Abstract This study aimed to investigate whether GSK-3 inhibition (CHIR99021) effectively promoted mineralization by cementoblasts (OCCM-30). OCCM-30 cells were used and treated with different concentrations of CHIR99021 (2.5, 5, and 10 mM). Experiments included proliferation and viability, cellular metabolic activity, gene expression, and mineral nodule formation by Xylene Orange at the experimental time points. In general, CHIR99021 did not significantly affect OCCM-30 viability and cell metabolism (MTT assay) (p > 0.05), but increased OCCM-30 proliferation at 2.5 mM on days 2 and 4 (p < 0.05). Data analysis further showed that inhibition of GSK-3 resulted in increased transcript levels of Axin2 in OCCM-30 cells starting as early as 4 h, and regulated the expression of key bone markers including alkaline phosphatase (Alp), runt-related transcription factor 2 (Runx-2), osteocalcin (Ocn), and osterix (Osx). In addition, CHIR99021 led to an enhanced mineral nodule formation in vitro under both osteogenic and non-osteogenic conditions as early as 5 days after treatment. Altogether, the results of the current study suggest that inhibition of GSK-3 has the potential to promote cementoblast differentiation leading to increased mineral deposition in vitro. GSK3 GSK 3 GSK- CHIR (CHIR99021 OCCM30. OCCM30 OCCM 30 . (OCCM-30) OCCM-3 CHIR9902 2.5, 25 (2.5 1 mM. mM) activity points general MTT assay p 0.05, 005 0.05 , 0 05 0.05) 2. 0.05. Axin h Alp, Alp (Alp) runtrelated runt related Runx2, Runx2 Runx (Runx-2) Ocn, Ocn (Ocn) Osx. Osx (Osx) addition nonosteogenic non treatment Altogether (CHIR9902 OCCM3 (OCCM-30 OCCM- CHIR990 (2. 00 0.0 (Alp (Runx-2 (Ocn (Osx (CHIR990 (OCCM-3 CHIR99 (2 0. (Runx- (CHIR99 (OCCM- CHIR9 ( (Runx (CHIR9 (OCCM (CHIR

Resumo Apesar de a periodontite ser uma das doenças infecto inflamatórias humanas mais comuns, os mecanismos que conduzem à imunopatologia não estão bem definidos. Inúmeras moléculas induzem atividade inflamatória que levam à perda óssea. Para que haja a reabsorção óssea, células monocíticas são ativadas e se transformam em osteoclastos. As moléculas TACE (Enzima conversora de TNF-α) e DC-STAMP (Proteína transmembrana específica de célula dendrítica) parecem atuar no processo de reabsorção óssea uma vez que a TACE induz a liberação de sRANKL (ativador do receptor do fator nuclear kappa-β ligante solúvel), enquanto a DC-STAMP é um fator chave na indução dos osteoclastos. Diante disso, o presente estudo avaliou a expressão gênica das moléculas TACE e DC-STAMP em pacientes com e sem periodontite uma vez que o papel destas moléculas no curso do desenvolvimento da periodontite ainda é pouco explorado. Foram selecionados 20 indivíduos, sendo 10 com saúde periodontal e com indicação para remoção de tecido gengival por motivos estéticos e 10 pacientes com periodontite. As análises da expressão das moléculas no tecido gengival foram realizadas por meio de western blotting. Os níveis proteicos tanto de TACE quanto de DC-STAMP, foram maiores nos tecidos do grupo com periodontite em comparação aos do grupo controle (p<0.05; Student' t-test). Portanto, os dados demonstram que a expressão protéica das moléculas TACE e DC-STAMP estão elevados em pacientes com periodontite, favorecendo a progressão da reabsorção óssea nesta patologia.

Abstract Although periodontitis is one of the commonest infectious inflammatory diseases in humans, the mechanisms involved with its immunopathology remain ill understood. Numerous molecules may induce inflammation and lead to bone resorption, secondary to activation of monocytes into osteoclasts. TACE (TNF-α converting enzyme) and DC-STAMP (dendritic cell-specific transmembrane protein) appear to play a role on bone resorption since TACE induces the release of sRANKL (soluble receptor activator of nuclear factor kappa-β ligand) whereas DC-STAMP is a key factor in osteoclast induction. The present study evaluated the levels of TACE and DC-STAMP in patients with and without periodontitis. Twenty individuals were selected: 10 periodontally healthy participants undergoing gingivectomy for esthetic reasons and 10 diagnosed with periodontitis. Protein levels of such molecules in gingival tissue were established using Western blotting. Protein levels of both TACE and DC-STAMP were higher in the periodontitis group than in the control group (p<0.05; Student t-test). In conclusion, TACE and DC-STAMP protein levels are elevated in patients with periodontitis, favoring progression of bone resorption.