Multi-Walled Carbon Nanotubes Promote Cementoblast Differentiation and Mineralization through the TGF-β/Smad Signaling Pathway

Abstract

Excretion of cementum by cementoblasts on the root surface is a process indispensable for the formation of a functional periodontal ligament. This study investigated whether carboxyl group-functionalized multi-walled carbon nanotubes (MWCNT-COOH) could enhance differentiation and mineralization of mammalian cementoblasts (OCCM-30) and the possible signaling pathway involved in this process. Cementoblasts were incubated with various doses of MWCNT-COOH suspension. Cell viability was detected, and a scanning electron microscopy (SEM) observed both the nanomaterials and the growth of cells cultured with the materials. Alizarin red staining was used to investigate the formation of calcium deposits. Real-time PCR and western blot were used to detect cementoblast differentiation and the underlying mechanisms through the expression of the osteogenic genes and the downstream effectors of the TGF-β/Smad signaling. The results showed that 5 µg/mL MWCNT-COOH had the most obvious effects on promoting differentiation without significant toxicity. Alp, Ocn, Bsp, Opn, Col1 and Runx2 gene expression was up-regulated. Smad2 and Smad3 mRNA was up-regulated, while Smad7 was first down-regulated on Day 3 and later up-regulated on Day 7. The elevated levels of phospho-Smad2/3 were also confirmed by western blot. In sum, the MWCNT-COOH promoted cementoblast differentiation and mineralization, at least partially, through interactions with the TGF-β/Smad pathway.

Vaspin antagonizes high fat-induced bone loss in rats and promotes osteoblastic differentiation in primary rat osteoblasts through Smad-Runx2 signaling pathway

“…Osteoblast differentiation is the key to bone formation, in which bone morphogenetic TGF-β/Smad signaling pathway is involved [40]. The previous studies revealed that Smad2/3 played an important role in the regulation of bone formation [41], and the expressions of Smad2/3 and p-Smad2/3 were elevated during cementoblast differentiation and mineralization [42]. Typically, the activation of the TGF-β/Smad signaling pathway mediates the phosphorylation of Smad2/3, which dimerizes with Smad4 and translocates to the nucleus, resulting in downstream gene transcription to direct cell differentiation [43].…”

Silver nanoparticles/chitosan oligosaccharide/poly(vinyl alcohol) nanofiber promotes wound healing by activating TGFβ1/Smad signaling pathway

“…They could create good conditions for the exchange of cell information and substance. 12 However, in the current literature, the effect of wound healing acceleration by electrospun nanofiber has only been examined at the pharmacodynamics stage. Therefore, the mechanisms of nanofiber-promoted wound healing remain unknown.…”

MicroRNA-409-3p promotes osteoblastic differentiation via activation of Wnt/β-catenin signaling pathway by targeting SCAI

“…At different times, the staining of mineralized nodules was remarkably reduced in the miR-409-3p analog + DKK-1 group when compared with the miR-409-3p analog group ( Figure 5 C, P <0.01). At last, the protein expression of the key markers for osteoblast differentiation-related genes, including ALP, OCN, OPN, RUNX2 [ 22 ], were also found to be markedly up-regulated in miR-409-3p analog group and down-regulated after DKK-1 treatment ( Figure 5 D, P <0.05). Overall, inhibition of Wnt signaling by DKK-1 treatment blocked miR-409-3p induced enhancement of osteoblastic differentiation of MSCs.…”

“…5C, p < 0.01). At last, the protein expression of the key markers for osteoblast differentiation-related genes, including ALP, OCN, OPN, RUNX2 [22], were also found to be markedly up-regulated in miR-409-3p analog group and down-regulation after DKK-1 treatment.…”