缝隙连接蛋白43在去卵巢大鼠骨细胞中的表达及其与骨质疏松的关系

Expression of connexin 43 in osteoblasts and osteoclasts of rat models of ovariectomy-induced osteoporosis

目的 探讨去卵巢致骨质疏松大鼠骨细胞中缝隙连接蛋白 4 3(Cx4 3)的表达及意义。 方法 采用 10月龄未孕产Wistar雌性大鼠 30只 ,随机分为去卵巢组、假手术组和尼尔雌醇治疗组。于术后 8周末测量 3组大鼠全身及腰椎骨密度 (BMD) ,采用放免法测定血清雌二醇水平 ,采用SABC免疫组化法观察Cx4 3在成骨细胞和破骨细胞中的表达情况 ,采用 3’ OH末端DNA原位标记技术观察凋亡细胞变化。 结果 术后 8周末去卵巢组全身及腰椎BMD和血清雌二醇水平明显低于假手术组和尼尔雌醇治疗组 (P <0 0 1)。去卵巢组成骨细胞内Cx4 3阳性表达率 (13 80 %±1 14 % )低于假手术组 (6 3 6 0 %± 2 4 6 % )和尼尔雌醇治疗组 (6 3 6 0 %± 2 12 % ) (P <0 0 1) ,而破骨细胞内去卵巢组Cx4 3阳性表达率 (6 6 10 %± 1 37% )高于假手术组 (42 2 0 %± 1 93% )和尼尔雌醇治疗组 (41 80 %± 1 81% ) (P <0 0 1)。去卵巢组成骨细胞的凋亡变化 (49 30 %± 3 86 % )高于假手术组 (2 4 2 0 %± 2 78% )和尼尔雌醇治疗组 (2 5 5 0 %± 3 0 3% ) (P <0 0 1) ,破骨细胞凋亡变化(5 80 %± 1 14 % )低于假手术组 (19 2 0 %± 1 75 % )和尼尔雌醇治疗组 (19 70 %± 1 6 9% ) (P <0 0 1)。而上述观察指标中假手术组和尼尔雌醇治疗?

Objective To investigate the expression of gap junction protein connexin 43(Cx43) in osteoblasts and osteoclasts in rat models of ovariectomy-induced osteoporosis. Methods Osteoporosis models of rats were obtained by bilateral ovariectomy. Thirty female Wistar rats at theweight of 250～300g were equally randomized into ovariectomized group, sham-operation control group and ovariectomized and nilestriol-treated group. Total skeletal and spinal(L 4-6)bone mineral density (BMD) of each rat were measured by DEXA.Levels of estrogen were measured by radioimmunoassay. Expression of Cx43 were observed with immunohistochemical method. Apoptotic cells were examined using the terminal delxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) technique. Results At the end of 8 weeks after operation, total skeletal BMD and L4-6 BMD and level of estrogen of rats in OVX group were significantly lower than those in SHAM group ( P <0.01) . The expression of Cx43 was less in osteoblasts ( 13.80%±1.14% ) and more in osteoclasts ( 66.10%±1.37% )of the OVX group than in the SHAM group and OVX+N group ( P <0.01). Postive expression rats of apoptosis cells ( 49.30%±3.86% ) was increasted in the osteoblasts, but the expression of apoptosis cells ( 5.80%±1.14% ) was less in the osteoclasts of the OVX group than in the SHAM group and OVX+N group ( P <0.01). The above mentioned targets in post-ovariectomized rats treated with nilestriol were close to those SHAM group. Conclusions Osteoporosis in the OVX group is attributed to the lower level of estrogen which may induce the decreased expression of Cx43 in osteoblasts and the increased expression in the osteoclasts which may restrain apoptosis of osteoblasts and stimulate apoptosis of osteoclasts.