Related Experiment Video
Updated: Aug 8, 2025
Improved Methodology for Studying Postnatal Osteogenesis via Intramembranous Ossification in a Murine Bone Marrow Injury Model
Published on: February 7, 2025
Impaired function of skeletal stem cells derived from growth plates in ovariectomized mice
1Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.
Introduction:
Mouse skeletal stem cells (mSSCs, CD45-Ter119-Tie2-CD51+Thy-6C3-CD105-CD200+population) are identified in growth plates (GP) and play important roles in bone regeneration. However, the role of mSSCs in osteoporosis remains unclear.
Materials And Methods:
The GP were stained by HE staining, and the mSSC lineage was analyzed by flow cytometry at postnatal of 14 days and 30 days in wild-type mice. The mice (8 weeks) were either sham operated or ovariectomy (OVX) and then sacrificed at 2, 4 and 8 w. The GP were stained by Movat staining, and mSSC lineage was analyzed. Then, mSSCs were sorted by fluorescence-activated cell sorting (FACS); the clonal ability, chondrogenic differentiation and osteogenic differentiation were evaluated, and the changed genes were analyzed by RNA-seq.
Results:
The percentage of mSSCs were decreased with the narrow GP. Heights of GP were decreased significantly in 8w-ovx mice compared with 8w-sham mice. We found the percentage of mSSCs were decreased in mice at 2w after ovx, but the cell numbers were not changed. Further, the percentage and cell numbers of mSSCs were not changed at 4w and 8w after ovx. Importantly, the clonal ability, chondrogenic differentiation and osteogenic differentiation of mSSCs were impaired at 8w after ovx. We found 114 genes were down-regulated in mSSCs, including skeletal developmental genes such as Col10a1, Col2a1, Mef2c, Sparc, Matn1, Scube2 and Dlx5. On the contrary, 526 genes were up-regulated, including pro-inflammatory genes such as Csf1, Nfkbla, Nfatc2, Nfkb1 and Nfkb2.
Conclusion:
Function of mSSCs was impaired by up-regulating pro-inflammatory genes in ovx-induced osteoporosis.
Insights
Osteoporosis impairs mouse skeletal stem cell (mSSC) function by increasing inflammatory genes. This study reveals how mSSCs in growth plates are affected by ovariectomy-induced osteoporosis.
Area of Science:
- Stem cell biology
- Osteoporosis research
- Skeletal development
Background:
- Mouse skeletal stem cells (mSSCs) reside in growth plates and are crucial for bone regeneration.
- The specific role of mSSCs in the context of osteoporosis has not been fully elucidated.
Purpose of the Study:
- To investigate the impact of osteoporosis on mSSC function and characteristics.
- To identify molecular changes in mSSCs following ovariectomy (OVX).
Main Methods:
- Ovariectomy (OVX) was performed on mice to induce osteoporosis.
- Growth plates and mSSC populations were analyzed at various time points post-OVX using histology and flow cytometry.
- Sorted mSSCs were assessed for clonal ability, differentiation potential, and gene expression changes via RNA-seq.
Main Results:
- OVX led to decreased growth plate height and a transient decrease in mSSC percentage.
- While mSSC numbers remained unchanged at later time points, their clonal ability and differentiation potential (chondrogenic and osteogenic) were significantly impaired 8 weeks post-OVX.
- RNA-seq revealed downregulation of skeletal developmental genes and upregulation of pro-inflammatory genes in mSSCs from OVX mice.
Conclusions:
- Ovariectomy-induced osteoporosis impairs the function of mouse skeletal stem cells.
- The functional impairment of mSSCs is associated with the upregulation of pro-inflammatory genes.
