Résumé

<p>Abstract. The aim of this study was to examine the level and&nbsp;<br>basic characteristics of cell-derived microparticles (MPs) in&nbsp;<br>the cyst fluids of odontogenic keratocysts (OKCs). For this&nbsp;<br>purpose, MPs from the cyst fluids (CFMPs) of OKCs were&nbsp;<br>purified by a classic differential centrifugation method and&nbsp;<br>characterized by a transmission electron microscope and&nbsp;<br>fluorescence microscope. Flow cytometric analysis was used&nbsp;<br>to determine the size, concentration and cellular origins of the&nbsp;<br>CFMPs. Moreover, the expression level of receptor activator&nbsp;<br>for nuclear factor-κB ligand in the OKCs was evaluated by&nbsp;<br>immunohistochemical staining and then analyzed for its corre-<br>lation with the concentration of CFMPs by Spearman's rank&nbsp;<br>correlation test. In addition, reverse transcription‑quantitative&nbsp;<br>polymerase chain reaction (RT‑qPCR) and tartaric‑resistant&nbsp;<br>acid phosphatase (TRAP) staining were performed to examine&nbsp;<br>the osteoclastogenesis of mouse bone marrow‑derived macro-<br>phages (BMMs) in response to CFMPs. The results revealed&nbsp;<br>that the levels of total CFMPs were significantly elevated in&nbsp;<br>OKCs compared with dentigerous cysts (DCs) and radicular&nbsp;<br>cysts (RCs). In addition, in vitro experiments further revealed&nbsp;<br>that CFMPs derived from the OKCs of patients could be&nbsp;<br>taken up by BMMs, leading to a significant increase in the&nbsp;<br>mRNA expression levels of nuclear factor of activated&nbsp;<br>T‑cells 1 (NFATc1) and TRAP. Moreover, TRAP‑positive&nbsp;<br>multinucleated osteoclasts were successfully cultured in the&nbsp;<br>presence of macrophage colony‑stimulating factor (M‑CSF)&nbsp;<br>and CFMPs with BMMs. On the whole, our findings indicate&nbsp;<br>that patients with OKCs have higher levels of CFMPs compared&nbsp;<br>with patients with DCs and RCs, which may be associated with&nbsp;<br>the bone resorption of OKCs. De</p>