Cancers doi: 10.20517/evcna.2025.139

Authors: Marta Pagnini,Maria Conti,Giorgia Puddu,Matteo Daverio,Alessandro Celi,Erica Bazzan,Tommaso Neri

Microbial extracellular vesicles (mEVs) are emerging as key mediators at the host-microbe interface in the lung, playing a remarkable dual role as both pathogenic drivers and therapeutic modulators. These nano-sized, membrane-bound structures (20-400 nm) secreted by bacteria, fungi, and other microorganisms carry diverse bioactive cargo including lipids, proteins, and nucleic acids that can profoundly influence host immune responses and tissue homeostasis. mEVs derived from probiotic bacteria demonstrate significant therapeutic potential as immunomodulatory agents capable of reducing pulmonary inflammation and enhancing epithelial barrier function. These probiotic-derived vesicles represent a novel class of postbiotics - bioactive microbial products that confer health benefits without requiring live microbial cells. Conversely, in pathogenic contexts, mEVs from bacteria such as Pseudomonas aeruginosa and Escherichia coli trigger robust inflammatory responses in the lung through pattern recognition receptor activation, particularly Toll-like receptors (TLRs)-2 and TLR-4, leading to upregulation of pro-inflammatory cytokines and contributing to chronic respiratory conditions including asthma and chronic obstructive pulmonary disease. Given its extensive surface area and highly specialized immune network, the lung represents a highly receptive site for mEV-mediated interactions. This review synthesizes evidence on pathogenic mechanisms of mEVs and explores their therapeutic potential in respiratory medicine, with specific focus on: (1) the role of environmentally-derived mEVs from dust and airborne sources in chronic respiratory inflammation; (2) recent experimental evidence of probiotic-derived mEVs therapeutic effects across diverse pulmonary conditions and (3) the concept of mEVs as both protective postbiotics and inflammatory triggers in the lung.

Cancers doi: 10.20517/evcna.2025.122

Authors: Jiao Luo,You Cai,Yanling Cai,Chunxia Zhang,Ankang Liu,Yongyang Huo,Xuehui Fan,Ruixue Ye,Hong Gao,Meiling Huang,Xiaohua Zhang,Mingchao Zhou,Yulong Wang

Aim: Extracellular vesicles (EVs) contribute to stroke rehabilitation by mediating intercellular signaling during inflammation and tissue repair. Here we report EV-associated surface proteins as potential biomarkers for predicting recovery of activities of daily living (ADL) during the subacute phase of ischemic stroke (IS).

Methods: IS patients and healthy controls (HCs) were recruited for this study, with serum samples analyzed across three study stages. In the discovery subset (10 IS, 6 HCs), serum proteomics was used to identify differentially expressed proteins (DEPros) and perform Gene Ontology (GO) enrichment analysis. In the exploration subset (7 IS, 12 HCs), a proximity-dependent barcoding assay (PBA) was employed to profile surface proteins on individual EVs and screen for biomarker candidates. In a validation cohort, patients were grouped by ADL improvement (little-effect recovery, LE, n = 30; obvious-effect recovery group, OE, n = 22) based on Longshi Scale and Barthel Index assessments at admission and at 3 months follow-up. Targeted biomarker validation was performed with enzyme-linked immunosorbent assay (ELISA) and receiver operating characteristic (ROC) analysis.

Results: A total of 113 DEPros were identified, with GO term enrichment in EV-related pathways. PBA profiling revealed matrix metalloproteinase 9 (MMP9), carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), melanoma cell adhesion molecule (MCAM), and gelsolin (GSN) as candidate biomarkers. In the validation cohort, MMP9 and CEACAM1 were significantly elevated in the LE group. ROC analysis showed area under the curve (AUC) of 0.726 for MMP9 and 0.700 for CEACAM1 in distinguishing LE from OE.

Conclusion: Elevated serum levels of EV-associated biomarkers MMP9 and CEACAM1 were associated with poor ADL recovery, supporting their potential as prognostic biomarkers for stroke rehabilitation outcomes.

Cancers doi: 10.20517/evcna.2025.170

Authors: Yilin Huang,Yan Zeng,Ailin Wu,Yang Chen,Yuanhao Zhou,Youni Zhang,Hai Zou,Weijiao Fan,Xiaoyi Chen,Jinyang Chen,Jie Wang,Xianghong Yang,Xiaoru Chang,Xiaozhou Mou,Yuexing Tu

Aim: Acute lung injury (ALI), marked by vigorous inflammatory reactions and elevated incidence, is a grave clinical issue for which efficacious pharmaceutical interventions are still lacking. This research delves into the anti-inflammatory actions and the associated pathways of nanovesicles originating from human umbilical cord mesenchymal stem cells (UCMSC-NVs) within a model of ALI induced by lipopolysaccharide (LPS).

Methods: UCMSC-NVs were prepared via serial extrusion and characterized using transmission electron microscopy and dynamic light scattering. Their effects on pulmonary inflammation and injury were evaluated in an LPS-induced ALI mouse model. Anti-inflammatory effects were analyzed using Western blot, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence, focusing on the role of hsa-let-7g-5p in regulating the nuclear factor κB (NF-κB)/NOD-like receptor protein 3 (NLRP3) pathway.

Results: The UCMSC-NVs acquired through serial extrusion displayed bilayer vesicle structures, with a mean diameter of around 100 nm. Moreover, these vesicles exhibited elevated expression levels of CD9, CD63, and CD81. Administration of UCMSC-NVs significantly alleviated lung damage, accompanied by a reduction in alveolar leakage and neutrophil infiltration. Furthermore, it significantly downregulated the expression of pro-inflammatory cytokines, such as interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α). UCMSC-NVs reduced macrophage infiltration in the lungs of ALI mice by inhibiting the NF-κB/NLRP3 signaling, leading to a shift in macrophage polarization, with decreased M1 and increased M2 polarization. Our findings demonstrated a novel therapeutic mechanism wherein hsa-let-7g-5p encapsulated within UCMSC-NVs alleviates inflammation by inhibiting NF-κB/NLRP3 expression, thereby mitigating ALI.

Conclusion: These results provide a foundation for the development of novel cell-free therapies with clinical potential for treating inflammatory lung diseases such as ALI and acute respiratory distress syndrome (ARDS).