Abstract : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
The present study was to determine the effect of local anti-RANKL antibody administration in the presence or absence of microRNA-146a on ligature-induced peri-implant bone resorption, and the potential role of TLR2/4 signaling in such effect.
Titanium implants were placed in the left maxilla alveolar bone 6 weeks after extraction of first and second molars in C57/BL6 wild-type (WT) and TLR2−/− TLR4−/− (TLR2/4 KO) mice. Silk ligatures were tied around the implants 4 weeks after implantation. Anti-RANKL antibody (500 μg/mL) with or without microRNA 146a (miR-146a) (100 nM) was injected into palatal gingiva around implant on days 3, 6, and 9 during 2 weeks of ligation period. Bone resorption around the implants was assessed by 2D imaging using area measurement and 3D imaging using micro-computed tomography (μCT). Real-time quantitative PCR (RT-qPCR) was used to determine the peri-implant gingival mRNA expression levels of pro-inflammatory cytokines (TNF-α) and osteoclastogenesis-related cytokines (RANKL). In both WT and TLR2/4 KO mice, the bone resorption around implants was significantly increased in the ligation only group when compared to the non-ligation group, but TLR2/4 KO mice showed significantly less bone loss compared to WT mice after ligation. As expected, gingival injection of anti-RANKL antibody significantly reduced bone loss compared with the ligation only group in both WT and TLR2/4 KO mice. Moreover, injection of miR-146a in addition to anti-RANKL antibody significantly enhanced the inhibition of bone loss in WT mice but not in TLR2/4 KO mice. Gingival mRNA expressions of RANKL were significantly reduced by anti-RANKL antibody treatment in both WT and TLR2/4 KO mice but were not affected by the additional miR-146a treatment. Gingival mRNA expression of TNF-α was significantly reduced by miR-146a treatment in WT mice but not in TLR2/4 KO mice. The number of gingival inflammatory cell infiltration and peri-implant TRAP-positive cell formation was significantly reduced by the additional miR-146a treatment in WT mice but not in TLR2/4 KO mice.
Serial posts:
- Abstract : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- Abstract : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- Background : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- Background : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- Methods : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- Methods : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- Methods : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [3]
- Results : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- Results : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- Discussion : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- Discussion : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- Conclusions : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Availability of data and materials : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Abbreviations : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- References : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- References : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- References : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [3]
- References : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [4]
- Acknowledgements : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Funding : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Author information : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [1]
- Author information : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling [2]
- Ethics declarations : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Additional information : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Supplementary information : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Rights and permissions : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- About this article : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling
- Table 1 Success rate (SR) of osseointegrated implants 4 weeks after implant placement : RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through
- Fig. 1. Mouse model of ligature-induced experimental peri-implantitis. (a) Tooth extraction: left maxillary first and second molars extracted at 4 weeks old and the tooth extraction socket healed well with smooth gingiva surface after 6 weeks post-extraction. Implant placement: implant was put in alveolar bone without flap elevation. Ligature placement: at 4 weeks post-implant, 7-0 ligatures were applied under the fixture head. Gingival injection: injections for animals were administered three times on days 3, 6, and 9 during 14 days ligation period. Sample collection: 14 days post-ligation, the gingival tissues and the skulls were collected. (b) Images depicting processing steps of the experimental design (scale bar, 500 μm) : RANKL blockade alleviates peri-implant
- Fig. 2. Anti-RANKL and anti-RANKL+miR-146a treatments decreased ligature-induced bone resorption with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. Buccal side images of the defleshed skulls were taken of the control (non-ligation) group, ligation (non-treatment) group, ligation with anti-RANKL antibody (ligation+AR) treatment group, and ligation with anti-RANKL antibody + miR-146a (ligation+A+MiR) treatment group in WT mice and TLR2/4 KO mice (a) (scale bar, 500 μm). The bone resorption area based on these images was measured and analyzed for WT mice (b) and TLR2/4 KO mice (c) (mean ± SD, n = 6, *p < 0.05, **p < 0.01, SEM, standard error of difference between two means). Three dimension (3D) images from μCT were collected and analyzed for WT mice (d) and TLR4 KO mice (e) (mean ± SD, n = 6, *p < 0.05, **p < 0.01) : RANKL blockade alleviates peri-implant
- Fig. 3. Anti-RANKL and anti-RANKL+miR-146a treatments decreased TRAP-positive cell quantities with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. TRAP-positive cells (red color) with 3 or more nuclei were considered osteoclasts and were shown in the control group, ligation group, ligation with anti-RANKL antibody treatment group, and ligation with anti-RANKL antibody + miR-146a treatment group in WT mice and TLR2/4 KO mice (a) (Im, implant; Av, alveolar bone; scale bar, 100 μm). The quantities of TRAP-positive cells were analyzed in each group of WT mice (b) and TLR2/4 KO mice (c) (mean ± SD, n = 6, **p < 0.01) : RANKL blockade alleviates peri-implant
- Fig. 4. Anti-RANKL and anti-RANKL+miR-146a treatments decreased the inflammatory cell infiltration of the implant gingival tissues with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. HE staining of the gingival tissue around implants were performed in the control group, ligation group, ligation with anti-RANKL antibody treatment group, and ligation with anti-RANKL antibody + miR-146a treatment group in WT mice and TLR2/4 KO mice (a) (scale bar, 100 μm). Inflammatory cell numbers were measured and analyzed in each group of WT mice (b) and TLR2/4 KO mice (c) (mean ± SD, n = 6, **p < 0.01) : RANKL blockade alleviates peri-implant
- Fig. 5. Anti-RANKL and anti-RANKL+miR-146a treatments decreased gingival mRNA expression of TNF-α and RANKL with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. Gingival tissues around ligatured implants and non-ligation implants were excised and processed for RT-qPCR analysis to determine mRNA level of TNF-α of WT mice (a) and TLR2/4 KO mice (b) (mean ± SD, n = 6, *p < 0.05, **p < 0.01) and mRNA level of RANKL of WT mice (c) and TLR2/4 KO mice (d) (mean ± SD, n = 6, *p < 0.05, **p < 0.01). : RANKL blockade alleviates peri-implant