Study Of Caspase-3 Mediated Regulation On Osteogenesis Of Osteoblast In ANFH

Objective To investigate the expression and role of Caspase-3 during the development of non-traumatic avascular/aseptic necrosis of femoral head(ANFH).Methods The femoral heads from 22 ANFH patients were devided into groupâ… (6 cases),â…¡(8 cases),â…¢(8 cases)according to the progress of the disease, those from 19 patients in the acute stage of femoral neck fracture were involved as the control. The level of apoptosis was compared in terms of the percentages of TUNEL positive osteocytes and empty osteocyte lacunae,the activity of Caspase-3 was detected by colorimetric method, the capacity of osteogenesis was established by means of staining cultured osteoblasts with alizarin red S. Furthermore, the osteoblasts from the groupâ… femoral heads were treated with the specific inhibitor of Caspase-3, and mRNA expression level of both some regulators and an osteogenesis indicating molecule were detected by means of RT-PCR.Results Both the pecentages of empty osteocyte lacunae and the pecentages of TUNEL positive osteocytes increased significantly with the developing of ANFH. The activity of Caspase-3 in ANFH groups were higher than in the fracture gourp significantly, but did not increase with the progress of the disease. The osteogenetic capacity in terms of the percentage of area stained by aliarin red S was even higher in groupâ… than in control, so was the expressing level and activity of Caspase-3, both of the two index decreased with further developments of ANFH, with significant statistical differences among groups(P<0.05). Caspase-3 activity was statistically significantly related with the capacity of osteogenesis (P<0.05). Deep suppression of Caspase-3 activity led to significant down-regulation of the index of osteogensis, while modest suppresion was in favor of osteogenesis. It was the expressing level of Dlx5 and Msx2 that changes in Caspase-3 activity could affect more significantly. Conclusion 1) During the development of ANFH, Caspase-3 is involved in apoptosis in some degree. 2) Furthermore, Caspase-3 could also promote osteogenesis in ANFH, modulating the expression and activity of Dlx5 and Msx2 may be a pathway of regulation on osteogenesis by Caspase-3. 3) Caspase-3 acts as not only the executor of apoptosis, but also a crucial supporter of osteogenesis and repairments, the development of ANFH means the Caspase-3-activity-affected firstly increasing and secondly decreasing of osteogenetic capacity, and progressive rising of apoptosis level.