Fang Bin, Zhang Kailong, Zhang Jie, Chen Zhenda, Xuan Yunxin, Huang Hongbin
Department of Spine Surgery, The Central Hospital Affiliated to Shaoxing University, No. 1 Huayu Road, Keqiao District, Shaoxing City, 312030 Zhejiang Province China.
Beijing Zhongwei Research Center of biological and translational medicine, Beijing, China.
Cytotechnology. 2022 Feb;74(1):65-75. doi: 10.1007/s10616-021-00507-x. Epub 2021 Nov 22.
Mechanical strain regulated osteoclastic differentiation and angiogenesis are crucial for bone modeling and remodeling, and previous data indicate that high-magnitude strain within physiological load regulates osteoclastic differentiation. However, the underlying mechanisms are still not fully understood. In the present study, the RAW264.7 mouse monocyte/macrophage was used as an osteoclast precursor, and the bone marrow-derived macrophages (BMMs) were isolated and cultured in vitro. The above cells were subjected to macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL) for the induction of osteoclast differentiation. Subsequently, the above cells were stretched by differential strain magnitudes to simulate the mechanical stimuli in the physiological conditions, and we found that low-magnitude strain (100 με) increased the expression levels of Acp5, Clcn7, MMP9 and Ctsk to promote osteoclastogenesis, while high-magnitude strain (3000 με) had opposite effects. In addition, we noticed that high-magnitude strain upregulated PTEN to inactivate the PI3K/Akt signaling pathway, and silencing of PTEN abrogated the suppressing effects of high-magnitude strain on osteoclastic differentiation. Next, we screened out that high-magnitude strain downregulated miR-21 to promote PTEN expressions in a competing endogenous RNA (ceRNA)-dependent manner. Finally, upregulation of miR-21 recovered osteoclastic differentiation in RAW264.7 and BMMs cells stimulated with high-magnitude strain. Collectively, our findings suggested that high-magnitude mechanical strain affected osteoclastic differentiation through modulating the miR-21/PTEN/PI3K/Akt signaling cascade, which provided potential strategies for the treatment of bone-related diseases.
The online version contains supplementary material available at 10.1007/s10616-021-00507-x.
机械应变调节破骨细胞分化和血管生成对骨塑形和重塑至关重要，先前的数据表明生理负荷范围内的高幅度应变调节破骨细胞分化。然而，其潜在机制仍未完全了解。在本研究中，RAW264.7小鼠单核细胞/巨噬细胞用作破骨细胞前体，分离并体外培养骨髓来源的巨噬细胞（BMMs）。上述细胞接受巨噬细胞集落刺激因子（M-CSF）和核因子-κB受体激活剂配体（RANKL）以诱导破骨细胞分化。随后，上述细胞通过不同幅度的应变进行拉伸以模拟生理条件下的机械刺激，我们发现低幅度应变（100με）增加了Acp5、Clcn7、MMP9和Ctsk的表达水平以促进破骨细胞生成，而高幅度应变（3000με）则产生相反的作用。此外，我们注意到高幅度应变上调PTEN以失活PI3K/Akt信号通路，并沉默PTEN消除了高幅度应变对破骨细胞分化的抑制作用。接下来，我们筛选出高幅度应变以竞争性内源性RNA（ceRNA）依赖的方式下调miR-21以促进PTEN表达。最后，miR-21的上调恢复了高幅度应变刺激的RAW264.7和BMMs细胞中的破骨细胞分化。总体而言，我们的研究结果表明高幅度机械应变通过调节miR-21/PTEN/PI3K/Akt信号级联影响破骨细胞分化，这为骨相关疾病的治疗提供了潜在策略。
在线版本包含可在10.1007/s10616-021-00507-x获取的补充材料。
