The experimental study of small ubiquitin-like modifier conjugation in mice spinal cord ischemia model

Abstract

Objective To determine whether spinal cord ischemia induces small ubiquitin-like modifier (SUMO) conjugation and to observe the subcelluar location of SUMO conjugation.Methods Activation of stress response pathways after spinal cord ischemia was verified by Western blotting analysis in mice spinal ischemia model.Levels and subcellular localizations of SUMO-conjugated proteins in spinal cords were evaluated by Western blotting analysis and immunol fluorescene staining,respectively.Results Following transient spinal cord ischemia,stress responses were activated as indicated by increased phosphorylation of eukaryotic initiation factor 2 (eIF2),extracellular signal-regulated kinase (ERK)1/2,and protein kinase B (Akt).Leves of SUMO1-conjugated proteins were not change significantly after 8,10,or 12 min ischemia,1.15 ±0.09,1.24 ± 0.13,1.01 ± 0.99,respectively (P ＞ 0.05).Levels of SUMO2/3conjugated proteins were markedly increased:5.87 ±0.31,5.40 ±0.36,4.31 ±0.28,respectively (P ＜0.01).The result of immunol fluorescene staining showed that SUMO2/3-conjugation proteins increased markedly and nulei accumulation occurred.Conclusion SUMO2/3 maybe a key molecular in internal neuroprotective pathway which played an important role in the stress response of spinal cord ischemia. Key words: Spinal cord ischemia injury; Small ubiquitin-like modifier; Neuroprotection