ABSTRACT
Objective:To explore the relationship between the transforming growth factor-β (TGF-β) signaling pathway and steroid-induced osteonecrosis of the femoral head in young rabbits.Methods:Sixty 8-week-old rabbits weighing 1.5-2.0 kg were randomly divided into steroid injection group (48 cases) and control group (12 cases). Rabbits in the former group were injected with Prednisolone Acetate 7.5 mg/kg into bilateral gluteal muscles twice a week for 8 weeks, and those with successful modeling were included in the disease group; otherwise, they were included in the non-disease group.Rabbits in control group were similarly injected with the same volume of 9 g/L saline.Penicillin sodium 50 000 U/rabbit was injected once a week for preventing infection.After 8 weeks of injection, CT was performed in all the experimental animals.They were then sacrificed for collecting bilateral femoral heads.Expression levels of TGF-β1, TGF-β2, Smad2 and Smad3 in the femoral head were detected by enzyme linked immunosorbent assay (ELISA), and the mRNA level of Runx2 in the femoral head was detected by quantitative real-time PCR (qPCR), the expression differences of related factors in each group were compared.Results:In steroid injection group (48 cases), 6 rabbits were sacrificed, and 32 survived, involving 6/32 cases (18.75%) experimental animals with positive avascular necrosis (disease group), and 26 negative ones (non-disease group). ELISA data showed that expression levels of TGF-β1 in control group, non-disease group and disease group were (77.12±14.62) ng/L, (90.17±11.90) ng/L and (126.14±25.66) ng/L, respectively ( t=3.35, 4.24, all P<0.05). The expression levels of TGF-β2 in control group, non-disease group and disease group were (74.54±7.63) ng/L, (89.24±9.51) ng/L and (109.74±16.45) ng/L, respectively ( t=4.12, 5.65, all P<0.01). The expression levels of Smad2 in control group, non-disease group and disease group were (17.74±2.72) μg/L, (23.82±3.58) μg/L and (31.28±3.88) μg/L, respectively ( t= 4.54, 7.99, all P<0.01). The expression levels of Smad3 in control group, non-disease group and disease group were (1.76±0.52) μg/L, (2.39±0.45) μg/L and (3.53±0.47) μg/L, respectively ( t=5.60, 6.71, all P<0.01). qPCR data showed that the mRNA levels of Runx2 in control group, non-disease group and disease group were 1.02±0.17, 1.27±0.14, and 1.72±0.11, respectively ( t=7.60, 8.91, all P<0.01). Conclusions:TGF-β is up-regulated in the model of steroid-induced osteonecrosis of the femoral head in young rabbits, which stimulates the proliferation and differentiation of osteoblasts and osteoclasts, and triggers the process of bone remodeling.The TGF-β signaling pathway involved in the repair of necrotic bone.
ABSTRACT
BACKGROUND: Recent studies have shown that TCM massage can alleviate or even reverse the progression of muscle fibrosis, so it is speculated that massage can also improve the pathological changes of gluteal muscle contracture. OBJECTIVE: To evaluate the role of massage on gluteal muscle contracture and the relevant mechanism. METHODS: Twenty young rabbits were divided into an experimental group and a control group, with penicillin and benzyl alcohol injection for 8 weeks respectively. Besides, the experimental group received massage therapies for 4 weeks, whereas the control group had no specific intervention. Cell morphology and structure were observed using hematoxylin and eosin staining, Masson staining and Sirius red staining. Expression of transforming growth factor-pi in the rabbit model of gluteal muscle contraction was measured using immunohistochemistry, reverse transcription PCR and western blot assays. The study protocol was approved by the Ethics Committee of Peking University Shenzhen Hospital in China. RESULTS AND CONCLUSION: The experimental group had significantly less hyperplasia of fiber tissue compared with the control group (F < 0.05). The expression levels of collagen type I and transforming growth factor-31 were significantly increased in the control group compared with the experimental group, as determined by reverse transcription PCR, western blot assay and immunohistochemical staining (P < 0.05). Therefore, massage therapy can alleviate the progression of gluteal fibrosis, which is expected to provide a new idea for the research and treatment of gluteal muscle contracture.
ABSTRACT
PURPOSE: To evaluate and compare the spontaneous regeneration repair process in femoral bone defects in 6-week-old rabbits and to compare the healing time periods between different rabbit groups. MATERIALS AND METHODS: Bone defects were created at the femur mid-shaft and an external fixator was applied in 50 rabbits. The periosteum was resected in 10 rabbits (defect size: 15%, 25%) and left untouched in the remaining rabbits. Forty rabbits were divided into four groups according to the percentage of bone defects (15%, 20%, 25%, 30%). Radiographs were taken weekly to evaluate the bone regeneration and union. The bone union time was measured between the osteotomy and the cortico-medullary differentiation by examining radiographs. The healing index was defined as the union time (week) per amount (cm) of bone defect. Eight rabbits, 2 from each groups with the bone defects, were investigated by histopathologic examination. RESULTS: The mean union time was approximately 7.0 to 7.3 weeks. The healing index in groups that had a large percentage of bone defects was less than in groups that had a small percentage of bone defects. The periosteum-resected group did not show bone regeneration. Histopathologic examinations showed intramembranous and atypical endochondral ossifications along the periosteum and typical endochondral ossification at the center of the bone defects. CONCLUSION: Spontaneous bone regeneration may be used in children to fill the bone defect instead of performing an internal bone transport. Spontaneous bone regeneration is useful in cases of mid-shaft bone defects or when the remaining bone fragments are large enough for an external fixation application.