Secretory microRNA-29 expression in gingival crevicular fluid during orthodontic tooth movement

Abstract

Secretory microRNAs (miRNAs) have been used increasingly as biomarkers for cancers, autoimmune diseases and inflammatory diseases. They are reported as being freely circulated or encapsulated in microvesicles such as exosomes. This study was performed to elucidate the presence of miRNAs with exosomes in human gingival crevicular fluid (GCF), and the expression profile of miRNA-29 during orthodontic tooth movement. Four healthy volunteer and fifteen orthodontic patients were enrolled in the study. Secretory miRNA in GCF was collected and analyzed using a bioanalyzer, realtime PCR and Western blot analysis. The expression profile of secretory miR-29 family in GCF was analyzed during the course of canine retraction for 6 weeks. The results demonstrated the presence of miRNAs in the GCF. After series of ultracentrifugation and RT-PCR array, exosome-depleted fractions and pellets were isolated and we found that secretory miRNAs were detected in both the exosome-associated fraction and the exosome-depleted supernatant fraction; however, the concentration of miRNAs was higher in the exosome-associated fraction than in the exosome-depleted fraction suggesting a close association between the secretory miRNAs and exosomes in GCF. We also demonstrated the increased expression profiles of miR-29 family during six weeks of orthodontic tooth movement in humans. Secretory miRNAs are present in GCF and secretory miRNA-29 family expression profiles increase during the tooth movement in humans. Secretory miRNA-29 in GCF could serve as potential biomarkers for periodontal remodeling.

Extracellular vesicle identification in tooth movement models

“…These data raised the possibility that GCF is rich in EVs. This was confirmed by Atsawasuwan et al Their study showed by electron microscopy the presence of EVs in GCF. The EVs in GCF could be pelleted by ultracentrifugation and contained markers commonly found in EVs, including microRNAs, CD9 and CD63.…”

“…Several markers for EVs involved in regulating bone remodelling have been identified. These include receptor activator of nuclear factor kappa B‐ligand (RANKL), RANK, semaphorin 4B, ephrinA2, microRNA (miR)‐214‐3p, miR‐29, and miR‐146a‐5p . Protein biomarkers could be detected by immunogold electron microscopy in alveolar bone associated with OTM models.…”

Clastic cells in orthodontic treatment: Translational challenges and recent advances

“…However, these methods usually detect the problem at an advanced stage where significant tissue damage had occurred. Rather, the expression of biomarkers in GCF has been recognized as a promising non‐invasive tool for clastic cell activity surveillance during orthodontic treatment . Gingival crevicular fluid is defined as a transudate of interstitial fluid and/or inflammatory exudate.…”

“…Although the sample size of 11 subjects was relatively small and exosomes were not directly observed, this study pioneered the exploration of exosomes in GCF research. More recently, a study published by Atsawasuwan et al provided direct evidence that exosome tracking may be a suitable alternative to monitor osteoclast activity in GCF during tooth movement. These advances open a new window of opportunity in the discovery of novel biomarkers of mineralized tissue resorption.…”

“…Studies have emerged in recent years showing that exosomes secreted by clastic cells may be involved in the regulation of bone remodelling and dentin resorption . Exosomes are minute vesicles (30‐150 nm in diameter) that can be found in saliva and gingival crevicular fluid (GCF) . Thus, the assessment of mineralized tissue resorption using biofluids is an important research topic since it may allow for the development of non‐invasive methods to monitor bone and dentin resorption over time.…”