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The fate of systemically administrated allogeneic mesenchymal stem cells in mouse femoral fracture healing.

Huang S, Xu L, Sun Y, Zhang Y, Li G - Stem Cell Res Ther (2015)

Bottom Line: The fate and whereabouts of the allogenic mesenchymal stem cells (MSCs) following their transplantation are not well understood.Bone mineral density, bone volume/tissue volume, ultimate load, and E-modulus in the MSC injection groups were significantly higher than those in the PBS group.These findings provide useful information for the use of allogenic MSCs for cell therapy applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics & Traumatology, Faculty of Medicine, Room 904, 9/F, Li Ka Shing Institute of Health Institute, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong, SAR, PR China. huangshuo82@gmail.com.

ABSTRACT

Introduction: The fate and whereabouts of the allogenic mesenchymal stem cells (MSCs) following their transplantation are not well understood. The present study investigated the fate of systemically administrated allogeneic MSCs in mouse fracture healing by using in vivo imaging and immunohistochemistry methods.

Methods: Open femoral fracture with internal fixation was established in 30 FVB mice, which were assigned to three groups receiving phosphate-buffered saline (PBS) injection, MSC systemic injection, or MSC local injection. Luc-MSCs (5 × 10(5)) isolated from the luciferase transgenic mice with FVB background were injected at 4 days after fracture. All animals were terminated at 5 weeks after fracture; examinations included bioluminescence-based in vivo imaging, micro-computer tomography, mechanical testing, histology, immunohistochemistry, and double immunofluorescence staining.

Results: The bioluminescence signals of the Luc-MSCs at the fracture site could be detected for 12-14 days following their injection in the Luc-MSC local injection group, whereas in the Luc-MSC systemic injection group, Luc-MSCs were initially trapped in lungs for about 8-9 days and then gradually redistributed to the fracture site. Bone mineral density, bone volume/tissue volume, ultimate load, and E-modulus in the MSC injection groups were significantly higher than those in the PBS group. Double immunostaining demonstrated that the MSC local injection group had more Luc-positive cells, and there was a higher apoptotic rate at the fracture site than the MSC systemic injection group. Both Luciferase-positive MSCs and osteoblasts were present in the callus in the MSC injection groups at 5 weeks after fracture, suggesting that some of allogenic Luc-MSCs contributed to the new bone formation. Only less than 3 % of injected Luc-MSCs remained at the fracture site in the MSC injection groups at 5 weeks following the fracture, and the rest of the injected Luc-MSCs disappeared.

Conclusions: Our data showed that both systemic and local injection of allogeneic MSCs promoted fracture healing through enhancing biomechanical properties, bone content, and enlarged callus sizes. Immunohistochemistry confirmed that the injected MSCs are still present in the fracture site and can differentiate into osteoblasts to participate in fracture healing even at 5 weeks following the fracture. These findings provide useful information for the use of allogenic MSCs for cell therapy applications.

No MeSH data available.


Related in: MedlinePlus

Illustration of apoptotic cells at the fracture site. A mass of apoptotic cells (brown cells) was observed around the fracture ends within the callus in the Luc-MSC systemic injection group (a), the local injection group (b), and the PBS control group (c) at 5 weeks following the fracture, but none was observed in the negative control (the normal femur) (d). e-h High-resolution images were, respectively, enlarged from the red outlined areas in a–d. Both living Luc-positive cells (light green cells within red circles) and apoptotic Luc-positive cells (dark green cells within white circles) were found in the MSC systemic injection group (e) and the MSC local injection group (f) at 5 weeks following the fracture, but no Luc-positive cells were found in the PBS control group (g) and the negative control (h). Luc-MSC Luciferase labeled mesenchymal stem cell, MSC mesenchymal stem cell, PBS phosphate-buffered saline
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Fig5: Illustration of apoptotic cells at the fracture site. A mass of apoptotic cells (brown cells) was observed around the fracture ends within the callus in the Luc-MSC systemic injection group (a), the local injection group (b), and the PBS control group (c) at 5 weeks following the fracture, but none was observed in the negative control (the normal femur) (d). e-h High-resolution images were, respectively, enlarged from the red outlined areas in a–d. Both living Luc-positive cells (light green cells within red circles) and apoptotic Luc-positive cells (dark green cells within white circles) were found in the MSC systemic injection group (e) and the MSC local injection group (f) at 5 weeks following the fracture, but no Luc-positive cells were found in the PBS control group (g) and the negative control (h). Luc-MSC Luciferase labeled mesenchymal stem cell, MSC mesenchymal stem cell, PBS phosphate-buffered saline

Mentions: To examine the apoptosis level of injected Luc-MSCs, peroxidase staining and immunofluorescence staining were carried out on the same section. A mass of apoptotic cells (brown cells) was observed around the fracture sites within the callus in the Luc-MSC systemic injection group (Fig. 5a), the local injection group (Fig. 5b), and the PBS control group (Fig. 5c) at 5 weeks following the fracture, but none was observed in the negative control (the normal femur) (Fig. 5d).Fig. 5


The fate of systemically administrated allogeneic mesenchymal stem cells in mouse femoral fracture healing.

Huang S, Xu L, Sun Y, Zhang Y, Li G - Stem Cell Res Ther (2015)

Illustration of apoptotic cells at the fracture site. A mass of apoptotic cells (brown cells) was observed around the fracture ends within the callus in the Luc-MSC systemic injection group (a), the local injection group (b), and the PBS control group (c) at 5 weeks following the fracture, but none was observed in the negative control (the normal femur) (d). e-h High-resolution images were, respectively, enlarged from the red outlined areas in a–d. Both living Luc-positive cells (light green cells within red circles) and apoptotic Luc-positive cells (dark green cells within white circles) were found in the MSC systemic injection group (e) and the MSC local injection group (f) at 5 weeks following the fracture, but no Luc-positive cells were found in the PBS control group (g) and the negative control (h). Luc-MSC Luciferase labeled mesenchymal stem cell, MSC mesenchymal stem cell, PBS phosphate-buffered saline
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4621860&req=5

Fig5: Illustration of apoptotic cells at the fracture site. A mass of apoptotic cells (brown cells) was observed around the fracture ends within the callus in the Luc-MSC systemic injection group (a), the local injection group (b), and the PBS control group (c) at 5 weeks following the fracture, but none was observed in the negative control (the normal femur) (d). e-h High-resolution images were, respectively, enlarged from the red outlined areas in a–d. Both living Luc-positive cells (light green cells within red circles) and apoptotic Luc-positive cells (dark green cells within white circles) were found in the MSC systemic injection group (e) and the MSC local injection group (f) at 5 weeks following the fracture, but no Luc-positive cells were found in the PBS control group (g) and the negative control (h). Luc-MSC Luciferase labeled mesenchymal stem cell, MSC mesenchymal stem cell, PBS phosphate-buffered saline
Mentions: To examine the apoptosis level of injected Luc-MSCs, peroxidase staining and immunofluorescence staining were carried out on the same section. A mass of apoptotic cells (brown cells) was observed around the fracture sites within the callus in the Luc-MSC systemic injection group (Fig. 5a), the local injection group (Fig. 5b), and the PBS control group (Fig. 5c) at 5 weeks following the fracture, but none was observed in the negative control (the normal femur) (Fig. 5d).Fig. 5

Bottom Line: The fate and whereabouts of the allogenic mesenchymal stem cells (MSCs) following their transplantation are not well understood.Bone mineral density, bone volume/tissue volume, ultimate load, and E-modulus in the MSC injection groups were significantly higher than those in the PBS group.These findings provide useful information for the use of allogenic MSCs for cell therapy applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics & Traumatology, Faculty of Medicine, Room 904, 9/F, Li Ka Shing Institute of Health Institute, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong, SAR, PR China. huangshuo82@gmail.com.

ABSTRACT

Introduction: The fate and whereabouts of the allogenic mesenchymal stem cells (MSCs) following their transplantation are not well understood. The present study investigated the fate of systemically administrated allogeneic MSCs in mouse fracture healing by using in vivo imaging and immunohistochemistry methods.

Methods: Open femoral fracture with internal fixation was established in 30 FVB mice, which were assigned to three groups receiving phosphate-buffered saline (PBS) injection, MSC systemic injection, or MSC local injection. Luc-MSCs (5 × 10(5)) isolated from the luciferase transgenic mice with FVB background were injected at 4 days after fracture. All animals were terminated at 5 weeks after fracture; examinations included bioluminescence-based in vivo imaging, micro-computer tomography, mechanical testing, histology, immunohistochemistry, and double immunofluorescence staining.

Results: The bioluminescence signals of the Luc-MSCs at the fracture site could be detected for 12-14 days following their injection in the Luc-MSC local injection group, whereas in the Luc-MSC systemic injection group, Luc-MSCs were initially trapped in lungs for about 8-9 days and then gradually redistributed to the fracture site. Bone mineral density, bone volume/tissue volume, ultimate load, and E-modulus in the MSC injection groups were significantly higher than those in the PBS group. Double immunostaining demonstrated that the MSC local injection group had more Luc-positive cells, and there was a higher apoptotic rate at the fracture site than the MSC systemic injection group. Both Luciferase-positive MSCs and osteoblasts were present in the callus in the MSC injection groups at 5 weeks after fracture, suggesting that some of allogenic Luc-MSCs contributed to the new bone formation. Only less than 3 % of injected Luc-MSCs remained at the fracture site in the MSC injection groups at 5 weeks following the fracture, and the rest of the injected Luc-MSCs disappeared.

Conclusions: Our data showed that both systemic and local injection of allogeneic MSCs promoted fracture healing through enhancing biomechanical properties, bone content, and enlarged callus sizes. Immunohistochemistry confirmed that the injected MSCs are still present in the fracture site and can differentiate into osteoblasts to participate in fracture healing even at 5 weeks following the fracture. These findings provide useful information for the use of allogenic MSCs for cell therapy applications.

No MeSH data available.


Related in: MedlinePlus