D'Souza Mary, Zhu Xiaoxia, Frisina Robert D
Department of Otolaryngology, University of Rochester School of Medicine & Dentistry, 601 Elmwood Avenue, Rochester, NY 14642-8629, USA.
J Neurosci Methods. 2008 Jun 30;171(2):279-87. doi: 10.1016/j.jneumeth.2008.02.022. Epub 2008 Mar 27.
Presbycusis - age-related hearing loss - is the number one communicative disorder and one of the top three chronic medical condition of our aged population. High-throughput technologies potentially can be used to identify differentially expressed genes that may be better diagnostic and therapeutic targets for sensory and neural disorders. Here we analyzed gene expression for a set of GABA receptors in the cochlea of aging CBA mice using the Affymetrix GeneChip MOE430A. Functional phenotypic hearing measures were made, including auditory brainstem response (ABR) thresholds and distortion-product otoacoustic emission (DPOAE) amplitudes (four age groups). Four specific criteria were used to assess gene expression changes from RMA normalized microarray data (40 replicates). Linear regression models were used to fit the neurophysiological hearing measurements to probe-set expression profiles. These data were first subjected to one-way ANOVA, and then linear regression was performed. In addition, the log signal ratio was converted to fold change, and selected gene expression changes were confirmed by relative real-time PCR.
expression of GABA-A receptor subunit alpha6 was upregulated with age and hearing loss, whereas subunit alpha1 was repressed. In addition, GABA-A receptor associated protein like-1 and GABA-A receptor associated protein like-2 were strongly downregulated with age and hearing impairment. Lastly, gene expression measures were correlated with pathway/network relationships relevant to the inner ear using Pathway Architect, to identify key pathways consistent with the gene expression changes observed.
老年性聋——与年龄相关的听力损失——是头号交流障碍，也是老年人群三大慢性疾病之一。高通量技术有可能用于识别差异表达基因，这些基因可能成为感觉和神经障碍更好的诊断和治疗靶点。在此，我们使用Affymetrix GeneChip MOE430A分析了衰老CBA小鼠耳蜗中一组GABA受体的基因表达。进行了功能性表型听力测量，包括听觉脑干反应（ABR）阈值和畸变产物耳声发射（DPOAE）振幅（四个年龄组）。使用四个特定标准评估来自RMA标准化微阵列数据（40次重复）的基因表达变化。使用线性回归模型将神经生理学听力测量值与探针集表达谱进行拟合。这些数据首先进行单因素方差分析，然后进行线性回归。此外，将对数信号比转换为倍数变化，并通过相对实时PCR确认选定的基因表达变化。
GABA-A受体亚基α6的表达随年龄和听力损失而上调，而亚基α1则受到抑制。此外，GABA-A受体相关蛋白样-1和GABA-A受体相关蛋白样-2随年龄和听力损害而强烈下调。最后，使用Pathway Architect将基因表达测量值与内耳相关的通路/网络关系进行关联，以识别与观察到的基因表达变化一致的关键通路。
