SOCS3 Attenuates GM-CSF/IFN-r-Mediated Inflammation During Spontaneous Spinal Cord Regeneration
1 Key laboratory of Neuroregeneration of Jiangsu and The Ministry of Education, Nantong University, Nantong 226001, China
2 Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
3 Department of Rehabilitation Medicine, Affiliated Hospital of Nantong University, Nantong 226001, China
Abstract
SOCS3, a feedback inhibitor of the JAK/STAT signal pathway, negatively regulates axonal regrowth and inflammation in the central nervous system (CNS). Here, we demonstrated a distinct role of SOCS3 in the injured spinal cord of the gecko following tail amputation. Severing the gecko spinal cord did not evoke an inflammatory cascade except for an injury-stimulated elevation of the granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon gamma (IFN-γ) cytokines. Simultaneously, the expression of SOCS3 was upregulated in microglia, and unexpectedly not in neurons. Enforced expression of SOCS3 was sufficient to suppress the GM-CSF/IFN-γ-driven inflammatory responses through its KIR domain by attenuating the activities of JAK1 and JAK2. SOCS3 was also linked to GM-CSF/IFN-γ-induced cross-tolerance. Transfection of adenovirus overexpressing SOCS3 in the injured cord resulted in a significant decrease of inflammatory cytokines. These results reveal a distinct role of SOCS3 in the regenerating spinal cord, and provide new hints for CNS repair in mammals.
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