HansaBioMed (Estonia)

ABSTRACTFollicular fluid extracellular vesicles (FF EVs) facilitate communication between oocytes and somatic cells within the ovarian follicle, playing a pivotal role in follicular development. This study highlights the molecular and functional distinctions between small (SEV) and large (LEV) FF EV subpopulations, revealing their specialised regulatory roles in granulosa cell (GC) biology and their consequential impact on ovarian function. Single‐EV profiling uncovered distinct tetraspanin distributions, with LEVs containing a lower proportion of CD9/CD63/CD81‐positive particles compared to SEVs. Fluorescent labelling confirmed uptake of both SEVs and LEVs by GCs, supporting their capacity to impact cellular behaviour. Functionally, LEVs increased testosterone production by GCs, whilst SEVs had no effect on steroid hormone secretion, suggesting a specific role for LEVs in androgen biosynthesis. Transcriptomic analysis revealed extensive SEV‐induced changes in GC gene expression, affecting pathways involved in transcription, TGF‐β signalling, extracellular matrix (ECM) remodelling and cell cycle regulation. In contrast, LEVs elicited minimal transcriptional changes, primarily modulating genes associated with immune regulation and oxidative stress defence. Small RNA sequencing further revealed distinct non‐coding RNA (ncRNA) profiles, with SEVs enriched in miRNAs targeting pathways critical for GC differentiation, whilst LEVs carried higher levels of piRNAs implicated in maintaining genomic stability. These findings advance our understanding of FF EV‐mediated intercellular communication and underscore the importance of investigating EV subpopulations independently.

ABSTRACT Follicular fluid extracellular vesicles (FF EVs) facilitate communication between oocytes and somatic cells within the ovarian follicle, playing a pivotal role in follicular development. This study highlights the molecular and functional distinctions between small (SEV) and large (LEV) FF EV subpopulations, revealing their specialized regulatory roles in granulosa cell (GC) biology and their consequential impact on ovarian function. Single-EV profiling uncovered distinct tetraspanin distributions, with LEVs containing a lower proportion of CD9/CD63/CD81-positive particles compared to SEVs. Functionally, SEVs reduced estradiol secretion by GCs, whereas LEVs enhanced progesterone production, demonstrating their differential effects on steroidogenesis. Transcriptomic analysis revealed extensive SEV-induced changes in GC gene expression, affecting pathways involved in transcription, TGF-β signaling, extracellular matrix (ECM) remodeling, and cell cycle regulation. In contrast, LEVs elicited minimal transcriptional changes, primarily modulating genes associated with immune regulation and oxidative stress defense. Small RNA sequencing further revealed distinct non-coding RNA (ncRNA) profiles, with SEVs enriched in miRNAs targeting pathways critical for GC differentiation, while LEVs carried higher levels of piRNAs implicated in maintaining genomic stability. These findings advance our understanding of FF EV-mediated intercellular communication and underscore the importance of investigating EV subpopulations independently.

Abstract Extracellular vesicles (EVs) have mostly been investigated as carriers of biological therapeutics such as proteins and RNA. Nevertheless, small-molecule drugs of natural or synthetic origin have also been loaded into EVs, resulting in an improvement of their therapeutic properties. A few methods have been employed for EV cargo loading, but poor yield and drastic modifications of vesicles remain unsolved challenges. We tested a different strategy based on temporary pH alteration through incubation of EVs with alkaline sodium carbonate, which resulted in conspicuous exogenous molecule incorporation. In-depth characterization showed that vesicle size, morphology, composition, and uptake were not affected. Our method was more efficient than gold-standard electroporation, particularly for a potential therapeutic toxin: the plant Ribosome Inactivating Protein saporin. The encapsulated saporin resulted protected from degradation, and was efficiently conveyed to receiving cancer cells and triggered cell death. EV-delivered saporin was more cytotoxic compared to the free toxin. This approach allows both the structural preservation of vesicle properties and the transfer of protected cargo in the context of drug delivery.

BackgroundThe identification of novel biomarkers for the early detection and monitoring of gastric (GC) and colorectal cancer (CRC) is of paramount importance. TM9SF4 is a newly described V-ATPase interacting protein involved in the malignant progression of cancer cells. While TM9SF4 expression pattern and cellular localization have been described in in vitro in tumor cell lines of different histotypes, its expression in gastrointestinal tumor tissues has never been investigated.MethodsIn this study, we detected by immunohistochemistry (IHC) in tumor and surrounding healthy tissues TM9SF4, in comparison with clinically adopted biomarkers CEA and CA 19-9 to evaluate TM9SF4 potential as a novel tissue marker for early detection and monitoring of GC and CRC cancers.ResultsThe expression of TM9SF4, CEA and CA 19-9 was evaluated in samples from 108 cancer patients (68 with GC and 40 CRC) and in healthy tissues from 20 non-cancer patients. Our results clearly suggest that TM9SF4 expression was significantly increased in GC and CRC samples and significantly correlated to disease stage in both cancer types.ConclusionsWe propose TM9SF4 as highly specific cancer biomarker, exploitable for disease detection and staging of gastrointestinal cancers patients, with tumor tissue levels of expression outperforming those of clinically adopted markers such as CEA and CA 19-9.

The mechanical properties of extracellular vesicles (EVs) are known to influence their biological function, in terms of, e.g., cellular adhesion, endo/exocytosis, cellular uptake, and mechanosensing. EVs have a characteristic nanomechanical response which can be probed via force spectroscopy (FS) and exploited to single them out from nonvesicular contaminants or to discriminate between subtypes. However, measuring the nanomechanical characteristics of individual EVs via FS is a labor-intensive and time-consuming task, usually limiting this approach to specialists. Herein, we describe a simple atomic force microscopy based experimental procedure for the simultaneous nanomechanical and morphological analysis of several hundred individual nanosized EVs within the hour time scale, using basic AFM equipment and skills and only needing freely available software for data analysis. This procedure yields a "nanomechanical snapshot" of an EV sample which can be used to discriminate between subpopulations of vesicular and nonvesicular objects in the same sample and between populations of vesicles with similar sizes but different mechanical characteristics. We demonstrate the applicability of the proposed approach to EVs obtained from three very different sources (human colorectal carcinoma cell culture, raw bovine milk, and Ascaris suum nematode excretions), recovering size and stiffness distributions of individual vesicles in a sample. EV stiffness values measured with our high-throughput method are in very good quantitative accord with values obtained by FS techniques which measure EVs one at a time. We show how our procedure can detect EV samples contamination by nonvesicular aggregates and how it can quickly attest the presence of EVs even in samples for which no established assays and/or commercial kits are available (e.g., Ascaris EVs), thus making it a valuable tool for the rapid assessment of EV samples during the development of isolation/enrichment protocols by EV researchers. As a side observation, we show that all measured EVs have a strikingly similar stiffness, further reinforcing the hypothesis that their mechanical characteristics could have a functional role.