Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio.
Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
J Am Soc Nephrol. 2021 May 3;32(5):1097-1112. doi: 10.1681/ASN.2020101459. Epub 2021 Mar 31.
Most nephrons are added in late gestation. Truncated extrauterine nephrogenesis in premature infants results in fewer nephrons and significantly increased risk for CKD in adulthood. To overcome the ethical and technical difficulties associated with studies of late-gestation human fetal kidney development, third-trimester rhesus macaques served as a model to understand lateral branch nephrogenesis (LBN) at the molecular level.
Immunostaining and 3D rendering assessed morphology. Single-cell (sc) and single-nucleus (sn) RNA-Seq were performed on four cortically enriched fetal rhesus kidneys of 129-131 days gestational age (GA). An integrative bioinformatics strategy was applied across single-cell modalities, species, and time. RNAScope validation studies were performed on human archival tissue.
Third-trimester rhesus kidney undergoes human-like LBN. scRNA-Seq of 23,608 cells revealed 37 transcriptionally distinct cell populations, including naïve nephron progenitor cells (NPCs), with the prior noted marker genes , , and (c25). These same populations and markers were reflected in snRNA-Seq of 5972 nuclei. Late-gestation rhesus NPC markers resembled late-gestation murine NPC, whereas early second-trimester human NPC markers aligned to midgestation murine NPCs. New, age-specific rhesus NPCs () and ureteric buds ( and TWIST) predicted markers were verified in late-gestation human archival samples.
Rhesus macaque is the first model of LBN, enabling molecular studies of late gestation, human-like nephrogenesis. These molecular findings support the hypothesis that aging nephron progenitors have a distinct molecular signature and align to their earlier human counterparts, with unique markers highlighting LBN-specific progenitor maturation.
大多数肾单位在妊娠晚期形成。早产儿的子宫外肾单位发育不全导致肾单位减少，成年后患 CKD 的风险显著增加。为了克服研究晚期人类胎儿肾脏发育相关的伦理和技术困难，第三个三月龄恒河猴被用作模型，以在分子水平上理解侧支肾发生（LBN）。
免疫染色和 3D 渲染评估形态。对四个皮质丰富的 129-131 天妊娠龄（GA）恒河猴胎儿肾脏进行单细胞（sc）和单核（sn）RNA-Seq。应用整合的生物信息学策略对单细胞模式、物种和时间进行分析。对人类存档组织进行 RNAScope 验证研究。
第三个三月龄恒河猴肾脏经历了类似人类的 LBN。对 23608 个细胞进行 scRNA-Seq 显示了 37 个转录上不同的细胞群体，包括幼稚肾祖细胞（NPCs），具有先前提到的标记基因 、 和 （c25）。这些相同的群体和标记也反映在 5972 个核的 snRNA-Seq 中。晚期恒河猴 NPC 标记类似于晚期鼠 NPC，而早期第二个三月龄人类 NPC 标记与中期鼠 NPC 一致。新的、年龄特异性的恒河猴 NPC （）和输尿管芽（和 TWIST）预测标记在晚期人类存档样本中得到了验证。
恒河猴是第一个 LBN 模型，使晚期妊娠、类似人类的肾发生的分子研究成为可能。这些分子发现支持这样的假设，即老化的肾祖细胞具有独特的分子特征，并与它们早期的人类对应物相一致，具有独特的标记突出了 LBN 特异性祖细胞的成熟。
