Osteogenically-induced exosomes stimulate osteogenesis of human adipose-derived stem cells

Mengru Zhu,Hongzhi Qin,Ting Wang,Shuang Tong,Yang Liu,Shu Guo,Mengying Cui,Qiang Sun,Hua Zhang

doi:10.1007/s10561-020-09867-8

Abstract

Exosomes exhibit great therapeutic potential in bone tissue engineering. The study aimed to investigate whether the exosomes derived from human adipose-derived stem cells (hADSCs-Exos) during different time-span of osteogenic differentiation could promote osteogenesis. The appropriate concentrations of hADSCs-Exos to enhance the proliferation, migration and osteogenesis of hADSCs-Exos were also examined. PKH67 labelled hADSCs-Exos was used to detect the internalization ability of hADSCs. The osteogenic differentiation abilities of hADSCs after treatment with hADSCs-Exos was evaluated by Alizarin red staining (ARS). The proliferation and migration of hADSCs was examined by cell counting kit-8 and wound healing assay, respectively. The expression of exosomal surface markers and osteoblast-related protein of hADSCs was assessed by Western blot. PKH67-labelled exosomes were internalized by hADSCs after 4 h incubation. ARS showed that the amount of mineralized nodules in Exo1−14d group was significantly higher than that in Exo15−28d group. hADSCs-Exos could promote the proliferation and migration capacity of hADSCs. Western blot analysis showed that after hADSCs-Exos treatment, ALP and RUNX2 were significantly enhanced. Specially, the Exo1−14d group of 15 μg/mL significantly upregulated the expression of RUNX2 than the other exosomes treated groups. Our findings suggest that exosomes secreted by hADSCs during osteogenic induction for 1–14 days could be efficiently internalized by hADSCs and could induce osteogenic differentiation of hADSCs. Moreover, administration of Exo1−14d at 15 μg/mL promoted the proliferation and migration of hADSCs. In conclusion, our research confirmed that comprised of hADSCs-Exos and hADSCs may provide a new therapeutic paradigm for bone tissue engineering.

Highlights

A large number of people have suffered from bone defects owing to trauma, infection osteonecrosis, congenital deformities, resection of tumors and other bone diseases (Chen et al 2010; Seong et al 2010)
Our findings suggest that exosomes secreted by human adipose-derived stem cells (hADSCs) during osteogenic induction for 1–14 days could be efficiently internalized by hADSCs and could induce osteogenic differentiation of hADSCs
PM: proliferation medium; osteogenic induction media (OM): osteogenic medium. ***p \ 0.001 compared with PM group, DDDp \ 0.001 compared with OM group, ###p \ 0.001 represents significant differences between compared groups. (Color figure online) self-renewal capability and multilineage differentiation potential of osteogenesis, chondrogenesis, adipogenesis and neurogenesis (Huo et al 2018; Majidinia et al 2018)

Summary

Introduction

A large number of people have suffered from bone defects owing to trauma, infection osteonecrosis, congenital deformities, resection of tumors and other bone diseases (Chen et al 2010; Seong et al 2010). Bone grafting is considered as the ‘‘gold standard’’ for treatment of bone defects, including autologous bone grafts, allogeneic bone grafts, and bone-graft substitutes (Dimitriou et al 2011). All these techniques have certain limitations, such as donor-site defect, poor bone quality and limited availability of grafting material (Du et al 2019; Lord et al 1988). The remarkable development of bone tissue engineering has brought the dawn to the therapy of bone defects (El-Rashidy et al 2017).

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