Currently, treatment of large bone defect is based on autologous or allogenic bone grafts that still have limitations and issues. Bone tissue engineering with cell transplantation could provide an alternative way to stimulate bone repair. In the past few years, numerous studies have been conducted to investigate the osteogenic potential of human amniotic fluid-derived stem cells (hAFSCs) in the repair of bone defects. The absence of ethic controversy and risk of teratoma formation makes hAFSCs particularly interesting in the field of regenerative medicine. Despite this, there is ample discussion in literature about the effects and role of hAFSCs in bone tissue repair, since their fate in vivo in the repair of large bone defects is still unknown at present [1, 2]. The aim of this study was to investigate the role of pre-differentiated hAFSCs in the repair of critical-size bone defects in calvaria mouse model. For this purpose, we transduced hAFSCs with Ub cherry lentivirus and used a recipient transgenic mouse model carrying GFP fluorescent reporter. Thanks to these systems, we were able to follow the fate of hAFSCs transplanted in vivo into Healos® (collagen-hydroxyapatite scaffold) construct and to distinguish donor and host cells at the implant site. Our results showed that viral transduction of hAFSCs produce a population permanently labeled with cherry red fluorescent protein useful to track the fate of these cells in vivo directly at the site of transplantation. Flow cytometry analysis demonstrated a lower expression of mesenchymal markers on the surface of pre-differentiated hAFSCs compared to undifferentiated cells, suggesting a partial commitment to osteogenic lineage, useful for in vivo transplantation studies. Moreover, we observed that hAFSCs are able to attract mouse bone marrow stromal cells (mBMSCs) in vitro, suggesting a possible chemotactic role of their releasing soluble factors. In accordance with previous results reported by other authors, we showed that cherry red fluorescent hAFSCs, once transplanted in vivo, are not present at the implant site after 3 and 6 weeks. Instead, the presence of a greater number of GFP positive cells in the scaffold at the same time-intervals, compared with implants using Healos® and mBMSCs, indicates that hAFSCs are able to recruit host cells during the repair process. These observations help clarify the role of hAFSCs in bone tissue repair. Further studies will be needed to determine whether the host cells that are recruited are able to form new bone.
Chemotactic properties of human amniotic fluid-derived stem cells in mouse calvaria defect model
Centurione MA;
2018
Abstract
Currently, treatment of large bone defect is based on autologous or allogenic bone grafts that still have limitations and issues. Bone tissue engineering with cell transplantation could provide an alternative way to stimulate bone repair. In the past few years, numerous studies have been conducted to investigate the osteogenic potential of human amniotic fluid-derived stem cells (hAFSCs) in the repair of bone defects. The absence of ethic controversy and risk of teratoma formation makes hAFSCs particularly interesting in the field of regenerative medicine. Despite this, there is ample discussion in literature about the effects and role of hAFSCs in bone tissue repair, since their fate in vivo in the repair of large bone defects is still unknown at present [1, 2]. The aim of this study was to investigate the role of pre-differentiated hAFSCs in the repair of critical-size bone defects in calvaria mouse model. For this purpose, we transduced hAFSCs with Ub cherry lentivirus and used a recipient transgenic mouse model carrying GFP fluorescent reporter. Thanks to these systems, we were able to follow the fate of hAFSCs transplanted in vivo into Healos® (collagen-hydroxyapatite scaffold) construct and to distinguish donor and host cells at the implant site. Our results showed that viral transduction of hAFSCs produce a population permanently labeled with cherry red fluorescent protein useful to track the fate of these cells in vivo directly at the site of transplantation. Flow cytometry analysis demonstrated a lower expression of mesenchymal markers on the surface of pre-differentiated hAFSCs compared to undifferentiated cells, suggesting a partial commitment to osteogenic lineage, useful for in vivo transplantation studies. Moreover, we observed that hAFSCs are able to attract mouse bone marrow stromal cells (mBMSCs) in vitro, suggesting a possible chemotactic role of their releasing soluble factors. In accordance with previous results reported by other authors, we showed that cherry red fluorescent hAFSCs, once transplanted in vivo, are not present at the implant site after 3 and 6 weeks. Instead, the presence of a greater number of GFP positive cells in the scaffold at the same time-intervals, compared with implants using Healos® and mBMSCs, indicates that hAFSCs are able to recruit host cells during the repair process. These observations help clarify the role of hAFSCs in bone tissue repair. Further studies will be needed to determine whether the host cells that are recruited are able to form new bone.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
