Thakkar Kairavee, Yarlagadda Sunitha, Alkhudairy Lyan, Potter Andrew, Thorner Konrad, Chaturvedi Praneet, McCracken Kyle W, Salomonis Nathan, Kopan Raphael, Schuh Meredith P
Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
Department of Pharmacology and Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
bioRxiv. 2025 Aug 22:2025.08.18.670897. doi: 10.1101/2025.08.18.670897.
Prematurity is associated with low nephron endowment and an increased risk of chronic kidney disease. Human nephrogenesis is complete at 34-36 weeks gestation, with 60% of nephrons forming during the third trimester through lateral branch nephrogenesis (LBN). We hypothesized that a differentiated but dividing population of nephron progenitor cells (NPCs) would contribute to the amplification of nephrons in late gestation. Methods: Single-cell RNA-sequencing (scRNA-Seq) was performed on cortically-enriched fetal rhesus kidneys (n=9) from late second trimester and third trimester during LBN. This data was integrated with publicly available human scRNA-seq datasets from 8-18 weeks gestation kidneys (n=8) using state-of-the-art bioinformatics pipelines. Differentially expressed genes and ligand-receptor interactions were assessed and validated using RNAScope on human and rhesus archival tissue.
scRNA-Seq of 64,782 rhesus cells revealed 37 transcriptionally distinct cell populations, including 7,879 rhesus NPCs. Pseudotime analyses identified a late gestation-specific lineage branch of differentiated NPC in rhesus that was not observed in mid-gestation humans. Differential expression analyses identified increased , and and decreased , , , and within the late-gestation rhesus NPC compared to mid-gestation human NPC and increased SEMA3D within the rhesus UB tip, suggesting a compositional shift in WNT and SEMA signaling components within the naive NPC population during LBN.
The rhesus macaque uniquely enables molecular studies of late-gestation primate nephrogenesis. Our study suggests the hypothesis that a transitional state of self-renewing NPC supported by compositional shifts in key pathways may underlie the switch from branching phase nephrogenesis to lateral branch nephrogenesis and support ongoing nephron formation in late gestation.
早产与肾单位数量减少及慢性肾脏病风险增加有关。人类肾发生在妊娠34 - 36周时完成，60%的肾单位在妊娠晚期通过侧支肾发生（LBN）形成。我们推测，已分化但仍在分裂的肾单位祖细胞（NPC）群体有助于妊娠晚期肾单位的扩增。方法：对妊娠中期晚期和妊娠晚期富含皮质的恒河猴胎儿肾脏（n = 9）进行单细胞RNA测序（scRNA-Seq）。使用最先进的生物信息学管道，将该数据与来自妊娠8 - 18周肾脏（n = 8）的公开可用人类scRNA-seq数据集进行整合。使用RNAscope对人类和恒河猴存档组织评估并验证差异表达基因和配体-受体相互作用。
对64,782个恒河猴细胞进行scRNA-Seq分析，揭示了37个转录上不同的细胞群体，包括7,879个恒河猴NPC。伪时间分析确定了恒河猴中妊娠晚期特有的已分化NPC谱系分支，而在妊娠中期人类中未观察到。差异表达分析表明，与妊娠中期人类NPC相比，妊娠晚期恒河猴NPC中的 、 和 增加， 、 、 和 减少，并且恒河猴输尿管芽尖端的SEMA3D增加，这表明在LBN期间幼稚NPC群体中WNT和SEMA信号成分发生了组成变化。
恒河猴独特地能够对妊娠晚期灵长类动物肾发生进行分子研究。我们的研究提出了一个假设，即关键途径组成变化支持的自我更新NPC的过渡状态可能是从分支阶段肾发生向侧支肾发生转变的基础，并支持妊娠晚期持续的肾单位形成。
