Distinct mechanisms of iron and zinc metal ions on osteo-immunomodulation of silicocarnotite bioceramics.

The immunomodulatory of implants have drawn more and more attention these years. However, the immunomodulatory of different elements on the same biomaterials have been rarely investigated. In this work, two widely used biosafety elements, iron and zinc added silicocarnotite (Ca5(PO4)2SiO4, CPS) were applied to explore the routine of elements on immune response. The immune reactions over time of Fe-CPS and Zn-CPS were explored at genetic level and protein level, and the effects of their immune microenvironment with different time points on osteogenesis were also investigated in depth. The results confirmed that both Fe-CPS and Zn-CPS had favorable ability to secret anti-inflammatory cytokines. The immune microenvironment of Fe-CPS and Zn-CPS also could accelerate osteogenesis and osteogenic differentiation in vitro and in vivo. In terms of mechanism, RNA-seq analysis and Western-blot experiment revealed that PI3K-Akt signaling pathway and JAK-STAT signaling pathways were activated of Fe-CPS to promote macrophage polarization from M1 to M2, and its immune microenvironment induced osteogenic differentiation through the activation of Hippo signaling pathway. In comparison, Zn-CPS inhibited polarization of M1 macrophage via the up-regulation of Rap1 signaling pathway and complement and coagulation cascade pathway, while its osteogenic differentiation related pathway of immune environment was NF-κB signaling pathway.

Osteoimmune reaction caused by a novel silicocarnotite bioceramic promoting osteogenesis through the MAPK pathway.

The host immune response to an implant is a key factor in determining the fate of bone grafts, which is thought to be a regulator of tissue regeneration. Figuring out the effects of the osteoimmune microenvironment on the osteogenesis of bone grafts can be a valuable strategy for their design and can further enhance the healing of bone defects. Our previous study demonstrated that the silicocarnotite (Ca5(PO4)2SiO4, CPS) bioceramic can significantly promote osteogenesis. The aim of this study is to investigate the immune reaction of CPS, the effects of the immune microenvironment on osteogenesis, and the related molecular mechanisms. Compared to hydroxyapatite (Ca10(PO4)6(OH)2, HA), the results showed that CPS could downregulate the pro-inflammatory phenotype and upregulate the anti-inflammatory phenotype, showing the lower levels of TNF-α and increased expression of IL-10. We further found that CPS could regulate the expression of NPPA, EDN1, and MMP9 in RAW 264.7 by RNA sequencing, which may be related to its superiority in osteogenesis. The osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) was subsequently studied in a macrophage-conditioned medium pretreated with CPS, and the medium caused a significant promotion of the osteogenic differentiation of rBMSCs, demonstrating that CPS can generate a favorable immune microenvironment to promote rBMSCs differentiation. In terms of mechanism, CPS in the macrophage-conditioned medium promoted osteogenic differentiation through the MAPK pathway, including ERK1/2, JNK and P38. Our study demonstrated that osteogenic differentiation was influenced by the immune microenvironment generated via the implant, and also presented an effective tool for studying the mechanisms of macrophage polarization as well as functions.

Targeted sequencing of NOTCH signaling pathway genes and association analysis of variants correlated with mandibular prognathism.

INTRODUCTION: The purpose of this study was to systematically identify variants in NOTCH signaling pathway genes that correlate with mandibular prognathism (MP) in the general Chinese population. METHODS: Targeted sequencing of NOTCH signaling pathway genes was conducted in 199 MP individuals and 197 class I malocclusion control individuals. The associations of common and rare variants with MP, cephalometric parameters, and continuous cephalometric phenotypes were analyzed by principal component (PC) analysis. The associations between rare variants and MP were tested for each gene. RESULTS: Six SNPs, including rs415929, rs520688, and rs423023 in an exonic region of NOTCH4; rs1044006 in an exonic region of NOTCH3; rs1051415 in an exonic region of JAG1; and rs75236173 in the 3'-untranslated region (3'-UTR) of NUMB were associated with MP (P < 0.05). One common variant, rs1051415, in an exonic region of JAG1 was significantly related to PC1 (P  = 3.608 × 10- 4), which explained 24.3% of the overall phenotypic variation observed and corresponded to the sagittal mandibular position towards the maxilla, ranging from a posterior positioned mandible to an anterior positioned mandible. Additionally, 41 other variants were associated with PC1-5 (P  <  0.05). With respect to rare variant analysis, variants within the EP300, NCOR2, and PSEN2 gene showed an association with MP (t   < 0 .05). CONCLUSIONS: An association between NOTCH signaling pathway genes and MP has been identified.