PF127 Hydrogel-Based Delivery of Exosomal CTNNB1 from Mesenchymal Stem Cells Induces Osteogenic Differentiation during the Repair of Alveolar Bone Defects

Longlong He; Qin Zhou; Hengwei Zhang; Ningbo Zhao; Lifan Liao

doi:10.3390/nano13061083

PF127 Hydrogel-Based Delivery of Exosomal CTNNB1 from Mesenchymal Stem Cells Induces Osteogenic Differentiation during the Repair of Alveolar Bone Defects

Nanomaterials (Basel). 2023 Mar 16;13(6):1083. doi: 10.3390/nano13061083.

Authors

Longlong He^{1

2}, Qin Zhou^{1

2}, Hengwei Zhang¹, Ningbo Zhao^{1

2}, Lifan Liao^{1

2}

Affiliations

¹ Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.
² Department of Implant Dentistry, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.

Abstract

Pluronic F127 (PF127) hydrogel has been highlighted as a promising biomaterial for bone regeneration, but the specific molecular mechanism remains largely unknown. Herein, we addressed this issue in a temperature-responsive PF127 hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (Exos) (PF127 hydrogel@BMSC-Exos) during alveolar bone regeneration. Genes enriched in BMSC-Exos and upregulated during the osteogenic differentiation of BMSCs and their downstream regulators were predicted by bioinformatics analyses. CTNNB1 was predicted to be the key gene of BMSC-Exos in the osteogenic differentiation of BMSCs, during which miR-146a-5p, IRAK1, and TRAF6 might be the downstream factors. Osteogenic differentiation was induced in BMSCs, in which ectopic expression of CTNNB1 was introduced and from which Exos were isolated. The CTNNB1-enriched PF127 hydrogel@BMSC-Exos were constructed and implanted into in vivo rat models of alveolar bone defects. In vitro experiment data showed that PF127 hydrogel@BMSC-Exos efficiently delivered CTNNB1 to BMSCs, which subsequently promoted the osteogenic differentiation of BMSCs, as evidenced by enhanced ALP staining intensity and activity, extracellular matrix mineralization (p < 0.05), and upregulated RUNX2 and OCN expression (p < 0.05). Functional experiments were conducted to examine the relationships among CTNNB1, microRNA (miR)-146a-5p, and IRAK1 and TRAF6. Mechanistically, CTNNB1 activated miR-146a-5p transcription to downregulate IRAK1 and TRAF6 (p < 0.05), which induced the osteogenic differentiation of BMSCs and facilitated alveolar bone regeneration in rats (increased new bone formation and elevated BV/TV ratio and BMD, all with p < 0.05). Collectively, CTNNB1-containing PF127 hydrogel@BMSC-Exos promote the osteogenic differentiation of BMSCs by regulating the miR-146a-5p/IRAK1/TRAF6 axis, thus inducing the repair of alveolar bone defects in rats.

Keywords: CTNNB1; IRAK1; TRAF6; alveolar bone defect; bone marrow mesenchymal stem cells; exosomes; microRNA-146a-5p; osteogenic differentiation; temperature-responsive hydrogel.

Grants and funding

This work was supported by Science and Technology Bureau of Xi’an of China-Xi’an Innovation Capability Strong Foundation Program-Medical Research Project (21YXYJ0124), Medical research project of Xi’an Science and Technology Bureau of China-General Project (2022JH-YBYJ-0354) and National Natural Science Foundation of China (22078209).