Figure 5.

Potential factors and mechanism involved in the liver-bone axis. Various endocrine factors (IGF-1, FGF21, hepcidin, vitamin D, OC, OPN, LCAT, fetuin-A, PGs, BMP2/9, IL-1/6/17, TNF-α) and key genes (SIRT2, ALDH2, TFR2, SPTBN1, ZNF687, SREBP2) might be involved in the regulation of liver-bone axis in different liver injuries induced bone loss. In addition to classical metabolic pathways such as inflammation and oxidative stress, iron metabolism, cholesterol metabolism, lipid metabolism and immune metabolism mediated by the liver-bone axis might also play some roles in regulating bone loss.