Siles Eva, Martínez-Lara Esther, Cañuelo Ana, Sánchez Marta, Hernández Raquel, López-Ramos Juan Carlos, Del Moral María Luisa, Esteban Francisco José, Blanco Santos, Pedrosa Juan Angel, Rodrigo José, Peinado María Angeles
Department of Experimental Biology, University of Jaén, Paraje Las Lagunillas s/n, E-23071, Jaén, Spain.
Brain Res. 2002 Nov 29;956(2):385-92. doi: 10.1016/s0006-8993(02)03575-8.
This work examines the age-related changes of the NO pathway in the central nervous system (CNS), analyzing nitric oxide synthase (NOS) isoform expression, the level of nitrotyrosine-modified proteins, and the NOS activity in the cerebral cortex, decorticated brain (basal ganglia, thalamus, hypothalamus, tegtum and tegmentum) and cerebellum of young, adult and aged rats. Our data demonstrate that the different NOS isoforms are not uniformly expressed across the CNS. In this sense, the nNOS and eNOS isoenzymes are expressed mainly in the cerebellum and decorticated brain, respectively, while the iNOS isoenzyme shows the highest level in cerebellum. Concerning age, in the cerebral cortex nNOS significantly increased its expression only in adult animals; meanwhile, in the cerebellum the eNOS expression decreased whereas iNOS increased in adult and aged rats. No age-related changes in any isoform were found in decorticated brain. NOS activity, determined by nitrate plus nitrite quantification, registered the highest levels in the cerebellum, where the significant increase detected with aging was probably related to iNOS activity. The number of nitrotyrosine-modified immunoreactive bands differed among regions; thus, the highest number was detected in the decorticated brain while the cerebellum showed the least number of bands. Finally, bulk protein nitration increased in cerebral cortex only in adult animal. No changes were found in the decorticated brain, and the decrease detected in the cerebellum of aged animals was not significant. According to these results, the NO pathway is differently modified with age in the three CNS regions analyzed.
这项研究检测了中枢神经系统(CNS)中与年龄相关的一氧化氮(NO)信号通路变化,分析了一氧化氮合酶(NOS)亚型的表达、硝基酪氨酸修饰蛋白的水平以及幼年、成年和老年大鼠大脑皮质、去皮质脑(基底神经节、丘脑、下丘脑、中脑被盖和脑桥被盖)和小脑中的NOS活性。我们的数据表明,不同的NOS亚型在整个中枢神经系统中的表达并不一致。从这个意义上说,nNOS和eNOS同工酶分别主要在小脑和去皮质脑中表达,而iNOS同工酶在小脑中表达水平最高。关于年龄,在大脑皮质中,nNOS仅在成年动物中显著增加其表达;同时,在小脑中,成年和老年大鼠的eNOS表达下降,而iNOS表达增加。在去皮质脑中未发现任何亚型与年龄相关的变化。通过硝酸盐加亚硝酸盐定量测定的NOS活性在小脑中最高,随着年龄增长检测到的显著增加可能与iNOS活性有关。硝基酪氨酸修饰的免疫反应条带数量在不同区域有所不同;因此,在去皮质脑中检测到的条带数量最多,而小脑显示的条带数量最少。最后,仅在成年动物的大脑皮质中检测到大量蛋白质硝化增加。在去皮质脑中未发现变化,在老年动物小脑中检测到的减少不显著。根据这些结果,在所分析的三个中枢神经系统区域中,NO信号通路随年龄的变化存在差异。