Lucas F R, Salinas P C
Developmental Biology Research Centre, The Randall Institute, King's College London, 26-29 Drury Lane, London, WC2B 5RL, United Kingdom.
Dev Biol. 1997 Dec 1;192(1):31-44. doi: 10.1006/dbio.1997.8734.
WNT factors play a key role in early patterning of the embryo. However, expression of Wnt genes after cell commitment suggests additional roles in later developmental processes. We report here that Wnt-7a is expressed in cerebellar granule cell neurons as they begin to extend processes and form synapses. WNT-7a increases axonal spreading and branching in cultured granule cells. Moreover, WNT-7a increases the levels of synapsin I, a presynaptic protein involved in synapse formation and function. Lithium mimics WNT-7a in granule cells by inhibiting GSK-3beta, a component of the WNT signaling pathway. These results suggest a direct effect of WNT-7a in the regulation of neuronal cytoskeleton and synapsin I in granule cell neurons. We propose that WNT proteins have a novel function in the formation of neuronal connections.
WNT因子在胚胎早期模式形成中起关键作用。然而，细胞定型后Wnt基因的表达表明其在后期发育过程中还有其他作用。我们在此报告，Wnt-7a在小脑颗粒细胞神经元开始延伸突起并形成突触时表达。WNT-7a增加培养的颗粒细胞中轴突的伸展和分支。此外，WNT-7a增加突触素I的水平，突触素I是一种参与突触形成和功能的突触前蛋白。锂通过抑制WNT信号通路的组成部分GSK-3β在颗粒细胞中模拟WNT-7a。这些结果表明WNT-7a对颗粒细胞神经元中神经元细胞骨架和突触素I的调节有直接作用。我们提出WNT蛋白在神经元连接形成中具有新功能。
