脉冲电磁场对去卵巢大鼠骨量和 Wnt/β-连环蛋白信号通路的影响。

Effects of pulsed electromagnetic fields on bone mass and Wnt/β-catenin signaling pathway in ovariectomized rats.

机构信息

Rehabilitation Key Laboratory of Sichuan Province, Department of Rehabilitation, West China Hospital, Sichuan University, Chengdu, People's Republic of China.

出版信息

Arch Med Res. 2012 May;43(4):274-82. doi: 10.1016/j.arcmed.2012.06.002. Epub 2012 Jun 13.

DOI:10.1016/j.arcmed.2012.06.002

PMID:22704852

Abstract

BACKGROUND AND AIMS

The therapeutic effects of pulsed electromagnetic fields (PEMFs) on osteoporosis have been documented. However, the precise mechanisms by which PEMFs elicit these favorable biological responses are still not fully understood. This study aimed to systematically investigate the effects of PEMFs on bone mass and Wnt/β-catenin signaling pathway in ovariectomized rats.

METHODS

Thirty 3-month-old female Sprague Dawley rats were randomly assigned to one of three groups: sham-operated control (sham), ovariectomy (OVX), and ovariectomy with PEMFs treatment (PEMFs). One week following ovariectomy surgery, rats in the PEMFs group were exposed to PEMFs for 40 min/day, 5 days/week, for 12 weeks.

RESULTS

After 12-week interventions, serum 17β-estradiol and bone-specific alkaline phosphatase levels increased in the PEMFs group. Bone mineral density of the femur and the fifth lumbar vertebral body also increased in the PEMFs group. Histomorphometrical studies showed that PEMFs improved trabecular area, trabecular width, and trabecular number by 77.50%, 17.38% and 51.06%, respectively, and reduced trabecular separation by 44.28% compared with the OVX group. Biomechanical studies showed that PEMFs increased maximum load and energy to failure in the fifth lumbar vertebral body. Quantitative real-time RT-PCR analysis showed that PEMFs increased the mRNA expressions of Wnt3a, low-density lipoprotein receptor-related protein 5(LRP5), β-catenin, c-myc and runt-related gene 2 (Runx2), and reduced dickkopf1 (DKK1) in ovariectomized rats. However, mRNA expression of Axin2 was not affected by PEMFs.

CONCLUSIONS

PEMFs can prevent ovariectomy-induced bone loss and deterioration of bone microarchitecture and strength, at least partly, through activation of Wnt/β-catenin signaling pathway.

摘要

背景与目的

脉冲电磁场（PEMFs）对骨质疏松症的治疗效果已有记载。然而，PEMFs 产生这些有利的生物学反应的确切机制仍不完全清楚。本研究旨在系统研究 PEMFs 对去卵巢大鼠骨量和 Wnt/β-catenin 信号通路的影响。

方法

将 30 只 3 月龄雌性 Sprague Dawley 大鼠随机分为三组：假手术对照组（sham）、去卵巢组（OVX）和去卵巢加 PEMFs 治疗组（PEMFs）。去卵巢手术后 1 周，PEMFs 组大鼠每天接受 PEMFs 照射 40 分钟，每周 5 天，共 12 周。

结果

干预 12 周后，PEMFs 组大鼠血清 17β-雌二醇和骨碱性磷酸酶水平升高。股骨和第五腰椎骨密度也增加。组织形态计量学研究显示，PEMFs 可使小梁面积、小梁宽度和小梁数量分别增加 77.50%、17.38%和 51.06%，并使小梁分离减少 44.28%，与 OVX 组相比。生物力学研究表明，PEMFs 增加了第五腰椎的最大载荷和破坏能。实时定量 RT-PCR 分析显示，PEMFs 增加了去卵巢大鼠 Wnt3a、低密度脂蛋白受体相关蛋白 5（LRP5）、β-catenin、c-myc 和 runt 相关基因 2（Runx2）的 mRNA 表达，降低了 dickkopf1（DKK1）的 mRNA 表达。然而，PEMFs 对 Axin2 的 mRNA 表达没有影响。