Adipocyte-derived microvesicles contain RNA that is transported into macrophages and might be secreted into blood circulation

We have recently found that 3T3-L1 adipocytes secrete microvesicles, known as adipocyte-derived microvesicles (ADMs), with angiogenic activity. In this study, we found that ADMs contain RNA without typical 28S and 18S ribosomal RNA inside the vesicles. Microarray analysis revealed that ADMs contain approximately 7000 mRNAs and 140 microRNAs. Most of transcripts for adipocyte-specific and dominant genes were contained in the ADMs, and their abundance was mostly correlated with that in the donor cells. Abundance of adipocyte-related microRNAs was also mostly correlated with that in the donor cells. ADMs mediated transport of adiponectin and resistin gene transcripts into RAW264.7 macrophages. Moreover, adipocyte-specific gene transcripts such as adiponectin, resistin, and PPARγ2 were found in microvesicles isolated from rat serum. Thus, ADM might play a role as a novel intercellular communication tool by transporting RNA in paracrine and possibly endocrine manners.