Related Experiment Videos
Altered expression of SDF-1 and CXCR4 during fracture healing in diabetes mellitus
Michio Arakura1, Sang Yang Lee1, Shunsuke Takahara1
1Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
Purpose:
Diabetes mellitus (DM) is known to impair fracture healing. The purpose of this study was to elucidate and compare the gene expression patterns and localization of stromal cell-derived factor 1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) during fracture healing of the femur in rats with and without DM.
Methods:
Closed transverse fractures were created in the femurs of rats equally divided into a DM group and control group; DM was induced by streptozotocin. At post-fracture days five, seven, 11, 14, 21 and 28, total RNA was extracted from the fracture callus and mRNA expression levels of SDF-1 and CXCR4 were measured by real-time polymerase chain reaction. Localization of SDF-1 and CXCR4 proteins at the fracture site was determined by immunohistochemistry at days 21 and 28.
Results:
SDF-1 expression was significantly lower in the DM group than in the healthy group on days 21 and 28, and showed a significant difference between days 14 and 21 in the healthy group. There was no significant difference in CXCR4 expression levels between the healthy and DM groups at any time point. On day 21 immunoreactivity of SDF-1 and CXCR4 was detected at the fracture site of the healthy group but no immunoreactivity was observed in the DM group. On day 28, immunoreactivity of SDF-1 and CXCR4 was detected at the fracture site in both groups.
Conclusion:
Gene expression and localization of SDF-1 and CXCR4 was altered during fracture healing, which may contribute to the impaired fracture healing in DM.
Insights
Diabetes mellitus impairs bone fracture healing by altering stromal cell-derived factor 1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) expression and localization during femur fracture repair in rats.
Area of Science:
- Biomedical research
- Orthopedics
- Endocrinology
Background:
- Diabetes mellitus (DM) is a metabolic disorder known to negatively impact bone fracture healing.
- Stromal cell-derived factor 1 (SDF-1) and its receptor CXC chemokine receptor 4 (CXCR4) play crucial roles in tissue repair and regeneration.
- Understanding the molecular mechanisms underlying impaired fracture healing in diabetic patients is critical for developing effective therapeutic strategies.
Purpose of the Study:
- To investigate and compare the gene expression patterns and protein localization of SDF-1 and CXCR4 during femur fracture healing in a rat model of diabetes mellitus.
- To elucidate the potential role of SDF-1 and CXCR4 in the compromised fracture healing observed in diabetic conditions.
Main Methods:
- A closed transverse femur fracture model was established in rats, with diabetes mellitus induced by streptozotocin.
- Gene expression of SDF-1 and CXCR4 was quantified using real-time polymerase chain reaction at multiple time points post-fracture.
- Protein localization of SDF-1 and CXCR4 was assessed via immunohistochemistry at specific time points.
Main Results:
- SDF-1 mRNA expression was significantly reduced in diabetic rats compared to control rats on days 21 and 28 post-fracture.
- While CXCR4 mRNA levels did not differ significantly between groups, SDF-1 and CXCR4 protein immunoreactivity was absent in the fracture callus of diabetic rats on day 21, but present in both groups on day 28.
- These findings suggest altered temporal expression and localization of SDF-1 and CXCR4 in the context of diabetic fracture healing.
Conclusions:
- Altered gene expression and protein localization of SDF-1 and CXCR4 are observed during fracture healing in diabetic rats.
- These molecular changes may contribute to the impaired fracture healing associated with diabetes mellitus.
- Targeting the SDF-1/CXCR4 pathway could be a potential therapeutic approach to improve fracture healing in diabetic patients.