PERK信号通路对实验性绝经后骨质疏松雌性大鼠成骨细胞分化的影响

doi:10.13481/j.1671-587x.20180210

摘要/Abstract

摘要： 目的：探讨实验性雌性大鼠绝经后骨质疏松（PMOP）治疗前后骨组织中PERK、ATF4、Runx2、osterix、RANKL和OPG的变化，阐明PERK信号通路在PMOP发生中的作用。方法：复制雌性大鼠卵巢去势骨质疏松模型。45只大鼠分为正常对照组（大鼠不做处理，15只）、骨质疏松组（雌性大鼠卵巢摘除，15只）和骨质疏松治疗组（大鼠卵巢摘除后尾静脉注射雌激素，15只）。观察各组大鼠血清中Ⅰ型胶原（ColⅠ）、碱性磷酸酶（ALP）和骨钙素（OCN）水平。饲养3个月后取各组大鼠股骨骨干做病理切片，RT-PCR法检测各组大鼠骨组织中PERK、ATF4、Runx2、osterix、RANKL和OPG基因表达水平，Westernblotting法分析PERK、ATF4、Runx2、osterix、RANKL和OPG蛋白表达水平。结果：与对照组比较，骨质疏松组大鼠血清中ColⅠ、ALP和OCN水平明显降低（P<0.05或P<0.01）；与骨质疏松组比较，骨质疏松治疗组大鼠血清中ColⅠ、ALP和OCN水平明显升高（P<0.01）。与对照组比较，骨质疏松组大鼠骨组织中PERK、ATF4、Runx2和osterix基因表达水平明显下降（P<0.05或P<0.01），RANKL基因表达水平明显升高（P<0.01）；与骨质疏松组比较，骨质疏松治疗组大鼠骨组织中PERK、ATF4、Runx2和osterix基因表达水平明显升高（P<0.05或P<0.01），RANKL基因表达水平明显降低（P<0.01）。与对照组比较，骨质疏松组大鼠骨组织中PERK、Runx2和osterix蛋白表达水平明显下降（P<0.05或P<0.01），RANKL蛋白表达水平明显升高（P<0.05或P<0.01）；与骨质疏松组比较，骨质疏松治疗组大鼠骨组织中PERK、Runx2和osterix蛋白表达水平明显上升（P<0.05或P<0.01），RANKL蛋白表达水平明显降低（P<0.01）。HE染色，与对照组比较，骨质疏松组大鼠骨组织中骨吸收陷窝变大，骨吸收增强，导致骨质流失；与骨质疏松组比较，骨质疏松治疗组大鼠骨质吸收减弱，骨骼恢复正常结构。结论：雌性大鼠卵巢切除及注射雌激素治疗后，其骨组织中PERK表达趋势与成骨细胞转录因子Runx2和osterix变化一致，与破骨细胞转录因子RANKL表达相反，提示PMOP发病时成骨细胞功能减弱与PERK表达下降有关。

关键词: 成骨细胞, 破骨细胞, 绝经后骨质疏松, PERK, 转录因子

Abstract: Objective:To investigate the changes of PERK,Runx2,osterix,RANKL and OPG in bone tissue of the female rats with experimental postmenopausal osteoporosis (PMOP) before and after treatment,and to elucidate the role of PERK signaling pathway in PMOP. Methods: The ovariectomized rats were reproduced to osteoporosis models.A total of 45 rats were divided into normal control group (the rats didn't receive any treatment,n=15),osteoporosis group (the rats were ovariectomized,n=15) and osteoporosis treatment group (the ovariectomized rats were injected with estrogen through caudal vein,n=15).The changes of serum collagen Ⅰ (Col Ⅰ),alkaline phosphatase (ALP) and osteocalcin (OCN) of the rats in various groups were observed.Three months after feeding,the femoral shaft of the rats in various groups were taken for pathological section.The gene expression levels of PERK,ATF4,Runx2,osterix,RANKL and OPG in bone tissue of the rats in various groups were detected by RT-PCR; the protein expression levels of PERK,ATF4,Runx2,osterix,RANKL and OPG were detected by Western blotting method. Results: Compared with control group,the levels of serum Col Ⅰ,ALP and OCN in the rats in osteoporosis group were significantly decreased (P<0.05 or P<0.01); compared with osteoporosis group,the levels of serum Col Ⅰ,ALP and OCN of the rats in osteoporosis treatment group were significantly increased (P<0.01).Compared with control group,the gene expression levels of PERK,ATF4,Runx2 and osterix in bone tissue of the rats in osteoporosis group were significantly decreased (P<0.01),and the gene expression level of RANKL was increased(P<0.01); compared with osteoporosis group,the gene expression levels of PERK,ATF4 Runx2 and osterix in bone tissue of the rats in osteoporosis treatment group were significantly increased (P<0.01),and the gene expression level of RANKL was significantly decreased (P<0.01).Compared with control group,the protein expression levels of PERK,Runx2 and osterix in bone tissue of the rats in osteoporosis group were significantly decreased (P<0.05 or P<0.01),and the protein expression level of RANKL were increased(P<0.05 or P<0.01); compared with osteoporosis group,the protein expression levels of PERK,Runx2 and osterix in bone tissue of the rats in osteoporosis treatment group were significantly increased (P<0.05 or P<0.01),and the protein expression level of RANKL was significantly decreased (P<0.01).The HE staining results showed that compared with control group,the bone resorption pits in bone tissue of the rats in osteoporosis group became large with the increased bone absorption,which caused bone loss; compared with osteoporosis group,the resorption in bone tissue of the rats in osteoporosis treatment group was decreased,and the bone structure returned to normal. Conclusion: After the female rats are ovariectomized and injected with estrogen,the expression trends of PERK and osteoblast transcription factors Runx2 and osterix are consistent,in contrast with the osteoclast transcription factor RANKL expression,suggesting that the osteoblast function is reduced and it is related to the decreased expression of PERK in PMOP onset.

Key words: postmenopausal osteoporosis, osteoclast, PERK, osteoblast, transcription factor

中图分类号:

R681

李希宁, 陈晓春, 朱云飞, 曹泾楠, 邹忆婷, 杜霄, 王旗春. PERK信号通路对实验性绝经后骨质疏松雌性大鼠成骨细胞分化的影响[J]. 吉林大学学报(医学版), 2018, 44(02): 260-264.

LI Xining, CHEN Xiaochun, ZHU Yunfei, CAO Jingnan, ZOU Yiting, DU Xiao, WANG Qichun. Effect of PERK signaling pathway on osteoblast differentiation of female rats with experimental postmenopausal osteoporosis[J]. Journal of Jilin University Medicine Edition, 2018, 44(02): 260-264.

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