Silencing periostin inhibits myofibroblast transdifferentiation of fibrotic buccal mucosal fibroblasts

Targeting histone deacetylase 9 represses fibrogenic phenotypes in buccal mucosal fibroblasts with arecoline stimulation

Background/purpose

Oral submucosal fibrosis (OSF) is a premalignant disorder positively associated with betel nut chewing. Recent studies supported the promising benefits of histone deacetylase (HDAC) inhibitors for fibrosis treatment. Here we aim to clarify the pro-fibrogenic role of HDAC9 in regulating OSF.

Materials and methods

Healthy and OSF specimens were collected to investigate the clinical significance of HDAC9. Chronic arecoline treatment process was used to induce arecoline-mediated myofibroblasts-related activation of primary buccal mucosa fibroblasts (BMFs). Functional analysis of collagen gel contraction, transwell migration, and wound-healing assays were performed to assess the change in pro-fibrogenic properties of BMFs and fibrotic BMFs (fBMFs). Lentiviral-mediated HDAC9 knockdown was used to verify the role of HDAC9 in the pro-fibrogenic process.

Results

We found that arecoline significantly increased the mRNA and protein expression of HDAC9 of BMFs in a dose-dependent manner. Knockdown of HDAC9 in BMFs reversed the strengthened effects of arecoline on collagen gel contraction, cell migration, and wound-healing ability. We further demonstrated that knockdown of HDAC9 in fBMFs significantly attenuated its inherent pro-fibrogenic properties. Furthermore, we confirmed a significantly increased expression of HDAC9 mRNA in OSF compared to normal tissues, which suggested a positive correlation between the up-regulation of HDAC9 and OSF.

Conclusion

We demonstrated that silencing of HDAC9 inhibited arecoline-induced activation and inherent pro-fibrogenic properties, suggesting potential therapeutics by targeting HDAC9 in the OSF treatment.

Downregulation of histone deacetylase 8 (HDAC8) alleviated the progression of oral submucous fibrosis

Background/purpose

Oral submucous fibrosis (OSF) is a premalignant disorder that is associated with betel nut chewing. The purpose of the study was to establish the role of histone deacetylase (HDAC) 8, one of histone deacetylases, in the regulation of fibrotic conditions to provide a therapeutic potential for OSF.

Materials and methods

First, we examined the expression of HDAC8 in fibrotic buccal mucosal fibroblasts (fBMFs) and OSF tissues. Markers of myofibroblasts and TGF-β signaling were conducted in fBMFs with HDAC8 knockdown were examined. Furthermore, epithelial-mesenchymal transition (EMT) markers, collagen gel contraction and migration ability were also examined in fBMFs transfected with sh-HDAC8. HDAC8 inhibitor was used to analyze the collagen gel contraction and wound healing ability in fBMFs.

Results

We observed the mRNA expression of HDAC8 was significantly increased in fBMFs. Compared to normal tissues, the protein level of HDAC8 was upregulated in OSF. Next, mRNA and protein expression of HDAC8 was significantly decreased, accompanying downregulation of α-SMA and COL1A1 in fBMFs infected with sh-HDAC8. To determine the critical role of HDAC8 in OSF fibrogenesis, results revealed that TGF-β secretion and the expression of EMT transcription factor SNAIL and p-Smad were significantly decreased in HDAC8-knockdown fBMFs. We further demonstrated that collagen gel contraction and migration ability were significantly decreased in fBMFs transfected with sh-HDAC8. Last, results revealed that significantly reduced collagen gel contraction and wound healing ability in fBMFs with HDAC8 inhibitor treatment.

Conclusion

We concluded that downregulation of HDAC8 alleviated the activities of myofibroblasts and TGF-β/Smad signaling pathway in OSF.