Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, 226001, People's Republic of China.
Neurol Sci. 2012 Aug;33(4):749-57. doi: 10.1007/s10072-011-0809-8. Epub 2011 Sep 30.
p53-induced ring-H2 protein (PIRH2), a newly identified E3 ubiquitin ligase, has been reported to be interacted with p27Kip1 and promote ubiquitination of p27Kip1 independently of p53. p27kip1, a member of the Cip/Kip family of cyclin-dependent kinases inhibitors (CKIs), was shown to control cell cycle progression and promote cell proliferation. While the distribution and function of PIRH2 and p27kip1 in nervous system lesion and regeneration remains unclear. Here, we performed a sciatic nerve injury model in adult rats and studied the dynamic changes of PIRH2 and p27kip1 expression by western blot and RT-PCR in injured rat sciatic nerve. Sciatic nerve crush resulted in a significant up-regulation of PIRH2 and a down-regulation of p27kip1. Besides, we observed that they were expressed widely in both Schwann cells and axons in adult rat sciatic nerve by double immunofluorescence staining. Results obtained by coimmunoprecipitation and double labeling further showed their interaction in the regenerating process. Thus, these results indicate that PIRH2 and p27kip1 likely play an important role in peripheral nerve injury and regeneration.
p53 诱导的环指蛋白 2（PIRH2），一种新鉴定的 E3 泛素连接酶，已被报道与 p27kip1 相互作用，并独立于 p53 促进 p27kip1 的泛素化。p27kip1 是细胞周期蛋白依赖性激酶抑制剂（CKIs）家族的一员，被证明可以控制细胞周期进程并促进细胞增殖。然而，PIRH2 和 p27kip1 在神经系统损伤和再生中的分布和功能尚不清楚。在这里，我们在成年大鼠中进行了坐骨神经损伤模型，并通过 Western blot 和 RT-PCR 研究了损伤大鼠坐骨神经中 PIRH2 和 p27kip1 表达的动态变化。坐骨神经挤压导致 PIRH2 显著上调，p27kip1 下调。此外，我们通过双免疫荧光染色观察到它们在成年大鼠坐骨神经中的施万细胞和轴突中广泛表达。共免疫沉淀和双标记的结果进一步表明它们在再生过程中的相互作用。因此，这些结果表明 PIRH2 和 p27kip1 可能在外周神经损伤和再生中发挥重要作用。
