Abstract:
Hepatocyte nuclear factor 1B (HNF1B) encodes a transcription factor expressed in developing human kidney epithelia. Heterozygous HNF1B mutations are the commonest monogenic cause of dysplastic kidney malformations (DKMs). To understand their pathobiology, we generated heterozygous HNF1B mutant kidney organoids from CRISPR-Cas9 gene-edited human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) reprogrammed from a family with HNF1B-associated DKMs. Mutant organoids contained enlarged malformed tubules displaying deregulated cell turnover. Numerous genes implicated in Mendelian kidney tubulopathies were downregulated, and mutant tubules resisted the cyclic AMP (cAMP)-mediated dilatation seen in controls. Bulk and single-cell RNA sequencing (scRNA-seq) analyses indicated abnormal Wingless/Integrated (WNT), calcium, and glutamatergic pathways, the latter hitherto unstudied in developing kidneys. Glutamate ionotropic receptor kainate type subunit 3 (GRIK3) was upregulated in malformed mutant nephron tubules and prominent in HNF1B mutant fetal human dysplastic kidney epithelia. These results reveal morphological, molecular, and physiological roles for HNF1B in human kidney tubule differentiation and morphogenesis illuminating the developmental origin of mutant-HNF1B-causing kidney disease.
摘要:
肝细胞核因子1B(HNF1B)编码在发育中的人肾上皮中表达的转录因子。杂合HNF1B突变是发育不良肾脏畸形(DKM)的最常见的单基因原因。为了了解他们的病理学,我们从CRISPR-Cas9基因编辑的人胚胎干细胞(ESCs)和从HNF1B相关DKM家族重编程的诱导多能干细胞(iPSCs)中产生了杂合的HNF1B突变肾脏器官。许多与孟德尔肾小管病变有关的基因被下调,突变小管抵抗了对照中可见的环AMP(cAMP)介导的扩张。大量和单细胞RNA测序(scRNA-seq)分析显示异常无翼/整合(WNT),钙,和谷氨酸能途径,后者迄今为止在发展肾脏方面尚未研究。谷氨酸离子型受体红藻氨酸3型亚基(GRIK3)在畸形突变的肾单位小管中上调,在HNF1B突变的胎儿人类发育不良肾上皮中突出。这些结果揭示了形态学,分子,以及HNF1B在人肾小管分化和形态发生中的生理作用,阐明了引起突变HNF1B的肾脏疾病的发育起源。