Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
Vitam Horm. 2017;105:161-179. doi: 10.1016/bs.vh.2017.02.003. Epub 2017 Mar 23.
Erythropoietin (Epo) is the main hormone that regulates the production of red blood cells (hematopoiesis), by stimulating their progenitors. Beyond this vital function, several emerging roles have been noted for Epo in other tissues, including neurons, heart, and retina. The skeletal system is also affected by Epo; however, its actions on bone are, as yet, controversial. Here, we review the seemingly contradicting evidence regarding Epo effects on bone remodeling. We also discuss the evidence pointing to a direct vs indirect effect of Epo on the osteoblastic and osteoclastic cell lineages. The current controversy may derive from a context-dependent mode of function of Epo, namely, opposite skeletal actions during bone regeneration and steady-state bone remodeling. Differences in conclusions deriving from the published in vitro studies may thus relate to the different experimental conditions. Taken together, the current state-of-the-art indicates definite Epo effects on bone cells and points to the complexity of the mode of function.
促红细胞生成素（Epo）是调节红细胞生成（造血）的主要激素，通过刺激其祖细胞来实现。除了这一重要功能外，Epo 在其他组织（包括神经元、心脏和视网膜）中的作用也逐渐被发现。骨骼系统也受到 Epo 的影响；然而，Epo 对骨骼的作用仍存在争议。在这里，我们回顾了关于 Epo 对骨重塑影响的看似矛盾的证据。我们还讨论了指向 Epo 对成骨细胞和破骨细胞谱系的直接和间接作用的证据。目前的争议可能源于 Epo 功能的一种依赖于背景的模式，即骨再生和稳态骨重塑期间的相反骨骼作用。因此，从已发表的体外研究中得出的结论差异可能与不同的实验条件有关。总的来说，目前的最新研究表明 Epo 对骨细胞有明确的影响，并指出了其功能模式的复杂性。
