Expression of sSema4D in the serum of mice with osteoporosis / 医学研究生学报

ABSTRACT

Objective Sema4D, as the earliest known immunosuppressive agent, may be involved in the development and progression of osteoporosis. This study aimed to investigate the relationship between sSema4D and osteoporosis.Methods The model of osteoporosis was established in 50 three-month-old C57 mice by gavage of 0.9% retinoic acid and another 50 mice were taken as controls, which received gavage of 0.9% sodium chloride, all at 90 mL/kg for 21 days. Micro-CT scanning of the proximal tibial metaphysis bone tissue 3D reconstruction were performed for observation of the structure, shape, arrangement, direction and number of the trabeculae. The CT values of the area of interest in the proximal tibia metaphysis were determined and the trabecular parameters were obtained with the Inveon Research WorkPlace software. The pathological changes of the bone collagen fibers in the femur and tibia were observed by Van Gieson staining, and the level of serum sSema4D was detected by ELISA.Results Compared with the controls, the osteoporosis model mice showed significant decreases in the trabecular number (7.0 mm vs 5.8 mm, P<0.05), thickness (0.08 mm vs 0.06 mm, P<0.05) and volume fraction (0.5% vs 0.3%, P<0.01), but a marked increase in the trabecular separation (\[0.54±0.12\] mm vs \[0.69±0.13\] mm, P<0.05). Van Gieson staining manifested scarce collagen fibers in the osteoporosis model mice, loosely and disorderly arranged, some poorly connected, dissolved and fractured, with the marrow cavity increased. The level of serum sSema4D was significantly higher in the osteoporosis group than in the control (P<0.01).Conclusion Serum sSema4D may contribute to the incidence of osteoporosis.