Peretto P, Dati C, De Marchis S, Kim H H, Ukhanova M, Fasolo A, Margolis F L
Department of Human and Animal Biology, University of Torino, 10123 Torino, Italy.
Neuroscience. 2004;128(4):685-96. doi: 10.1016/j.neuroscience.2004.06.053.
The antagonism between noggin and the bone morphogenetic proteins (BMPs) plays a key role during CNS morphogenesis and differentiation. Recent studies indicate that these secreted factors are also widely expressed in the postnatal and adult mammalian brain in areas characterized by different types of neural plasticity. In particular, significant levels of noggin and BMP expression have been described in the rodent olfactory system. In the mammalian forebrain, the olfactory bulb (OB) and associated subependymal layer (SEL) are documented as sites of adult neurogenesis. Here, using multiple approaches, including the analysis of noggin-LacZ heterozygous mice, we report the expression of noggin and two members of the BMP family, BMP4 and BMP7, in these regions of the adult mammalian forebrain. We observe that along the full extent of the SEL, from the lateral ventricle to the olfactory bulb, noggin and BMP4 and 7 are mainly associated with the astrocytic glial compartment. In the OB, BMP4 and 7 proteins remain primarily associated with the SEL while strong noggin expression was also found in cells located in different OB layers (i.e. granule, external plexiform, glomerular layers). Taken together our data lead us to hypothesize that within the SEL the antagonism between noggin and BMPs, both produced by the glial tubes, act through autocrine/paracrine inductive mechanisms to maintain a neurogenetic environment all the way from the lateral ventricle to the olfactory bulb. In the OB, their expression patterns suggest multiple regulatory roles on the unusual neural plasticity exhibited by this region.
头蛋白与骨形态发生蛋白（BMPs）之间的拮抗作用在中枢神经系统形态发生和分化过程中起关键作用。最近的研究表明，这些分泌因子在出生后及成年哺乳动物大脑中以不同类型神经可塑性为特征的区域也广泛表达。特别是，在啮齿动物嗅觉系统中已描述到头蛋白和BMP有显著水平的表达。在哺乳动物前脑，嗅球（OB）和相关的室管膜下层（SEL）被记录为成体神经发生的部位。在此，我们使用多种方法，包括对头蛋白-LacZ杂合小鼠的分析，报告了头蛋白以及BMP家族的两个成员BMP4和BMP7在成年哺乳动物前脑这些区域的表达。我们观察到，沿着SEL的全长，从侧脑室到嗅球，头蛋白以及BMP4和7主要与星形胶质细胞区室相关。在嗅球中，BMP4和7蛋白主要仍与SEL相关，而在位于嗅球不同层（即颗粒层、外丛状层、肾小球层）的细胞中也发现了强头蛋白表达。综合我们的数据，使我们推测在SEL内，由胶质管产生的头蛋白和BMPs之间的拮抗作用通过自分泌/旁分泌诱导机制起作用，以维持从侧脑室到嗅球全程的神经发生环境。在嗅球中，它们的表达模式表明对该区域所展现的异常神经可塑性具有多种调节作用。
