Belluardo N, Wu G, Mudo G, Hansson A C, Pettersson R, Fuxe K
Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
J Comp Neurol. 1997 Mar 10;379(2):226-46.
The present study provides a detailed comparative description in the adult rat brain of areas that express mRNAs coding for the fibroblast growth factor subtype receptors 1-3 (FGFR1-3). One observation in this analysis was a widespread expression in the brain of all three FGFR mRNAs, according to the following rank order: FGFR1, diencephalon < telencephalon < mesencephalon and metencephalon < myelencephalon; FGFR2 and FGFR3, telencephalon < diencephalon < mesencephalon and metencephalon < myelencephalon. Another observation was an apparent cellular specificity in their basal expression. Thus, the FGFR1 mRNA was expressed mainly in large and weakly stained cells, whereas FGFR2 transcripts were expressed primarily in small and strongly stained cells and in cells of brain regions devoid of neuronal cells, such as the white matter. FGFR3 mRNA was always detected in small and strongly stained cells with scattered distribution and was not expressed in the white matter. However, FGFR2 mRNA was weakly expressed also in large cells localized in some nuclei of the lower brainstem, in the diagonal band, and in the septum. Furthermore, in the medial habenula and in the nuclei of the pons, there exists a high density of cells expressing both FGFR1 and FGFR2 (60-100%). With neurotoxic lesions involving 6-hydroxydopamine microinjections in the substantia nigra, reactive glial cells in the lesioned area and surrounding the cannula tract showed an increase in the expression of both FGFR1 and FGFR2 mRNAs, whereas no increased expression was found for FGFR3 mRNA. Taken together, these findings showed that these three FGF receptors exist in all subtypes of cells of each brain region. Their apparent cellular specificity suggests that these receptor subtypes can have a differential trophic role in the brain, reflecting the various biological activities shown by the ligands of the FGF family.
本研究对成年大鼠脑中表达成纤维细胞生长因子亚型受体1 - 3（FGFR1 - 3）编码mRNA的区域进行了详细的比较描述。该分析中的一个观察结果是，所有三种FGFR mRNA在脑中广泛表达，其表达水平按以下顺序排列：FGFR1，间脑＜端脑＜中脑和后脑＜延髓；FGFR2和FGFR3，端脑＜间脑＜中脑和后脑＜延髓。另一个观察结果是它们的基础表达具有明显的细胞特异性。因此，FGFR1 mRNA主要在大的、染色浅的细胞中表达，而FGFR2转录本主要在小的、染色深的细胞以及脑区中缺乏神经元细胞的区域（如白质）的细胞中表达。FGFR3 mRNA总是在小的、染色深的细胞中检测到，分布分散，且在白质中不表达。然而，FGFR2 mRNA在位于脑干下部某些核、斜角带和隔区的大细胞中也有弱表达。此外，在内侧缰核和脑桥核中，同时表达FGFR1和FGFR2的细胞密度很高（60 - 100%）。用6 - 羟基多巴胺微量注射到黑质造成神经毒性损伤后，损伤区域及套管周围的反应性胶质细胞中FGFR1和FGFR2 mRNA的表达均增加，而FGFR3 mRNA未发现表达增加。综上所述，这些发现表明这三种FGF受体存在于每个脑区的所有细胞亚型中。它们明显的细胞特异性表明这些受体亚型在脑中可能具有不同的营养作用，反映了FGF家族配体所显示的各种生物学活性。
