Mechanotransduction is pivotal in the maintenance of homeostasis in different tissues and involves multiple cell signaling pathways. In bone, mechanical stimuli regulate the balance between bone formation and resorption; osteocytes play a central role in this regulation. Dysfunctions in mechanotransduction signaling or in osteocytes response lead to an imbalance in bone homeostasis. This alteration is very relevant in some conditions such as osteoporosis and aging. Both are characterized by increased bone weakness due to different causes, for example, the increase of osteocyte apoptosis that cause an alteration of fluid space, or the alteration of molecular pathways. There are intertwined yet very different mechanisms involved among the cell-intrinsic effects of aging on bone, the cell-intrinsic and tissue-level effects of estrogen/androgen withdrawal on bone, and the effects of reduced mechanical loading on bone, which are all involved to some degree in how aged bone fails to respond properly to stress/strain compared to younger bone. This review aims at clarifying how the cellular and molecular pathways regulated and induced in bone by mechanical stimulation are altered with aging and in osteoporosis, to highlight new possible targets for antiresorptive or anabolic bone therapeutic approaches.

机械转导对于维持不同组织中的体内平衡至关重要，并且涉及多个细胞信号通路。在骨骼中，机械刺激可调节骨骼形成与吸收之间的平衡。骨细胞在该调节中起着核心作用。机械转导信号或骨细胞反应中的功能障碍导致骨稳态失衡。在某些情况下，例如骨质疏松症和衰老，这种改变非常重要。两者的特征都是由于不同原因引起的骨无力增加，例如，引起细胞液空间改变或分子途径改变的骨细胞凋亡增加。衰老对骨骼的细胞内在影响涉及多种相互关联的机制，雌激素/雄激素戒断对骨骼的细胞内在和组织水平影响，以及对骨骼的机械负荷降低的影响，与年轻的骨骼相比，这些都在一定程度上影响了老年骨骼对压力/应变的正确反应。这篇综述的目的是阐明如何通过机械刺激来调节和诱导骨骼中的细胞和分子途径随着年龄的增长和骨质疏松症而改变，以强调抗吸收或合成代谢性骨治疗方法的新目标。