Macrophages restrict the nephrogenic field and promote endothelial connections during kidney development

The origins and functions of kidney macrophages in the adult have been explored, but their roles during development remain largely unknown. Here we characterise macrophage arrival, localisation, heterogeneity, and functions during kidney organogenesis. Using genetic approaches to ablate macrophages, we identify a role for macrophages in nephron progenitor cell clearance as mouse kidney development begins. Throughout renal organogenesis, most kidney macrophages are perivascular and express F4/80 and CD206. These macrophages are enriched for mRNAs linked to developmental processes, such as blood vessel morphogenesis. Using antibody-mediated macrophage-depletion, we show macrophages support vascular anastomoses in cultured kidney explants. We also characterise a subpopulation of galectin-3+ (Gal3+) myeloid cells within the developing kidney. Our findings may stimulate research into macrophage-based therapies for renal developmental abnormalities and have implications for the generation of bioengineered kidney tissues.

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Branching morphogenesis in the developing kidney is not impacted by nephron formation or integration

eLife ◽

10.7554/elife.38992 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 7

Author(s):

Kieran M Short ◽

Alexander N Combes ◽

Valerie Lisnyak ◽

James G Lefevre ◽

Lynelle K Jones ◽

...

Keyword(s):

Progenitor Cell ◽

Kidney Development ◽

Developmental Process ◽

Branching Morphogenesis ◽

Ureteric Bud ◽

Collecting Ducts ◽

Developing Kidney ◽

Developmental Feature ◽

Nephron Progenitor ◽

The Impact

Branching morphogenesis of the ureteric bud is integral to kidney development; establishing the collecting ducts of the adult organ and driving organ expansion via peripheral interactions with nephron progenitor cells. A recent study suggested that termination of tip branching within the developing kidney involved stochastic exhaustion in response to nephron formation, with such a termination event representing a unifying developmental process evident in many organs. To examine this possibility, we have profiled the impact of nephron formation and maturation on elaboration of the ureteric bud during mouse kidney development. We find a distinct absence of random branch termination events within the kidney or evidence that nephrogenesis impacts the branching program or cell proliferation in either tip or progenitor cell niches. Instead, organogenesis proceeds in a manner indifferent to the development of these structures. Hence, stochastic cessation of branching is not a unifying developmental feature in all branching organs.

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Troy/TNFRSF19 marks epithelial progenitor cells during mouse kidney development that continue to contribute to turnover in adult kidney

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1714145115 ◽

2017 ◽

Vol 114 (52) ◽

pp. E11190-E11198 ◽

Cited By ~ 6

Author(s):

Frans Schutgens ◽

Maarten B. Rookmaaker ◽

Francis Blokzijl ◽

Ruben van Boxtel ◽

Robert Vries ◽

...

Keyword(s):

Progenitor Cells ◽

Progenitor Cell ◽

Kidney Development ◽

Collecting Duct ◽

Adult Kidney ◽

Cell Property ◽

Developing Kidney ◽

Nephron Progenitor ◽

Epithelial Progenitor Cells

During kidney development, progressively committed progenitor cells give rise to the distinct segments of the nephron, the functional unit of the kidney. Similar segment-committed progenitor cells are thought to be involved in the homeostasis of adult kidney. However, markers for most segment-committed progenitor cells remain to be identified. Here, we evaluate Troy/TNFRSF19 as a segment-committed nephron progenitor cell marker. Troy is expressed in the ureteric bud during embryonic development. During postnatal nephrogenesis, Troy+ cells are present in the cortex and papilla and display an immature tubular phenotype. Tracing of Troy+ cells during nephrogenesis demonstrates that Troy+ cells clonally give rise to tubular structures that persist for up to 2 y after induction. Troy+ cells have a 40-fold higher capacity than Troy− cells to form organoids, which is considered a stem cell property in vitro. In the adult kidney, Troy+ cells are present in the papilla and these cells continue to contribute to collecting duct formation during homeostasis. The number of Troy-derived cells increases after folic acid-induced injury. Our data show that Troy marks a renal stem/progenitor cell population in the developing kidney that in adult kidney contributes to homeostasis, predominantly of the collecting duct, and regeneration.

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BET Proteins Regulate Expression of Osr1 in Early Kidney Development

Biomedicines ◽

10.3390/biomedicines9121878 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1878

Author(s):

Janina Schreiber ◽

Nastassia Liaukouskaya ◽

Lars Fuhrmann ◽

Alexander-Thomas Hauser ◽

Manfred Jung ◽

...

Keyword(s):

Gene Expression ◽

Progenitor Cell ◽

Kidney Development ◽

Gene Activation ◽

Renal Development ◽

Prenatal Programming ◽

Bet Inhibitor ◽

Bet Inhibitors ◽

Nephron Progenitor

In utero renal development is subject to maternal metabolic and environmental influences affecting long-term renal function and the risk of developing chronic kidney failure and cardiovascular disease. Epigenetic processes have been implicated in the orchestration of renal development and prenatal programming of nephron number. However, the role of many epigenetic modifiers for kidney development is still unclear. Bromodomain and extra-terminal domain (BET) proteins act as histone acetylation reader molecules and promote gene transcription. BET family members Brd2, Brd3 and Brd4 are expressed in the nephrogenic zone during kidney development. Here, the effect of the BET inhibitor JQ1 on renal development is evaluated. Inhibition of BET proteins via JQ1 leads to reduced growth of metanephric kidney cultures, loss of the nephron progenitor cell population, and premature and disturbed nephron differentiation. Gene expression of key nephron progenitor transcription factor Osr1 is downregulated after 24 h BET inhibition, while Lhx1 and Pax8 expression is increased. Mining of BRD4 ChIP-seq and gene expression data identify Osr1 as a key factor regulated by BRD4-controlled gene activation. Inhibition of BRD4 by BET inhibitor JQ1 leads to downregulation of Osr1, thereby causing a disturbance in the balance of nephron progenitor cell self-renewal and premature differentiation of the nephron, which ultimately leads to kidney hypoplasia and disturbed nephron development. This raises questions about the potential teratogenic effects of BET inhibitors for embryonic development. In summary, our work highlights the role of BET proteins for prenatal programming of nephrogenesis and identifies Osr1 as a potential target of BET proteins.

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Chromatin Remodelers Interact with Eya1 and Six2 to Target Enhancers to Control Nephron Progenitor Cell Maintenance

Journal of the American Society of Nephrology ◽

10.1681/asn.2021040525 ◽

2021 ◽

Vol 32 (11) ◽

pp. 2815-2833

Author(s):

Jun Li ◽

Jinshu Xu ◽

Huihui Jiang ◽

Ting Zhang ◽

Aarthi Ramakrishnan ◽

...

Keyword(s):

Progenitor Cell ◽

Kidney Development ◽

Regulatory Elements ◽

Proximal Promoter ◽

Specific Expression ◽

Self Renewal ◽

Content Type ◽

Nephron Progenitors ◽

Genome Wide ◽

Nephron Progenitor

BackgroundEya1 is a critical regulator of nephron progenitor cell specification and interacts with Six2 to promote NPC self-renewal. Haploinsufficiency of these genes causes kidney hypoplasia. However, how the Eya1-centered network operates remains unknown.MethodsWe engineered a 2×HA-3×Flag-Eya1 knock-in mouse line and performed coimmunoprecipitation with anti-HA or -Flag to precipitate the multitagged-Eya1 and its associated proteins. Loss-of-function, transcriptome profiling, and genome-wide binding analyses for Eya1's interacting chromatin-remodeling ATPase Brg1 were carried out. We assayed the activity of the cis-regulatory elements co-occupied by Brg1/Six2 in vivo.ResultsEya1 and Six2 interact with the Brg1-based SWI/SNF complex during kidney development. Knockout of Brg1 results in failure of metanephric mesenchyme formation and depletion of nephron progenitors, which has been linked to loss of Eya1 expression. Transcriptional profiling shows conspicuous downregulation of important regulators for nephrogenesis in Brg1-deficient cells, including Lin28, Pbx1, and Dchs1-Fat4 signaling, but upregulation of podocyte lineage, oncogenic, and cell death–inducing genes, many of which Brg1 targets. Genome-wide binding analysis identifies Brg1 occupancy to a distal enhancer of Eya1 that drives nephron progenitor–specific expression. We demonstrate that Brg1 enrichment to two distal intronic enhancers of Pbx1 and a proximal promoter region of Mycn requires Six2 activity and that these Brg1/Six2-bound enhancers govern nephron progenitor–specific expression in response to Six2 activity.ConclusionsOur results reveal an essential role for Brg1, its downstream pathways, and its interaction with Eya1-Six2 in mediating the fine balance among the self-renewal, differentiation, and survival of nephron progenitors.

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Computational Modelling of Nephron Progenitor Cell Movement and Aggregation during Kidney Organogenesis

10.1101/2020.01.14.905711 ◽

2020 ◽

Author(s):

Pauli Tikka ◽

Moritz Mercker ◽

Ilya Skovorodkin ◽

Ulla Saarela ◽

Seppo Vainio ◽

...

Keyword(s):

Cell Adhesion ◽

Potts Model ◽

Progenitor Cell ◽

Ex Vivo ◽

Cell Movement ◽

Ureteric Bud ◽

Cellular Potts Model ◽

Kidney Organogenesis ◽

Nephron Progenitor ◽

Cell Cell

AbstractDuring early kidney organogenesis, nephron progenitor (NP) cells move from the tip to the corner region of the ureteric bud (UB) branches in order to form the pretubular aggregate, the early structure giving rise to nephron formation. Chemotaxis and cell-cell adhesion differences are believed to drive cell patterning during this critical period of organogenesis, but the spatiotemporal organization of this process is incompletely understood.We applied a Cellular Potts model to explore to how these processes contribute to directed cell movement and aggregation. Model parameters were estimated based on fitting to experimental data obtained in ex vivo kidney explant and dissociation-reaggregation organoid culture studies.Our simulations indicated that optimal enrichment and aggregation of NP cells in the UB corner niche requires chemoattractant secretion from both the UB epithelial cells and the NP cells themselves, as well as differences in cell-cell adhesion energies. Furthermore, NP cells were observed, both experimentally and by modelling, to move at higher speed in the UB corner as compared to the tip region where they originated. The existence of different cell speed domains along the UB was confirmed using self-organizing map analysis.In summary, we demonstrated the suitability of a Cellular Potts Model approach to simulate cell movement and patterning during early nephrogenesis. Further refinement of the model should allow us to recapitulate the effects of developmental changes of cell phenotypes and molecular crosstalk during organ development.Author SummaryThe emergence of tissue patterns during vertebrate development is a major interest of both experimental research and biocomputational modelling. In this study, we established a Cellular Potts Model to explore cellular processes during early kidney development. The goal was to elucidate movements and aggregations of nephron progenitor cells. These precursor cells derive from mesenchymal cells around the ureteric buds and eventually form the epithelial structure of the nephron. Moreover, we wanted to explore computationally the mechanisms how these cells segregate from metanephric mesenchyme and move towards the location where the nephron will be formed. Utilizing the Compucell3D simulation software, we developed a model which assumes that nephron progenitor movement and aggregation is governed by only two mechanisms, i.e. cell-cell adhesion differences between cell types and nephron progenitor cell chemotaxis in response to chemoattractant secretion from two sources. These sources were either the epithelial cells of a static ureteric bud and/or the nephron progenitor cells themselves. The simulations indicated faster average cell speeds near the ureteric bud corner, the target region of cell movement and aggregation, and slower speeds near the place of origin, the tip of ureteric bud. The results were validated by comparison of the model predictions with experimental data from two ex vivo embryonic kidney models and a computational optimization protocol.

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Dicer function is required in the metanephric mesenchyme for early kidney development

AJP Renal Physiology ◽

10.1152/ajprenal.00426.2013 ◽

2014 ◽

Vol 306 (7) ◽

pp. F764-F772 ◽

Cited By ~ 25

Author(s):

Jessica Y. S. Chu ◽

Sunder Sims-Lucas ◽

Daniel S. Bushnell ◽

Andrew J. Bodnar ◽

Jordan A. Kreidberg ◽

...

Keyword(s):

Target Genes ◽

Kidney Development ◽

Metanephric Mesenchyme ◽

Ureteric Bud ◽

Rnase Iii ◽

Nephron Progenitors ◽

Proapoptotic Protein ◽

Kidney Organogenesis ◽

Regulatory Rnas ◽

Nephron Progenitor

MicroRNAs (miRNAs) are small, noncoding regulatory RNAs that act as posttranscriptional repressors by binding to the 3′-untranslated region (3′-UTR) of target genes. They require processing by Dicer, an RNase III enzyme, to become mature regulatory RNAs. Previous work from our laboratory revealed critical roles for miRNAs in nephron progenitors at midgestation (Ho J, Pandey P, Schatton T, Sims-Lucas S, Khalid M, Frank MH, Hartwig S, Kreidberg JA. J Am Soc Nephrol 22: 1053–1063, 2011). To interrogate roles for miRNAs in the early metanephric mesenchyme, which gives rise to nephron progenitors as well as the renal stroma during kidney development, we conditionally ablated Dicer function in this lineage. Despite normal ureteric bud outgrowth and condensation of the metanephric mesenchyme to form nephron progenitors, early loss of miRNAs in the metanephric mesenchyme resulted in severe renal dysgenesis. Nephron progenitors are initially correctly specified in the mutant kidneys, with normal expression of several transcription factors known to be critical in progenitors, including Six2, Pax2, Sall1, and Wt1. However, there is premature loss of the nephron progenitor marker Cited1, marked apoptosis, and increased expression of the proapoptotic protein Bim shortly after the initial inductive events in early kidney development. Subsequently, there is a failure in ureteric bud branching and nephron progenitor differentiation. Taken together, our data demonstrate a previously undetermined requirement for miRNAs during early kidney organogenesis and indicate a crucial role for miRNAs in regulating the survival of this lineage.

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The roles of histone deacetylases in kidney development and disease

Clinical and Experimental Nephrology ◽

10.1007/s10157-020-01995-5 ◽

2021 ◽

Author(s):

Hongbing Liu

Keyword(s):

Histone Deacetylases ◽

Molecular Mechanisms ◽

Kidney Development ◽

Kidney Diseases ◽

Critical Role ◽

Hdac Inhibitors ◽

Developing Kidney ◽

Nephron Progenitor ◽

Class I Hdacs ◽

Progression Of Renal Disease

AbstractHistone deacetylases (HDACs) are important epigenetic regulators that mediate deacetylation of both histone and non-histone proteins. HDACs, especially class I HDACs, are highly expressed in developing kidney and subject to developmental control. HDACs play an important role in kidney formation, especial nephron progenitor maintenance and differentiation. Several lines of evidence support the critical role of HDACs in the development and progression of various kidney diseases. HDAC inhibitors (HDACis) are very effective in the prevention and treatment of kidney diseases (including kidney cancer). A better understanting of the molecular mechanisms underlying the role(s) of HDACs in the pathogenesis and progression of renal disease are likely to be of great help in developing more effective and less toxic selective HDAC inhibitors and combinatorial therapeutics.

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