Project description:Communication between the maternal uterus and the embryo is vital for a successful pregnancy. Exosomes, subtypes of extracellular vesicles comprising many bioactive factors regulate the early stages of pregnancy, specifically during embryo implantation. Nevertheless, the mechanism by which exosomal microRNAs (miRNAs) derived from placental trophoblasts regulate embryo implantation remains elusive. Herer, we isolated and identified exosomes derived from placental trophoblasts cells (HTR8/SVneo). Subsequently, we evaluated the loading miRNA in exosomes by small RNA sequencing. This study provides novel insights into the mechanism of trophoblasts cells-derived exosomes during embryo implantation.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:miRNA-sequencing of grapefruit-derived extracellular vesicles and fusion nanovesicles derived from grapefruit-derived extracellular vesicles and gingival mesenchymal stem cell-derived vesicles. We then performed gene expression profiling analysis to explore the miRNAs derived from grapefruit-derived extracellular vesicles, and the retention rate of miRNAs after membrane fusion
Project description:To gain insight into the microRNA expression profile of small extracellular vesicles derived from bone metabolism related cell types and to verify their mechanism, we utilized the miRNA sequencing technology to analyze the miRNA profiles of different mouse osteoblast and osteoclast cell derived small extracellular vesicles.
Project description:We report the differential abundance of cell free miRNAs extracted from extracellular vesicles (EV) in the peripheral blood of pregnant women with or without preeclampsia by Next Generation Sequencing. Maternal blood samples were collected form pregnant women enrolled in the study during first to very early second trimester (11–14 weeks ), mid- to late second trimester (19–22 weeks), third trimester (36 weeks) and at delivery. Extracellular vesicles were isolated from peripheral blood and total RNA was extracted using the miRNeasy Mini Kit (Qiagen, Valencia, CA) following manufacturer’s instruction. miRNA libraries were prepared utilizing NEB Next Multiplex small RNA Library prep kit (NEB E7300S; New England Biolabs, Inc, Ipswich, MA, USA) and libraries were subsequently sequenced using the HiSeq-2500 platform with single-end 50bp reads (Illumina Inc.; San Diego, CA, USA).
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.