Related Experiment Video
Updated: Feb 18, 2026

Improved Methodology for Studying Postnatal Osteogenesis via Intramembranous Ossification in a Murine Bone Marrow Injury Model
Published on: February 7, 2025
Rapamycin facilitates fracture healing through inducing cell autophagy and suppressing cell apoptosis in bone tissues
1Department of Orthopedics, the Affiliated Lianyungang Hospital of Xuzhou Medical University, The First People's Hospital of Lianyungang, Lianyungang, China. dongyuefu@163.com.
Objective:
To investigate the changes in cell autophagy and the molecular mechanism of rapamycin affecting the fracture healing.
Material And Methods:
Sprague-Dawley (SD) rats were used to establish the right femoral shaft fracture models, and then underwent immunofluorescence assay to detect the autophagy level in bone tissues. After model establishment, SD rats were divided into two groups, the control group and the rapamycin group (1 mg/kg/d). Respectively, at the 2nd, 4th, and 6th week, rats were randomly selected from each group for X-ray and Micro-computed tomography (Micro-CT) examinations to determine callus growth, immunofluorescence assay to detect the protein expression of light chain 3 II (LC3 II), immunohistochemistry to evaluate the autophagy level through detecting the expression of Beclin1 in rats, Western blotting assay to detect cell apoptosis in tissues, hematoxylin and eosin staining (HE staining) to evaluate the osteoblastic activity through count of osteoblast in bone tissue at the end of fracture, and measure the expression of vascular endothelial growth factors (VEGF).
Results:
Significant increases were seen in protein expression of cells in bone tissues at the end of fracture. In rapamycin group, callus formation and calcification level in rats were all higher than those in control group; compared with control group, for rats in rapamycin group, cell autophagy was significantly elevated in bone tissues, while cell apoptosis at the end of fracture was reduced with a significant increase in osteoblastic activity. The expression of VEGF in rapamycin group was higher than that in control group.
Conclusions:
Rapamycin can facilitate fracture healing through inducing cell apoptosis and suppressing cell apoptosis in bone tissues.
More Related Videos
Related Concept Videos
mTOR Signaling and Cancer Progression
The mTOR pathway or the...
PI3K/mTOR/AKT Signaling Pathway
Osteoclasts in Bone Remodeling
Fractures: Bone Repair
Minor fractures with no bone displacement are treated by immobilizing the fractured bone using a cast or splint. However, in the case of fractures with displaced bones, the broken bones are repositioned before immobilization to ensure successful healing without deformation and loss of function. The realignment of fractured bone ends is performed through a process called reduction. If the...
Bone Remodeling
Restarting Stalled Replication Forks

