Aim: This study investigates the change in profiles of miRNAs in extracellular vesicles released during Toxoplasma gondii (T. gondii) infection. T. gondii has been implicated in host behavioural modifications and neuroinflammatory responses, yet the molecular mechanisms involved in these changes remain poorly understood. Extracellular vesicles, involved in intercellular communication, play an important role in host-pathogen interactions, particularly through the transfer of microRNAs (miRNAs); however, the impact of extracellular vesicle miRNAs in T. gondii infection remains largely unexplored.

Methods: Human BE(2)-M17 neuronal cells were infected with Toxoplasma gondii to investigate infection-induced changes in extracellular vesicle (EV) miRNA content. EVs from infected and control cultures were isolated, characterised, and subjected to miRNA extraction followed by next-generation sequencing and differential expression analysis using standard bioinformatic pipelines. Predicted miRNA targets were integrated across multiple databases and analysed for enriched pathways to identify neuronal regulatory networks.

Results: Pathway network analysis identified key neurobiological pathways, including neuroplasticity, neurotransmission, and neuroinflammation in high-confidence miRNA targets with gene enrichment of neurotrophin and long-term depression and long-term potentiation, which may underlie parasite-induced alterations in neural function. Bioinformatic analysis of extracellular vesicle miRNA profiles from infected and uninfected neuronal cells revealed a set of miRNAs including hsa-miR-4645-3p with significant upregulation in response to infection.

Conclusion: These findings suggest that T. gondii modulates host neuronal processes through extracellular vesicle-mediated miRNA transfer, providing a potential mechanistic link between infection and parasite-associated cognitive and neuropsychiatric disturbances.

A recent study on Cell Reports Medicine by Wang et al. introduces a hybrid exosome platform - selenized neural stem cell-derived exosomes (SeNExo) - that couples the biological functionality of neural stem cell exosomes with the antioxidant power of ultrasmall nanoselenium. SeNExo crosses the blood-brain barrier via apolipoprotein E (APOE)-lipoprotein receptor-associated protein-1 (LRP1) interaction, scavenges reactive oxygen species, and restores glial-neuron homeostasis. It demonstrates potent therapeutic efficacy in both traumatic brain injury and spinal cord injury mouse models. This work highlights a promising direction for engineering multifunctional, cell-free nanotherapeutics for central nervous system repair.

Mesenchymal stromal/stem cell-derived extracellular vesicles (MSC-EVs) have emerged as promising acellular therapeutics in regenerative medicine, offering a safer and more controllable alternative to whole-cell therapies. Their therapeutic efficacy, however, is highly dependent on their molecular cargo, which reflects the physiological state and environmental conditions of the parent MSCs. Priming of mesenchymal stromal/stem cells (MSCs) with defined stimuli such as hypoxia, inflammatory cytokines, 3D culture systems, biomaterials, or pharmacological agents has been increasingly employed to enhance extracellular vesicle (EV) bioactivity. These strategies modulate EV content, enriching vesicles with regenerative, immunomodulatory, angiogenic, and antioxidant factors. For instance, hypoxic priming activates hypoxia-inducible factor-1α-driven gene expression, promoting the packaging of angiogenic and anti-inflammatory molecules, while cytokine-based priming upregulates immunosuppressive proteins and regulatory microRNAs. Similarly, 3D culture mimics aspects of the native tissue microenvironment, augmenting the secretion of EVs with enhanced reparative potential. Emerging combination-based approaches synergize these effects, generating EVs with superior therapeutic profiles. Despite encouraging preclinical data, translation to clinical application is challenged by variability in MSC sources, priming conditions, and EV isolation methods. Standardization of protocols, validated potency assays, and regulatory harmonization are critical for clinical advancement. This mini-review summarizes current priming strategies, the underlying mechanisms influencing EV cargo, and their functional implications in disease models, while highlighting key barriers and future directions for the clinical translation of primed MSC-EV therapies.

Aim: To investigate the therapeutic potential and underlying mechanism of mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in treating hepatorenal syndrome (HRS), a condition lacking therapies for multi-organ damage.

Methods: EVs were isolated from human umbilical cord MSCs and characterized by transmission electron microscopy, nanoparticle tracking analysis, and proteomics. A murine model of HRS, induced by bile duct ligation (BDL), was established, and mice received intravenous MSC-EVs treatment. Therapeutic efficacy was assessed through histopathology, serum biochemistry, and analysis of necroptosis, inflammation, and fibrosis markers.

Results: Proteomic profiling of MSC-EVs revealed significant enrichment of proteins involved in renal processes, anti-fibrosis, and immune regulation. In BDL-induced HRS mice, MSC-EVs treatment demonstrated potent multi-organ protective effects. This was evidenced by alleviation of hepatic necroptosis and renal tubular injury, downregulation of interleukin-17 expression, and concurrent attenuation of fibrosis in both liver and kidney tissues. Consequently, significant improvements in hepatic and renal function markers were observed.

Conclusion: MSC-EVs represent a novel and effective cell-free nanotherapeutic strategy for HRS. They confer protection through multi-faceted mechanisms, including inhibition of necroptosis, immune reprogramming, and fibrosis resolution, offering a promising paradigm for the treatment of multi-organ failure.

The existence of small vesicles released by cells into the extracellular space was first documented over 40 years ago. These nanoparticles, now recognized as extracellular vesicles (EVs), were originally defined as “cellular dust” reflecting the early belief that their primary function was to dispose of cellular waste. Nowadays, it is widely acknowledged that EVs make a fundamental contribution to intercellular communication, being capable of transporting biologically active molecules, including proteins and nucleic acids, which regulate both physiological and pathological processes. Their involvement in various diseases, particularly cancer, has been well documented. EVs influence tumor development, progression, and therapeutic response, and have therefore been considered potential diagnostic and prognostic biomarkers. In this review, we focus on the contribution of EVs in modulating tumor cell metabolism and the tumor microenvironment. Specifically, we describe how EVs promote angiogenesis, induce the transformation of fibroblasts into cancer-associated fibroblasts, and influence extracellular matrix remodeling. Additionally, we explore their contribution to the reprogramming of tumor metabolism, including glycolytic, lipid, and amino acid pathways. We provide an in-depth overview of the key molecules carried by EVs that contribute to these pro-tumorigenic effects and of the underlying mechanisms involved.

Aim: This proof-of-concept study aimed to evaluate the impact of fluorescence-based sorting on the microRNA (miRNA) molecular profile of extracellular vesicles (EVs) derived from adipose-derived mesenchymal stromal cells (ASCs) (ASC-EVs), with a focus on osteoarthritis (OA) as a model disease.

Methods: ASCs from five human donors were characterized by flow cytometry and cultured to collect conditioned media. EV isolation was performed by fluorescence-based sorting using a high-sensitivity cell sorter calibrated for particles ≥ 100 nm. In both ASC-EVs and sorted ASC-EVs (sASC-EVs), EV and MSC markers were analysed by flow cytometry, while size and morphology were assessed via nanoparticle tracking analysis and electron microscopy. Small RNA sequencing was used to profile miRNAs, followed by differential expression and functional enrichment analyses.

Results: EVs displayed comparable size distributions and surface marker profiles before and after sorting. In contrast, small RNA sequencing revealed a marked reduction in the number of detectable miRNAs in sASC-EVs relative to EVs isolated by standard ultracentrifugation (285 vs. 749). Among these, 271 miRNAs were shared between groups, exhibiting a strong correlation in relative abundance and functional enrichment in angiogenesis, inflammation modulation and gene silencing pathways. Nevertheless, differential expression analysis identified 32 upregulated and 6 downregulated miRNAs in sASC-EVs, with 14 miRNAs detected exclusively after sorting. Despite these transcriptional differences, the overall balance between protective and detrimental OA-related miRNAs remained positive and was preserved across both ASC-EVs and sASC-EVs.

Conclusion: While sorting reduces EV-associated miRNA diversity, it retains core functional signals. The difference in recovered miRNAs may be due to lower EV recovery, exclusion of miRNA-bound non-vesicular particles or loss of small EVs undetectable by fluorescence-based sorting techniques. Overall, these preliminary findings highlight a trade-off between purity and complexity, underscoring the importance of optimizing EV isolation protocols for clinical applications.