Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (178)

Search Parameters:
Keywords = elastase inhibitors

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
12 pages, 9938 KB  
Case Report
Delayed Diagnosis of Alpha-1 Antitrypsin Deficiency in an Elderly Patient
by Beatrice Ragnoli, Patrizia Pochetti, Xheni Veselagu and Mario Malerba
Diagnostics 2026, 16(9), 1329; https://doi.org/10.3390/diagnostics16091329 - 28 Apr 2026
Viewed by 363
Abstract
Background and Clinical Significance: Alpha-1 antitrypsin deficiency (AATD) is an autosomal codominant disorder caused by pathogenic variants in the SERPINA1 gene, resulting in reduced circulating alpha-1 antitrypsin (AAT) or production of dysfunctional protein. AAT is the principal inhibitor of neutrophil elastase, and its [...] Read more.
Background and Clinical Significance: Alpha-1 antitrypsin deficiency (AATD) is an autosomal codominant disorder caused by pathogenic variants in the SERPINA1 gene, resulting in reduced circulating alpha-1 antitrypsin (AAT) or production of dysfunctional protein. AAT is the principal inhibitor of neutrophil elastase, and its deficiency leads to unchecked proteolytic activity, progressive destruction of lung parenchyma, and increased susceptibility to infections. Severe deficiency, particularly in individuals homozygous for the Z allele (PI*ZZ), predisposes to early-onset panacinar emphysema, chronic airflow obstruction, and liver disease. Despite its clinical relevance, AATD remains markedly underdiagnosed and is frequently misclassified as smoking-related chronic obstructive pulmonary disease (COPD), delaying access to disease-modifying therapy, genetic counselling, and preventive strategies. Early recognition is therefore essential to improve outcomes. Case Presentation: We report the case of a 68-year-old ex-smoker with a long-standing diagnosis of “COPD” who presented with acute-on-chronic type 2 respiratory failure and community-acquired pneumonia. Spirometry revealed severe airflow obstruction, and high-resolution computed tomography demonstrated extensive basilar panlobular emphysema, raising suspicion for AATD. Serum AAT concentration was critically low at 26.8 mg·dL−1, and isoelectric focusing confirmed a PI*ZZ phenotype. Next-generation sequencing identified homozygosity for the SERPINA1 c.1096G>A (Z) variant, with no additional pathogenic alleles. Cascade family screening revealed multiple heterozygous PI*MZ relatives. Before augmentation therapy could be initiated, the patient developed severe Legionella pneumophila pneumonia with secondary bacterial superinfection, progressing to refractory septic shock and death. Conclusions: This case illustrates how AATD can masquerade as smoking-related COPD for years, leading to missed opportunities for timely intervention. It underscores the importance of testing all adults with COPD or refractory asthma at least once, regardless of age or smoking history. Early diagnosis enables initiation of augmentation therapy, targeted vaccination, lifestyle modification, and genetic counselling, ultimately improving prognosis and reducing preventable morbidity and mortality. Full article
(This article belongs to the Section Clinical Diagnosis and Prognosis)
Show Figures

Figure 1

19 pages, 2195 KB  
Article
The Differential Redox Resilience of Alvelestat and Sivelestat: A Mechanistic Hypothesis for Inhibitor Performance Under Oxidative Stress
by Maura D’Amato, Pasquale Linciano, Laurent R. Chiarelli, Giampiero Pietrocola, Paolo Iadarola, Simona Collina, Maria Antonietta Grignano, Marilena Gregorini, Teresa Rampino and Simona Viglio
Molecules 2026, 31(9), 1454; https://doi.org/10.3390/molecules31091454 - 28 Apr 2026
Viewed by 484
Abstract
Human neutrophil elastase (HNE) is a key driver of inflammatory lung disorders, promoting extracellular matrix degradation and tissue damage. Although inhibitors such as Sivelestat and Alvelestat are clinically relevant, their performance within the oxidative microenvironment of diseased lungs remains poorly understood. Here, we [...] Read more.
Human neutrophil elastase (HNE) is a key driver of inflammatory lung disorders, promoting extracellular matrix degradation and tissue damage. Although inhibitors such as Sivelestat and Alvelestat are clinically relevant, their performance within the oxidative microenvironment of diseased lungs remains poorly understood. Here, we employed an integrated in vitro and in silico approach to investigate their behavior under physiological and oxidative conditions and to provide a molecular-level interpretation. Under physiological conditions, enzymatic assays and steady-state kinetics confirmed that both compounds act as competitive inhibitors, with Sivelestat displaying higher baseline potency. Under oxidative stress, however, Sivelestat exhibited a marked reduction in inhibitory potency, whereas Alvelestat retained its efficacy. Molecular modeling and molecular dynamics simulations of native and oxidized HNE variants provided a structural rationale for this divergence. Alvelestat, as a non-covalent inhibitor, maintains stable binding despite increased flexibility of the active site, whereas Sivelestat, acting via a reversible covalent mechanism, requires a precise pre-acylation geometry. Oxidation-induced remodeling of the S1 pocket disrupts the near-attack configuration required for covalent bond formation, thereby impairing inhibition. Overall, these findings indicate that oxidative stress may selectively compromise covalent inhibition while preserving enzymatic activity, and suggest that context-dependent redox-related structural effects may represent a consideration for the design of next-generation HNE inhibitors. Full article
(This article belongs to the Special Issue Chemical Biology in Europe)
Show Figures

Graphical abstract

22 pages, 1622 KB  
Review
Human Neutrophil Elastase and the Protein-Storm Axis: Reversible Synthetic Inhibitors in Inflammatory Disease
by Simona Viglio, Maria Antonietta Grignano, Marilena Gregorini, Teresa Rampino, Giampiero Pietrocola and Paolo Iadarola
Molecules 2026, 31(9), 1441; https://doi.org/10.3390/molecules31091441 - 27 Apr 2026
Viewed by 554
Abstract
Human neutrophil elastase (HNE) is a central mediator of neutrophil-driven inflammation. Yet, despite decades of research and drug development, therapies targeting HNE have not consistently translated into clear clinical benefits. We suggest that this translational gap partly arises from how HNE has traditionally [...] Read more.
Human neutrophil elastase (HNE) is a central mediator of neutrophil-driven inflammation. Yet, despite decades of research and drug development, therapies targeting HNE have not consistently translated into clear clinical benefits. We suggest that this translational gap partly arises from how HNE has traditionally been conceptualized, as a single enzyme to inhibit. In biological systems, however, HNE operates within a complex and tightly regulated network of proteases and inflammatory mediators. This network is spatially compartmentalized and strongly influenced by local redox conditions, making HNE activity highly context-dependent. From a systems perspective, HNE acts as an amplifier of inflammation. Its extracellular activity connects several pathological processes, including activation of innate immunity, extracellular matrix degradation, disruption of epithelial and endothelial barriers, and the transition toward chronic inflammation. In this review, we integrate insights from enzymology, systems biology, and clinical research to reassess the development of HNE inhibitors, ranging from endogenous antiproteases to more recent reversible synthetic compounds. Despite their chemical and pharmacological diversity, many of these strategies have encountered similar limitations. We therefore argue that future therapeutic approaches should move beyond the inhibition of HNE as an isolated target and instead aim to modulate the broader protease network, with particular attention to drug–target kinetics and precise delivery to disease-relevant microenvironments. Full article
Show Figures

Graphical abstract

11 pages, 786 KB  
Article
Integration of HPLC-ESI-MS/MS and NMR Techniques for Characterizing Monoterpene Indole Alkaloids in Leaves and Stems of Psychotria densicostata and Their Potential as Inhibitors of Human Neutrophil Elastase
by Virginia G. Correia, Victor F. Jesus, Rodolfo S. Barboza, Alviclér Magalhães, Leonardo N. Seito, Mário Gomes, Marcelo R. R. Tappin and Ligia M. M. Valente
Analytica 2026, 7(2), 31; https://doi.org/10.3390/analytica7020031 - 18 Apr 2026
Viewed by 575
Abstract
The species Psychotria densicostata Müll.Arg. is a shrub belonging to the Rubiaceae family, endemic to Brazil. So far, there are reports neither of phytochemical work on nor of biological evaluation of it. This study investigated its alkaloid profile and evaluated the inhibitory effects [...] Read more.
The species Psychotria densicostata Müll.Arg. is a shrub belonging to the Rubiaceae family, endemic to Brazil. So far, there are reports neither of phytochemical work on nor of biological evaluation of it. This study investigated its alkaloid profile and evaluated the inhibitory effects of extracts, alkaloid-enriched fractions and one of its major constituents on human neutrophil elastase (HNE). The monoterpene indole alkaloids (MIAs) strictosidine (1), (3α,5α)-5-carboxystrictosidine (2), strictosidine lactam (3), lyaloside (4), lyalosidic acid (5), 5-carboxystrictosamide (6), 3,4-dehydrostrictosidinic acid (7), and N-glucopyranosyl vincosamide (8) were characterized in mixture, in its leaves, and/or stems by using an integrated approach combining nuclear magnetic resonance (NMR) techniques, high performance liquid chromatography coupled to a tandem mass spectrometer with an electrospray ionization source (HPLC-ESI-MS/MS), and molecular networks. The crude leaf extract and an alkaloid-enriched fraction derived from it showed inhibitory activity against HNE. These results contribute to the chemical knowledge of the species and suggest its potential biological property. Full article
Show Figures

Figure 1

35 pages, 3865 KB  
Article
In Silico Interaction Profiling of Pseudomonas aeruginosa Elastase (LasB) with Structural Fragments of Synthetic Polymers
by Afrah I. Waheeb, Saleem Obaid Gatia Almawla, Mayada Abdullah Shehan, Sameer Ahmed Awad, Mohammed Mukhles Ahmed and Saja Saddallah Abduljaleel
Appl. Microbiol. 2026, 6(4), 51; https://doi.org/10.3390/applmicrobiol6040051 - 7 Apr 2026
Viewed by 581
Abstract
Background: The ability of synthetic plastics to persist in the environment and the accumulation of microplastics has intensified the need to explore biological mechanisms capable of interacting with, and possibly degrading, polymeric materials. Microbial enzymes that have extensive catalytic flexibility represent promising candidates [...] Read more.
Background: The ability of synthetic plastics to persist in the environment and the accumulation of microplastics has intensified the need to explore biological mechanisms capable of interacting with, and possibly degrading, polymeric materials. Microbial enzymes that have extensive catalytic flexibility represent promising candidates in this context. Aim: This study set out to examine the molecular interaction patterns and dynamical stability of Pseudomonas aeruginosa elastase (LasB) with representative structural fragments of typical synthetic plastics to assess the suitability of the enzyme to polymer-derived substrates. Methods: The crystallographic structure of LasB (PDB ID: 1EZM) was retrieved from the Protein Data Bank and pre-prepared with the help of AutoDock4.2.6 Tools. Those polymer-derived ligands that were associated with the major industrial plastics such as polyamide (PA), polyvinyl chloride (PVC), polycarbonate (PC), poly-ethylene terephthalate (PET), polymethyl methacrylate (PMMA), and polyurethane (PUR) were retrieved in the PubChem database and geometrically optimized with the help of the MMFF94 force field. AutoDock Vina, with a specific grid box around the catalytic pocket, including Zn2+ ion, was used to perform molecular docking simulations. PyMOL and BIOVIA Discovery Studio software were used to analyze binding conformations, interaction residues and types of intermolecular contacts. Phosphoramidon, a known metalloprotease inhibitor, served as a positive control to confirm the docking protocol. Additional assessment of the structural stability and conformational behavior of the enzyme–ligand complexes was conducted by molecular dynamics (MD) simulations with the Desmond engine and explicit solvent model in a 50 ns trajectory using the OPLS4 force field. RMSD, RMSF, radius of gyration, hydrogen bonding analysis and solvent accessibility parameters were used to measure structural stability. Results: The docking experiment showed varying binding affinities with the test polymers. Polycarbonate (−5.774 kcal/mol) and polyurethane (−5.707 kcal/mol) had the highest in-teractions with the LasB catalytic pocket, polyamide (−5.277 kcal/mol) and PET (−4.483 kcal/mol) followed PMMA and PVC, which had weaker affinities. The following were the important residues involved in interaction networks: Glu141, His140, Val137, Arg198, Tyr114, and Trp115 that were implicated in interaction networks with hydrophobic interactions, π-cation interactions and van der Waals forces that were the major stabilization forces. MD simulations had stabilized complexes, and RMSD values were found to be within acceptable ranges of stability, and ligand-specific changes (around 1.0-3.2 A), which is also in line with stable protein-ligand systems. Phosphoramidon used as a positive control had an RMSD of 1.205 A which is within this stability range. PCA determined various ligand-bound conformational states of LasB with PA in com-pact state, PC and PVC in intermediate states and PUR, PMMA and PET in ex-panded conformations, indicating structur-al stability and adaptability of the binding pocket. Conclusion: These findings show that LasB has a structurally flexible catalytic pocket that can accommodate a wide range of polymer-derived ligands. These results offer an insight into the recognition of enzymes with polymers at the molecular level and also indicate that LasB might help in the interaction of microorganisms with synthetic plastics in environmental systems. Full article
Show Figures

Figure 1

17 pages, 3122 KB  
Review
Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease
by Evangelia Fouka, Argyro Vrouvaki, Marina Moustaka Christodoulou, Stelios Loukides and Georgios Hillas
Medicina 2026, 62(4), 639; https://doi.org/10.3390/medicina62040639 - 27 Mar 2026
Viewed by 2049
Abstract
Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by reduced circulating levels and/or impaired function of alpha-1 antitrypsin (AAT), a key serine protease inhibitor, in which loss of effective antiprotease protection results in unchecked neutrophil elastase activity and progressive lung tissue destruction. [...] Read more.
Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by reduced circulating levels and/or impaired function of alpha-1 antitrypsin (AAT), a key serine protease inhibitor, in which loss of effective antiprotease protection results in unchecked neutrophil elastase activity and progressive lung tissue destruction. Although AATD accounts for approximately 1% of chronic obstructive pulmonary disease (COPD) cases and up to 2% of emphysema, AATD-related COPD remains largely underdiagnosed, despite guideline recommendations for systematic evaluation in patients with COPD, particularly in high-risk clinical settings. Pathologically, AATD-related COPD is not limited to the typical early-onset, lower-lobe-predominant emphysema, also including upper-lobe or mixed emphysema patterns, airway-predominant disease, small airways dysfunction, and bronchiectasis. Clinically, AATD-related COPD is distinguished from smoking-related COPD by its earlier onset, physiological impairment that is often disproportionate to smoking exposure, and its potential presence of certain extrapulmonary manifestations. Diagnosis and monitoring are also challenged by the frequent discordance between airflow limitation and gas transfer impairment, as well as the early involvement of small airways, limiting reliance on spirometry alone. A multimodal assessment incorporating more sensitive functional techniques and CT densitometry may provide a more precise evaluation of disease burden, progression, and prognosis. Management generally follows standard COPD principles, with intravenous AAT augmentation therapy remaining currently the only established disease-modifying therapy for selected patients with severe deficiency. The advent of new pharmacological and gene-based therapies emphasizes the importance of developing personalized management strategies that integrate genotype and longitudinal disease behavior. This narrative review summarizes current evidence on AATD-associated COPD, focusing on its genetic basis and pathophysiological features, clinical and functional heterogeneity, current and emerging diagnostic and monitoring approaches, and disease-specific management considerations. Full article
(This article belongs to the Special Issue Advances in Rare Diseases Affecting the Respiratory System)
Show Figures

Figure 1

15 pages, 4740 KB  
Article
Do LRG1–SERPINA1 Interactions Modulate Fibrotic and Inflammatory Signatures in Rheumatoid Arthritis? A Proteomic and In Silico Investigation
by Talib Hussain, Monika Verma and Sagarika Biswas
Pathophysiology 2026, 33(1), 16; https://doi.org/10.3390/pathophysiology33010016 - 6 Feb 2026
Viewed by 848
Abstract
Background: Rheumatoid arthritis (RA) is a systemic, pro-inflammatory, autoimmune disease that mainly affects the joints in a symmetrical manner. Differential proteomic profiling through Sequential Window Acquisition of all Theoretical Fragment Ion Mass Spectra (SWATH-MS/MS) helps in a better understanding of the RA pathogenesis. [...] Read more.
Background: Rheumatoid arthritis (RA) is a systemic, pro-inflammatory, autoimmune disease that mainly affects the joints in a symmetrical manner. Differential proteomic profiling through Sequential Window Acquisition of all Theoretical Fragment Ion Mass Spectra (SWATH-MS/MS) helps in a better understanding of the RA pathogenesis. In this study, we compared the differentially upregulated proteins with those associated with fibrosis to gain a deeper understanding of the fibrotic aspect of RA. Methods: We analyzed plasma proteomics data, previously obtained by SWATH-MS/MS. Our focus was on proteins associated with Leucine Rich Alpha2glycoprotein1 (LRG1) and we employed an in silico method. Results: We identified common proteins between RA and fibrosis. Among them, LRG1 and Serine Protease Inhibitor Clade A, Member 1 (SERPINA1) showed a high co-expression score in the gene clusters. LRG1 is both pro-inflammatory and pro-fibrotic, while SERPINA1 is an anti-inflammatory protein that inhibits pro-inflammatory and pro-fibrotic molecules (Elastase). Further, docking studies and a simulation study of the docked complexes with the analysis of Hydrogen bonds, Solvent Accessible Surface Area (SASA), Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF) and Radius of gyration (Rg), suggested a strong interaction between the two partners, LRG1 and SERPINA1. Conclusions: Our study suggests that LRG1 may inhibit SERPINA1 and promote inflammation and fibrotic processes by disrupting SERPINA1’s primary function. Full article
Show Figures

Figure 1

15 pages, 308 KB  
Review
Brensocatib—Another Therapeutic “Window of Opportunity” for Patients with Bronchiectasis
by Florin-Dumitru Mihălțan, Ruxandra Ulmeanu and Ancuța-Alina Constantin
J. Clin. Med. 2026, 15(3), 1257; https://doi.org/10.3390/jcm15031257 - 4 Feb 2026
Viewed by 1715
Abstract
Introduction: Bronchiectasis is a chronic, heterogeneous airway disease characterised by irreversible bronchial dilatation, recurrent infections, and persistent inflammation, leading to progressive lung damage, frequent exacerbations, and impaired quality of life. Neutrophil-driven inflammation, largely mediated by excessive activity of neutrophil serine proteases such as [...] Read more.
Introduction: Bronchiectasis is a chronic, heterogeneous airway disease characterised by irreversible bronchial dilatation, recurrent infections, and persistent inflammation, leading to progressive lung damage, frequent exacerbations, and impaired quality of life. Neutrophil-driven inflammation, largely mediated by excessive activity of neutrophil serine proteases such as neutrophil elastase, represents a central pathogenic mechanism and an important therapeutic target. Methods: Brensocatib, a first-in-class, selective, and reversible inhibitor of dipeptidyl peptidase-1 (DPP-1), prevents the activation of neutrophil serine proteases during neutrophil maturation in the bone marrow. By reducing downstream protease activity, brensocatib modulates aberrant neutrophilic inflammation without broadly suppressing immune function. Results: Clinical studies, including the Phase-2 WILLOW trial and the Phase-3 ASPEN trial, have demonstrated that brensocatib significantly reduces exacerbation frequency, prolongs time to first exacerbation, and lowers sputum neutrophil protease activity, with a favourable safety profile. Importantly, these benefits were observed across multiple patient subgroups and in addition to standard-of-care therapies. Conclusions: As the first FDA-approved (12 August 2025) mechanism-based therapy for non–cystic fibrosis bronchiectasis, brensocatib represents a paradigm shift toward targeted, precision treatment of neutrophil-mediated airway disease. Its clinical efficacy, biomarker-driven rationale, and potential to reduce antibiotic dependence highlight brensocatib as a cornerstone therapy in bronchiectasis management and a promising strategy for other neutrophil-driven inflammatory conditions. Full article
(This article belongs to the Special Issue Advances in Pulmonary Disease Management and Innovation in Treatment)
31 pages, 5359 KB  
Article
Rational Design and Virtual Screening of Antimicrobial Terpene-Based Leads from Marrubium vulgare Essential Oil: Structure-Based Optimization for Food Preservation and Safety Applications
by Ahmed Bayoudh, Nidhal Tarhouni, Raoudha Sadraoui, Bilel Hadrich, Alina Violeta Ursu, Guillaume Pierre, Pascal Dubessay, Philippe Michaud and Imen Kallel
Foods 2026, 15(3), 541; https://doi.org/10.3390/foods15030541 - 4 Feb 2026
Viewed by 1090
Abstract
Pseudomonas aeruginosa elastase LasB accelerates refrigerated food spoilage through proteolytic degradation of muscle and milk proteins. While Marrubium vulgare essential oil terpenes exhibit antimicrobial activity, their weak potency and nonspecificity limit direct food preservation applications. This computational study aimed to rationally redesign terpene [...] Read more.
Pseudomonas aeruginosa elastase LasB accelerates refrigerated food spoilage through proteolytic degradation of muscle and milk proteins. While Marrubium vulgare essential oil terpenes exhibit antimicrobial activity, their weak potency and nonspecificity limit direct food preservation applications. This computational study aimed to rationally redesign terpene scaffolds into predicted selective LasB inhibitors. A virtual library of 635 terpene–peptide–phosphinic acid hybrids (expanded to 3940 conformers) was evaluated using consensus molecular docking (Glide/Flare) against LasB (PDB: 3DBK) and three human off-target proteases. Top candidates underwent duplicate 150 ns molecular dynamics simulations with MM/GBSA binding free-energy calculations. Computational screening identified thymol–Leu–Trp–phosphinic acid as the lead candidate with predicted binding affinity of −12.12 kcal/mol, comparable to reference inhibitor phosphoramidon (−11.87 kcal/mol), and predicted selectivity index of +0.12 kcal/mol representing a 2.3 kcal/mol advantage over human proteases. Molecular dynamics simulations indicated exceptional stability (98.7% stable frames, 0.12 Å inter-replica RMSD) with consistent zinc coordination. Structure–activity analysis revealed phosphinic zinc-binding groups (+1.57 kcal/mol), Leu–Trp linkers (+2.47 kcal/mol), and phenolic scaffolds (+1.35 kcal/mol) as predicted optimal structural features. This in silico study provides a computational framework and prioritized candidate set for developing natural product-derived food preservatives. All findings represent computational predictions requiring experimental validation through enzymatic assays, food model studies, and toxicological evaluation. Full article
Show Figures

Figure 1

17 pages, 520 KB  
Article
Genetic Analysis of Virulence and β-Lactamase Determinants Related to β-Lactamase Inhibitors in Pseudomonas aeruginosa Strains from Nosocomial Infections
by Gloria Luz Paniagua-Contreras, Elizabeth Olvera-Navarro, Jennefer Paloma Herrera-Gabriel, Laura Verónica González-Vega, Luis Rey García-Cortés, Moisés Moreno-Noguez, Héctor Martínez-Gregorio, Felipe Vaca-Paniagua, Ana María Fernández-Presas and Eric Monroy-Pérez
Antibiotics 2026, 15(1), 16; https://doi.org/10.3390/antibiotics15010016 - 22 Dec 2025
Viewed by 1029
Abstract
Background/Objectives: The emergence of hypervirulent Pseudomonas aeruginosa strains resistant to β-lactamase inhibitor antibiotics is a critical health problem as they impede the treatment of infections. The objective of this study was to determine the different molecular arrangements of the virulence genotype related [...] Read more.
Background/Objectives: The emergence of hypervirulent Pseudomonas aeruginosa strains resistant to β-lactamase inhibitor antibiotics is a critical health problem as they impede the treatment of infections. The objective of this study was to determine the different molecular arrangements of the virulence genotype related to β-lactamase genotype and the resistance phenotype to a combination of β-lactam antibiotics and β-lactamase inhibitors, and the phylogroups in P. aeruginosa strains isolated from patients with healthcare-associated infections and community-acquired infections. Methods: P. aeruginosa, virulence genes, β-lactamase genes and phylogroups were identified using polymerase chain reaction. Resistance to β-lactam antibiotics and β-lactamase inhibitors was determined using the disk diffusion method. The MIC determination of ticarcillin/clavulanic acid and piperacillin/tazobactam was performed using the MIC test strip for antimicrobial susceptibility testing. Results: In total, 124 P. aeruginosa strains from patients with healthcare-associated (67/124) and community-acquired infections (57/124) were analyzed. Most strains from patients with healthcare-associated infections and community-acquired infections harbored genes for proteases (aprA), phospholipases (pIcH and pIcN), elastases (lasA and lasB), rhamnolipids (rhLA), quorum-sensing system (lasI and rhII), and β-lactamase (blaoxa-4, blaoxa-1, and blaGES). In total, 100% (124/124) and 99.1% (123/124) of the strains isolated from patients with healthcare-associated and community-acquired infections were resistant to the β-lactamase inhibitor antibiotics, amoxicillin/clavulanic acid and ampicillin/sulbactam, respectively, while 54% (67/124) of the strains were resistant to piperacillin/tazobactam. Phylogroup 1 (22/124) was detected more frequently among the strains in relation to phylogroup 2 (8/12). Conclusions: We demonstrated different association profiles of virulence genotype related to the β-lactamase genotype, the β-lactamase inhibitor resistome, phylogroups, and clinical origin of the strains. Therefore, medical treatment regimens against infections caused by P. aeruginosa should be improved. Full article
(This article belongs to the Special Issue Antibiotic Resistance in Hospital-Acquired Infections)
Show Figures

Figure 1

21 pages, 5282 KB  
Article
Emodin as a Broad-Spectrum Inhibitor of QS-Regulated Pathogenicity and Biofilms: A Non-Antibiotic Strategy Against Microbial Virulence
by Fareha Bano
Micro 2025, 5(4), 56; https://doi.org/10.3390/micro5040056 - 5 Dec 2025
Viewed by 872
Abstract
Antimicrobial resistance (AMR) poses a global health threat, which is becoming more challenging due to the involvement of bacterial virulence mechanisms such as quorum sensing (QS) and biofilm formation. These systems regulate pathogenic traits and shield bacteria from conventional therapies. Phytocompounds offer promising [...] Read more.
Antimicrobial resistance (AMR) poses a global health threat, which is becoming more challenging due to the involvement of bacterial virulence mechanisms such as quorum sensing (QS) and biofilm formation. These systems regulate pathogenic traits and shield bacteria from conventional therapies. Phytocompounds offer promising antivirulence strategies by disrupting QS and biofilms without exerting selective pressure. In this study, emodin, a natural anthraquinone, was evaluated for its anti-QS and antibiofilm efficacy. Emodin inhibited violacein production by 63.86% in C. violaceum 12472. In P. aeruginosa PAO1, it suppressed pyocyanin (68.04%), pyoverdin (48.79%), exoprotease (58.55%), elastase (43.13%), alginate (74.12%), and rhamnolipids (56.37%). In S. marcescens MTCC 97, emodin reduced prodigiosin (55.94%), exoprotease (48.80%), motility (83.27%), and cell surface hydrophilicity (41.20%). Biofilm formation was inhibited by over 50% in all three bacteria, highlighting emodin’s potential as a broad-spectrum antibiofilm agent. Molecular docking analyses indicated that emodin exhibited affinity towards QS regulatory proteins CviR, LasR, and SmaR, implying a possible competitive interaction at their ligand-binding sites. Subsequent molecular dynamics simulations confirmed these observations by demonstrating structural stability in emodin-bound proteins. The collective insights from in vitro assays and computational studies underscore the potential of emodin in interfering with QS-mediated virulence expression and biofilm development. Such findings support the exploration of non-antibiotic QS inhibitors as therapeutic alternatives for managing bacterial infections and reducing dependence on traditional antimicrobial agents. Full article
Show Figures

Figure 1

28 pages, 1699 KB  
Review
The Role of Extracellular Proteases and Extracellular Matrix Remodeling in the Pre-Metastatic Niche
by Gillian C. Okura, Alamelu G. Bharadwaj and David M. Waisman
Biomolecules 2025, 15(12), 1696; https://doi.org/10.3390/biom15121696 - 5 Dec 2025
Cited by 3 | Viewed by 1914
Abstract
The premetastatic niche (PMN) represents a specialized microenvironment established in distant organs before the arrival of metastatic cells. This concept has fundamentally altered our understanding of cancer progression, shifting it from a random event-driven process to an orchestrated one. This review examines the [...] Read more.
The premetastatic niche (PMN) represents a specialized microenvironment established in distant organs before the arrival of metastatic cells. This concept has fundamentally altered our understanding of cancer progression, shifting it from a random event-driven process to an orchestrated one. This review examines the critical role of extracellular proteases in PMN formation, focusing on matrix metalloproteinases (MMPs), serine proteases, and cysteine cathepsins that collectively orchestrate extracellular matrix remodeling, immune modulation, and vascular permeability changes essential for metastatic colonization. Key findings demonstrate that MMP9 and MMP2 facilitate basement membrane degradation and the recruitment of bone marrow-derived cells. At the same time, tissue inhibitor of metalloproteinase-1 (TIMP-1) promotes organ-specific hepatic PMN recruitment through neutrophil recruitment mechanisms. The plasminogen–plasmin system emerges as a master regulator through its broad-spectrum proteolytic activity and ability to activate downstream proteases, with S100A10-mediated plasmin generation providing mechanistic pathways for remote PMN conditioning. Neutrophil elastase and cathepsin G contribute to the degradation of anti-angiogenic proteins, thereby creating pro-metastatic microenvironments. These protease-mediated mechanisms represent the earliest interventional window in metastatic progression, offering therapeutic potential to prevent niche formation rather than treat established metastases. However, significant methodological challenges remain, including the need for organ-specific biomarkers, improved in vivo methods for measuring protease activity, and a better understanding of temporal PMN dynamics across different target organs. Full article
(This article belongs to the Section Biological Factors)
Show Figures

Figure 1

18 pages, 2638 KB  
Article
Repurposing MK-8245 as a Quorum Sensing Inhibitor to Suppress Virulence and Potentiate Antibiotic Activity in Pseudomonas aeruginosa
by Giulia Bernabè, Giovanni Marzaro, Mahmoud Elsayed Mosaad Shalata, Daniela Iosob, Valentina Inglima, Massimo Bellato, Ignazio Castagliuolo and Paola Brun
Antibiotics 2025, 14(11), 1116; https://doi.org/10.3390/antibiotics14111116 - 5 Nov 2025
Cited by 3 | Viewed by 1510
Abstract
Background/Objectives: The rise in multidrug-resistant pathogens such as Pseudomonas aeruginosa (PA), coupled with declining antibiotic development, underscores the need for innovative therapeutic strategies. Repurposing approved drugs provides advantages of safety and rapid development. Since quorum sensing (QS) controls key virulence traits in [...] Read more.
Background/Objectives: The rise in multidrug-resistant pathogens such as Pseudomonas aeruginosa (PA), coupled with declining antibiotic development, underscores the need for innovative therapeutic strategies. Repurposing approved drugs provides advantages of safety and rapid development. Since quorum sensing (QS) controls key virulence traits in PA, targeting this pathway represents a promising antivirulence approach. This study aimed to identify and repurpose existing drugs as QS inhibitors. Methods: An in silico docking screen of 3000 FDA-approved or clinically tested compounds was performed against the C4-HSL receptor RhlR. Seventeen candidates were tested in the laboratory strain PAO1 for lactone-dependent signaling inhibition. The most active compound, MK-8245, was further evaluated for effects on growth, cytotoxicity, lactone release, biofilm formation, pyocyanin, elastase, rhamnolipids, and swarming motility. Its activity was also assessed in 20 clinical PA isolates. Results: MK-8245 (40 µM) reduced QS-regulated gene expression by ~60% without affecting viability. In PAO1, it inhibited rhamnolipids (60%), pyocyanin (40%), elastase (25%), biofilm formation, and swarming motility (25%). MK-8245 also enhanced the efficacy of imipenem against biofilms. In clinical isolates, it consistently decreased lactone release (~60%), pyocyanin (~50%), rhamnolipids (~40%), biofilm formation (~30%), and swarming motility (~25%). Conclusions: MK-8245 emerges as a promising antivirulence candidate against P. aeruginosa. By disrupting QS signaling and impairing multiple virulence factors, it attenuates pathogenicity without bactericidal pressure. Its synergy with standard antibiotics and consistent activity in clinical isolates highlight its translational potential and warrant further preclinical evaluation. Full article
(This article belongs to the Special Issue New Inhibitors for Overcoming Antimicrobial Resistance)
Show Figures

Figure 1

27 pages, 2444 KB  
Review
The Role of Neutrophil Extracellular Networks in Cardiovascular Pathology
by Zofia Szymańska, Antoni Staniewski, Michał Karpiński, Katarzyna Zalewska, Oliwia Kalus, Zofia Gramala, Joanna Maćkowiak, Sebastian Mertowski, Krzysztof J. Filipiak, Mansur Rahnama-Hezavah, Ewelina Grywalska and Tomasz Urbanowicz
Cells 2025, 14(19), 1562; https://doi.org/10.3390/cells14191562 - 8 Oct 2025
Cited by 9 | Viewed by 3151
Abstract
Cardiovascular diseases (CVDs) are increasingly being defined not only in terms of metabolic or purely vascular disorders, but also as complex immunometabolic disorders. One of the most groundbreaking discoveries in recent years is the role of neutrophil extracellular networks (NETs/NENs) as a key [...] Read more.
Cardiovascular diseases (CVDs) are increasingly being defined not only in terms of metabolic or purely vascular disorders, but also as complex immunometabolic disorders. One of the most groundbreaking discoveries in recent years is the role of neutrophil extracellular networks (NETs/NENs) as a key link between chronic vascular wall inflammation and thrombotic processes. In this article, we present a synthetic overview of the latest data on the biology of NETs/NENs and their impact on the development of atherosclerosis, endothelial dysfunction, and the mechanisms of immunothrombosis. We highlight how these structures contribute to the weakening of atherosclerotic plaque stability, impaired endothelial barrier integrity, platelet activation, and the initiation of the coagulation cascade. We also discuss the modulating role of classic risk factors such as hypertension, dyslipidemia, and exposure to tobacco smoke, which may increase the formation or hinder the elimination of NETs/NENs. We also focus on the practical application of this knowledge: we present biomarkers associated with the presence of NETs/NENs (cfDNA, MPO–DNA complexes, CitH3, NE), which may be useful in diagnostics and risk stratification, and we discuss innovative therapeutic strategies. In addition to classic methods for indirectly inhibiting NET/NEN formation (antiplatelet, anti-inflammatory, and immunometabolic agents), we present experimental approaches aimed at their neutralization and removal (e.g., DNase I, elastase, and myeloperoxidase inhibitors). We pay particular attention to the context of cardiac and cardiac surgical procedures (Percutaneous Coronary Intervention-PCI, coronary artery bypass grafting-CABG), where rapid NET/NEN bursts can increase the risk of acute thrombotic complications. The overall evidence indicates that NETs/NENs represent an innovative and promising research and therapeutic target, allowing us to view cardiovascular diseases in a new light—as a dynamic interaction of inflammatory, atherosclerotic, and thrombotic processes. This opens up new possibilities in diagnostics, combination treatment and personalisation of therapy, although further research and standardization of detection methods remain necessary. Full article
(This article belongs to the Special Issue Immunoregulation in Cardiovascular Disease)
Show Figures

Figure 1

25 pages, 3037 KB  
Article
Bioactive Potential of Nepenthes miranda Flower Extracts: Antidiabetic, Anti-Skin Aging, Cytotoxic, and Dihydroorotase-Inhibitory Activities
by Kuan-Ming Lai, Yen-Hua Huang, Yi Lien and Cheng-Yang Huang
Plants 2025, 14(16), 2579; https://doi.org/10.3390/plants14162579 - 19 Aug 2025
Viewed by 1598
Abstract
Carnivorous plants have garnered attention as sources of pharmacologically active compounds, yet their floral tissues remain largely underexplored. In this study, we investigated the bioactive properties of Nepenthes miranda flower extracts prepared using water, methanol, ethanol, and acetone. Among these, the ethanol extract [...] Read more.
Carnivorous plants have garnered attention as sources of pharmacologically active compounds, yet their floral tissues remain largely underexplored. In this study, we investigated the bioactive properties of Nepenthes miranda flower extracts prepared using water, methanol, ethanol, and acetone. Among these, the ethanol extract exhibited the highest total phenolic content (18.2 mg GAE/g), flavonoid content (68.9 mg QUE/g), and antioxidant activity (DPPH IC50 = 66.9 μg/mL), along with strong antibacterial effects against Escherichia coli and Staphylococcus aureus. Cosmetically relevant enzyme inhibition assays revealed significant activity against tyrosinase (IC50 = 48.58 μg/mL), elastase (IC50 = 1.77 μg/mL), and hyaluronidase (IC50 = 7.33 μg/mL), supporting its potential as an anti-skin aging agent. For antidiabetic evaluation, the ethanol extract demonstrated potent α-glucosidase inhibition (IC50 = 24.53 μg/mL), outperforming standard inhibitors such as acarbose and quercetin. The extract also displayed marked cytotoxicity against A431 epidermoid carcinoma cells (IC50 = 90.61 μg/mL), inducing dose-dependent apoptosis, inhibiting cell migration and colony formation, and causing significant DNA damage as shown by comet assay. Furthermore, the ethanol extract strongly inhibited the activity of purified human dihydroorotase (IC50 = 25.11 μg/mL), indicating that disruption of pyrimidine biosynthesis may underlie its anticancer activity. Overall, this study provides the first characterization of N. miranda flower extracts, particularly the ethanol fraction, as a promising source of multifunctional bioactive compounds with possible applications in cosmetics, antidiabetic therapy, and cancer treatment. Full article
(This article belongs to the Section Phytochemistry)
Show Figures

Figure 1

Back to TopTop