Parrilla Marta, Lillo Concepción, Herrero-Turrion M Javier, Arévalo Rosario, Lara Juan Manuel, Aijón José, Velasco Almudena
Institute of Neuroscience of Castilla and León, Cell Biology, University of Salamanca, 37007 Salamanca, Spain.
Brain Res. 2009 Feb 19;1255:75-88. doi: 10.1016/j.brainres.2008.12.010. Epub 2008 Dec 11.
Pax2 is a well known transcription factor which participates in optic nerve development. It assures the correct arrival and package of the newly formed retinal axons and the adequate differentiation of the newly formed glial cells. Pax2 protein expression is continuous throughout adult life in the goldfish optic nerve. We have found two populations of astrocytes in the optic nerve: Pax2(+) and Pax2(-). Moreover, we have observed that the Pax2(+) astrocytes from the optic nerve head present differences in number and organization to those of the rest of the optic nerve. In the optic nerve head some Pax2(+) astrocytes, principally localized in the glia limitans, have thin GFAP(+) processes and weak cytokeratin and ZO1 immunolabeling. Several Pax2(+) astrocytes are in close association with the GFAP(+)/GS(+) Müller cell vitreal processes and with the growing Zn8(+) retinal ganglion cell axons. However, in the intraorbital segment, Pax2(+) astrocytes are more numerous and they have strongly cytokeratin(+)/ZO1(+) processes and form part of the reticular astrocytes and the glia limitans. We also found Pax2(-) astrocytes in both the optic nerve head and the intraorbital segment. In the intraorbital segment there are GS(+)/Pax2(-) cells which are absent from the optic nerve head. We propose that the maintenance of Pax2 protein expression in adult goldfish optic nerve could be related to the continuous addition of new ganglion cell axons and new glial cells.
Pax2是一种著名的转录因子，参与视神经发育。它确保新形成的视网膜轴突正确到达并包裹，以及新形成的神经胶质细胞充分分化。在成年金鱼的视神经中，Pax2蛋白表达持续存在。我们在视神经中发现了两类星形胶质细胞：Pax2(+)和Pax2(-)。此外，我们观察到来自视神经乳头的Pax2(+)星形胶质细胞在数量和组织上与视神经其余部分的星形胶质细胞存在差异。在视神经乳头，一些主要位于神经胶质界膜的Pax2(+)星形胶质细胞具有纤细的GFAP(+)突起，细胞角蛋白和ZO1免疫标记较弱。一些Pax2(+)星形胶质细胞与GFAP(+)/GS(+)米勒细胞的玻璃体突起以及生长中的Zn8(+)视网膜神经节细胞轴突紧密相关。然而，在眶内段，Pax2(+)星形胶质细胞数量更多，它们具有强烈的细胞角蛋白(+)/ZO1(+)突起，是网状星形胶质细胞和神经胶质界膜的一部分。我们在视神经乳头和眶内段都发现了Pax2(-)星形胶质细胞。在眶内段存在GS(+)/Pax2(-)细胞，而视神经乳头中没有这种细胞。我们认为成年金鱼视神经中Pax2蛋白表达的维持可能与新的神经节细胞轴突和新的神经胶质细胞的不断添加有关。
