LOX-1 silencing activates the PI3K/AKT pathway to inhibit ox-LDL-induced apoptosis of THVECs.

OBJECTIVE

This study aimed to investigate the mechanism by which the LOX-1/PI3K/AKT signaling axis regulates oxidized low-density lipoprotein (ox-LDL)-induced apoptosis in type H bone vascular endothelial cells (THVECs).

METHODS

Primary THVECs were isolated from rat trabecular bone and identified via coimmunofluorescence staining for CD31 and endomucin (EMCN). The cells were divided into four groups: control, ox-LDL (100 μg/mL), ox-LDL + LV (lentiviral LOX-1 knockdown), and ox-LDL + CON (LV-control). Additionally, an AKT inhibitor (MK-2206) was used to verify the role of PI3K/AKT signaling. Western blotting (WB) was used to measure the protein levels of LOX-1, PI3K, phosphorylated PI3K (p-PI3K), AKT, phosphorylated AKT (p-AKT), Bax,Cleaved-caspse 3,BMP2 and OPN. Flow cytometry was used to detect apoptosis rate and ROS (Reactive Oxygen Species) levels.

RESULTS

ox-LDL treatment significantly induced apoptosis in THVECs cells, upregulated the expression of LOX-1 and apoptoic proteins, promoted reactive oxygen species production, impaired bone remodeling, and reduced the phosphorylation levels of PI3K and AKT. Lentivirus-mediated LOX-1 knockdown reversed ox-LDL-induced endothelial dysfunction and promoted angiogenesis.

CONCLUSION

ox-LDL induces the silencing of the LOX-1 pathway, activates the PI3K/AKT pathway, promots apoptosis, and affects bone remodeling and angiogenesis. This suggests that targeting LOX-1 may become a potential strategy for the treatment of diabetic osteoporosis.