Role of transglutaminase 2 in promoting biglycan synthesis in idiopathic gingival fibromatosis.

Background: This study aimed to elucidate the pathogenesis of idiopathic gingival fibromatosis (IGF). Methods: Human gingival fibroblasts (hGFs) were isolated from patients with IGF and periodontitis. Differential gene expression in the hGFs was analyzed using RNA sequencing. Extracellular matrix-related gene expression in the hGFs was analyzed. The effect of specific protein (SP)1 inhibitor or recombinant human transglutaminase 2 (rh-TGM2) on biglycan (BGN) expression in hGFs was also determined. Results: RNA sequencing showed that TGM2 expression was downregulated and BGN mRNA expression was upregulated in patients with IGF relative to periodontitis. rh-TGM2 stimulation of hGFs in patients with IGF significantly reduced BGN expression. SP1 inhibitors downregulated BGN expression in the hGFs. Conclusion: BGN upregulation via SP1 causes TGM2 downregulation in gingival fibroblasts in IGF. [ABSTRACT FROM AUTHOR]