Irisin ameliorates bone loss in ovariectomized mice

Abstract

Purpose: This study aimed to evaluate the effects of irisin on bones of ovariectomized (OVX) mice, to explore a possible treatment for postmenopausal osteoporosis.

Methods: The OVX mice were treated with intraperitoneal injections of recombinant irisin (r-irisin) or saline twice a week for 5 weeks. The trabecular bone structure of the femur, the bone strength of the tibia, and serum parameters were assessed.

Results: Treatment with r-irisin prevented the trabecular bone loss of the OVX mice. The r-irisin-treated OVX mice exhibited a greater bone microarchitecture, with significantly increased bone mineral density, bone volume to tissue volume ratio, connection density, and trabecular number parameters compared to those of the saline-treated OVX mice. The improved bone microarchitecture induced an increased bone stiffness in r-irisin-treated OVX mice. Consistently, the OVX mice treated with r-irisin showed a significantly increased number of osteoblasts on the trabecular surface and a significantly decreased number of osteoclasts. The r-irisin-treated OVX mice also had a higher osteocalcin level and a lower tartrate-resistant acid phosphatase concentration in serum.

Conclusion: Irisin increases osteoblasts and decreases the number of osteoclasts, which leads to the maintenance of bone mass and quality in OVX mice. Irisin likely preserves the bone microarchitecture via building a ‘new balance’. Therefore, our study extended the understanding of the role of irisin in bone metabolism and revealed the possibility of therapeutic application of irisin for postmenopausal osteoporosis.

摘要

目的：评价鸢尾素对去卵巢(OVX)小鼠骨骼的影响, 探索治疗绝经后骨质疏松症可能的方法。方法：采用重组鸢尾素(r-Irisin)或生理盐水腹腔注射治疗OVX小鼠, 每周2次, 共5周。评估股骨的松质骨结构、胫骨的骨强度和血清参数。结果：重组鸢尾素治疗可防止去卵巢小鼠骨小梁丢失。重组鸢尾素处理的OVX小鼠表现出更大的骨微结构, 与生理盐水处理的OVX小鼠相比, 骨密度、骨体积与组织体积比、连接密度和骨小梁数量参数显著增加。改进的骨微结构诱导r-鸢尾素治疗的去卵巢小鼠的骨硬度增加。一贯地, 使用r-鸢尾素治疗的OVX小鼠显示骨小梁表面的成骨细胞数量显著增加, 而破骨细胞数量显著减少。重组鸢尾素处理的去卵巢小鼠血清中骨钙素水平较高, 抗酒石酸酸性磷酸酶浓度较低。结论：鸢尾素增加成骨细胞数量, 减少破骨细胞数量, 从而维持去卵巢小鼠的骨量和骨质。鸢尾素可能通过建立一种“新的平衡”来保护骨骼微结构。因此, 我们的研究扩大了人们对鸢尾素在骨代谢中作用的认识, 并揭示了鸢尾素治疗绝经后骨质疏松症的可能性。

Keywords:

• Postmenopausal osteoporosis
• ovariectomized
• exercise-induced irisin
• bone parameters

Potential conflict of interest

The authors declare no conflict of interest.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This project was supported by Scientific Research Projects of The National Natural Science Fund [81671421]; Scientific Research Projects of Health and Family Planning Commission of Sichuan Province [16ZD016].