Semaphorin3A regulates mitochondrial apoptosis in RAW264.7 cells in vitro

Osteoclasts apoptosis plays vital roles in abnormal bone remodeling-associated diseases. It's reported that Semaphorin3A (Sema3A) may affect osteoarthritis progression through osteoclasts function, while the specific mechanism remains unclear. To determine the effect of Sema3A on osteoclasts, we detected the apoptosis of RAW264.7 cells treated with Sema3A and explored the potential pathways in vitro. Firstly, Cell Counting Kit-8 (CCK8) assay was performed to assess the proliferation to screen out the appropriate concentration of Sema3A. Then, apoptosis was evaluated after cells were incubated with Sema3A for 0, 2, 6, 12, 24 and 48 h, respectively, by Terminal Deoxynucleotidyl Transferase dUTP nick end labeling (TUNEL) staining and flow cytometry. Finally, phosphorylation of Nrf2 and CREB, mitochondrial apoptosis-related markers and JNK/AKT/ERK pathway activation were examined by qRT-PCR and Western blot. As a result, flow cytometry and TUNEL staining revealed that RAW264.7 cells apoptosis was promoted by Sema3A-treated. Meanwhile, Western blot showed that cleaved-caspase-3 and cleaved-caspase-9 were highly expressed in Sema3A-treated RAW264.7 cells, and the ERK/JNK/AKT pathways were significantly inhibited by Sema3A in RAW264.7 cells. In a word, we demonstrated that Sema3A induces apoptosis of RAW264.7 cells probably by promoting mitochondrial apoptosis, which may provide a potential target for therapeutic strategies.