Objective To investigate the expression levels of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B l igand (RANKL) mRNAs in BMSCs in patients suffering glucocorticoid-induced necrosis of the femoral head (GNFH), and to discuss the relationshi p between OPG/RANKL system and GNFH. Methods The bone tissue and BMSCs of femoral head were collected from 35 patients suffering GNFH (experimental group) and from 21 patients suffering fracture of femoral neck (control group). The ratio of men to women was 4 ∶ 3 in two groups, aged 41 to 70 years (mean 55.34years in the experimental group and mean 55.33 years in the control group). The patients of experimental group received over 3 weeks’ glucocorticoid treatment or more than 1 week’s high-dose glucocorticoid therapy in recent 2 years, but patients of the control group did not receive more than 1 week’s hormone therapy. In 2 groups, the microstructure of bone tissue of femoral head was detected by HE staining. The BMSCs were isolated and cultured by adherent-wall method; the expression levels of OPG and RANKL mRNAs were examined by real-time quantitative polymerase chain reaction and the ratio of OPG mRNA to RANKL mRNA was caculated. Results Bone trabeculae and bone units were replaced by interrupted bone fragments, which were surrounded by inflammation and granulation tissue and few osteocytes were seen in bone lacunae in the experimental group. In control group, bone trabeculae and bone units were made by complete lamellar bone which surrounded blood vessels and osteocytes were seen in lacunae. The expression levels of OPG mRNA in the experimental group (0.37 ± 0.12) was significantly lower than that in the control group (0.47 ± 0.13), and the levels of RANKL mRNA in the experimental group (1.12 ± 0.39) was significantly higher than that in the control group (0.84 ± 0.24), showing statistically significant difference (P lt; 0.05). The ratio of OPG mRNA to RANKL mRNA in the experimental group (0.37 ± 0.17) was significantly lower than that in the control group (0.61 ± 0.26, P lt; 0.05). Conclusion The GNFH may be related to the expression levels of OPG mRNA and RANKL mRNA in BMSCs.
Objective To evaluate sex determining region of the Y (Sry) as a engrafting track of the transplanted BMSCs survival and new bone formation in the osteonecrosis of the femoral head (ONFH) of rabbit. Methods Fortynine 4-5-month-old New Zealand White rabbits were included, weighing 2.0-2.5 kg, 48 females and 1 male. BMSCs of the rabbits were isolated by density gradient separation method, the third passage cells were marked by 1, 1’-dioctadecyl-3, 3, 3’, 3’-tetramethyl indocarbocyanine perchlorate (DiI) and the concentration of cell suspension was 2.5 × 108/ mL. The animal model of ONFH were establ ished with 48 female rabbits by injecting l iquid nitrogen, and femoral head was not dislocated.The animal model were divided into 3 groups, 16 rabbits in each group. Group A only establ ished animal model as control. Autologous BMSCs (4 μL) marked by DiI was transplanted in the ONFH models of the group B. Allogenic BMSCs (4 μL) marked by DiI was transplanted in ONFH models of the group C. The femoral head were observed by X-ray, HE staining and Masson staining, and the regenerating trabecular volume percentages was determined at 2, 4, 6 and 8 weeks after operation respectively. The examples of the heart, lung, l iver, spleen and kidney were obtained. The transplanted BMSCs were traced by fluorescence microscope, the Sry gene expression was detected by PCR for cells survival. Results All rabbits survived till the end of experiment. The X-ray showed gradual necrosis in the femoral head of group A. HE and Masson staining results indicated that compared with the group A, the recovery condition of the necrotic femoral head in the groups B and C was better. At each time of groups B and C, the regenerating trabecular volume percentages were higher than that of the group A significantly (P lt; 0.01). There was no significant difference between groups B and C (P gt; 0.05). The cells marked by DiI were not founded in the tissues of the heart, lung, l iver, spleen and kidney in groups B and C at each time. PCR showed that the expression of Sry gene were not observed at the heart, lung, l iver, spleen and kidney of three groups at each time. The expression of Sry gene was clearly identified in the femoral head of all 16 rabbits in the group C at each time point. Conclusion Allografting of BMSCs transplanted into the femoral head can survive and induce new bone formation without redistribution.