Project description:Cellular senescence prevents the proliferation of cells at risk for neoplastic transformation. However, the altered secretome of senescent cells can promote the growth of the surrounding cancer cells. Although extracellular vesicles (EVs) have emerged as new players in intercellular communication, their role in the function of senescent cell secretome has been largely unexplored. Here, we show that exosome-like small EVs (sEVs) are important mediators of the pro-tumorigenic function of senescent cells. sEV-associated EphA2 secreted from senescent cells binds to ephrin-A1 that is highly expressed in several types of cancer cells and promotes cell proliferation through EphA2/ephrin-A1 reverse signalling. sEV sorting of EphA2 is increased in senescent cells due to its enhanced phosphorylation resulting from oxidative inactivation of PTP1B phosphatase. Our results demonstrate a novel mechanism of reactive oxygen species (ROS)-regulated cargo sorting into sEVs, which is critical for the potentially deleterious growth-promoting effect of the senescent cell secretome.
Project description:A growing body of evidence in mammalian cells indicates that secreted vesicles can be used to mediate intercellular communication processes by transferring various bioactive molecules, including mRNAs and microRNAs. Based on these findings, we decided to analyze whether T. cruzi-derived extracellular vesicles contain RNA molecules and performed a deep sequencing and genome-wide analysis of a size-fractioned cDNA library (16M-bM-^@M-^S40 nt) from extracellular vesicles secreted by noninfective epimastigote and infective metacyclic trypomastigote forms. Our data show that the small RNAs contained in these extracellular vesicles originate from multiple sources, including tRNAs. In addition, our results reveal that the variety and expression of small RNAs are different between parasite stages, suggesting diverse functions. Taken together, these observations call attention to the potential regulatory functions that these RNAs might play once transferred between parasites and/or to mammalian host cells. Small RNAs profiles (16-40 nt) of epimastigote-derived extracellular vesicles, metacyclic trypomastigote-derived extracellular vesicles and metacyclic trypomastigote parental cells.
Project description:Secreted bacterial RNAs have recently emerged as a novel host-pathogen interaction mode. Naked RNA molecules are highly labile in the extracellular environment and must be protected by packaging into membrane vesicles or into complexes with RNA binding proteins. RNA secretion through membrane vesicles has been shown for several bacterial species but, surprisingly, proteins that bind and stabilize bacterial RNAs in the extracellular environment have not been reported yet. Here, we show that the bacterial pathogen L. monocytogenes secretes a small RNA binding protein that we named Zea. We show that Zea binds and stabilizes a subset of L. monocytogenes RNA, causing its accumulation in the extracellular medium. Zea modulates L. monocytogenes in vivo. Furthemore, Zea binds the mammalian non-self-RNA innate immunity sensor RIG-I and potentiates RIG-I-signaling during infection. This study provides a mechanism for the stability of extracellular RNA and unveils how secreted bacterial RNAs participate in the host-pathogen crosstalk.
Project description:We report small RNA sequencing technology for high-throughput profiling of microRNA content within small extracellular vesicles isolated from nonsenescent and senescent human dermal fibroblasts.
Project description:In this study, we address mRNA composition of hepatocyte-like derived extracellular vesicles (EVs), using as cellular model the mouse liver derived cell line MLP29, and primary cell culture of rat hepatocyte (RH) obtained by in vivo liver perfusion. The study shows qualitative characterization of RNA, identification of transcripts and its functional characterization through gene expression array technique. To reach a deeper nowledge in the biology of EVs, we perform RNase protection assay, density gradients matching RNA with typical exosomal protein markers, and capture assays to probe that mRNA was internalized. Aim of the project: To identify transcripts present in extracellular vesicles secreted by Rat hepatocytes primary cell culture and to identify extracellular vesicles secreted by mouse hepatocyte cell line MLP29, and in this case, compare the enrichment of transcripts respect to the cell, to know if the composition in the extracellular vesicles is similar to the cell, or if their composition is not directly determined by the abundance of transcripts in the cell.
Project description:We report small RNA sequencing technology for high-throughput profiling of microRNA content within small extracellular vesicles isolated from nonsenescent and senescent human umbilical cord mesenchymal stem cells (hUCMSCs)
Project description:Exosomes are small extracellular vesicles released through fusion of multivesicular bodies with the plasma membrane. The aim of this study was to investigate whether there are any differences in miRNAs in exosomes secreted from the prostate cancer cell line PC-3 and in parent cells, as well as to investigate whether there are any differences in miRNAs in cell lysates from PC-3 cells and the non-cancerous prostate cell line RWPE-1. Exosomes isolated from media of PC-3 cells, RNA isolated from exosomes and parent cells, as well as from RWPE-1 cells. Using 3 biological replicates, 1 replicate per array
Project description:Small RNA sequencing of small extracellular vesicles secreted by nonsenescent vs. senescent human umbilical cord mesenchymal stem cells
Project description:To identify the extracellular-vesicle-encapsulated miRNAs that are differentially secreted by the MDA-MB-231 metastatic breast cancer cells following treatment with chemotherapy drugs, we profiled the small RNAs (between 17 and 52 nt) isolated from extracellular vesicles by Illumina sequencing. miRNAs that are significantly induced by chemotherapy drugs are identified.
