Depletion of miR-155 hinders the myofibroblast activities and reactive oxygen species generation in oral submucous fibrosis

Background/purpose: Emerging evidence suggests the significance of microRNA-155 (miR-155) in fibrogenesis and oxidative stress accumulation, but its function in oral submucous fibrosis (OSF) has not been investigated. In this study, we assessed the expression of miR-155 and its effects on the maintenance of myofibroblast activation. Methods: qRT-PCR was conducted to assess the expression of miR-155 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF samples. Collagen gel contraction, migration, and invasion capabilities were examined in fBMFs. DCFDA ROS assay was used to examine ROS generation. A luciferase reporter assay was carried out to verify the relationship between miR-155 and its potential target RPTOR. Results: We showed that the expression of miR-155 was aberrantly upregulated in OSF specimens and fBMFs. Inhibition of miR-155 ameliorated various myofibroblast activities, including collagen gel contraction, migration, and invasion abilities as well as ROS production. Results from the luciferase reporter assay demonstrated that miR-1 55 directly interacted with its target RPTOR. Conclusion: Taken together, these findings indicate that miR-155 is implicated in the patho-genesis of oxidative stress-associated OSF, possibly through the regulation of RPTOR. Copyright (c) 2021, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study reveals the aberrant upregulation of miR-155 in oral submucous fibrosis and shows that inhibition of miR-155 can improve fibroblast activities and oxidative stress. miR-155 may be involved in fibrogenesis through the regulation of RPTOR.