Noggin在大鼠中枢神经系统发育过程中的表达

EXPRESSION OF Noggin IN CNS NEURONS OF THE DEVELOPING RAT

目的 研究Noggin基因在大鼠中枢神经系统 (CNS)发育过程中的表达。 方法 地高辛标记的cRNA探针原位杂交组织化学技术。 结果 ISHH结果显示 ,在胚胎期 (E16 )大鼠 ,nogginmRNA阳性细胞主要位于大脑皮质、海马、丘脑与下丘脑的部分核团。新生期 (P1～P2 )大鼠 ,noggin在大脑皮质与海马的表达均降低 ,而在丘脑与延脑的表达增强 ;生后 1周 (P1W )noggin在脑内的表达明显降低 ,生后 2周noggin在脑内的表达开始升高 ,在大脑皮质与海马升高尤为明显。生后 1个月 ,noggin表达继续升高 ,在额叶皮质、顶叶皮质、扣带皮质、梨状皮质及海马的齿状回可检测到强阳性信号 ;而在丘脑的侧核、网状核、腹内侧核与腹外侧核可见中等强度的阳性信号。此外 ,在下丘脑的室旁核和视上核亦可见密集深染的阳性神经元。生后 3个月 ,noggin阳性细胞在脑内的表达开始降低 ;生后 18个月 ,noggin表达降至最低 ,仅见散在的阳性神经元。此外 ,在不同发育期大鼠的脊髓亦未观察到nogginmRNA阳性细胞。

Objective To examine the expression of Noggin in CNS of the developing rat. Methods In situ hybridization histochemistry(ISHH) was performed using digoxigenin-labeled cRNA as probes. Results It was revealed that densely and deeply stained noggin positive cells were detected in cortex,hippocampus,cerebellum,and nucleus of hypothalamus and thalamus in embryonic day(E)16 rats.The number of noggin positive cells was increased in the thalamus and medulla oblongata at postnatal day(P)1-2,whereas decreased in the hippocampus and cortex.The number of noggin positive cells was decreased significantly in brain at 1 week postnatal(P1W),and began to increase at P2W,especially in the cortex and hippocamps.Strong positive signal can be detected in the frontal cortex,parietal cortex,cingulated cortex,hippocampus,olfactory and cerebellum at 1 month postnatal(P1M).The expression of noggin begins to decline at P3M,only sparse noggin positive cells can be seen in CNS at P18M.Furthermore,there is no noggin positive cells seen in the spinal cord of rats during development.Conclusion Our results indicated that noggin could play an important role in CNS development of rats.