Frizzled 6 disruption suppresses osteoblast differentiation induced by nanotopography through the canonical Wnt signaling pathway
Rodrigo Paolo Flores Abuna, Fabíola Singaretti Oliveira, Letícia Faustino Adolpho, Roger Rodrigo Fernandes, Adalberto Luiz Rosa, Márcio Mateus Beloti
Abstract
Abstract This study aimed to investigate if wingless‐related integration site (Wnt) signaling participates in the high osteogenic potential of titanium with nanotopography (Ti‐Nano). We showed that among the several components of the Wnt signaling pathway, Frizzled 6 ( Fzd6 ) was the transcript most intensely modulated by nanotopography compared with the untreated Ti surface (Ti‐Machined). Then, we investigated whether and how Fzd6 participates in the regulation of osteoblast differentiation caused by nanotopography. The Fzd6 silencing with CRISPR–Cas9 transfection in MC3T3‐E1 cells induced a more pronounced inhibition of osteoblast differentiation of cells cultured on nanotopography than those cultured on Ti‐Machined. The analysis of the expression of calcium‐calmodulin‐dependent protein kinase II and β‐catenin demonstrated that Fzd6 disruption inhibited the osteoblast differentiation induced by Ti‐Nano by preventing the activation of Wnt/β‐catenin but not that of Wnt/Ca 2+ signaling, which is usually triggered by the receptor Fzd6. These findings elucidate the biological function of Fzd6 as a receptor that triggers Wnt/β‐catenin signaling and the cellular mechanisms modulated by nanotopography during osteoblast differentiation.