Proteomics reveals the key transcription-related factors mediating obstructive nephropathy in pediatric patients and mice

Obstructive nephropathy is one of the leading causes of kidney injury in infants and children. Increasing evidence has shown that transcription-related factors (TRFs), including transcription factors and cofactors, are associated with kidney diseases. However, a global landscape of dysregulated TRFs in pediatric patients with obstructive nephropathy is lacking. We mined the data from our previous proteomic study for the TRF profile in pediatric patients with obstructive nephropathy and unilateral ureteral obstruction (UUO) mice. Gene ontology (GO) analysis was performed to determine pathways that were enriched in the dysregulated TRFs. We then took advantage of kidney samples from patients and UUO mice to verify the selected TRFs by immunoblots. The proteomes identified a total of 140 human TRFs with 28 upregulated and 1 downregulated, and 160 murine TRFs with 88 upregulated and 1 downregulated (fold change >2 or <0.5). These dysregulated TRFs were enriched in the inflammatory signalings, such as janus kinase/signal transducer and activator of transcription (JAK-STAT) and tumor necrosis factor (TNF) pathways. Of note, the transforming growth factor (TGF)-β signaling pathway, which is the master regulator of organ fibrosis, was enriched in both patients and mice. Cross-species analysis showed 16 key TRFs that might mediate obstructive nephropathy in patients and UUO mice. Moreover, we verified a significant dysregulation of three previously unexplored TRFs; prohibitin (PHB), regulatory factor X 1 (RFX1), and activity-dependent neuroprotector homeobox protein (ADNP), in patients and mice. Our study uncovered key TRFs in the obstructed kidneys and provided additional molecular insights into obstructive nephropathy.

梗阻性肾病（obstructive nephropathy）是婴幼儿及儿童肾损伤的主要诱因之一。越来越多的研究证据表明，转录相关因子（transcription-related factors, TRFs）——包括转录因子及其辅因子——与肾脏疾病密切相关。然而，目前尚缺乏梗阻性肾病患儿体内失调转录相关因子的全局表达图谱。本研究从既往蛋白质组学研究的数据中挖掘了梗阻性肾病患儿及单侧输尿管梗阻（unilateral ureteral obstruction, UUO）模型小鼠体内的转录相关因子表达谱，通过基因本体论（Gene Ontology, GO）富集分析明确了失调转录相关因子所富集的信号通路。随后，本研究利用患儿及UUO模型小鼠的肾脏组织样本，通过免疫印迹实验对筛选出的转录相关因子进行了验证。蛋白质组学分析共鉴定出140个人类转录相关因子，其中28个表达上调、1个表达下调；同时鉴定出160个小鼠转录相关因子，其中88个表达上调、1个表达下调（折叠变化>2或<0.5）。上述失调的转录相关因子显著富集于炎症信号通路，例如贾纳斯激酶/信号转导与转录激活因子（janus kinase/signal transducer and activator of transcription, JAK-STAT）通路以及肿瘤坏死因子（tumor necrosis factor, TNF）通路。值得注意的是，作为器官纤维化核心调控因子的转化生长因子（transforming growth factor, TGF)-β信号通路，在患儿及模型小鼠样本中均呈现富集状态。跨物种分析显示，共有16个关键转录相关因子可能参与介导梗阻性肾病患儿与UUO模型小鼠的疾病进程。此外，本研究验证了3个此前未被探索的转录相关因子在患儿及模型小鼠体内的显著失调，分别为抑制素（prohibitin, PHB）、调控因子X 1（regulatory factor X 1, RFX1）以及活性依赖性神经保护同源盒蛋白（activity-dependent neuroprotector homeobox protein, ADNP）。本研究揭示了梗阻肾脏中的关键转录相关因子，为梗阻性肾病的发病机制提供了新的分子层面研究视角。