TAZ promotes osteogenic differentiation of mesenchymal stem cells line C3H10T1/2, murine multi-lineage cells lines C2C12, and MEFs induced by BMP9

Multilayer Gelatin-Supported BMP-9 Coating Promotes Osteointegration and Neo-Bone Formation at the n-CDHA/PAA Composite Biomaterial-Bone Interface

BACKGROUND

The development of biomaterials capable of accelerating bone wound repair is a critical focus in bone tissue engineering. This study aims to evaluate the osteointegration and bone regeneration potential of a novel multilayer gelatin-supported Bone Morphogenetic Protein 9 (BMP-9) coated nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA) composite biomaterials, focusing on the material-bone interface, and putting forward a new direction for the research on the interface between the coating material and bone.

METHODS

The BMP-9 recombinant adenovirus (Adenovirus (Ad)-BMP-9/Bone Marrow Mesenchymal Stem Cells (BMSc)) was produced by transfecting BMSc and supported using gelatin (Ad-BMP-9/BMSc/Gelatin (GT). Multilayer Ad-BMP-9/BMSc/GT coated nano-calcium deficient hydroxyapatite/polyamino acid (n-CDHA/PAA) composite biomaterials were then prepared and co-cultured with MG63 cells for 10 days, with biocompatibility assessed through microscopy, Cell Counting Kit-8 (CCK-8), and alkaline phosphatase (ALP) assays. Subsequently, multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws were fabricated, and the adhesion of the coating to the substrate was observed using scanning electron microscopy (SEM). In vivo studies were conducted using a New Zealand White rabbit intercondylar femoral fracture model. The experimental group was fixed with screws featuring multilayer Ad-BMP-9/BMSc/GT coatings, while the control groups used medical metal screws and n-CDHA/PAA composite biomaterial screws. Fracture healing was monitored at 1, 4, 12, and 24 weeks, respectively, using X-ray observation, Micro-CT imaging, and SEM. Integration at the material-bone interface and the condition of neo-tissue were assessed through these imaging techniques.

RESULTS

The Ad-BMP-9/GT coating significantly enhanced MG63 cell adhesion, proliferation, and differentiation, while increasing BMP-9 expression in vitro. In vivo studies using a rabbit femoral fracture model confirmed the biocompatibility and osteointegration potential of the multilayer Ad-BMP-9/BMSc/GT coated n-CDHA/PAA composite biomaterial screws. Compared to control groups (medical metal screws and n-CDHA/PAA composite biomaterial screws), this material demonstrated faster fracture healing, stronger osteointegration, and facilitated new bone tissue formation with increased calcium deposition at the material-bone interface.

CONCLUSION

The multilayer GT-supported BMP-9 coated n-CDHA/PAA composite biomaterials have demonstrated favorable osteogenic cell interface performance, both in vitro and in vivo. This study provides a foundation for developing innovative bone repair materials, holding promise for significant advancements in clinical applications.

TAZ reverses the inhibitory effects of LPS on the osteogenic differentiation of human periodontal ligament stem cells through the NF-κB signaling pathway

BACKGROUND

Human periodontal ligament stem cells (hPDLSCs) are important candidate seed cells for periodontal tissue engineering, but the presence of lipopolysaccharide(LPS) in periodontal tissues inhibits the self-renewal and osteogenic differentiation of hPDLSCs. Our previous studies demonstrated that TAZ is a positive regulator of osteogenic differentiation of hPDLSCs, but whether TAZ can protect hPDLSCs from LPS is still unknown. The present study aimed to explore the regulatory effect of TAZ on the osteogenic differentiation of hPDLSCs in an LPS-induced inflammatory model, and to preliminarily reveal the molecular mechanisms related to the NF-κB signaling pathway.

METHODS

LPS was added to the culture medium of hPDLSCs. The influence of LPS on hPDLSC proliferation was analyzed by CCK-8 assays. The effects of LPS on hPDLSC osteogenic differentiation were detected by Alizarin Red staining, ALP staining, Western Blot and qRT-PCR analysis of osteogenesis-related genes. The effects of LPS on the osteogenic differentiation of hPDLSCs with TAZ overexpressed or knocked down via lentivirus were analyzed. NF-κB signaling in hPDLSCs was analyzed by Western Blot and immunofluorescence.

RESULTS

LPS inhibited the osteogenic differentiation of hPDLSCs, inhibited TAZ expression, and activated the NF-κB signaling pathway. Overexpressing TAZ in hPDLSCs partly reversed the negative effects of LPS on osteogenic differentiation and inhibited the activation of the NF-κB pathway by LPS. TAZ knockdown enhanced the inhibitory effects of LPS on osteogenesis.

CONCLUSION

Overexpressing TAZ could partly reverse the inhibitory effects of LPS on the osteogenic differentiation of hPDLSCs, possibly through inhibiting the NF-κB signaling pathway. TAZ is a potential target for improving hPDLSC-based periodontal tissue regeneration in inflammatory environments.

EID3 inhibits the osteogenic differentiation of periodontal ligament stem cells and mediates the signal transduction of TAZ-EID3-AKT/MTOR/ERK

Exploring the molecular mechanisms of cell behaviors is beneficial for promoting periodontal ligament stem cell (PDLSC)-mediated tissue regeneration. This study intends to explore the regulatory effects of EID3 on cell proliferation, apoptosis, and osteogenic differentiation and to preliminarily explore the regulatory mechanism of EID3. Here, EID3 was overexpressed or knocked down in PDLSCs by recombinant lentivirus. Then, cell proliferation activity was analyzed by colony-forming assay, EdU assay, and cell cycle assay. Cell apoptosis was detected by flow cytometry. The osteo-differentiation potential was analyzed using ALP activity assay, ALP staining, alizarin red staining, and mRNA and protein assay of osteo-differentiation related genes. The results showed that when EID3 was knocked down, the proliferation activity and osteogenic differentiation potential of PDLSCs decreased, while they increased when EID3 was overexpressed. The cell apoptosis rate decreased in PDLSCs with EID3 knockdown but increased in PDLSCs with EID3 overexpression. Moreover, EID3 inhibited the transduction of the AKT/MTOR and ERK signaling pathway. In addition, TAZ negatively regulated the expression of EID3, and the overexpression of EID3 partially reversed the promotive effects of TAZ on the osteogenic differentiation of PDLSCs. Taken together, EID3 inhibits the proliferation and osteogenic differentiation while promoting the apoptosis of PDLSCs. EID3 inhibits the transduction of the AKT/MTOR and ERK signaling pathways and mediates the regulatory effect of TAZ on PDLSC osteogenic differentiation.