Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, People's Republic of China.
J Mol Histol. 2013 Feb;44(1):27-36. doi: 10.1007/s10735-012-9459-2. Epub 2012 Oct 18.
Gem belongs to the Rad/Gem/Kir subfamily of Ras-related GTPases, whose expression is induced in several cell types upon activation by extracellular stimuli. Two functions of Gem have been demonstrated, including regulation of voltage-gated calcium channel activity and inhibition of Rho kinase-mediated cytoskeletal reorganization, such as stress fiber formation and neurite retraction. Because of the essential relationship between actin reorganization and peripheral nerve regeneration, we investigated the spatiotemporal expression of Gem in a rat sciatic nerve crush (SNC) model. After never injury, we observed that Gem had a significant up-regulation from 1 day, peaked at day 5 and then gradually decreased to the normal level. At its peak expression, Gem expressed mainly in Schwann cells (SCs) and macrophages of the distal sciatic nerve segment, but had few colocalization in axons. In addition, the peak expression of Gem was in parallel with PCNA, and numerous SCs expressing Gem were PCNA positive. Thus, all of our findings suggested that Gem may be involved in the pathophysiology of sciatic nerve after SNC.
Gem 属于 Ras 相关 GTP 酶的 Rad/Gem/Kir 亚家族，其表达在外源刺激激活的几种细胞类型中被诱导。Gem 具有两种功能，包括调节电压门控钙通道活性和抑制 Rho 激酶介导的细胞骨架重排，如应力纤维形成和轴突回缩。由于肌动蛋白重排与周围神经再生之间存在重要关系，我们研究了 Gem 在大鼠坐骨神经挤压 (SNC) 模型中的时空表达。在神经损伤后，我们观察到 Gem 从第 1 天开始显著上调，在第 5 天达到峰值，然后逐渐降至正常水平。在其表达高峰时，Gem 主要在坐骨神经远端节段的施万细胞 (SCs) 和巨噬细胞中表达，但在轴突中很少有共定位。此外，Gem 的表达高峰与 PCNA 平行，大量表达 Gem 的SCs 为 PCNA 阳性。因此，我们的所有发现表明 Gem 可能参与 SNC 后坐骨神经的病理生理学过程。
