Murine Kidney Tissue: Unilateral ureteral obstructed mice vs. Sham control

INTRODUCTION AND OBJECTIVE: Loss of renal function is often the impetus for operative intervention in renal obstruction. Obstructive nephropathy is characterized discrete morphological and physiologic changes including tubular dilatation, apoptosis, and atrophy, as well as interstitial cellular infiltration and progressive interstitial fibrosis. We hypothesize that there are gene expression alterations correlated with obstructive nephropathy that could serve as biomarkers for early intervention. METHODS: C57BL/6 mice were subjected to Unilateral Urethral Obstruction (UUO) or sham surgery at postnatal day 21 of life, and kidneys were harvested after 1, 2, 5 and 9 days postoperatively. RNA was extracted from kidneys and comprehensive gene expression profiling was performed with Agilent microarrays. We used biological replicates: 13 UUO replicates, 9 sham replicates. 2-Channel microarrays were hybridized using universal reference in the Cy3 channel. Ingenuity pathway analysis was used to analyze the biological function and gene networks of gene expression data. RESULTS: Microarray analysis revealed more than 1800 transcripts that were up- or down-regulated over days 1 through 9 following obstruction, and included many transcripts reported previously (FOS, CD44, CLU, SPP1 and EGF). Pathway analysis revealed significant enrichment of transcripts in cell activation/differentiation, immune/inflammatory responses, cell cycle, metabolic process and transport. Interestingly, IPA network analysis showed that transcriptional regulatory pathway involving CEBPB/HNF4A is involved in obstructive nephropathy. CONCLUSIONS: Transcript profiling identified numerous gene expression changes following UUO and suggests a role for CEBPB/HNF4A pathway in obstructive nephropathy. This dataset provides a foundation for development of biomarkers for obstructive nephropathy. Time: day samples were collected post operation Somatic Modification: mice were operated on to generate urethral obstruction (Obstructed/Control) time_series_design

引言与研究目的：
肾功能丧失往往是肾梗阻患者接受手术干预的核心动因。梗阻性肾病以一系列明确的形态学与生理学改变为特征，包括肾小管扩张、细胞凋亡、组织萎缩，以及间质细胞浸润和进行性间质纤维化。本研究假设存在与梗阻性肾病相关的基因表达改变，可作为早期干预的生物标志物。

研究方法：
选取出生后第21天的C57BL/6小鼠，分别实施单侧尿道梗阻（Unilateral Urethral Obstruction, UUO）手术与假手术，并于术后1、2、5、9天采集肾脏组织。从肾脏组织中提取RNA，采用安捷伦（Agilent）基因芯片开展全基因组表达谱分析。本研究设置生物学重复：UUO组13例，假手术组9例。采用Cy3通道搭载通用参照样本的方式完成双通道基因芯片杂交。使用Ingenuity通路分析（Ingenuity Pathway Analysis, IPA）对基因表达数据的生物学功能与基因调控网络进行分析。

研究结果：
基因芯片分析显示，梗阻发生后第1至9天内，共有超过1800个转录本出现上调或下调表达，其中包含此前已有报道的FOS、CD44、CLU、SPP1及EGF等转录本。通路分析显示，转录本显著富集于细胞活化/分化、免疫/炎症反应、细胞周期、代谢过程及物质转运等生物学过程。值得注意的是，IPA网络分析显示，涉及CEBPB/HNF4A的转录调控通路参与了梗阻性肾病的发生发展。

研究结论：
本研究通过转录组分析明确了UUO模型小鼠肾脏内的大量基因表达改变，并提示CEBPB/HNF4A通路在梗阻性肾病中发挥关键作用。本数据集可为梗阻性肾病生物标志物的开发提供重要基础。

采样时间：术后各时间点采集样本
实验修饰：通过手术构建尿道梗阻模型（梗阻组/对照组），采用时间序列实验设计