Searching for differentially expressed proteins in spinal cord injury based on the proteomics analysis

Aims: We aimed to identify potential differentially expressed proteins that play roles in the spinal cord injury. Materials and methods: The mouse model of spinal cord injury was firstly built, followed by grip strength evaluation. Then, isobaric tags for relative and absolute quantization (iTRAQ) analysis was used to identify differentially expressed proteins at 1, 2, 3 and 8 weeks after spinal cord injury. Finally, analysis of spinal cord injury repair related differentially expressed proteins in the early and middle-late stage of injury was performed followed by the functional analysis. Key findings: The result of grip strength evaluation showed that the motor function of the forelimbs of the mouse was significantly impaired after spinal cord injury. In the iTRAQ analysis, a total of 29 common differentially expressed proteins (such as Hbb-bs, Hba, S100a6, Ca1, Apoa4, Hspb1, Hist1h1c, Hist1h1e, Hbb-b1, Apoa1 and S100a10) were obtained at 1, 2, 3 and 8 weeks after spinal cord injury. A total of 70 and 180 common differentially expressed proteins were identified in the early and middle-late stage of injury, respectively. PPAR signaling pathway (involved Apoa1) and VEGF signaling pathway (involved Hspb1) were identified in the middle-late stage of spinal cord injury repair. Significance: Identified differentially expressed proteins and related signaling pathways may be associated with spinal cord injury.