Project description:Objective: To study the uptake by human embryos of extracellular vesicles secreted by the maternal endometrium, and to investigate their miRNA cargo, in order to describe their role in implantation and early embryo development. Design: Prospective descriptive study. Subjects: Healthy women oocyte donors with confirmed fertility and day 5 human blastocysts. Intervention: Endometrial biopsies were collected from healthy oocyte donors undergoing transvaginal ultrasound-guided cyst aspiration for oocyte retrieval. Main Outcome Measures: Extracellular vesicle were isolated from culture media of primary human endometrial epithelial cells by ultracentrifugation. Concentration and size were analyzed by nanoparticle tracking analysis, their morphology visualized by transmission electron microscopy and extracellular vesicle protein markers expression was determined by western blotting. Vesicles were fluorescently labelled with Bodipy-TR ceramide, and their uptake by human blastocysts was analyzed using confocal microscopy. Analysis of the miRNA cargo of extracellular vesicles was performed using miRNAseq, target genes of the most expressed miRNAs were annotated and functional enrichment analysis was performed. Results: Extracellular vesicle characterization revealed a size within 100-300 nm, and expression of extracellular vesicle protein markers HSP70, TSG101, CD9 and CD81. Fluorescent microscopy showed an efficient extracellular vesicle internalization by human blastocysts within 1-2h, being the fluorescent signal stronger in the hatched area of the embryo. miRNAseq described 149 annotated miRNAs and top 37 most expressed miRNAs targeted 6,592 genes. Functional enrichment analysis of these targeted genes indicated that they participate in several processes related to embryo development, oxygen metabolism, cell cycle, cell differentiation, apoptosis, metabolism, cellular organization or gene expression. Among miRNAs contained in these EVs, hsa-miR-92a-3p, hsa-let-7b-5p, hsa-miR-30a-5p, hsa-miR-24-3p, hsa-miR-21-5p and hsa-let-7a-5p were highly implicated in all these biological processes. Conclusion: Data suggest that extracellular vesicles secreted by human endometrial epithelial cells are internalized by human blastocysts, and transport miRNAs to modulate biological processes related to implantation events and early embryo development. Knowledge of the communication system between human endometrium and embryo via miRNA cargo of these vesicles could describe new biomarkers of implantation success and embryo competence.
Project description:Amyotrophic lateral sclerosis (ALS) is a terminal neurodegenerative disease. Clinical and molecular observations suggest that ALS pathology originates at a single site and spreads in an organized and prion-like manner, possibly driven by extracellular vesicles. Extracellular vesicles transfer cargo molecules associated with ALS pathogenesis, such as misfolded and aggregated proteins and dysregulated microRNAs (miRNAs). However, it is poorly understood whether altered levels of circulating extracellular vesicles or their cargo components reflect pathological signatures of the disease. In this study, we used immuno-affinity-based microfluidic technology, electron microscopy, and NanoString miRNA profiling to isolate and characterize extracellular vesicles and their miRNA cargo from frontal cortex, spinal cord, and serum of sporadic ALS (n=15) and healthy control (n=16) participants. We found larger extracellular vesicles in ALS spinal cord versus controls and smaller sized vesicles in ALS serum. However, there were no changes in the number of extracellular vesicles between cases and controls across any tissues. Characterization of extracellular vesicle-derived miRNA cargo in ALS compared to controls identified significantly altered miRNA levels in all tissues; miRNAs were reduced in ALS frontal cortex and spinal cord and increased in serum. Two miRNAs were dysregulated in all three tissues: miR-342-3p was increased in ALS, and miR-1254 was reduced in ALS. Additional miRNAs overlapping across two tissues included miR-587, miR-298, miR-4443, and miR-450a-2-3p. Predicted targets and pathways associated with the dysregulated miRNAs across the ALS tissues were associated with common biological pathways altered in neurodegeneration, including axon guidance and long-term potentiation. A predicted target of one identified miRNA (N-deacetylase and N-sulfotransferase 4; NDST4) was likewise dysregulated in an in vitro model of ALS, verifying potential biological relevance. Together, these findings demonstrate that circulating extracellular vesicle miRNA cargo mirror those of the central nervous system disease state in ALS, and thereby offer insight into possible pathogenic factors and diagnostic opportunities.