miR-21-5p Enriched Exosomes from Human Embryonic Stem Cells Promote Osteogenesis via YAP1 Modulation

Xinqia Huang,1,* Ziquan Zhao,1,* Weiqiang Zhan,1 Mingzhu Deng,1 Xuyang Wu,1 Zhoutao Chen,1 Jiahao Xie,2 Wei Ye,3 Mingyan Zhao,1,4 Jiaqi Chu3,4 1Orthopaedic Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, 524001, People’s Republic of China; 2Department of Dermatology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, 524001, People’s Republic of China; 3Department of Obstetrics and Gynecology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, 524001, People’s Republic of China; 4Stem Cell Research and Cellular Therapy Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, 524001, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jiaqi Chu; Mingyan Zhao, Affiliated Hospital of Guangdong Medical University, No. 57 Renmin Avenue South Road, Zhanjiang, Guangdong, 524001, People’s Republic of China, Email [email protected]; [email protected]: To investigate the osteogenic potential of human embryonic stem cell-derived exosomes (hESC-Exos) and their effects on the differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).Methods: hESC-Exos were isolated and characterized using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. hUCMSCs were cultured with hESC-Exos to assess osteogenic differentiation through alizarin red staining, quantitative PCR (qPCR), and Western blotting. miRNA profiling of hESC-Exos was performed using miRNA microarray analysis. In vivo bone regeneration was evaluated using an ovariectomized rat model with bone defects treated with exosome-loaded scaffolds.Results: hESC-Exos significantly promoted the osteogenic differentiation of hUCMSCs, as evidenced by increased alizarin red staining and the upregulation of osteogenesis-related genes and proteins (ALP, RUNX2, OCN). miRNA analysis revealed that miR-21-5p is a key regulator that targets YAP1 and activates the Wnt/β-catenin signaling pathway. In vivo, hESC-Exos enhanced bone repair in ovariectomized rats, as demonstrated by increased bone mineral density and improved bone microarchitecture compared to those in controls.Conclusion: hESC-Exos exhibit significant osteogenic potential by promoting the differentiation of hUCMSCs and enhancing bone regeneration in vivo. This study revealed that the miR-21-5p-YAP1/β-catenin axis is a critical pathway, suggesting that the use of hESC-Exos is a promising therapeutic strategy for bone regeneration and repair. Keywords: human embryonic stem cells, exosomes, osteogenic differentiation, bone regeneration, miR-21-5p, YAP1