Biological Function of Exosome-like Particles Isolated from Rose (Rosa Damascena) Stem Cell Culture Supernatant

Rose stem cell (RSC) extracts have been claimed to have multiple beneficial effects in skin. Many cells release extracellular vesicles, also called exosomes, that involved in cell-to-cell communication. There is however no information on whether exosomes are released in RSC cultures, and what the biological function of these may be. We hypothesized that RSC in culture can release exosome-like particles (RSCEs) and that the RSCEs may have biological function in cells relevant to skin. RSC culture supernatant was purchased and standard exosome-isolation was performed, using tangential flow filtration. The characterization of RSCEs was measured with TEM and NTA, that revealed round structures and reports the presence of particles approximate 90-200nm size. Proteins and miRNAs were isolated from the exosomes, and 206 peptides containing likely cytosolic and membrane proteins and miRNA containing Let-7 families were identified. The RSCEs were found to be non-toxic on human dermal papilla cells, whereas a high concentration of the crude supernatant induced widespread cell death. Further, the RSCEs enhanced growth of human dermal fibroblasts and increased the closure of scratch assay, whereas the crude supernatant lacked this effect. Further, the RSCEs reduce the amount of melanin in cultured melanocytes and IL-6 released by Raw264.7 cells stimulated by LPS in a dose-dependent manner. These data collectively show that RSC in culture released RSCEs that contain miRNA and proteins have multiple biological functions in skin-related assays such as fibroblast growth and melanin content in melanocytes. Combined with the anti-inflammatory function of the RSCEs, we suggest that they have appropriate features to be useful in aesthetic medicine for improving skin quality.