Exosomes secreted by a nematode parasite transfer small RNAs to mammalian cells and regulate genes of the innate immune system [Heligmosomoides polygyrus]
ABSTRACT: In mammalian systems, extracellular small RNAs can operate in a paracrine manner to communicate information between cells, relying on transport within vesicles. “Foreign” small RNAs derived from bacteria, plants and parasites have also been detected in mammalian body fluids, sparking interest in whether these could mediate inter-species communication. However, there is no mechanistic framework for RNA-mediated interspecies communication and the active movement of RNA via vesicles has not been shown outside of mammals. Here we demonstrate that specific microRNAs and Y RNAs are packaged into vesicles secreted by a gastrointestinal nematode, Heligmosomoides polygyrus, which naturally infects mice. Total RNA was extracted from the secretion product of adult worms and compared to the profile of small RNAs in adult worms, eggs and infective larvae.
Project description:In mammalian systems, extracellular small RNAs can operate in a paracrine manner to communicate information between cells, relying on transport within vesicles. “Foreign” small RNAs derived from bacteria, plants and parasites have also been detected in mammalian body fluids, sparking interest in whether these could mediate inter-species communication. However, there is no mechanistic framework for RNA-mediated interspecies communication and the active movement of RNA via vesicles has not been shown outside of mammals. Here we demonstrate that specific microRNAs and Y RNAs are packaged into vesicles secreted by a gastrointestinal nematode, Heligmosomoides polygyrus, which naturally infects mice. Total RNA was extracted from the serum of mice infected with Litomosoides sigmodontis at 60 days post infection
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 (16–40 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:Exosomes and microvesicles (i.e., extracellular vesicles; EVs) have been identified within ovarian follicular fluid, and recent evidence suggests that EVs are able to elicit profound effects on ovarian cell function. While existence of miRNA within EVs has been reported, it remains unknown if EV size and concentration as well as their cargos (i.e., proteins and RNA) change during antral follicle growth. Extracellular vesicles isolated from follicular fluid of small, medium and large bovine follicles were similar in size, while concentration of EVs decreased progressively as follicle size increased. Electron microscopy indicated a highly purified population of the lipid bilayer enclosed vesicles that were enriched in exosome biomarkers including CD81 and Alix. Small RNA sequencing identified a large number of known and novel miRNAs that changed in the EVs of different size follicles. Ingenuity Pathway Analysis (IPA) indicated that miRNA abundant in small follicle EV preparations were associated with cell proliferation pathways, while those miRNA abundant in large follicle preparations were related to inflammatory response pathways. These studies are the first to demonstrate that EVs change in their levels and makeup during antral follicle development and point to the potential for a unique vesicle-mediated cell-to-cell communication network within the ovarian follicle. Examination of small RNA population in bovine follicular fluid extracellular vesicles isolated from antral follicles
Project description:MicroRNA and other types of small regulatory RNAs play a crucial role in the regulation of gene expression in eukaryotes. Several distinct classes of small regulatory RNAs have been discovered in recent years. To extend the repertoire of small regulatory RNAs characterized in mammals and identify miRNA expressed upon viral infection we used Illumina’s ultrahigh throughput sequencing approach. Results presented in this study extend our knowledge of the biology and evolution of small regulatory RNAs in mammals and illuminate mechanisms of small RNA biogenesis and function. Keywords: Transcriptome analysis We sequenced three small RNA libraries prepared from cell line derived from the adult bovine kidney under normal conditions and upon infection of the cell line with the bovine herpesvirus 1.
Project description:Breast milk is a complex liquid that enriched in immunological components and affect the development of the infant immune system. Exosomes, the membranous vesicles of endocytic origin, are ubiquitously in various body fluids which can mediate intercellular communication. MicroRNAs (miRNAs), a well-defined group of non-coding small RNAs, in human breast milk are packaged inside exosomes. Here, we present the identification of miRNAs in human breast milk exosomes using deep sequencing technology. We found that the immune-related miRNAs are enriched in breast milk exosomes, and are resistant to the general harsh conditions. Four small RNA libraries in human breast milk exosomes from four healthy women (30 +/- 0.9 years old, primiparity) when the infant were aged at 60 days were sequenced.
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:Small RNAs, such as miRNAs and siRNAs, are involved in gene regulation in a variety of systems, including mouse oocytes. Dicer is a ribonuclease III enzyme essential for miRNA and siRNA biosynthesis. In an effort to uncover the function of small RNAs during oocyte growth, we specifically deleted Dicer in growing oocytes and analyzed the global pattern of gene expression in these Dicer-deficient oocytes. Germinal vesicle-intact, fully grown oocytes were collected from eCG-primed wild-type or Dicer-deficient female mice and freed of attached cumulus cells by pipetting. Twenty oocytes per mouse were used for RNA extraction and hybridization on the MOE430 v2 Affymetrix microarray platform. Oocytes from four wild-type and four Dicer-knockout mice were analyzed.
Project description:Exosomes/microvesicles (hereafter referred to as extracellular vesicles) were isolated from the ULF of day 14 cyclic and pregnant ewes using ExoQuick-TC. Extracellular vesicle RNA was pooled (n=4 per status) and analyzed for small RNAs by sequencing on the Ion Torrent PGM platform and analysis with CLC Genomics Workbench small RNA workflow based on the miRBase (Release 19) Bos taurus database. Small RNA analysis of day 14 uterine luminal fluid extracellular vesicles isolated from pregnant and cyclic ewes.
Project description:MicroRNAs (miRNAs) are a class of small RNA molecules that regulate expression of specific mRNA targets. They can be released from cells, often encapsulated within extracellular vesicles (EVs), and therefore have the potential to mediate intercellular communication. It has been suggested that certain miRNAs may be selectively exported, although the mechanism has yet to be identified. Manipulation of the miRNA content of EVs will be important for future therapeutic applications. We therefore wished to assess which endogenous miRNAs are enriched in EVs and how effectively an overexpressed miRNA would be exported. Small RNA libraries from HEK293T cells and vesicles before or after transfection with a vector for miR-146 overexpression were analysed by deep sequencing. A subset of miRNAs was found to be enriched in EVs. The global expression data provided by deep sequencing confirms that specific miRNAs are enriched in EVs released by HEK293T cells. Cells were transfected with a plasmid to direct overexpression of miR-146a. Extracellular vesicles were isolated by ultracentrifugation from untreated and transfected cells. RNA was isolated from one sample each of untreated and transfected cells and vesicles.Small RNA libraries were prepared for sequencing.