Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation.
Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibited a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering.
Department of Pediatric Surgery, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China; Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038, China. Electronic address: dingke@med.uestc.edu.cn.
Ke
K
Ding
Department of Pediatric Surgery, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China.
Wen-Ying
WY
Liu
Department of Pediatric Surgery, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China.
Qiang
Q
Zeng
Department of Pediatric Surgery, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China.
Fang
F
Hou
Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038, China. Electronic address: xjzspine@163.com.
Jian-Zhong
JZ
Xu
Department of Clinical Hematology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China. Electronic address: zyang1999@163.com.
Zhong
Z
Yang
D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D007124:Immunoenzyme Techniques; D051957:MSX1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D008822:Mice, Transgenic; D010012:Osteogenesis / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation; D001616:beta-Galactosidase
D051957:MSX1 Transcription Factor; D012333:RNA, Messenger; D001616:beta-Galactosidase
Bone tissue engineering; Msx1; Multipotential; Muscle satellite cells; Osteogenic differentiation