistant biofilm infections poses major challenges in medicine and agriculture, yet much about how these biofilms form remains unknown.

Mechanisms of H2pmen-Induced cell death: Necroptosis and apoptosis in MDA cells, necrosis in MCF7 cells

Breast cancer is the second leading cause of cancer-related deaths in women around the world. Several cancer therapeutics have already been discovered and are being used to treat breast cancer. However, most of them cause severe side effects. H2pmen, a tetradentate ligand, was used in this study to investigate its cytotoxic effects on growth, viability, and induction of cell death in MCF7 and MDA cells. The cell viability was determined by treating cells with different concentrations of H2pmen. MTT assay was used to obtain an IC50, and the cells were then assayed for membrane damage, apoptotic induction, and metabolism. Protein expression of Bax, p53, Bcl2, and xIAP was identified using Western blot analysis. The gene expression of RIPK1, RIPK3, and MKLK was determined using qPCR. In MDA cells, H2pmen increases cytotoxicity, as evidenced by upregulated LDH and JC-10, and enhances apoptosis, indicated by upregulated caspase-3/7 and Bax. In contrast, MCF7 cells exhibit a more stable profile with downregulated LDH and Annexin V Activity. MCF7 cells also show reduced necroptosis and increased necrosis. These findings highlight that H2pmen induces varied cytotoxic effects across MDA and MCF7 cells, with MDA cells exhibiting more pronounced apoptosis and necroptosis alongside complex anti-apoptotic responses.

Infection biology of Salmonella enterica

Salmonella enterica is the leading cause of bacterial foodborne illness in the USA, with an estimated 95% of salmonellosis cases due to the consumption of contaminated food products. Salmonella can cause several different disease syndromes, with the most common being gastroenteritis, followed by bacteremia and typhoid fever. Among the over 2,600 currently identified serotypes/serovars, some are mostly host-restricted and host-adapted, while the majority of serotypes can infect a broader range of host species and are associated with causing both livestock and human disease. Salmonella serotypes and strains within serovars can vary considerably in the severity of disease that may result from infection, with some serovars that are more highly associated with invasive disease in humans, while others predominantly cause mild gastroenteritis. These observed clinical differences may be caused by the genetic make-up and diversity of the serovars. Salmonella virulence systems are very complex containing several virulence-associated genes with different functions that contribute to its pathogenicity. The different clinical syndromes are associated with unique groups of virulence genes, and strains often differ in the array of virulence traits they display. On the chromosome, virulence genes are often clustered in regions known as Salmonella pathogenicity islands (SPIs), which are scattered throughout different Salmonella genomes and encode factors essential for adhesion, invasion, survival, and replication within the host. Plasmids can also carry various genes that contribute to Salmonella pathogenicity. For example, strains from several serovars associated with significant human disease, including Choleraesuis, Dublin, Enteritidis, Newport, and Typhimurium, can carry virulence plasmids with genes contributing to attachment, immune system evasion, and other roles. The goal of this comprehensive review is to provide key information on the Salmonella virulence, including the contributions of genes encoded in SPIs and plasmids during Salmonella pathogenesis.

Chloroform Extract from Fermented Viola mandshurica Regulates LPS-Induced Inflammation Response in RAW 264.7 Cells by Inhibiting iNOS and COX-2

Inflammatory is a crucial part of the immune system of body protect it from harmful invaders, such as bacteria, viruses, and other foreign substances. In this study, the effects of chloroform extract of fermented Viola mandshurica (CEFV) on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophages were investigated. The CEFV significantly inhibited NO production and reduced the expression of inducible nitric oxide synthase (iNOS) at both protein and mRNA levels in a dose-dependent manner. Also, CEFV decreased PGE2 production, suppressed COX-2 expression, and inhibited the activation of the ERK and JNK pathways but not the p38 pathway. Taken together, CEFV suppressed NF-κB activation, which is a key regulator in the inflammatory response. The main phenolic compounds identified in CEFV were tectoridin, luteolin, resveratrol, and hesperetin. Therefore, in this study, CEFC exhibits potent anti-inflammatory effects by downregulating the production of pro-inflammatory mediators and inhibiting key inflammatory pathway in RAW264.7 cells.

Green synthesis of ZnO nanoparticles: in-silico and in-vitro assessment of anticancer and antibacterial activity and biomolecule (DNA) binding analysis

The zinc oxide nanoparticles (ZnO NPs) were synthesized by a green chemistry approach utilizing Stachys schtschegleevii Sosn.) S. schtchegleevii (extract, aims to innovate by employing environmentally friendly techniques. The production of ZnO NPs was confirmed by FT-IR, zeta potential, TEM, SEM-EDX, DLS and ultraviolet-visible techniques. The antibacterial potency of the ZnO NPs was evaluated toward pathogenic strains of E. coli and S. aureus. The antibacterial efficacy of this NPs against the selected bacteria followed the sequence: S. aureus > E. coli. The results of the MTT assay indicate that ZnO NPs have significant anticancer potential against the MCF-7 cell line. Furthermore, the synthesized ZnO NPs demonstrate a stronger inhibitory effect compared to the extract on the cancer cell line. To find out the potential of ZnO NPs as therapeutics, interaction process with calf-thymus DNA (ct-DNA) was performed by using absorption, and fluorescence studies. The evaluation of the fluorescence spectra and UV-visible absorption showed a satisfactory association of the ZnO NPs with ct-DNA. Besides, to clarify the binding interactions of ZnO NPs with the enzymes and ct-DNA, molecular docking simulation was performed. The molecular docking' results show a well compromise with our experimental results. In total, the present investigation employs ZnO NPs synthesized through green methods as an efficient strategy for the purpose of the potentiation of anticancer and antibacterial activities in a biocompatible manner.

The emerging challenge of Enterococcus faecalis endocarditis after transcatheter aortic valve implantation: time for innovative treatment approaches

SUMMARYInfective endocarditis (IE) is a life-threatening infection that has nearly doubled in prevalence over the last two decades due to the increase in implantable cardiac devices. Transcatheter aortic valve implantation (TAVI) is currently one of the most common cardiac procedures. TAVI usage continues to exponentially rise, inevitability increasing TAVI-IE. Patients with TAVI are frequently nonsurgical candidates, and TAVI-IE 1-year mortality rates can be as high as 74% without valve or bacterial biofilm removal. Enterococcus faecalis, a historically less common IE pathogen, is the primary cause of TAVI-IE. Treatment options are limited due to enterococcal intrinsic resistance and biofilm formation. Novel approaches are warranted to tackle current therapeutic gaps. We describe the existing challenges in treating TAVI-IE and how available treatment discovery approaches can be combined with an in silico "Living Heart" model to create solutions for the future.

Harnessing the Power of Our Immune System: The Antimicrobial and Antibiofilm Properties of Nitric Oxide

Nitric oxide (NO) is a free radical of the human innate immune response to invading pathogens. NO, produced by nitric oxide synthases (NOSs), is used by the immune system to kill microorganisms encapsulated within phagosomes via protein and DNA disruption. Owing to its ability to disperse biofilm-bound microorganisms, penetrate the biofilm matrix, and act as a signal molecule, NO may also be effective as an antibiofilm agent. NO can be considered an underappreciated antimicrobial that could be levied against infected, at-risk, and hard-to-heal wounds due to the inherent lack of bacterial resistance, and tolerance by human tissues. NO produced within a wound dressing may be an effective method of disrupting biofilms and killing microorganisms in hard-to-heal wounds such as diabetic foot ulcers, venous leg ulcers, and pressure injuries. We have conducted a narrative review of the evidence underlying the key antimicrobial and antibiofilm mechanisms of action of NO for it to serve as an exogenously-produced antimicrobial agent in dressings used in the treatment of hard-to-heal wounds.

Cell-Cycle-Related and Expression Elevated Protein in Tumor Upregulates the Antioxidant Genes via Activation of NF-κB/Nrf2 in Acute Liver Injury

BACKGROUND AND AIMS

Cell-cycle-related and expression elevated protein in tumor (CREPT, also named RPRD1B) is highly expressed in tumors and functions to promote tumorigenesis. However, the role of CREPT in the pathophysiology of acute liver injury is limited. Here, we demonstrate that CREPT plays an essential role during acute liver injury.

APPROACH AND RESULTS

Hepatocyte-specific CREPT knockout (CREPThep-/-) and CREPTflox/flox mice were generated and subjected to the CCl4 challenge for the acute (24 h) liver injury. The acute CCl4 challenge triggered increased inflammation as well as liver injury, associated with stronger apoptotic and necroptotic cell death in CREPThep-/- mice. CREPT knockout down-regulated the expression of different genes involved in cell survival, inflammation and fibrosis under acute CCl4 challenge conditions. Antioxidant enzymes such as superoxide dismutase 2 (Sod2) and ferritin heavy chain 1 (Fth1) are dramatically induced at 24 h post-CCl4 treatment, but this induction is blocked by transcriptional inactivation of NF-κB/Nrf2, indicating that CREPT might promote hepatocyte survival in acute liver injury by participating in the transactivation of antioxidant genes.

CONCLUSIONS

These results elucidate the role of CREPT in acute liver injury and provide hints for future research on how CREPT might function in hepatocyte renewal.

Terrein: isolation, chemical synthesis, bioactivity and future prospects of a potential therapeutic fungal metabolite

The increasing risk of drug-resistant infections and unexpected pandemics like Covid-19 has prompted researchers to explore the area of drug repurposing. Natural products, being a result of the evolutionary optimisation processes can be potential starting points for such drug discovery programs. One such unexplored chemical is terrein, a secondary fungal metabolite. Although discovered in 1935 from Aspergillus terreus, the therapeutic potential of terrein has largely remained undeciphered. Research has primarily been focused on its biosynthetic pathways and its mycotoxic effects. However, in the last two decades, its biological properties including anticancer, anti-inflammatory anti-melanogenic, and bacteriocidal activities have been reported. These reports are preliminary in nature and do not adequately establish its overall therapeutic application. From its structural and therapeutic properties, it can be conjectured that terrein may act as a novel multimodal therapeutic. This comprehensive study reviews the synthesis, production and application aspects of terrein to understand its importance.

Green Synthesis of Zinc Oxide Nanoparticles: Preparation, Characterization, and Biomedical Applications - A Review

Over the last decade, biomedical nanomaterials have garnered significant attention due to their remarkable biological properties and diverse applications in biomedicine. Metal oxide nanoparticles (NPs) are particularly notable for their wide range of medicinal uses, including antibacterial, anticancer, biosensing, cell imaging, and drug/gene delivery. Among these, zinc oxide (ZnO) NPs stand out for their versatility and effectiveness. Recently, ZnO NPs have become a primary material in various sectors, such as pharmaceutical, cosmetic, antimicrobials, construction, textile, and automotive industries. ZnO NPs can generate reactive oxygen species and induce cellular apoptosis, thus underpinning their potent anticancer and antibacterial properties. To meet the growing demand, numerous synthetic approaches have been developed to produce ZnO NPs. However, traditional manufacturing processes often involve significant economic and environmental costs, prompting a search for more sustainable alternatives. Intriguingly, biological synthesis methods utilizing plants, plant extracts, or microorganisms have emerged as ideal for producing ZnO NPs. These green production techniques offer numerous medicinal, economic, environmental, and health benefits. This review highlights the latest advancements in the green synthesis of ZnO NPs and their biomedical applications, showcasing their potential to revolutionize the field with eco-friendly and cost-effective solutions.

Anti-necroptotic effects of human Wharton's jelly-derived mesenchymal stem cells in skeletal muscle cell death model via secretion of GRO-α

Human mesenchymal stem cells (hMSCs) have therapeutic applications and potential for use in regenerative medicine. However, the use of hMSCs in research and clinical medicine is limited by a lack of information pertaining to their donor-specific functional attributes. In this study, we compared the characteristics of same-donor derived placenta (PL) and Wharton's jelly (WJ)-derived hMSCs, we also compared their mechanism of action in a skeletal muscle disease in vitro model. The same-donor-derived hWJ- and hPL-MSCs exhibited typical hMSC characteristics. However, GRO-α was differentially expressed in hWJ- and hPL-MSCs. hWJ-MSCs, which secreted a high amount of GRO-α, displayed a higher ability to inhibit necroptosis in skeletal muscle cells than hPL-MSCs. This demonstrates the anti-necroptotic therapeutic effect of GRO-α in the skeletal muscle cell death model. Furthermore, GRO-α also exhibited the anti-necroptotic effect in a Duchenne muscular dystrophy (DMD) mouse model. Considering their potential to inhibit necroptosis in skeletal muscle cells, hWJ-MSCs and the derived GRO-α are novel treatment options for skeletal muscle diseases such as DMD.

Antibacterial and antibiofilm activity of human gut lactic acid bacteria

The present study focused on the antibacterial and antibiofilm activity of novel lactic acid bacterial (LAB) strains isolated from the healthy human volunteers of different age groups and their consortium (LABCON), against the enteropathogenic bacteria. From the study, methanolic extract of LAB isolates and their consortia were found to have promising antibacterial activity and antibiofilm activity against Escherichia coli (ATCC 35218) and Staphylococcus aureus (ATCC 25923). The antimicrobial compounds including the DL-3 phenyllactic acid, DL-p-hydroxyphenyllactic acid, and Succinic acid produced by the LAB could be considered to inhibit the growth and biofilm formation by E. coli (ATCC 35218) and S. aureus (ATCC 25923). Detailed insight into the antibiofilm activity could also be demonstrated by Confocal Raman microscopy attached with AFM and Fluorescent microscope. From the results of the study, the consortium LABCON was superior in antimicrobial and antibiofilm activity and can be considered to have promising application in infection control.

S-nitrosoglutathione (GSNO) induces necroptotic cell death in K562 cells: Involvement of p73, TSC2 and SIRT1

BACKGROUND

Nitric oxide and Reactive Nitrogen Species are known to effect tumorigenicity. GSNO is one of the main NO carrying signalling moiety in cell. In the current study, we tried to delve into the effect of GSNO induced nitrosative stress in three different myelogenous leukemic K562, U937 and THP-1 cell lines.

METHOD

WST-8 assay was performed to investigate cell viability. RT-PCR and western-blot analysis were done to investigate mRNA and protein expression. Spectrophotometric and fluorimetric assays were done to investigate enzyme activities.

RESULT

We found that GSNO exposure led to reduced cell viability and the mode of cell death in K562 was non apoptotic in nature. GSNO promoted impaired autophagic flux and necroptosis. GSNO treatment heightened phosphorylation of AMPK and TSC2 and inhibited mTOR pathway. We observed increase in NAD+/ NADH ratio following GSNO treatment. Increase in both SIRT1 m-RNA and protein expression was observed. While total SIRT activity remained unaltered. GSNO increased tumor suppressor TAp73/ oncogenic ∆Np73 ratio in K562 cells which was correlated with cell mortality. Surprisingly, GSNO did not alter cellular redox status or redox associated protein expression. However, steep increase in total SNO and PSNO content was observed. Furthermore, inhibition of autophagy, AMPK phosphorylation or SIRT1 exacerbated the effect of GSNO. Altogether our work gives insights into GSNO mediated necroptotic event in K562 cells which can be excavated to develop NO based anticancer therapeutics.

CONCLUSION

Our data suggests that GSNO could induce necroptotic cell death in K562 through mitochondrial dysfunctionality and PTM of different cellular proteins.

Stealing survival: Iron acquisition strategies of Mycobacteriumtuberculosis

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), faces iron scarcity within the host due to immune defenses. This review explores the importance of iron for Mtb and its strategies to overcome iron restriction. We discuss how the host limits iron as an innate immune response and how Mtb utilizes various iron acquisition systems, particularly the siderophore-mediated pathway. The review illustrates the structure and biosynthesis of mycobactin, a key siderophore in Mtb, and the regulation of its production. We explore the potential of targeting siderophore biosynthesis and uptake as a novel therapeutic approach for TB. Finally, we summarize current knowledge on Mtb's iron acquisition and highlight promising directions for future research to exploit this pathway for developing new TB interventions.

Advances in understanding cisplatin-induced toxicity: Molecular mechanisms and protective strategies

Cisplatin, a widely used chemotherapeutic agent, has proven efficacy against various malignancies. However, its clinical utility is hampered by its dose-limiting toxicities, including nephrotoxicity, ototoxicity, neurotoxicity, and myelosuppression. This review aims to provide a comprehensive overview of cisplatin toxicity, encompassing its underlying mechanisms, risk factors, and emerging therapeutic strategies. The mechanisms of cisplatin toxicity are multifactorial and involve oxidative stress, inflammation, DNA damage, and cellular apoptosis. Various risk factors contribute to the interindividual variability in susceptibility to cisplatin toxicity. The risk of developing cisplatin-induced toxicity could be related to pre-existing conditions, including kidney disease, hearing impairment, neuropathy, impaired liver function, and other comorbidities. Additionally, this review highlights the emerging therapeutic strategies that could be applied to minimize cisplatin-induced toxicities and aid in optimizing cisplatin treatment regimens, improving patient outcomes, and enhancing the overall quality of cancer care.

Insights into the protective effect of omega-3 nanoemulsion against colistin-induced nephrotoxicity in experimental rats: regulation of autophagy and necroptosis via AMPK/mTOR and RIPK1/RIPK3/MLKL signaling pathways

Colistin is considered one of the most effective antibiotics against gram-negative bacteria. However, nephrotoxicity is one of the dose-limiting factors in its treatment. This study aimed to evaluate the outcome of omega-3 nanoemulsion against colistin-induced nephrotoxicity and its possible underlying mechanism. Four rat groups were involved in the present research; each group containing ten rats was divided as follows: Group I (control) rats received normal saline; Group II (omega-3 nanoemulsion) rats received a dose of 500 mg/kg/body weight orally; Group III (colistin) rats received colistin intraperitoneally (300.000 IU/kg/day); and Group IV (colistin/omega-3 nanoemulsion) rats were treated for six days. The results revealed that colistin administration caused deterioration in renal functions such as creatinine, blood urea nitrogen, 24 h proteinuria, and kidney injury molecule-1 with decrease in creatinine clearance, resulting in histological alternation and tubular damage with diffuse interstitial inflammation. Additionally, colistin significantly increased the lipid peroxidation marker malonaldehyde, proinflammatory cytokines tumor necrosis alpha, interleukin-6, interleukin-1 beta. Also, autophagy influx marker microtubule-associated protein light chain 3B, Beclin-1, and necroptotic related proteins, receptor-interacting protein kinase-3 (RIPK-3), RIPK-1, mixed lineage kinase domain-like protein, and autophagy pathway regulatory kinase AMP-activated protein kinase, with a decrease in antioxidant enzymes catalase, superoxide dismutase, and total antioxidant capacity, autophagic marker ubiquitin-binding protein (p62), and regulator Mammalian target of rapamycin. Interestingly, omega-3 nanoemulsion reversed the results above, dramatically improving renal function and histological picture. Thus, omega-3 nanoemulsion provided a notable method for suppressing colistin-induced nephrotoxicity via its antioxidant and anti-inflammatory power, inhibiting pathological autophagy and necroptosis.

Erythronecroptosis: an overview of necroptosis or programmed necrosis in red blood cells

Necroptosis is considered a programmed necrosis that requires receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and pore-forming mixed lineage kinase domain-like protein (MLKL) to trigger a regulated cell membrane lysis. Membrane rupture in necroptosis has been shown to fuel innate immune response due to release of damage-associated molecular patterns (DAMPs). Recently published studies indicate that mature erythrocytes can undergo necroptosis as well. In this review, we provide an outline of multiple cell death modes occurring in erythrocytes, discuss possible immunological aspects of diverse erythrocyte cell deaths, summarize available evidence related to the ability of erythrocytes to undergo necroptosis, outline key involved molecular mechanisms, and discuss the potential implication of erythrocyte necroptosis in the physiology and pathophysiology. Furthermore, we aim to highlight the interplay between necroptosis and eryptosis signaling in erythrocytes, emphasizing specific characteristics of these pathways distinct from their counterparts in nucleated cells. Thus, our review provides a comprehensive summary of the current knowledge of necroptosis in erythrocytes. To reflect critical differences between necroptosis of nucleated cells and necroptosis of erythrocytes, we suggest a term erythronecroptosis for necroptosis of enucleated cells.

Synergistic combinations of novel polymyxins and rifampicin with improved eradication of colistin-resistant Pseudomonas aeruginosa biofilms

Background

Increased prevalence of antimicrobial resistance coupled with a lack of new antibiotics against Gram-negative bacteria emphasize the imperative for novel therapeutic strategies. Colistin-resistant Pseudomonas aeruginosa constitutes a challenge, where conventional treatment options lack efficacy, in particular for biofilm-associated infections. Previously, synergy of colistin with other antibiotics was explored as an avenue for the treatment of colistin-resistant infections, and recently we reported our efforts towards colistin analogs capable of combating planktonic colistin-resistant strains.

Aims

The aim of the present study was to investigate whether analogs of polymyxin B with improved potency in wild-type and moderate resistant Gram-negative pathogens would retain similarly increased activity in highly colistin-resistant clinical P. aeruginosa isolates (in planktonic and biofilm growth) when applied alone and in combination with rifampicin.

Materials and methods

In this in vitro study, we tested three analogs of polymyxin B prepared by solid-phase peptide synthesis. Antimicrobial susceptibility testing was performed by measurement of minimum inhibitory concentrations via the broth microdilution method. Interactions between two antimicrobials was quantified in a checkerboard broth microdilution assay by calculating the fractional inhibitory concentration index for each combination. For testing of antibiofilm activity a previously described model with alginate beads encapsulating a biofilm culture was applied. The minimum biofilm eradication concentrations (MBECs) were evaluated, and the fractional biofilm eradication concentration indices were calculated. Three recently identified colistin analogs (CEP932, CEP936 and CEP938) were tested against three isogenic pairs of colistin-susceptible and colistin-resistant P. aeruginosa clinical isolates as well as the reference strain PAO1.

Results

For bacteria in planktonic growth CEP938 retained almost full potency in all three resistant isolates, while exhibiting similar activity as colistin in susceptible isolates. Against biofilms CEP938 was slightly more potent against PAO1 as compared to colistin, while also retaining activity against a biofilm of the colistin-resistant strain 41,782/98. Next, synergy between CEP938 and the antibiotic rifampicin was explored. Interestingly, CEP938 did not exhibit synergy with rifampicin in planktonic cultures. Importantly, for colistin-resistant biofilms the CEP938-rifampicin combination demonstrated activity superior to that found for the colistin-rifampicin combination.

Conclusions

The present study showed in vitro efficacy of CEP938 against both colistin-susceptible and colistin-resistant P. aeruginosa biofilms as well as an ability of CEP938 to synergize with rifampicin in biofilm eradication.

Enhancing biocompatibility of the brain-machine interface: A review

In vivo implantation of microelectrodes opens the door to studying neural circuits and restoring damaged neural pathways through direct electrical stimulation and recording. Although some neuroprostheses have achieved clinical success, electrode material properties, inflammatory response, and glial scar formation at the electrode-tissue interfaces affect performance and sustainability. Those challenges can be addressed by improving some of the materials' mechanical, physical, chemical, and electrical properties. This paper reviews materials and designs of current microelectrodes and discusses perspectives to advance neuroprosthetics performance.

Molecular epidemiology of human papillomavirus variants in cervical cancer in India

Background & objectives Cervical cancer (CC) has been documented as the fourth most common cancer worldwide. Persistent infections with high-risk human papillomavirus (hr-HPV) have been suggested in the development of CC. Although prophylactic vaccines are available for the prevention of prevalent hr-HPV types, intra-type variations exist within a particular HPV type that has varying oncogenic potential as well as the mechanism of pathogenicity and varying neutralization by antibodies. Therefore, we carried out a systematic review to determine the distribution of HPV intra-typic variations in different geographical locations of India and their reported implications. Methods Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed to retrieve relevant articles from the standard databases using appropriate keywords. Consequently, 17 articles were included in the current review after screening based on inclusion and exclusion criteria. Results The majority of articles included in this review reported variations within the HPV16 E6 gene, followed by the L1 and E7 genes. Analysis of available data indicated the differential regional distribution of some variations. These variations have also been reported to impact the biological functions of various viral proteins. Interpretation & conclusions The distribution of lineages varied with the different genomic regions sequenced. Additionally, there were certain unique and common variations in the HPV genome with respect to geographical regions. Hence, we suggest the identification of region-specific variations for the development of diagnostic and prognostic interventions.

Optimal ultrasonic treatment frequency and duration parameters were used to detect the pathogenic bacteria of orthopedic implant-associated infection by ultrasonic oscillation

INTRUDUCTON

The most accurate method for detecting the pathogen of orthopedic implant-associated infections (OIAIs) is sonication fluid (SF). However, the frequency and duration of ultrasound significantly influence the number and activity of microorganisms. Currently, there is no consensus on the selection of these two parameters. Through this study, the choice of these two parameters is clarified.

METHODS

We established five ultrasonic groups (40kHz/10min, 40kHz/5min, 40 kHz/1min, 20kHz/5min, and 10kHz/5min) based on previous literature. OIAIs models were then developed and applied to ultrasound group treatment. Subsequently, we evaluated the efficiency of bacteria removal by conducting SEM and crystal violet staining. The number of live bacteria in the SF was determined using plate colony count and live/dead bacteria staining.

RESULTS

The results of crystal violet staining revealed that both the 40kHz/5min group and the 40kHz/10min group exhibited a significantly higher bacterial clearance rate compared to the other groups. However, there was no significant difference between the two groups. Additionally, the results of plate colony count and fluorescence staining of live and dead bacteria indicated that the number of live bacteria in the 40kHz/5min SF group was significantly higher than in the other groups.

CONCLUSION

40kHz/5min ultrasound is the most beneficial for the detection of pathogenic bacteria on the surface of orthopedic implants.

Colistin, doxycycline and Labetalol-meropenem combination are the most active against XDR-Carbapenem-resistant Acinetobacter baumannii: Role of a novel transferrable plasmid conferring carbapenem resistance

This study aimed to evaluate the antimicrobial susceptibility and combination of a beta-blocker, labetalol (LAB) and meropenem (MEM) on Carbapenem-resistant (CR) A. baumannii clinical isolates. A total of 43 CR- A. baumannii were isolated of which 37 (86.6 %) and 28 (65 %) exhibited MDR and XDR phenotypes, respectively. Colistin and doxycycline still retain their activities in 93.1 % and 72.1 % of the isolates, respectively. Combining MEM with LAB at 0.25 mg /mL, decreased MIC values in 91.4 % (32/35) however, at 0.5 mg /mL, it decreased MIC value and restored susceptibility to MEM in 100 % and 91.4 % of the tested isolates, respectively. A novel transferable plasmid pAcbGIM3 harboring aph-3', blaoxa-58,blaGIM3 and blaCTX-M3 and eight mobile genetic elements were successfully isolated from a pan-drug resistant (PDR) isolate. In conclusion, LAB-MEM is a promising combination and should be clinically examined. This is the first report of a transmissible plasmid harboring blaGIM3 gene in Egypt.

Necroptosis-based glioblastoma prognostic subtypes: implications for TME remodeling and therapy response

BACKGROUND

Glioblastoma (GBM) is an aggressive primary brain tumor with a high recurrence rate and poor prognosis. Necroptosis, a pathological hallmark of GBM, is poorly understood in terms of its role in prognosis, tumor microenvironment (TME) alteration, and immunotherapy.

METHODS & RESULTS

We assessed the expression of 55 necroptosis-related genes in GBM and normal brain tissues. We identified necroptosis-stratified clusters using Uni-Cox and Least Absolute Shrinkage and Selection Operator (LASSO) regression to establish the 10-gene Glioblastoma Necroptosis Index (GNI). GNI demonstrated significant prognostic efficacy in the TCGA dataset (n = 160) and internal validation dataset (n = 345) and in external validation cohorts (n = 591). The GNI-high subgroup displayed a mesenchymal phenotype, lacking the IDH1 mutation, and MGMT methylation. This subgroup was characterized by significant enrichment in inflammatory and humoral immune pathways with prominent cell adhesion molecules (CD44 and ICAM1), inflammatory cytokines (TGFB1, IL1B, and IL10), and chemokines (CX3CL1, CXCL9, and CCL5). The TME in this subgroup showed elevated infiltration of M0 macrophages, neutrophils, mast cells, and regulatory T cells. GNI-related genes appeared to limit macrophage polarization, as confirmed by immunohistochemistry and flow cytometry. The top 30% high-risk score subset exhibited increased CD8 T cell infiltration and enhanced cytolytic activity. GNI showed promise in predicting responses to immunotherapy and targeted treatment.

CONCLUSIONS

Our study highlights the role of necroptosis-related genes in glioblastoma (GBM) and their effects on the tumor microenvironment and patient prognosis. TheGNI demonstrates potential as a prognostic marker and provides insights into immune characteristics and treatment responsiveness.

Study on the Mobile Colistin Resistance (mcr-1) Gene in Gram-Negative Bacilli in a Rural Tertiary Care Hospital in Western Maharashtra

BACKGROUND

Colistin, a last-resort antibiotic for treating multidrug-resistant Gram-negative bacterial infections, has increased resistance as a result of the emergence of the mcr-1 gene. The mcr-1gene, which confers colistin resistance, is often carried on plasmids, facilitating its spread by horizontal gene transfer among bacterial populations. The rising prevalence of mcr-1-mediated resistance poses significant challenges for infection control and treatment efficacy. This study aimed to detect and investigate the prevalence of the mcr-1 gene among Gram-negative bacilli isolated from clinical specimens in a rural tertiary care hospital and to analyze the plasmid-mediated mechanisms of colistin resistance.

MATERIALS AND METHODS

A cross-sectional study was conducted over two years at Krishna Institute of Medical Sciences, Karad. Gram-negative bacilli were isolated from clinical specimens and identified using standard methodology. Antimicrobial susceptibility testing was performed by using the Vitek-2 Compact (bioMerieux, Marcy-l'Étoile, France) method and the colistin-resistance broth microdilution method (BMD). Polymerase chain reaction (PCR) was done for the presence of mcr-1 gene in colistin-resistant isolates.

RESULTS

Out of 359 Gram-negative bacilli isolates, 93 (25.90%) demonstrated resistance to colistin. Among these resistant strains, the mcr-1 gene was identified in 13 (13.97%) of the isolates. The gene was predominantly found in Pseudomonas aeruginosa (8, 61.53%), followed by Klebsiella pneumoniae (3, 23.07%), Acinetobacter baumannii (2, 15.38%) among the 13 isolates. Out of the various specimens received, mcr-1 gene was found in endotracheal tube (4, 30.76%), urine (4, 30.76%), pus (3, 23.07%), sputum (1, 7.69%), and blood (1, 7.69%). Colistin minimum inhibitory concentration (MIC) value for these resistant isolates ranged from 4 to 16 µg/ml.

CONCLUSION

The study highlights a significant prevalence of mcr-1 plasmid-mediated colistin resistance gene among Gram-negative bacilli in the hospital. This possibly highlights the frequent misuse of colistin in animal husbandry from this rural area. The findings underscore the importance of monitoring resistance patterns and implementing stringent infection control measures.

Ferroptosis contributes to the progression of female-specific neoplasms, from breast cancer to gynecological malignancies in a manner regulated by non-coding RNAs: Mechanistic implications

Ferroptosis, a recently identified type of non-apoptotic cell death, triggers the elimination of cells in the presence of lipid peroxidation and in an iron-dependent manner. Indeed, ferroptosis-stimulating factors have the ability of suppressing antioxidant capacity, leading to the accumulation of reactive oxygen species (ROS) and the subsequent oxidative death of the cells. Ferroptosis is involved in the pathophysiological basis of different maladies, such as multiple cancers, among which female-oriented malignancies have attracted much attention in recent years. In this context, it has also been unveiled that non-coding RNA transcripts, including microRNAs, long non-coding RNAs, and circular RNAs have regulatory interconnections with the ferroptotic flux, which controls the pathogenic development of diseases. Furthermore, the potential of employing these RNA transcripts as therapeutic targets during the onset of female-specific neoplasms to modulate ferroptosis has become a research hotspot; however, the molecular mechanisms and functional alterations of ferroptosis still require further investigation. The current review comprehensively highlights ferroptosis and its association with non-coding RNAs with a focus on how this crosstalk affects the pathogenesis of female-oriented malignancies, from breast cancer to ovarian, cervical, and endometrial neoplasms, suggesting novel therapeutic targets to decelerate and even block the expansion and development of these tumors.

Usnic acid brief exposure suppresses cariogenic properties and complexity of Streptococcus mutans biofilms

Bacterial biofilms are highly structured surface associated architecture of micro-colonies, which are strongly bonded with the exopolymeric matrix of their own synthesis. These exopolymeric substances, mainly exopolysaccharides (EPS) initially assist the bacterial adhesion and finally form a bridge over the microcolonies to protect them from environmental assaults and antimicrobial exposure. Bacterial cells in dental biofilm metabolize dietary carbohydrates and produce organic acids. The blanket of exopolysaccharides over the bacterial communities hinders the buffering by saliva, contributing to the initiation of tooth decay followed by the progression of dental caries. Considering the current interest towards the use of natural antimicrobial agents to disarm the cariogenic properties of dental biofilm, this study evaluated the antimicrobial activity and the effect of twice daily brief exposure (1 min) of usnic acid on acid production, acid tolerance and development of 3-dimensional architecture of Streptococcus mutans biofilm. Herein, biofilms were briefly treated twice daily during biofilm development and biofilms were analyzed by using biochemical, microbiological and microscopic examination. Results obtained in this study showed a significant reduction in virulence properties of biofilm cells treated with usnic acid in compared to non-treated biofilms. Furthermore, twice daily brief exposure of usnic acid significantly disrupted the acid production and reduced the complexity of Streptococcus mutans biofilm by disrupting the EPS production. Brief exposure of usnic acid inhibited the production of glucosyltransferase (GTF) enzymes and their enzymatic activity leading to inhibition in production of EPS on the biofilm matrix. In conclusion, usnic acid treatment reduced the cariogenic properties and complexity of S. mutans biofilm by inhibiting acid production, acid tolerance and disrupting extracellular polysaccharide (EPS) formation, indicating its potential for preventing dental caries.

Therapeutic efficacy of chitosan-based hybrid nanomaterials to treat microbial biofilms and their infections - A review

Antimicrobial resistance, the biggest issue facing the global healthcare sector, quickly emerged and spread due to the frequent use of antibiotics in regular treatments. The investigation of polymer-based nanomaterials as possible antibiofilm treatment agents is prompted by the growing ineffectiveness of conventional therapeutic techniques against these resistant bacteria species. So far, several articles have been published on microbial biofilm eradication using various polymer-based nanomaterials due to their therapeutic efficacy and biocompatibility nature. Despite their potential, a comprehensive review of the chitosan-based hybrid nanomaterials to treat microbial biofilms and their infections is lacking. This review provides a comprehensive investigation of the current state of therapeutic efficacy, various nanoformulations, advantages, limitations, and regulations of chitosan-based hybrid nanomaterials for biofilm treatment. Special attention is given to the application of chitosan-based nanomaterials in wound care, urinary tract infections, and dental biofilms are discussed, highlighting their role in managing biofilm-associated complications. Researchers will be better able to comprehend and develop unique, marketable chitosan-based nanomaterials with increased activity to treat biofilm infections in near future with the aid of this review.

T Cell Resistance: On the Mechanisms of T Cell Non-activation

Immunological tolerance is a fundamental arm of any functioning immune system. Not only does tolerance mitigate collateral damage from host immune responses, but in doing so permits a robust response sufficient to clear infection as necessary. Yet, despite occupying such a cornerstone, research aiming to unravel the intricacies of tolerance induction is mired by interchangeable and often misused terminologies, with markers and mechanistic pathways that beg the question of redundancy. In this review we aim to define these boarders by providing new perspectives to long-standing theories of tolerance. Given the central role of T cells in enforcing immune cascades, in this review we choose to explore immunological tolerance through the perspective of T cell 'resistance to activation,' to delineate the contexts in which one tolerance mechanism has evolved over the other. By clarifying the important biological markers and cellular players underpinning T cell resistance to activation, we aim to encourage more purposeful and directed research into tolerance and, more-over, potential therapeutic strategies in autoimmune diseases and cancer. The tolerance field is in much need of reclassification and consideration, and in this review, we hope to open that conversation.

Biofilm-producing and carbapenems-resistant Escherichia coli nosocomial uropathogens: a cross-sectional study

OBJECTIVES

This cross-sectional study aims to determine the incidence and potential risk factors associated with biofilm-producing uropathogenic Escherichia coli (UPEC) nosocomial strains from a tertiary care hospital and to examine the prospective correlation between biofilm generation and antibiotic resistance phenotypes and genotypes.

METHODS

A total of 130 UPEC nosocomial isolates were identified, their biofilm formation was quantified using a modified microtiter plate assay, and their antibiotic susceptibilities were assessed utilizing the disc diffusion method. Isolates were then subjected to PCR assays targeting blaKPC, blaVIM, blaIMP, and blaOXA48 genes.

RESULTS

Over half of the isolates (n = 76, 58.5%) were biofilm producers. Among 17 carbapenem-resistant isolates, 6 (42.9%) isolates harbored the blaOXA48 gene, and only 1 (9.1%) isolate was positive for the blaVIM gene. Prior antibiotic therapy (aOR 15.782, p 0.000) and diabetes mellitus DM (aOR 11.222, p 0.016) were the significant risk factors associated with biofilm production, as determined by logistic regression analysis of the data. In addition, gentamicin resistance was the only statistically significant antibiotic resistance pattern associated with biofilm production (aOR 9.113, p 0.02).

CONCLUSIONS

The findings of this study emphasize the significance of implementing proper infection control measures to avoid the horizontal spread of biofilm formation and associated antimicrobial resistance patterns among UPEC nosocomial strains.

Necroptosis and autophagy in cisplatinum-triggered nephrotoxicity: Novel insights regarding their prognostic and diagnostic potential

Necroptosis is an innovative class of programmed autophagy (Atg) and necrosis; considered as a type of homeostatic housekeeping machinery that have observed an escalating concern due to its power in alleviating Cisplatinum-induced nephrotoxicity. This article elucidated in details the prospective role of both autophagy and necroptosis on Cisplatinum-triggered nephrotoxicity and investigating more potent therapy via lactoferrin and Ti-NPS conjugation. Cisplatinum is a commonly used chemotherapeutic drug; one of the limiting adverse actions of cisplatinum is renal toxicity. Upon cisplatinum administration, autophagy is highly stimulated in the kidney to shield against nephrotoxicity. Atg is a lysosomal degradation process which discards detorirated proteins to retain cell homeostasis. This article summarizes necroptosis progress in reconizing cisplatinum nephrotoxicity and debates how this progress can help in discovering more potent therapy via lactoferrin and Ti-NPS conjugation via monitoring autophagy and apoptotic biomarkers X-box-binding protein 1 (XBP), C/EBP homologous protein (CHOP), hypoxanthine phosphoribosyltransferase-1 (HPRT), FKBP prolyl isomerase 1B (FKBP), Cellular myelocytomatosis oncogene (C-myc), tumor suppressor gene (P53) and tumor necrosis factor (TNF-α). Cisplatinum nephrotoxicity was conducted in rat model via an oral dose of (2 mg/kg BW) for one month furthermore a comparative study was conducted among TiNPs-loaded Cisplatinum and Lactoferrin loaded Cisplatinum. Loaded drug delivery system counteracted Cisplatinum triggered nephrotoxicity via controlling autophagy and apoptotic XBP, CHOP, HPRT, FKBP, C-myc, P53 and TNF-α signaling pathway.

Navigating the complexities of cell death: Insights into accidental and programmed cell death

Cell death is a critical biological phenomenon that can be categorized into accidental cell death (ACD) and programmed cell death (PCD), each exhibiting distinct signaling, mechanistic and morphological characteristics. This paper provides a comprehensive overview of seven types of ACD, including coagulative, liquefactive, caseous, fat, fibrinoid, gangrenous and secondary necrosis, discussing their pathological implications in conditions such as ischemia and inflammation. Additionally, we review eighteen forms of PCD, encompassing autophagy, apoptosis, necroptosis, pyroptosis, paraptosis, ferroptosis, anoikis, entosis, NETosis, eryptosis, parthanatos, mitoptosis, and newly recognized types such as methuosis, autosis, alkaliptosis, oxeiptosis, cuprotosis and erebosis. The implications of these cell death modalities for cellular processes, development, and disease-particularly in the context of neoplastic and neurodegenerative disorders-are also covered. Furthermore, we explore the crosstalk between various forms of PCD, emphasizing how apoptotic mechanisms can influence pathways like necroptosis and pyroptosis. Understanding this interplay is crucial for elucidating cellular responses to stress, as well as for its potential relevance in clinical applications and therapeutic strategies. Future research should focus on clarifying the molecular mechanisms that govern different forms of PCD and their interactions.