Silver nanoparticles promote osteogenic differentiation of human periodontal ligament fibroblasts by regulating the RhoA–TAZ axis

Abstract

Silver nanoparticles (AgNps) are well established antibacterial agents, which have been reported to promote osteogenesis of stem cells. Ras homolog gene family member A (RhoA) and Tafazzin (TAZ) have been recently shown to be involved in osteogenic differentiation. The present study aimed to evaluate the effects of AgNps on osteogenic differentiation of human periodontal ligament fibroblasts (HPDLFs), and investigate the underlying mechanisms of AgNps activity. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay was employed to determine the safe concentration of AgNps in HPDLFs. Using an alkaline phosphatase assay, Alizarin red S staining and detection of the expression of alkaline phosphatase (ALP), runt‐related transcription factor 2 (RUNX2), osteocalcin (OCN), osterix (OSX), and collagen‐I, we found that AgNps, at a concentration range of 25–100 μM, promoted osteogenic differentiation of HPDLFs in a dose‐dependent manner. We also found that 100 μM AgNps up‐regulated the active RhoA expression level. The results of ALP activity and expression of osteogenic markers showed that the effects of AgNps on osteogenic differentiation were abrogated by a RhoA pathway inhibitor, C3 reagent. Additionally, silencing of TAZ attenuated the AgNps‐induced osteogenic differentiation of HPDLFs, as shown by decreased ALP activity and down‐regulation of osteogenic markers. Interestingly, TAZ knockdown had a very small effect on the activity of RhoA, whereas C3 suppressed the expression of TAZ, indicating that TAZ was a downstream effector of RhoA. In conclusion, the present work demonstrated that AgNps promoted osteogenic differentiation of HPDLFs by activating the RhoA–TAZ axis.

miR‐140 inhibits osteogenic differentiation of human periodontal ligament fibroblasts through ras homolog gene family, member A ‐transcriptional co‐activator with PDZ‐binding motif pathway

“…Furthermore, RhoA‐TAZ signaling was recently found to be associated with hPDLFs osteodifferentiation. The latest study revealed that silver nanoparticles promoted osteodifferentiation of hPDLFs through regulating the RhoA‐TAZ signaling, 10 which was consistent with our discovery. We found that RhoA‐TAZ pathway promoted ALP activity, ARS activity and expression of COL1, RUNX2, ALP, and OCN, which was reduced by miR‐140 mimics, suggesting by inhibiting RhoA‐TAZ signaling pathway, miR‐140 suppressed the osteogenesis differentiation of hPDLFs.…”

“…Besides, we demonstrated that OE‐RhoA promoted ALP activity, ARS activity and expression of COL1, RUNX2, ALP, and OCN which was reduced by miR‐140 mimics, suggesting miR‐140 inhibited osteodifferentiation of hPDLFs by suppressing RhoA. RhoA‐TAZ pathway was reported to play functions in osteogenic differentiation in recent years 8–10 . Recent study demonstrated that icariin promoted proliferation and osteodifferentiation of rat adipose‐derived stem cells through stimulating the RhoA‐TAZ pathway 8 .…”

“…It was found that loss of kindlin‐2 inhibited RhoA activation and kindlin‐2 regulated the differentiation of mesenchymal stem cell by YAP1/TAZ regulation 9 . Besides, antibacterial agent sliver nanoparticles enhanced osteodifferentiation of hPDLFs via promoting the RhoA‐TAZ axis 10 . Therefore, we explored whether RhoA‐TAZ axis mediated the osteogenic differentiation of hPDLFs in our study.…”

“…Ras homolog gene family, member A (RhoA) is a member of the family of Rho GTPase and previous studies indicated that RhoA and focal adhesion kinase (FAK) regulate mechanical force‐subjected PDL fibroblasts by inducing extracellular regulated protein kinases (ERK)‐mediated osteopontin expression 7 . Furthermore, RhoA‐transcriptional co‐activator with PDZ (PSD‐95, Disc‐large and ZO‐1)‐binding motif (TAZ) signaling pathway was reported to play important role in osteogenic differentiation 8–10 . It was reported that icariin promoted proliferation and osteogenic differentiation of rat adipose‐derived stem cells by activating the RhoA‐TAZ signaling pathway 8 .…”

A Multifunctional Antibacterial and Osteogenic Nanomedicine: QAS-Modified Core-Shell Mesoporous Silica Containing Ag Nanoparticles

“…In the first 6 days, the QHMS and Ag@QHMS displayed a slightly positive influence on the proliferation of BMSCs. It is considered that the slowly released Si and Ag ions in solution may then affect the cytoskeleton through the ROCK-1 pathway mediated by β -integrin, which leads to the promotion of osteoblast division and differentiation [ 18 , 40 ]; however, the specific mechanism still needs to be further verified. After 7 days of coculture, the cell proliferation in all groups decreased, although the difference was not significant compared with the negative control group.…”