Dysregulated Transcription Factor TFAP2A After Peripheral Nerve Injury Modulated Schwann Cell Phenotype

Transcription factors regulate the transcriptions and expressions of numerous target genes and direct a variety of physiological and pathological activities. To obtain a better understanding of the involvement of transcription factors during peripheral nerve repair and regeneration, significantly differentially expressed genes coding for transcription factors in rat sciatic nerves after sciatic nerve crush injury were identified. A total of 9 transcription factor genes, including GBX2, HIF3A, IRF8, LRRC63, SNAI3, SPIB, TBX21, TFAP2A, and ZBTB16 were identified to be commonly differentially expressed at 1, 4, 7, and 14 days after nerve injury. TFAP2A, a gene encoding transcription factor activating enhancer binding protein 2 alpha, was found to be critical in the regulatory network. PCR validation and immunohistochemistry staining of injured rat sciatic nerves showed that TFAP2A expression was significantly up-regulated in the Schwann cells after nerve injury for at least 2 weeks. Schwann cells transfected with TFAP2A-siRNA exhibited elevated proliferation rate and migration ability, suggesting that TFAP2A suppressed Schwann cell proliferation and migration. Collectively, our study provided a global overview of the dynamic changes of transcription factors after sciatic nerve injury, discovered key transcription factors for the regeneration process, and deepened the understanding of the molecular mechanisms underlying peripheral nerve repair and regeneration.