Expression Level Of The TGF-β1, MMP-2, Run-X2and BGP In Bone Tissue Of Steroidinduced Necrosis Of Femoral Head

PurposeWe will observe the expression of transforming growth factor-β1, Matrix metal oproteinase-2, runt-related transcription factor2, and bone gla protein, and we will explore its action mechanism in hormonal necrosis of bone repair.Method(1) Animal Testing:20healthy and ordinary New Zealand rabbits will be divided into two groups(10for experimental group and10for control group) according to completely randomized principle. Ear intravenous injection of12.5μg/kg lipopolysaccharide should be performed to the rabbits in experimental group, and repeated administration should be performed24h later. After the injection, intragluteally injection of40mg/kg methylprednisolone should be performed for3times and every24h once. Injecting of equal amount of physiological saline should be performed to both groups at the same time.2months after the last injection of methylprednisolone sodium succinate for injection, X radiographic examination and MRI examination should be performed to rabbits of both two groups. After the image examination,20rabbits should be killed by excessive anesthesia, and femoral head specimen should be fixed and decalcified. After a series of dehydration, the paraffin embedding should be performed, and deal it into spices then HE stain. Pathological examination of specimens should be performed and test the expression level of TGF-β1, MMP-2, and bone gla protein in femoral head bone tissue of rabbit with immunohistochemistry and test the expression level of Run-X2signal in femoral head bone tissue of rabbit with QPCR examination at last.(2) Clinical Research:From October,2013to February,2014, as for the14cases in three department of orthopedics First Affiliated Hospital of Guangzhou University of Chinese Medicine which need replacement of total hip(7 cases in experimental group are steroid induced necrosis of the femoral head patients and the other7in control group aretranscervical fracture, developmental dysplasia of hip and osteoarthritis patients),14femoral head specimens should be fixed and decalcified. After a series of dehydration, the paraffin embedding should be performed, and deal it into spices then HE stain. Pathological examination of specimens should be performed and test the expression level of TGF-β1, MMP-2, and bone gla protein in femoral head bone tissue of rabbit with immunohistochemistry and test the expression level of Run-X2signal in femoral head bone tissue of rabbit with QPCR examination at last.Result1. Animal Testing:The X radiographic examination, MRI examination and pathological examination of rabbits in experimental group all show the femoral head necrosis, but those of control group do not. The expression level of TGF-β1, MMP-2and bone gla protein in femoral head bone tissue from experimental group are all less than those from control group with immunohistochemistry, and the divergence is of statistical significance (mean value of P<0.05). The expression level of RunX2in femoral head bone tissue from experimental group are all less than those from control group with QPCR, and the divergence is of statistical significance (mean value of P<0.05)2. Clinical Research:Pathological examinations of the experimental group all show the femoral head necrosis, but those of control group do not. The expression level of TGF-β1, MMP-2and bone gla protein in femoral head bone tissue from experimental group are all less than those from control group with immunohistochemistry, and the divergence is of statistical significance (mean value of P<0.05).The expression level of RunX2in femoral head bone tissue from experimental group are all less than those from control group with QPCR, and the divergence is of statistical significance (mean value of P<0.05)ConclusionThe mechanism of femoral head necrosis may be related to the excessively low expression level of TGF-β1, MMP-2, RunX2and bone gla protein in femoral head bone tissue.