proBDNF inhibits the proliferation and migration of OLN-93 oligodendrocytes

In contrast with mature brain-derived neurotrophic factor (mBDNF), proBDNF induces cell apoptosis. However, the function of proBDNF in oligodendrocytes remains unclear. In the present study, the OLN-93 oligodendroglia cell line was utilized as an in vitro model to analyse the functions of proBDNF in oligodendroglia. p75NTR, sortilin and proBDNF were expressed in cultured OLN-93 cells. It was indicated that proBDNF inhibited OLN-93 cell proliferation in a dose-dependent manner as determined using the MTT assay and BrdU staining. Furthermore, proBDNF suppressed the migration of OLN-93 cells as demonstrated using the scratch assay. proBDNF also decreased cell viability and promoted apoptosis as indicated by activated cysteine-aspartic acid protease-3 (caspase-3) immunocytochemistry. Notably, anti-proBDNF treatment neutralized the effect of proBDNF and resulted in increased cell proliferation and migration and decreased apoptosis. However, these effects were not observed in the presence of recombinant p75NTR extracellular domain-human FC fusion protein and p75NTR antibody, indicating that proBDNF imparts its inhibitory effects on oligodendrocytes through the p75NTR signal pathway.