Meredith P Schuh1,2,3, Lyan Alkhudairy2, Andrew Potter3, S Steven Potter4,3, Kashish Chetal5, Kairavee Thakkar5,6, Nathan Salomonis1,5, Raphael Kopan1,3. 1. Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio meredith.schuh@cchmc.org nathan.salomonis@cchmc.org raphael.kopan@cchmc.org. 2. Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio. 3. Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio. 4. Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio. 5. Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio. 6. Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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 CITED1, MEOX1, and EYA1 (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 (SHISA8) and ureteric buds (POU3F4 and TWIST) predicted markers were verified in late-gestation human archival samples. CONCLUSIONS: Rhesus macaque is the first model of bona fide 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.
BACKGROUND: 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. METHODS: 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. RESULTS: 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 CITED1, MEOX1, and EYA1 (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 (SHISA8) and ureteric buds (POU3F4 and TWIST) predicted markers were verified in late-gestation human archival samples. CONCLUSIONS: Rhesus macaque is the first model of bona fide 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.
Authors: Sarah L White; Vlado Perkovic; Alan Cass; Choon Lan Chang; Neil R Poulter; Tim Spector; Leigh Haysom; Jonathan C Craig; Isa Al Salmi; Steven J Chadban; Rachel R Huxley Journal: Am J Kidney Dis Date: 2009-04-01 Impact factor: 8.860
Authors: Alexander C Zambon; Stan Gaj; Isaac Ho; Kristina Hanspers; Karen Vranizan; Chris T Evelo; Bruce R Conklin; Alexander R Pico; Nathan Salomonis Journal: Bioinformatics Date: 2012-06-27 Impact factor: 6.937