Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.
Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States.
Physiol Genomics. 2023 Nov 1;55(11):565-577. doi: 10.1152/physiolgenomics.00040.2023. Epub 2023 Sep 18.
Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in polycystin genes, and , but the underlying pathogenic mechanisms are poorly understood. To identify genes and pathways that operate downstream of polycystin-2 (PC2), a comprehensive gene expression database was created, cataloging changes in the transcriptome immediately following PC2 protein depletion. To explore cyst initiation processes, an immortalized mouse inner medullary collecting duct line was developed with the ability to knock out the gene conditionally. Genome-wide transcriptome profiling was performed using RNA sequencing in the cells immediately after PC2 was depleted and compared with isogenic control cells. Differentially expressed genes were identified, and a bioinformatic analysis pipeline was implemented. Altered expression of candidate cystogenic genes was validated in knockout mice. The expression of nearly 900 genes changed upon PC2 depletion. Differentially expressed genes were enriched for genes encoding components of the primary cilia, the canonical Wnt pathway, and MAPK signaling. Among the PC2-dependent ciliary genes, the transcription factor Glis3 was significantly downregulated. MAPK signaling formed a key node at the epicenter of PC2-dependent signaling networks. Activation of Wnt and MAPK signaling, concomitant with the downregulation of Glis3, was corroborated in knockout mice. The data identify a PC2 cilia-to-nucleus signaling axis and dysregulation of the Gli-similar subfamily of transcription factors as a potential initiator of cyst formation in ADPKD. The catalog of PC2-regulated genes should provide a valuable resource for future ADPKD research and new opportunities for drug development. Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease. Mutations in polycystin genes cause the disease, but the underlying mechanisms of cystogenesis are unknown. To help fill this knowledge gap, we created an inducible cell model of ADPKD and assembled a catalog of genes that respond in immediate proximity to polycystin-2 depletion using transcriptomic profiling. The catalog unveils a ciliary signaling-to-nucleus axis proximal to polycystin-2 dysfunction, highlighting Glis, Wnt, and MAPK signaling.
常染色体显性多囊肾病（ADPKD）是由多囊蛋白基因的突变引起的，但是其潜在的发病机制尚不清楚。为了确定多囊蛋白-2（PC2）下游作用的基因和途径，我们创建了一个全面的基因表达数据库，该数据库记录了 PC2 蛋白耗竭后转录组的即时变化。为了探索囊肿起始过程，我们开发了一种具有条件敲除 基因能力的永生化小鼠内髓集合管系。使用 RNA 测序在 PC2 耗竭后立即对细胞进行全基因组转录组谱分析，并与同基因对照细胞进行比较。识别差异表达基因，并实施生物信息学分析管道。在 基因敲除小鼠中验证候选囊肿基因的表达变化。PC2 耗竭后近 900 个基因的表达发生改变。差异表达基因富集了编码初级纤毛成分、经典 Wnt 途径和 MAPK 信号的基因。在 PC2 依赖性纤毛基因中，转录因子 Glis3 显著下调。MAPK 信号形成了 PC2 依赖性信号网络中心的关键节点。Wnt 和 MAPK 信号的激活，以及 Glis3 的下调，在 基因敲除小鼠中得到证实。数据确定了一个 PC2 纤毛到核的信号轴和 Gli 类似转录因子家族的失调作为 ADPKD 囊肿形成的潜在启动子。PC2 调节基因的目录应该为未来的 ADPKD 研究提供有价值的资源，并为药物开发提供新的机会。常染色体显性多囊肾病（ADPKD）是最常见的遗传性肾脏疾病。多囊蛋白基因的突变导致该疾病，但囊肿形成的潜在机制尚不清楚。为了帮助填补这一知识空白，我们创建了一个 ADPKD 的诱导细胞模型，并使用转录组谱分析组装了一个在靠近多囊蛋白-2 耗竭时响应的基因目录。该目录揭示了一个靠近多囊蛋白-2 功能障碍的纤毛信号到核的轴，突出了 Glis、Wnt 和 MAPK 信号。
