Epigenetic regulation of autophagy by histone-modifying enzymes under nutrient stress

Prevention and Co-Management of Breast Cancer-Related Osteoporosis Using Resveratrol

“…Moreover, all three cell types, osteoblasts, osteoclasts, and osteocytes, have contact with ECM molecules through a large number of specific integral membrane receptor proteins, the so-called integrins, which are located both on the surface of bone cells and on ECM molecules, such as collagen type I and fibronectin [42,43] Estrogen is a key hormone for intact bone metabolism, which has been found to influence the expression of integrins involved in the mechanosensation of osteocytes, leading to modified osteoclastogenic paracrine signaling [44] (Figure 1). Moreover, hormones such as estrogen [45] and also conditions such as fasting [46] correlate with the inhibition of autophagy regulators, i.e., the mammalian target of rapamycin (mTOR)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, thereby stimulating the autophagy process in osteoblasts in a positive physiological manner. With regard to estrogen and bone health, there is evidence that estrogen may increase the expression of autophagy proteins including Beclin-1 and LC3 in association with up-regulation of Sirt-1 in osteoblasts and osteocytes [47].…”