雌二醇与雷洛昔芬对体外培养成骨细胞生物学功能的影响及护骨素表达的调控

Effect of raloxifene and estradiol on the biological function and osteoprotegerin expression of osteoblasts in vitro

目的比较雌二醇与雷洛昔芬对体外培养成骨细胞的生物学作用及对护骨素(OPG)表达的影响。方法在新生SD大鼠头颅骨第二代成骨细胞培养液中加入不同浓度的雷洛昔芬,并设立雌二醇阳性对照及空白血清对照组;分别观察成骨细胞的增殖、分化和矿化功能;半定量RT-PCR测定成骨细胞中OPG基因的表达。结果体外培养成骨细胞在加入不同剂量的雷洛昔芬后,细胞增殖率(A570)、OPG蛋白表达与空白对照组相比均无明显差异(P>0.05);但碱性磷酸酶(ALP)活性、矿化结节数明显升高,与空白对照组相比差异显著(P<0.05,P<0.01),且与雷洛昔芬浓度呈量效关系;雌二醇对成骨细胞的A570值、ALP活性、矿化结节数量、OPG表达等的影响和对照组相比均有显著差异(P<0.01)。结论雌二醇对体外成骨细胞生物学功能的影响非常显著,并可上调OPG蛋白表达及表达量;雷洛昔芬对体外成骨细胞分化矿化均有影响,但对增殖影响不显著;对OPG表达也无明显影响。此结果提示雷洛昔芬影响骨代谢可能不通过OPG代谢途径,它对体外成骨细胞的作用机制与雌二醇不完全相同。

Objective To study the effect of raloxifene and estradiol on the biological function and osteoprotegerin expression of osteoblasts in vitro.Methods Different doses of raloxifene and estradiol were added into the medium of the second generation osteoblasts from the shull of newborn SD rats.The proliferation,differentiation,mineralization and osteoprotegerin expression of the osteoblasts in different groups were observed.Results Raloxifene had no significant effects on stimulating the proliferation,the expression of osteoprotegerin and the formation of mineral nodes of the cultured osteoblasts (the trial vs the control,P>0.05).However,raloxifene can significantly improve the alkaline phosphatase activity of the cultured osteoblasts (the trial vs the control,P<0.05).Estradiol significantly increased the proliferation of osteoblasts,and differentiation,minera- lization,expression of osteoprotegerin(P<0.01 vs the control).Conclusion The effects of raloxifene and estradiol on the cultured osteoblasts are different,which implied their different mechanisms in inducing osteoporosis.