Project description:Glioblastoma (GBM) is one of the most aggressive cancers of the central nervous system. Despite current advances in non-invasive imaging and the advent of novel therapeutic modalities, patient survival remains very low. There is a critical need for the development of effective biomarkers for GBM diagnosis and therapeutic monitoring. Extracellular vesicles (EVs) produced by GBM tumors have been shown to play an important role in cellular communication and modulation of the tumor microenvironment. As GBM-derived EVs contain specific "molecular signatures" of their parental cells and are able to transmigrate across the blood-brain barrier into biofluids such as the blood and cerebrospinal fluid (CSF), they are considered as a valuable source of potential diagnostic biomarkers. Given the relatively harsh extracellular environment of blood and CSF, EVs have to endure and adapt to different conditions. The ability of EVs to adjust and function depends on their lipid bilayer, metabolic content and enzymes and transport proteins. The knowledge of EVs metabolic characteristics and adaptability is essential for their utilization as diagnostic and therapeutic tools. The main aim of this study was to determine the metabolome of small EVs or exosomes derived from different GBM cells and compare to the metabolic profile of their parental cells using NMR spectroscopy. In addition, a possible flux of metabolic processes in GBM-derived EVs was simulated using constraint-based modeling from published proteomics information. Our results showed a clear difference between the metabolic profiles of GBM cells, EVs and media. Machine learning analysis of EV metabolomics, as well as flux simulation, supports the notion of active metabolism within EVs, including enzymatic reactions and the transfer of metabolites through the EV membrane. These results are discussed in the context of novel GBM diagnostics and therapeutic monitoring.
Project description:Extracellular vesicles (EVs), specifically exosomes, carry a cell-type dependent cargo that is transported to the recipient cell and translated in the presence of a required machinery. Differences in the cargo carried by the corneal and conjunctival-derived EVs could be the agent that triggers the transdifferentiation of these two cell populations. Therefore, this study investigates the role of EVs in triggering the plasticity of corneal and conjunctival epithelial cells and identifies prospective miRNA and genes responsible for maintaining ocular surface homeostasis. The EVs were extracted from the conditioned media (after starving) of corneal epithelial (hTCEpi) and conjunctival (HCjE-Gi) cell lines using ultracentrifugation. HCjE-Gi cells were cultured with hTCEpi-derived EVs and vice-versa. The EVs were characterized as exosomes using Nanosight and Flow cytometry. KRT3 and KRT12 were used as associated corneal markers, whereas KRT7 and KRT13 were used as associated conjunctival markers with ΔNp63 as a differentiation marker. Shift of these markers was an indication of transdifferentiation. The cargo of the extracted exosomes from both the cell types was explored using next-generation sequencing. The hTCEpi-derived EVs induced conjunctival epithelial cells to express the corneal-associated markers KRT3 and KRT12, losing their conjunctival phenotype at both the mRNA and protein level. Simultaneously, HCjE-Gi-derived EVs induced corneal epithelial cells to express the conjunctival associated markers KRT7 and KRT13, losing their corneal phenotype. This process of differentiation was accompanied by an intermediate step of cell de-differentiation showed by up-regulation in the expression of epithelial stem cell marker ΔNp63, also shown on the ex vivo human cadaveric donor corneas. miRNA molecules (total of 11 including precursor and mature) with significant differences in their relative abundance between the two populations (p < 0.05) were found and investigated. miR-9-5p expression was higher in HCjE-Gi cells and HCjE-Gi-derived EVs when compared to hTCEpi cells and hTCEPi-derived EVs (p < 0.001). The results suggest that EVs released by the two cell types have the ability to influence the transdifferentiation of human conjunctival and corneal epithelial cells. miR-9-5p could have a role in stem cell homeostasis and cell differentiation via HES-1 gene.
Project description:Microglia act as the immune cells of the central nervous system (CNS). They play an important role in maintaining brain homeostasis but also in mediating neuroimmune responses to insult. The interactions between neurons and microglia represent a key process for neuroimmune regulation and subsequent effects on CNS integrity. However, the molecular mechanisms of neuron-glia communication in regulating microglia function are not fully understood. One recently described means of this intercellular communication is via nano-sized extracellular vesicles (EVs) that transfer a large diversity of molecules between neurons and microglia, such as proteins, lipids, and nucleic acids. To determine the effects of neuron-derived EVs (NDEVs) on microglia, NDEVs were isolated from the culture supernatant of rat cortical neurons. When NDEVs were added to primary cultured rat microglia, we found significantly improved microglia viability via inhibition of apoptosis. Additionally, application of NDEVs to cultured microglia also inhibited the expression of activation surface markers on microglia. Furthermore, NDEVs reduced the LPS-induced proinflammatory response in microglia according to reduced gene expression of proinflammatory cytokines (TNF-α, IL-6, MCP-1) and iNOS, but increased expression of the anti-inflammatory cytokine, IL-10. These findings support that neurons critically regulate microglia activity and control inflammation via EV-mediated neuron-glia communication. (Supported by R21AA025563 and R01AA025591).
Project description:Liver cancer (LC) is one of the most common cancers and represents the third highest cause of cancer-related deaths worldwide. Extracellular vesicle (EVs) cargoes, which are selectively enriched in RNA, offer great promise for the diagnosis, prognosis and treatment of LC. Our study analyzed the RNA cargoes of EVs derived from 4 liver-cancer cell lines: HuH7, Hep3B, HepG2 (hepato-cellular carcinoma) and HuH6 (hepatoblastoma), generating two different sets of sequencing libraries for each. One library was size-selected for small RNAs and the other targeted the whole transcriptome. Here are reported genome wide data of the expression level of coding and non-coding transcripts, microRNAs, isomiRs and snoRNAs providing the first comprehensive overview of the extracellular-vesicle RNA cargo released from LC cell lines. The EV-RNA expression profiles of the four liver cancer cell lines share a similar background, but cell-specific features clearly emerge showing the marked heterogeneity of the EV-cargo among the individual cell lines, evident both for the coding and non-coding RNA species.
Project description:Microglia are the chief immune cells of the brain and have been reported to be activated in severe malaria. Their activation may drive towards neuroinflammation in cerebral malaria. Malaria-infected red blood cell derived-extracellular vesicles (MiREVs) are produced during the blood stage of malaria infection. They mediate intercellular communication and immune regulation, among other functions. During cerebral malaria, the breakdown of the blood-brain barrier can promote the migration of substances such as MiREVs from the periphery into the brain, targeting cells such as microglia. Microglia and extracellular vesicle interactions in different pathological conditions have been reported to induce neuroinflammation. Unlike in astrocytes, microglia-extracellular vesicle interaction has not yet been described in malaria infection. Therefore, in this study, we aimed to investigate the uptake of MiREVs by human microglia cells and their cytokine response. Human blood monocyte-derived microglia (MoMi) were generated from buffy coats of anonymous healthy donors using Ficoll-Paque density gradient centrifugation. The MiREVs were isolated from the Plasmodium falciparum cultures. They were purified by ultracentrifugation and labeled with PKH67 green fluorescent dye. The internalization of MiREVs by MoMi was observed after 4 h of co-incubation on coverslips placed in a 24-well plate at 37 °C using confocal microscopy. Cytokine-gene expression was investigated using rt-qPCR, following the stimulation of the MoMi cells with supernatants from the parasite cultures at 2, 4, and 24 h, respectively. MiREVs were internalized by the microglia and accumulated in the perinuclear region. MiREVs-treated cells increased gene expression of the inflammatory cytokine TNFα and reduced gene expression of the immune suppressive IL-10. Overall, the results indicate that MiREVs may act on microglia, which would contribute to enhanced inflammation in cerebral malaria.
Project description:Neurodegenerative diseases (NDs), such as Alzheimer's disease (AD), are driven by neuroinflammation triggered by activated microglial cells; hence, the phenotypic regulation of these cells is an appealing target for intervention. Human adipose tissue-derived mesenchymal stem cells (hAD-MSCs) may be a potential therapeutic candidate to treat NDs given their immunomodulatory properties. Evidence suggests that the mechanism of action of hAD-MSCs is through their secretome, which includes secreted factors such as cytokines, chemokines, or growth factors as well as extracellular vesicles (EVs). Recently, EVs have emerged as important mediators in cell communication given, they can transfer proteins, lipids, and RNA species (i.e., miRNA, mRNA, and tRNAs) to modulate recipient cells. However, the therapeutic potential of hAD-MSCs and their secreted EVs has not been fully elucidated with respect to human microglia. In this study, we determined the therapeutic potential of different hAD-MSCs doses (200,000, 100,000, and 50,000 cells) or their secreted EVs (50, 20, or 10 µg/ml), on human microglial cells (HMC3) that were activated by lipopolysaccharides (LPS). Upregulation of inducible nitric oxide synthase (iNOS), an activation marker of HMC3 cells, was prevented when they were cocultured with hAD-MSCs and EVs. Moreover, hAD-MSCs inhibited the secretion of proinflammatory factors, such as IL-6, IL-8, and MCP-1, while their secreted EVs promoted the expression of anti-inflammatory mediators such as IL-10 or TIMP-1 in activated microglia. The present data therefore support a role for hAD-MSCs and their secreted EVs, as potential therapeutic candidates for the treatment of NDs.
Project description:BackgroundExtracellular vesicles (EVs) are produced and secreted from most cells of the body and can be recovered in biological fluids. Although there has been extensive characterisation of the protein and nucleic acid component of EVs, their lipidome has received little attention and may represent a unique and untapped source of biomarkers for prostate cancer diagnosis and prognosis.MethodsEVs were isolated from non-tumourigenic (RWPE1), tumourigenic (NB26) and metastatic (PC-3) prostate cell lines. Lipids were extracted and subsequently used for targeted lipidomics analysis for the quantitation of molecular lipid species.ResultsA total of 187 molecular lipid species were quantitatively identified in EV samples showing differential abundance between RWPE1, NB26 and PC-3 EV samples. Fatty acids, glycerolipids and prenol lipids were more highly abundant in EVs from non-tumourigenic cells, whereas sterol lipids, sphingolipids and glycerophospholipids were more highly abundant in EVs from tumourigenic or metastatic cells.ConclusionsThis study identified differences in the molecular lipid species of prostate cell-derived EVs, increasing our understanding of the changes that occur to the EV lipidome during prostate cancer progression. These differences highlight the importance of characterising the EV lipidome, which may lead to improved diagnostic and prognostic biomarkers for prostate cancer.
Project description:Breast cancer is a heterogeneous disease, and different subtypes of breast cancer show distinct cellular morphology, gene expression, metabolism, motility, proliferation, and metastatic potential. Understanding the molecular features responsible for this heterogeneity is important for correct diagnosis and better treatment strategies. Extracellular vesicles (EVs) and their associated molecules have gained much attention as players in intercellular communication, ability to precondition specific organs for metastatic invasion, and for their potential role as circulating cancer biomarkers. EVs are released from the cells and contain proteins, DNA, and long and small RNA species. Here we show by high-throughput small RNA-sequencing that EVs from nine different breast cancer cell lines share common characteristics in terms of small RNA content that are distinct from their originating cells. Most strikingly, a highly abundant small RNA molecule derived from the nuclear 28S rRNA is vastly enriched in EVs. The miRNA profiles in EVs correlate with the cellular miRNA expression pattern, but with a few exceptions that includes miR-21. This cancer-associated miRNA is retained in breast cancer cell lines. Finally, we report that EVs from breast cancer cell lines cluster together based on their small RNA signature when compared to EVs derived from other cancer cell lines. Altogether, our data demonstrate that breast cancer cell lines manifest a specific small RNA signature in their released EVs. This opens up for further evaluation of EVs as breast cancer biomarkers.
Project description:Evolution of melanoma from a primary tumor to widespread metastasis is crucially dependent on lymphatic spread. The mechanisms regulating the initial step in metastatic dissemination via regional lymph nodes remain largely unknown; however, evidence supporting the establishment of a pre-metastatic niche is evolving. We have previously described a dysfunctional immune profile including reduced expression of dendritic cell (DC) maturation markers in the first node draining from the primary tumor, the sentinel lymph node (SLN). Importantly, this phenotype is present prior to evidence of nodal metastasis. Herein, we evaluate melanoma-derived extracellular vesicles (EVs) as potential mediators of the premetastatic niche through cargo-specific polarization of DCs. DCs matured in vitro in the presence of melanoma EVs demonstrated significantly impaired expression of CD83 and CD86 as well as decreased expression of Th1 polarizing chemokines Flt3L and IL15 and migration chemokines MIP-1α and MIP-1β compared to liposome-treated DCs. Profiling of melanoma EV cargo identified shared proteomic and RNA signatures including S100A8 and S100A9 protein cargo, which in vitro compromised DC maturation similar to melanoma EVs. Early evidence demonstrates that similar EVs can be isolated from human afferent lymphatic fluid ex vivo. Taken together, here, we propose melanoma EV cargo as a mechanism by which DC maturation is compromised warranting further study to consider this as a potential mechanism enabled by the primary tumor to establish the premetastatic niche in tumor-draining SLNs of patients.
Project description:The functional preservation of the central nervous system (CNS) is based on the neuronal plasticity and survival. In this context, the neuroinflammatory state plays a key role and involves the microglial cells, the CNS-resident macrophages. In order to better understand the microglial contribution to the neuroprotection, microglia-derived extracellular vesicles (EVs) were isolated and molecularly characterized to be then studied in neurite outgrowth assays. The EVs, mainly composed of exosomes and microparticles, are an important cell-to-cell communication process as they exhibit different types of mediators (proteins, lipids, nucleic acids) to recipient cells. The medicinal leech CNS was initially used as an interesting model of microglia/neuron crosstalk due to their easy collection for primary cultures. After the microglia-derived EV isolation following successive methods, we developed their large-scale and non-targeted proteomic analysis to (i) detect as many EV protein markers as possible, (ii) better understand the biologically active proteins in EVs and (iii) evaluate the resulting protein signatures in EV-activated neurons. The EV functional properties were also evaluated in neurite outgrowth assays on rat primary neurons and the RNAseq analysis of the microglia-derived EVs was performed to propose the most representative miRNAs in microglia-derived EVs. This strategy allowed validating the EV isolation, identify major biological pathways in EVs and corroborate the regenerative process in EV-activated neurons. In parallel, six different miRNAs were originally identified in microglia-derived EVs including 3 which were only known in plants until now. The analysis of the neuronal proteins under the microglial EV activation suggested possible miRNA-dependent regulation mechanisms. Taken together, this combination of methodologies showed the leech microglial EVs as neuroprotective cargos across species and contributed to propose original EV-associated miRNAs whose functions will have to be evaluated in the EV-dependent dialog between microglia and neurons.