Effects of precursor of brain-derived neurotrophic factor on the survival and growth of oligodendrocytes after spinal cord injury

Abstract

Objective To investigate whether the precursor of Brain-drived neurotrophic factor (proBDNF) can be expressed on oligodenerocyte precursor cells (OPCs) and the effects of proBDNF on the survival and growth of OPCs in the acute period of spinal cord injury (SCI).Methods Primary cuhure of OPCs from neonatal C57BL/6 mice was applied for the studies.Western blotting was used to investigate the expression levels of proBDNF and its receptors p75NTR and sortilin in OPCs.100 μg/L bovine serum albumin (BSA) was used as a control group and gradient concentrations of proBDNF (1,10,100 μg/L) were used to treat the cells.Each group had 6 wells of cultured cells.After the treatment,crystal violet staining and β-tublin immunofluorescence staining were used to observe the size and growth of cells.Results Western blotting showed that proBDNF,p75NTR and sortilin were endogeneously expressed on OPCs.As compared with the BSA control,proBDNF inhibited survival of OPCs (537.67 ± 34.93 vs.440.67 ± 9.29,390.67 ± 9.45 and 337.25 ± 7.27) and the difference was statistically significant (P ＜ 0.001).Meanwhile,proBDNF also inhibited the OPCs growth as compared with BSA group.The OPCs in proBDNF treated groups had less long projections and smaller size [(2.44 ± 0.71) vs.(1.65 ± 0.10),(1.30 ± 0.11) and (0.95 ± 0.08) μm2].The difference was statistically significant (P ＜ 0.05 in 1 μg/L proBDNF group,and P ＜ 0.01 in other groups).Conclusion OPCs express proBDNF and its receptors endogenously.proBDNF can inhibit the survival and growth of OPCs and the inhibitory effects may be induced by p75NTR-sortilin pathway. Key words: Precursor of brain-derived neurotrophic factor; Oligodenerocyte precursor cells; Spinal cord injnury