Park So Yun, Choi Jun Young, Kim Rae Uk, Lee Young Sup, Cho Hee Jung, Kim Dong Sun
Department of Anatomy, School of Medicine, Kyungpook National University, Daegu 700-422, Korea.
Mol Cells. 2003 Oct 31;16(2):256-9.
Injury to peripheral nerves causes a neuropathic pain which is difficult to relieve, but the underlying mechanism remains largely unknown. In previous studies we reported that voltage-gated potassium (Kv) channel alpha genes are downregulated in the dorsal root ganglia (DRG) following chronic constriction of the sciatic nerve [Kim et al. (2002)], suggesting a relationship between electrical abnormalities of the injured neurons and Kv gene expression. Here, we examined expression of the Kv 1.2, 1.4, and 4.2 genes in the DRG following transection of the sciatic nerve, and investigated the effect of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) on expression of those mRNAs, using the reverse transcription-polymerase chain reaction. Expression of these mRNAs was reduced by axotomy and by exposure to BDNF, and NT-3 treatment. However no significant change was detected following NGF treatment. Our findings suggest that downregulation of Kv channel gene expression in DRG neurons by neurotrophins may play an important role in long-term changes of neuronal excitability following nerve injury.
外周神经损伤会导致难以缓解的神经性疼痛，但其潜在机制仍 largely 未知。在先前的研究中，我们报道了坐骨神经慢性缩窄后，背根神经节（DRG）中电压门控钾（Kv）通道α基因下调[Kim 等人（2002）]，这表明受损神经元的电异常与 Kv 基因表达之间存在关联。在此，我们检测了坐骨神经横断后 DRG 中 Kv 1.2、1.4 和 4.2 基因的表达，并使用逆转录-聚合酶链反应研究了神经生长因子（NGF）、脑源性神经营养因子（BDNF）和神经营养素-3（NT-3）对这些 mRNA 表达的影响。轴突切断术以及暴露于 BDNF 和 NT-3 处理后，这些 mRNA 的表达降低。然而，NGF 处理后未检测到显著变化。我们的研究结果表明，神经营养因子导致 DRG 神经元中 Kv 通道基因表达下调可能在神经损伤后神经元兴奋性的长期变化中起重要作用。
