Project description:The aim of the study was to investigate whether the trefoil peptide genes, in concerted action with a miRNA regulatory network, were contributing to nutritional maintrenance. Using a Tff2 knock-out mouse model, 48 specific miRNAs were noted to be significantly deregulated when compared to the wild type strain.
Project description:The aim of the study was to investigate whether the trefoil peptide genes, in concerted action with a miRNA regulatory network, were contributing to nutritional maintrenance. Using a Tff3 knock-out mouse model, 21 specific miRNAs were noted to be significantly deregulated when compared to the wild type strain.
Project description:Foxp3+ regulatory T (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely . Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of inter-cellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA-biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg cell-mediated suppression mediated by miRNA-containing exosomes. Regulatory T cells (CD4+CD25hiFoxp3rfp+, Treg) were isolated from naive mice. RNA as extracted form some Treg cells, while others were cultured in complete IMDM media for 3 days, stimulated with anti-CD3 anti-CD3 (1ug/ml) and anti-CD28 (10ug/ml). Exosomes were recovered from Treg cell supernatant, as described, and RNA was extracted form the purified exosomes. To identify which miRNAs were transferred to Dicer-deficient (KO) cells from Treg cells, we cultured Dicer KO cells alone, or co-cultured Dicer KO cells with Treg cells. RNA was extracted form Dicer KO cells cultured alone or from Dicer KO cells cultured in the presence of Treg cells. 3 x biological replicates were used. Each biological replicate was derived from a pool of 3-5 samples.
Project description:Most cancer-related deaths are caused by distant metastases, which are tumour cells that have escaped from a primary tumour and passed into the bloodstream to colonize a new organ. In this context, communication between tumour and stromal cells is essential. Indeed, tumor cells interact with cells in the tumor microenvironment and are able to modify them to their advantage. Both extracellular vesicles (EVs) and exosomes are heterogeneous populations of small vesicles present in the tumor microenvironment and in body fluids that have recently emerged as powerful mediators involved in this communication and their transport in fluids. Tumor cells release large quantities of exosomes containing tumor markers, which can then spread to distant locations.
The exosomes are of endosomal origin. They are composed of proteins, lipids, RNA and DNA, and they circulate in the bloodstream. They can be internalized by specific distant cells and thus deliver a functional message. It has recently been shown that tumor exosomes containing pro-metastatic factors form pre-metastatic niches, before the tumor cells actually arrive, while determining the metastatic organotropism of tumors. These properties are now opening up new avenues of research in tumor biomarkers. In recent years, several studies have highlighted different markers contained specifically in exosomes derived from cancer cells. Consequently, exosomes are considered as potential reservoirs of tumor biomarkers that could be clinically useful for the non-invasive diagnosis of cancer, with the advantage of being performed by liquid biopsy. The study of microRNA (miRNA) is of particular interest. Indeed, miRNAs are small non-coding RNAs (between 21 and 25 nucleotides) involved in the regulation of gene expression and which are frequently deregulated in cancer. Several studies underline that the variation of free miRNAs in the blood is correlated with the progression of the disease, particularly in colon cancer. However, the stability of free miRNAs is controversial. Therefore, exosomes represent a very advantageous means of transporting miRNAs in the blood, as they are able to protect miRNAs from degradation by RNAase.
The hypothesis of the project is that circulating exosomes derived from tumours contain markers including specific miRNAs that could be used as biomarkers of early prognosis (survival and progression), easily measured in blood samples from patients with colon cancer. But other molecules contained in exosomes could also be of interest.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)