Search Results (89)

Alzheimer’s disease is a complex neurodegenerative condition characterized by progressive cognitive decline, neuroinflammation, metabolic dysregulation, and abnormal protein deposition. While genetic factors and amyloid-beta-focused hypotheses have been extensively investigated, they fail to fully account for the prolonged prodromal phase or the early susceptibility of olfactory and limbic regions. Emerging evidence suggests chronic peripheral and mucosal infections may influence disease risk; however, mechanisms by which microbial activity outside the central nervous system contributes to persistent neuropathology remain poorly understood. This review explores the emerging concept that bacterial outer membrane vesicles act as mobile, lipid-rich vectors linking peripheral microbial reservoirs to neuroimmune and metabolic dysfunction in the aging brain. We discuss evidence suggesting vesicles originating from oral, olfactory, and upper airway niches can access the central nervous system via vascular routes and direct neural pathways, including olfactory and trigeminal nerves, where they influence glial and endothelial cell function. We also propose the Accumulative Vesicle Load Hypothesis, which describes how cumulative lifetime exposure to bacterial vesicles shapes disease onset, anatomical vulnerability, and progression, and incorporates components of other hypotheses proposed for Alzheimer’s disease. This offers a system-level perspective for early diagnosis and upstream therapeutic strategies, including minimally invasive vesicle profiling in nasal fluid, saliva, blood, and cerebrospinal fluid. This work is a conceptual review that summarizes current evidence in a hierarchically organized manner and proposes a testable model; it does not assert causality where direct human evidence is currently limited. Full article

Serratia marcescens is a highly adaptable Gammaproteobacterium with broad ecological distribution and growing clinical importance. Advances in whole-genome sequencing (WGS) and pangenome analysis reveal extensive genomic plasticity, driven by mobile genetic elements (MGEs) such as plasmids, transposons, integrons, prophages, and extracellular vesicles, which collectively accelerate virulence and antimicrobial resistance (AMR) evolution. S. marcescens displays a dynamic accessory genome enriched in resistance and virulence determinants, supporting persistence in diverse environments, including hospital water systems. Clinically, S. marcescens is an emerging opportunistic pathogen associated with severe healthcare-associated infections, ICU outbreaks, and multidrug-resistant “superbug” phenotypes. Its resistome includes intrinsic AmpC β-lactamase, broad efflux systems, and chromosomal determinants conferring resistance to β-lactams, polymyxins, and multiple additional drug classes, while acquired ESBLs and carbapenemases urther limit therapeutic options. Integrating genomic, evolutionary, and clinical insights underscores the urgent need for improved surveillance, mechanistic understanding, and targeted interventions against carbapenem-resistant S. marcescens (CRSM). Full article

Alzheimer’s (AD) and Parkinson’s disease (PD) are prominent neurodegenerative disorders characterized by early synaptic loss, which correlates more closely with clinical symptoms than neuronal death. This synaptic impairment is primarily driven by disruptions in synaptic vesicle (SV) trafficking, a critical process for maintaining synaptic integrity through a tightly regulated cycle involving clustering, docking-priming, Ca²⁺-triggered fusion, and endocytosis. In AD, amyloid-β (Aβ) oligomers interfere with SNARE-mediated fusion and endocytosis, while hyperphosphorylated tau obstructs vesicle mobility and docking, resulting in cumulative toxicity that aggravates SV defects. Conversely, in PD, α-synuclein (α-syn) aggregation alters vesicle clustering, membrane fusion, and recycling, and these effects are further influenced by Leucine-rich repeat kinase 2 (LRRK2)-Rab-related trafficking defects and the selective vulnerability of dopaminergic terminals. Different from previous reviews that address synaptic dysfunction in a broader manner, the present review is specifically organized around the SV trafficking cycle and compares both shared presynaptic endpoints and disease-specific upstream mechanisms in AD and PD. In addition, recent mechanism-oriented therapeutic strategies are summarized. This vesicle-cycle-centered perspective may provide a clearer framework for understanding presynaptic pathology and for guiding the development of earlier and more targeted interventions. Full article

Intracellular transport is essential for cellular organization and function. This process is driven by molecular motors that ferry cargo along microtubules, but is characterized by intermittent motility, where cargoes switch between directed runs and prolonged pauses. The fundamental nature of these pauses has remained a mystery, specifically whether they are periods of motor detachment and passive drifting or states of active motor engagement. By combining single-particle tracking with large-scale motion analysis, we discovered that pauses are not passive. Instead, they are active, motor-driven states. We uncovered a unifying quantitative law: the diffusivity of a vesicle during a pause scales with the square of its velocity during a run. This parabolic relationship, D_eff ∝ v², holds true for both kinesin and dynein motors, different cargo types, and a variety of cellular perturbations. We show that this coupling arises because the number of engaged motors governs motility in both states. When we reduce motor engagement, vesicles move more slowly and become trapped in longer, less mobile pauses, collectively causing them to fail to reach their destination. Our work redefines transport pauses as an essential, motor-driven part of microtubule-based cargo delivery, revealing a quantitative principle that contributes to robust cargo transport through the crowded cellular environment. Full article

Klebsiella oxytoca has emerged as an important opportunistic pathogen in nosocomial infections, particularly during the COVID-19 pandemic, due to its capacity to acquire and disseminate resistance and virulence genes through horizontal gene transfer (HGT). This study presents a genome-based comparative analysis of K. oxytoca within the genus Klebsiella, aimed at exploring the evolutionary plausibility of outer membrane vesicle (OMV) associated processes in bacterial adaptation. Using publicly available reference genomes, we analyzed pangenome structure, phylogenetic relationships, and the distribution of mobile genetic elements, resistance determinants, virulence factors, and genes related to OMV biogenesis. Our results reveal a conserved set of envelope associated and stress responsive genes involved in vesiculogenic pathways, together with an extensive mobilome and resistome characteristic of the genus. Although these genomic features are consistent with conditions that may favor OMV production, they do not constitute direct evidence of functional OMV mediated horizontal gene transfer. Instead, our findings support a hypothesis generating evolutionary framework in which OMVs may act as a complementary mechanism to established gene transfer routes, including conjugation, integrative mobile elements, and bacteriophages. Overall, this study provides a genomic framework for future experimental and metagenomic investigations into the role of OMV-associated processes in antimicrobial resistance dissemination and should be interpreted as a recently identified evolutionary strategy inferred from genomic data, rather than a novel or experimentally validated mechanism. Full article

Background/Objectives: Rotavirus remains a major cause of severe acute gastroenteritis in infants worldwide. The suboptimal efficacy of current vaccines underscores the need for alternative microbiome-based interventions, including postbiotics. Extracellular vesicles (EVs) from probiotic and commensal E. coli strains have been shown to mitigate diarrhea and enhance immune responses in a suckling-rat model of rotavirus infection. Here, we investigate the regulatory mechanisms activated by EVs in rotavirus-infected enterocytes. Methods: Polarized Caco-2 monolayers were used as a model of mature enterocytes. Cells were pre-incubated with EVs from the probiotic E. coli Nissle 1917 (EcN) or the commensal EcoR12 strain before rotavirus infection. Intracellular Ca²⁺ concentration, ROS levels, and the expression of immune- and barrier-related genes and proteins were assessed at multiple time points post-infection. Results: EVs from both strains exerted broad protective effects against rotavirus-induced cellular dysregulation, with several responses being strain-specific. EVs interfered with viral replication by counteracting host cellular processes essential for rotavirus propagation. Specifically, EV treatment significantly reduced rotavirus-induced intracellular Ca²⁺ mobilization, ROS production, and COX-2 expression. In addition, both EV types reduced virus-induced mucin secretion and preserved tight junction organization, thereby limiting viral access to basolateral coreceptors. Additionally, EVs enhanced innate antiviral defenses via distinct, strain-dependent pathways: EcN EVs amplified IL-8-mediated responses, whereas EcoR12 EVs preserved the expression of interferon-related signaling genes. Conclusions: EVs from EcN and EcoR12 act through multiple complementary mechanisms to restrict rotavirus replication, spread, and immune evasion. These findings support their potential as effective postbiotic candidates for preventing or treating rotavirus infection. Full article

Magnetosomes are organelle-like structures within magnetotactic bacteria that store iron biominerals in membrane-bound vesicles. In bacteria, formation of these structures is highly regulated by approximately 30 genes, which are conserved throughout different species. To compartmentalize iron in mammalian cells and provide gene-based contrast for magnetic resonance imaging, we introduced key magnetosome proteins. The expression of essential magnetosome genes mamI and mamL as fluorescent fusion proteins in a human melanoma cell line confirmed their co-localization and interaction. Here, we investigate the expression of two more essential magnetosome genes, mamB and mamE, using confocal microscopy to describe fluorescent fusion protein expression patterns and analyze the observed intracellular mobility. Custom software was developed to characterize fluorescent particle trajectories. In mammalian cells, essential magnetosome proteins display different diffusive behaviours. However, all magnetosome proteins travelled at similar velocities when interacting with mammalian mobile elements, suggesting that MamL, MamL + MamI, MamB, and MamE interact with similar molecular motor proteins. These results confirm that localization and interaction of essential magnetosome proteins are feasible within the mammalian intracellular compartment. Full article

Lipid vesicles and related nanocarriers often contain two compartments, such as the inner and outer leaflets of a bilayer membrane between which amphipathic molecules can migrate. We develop a stochastic model for describing the transfer kinetics of cargo between the two compartments in an ensemble of carriers, neglecting inter-carrier exchange to focus exclusively on intra-carrier redistribution. Starting from a set of rate equations, we examine the Gaussian regime in the limit of low cargo occupation where Gaussian and Poissonian statistics overlap. We derive a Fokker–Planck equation that we solve analytically for any initial cargo distribution among the carriers. Moments of the predicted distributions and examples, including a comparison between numerical solutions of the rate equations and analytic solutions of the Fokker–Planck equation, are presented and discussed, thereby establishing a theoretical foundation to study coupled intra- and inter-carrier transport processes in mobile nanocarrier systems. Full article

Background/Objectives: Olive leaf (Olea europaea L.), a by-product of olive oil production, is rich in bioactive phenolics but limited in application due to poor solubility and stability. To improve their bioavailability, this study presents a comparative encapsulation strategy using three phospholipid-based liposomal systems (AL, PG90, and PH90) loaded with ethanolic olive leaf extract. Methods: Liposomes were characterized by physicochemical parameters, encapsulation efficiency (EE), antioxidant activity, morphology, release kinetics under simulated physiological conditions, and 60-day stability. To the best of our knowledge, this is the first direct comparison of AL, PG90, and PH90 matrices for olive leaf extract encapsulation. Results: HPLC and GC-MS confirmed successful encapsulation, with oleuropein showing the highest EE (up to 76.18%). PH90 favored retention of non-polar triterpenes, while AL and PG90 preferentially encapsulated polar flavonoid glycosides. FT-IR analysis verified extract integration into phospholipid bilayers. Antioxidant activity remained high in all loaded formulations, with negligible activity in empty liposomes. Extract-loaded systems exhibited reduced particle size, higher viscosity, and more negative electrophoretic mobility, enhancing colloidal stability. PG90 liposomes displayed the most stable mobility profile over 60 days. Transmission electron microscopy and nanoparticle tracking analysis revealed formulation-dependent vesicle morphology and concentration profiles. Release studies demonstrated significantly prolonged polyphenol diffusion from PG90 liposomes compared to the free extract. Conclusions: Phospholipid composition critically governs encapsulation selectivity, stability, and release behavior. Tailored liposomal systems offer a promising strategy to enhance the stability and delivery of olive leaf polyphenols, supporting their application in bioactive delivery platforms. Full article

Background/Objectives: In the present study, ergosterol, a novel natural and animal-free alternative sterol, was investigated, and its effects on liposomal properties were assessed. Importantly, ergosterol’s fungal origin offers a sustainable substitute for cholesterol, aligning with current trends in natural and vegan-friendly formulations. Methods: This study explored the effect of ergosterol content (10 mol% vs. 20 mol%) on the encapsulation efficiency (EE), physical properties, morphology, antioxidant activity, lipid peroxidation, and storage stability of Serpylli herba extract-loaded liposomes. Results: Liposomes with 20 mol% ergosterol exhibited significantly higher EE (~81.0%) than those with 10 mol% (~75.6%), along with improved resistance to UV- and freeze-drying-induced reduction in EE. Extract loading resulted in a reduced particle size, indicating favorable bilayer interactions, whereas lyophilization increased size and polydispersity, reflecting structural destabilization. However, 20 mol% ergosterol improved vesicle uniformity and surface charge stability, suggesting enhanced bilayer rigidity. Zeta potential and mobility trends supported improved colloidal stability in ergosterol-enriched systems under all tested conditions. Over 28 days at 4 °C, non-treated extract-loaded liposomes with a higher ergosterol content demonstrated enhanced vesicle integrity. During storage, UV-treated and lyophilized liposomes with 20 mol% ergosterol maintained more consistent size and charge profiles, indicating better membrane reorganization and stability. Nanoparticle tracking analysis demonstrated that ergosterol content modulates vesicle concentration in a dose-dependent manner, highlighting the role of membrane composition in liposome formation and potential dose uniformity. Transmission electron microscopy analysis of extract-loaded liposomes demonstrated well-defined vesicles with intact structural features. A study in a Franz diffusion cell revealed that ergosterol-enriched liposomes significantly delayed polyphenol release compared to free extract, confirming their potential for controlled delivery. Antioxidant activity was preserved in all liposomal systems, with higher ergosterol content supporting improved ABTS radical scavenging potential after stress treatments. FRAP assay results remained stable across formulations, with no major differences between sterol levels. TBARS analysis demonstrated that Serpylli herba extract significantly reduced UV-induced lipid peroxidation in ergosterol-enriched liposomes, underscoring its protective antioxidant role. Conclusions: Higher ergosterol content enhanced liposomal performance in terms of encapsulation, structural resilience, and antioxidant retention, particularly under UV and lyophilization stress. Ergosterol-containing liposomes exhibited improved stability, favorable particle size distribution, and high encapsulation efficiency, while maintaining the antioxidant functionality of the incorporated Serpylli herba polyphenol-rich extract. These findings highlight the potential of ergosterol-based liposomes as robust carriers for bioactive compounds in pharmaceutical and nutraceutical applications that align with current trends in green and vegan-friendly formulations. Full article

Extracellular vesicles (EVs) express features of parental cells and are fundamental in modulating the crosstalk between cancer cells and their environment. Increasing evidence suggests that EVs have a pivotal role in tumorigenesis, cancer development, and drug resistance. EVs are also involved in controlling the communication between hematopoietic stem cells and the surrounding microenvironment in the bone marrow (BM), during several processes such as self-renewal, mobilization, and lineage differentiation. Proteins expressed in cancer cell-derived EVs can be useful to further understand the regulation of hematopoietic stem cell fate, a fundamental mechanism in acute myeloid leukemia (AML). Furthermore, EVs are implicated in transmitting drug-resistance mechanisms in solid and not-solid cancer types. Here, using a proteomic approach, we analyze and validate the protein profile of EVs from three AML cell lines with different genotypes, namely OCI-AML-2, OCI-AML-3, and HL-60. The majority of the identified proteins were significantly enriched in the Gene Ontology category ‘Extracellular Exosome’. Network model analysis of EV proteins revealed several significantly modulated pathways, including inflammation activation and metastatic processes in AML cell-derived EVs. The EVs proteomic profiling allows us to identify the EVs-associated molecules and pathways that could impact cancer progression and drug resistance. Full article

Antibiotics are widely used in modern medicine. However, as global antibiotic consumption rises, environmental contamination with antibiotics and antibiotic resistance genes (ARGs) is becoming a serious concern. The impact of antibiotic use on human health is now under scrutiny, particularly regarding the emergence of antibiotic-resistant bacteria (ARB) in the environment. This has heightened interest in technologies for treating ARGs, highlighting the need for effective solutions. This review traces the life cycle of ARB and ARGs driven by human activity, revealing pathways from antibiotic use to human infection. We address the mechanisms enabling resistance in ARB during this process. Beyond intrinsic resistance, the primary cause of ARB resistance is the horizontal gene transfer (HGT) of ARGs. These genes exploit mobile genetic elements (MGEs) to spread via conjugation, transformation, transduction, and outer membrane vesicles (OMVs). Currently, biological wastewater treatment is the primary pollution control method due to its cost-effectiveness. However, these biological processes can promote ARG propagation, significantly amplifying the environmental threat posed by antibiotics. This review also summarizes key mechanisms in the biological treatment of antibiotics and evaluates risks associated with major ARB/ARG removal processes. Our aim is to enhance understanding of ARB risks, their pathways and mechanisms in biotreatment, and potential biomedical applications for pollution control. Full article

Extracellular vesicles (EVs) hold great promise in the fields of diagnostics and therapeutics. However, the heterogeneity of these membrane-enclosed messengers and the complexity of the biological samples in which they occur pose significant research challenges. The aim of this study was to improve the reliability of size-exclusion chromatography (SEC) and immunolabelling as common approaches in the EV field, and to provide a comprehensive characterisation tool for diverse EV preparations. Profiling of SEC-separated sample components was conducted through light absorbance, fluorescence, and light scattering, providing insights into particle content, size, protein content, and specific markers. Key considerations for assay robustness, including SEC mobile phase composition and immunostaining parameters, were addressed. Respecting the importance of controlled immunolabelling and preanalytical factors, the method efficiently reveals changes in the sample profile with respect to particles and small impurities. The detailed analytical capabilities and method adaptability offer a practical way to enhance the efficiency of EV research and applications. Full article

Insulin-regulated glucose uptake is a central mechanism in maintaining systemic glucose homeostasis, primarily occurring in skeletal muscle and adipose tissue. This process relies on the insulin-stimulated translocation of the glucose transporter, GLUT4, from specialized intracellular compartments, known as GLUT4 storage vesicles (GSVs), to the plasma membrane. Disruption of this pathway is a hallmark of insulin resistance and a key contributor to the pathogenesis of type 2 diabetes. Recent advances have provided critical insights into both the insulin signalling cascades and the complex biogenesis, as well as the trafficking and fusion dynamics of GSVs. This review synthesizes the current understanding of the molecular mechanisms governing GSV mobilization and membrane fusion, highlighting key regulatory nodes that may become dysfunctional in metabolic disease. By elucidating these pathways, we propose new therapeutic avenues targeting GSV trafficking to improve insulin sensitivity and combat type 2 diabetes. Full article

Plantar fasciitis is a common condition characterized by inflammation and degeneration of the plantar fascia, leading to heel pain and reduced mobility. Affecting both athletic and non-athletic populations, it is a leading cause of foot-related medical visits. Conservative treatments, including rest, physical therapy, and corticosteroid injections, provide relief for most patients, but a subset experiences persistent symptoms requiring advanced therapies. Emerging biologic treatments, such as platelet-rich plasma (PRP) and mesenchymal stem/stromal cell (MSC) therapy, have demonstrated potential in promoting tissue regeneration and reducing inflammation. Recently, MSC-derived extracellular vesicles (MSC-EVs) have gained attention for their regenerative properties, offering a promising, cell-free therapeutic approach. EVs mediate tissue repair through immunomodulation, anti-inflammatory signaling, and extracellular matrix stabilization. Preclinical studies suggest that EV therapy may improve tendon and ligament healing by promoting M2 macrophage polarization, inhibiting excessive metalloproteinase activity, and enhancing vascular remodeling. This review explores the potential of MSC-EVs as an innovative, non-surgical treatment for plantar fasciitis, addressing their mechanisms of action and current evidence in musculoskeletal regeneration. Full article