Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, 713-8 Kamiya, Kasugai, 480-0392, Japan.
Department of Neurochemistry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Nagoya, 466-8550, Japan.
Med Mol Morphol. 2021 Jun;54(2):146-155. doi: 10.1007/s00795-020-00275-1. Epub 2021 Jan 25.
Abnormalities of PLEKHG2 gene, encoding a Rho family-specific guanine nucleotide exchange factor, are involved in microcephaly with intellectual disability. However, not only the role of PLEKHG2 in the developmental process but also its expression profile is unknown. In this study, we prepared a specific antibody against PLEKHG2 and carried out expression analyses with mouse tissues. In western blotting, PLEKHG2 exhibited a tissue-dependent expression profile in adult mouse and was expressed in a developmental stage-dependent manner in brain. Then, in immunohistochemical analyses, while PLEKHG2 was observed in the cortical plate and ventricular zone surface of the cerebral cortex at embryonic day 14, it came to be distributed throughout the cerebral cortex in layer II/III and V during corticogenesis. PLEKHG2 was also detected mainly in the nucleus of neurons in the hippocampal CA regions and dentate gyrus at P7. Notably, the nuclear accumulation disappeared at P30 and PLEKHG2 came to be located at the axons and/or dendrites at this time point. Moreover, in vitro immunofluorescence revealed that PLEKHG2 was at least partially localized at both excitatory and inhibitory synapses in primary cultured hippocampal neurons. These results suggest roles of PLEKHG2 in the development of the central nervous tissue and synaptic function.
PLEKHG2 基因异常，编码 Rho 家族特异性鸟嘌呤核苷酸交换因子，与小头畸形伴智力障碍有关。然而，PLEKHG2 不仅在发育过程中的作用未知，其表达谱也未知。在这项研究中，我们制备了针对 PLEKHG2 的特异性抗体，并对小鼠组织进行了表达分析。在 Western blot 中，PLEKHG2 在成年小鼠中表现出组织依赖性表达谱，并在大脑中表现出发育阶段依赖性表达。然后，在免疫组织化学分析中，虽然在胚胎 14 天的大脑皮层中观察到 PLEKHG2 在皮质板和脑室区表面表达，但在皮质发生过程中，它分布在 II/III 层和 V 层中。在 P7 时，PLEKHG2 也主要在海马 CA 区和齿状回的神经元核中检测到。值得注意的是，核积累在 P30 时消失，此时 PLEKHG2 位于轴突和/或树突上。此外，体外免疫荧光显示 PLEKHG2 至少部分定位于原代培养海马神经元中的兴奋性和抑制性突触上。这些结果表明 PLEKHG2 在中枢组织发育和突触功能中发挥作用。
