Project description:We investigate the therapeutic effect of mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs), a potent immune-modulating therapy for tissue regeneration, in repairing optic nerve damage. Intraocular administration of MSC-sEVs promotes both RGC survival and axon regeneration against optic nerve crush injury. Mechanistically, MSC-sEVs recruits a neural restorative population of hematogenous Ly6Clow monocyte/monocyte-derived macrophage (Mo/MΦ). Gain-of-function by intravitreal administration of the donor Ly6Clow Mo/MΦ markedly improves neurological outcomes in vivo. We then performed gene expression profiling analysis using data obtained from RNA-seq of 4 different cells at two time points.
Project description:Small extracellular vesicles (sEVs), 50-150 nm in diameter, have been proposed to mediate cell-cell communication with important implications in tumor microenvironment interactions, tumor growth, and metastasis. We previously showed that mutant KRAS colorectal cancer (CRC) cells release sEVs containing Rab13 protein and mRNA. Previous work had shown that disruption of intracellular Rab13 trafficking inhibits epithelial cell proliferation and invasiveness. Here, we show that Rab13 additionally regulates the secretion of sEVs corresponding to both traditional exosomes and a novel subset of vesicles containing both β1-integrin and Rab13. We find that exposure of recipient cells to sEVs from KRAS mutant donor cells increases proliferation and tumorigenesis and that knockdown of Rab13 blocks these effects. Thus, Rab13 serves as both a cargo protein and as a regulator of sEV secretion. Our data support a model whereby Rab13 can mediate its effects on cell proliferation and invasiveness via autocrine and paracrine signaling.
