Human fetal mesenchymal stem cell secretome enhances bone consolidation in distraction osteogenesis.
Distraction osteogenesis (DO) is one of the most dramatic reconstructive techniques for inducing bone regeneration, but it involves an undesirably long period for bone consolidation. Developing innovative approaches to enhance bone consolidation is a burning need. Human fetal mesenchymal stem cells (hFMSCs) have been shown to express more primitive developmental genes than those of human adult mesenchymal stem cells (hAMSCs), which is a preferable source for cell therapy and tissue regeneration. In the present study, we investigated the immunogenicity of using the human mesenchymal stem cell (MSC) secretome on rat cells, the effects of secretome on osteogenic differentiation of rat bone marrow-derived MSCs (rBMSCs), and the potential application of hFMSC secretome in promoting bone consolidation in a rat DO model.



Secretome was collected from MSC culture and was used to treat rBMSCs. Following secretome treatment, cell proliferation, alkaline phosphatase staining, Alizarin Red S staining, and mRNA expression of osteogenic differentiation-related genes (including ALP, Runx2, OCN, OPN, and Osx) in the rBMSCs were checked, as well as mixed rat peripheral blood lymphocyte reaction. hFMSC secretome was injected locally into the regenerates from the end of lengthening every 3 days in the rat DO model, until termination. The regenerates were subject to weekly x-rays, micro-computed tomography (μCT) and mechanical testing examination. The bone quality was assessed by histology and immunohistochemistry examinations.



Compared to the secretome from rBMSCs and hAMSCs, hFMSC secretome had the best osteogenic induction ability and low immunogenicity. hFMSC secretome with different doses showed no effect on cell viability. hFMSC secretome at the dose of 100 μg/μl could significantly increase the expression of alkaline phosphatase and all the osteogenic marker genes, as well as the amount of calcium deposits in the rBMSCs. Finally, the local application of hFMSC secretome in distraction regenerates in a rat DO model significantly improved bone consolidation according to the results of μCT, mechanical test, and histological and immunohistochemistry analysis.



The current study demonstrated that hFMSC secretome promotes osteogenesis of rBMSCs and bone consolidation during DO. hFMSC secretome may be a new therapeutic strategy to enhance bone consolidation in patients undergoing DO treatment.
Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China.|Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.
Jia
J
Xu
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.
Bin
B
Wang
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.
Yuxin
Y
Sun
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.
Tianyi
T
Wu
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.
Yang
Y
Liu
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.|The CUHK-ACC Space Medicine Centre, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, People's Republic of China.
Jinfang
J
Zhang
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China.
Wayne Yukwai
WY
Lee
Department of Orthopaedics and Traumatology, Bao-An People's Hospital, Shenzhen, People's Republic of China.
Xiaohua
X
Pan
Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China. ymchai@sjtu.edu.cn.
Yimin
Y
Chai
Department of Orthopaedics & Traumatology, Stem Cells and Regeneration Laboratory, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR, People's Republic of China. gangli@cuhk.edu.hk.|The CUHK-ACC Space Medicine Centre, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, People's Republic of China. gangli@cuhk.edu.hk.|Department of Orthopaedics and Traumatology, Bao-An People's Hospital, Shenzhen, People's Republic of China. gangli@cuhk.edu.hk.
Gang
G
Li
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism* / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D064987:Cell- and Tissue-Based Therapy / Q000379:methods; D002478:Cells, Cultured; D053686:Fetal Stem Cells / Q000378:metabolism* / Q000502:physiology; D005333:Fetus / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism* / Q000502:physiology; D019857:Osteogenesis, Distraction / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley
D000469:Alkaline Phosphatase
Bone consolidation; Distraction osteogenesis; Osteogenesis; Secretome; hFMSCs