Altered expression of glycoprotein non-metastatic melanoma protein B in the distal sciatic nerve following injury

Glycoprotein non-metastatic melanoma protein B (GPNMB) exerts neuroprotective effects on amyotrophic lateral sclerosis and cerebral ischemia reperfusion injury in the central nervous system. However, the expression and function of GPNMB in the peripheral nervous system, particularly following peripheral nerve injury, remains unknown. In the present study, the mRNAs and long non-coding RNAs of the distal sciatic nerve were profiled via microarray analysis at days 0, 1, 3, 7, 14, 21 and 28 following transection. The results revealed that the expression of GPNMB mRNA was similar to the proliferation tendency of distal acute denervated Schwann cells (SCs), the results of which were further validated by reverse transcription quantitative polymerase chain reaction, western blot analysis and immunohistochemistry. To investigate the function of GPNMB on SCs, recombinant human GPNMB (rhGPNMB) was added to cultured denervated SCs from the distal stumps of transected sciatic nerve. The proliferation, expression and secretion of neurotrophic factors (NTFs) and neural adhesion molecules (NAMs) were subsequently detected. The results demonstrated that GPNMB expression was increased in distal sciatic nerve following transection in vivo, while rhGPNMB promoted the proliferation of SCs as well as expression and secretion of NTFs and NAMs in vitro. Therefore, GPNMB could be a novel strategy for peripheral nerve regeneration.