Emdogain-Regulated Gene Expression in Palatal Fibroblasts Requires TGF-βRI Kinase Signaling

Abstract

Genome-wide microarrays have suggested that Emdogain regulates TGF-β target genes in gingival and palatal fibroblasts. However, definitive support for this contention and the extent to which TGF-β signaling contributes to the effects of Emdogain has remained elusive. We therefore studied the role of the TGF-β receptor I (TGF-βRI) kinase to mediate the effect of Emdogain on palatal fibroblasts. Palatal fibroblasts were exposed to Emdogain with and without the inhibitor for TGF-βRI kinase, SB431542. Emdogain caused 39 coding genes to be differentially expressed in palatal fibroblasts by microarray analysis (p<0.05; >10-fold). Importantly, in the presence of the TGF-βRI kinase inhibitor SB431542, Emdogain failed to cause any significant changes in gene expression. Consistent with this mechanism, three independent TGF-βRI kinase inhibitors and a TGF-β neutralizing antibody abrogated the increased expression of IL-11, a selected Emdogain target gene. The MAPK inhibitors SB203580 and U0126 lowered the impact of Emdogain on IL-11 expression. The data support that TGF-βRI kinase activity is necessary to mediate the effects of Emdogain on gene expression in vitro.

Collagen Membranes Adsorb the Transforming Growth Factor‐β Receptor I Kinase‐Dependent Activity of Enamel Matrix Derivative

“…The current authors recently demonstrated that EMD regulates TGF‐β target genes in gingival and palatal fibroblasts 20 . Consistent with these findings, TGF‐β receptor I (TGF‐βRI) kinase inhibitors abrogated the effect of EMD on: 1) expression of TGF‐β target genes, 21 2) adipogenesis, 22 and 3) osteoclastogenesis 23 . Further evidence that EMD provokes TGF‐β‐ related responses comes from TGF‐β‐neutralizing antibodies that substantially reduced the impact of EMD on: 1) cell signaling, 24 2) connective tissue growth factor expression, 25 and 3) proliferation 26 .…”

“…Another study reported on an interaction of amelogenin with glucose‐regulated protein 78 to control cell proliferation 30 . Positive signals for TGF‐β have been achieved with immunoassay but not proteomics 21 . However, proteomics can be used to screen for components of EMD adsorbing to collagen.…”

Inhibitors of DNA methylation support TGF-β1-induced IL11 expression in gingival fibroblasts

“…That protocol [39] also increased the expression of TGF-β, and it would be possible to carry out a feed-forward stimulation of this signaling pathway. There is a demand for preclinical studies testing whether 5-aza can support periodontal regeneration following conventional scaling and root planning, and also following regenerative strategies based on local applications of recombinant growth factors and enamel matrix derivatives, particularly because the latter preparations exert a TGF-β-like activity [40]. Also of interest are investigations into the impact of periodontal disease on the methylation status of promoter regions regulating extracellular matrix molecules [29], chemokines and cytokines [30], and signaling molecules [31].…”

Acid bone lysate activates TGFβ signalling in human oral fibroblasts

“…Bioassays with TGF-β-responsive cells are appropriate to determine TGF-β activity in ABL. We previously used oral fibroblasts to detect TGF-β1 activity in supernatants of freshly prepared bone chips 17 and enamel matrix derivatives 18 . Moreover, the adsorption of TGF-β1 from these preparations to collagen matrices commonly used for guided bone regeneration was determined by gene expression changes of oral fibroblasts 19 , 20 .…”