Project description:Assessment of the putative differential gene expression profiles in high osmolality-treated bovine nucleus pulposus intervertebral disc cells for a short (5 h) and a long (24 h) time period. Identification of novel genes up- or down-regulated as an early or a late response to hyperosmotic stress. A 5 and 24 h-hyperosmotic treatment of nucleus pulposus cells led to transcriptional changes in >100 and 200 genes, respectively. Nucleus pulposus intervertebral disc cells were exposed to hyperosmotic stress for 5 and 24 h before RNA extraction and transcriptomics analysis. Three biological replicates were tested for each condition. Selected genes found to be differentially expressed were validated by RT-qPCR. Functional experiments were performed in order to assess the role of specific proteins encoded by genes found to be up-regulated in the osmo-reguatory response of intervertebral disc cells.
Project description:With regulatory roles in development, cell proliferation and disease, micro-RNA (miRNA) biology is of great importance and a potential key to novel RNA-based therapeutic regimens. Biochemically based sequencing approaches have provided robust means of uncovering miRNA binding landscapes on transcriptomes of various species. However, a current limitation to the therapeutic potential of miRNA biology in cattle is the lack of validated miRNAs targets. Here, we use cross-linking immunoprecipitation (CLIP) of the Argonaute (AGO) proteins and unambiguous miRNA-target identification through RNA chimeras to define a regulatory map of miRNA interactions in the cow (Bos taurus). The resulting interactome is the deepest reported to date for any species, demonstrating that comprehensive maps can be empirically obtained. We observe that bovine miRNA targeting principles are consistent with those observed in other mammals. Motif and structural analyses define expanded pairing rules with most interactions combining seed-based pairing with distinct, miRNA-specific patterns of auxiliary pairing. Further, miRNA-target chimeras had predictive value in evaluating true regulatory sites of the miR-17 family. Finally, we define miRNA-specific targeting for >5000 mRNAs and determine gene ontologies (GO) for these targets. This confirmed repression of genes important for embryonic development and cell cycle progress by the let-7 family, and repression of those involved in cell cycle arrest by the miR-17 family, but it also suggested a number of unappreciated miRNA functions. Our results provide a significant resource for transcriptomic understanding of bovine miRNA regulation, and demonstrate the power of experimental methods for establishing comprehensive interaction maps.
Project description:The aim of this transcription profiling study was to identify novel genes that could be used to distinguish bovine Nucleus pulposus (NP) cells from articular cartilage (AC) and annulus fibrosus (AF) cells and to further determine their expression in normal and degenerate human intervertebral disc (IVD). This study has identified a number of novel genes that characterise the bovine and human NP and IVD cell phenotypes and allows for discrimination between AC, AF and NP cells.<br><br>