Microparticles

1. Microparticles Microparticles (microvesicles) are submicron-sized extracellular vesicles, that are released from plasma cell membrane during cell activation or apoptosis and differ from other types of extracellular vesicles (exosomes, apoptotic bodies) in their size, mechanism of formation, composition and function. Being long overlooked as »cellular dust« without any function, microparticles have gained an extensive research interest and biological significance during the last decade as novel vectors of intercellular communication and potential novel disease-specific effectors and biomarkers. Elevated numbers and altered composition of microparticles have been detected in body fluids of patients with cancer, cardiovascular, inflammatory and autoimmune disorders, including sepsis, coronary artery disease, vasculitis, multiple slcerosis, systemic lupus erythematosus and rheumatoid arthritis. Accumulating evidence indicates that microparticles can transfer between cells several different biologically active molecules, including microRNAs, thereby epigenetically reprogramming the target cells within cell microenvironments. The aims of our research project are 1. to identify the specific expression patterns of microRNAs in microparticles derived from resident synovial cells of patients with rheumatoid arthritis and 2. to elucidate the functional role of microparticle-derived microRNA in intercellular communication within rheumatoid joints as well as their participation in the pathogenesis of rheumatoid arthritis. Project: Astrid Jüngel, PhD, PD Mojca Frank, MD, PhD