Roles of a newly identified TNF receptor superfamily, TROY, in the nervous system

(1) TROT在发育和成年小鼠中枢神经系统中的表达和作用我们对发育和成年小鼠中枢神经系统中表达TROT的细胞及其在神经发育中的作用进行了表征。在胚胎阶段，TROY在神经上皮细胞和放射状胶质细胞中高度表达。在出生后和成人期，TROY在含有神经干细胞的心室下区（SVZ）表达。双免疫荧光染色显示，出生后SVZ中表达TROY的细胞Musashi-1阳性，PSA-NCAM阴性，表明TROY在未交或胶质前体细胞中表达，而在神经元前体细胞中不表达。此外，TROY在成人SVZ中也有表达。在成人SVZ中，GFAP阳性细胞和EGFR阳性细胞中的一部分是神经干细胞，它们产生TuJ1和psa - ncam阳性的神经前体细胞，TROY、GFAP和EGFR的三重免疫荧光染色显示，所有表达TROY的细胞都表达GFAP或EGFR。此外，TROY在出生后和成年前脑的星形胶质系细胞中表达，而在整个发育过程中，tuj1阳性的神经元前体细胞和neun阳性的神经元中未观察到TROY的表达，因此，TROY在神经上皮-放射状胶质-星形胶质系细胞中表达，这可能是一个默认的谱系。PC12细胞中TROY的过表达抑制ngf诱导的神经突生长，并下调神经元分化标志物。这些发现表明TROY可能通过抑制发育和成年中枢神经系统的神经元分化参与维持默认谱系。(2) TROY在发育中的嗅觉系统表达在胚胎后期和成体阶段，TROY mRNA和蛋白的表达在嗅神经层（ONL-i）内侧最为明显。双免疫荧光法显示，在ONL-i中表达TROY的细胞对神经肽Y有免疫反应，但对S-100和p75低亲和神经生长因子受体无免疫反应，表明TROY在ONL-i的oec中有表达，而在ONL-i外部的oec （ONL-o）中无表达。此外，随着出生后发育从新生儿期到成年期，肾小球层（GL）中troy表达细胞呈由浅层向深层逐渐增加的趋势。这些细胞被GFAP染色，但未被NPY染色，可能是星形细胞样的oec。此外，成年小鼠ONL-i中的一些troy阳性细胞也是gfap阳性，npy阴性的胶质细胞。因此，TROY阳性的oec可能具有共同的谱系，并在发育过程中受到环境影响而改变其表型，这表明TROY在嗅觉系统的发育和可塑性中发挥了一定的作用。少

(1)Expression and roles of TROT in the developing and adult CNSWe characterized TROY-expressing cells in the developing and adult mouse CNS, and their roles in the neural development. TROY was highly expressed in neuroepithelial cells and radial glial cells during embryonic stages. During postnatal and adult stages, TROY was expressed in the subventricular zone (SVZ), which is known to contain neural stem cells. Double-immunofluorescent staining showed that TROY-expressing cells in the postnatal SVZ were positive for Musashi-1 and negative for PSA-NCAM, indicating that TROY is expressed in uncommitted or glial precursor cells, but not in neuronal precursor cells. In addition, TROY was also expressed in the adult SVZ. In the adult SVZ, a subset of GFAP-positive cells and EGFR-positive cells are neural stem cells, which generate TuJ1- and PSA-NCAM-positive neuronal precursor cells, Triple-immunofluorescent staining for TROY,GFAP, and EGFR revealed that all TROY-expressing cells expressed … More either GFAP or EGFR. Furthermore, TROY was expressed in astroglial lineage cells in the postnatal and adult forebrain, whereas expression of TROY was not observed in TuJ1-positive neuronal precursor cells and NeuN-positive neurons throughout development, Thus, TROY was expressed in neuroepithelial-radial glia-astrocyte lineage cells, which may be in a default lineage. Overexpression of TROY in PC12 cells inhibited NGF-induced neurite outgrowth and down-regulated neuronal differentiation markers. These findings indicate that TROY may be involved in maintaining a default lineage by repressing neuronal differentiation in the developing and adult CNS.(2)Expression of TROY in the developing olfactory systemDuring late embryonic and adult stages, expression of TROY mRNA and proteins was most evident in the inner part of the olfactory nerve layer (ONL-i). Double-immunofluorscence method showed that TROY-expressing cells in the ONL-i were immunoreactive for neuropeptide Y, but not for S-100 or p75 low affinity nerve growth factor receptor, indicating that TROY is expressed in OECs of the ONL-i, but not in OECs of the outer part of the ONL (ONL-o). In addition, TROY-expressing cells were gradually increased in the glomerula layer (GL) with direction from superficial to deeper layers as postnatal development proceeded from neonatal stage to adulthood. These cells stained for GFAP but not for NPY, may be astrocyte-like OECs. Moreover, some TROY-positive cells in the ONL-i of adult mice were also GFAP-positive, NPY-negative glial cells. Therefore, TROY-positive OECs may share a common lineage and alter their phenotypes by environmental influences during the development, suggesting that TROY plays some roles in the development and plasticity of the olfactory system. Less