Resolvin D1 improves allograft osteointegration and directly enhances osteoblasts differentiation

Abstract

IntroductionAllografts are the most common bone grafts for repairing osseous defects. However, their use is associated with an increased risk for infections, donor disease transmission and osteointegration deficiency. Resolvin D1 (RvD1) is an endogenous lipid with a scientifically proven pivotal role in inflammation resolution and osteoclastogenesis inhibition. Yet, its biological relevance as a potential bone regenerative drug has been scarcely studied. Here, we aim to investigate the RvD1 effect on allograft osteointegration in the alveolar bone regeneration (ABR) murine model.MethodsABR model consisted of osseous defects that were generated by the extraction of the maxillary first molar in C57BL/6 mice. The sockets were filled with allograft and analyzed via RNA sequencing. Then they were locally injected with either RvD1 or saline via single or repeated administrations. The mice were sacrificed 2W after the procedure, and regenerated sites were analyzed using µCT and histology. First, MC3T3-E1 preosteoblasts were plated with IL-17 pro-inflammatory medium, and RANKL/OPG ratio was measured. Secondly, the MC3T3-E1 were cultured w/o RvD1, for 3W. Osteoblasts’ markers were evaluated in different days, using qRT-PCR and Alizarin Red staining for calcified matrix.ResultsIn vivo, neither allograft alone nor single RvD1 administration promote bone regeneration in comparison to the control of spontaneous healing and even triggered an elevation in NR1D1 and IL1RL1 expression, markers associated with inflammation and inhibition of bone cell differentiation. However, repeated RvD1 treatment increased bone content by 135.92% ± 45.98% compared to its specific control, repeated sham, and by 39.12% ± 26.3% when compared to the spontaneous healing control group (n=7/group). Histologically, repeated RvD1 reduced the number of TRAP-positive cells, and enhanced allograft osteointegration with new bone formation. In vitro, RvD1 rescued OPG expression and decreased RANKL/OPG ratio in IL-17 pro-inflammatory conditions. Furthermore, RvD1 increased the expression of RUNX2, OSX, BSP and OC/BGLAP2 and the mineralized extracellular matrix during MC3T3-E1 osteoblasts differentiation.ConclusionsRepeated administrations of RvD1 promote bone regeneration via a dual mechanism: directly, via enhancement of osteoblasts’ differentiation and indirectly, through reduction of osteoclastogenesis and RANKL/OPG ratio. This suggests that RvD1 may be a potential therapeutic bioagent for osseous regeneration following allograft implantation.

Interleukin‐17 alleviates erastin‐induced alveolar bone loss by suppressing ferroptosis via interaction between NRF2 and p‐STAT3

“…As both IL‐17 and ferroptosis are closely related to bone repair and destruction (Dar et al, 2023; Pinto et al, 2023; Wang et al, 2023), we used erastin to aggravate ferroptosis and investigate the role of IL‐17 + erastin in experimental periodontitis mice. IHC staining was carried out to investigate the expression of IL‐17RA and its cellular localization in periodontal tissues.…”

“…Our results also indicated that the levels of ferroptotic molecules, NRF2, GPX4 and SLC7A11, were lower in the experimental tissues than in the normal periodontal tissues (Figure1f-h). The results suggested that osteoblast ferroptosis may be associated with periodontitis.3.2 | Influence of IL-17 on erastin-induced alveolar bone resorption in the experimental periodontitis modelAs both IL-17 and ferroptosis are closely related to bone repair and destruction(Dar et al, 2023;Pinto et al, 2023;Wang et al, 2023), we used erastin to aggravate ferroptosis and investigate the role of IL-17 + erastin in experimental periodontitis mice. IHC staining was carried out to investigate the expression of IL-17RA and its cellular localization in periodontal tissues.…”

The impact of Resolvin E1 on bone regeneration in critical‐sized calvarial defects of rat model—A gene expression and micro‐CT analysis

“…In rat calvarial defects, a recent work by Jiang et al 3 showed that RvD1 had enhanced bone regeneration and vascularization potential. Similarly, Pinto et al 9 have shown that RvD1 may be a viable therapeutic bioagent for osseous regeneration following the placement of allografts. In contrast, limited information is available on the bone regenerative potential of RvE1, and no prior studies have reported the effect of local application of RvE1 alone or with bone graft in enhancing bone regeneration.…”

“…Recently, Jiang et al3 demonstrated that a D variant of resolvins (RvD1) incorporated into nanopore scaffold and Pluronic F127 hydrogel group had enhanced bone formation and vascularization in rat calvarial defects compared to combined collagen 3D nanopore scaffold and pluronic F127 hydrogel group. Similarly, Pinto et al9 who also evaluated RvD1, demonstrated that RvD1 enhanced bone regeneration by increasing osteoblast differentiation and decreasing osteoclastogenesis and the RANKL/OPG ratio. The authors also showed that compared to a single administration of RvD1, repeated administration of RvD1 increased bone content by 135.92%.The outcome of this study showed the areas of NFB in all the study group.…”

“…4 Previous studies have reported better bone regeneration with adjunctive use of platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), bone morphogenic proteins (BMP), specialized pro-resolving mediators (SPMs) and platelet-derived growth factor (PDGF). 3,[5][6][7][8][9] An essential element of inflammatory responses is the resolution of inflammation. 10 Previously, it was understood that after the initiating stimulus had been eliminated, there would be a passive, progressive reduction in inflammatory processes.…”