去卵巢大鼠骨质疏松凋亡细胞及其相关因素观察

Apoptotic cells and related factors in ovariectomized rat osteoporosis model

目的 探讨去卵巢大鼠骨细胞凋亡活性及其相关因素。方法 采用 3′ OH末端DNA原位标记技术观察凋亡细胞活性 ;采用免疫组化SABC法观察bcl 2、Fas、转化生长因子 (TGF) β1的表达情况。结果 去卵巢大鼠成骨细胞的凋亡细胞活性为 (4 0 5± 5 2 ) % ,较假手术组 (2 4 5± 3 0 ) %与去卵巢 +尼尔雌醇 /左炔诺孕酮治疗组 [OVX +N/L组 ,(2 6 4± 2 9) % ]明显增加 ,差异有显著性(P <0 0 1) ;去卵巢大鼠破骨细胞的凋亡细胞活性为 (8 4± 1 2 ) % ,明显低于假手术组 (2 4 0± 2 9) %与OVX +N/L组 (2 6 5± 3 1) % ,差异具有显著性 (P <0 0 1)。3组成骨细胞与破骨细胞内bcl 2阳性表达率均较低 ,差异无显著性 (P值均 >0 0 5 ) ;去卵巢大鼠组成骨细胞内Fas(80 0 % )高于假手术组(4 0 0 % )和OVX +N/L组 (4 0 0 % ) ,而破骨细胞内Fas(2 0 0 % )低于假手术组 (70 0 % )和OVX +N/L组(73 3% ) ,后者差异有显著性 (χ2 =7 94,P <0 0 5 ) ,OVX组成骨和破骨细胞内TGFβ1(分别为 2 0 0 %、0 ) ,均低于其他两组 ,前者差异有极显著意义 (χ2 =13 10 4,P <0 0 1)。结论 去卵巢大鼠骨丢失主要是由于雌激素水平低下引起破骨细胞凋亡减少、成骨细胞凋亡活性增加致骨吸收功能明显增加而超过骨形成所致 ;

Objective To investigate the status of apoptosis of osteoblast, osteoclast and the relative factors. Methods Apoptotic cells were examined using in situ end labeling technique. Expressions of bcl 2, Fas and transforming growth factor(TGF)β1 were observed with immunohistochemical method. Results Positive expression rate (40 5±5 2)% of apoptosis cells was significantly increased in the osteoblast, but the expression rate of apoptosis cells (8 4±1 2)% was significantly decreased in the osteoclast of the post ovariectomy rats than in the sham operated rats. The expression of Fas was decreased in osteoclast (20 0%) and increased in osteoblast (80 0%) of the post ovariectomized rats. The expression of TGFβ1 was significantly decreased in the osteoclast (0) and the osteoblast (20 0%) of the post ovariectomized rats. The above mentioned targets in post ovariectomized rats treated with nilestriol/levonorgestrel were close to those sham operated rats ( P >0 05). Conclusions Bone loss in the post ovariectomized rats is attributable to the lower level of estrogen so that the apoptosis cells were decreased in osteoclast but were increased in osteoblast. As a result, the process of bone absorption prevails over that of bone formation. Expression of TGFβ1 depends on stimulation of estrogen. TGFβ1 may stimulate apoptosis of osteoclast and restrain apoptosis of osteoblast. Fas can induce the apoptosis of osteoclast.