Gene Expression of TGF-β Cascade in Osteoporosis

绝经后雌激素缺乏可能导致骨质疏松症。为了验证雌激素在骨再生中的作用，对去卵巢大鼠骨缺损愈合过程中转化生长因子-β超家族及其特异性受体的定位进行了研究。然后给予低钙饲料喂养4个月。拔除上颌第一磨牙，1~8周后固定。组织学观察：OVX大鼠拔牙后3d，拔牙窝内可见纤维组织形成。沿拔牙槽壁可见大量破骨细胞。7天时，拔牙槽内充满纤维组织，沿槽壁开始成骨。14天时形成骨小梁，14天后拔牙槽骨充填。结果：1.正常大鼠在4天内成骨。转化生长因子-β及其受体(I型和II型)的分布与转化生长因子-β及其受体的分布一致。在纤维化区的成纤维细胞中检测到强烈的反应。破骨细胞的反应最为强烈。第7天拔牙窝底的成骨细胞呈强烈反应，但破骨细胞的反应强于成骨细胞。第14天破骨细胞表现出强烈的反应。破骨细胞中的反应最为强烈。28d时，成骨细胞的反应强于破骨细胞。BMP及其受体(IA、IB和II型)在骨再生过程中的定位，在成骨细胞和破骨细胞中检测到强烈的反应。破骨细胞反应较弱，OVX大鼠骨再生较正常大鼠延迟。这可能是转化生长因子-β超家族对破骨细胞的刺激作用。

Postmenopausal deficit of estrogen might cause osteoporosis. For the purpose to verify effects of estrogen in bone regeneration, localizations of TGF-β super family and their specific receptors were investigated during process of bone healing in bone defects in ovariectomized rats (OVX).Rats were ovariectomized. Then the animals receive low calcium diet for 4 months. The upper first molars were extracted, then after 1〜8 weeks then, they were fixed.I. Histological findingsIn the OVX rats, fibrogenesis was observed in the extraction sockets at 3 days after the tooth extractions. A large number of osteoclasts were observed along the wall of the extraction sockets. At 7 days the extraction sockets were filled with fibrous tissue, and bone formation was initiated along the socket walls. At 14 days bone trabecullae wa formed then, the extraction sockets were filled with bone in 14 days. In normal rats bone was formed in 4 days.2. The localizations of TGF-β and receptors (Type I and II)The localizations of TGF-β and receptors showed the same distributions. The intense reaction was detected in the fibroblasts of the regions of fibrogenesis. The most intense reaction was found in the osteoclasts. At 7 days osteoblasts along the bottom of the extraction sockets revealed intense reaction but the reactions of osteoclasts were stronger than those of osteoblasts. At 14 days osteoclats showed intense reaction. The most intense reaction was persisted in the osteoclasts. At 28 days reactions of osteoblasts were stronger than those of osteoclasts.3. The localizations of BMP and receptors (Type IA, IB and II)During the process of bone regenaration, intense reaction was detected in the preosteoblasts and osteoclasts. The reactions of osteoclasts were weak.In OVX rats, bone regeneration was delayed than that of normal rats. This might cause stimulation of TGF-β super family to the osteoclasts.