Centro de Investigación en Encefalopatías y Enfermedades Transmisibles Emergentes, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain.
BMC Genomics. 2012 Aug 16;13:399. doi: 10.1186/1471-2164-13-399.
The pathogenesis of natural scrapie and other prion diseases is still poorly understood. Determining the variations in the transcriptome in the early phases of the disease might clarify some of the molecular mechanisms of the prion-induced pathology and allow for the development of new biomarkers for diagnosis and therapy. This study is the first to focus on the identification of genes regulated during the preclinical phases of natural scrapie in the ovine medulla oblongata (MO) and the association of these genes with prion deposition, astrocytosis and spongiosis.
A custom microarray platform revealed that 86 significant probes had expression changes greater than 2-fold. From these probes, we identified 32 genes with known function; the highest number of regulated genes was included in the phosphoprotein-encoding group. Genes encoding extracellular marker proteins and those involved in the immune response and apoptosis were also differentially expressed. In addition, we investigated the relationship between the gene expression profiles and the appearance of the main scrapie-associated brain lesions. Quantitative Real-time PCR was used to validate the expression of some of the regulated genes, thus showing the reliability of the microarray hybridization technology.
Genes involved in protein and metal binding and oxidoreductase activity were associated with prion deposition. The expression of glial fibrillary acidic protein (GFAP) was associated with changes in the expression of genes encoding proteins with oxidoreductase and phosphatase activity, and the expression of spongiosis was related to genes encoding extracellular matrix components or transmembrane transporters. This is the first genome-wide expression study performed in naturally infected sheep with preclinical scrapie. As in previous studies, our findings confirm the close relationship between scrapie and other neurodegenerative diseases.
天然瘙痒病和其他朊病毒病的发病机制仍不清楚。确定疾病早期转录组的变化可能阐明朊病毒诱导病理学的一些分子机制，并为诊断和治疗开发新的生物标志物。本研究首次专注于鉴定在绵羊延髓（MO）天然瘙痒病临床前阶段调节的基因，以及这些基因与朊病毒沉积、星形胶质细胞增生和海绵状变性的关联。
定制的微阵列平台显示，有 86 个显著探针的表达变化大于 2 倍。从这些探针中，我们确定了 32 个具有已知功能的基因；调节基因数量最多的是磷酸蛋白编码组。编码细胞外标记蛋白以及参与免疫反应和细胞凋亡的基因也表现出差异表达。此外，我们还研究了基因表达谱与主要瘙痒相关脑病变出现之间的关系。使用定量实时 PCR 验证了一些调节基因的表达，从而显示了微阵列杂交技术的可靠性。
涉及蛋白质和金属结合以及氧化还原酶活性的基因与朊病毒沉积有关。胶质纤维酸性蛋白 (GFAP) 的表达与编码具有氧化还原酶和磷酸酶活性的蛋白质的基因表达变化有关，而海绵状变性的表达与编码细胞外基质成分或跨膜转运蛋白的基因有关。这是在具有临床前瘙痒病的自然感染绵羊中进行的首次全基因组表达研究。与之前的研究一样，我们的发现证实了瘙痒病与其他神经退行性疾病之间的密切关系。
