Endoplasmic reticulum stress mediates osteocyte death under oxygen-glucose deprivation in vitro.

UNLABELLED: As a vascularized organ, bone is known to be susceptible to ischemia. Ischemic osteonecrosis or skeletal unloading lead to ischemia in bone microenvironment that causes osteocytes to suffer hypoxia and nutrition deprivation.

OBJECTIVE

To explore the effects of Oxygen-glucose deprivation (OGD) on osteocytes and the potential mechanism.

METHODS

OGD model was established in cultured MLO-Y4 cell. Cell damage, intracellular oxidative stress and cell apoptosis were detected at different OGD times (0, 2, 4, 8, 12, 24 h), and the changes in endoplasmic reticulum (ER) stress-related indicators were observed. Furthermore, cells were treated with 4-phenylbutyrate sodium (4-PBA) to inhibit ER stress, and cell damage and oxidative stress level were detected.

RESULTS

The cell viability under OGD exhibited a significantly reduced in a time-dependent manner, and the level of intracellular reactive oxygen species (ROS) were increased, cell apoptosis and ER stress was induced. Inhibition of ER stress can reduce cell death and intracellular ROS levels.

CONCLUSION

Our study demonstrated that ER stress regulates OGD-induced apoptotic cell death in MLO-Y4 cells via intracellular ROS.