内质网分子伴侣GRP78在小鼠脑发育过程中的时空表达

多细胞生物体发育的实质是基因的选择性表达,表达蛋白的成熟有赖于分子伴侣的协助,但迄今分子伴侣特别是内质网分子伴侣在脑发育过程中的作用尚不清楚。本文应用RT-PCR、蛋白质免疫印迹和免疫组织化学的方法研究了小鼠发育不同阶段的脑组织中GRP78的表达和定位分布随时间变化的情况。结果发现GRP78在小鼠脑发育过程中呈时空性表达:胚胎早期表达较高,胚胎发育末期逐渐下降,出生后逐渐升高,至生后一周时达到成年鼠的水平;在胚胎期GRP78蛋白在脑组织的表达呈现从端脑到后脑逐渐降低的趋势。研究结果还表明GRP78蛋白的免疫染色阳性产物在神经细胞中出现的时间早于神经胶质细胞。这些首次观察到的结果提示GRP78与脑的早期发生和形态建成有一定的关系。

THE EXPRESSION OF GLUCOSE-REGULATED PROTEIN 78(GRP78) IN MOUSE BRAIN DURING EARLY DEVELOPMENT

The development of a multicellular organism results from the selective expression of genes and the maturation of proteins is dependent on molecular chaperons. However, the functions of molecular chaper-ones, especially endoplasmic reticulum chaperones, on brain development are unclear. In this article we examined the distribution and level of GRP78 in mouse brain during early development by means of Western blot, RT- PCR and immunohistochemisty. The results demonstrated that the expression of GRP78 was in a time-space specific pattern. High levels of GRP78 were present in early embryo stage, and were decreased during the fetal period, increased gradually during postnatal development, and reached adult mouse after one week. In addition, the expression of GPR78 displayed the levels in tendency to decrease from telencephalon to meten-cephalon during embryonic period. The distribution for GRP78 appeared to be present earlier in neurons than in glial cells. These results suggested that GRP78 might play a significant role in the early morphogenesis of brain.