Charité Universitätsmedizin Berlin, Center for Anatomy, Institute of Cell Biology and Neurobiology, Berlin, Germany.
Biochem Biophys Res Commun. 2010 Dec 17;403(3-4):385-90. doi: 10.1016/j.bbrc.2010.10.138. Epub 2010 Nov 20.
Several reference genes have been used to quantify gene expression in human epilepsy surgery tissue. However, their reliability has not been validated in detail, although this is crucial in interpreting epilepsy-related changes of gene expression. We evaluated 12 potential reference genes in neocortical tissues resected from patients with temporal lobe epilepsy (TLE) with either few or many seizures (n=6 each) and post mortem controls (n=6) using geNorm and NormFinder algorithms. For all candidate reference genes threshold cycle (C(T)) values were measured. geNorm analysis revealed that the expression of e.g. glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) and hypoxanthine phosphoribosyl-transferase (HPRT) is unstable, whereas synaptophysin (SYP) and neuron-specific enolase (NSE)/mitochondrial 39S ribosomal protein L28 (MRPL) are most stably expressed. The geometric mean of SYP, NSE and MRPL levels is recommended as normalization factor (NF). NormFinder analysis, in contrast, indicated HPRT as the most stable single gene and recommended the geometric mean of TATA-box binding protein (TBP) and NSE levels as NF. Different values of upregulation of glial fibrillary protein (GFAP) expression were found in TLE tissue compared to control tissue depending on the NF used: 4.5-fold (geNorm-NF), 4.7-fold (NormFinder-NF), 4.2-fold (vs. GAPDH) and 7.8-fold (vs. HPRT). The expression of GABA(A) receptor subunit α5 (GARα5) was unaltered in the TLE groups compared to controls (geNorm-NF, NormFinder-NF, vs. GAPDH). However, normalization to HPRT suggests an apparent increase of GARα5 expression. In conclusion, the geNorm-NF (SYP/NSE/MRPL) and the NormFinder-NF (TBP/NSE) are equally suitable for normalization of gene expression in the human epileptogenic neocortex. In contrast, normalization to single and probably less stably expressed genes may not deliver accurate results.
已有几种参照基因被用于定量分析人类癫痫手术组织中的基因表达,但这些基因的可靠性尚未经过详细验证,而这对于解释与癫痫相关的基因表达变化至关重要。我们使用 geNorm 和 NormFinder 算法,评估了 12 种潜在的参照基因在颞叶癫痫(TLE)患者和尸检对照患者(每组 6 例)的新皮质组织中的表达情况,这些患者的癫痫发作次数较少或较多。所有候选参照基因的阈值循环(C(T))值均通过 geNorm 进行测量。geNorm 分析表明,例如甘油醛-3-磷酸脱氢酶(GAPDH)和次黄嘌呤磷酸核糖转移酶(HPRT)的表达不稳定,而突触小体相关蛋白(SYP)和神经元特异性烯醇化酶(NSE)/线粒体 39S 核糖体蛋白 L28(MRPL)的表达最稳定。建议使用 SYP、NSE 和 MRPL 水平的几何平均值作为标准化因子(NF)。相比之下,NormFinder 分析表明 HPRT 是最稳定的单一基因,并建议使用 TATA 框结合蛋白(TBP)和 NSE 水平的几何平均值作为 NF。根据所使用的 NF,在 TLE 组织与对照组织之间发现神经胶质纤维酸性蛋白(GFAP)表达的上调值不同:4.5 倍(geNorm-NF)、4.7 倍(NormFinder-NF)、4.2 倍(与 GAPDH 相比)和 7.8 倍(与 HPRT 相比)。与对照组相比,GABA(A)受体亚单位 α5(GARα5)在 TLE 组中的表达未改变(geNorm-NF、NormFinder-NF、与 GAPDH 相比)。然而,以 HPRT 为参照,GARα5 的表达似乎增加。总之,geNorm-NF(SYP/NSE/MRPL)和 NormFinder-NF(TBP/NSE)同样适用于人类致痫新皮质中的基因表达标准化。相比之下,以单个且可能表达不太稳定的基因进行标准化可能无法提供准确的结果。