scholarly journals Molecular determinants of WNT9b responsiveness in nephron progenitor cells

2018 ◽  
Author(s):  
Kyle K. Dickinson ◽  
Leah C. Hammond ◽  
Courtney M. Karner ◽  
Nicholas D. Hastie ◽  
Thomas J. Carroll ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Wnt Signaling Pathway ◽  
Mouse Kidney ◽  
Luciferase Reporter ◽  
Metanephric Mesenchyme ◽  
Ureteric Bud ◽  
Embryonic Mouse ◽  
Luciferase Reporter Plasmid ◽  
Sirna Knockdown ◽  
Nephron Progenitor

AbstractPrimed nephron progenitor cells (NPCs) appear in metanephric mesenchyme by Ell.5 and differentiate in response to the inductive WNT9b signal from the ureteric bud. However, the NPC WNT-receptor complex is unknown. We obtained M15 cells from E10.5 mesonephric mesenchyme and systematically analyzed components required for canonical WNT9b-responsiveness. When M15 cells were transfected with a (β-catenin luciferase reporter plasmid, exposure to recombinant WNT9b resulted in minimal luciferase activity. We then analyzed mRNA-expression of WNT-pathway components and identified Fzdl-6 and Lrp6 transcripts but not RSPO1. When M15 cells were treated with recombinant RSPO1 the response to transfected WNT9b was augmented 4.8-fold. Co-transfection of M15 cells with Fzd5 (but no other Fzd family member) further increased the WNT9b signal to 16.8-fold and siRNA knockdown of Fzd5 reduced the signal by 52%. Knockdown of Lrp6 resulted in 60% WNT9b signal reduction. We confirmed Fzd5, Lrp6 and RSPO1 rrtRNA expression in CITED1(+) NPCs from E15.5 embryonic mouse kidney. Thus, while many WNT signaling-pathway components are present by E10.5, optimum responsiveness of Ell.5 cap mesenchyme requires that NPCs acquire RSPO1, FZD5 and LRP6.Summary StatementResponsiveness to the inductive WMT9b signal from ureteric bud is crucial for nephrogenesis. Here we analyze the molecules needed to prime nephron progenitor cells in embryonic mouse kidney.

Regulation of BMP7 expression during kidney development

Development ◽  
1998 ◽  
Vol 125 (17) ◽  
pp. 3473-3482 ◽  
Author(s):  
R.E. Godin ◽  
N.T. Takaesu ◽  
E.J. Robertson ◽  
A.T. Dudley
Keyword(s):  
Wnt Signaling ◽  
Kidney Development ◽  
Tooth Development ◽  
Expression Patterns ◽  
Wnt Signaling Pathway ◽  
Sodium Chlorate ◽  
Bmp Signaling ◽  
Proteoglycan Synthesis ◽  
Metanephric Mesenchyme ◽  
Ureteric Bud

Members of the Bone Morphogenetic Protein (BMP) family exhibit overlapping and dynamic expression patterns throughout embryogenesis. However, little is known about the upstream regulators of these important signaling molecules. There is some evidence that BMP signaling may be autoregulative as demonstrated for BMP4 during tooth development. Analysis of BMP7 expression during kidney development, in conjunction with studies analyzing the effect of recombinant BMP7 on isolated kidney mesenchyme, suggest that a similar mechanism may operate for BMP7. We have generated a beta-gal-expressing reporter allele at the BMP7 locus to closely monitor expression of BMP7 during embryonic kidney development. In contrast to other studies, our analysis of BMP7/lacZ homozygous mutant embryos, shows that BMP7 expression is not subject to autoregulation in any tissue. In addition, we have used this reporter allele to analyze the expression of BMP7 in response to several known survival factors (EGF, bFGF) and inducers of metanephric mesenchyme, including the ureteric bud, spinal cord and LiCl. These studies show that treatment of isolated mesenchyme with EGF or bFGF allows survival of the mesenchyme but neither factor is sufficient to maintain BMP7 expression in this population of cells. Rather, BMP7 expression in the mesenchyme is contingent on an inductive signal. Thus, the reporter allele provides a convenient marker for the induced mesenchyme. Interestingly LiCl has been shown to activate the Wnt signaling pathway, suggesting that BMP7 expression in the mesenchyme is regulated by a Wnt signal. Treatment of whole kidneys with sodium chlorate to disrupt proteoglycan synthesis results in the loss of BMP7 expression in the mesenchyme whereas expression in the epithelial components of the kidney are unaffected. Heterologous recombinations of ureteric bud with either limb or lung mesenchyme demonstrate that expression of BMP7 is maintained in this epithelial structure. Taken together, these data indicate that BMP7 expression in the epithelial components of the kidney is not dependent on cell-cell or cell-ECM interactions with the metanephric mesenchyme. By contrast, BMP7 expression in the metanephric mesenchyme is dependent on proteoglycans and possibly Wnt signaling.

scholarly journals Colocalization and Redistribution of Dishevelled and Actin during WNT-Induced Mesenchymal Morphogenesis

2000 ◽  
Vol 149 (7) ◽  
pp. 1433-1442 ◽  
Author(s):  
Monica A. Torres ◽  
W. James Nelson
Keyword(s):  
Gene Expression ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Wnt Signaling Pathway ◽  
Cell Spreading ◽  
Mesenchymal Cell ◽  
Mouse Kidney ◽  
Cell Morphogenesis ◽  
Embryonic Mouse ◽  
Stimulation Of

Activation of the Wnt signaling pathway is important for induction of gene expression and cell morphogenesis throughout embryonic development. We examined the subcellular localization of dishevelled, the immediate downstream component from the Wnt receptor, in the embryonic mouse kidney. Using immunofluorescence staining, confocal microscopy, and coimmunoprecipitation experiments, we show that dishevelled associates with actin fibers and focal adhesion plaques in metanephric mesenchymal cells. Stimulation of Wnt signaling leads to profound changes in metanephric mesenchymal cell morphology, including disruption of the actin cytoskeleton, increased cell spreading, and increased karyokinesis. Upon activation of Wnt signaling, dishevelled also accumulates in and around the nucleus. Casein kinase Iε colocalizes with dishevelled along actin fibers and in the perinuclear region, whereas axin and GSK-3 are only present around the nucleus. These data indicate a branched Wnt signaling pathway comprising a canonical signal that targets the nucleus and gene expression, and another signal that targets the cytoskeleton and regulates cell morphogenesis.

scholarly journals Three Optimized Methods for In Situ Quantification of Progenitor Cell Proliferation in Embryonic Kidneys Using BrdU, EdU, and PCNA

2019 ◽  
Vol 6 ◽  
pp. 205435811987193
Author(s):  
Rosalie E. O’Hara ◽  
Michel G. Arsenault ◽  
Blanca P. Esparza Gonzalez ◽  
Ashley Patriquen ◽  
Sunny Hartwig
Keyword(s):  
Cell Proliferation ◽  
Progenitor Cells ◽  
Kidney Development ◽  
Fluorescence Labeling ◽  
Nuclear Antigen ◽  
Ureteric Bud ◽  
Proliferating Cells ◽  
Advantages And Disadvantages ◽  
Nephron Progenitor

Background: Nephron progenitor cells derived from the metanephric mesenchyme undergo a complex balance of self-renewal and differentiation throughout kidney development to give rise to the mature nephron. Cell proliferation is an important index of progenitor population dynamics. However, accurate and reproducible in situ quantification of cell proliferation within progenitor populations can be technically difficult to achieve due to the complexity and harsh tissue treatment required of certain protocols. Objective: To optimize and compare the performance of the 3 most accurate S phase–specific labeling methods used for in situ detection and quantification of nephron progenitor and ureteric bud cell proliferation in the developing kidney, namely, 5-bromo-2’-deoxyuridine (BrdU), 5-ethynyl-2’-deoxyuridine (EdU), and proliferating cell nuclear antigen (PCNA). Methods: Protocols for BrdU, EdU, and PCNA were optimized for fluorescence labeling on paraformaldehyde-fixed, paraffin-embedded mouse kidney tissue sections, with co-labeling of nephron progenitor cells and ureteric bud with Six2 and E-cadherin antibodies, respectively. Image processing and analysis, including quantification of proliferating cells, were carried out using free ImageJ software. Results: All 3 methods detect similar ratios of nephron progenitor and ureteric bud proliferating cells. The BrdU staining protocol is the lengthiest and most complex protocol to perform, requires tissue denaturation, and is most subject to interexperimental signal variability. In contrast, bound PCNA and EdU protocols are relatively more straightforward, consistently yield clear results, and far more easily lend themselves to co-staining; however, the bound PCNA protocol requires substantive additional postexperimental analysis to distinguish the punctate nuclear PCNA staining pattern characteristic of proliferating cells. Conclusions: All 3 markers exhibit distinct advantages and disadvantages in quantifying cell proliferation in kidney progenitor populations, with EdU and PCNA protocols being favored due to greater technical ease and reproducibility of results associated with these methods.

scholarly journals Progenitor translatome changes coordinated by Tsc1 increase perception of Wnt signals to end nephrogenesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alison E. Jarmas ◽  
Eric W. Brunskill ◽  
Praneet Chaturvedi ◽  
Nathan Salomonis ◽  
Raphael Kopan
Keyword(s):  
Progenitor Cells ◽  
Gradual Increase ◽  
Tipping Point ◽  
Ureteric Bud ◽  
Self Renewal ◽  
Nephron Endowment ◽  
Nephron Progenitors ◽  
Nephron Progenitor

AbstractMammalian nephron endowment is determined by the coordinated cessation of nephrogenesis in independent niches. Here we report that translatome analysis in Tsc1+/− nephron progenitor cells from mice with elevated nephron numbers reveals how differential translation of Wnt antagonists over agonists tips the balance between self-renewal and differentiation. Wnt agonists are poorly translated in young niches, resulting in an environment with low R-spondin and high Fgf20 promoting self-renewal. In older niches we find increased translation of Wnt agonists, including R-spondin and the signalosome-promoting Tmem59, and low Fgf20, promoting differentiation. This suggests that the tipping point for nephron progenitor exit from the niche is controlled by the gradual increase in stability and possibly clustering of Wnt/Fzd complexes in individual cells, enhancing the response to ureteric bud-derived Wnt9b inputs and driving synchronized differentiation. As predicted by these findings, removing one Rspo3 allele in nephron progenitors delays cessation and increases nephron numbers in vivo.

scholarly journals Ureteric Bud Cells Programmed from Embryonic Stem Cells Obtain Competence for Secondary Induction in the Kidney

2019 ◽  
Author(s):  
Zenglai Tan ◽  
Aleksandra Rak-Raszewska ◽  
Ilya Skovorodkin ◽  
Seppo J. Vainio
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Progenitor Cells ◽  
Drug Testing ◽  
Kidney Development ◽  
Embryonic Stem ◽  
Metanephric Mesenchyme ◽  
Ureteric Bud ◽  
Direct Differentiation ◽  
Kidney Organoids

SUMMARYGeneration of kidney organoids from pluripotent stem cells (PSCs) is regarded as a potentially powerful way to study kidney development, disease, and regeneration. Direct differentiation of PSCs towards renal lineages is well studied, however, most of the studies relates to generation of nephron progenitor population from PSCs. Until now, differentiation of PSCs into ureteric bud (UB) progenitor cells demonstrates limited success. Here, we describe a simple, efficient and reproductive protocol to direct differentiation of mouse embryonic stem cells (mESCs) into UB progenitor cells. The mESC–derived UB cells were able to induce nephrogenesis when placed in the interaction with the primary metanephric mesenchyme (pMM). In generated kidney organoids, the embryonic pMM developed nephron structures and the mESC-derived UB cells formed network of collecting ducts, connected with the nephron tubules. Altogether, our studies established an uncomplicated and reproducible platform for kidney disease modelling, drug testing and regenerative medicine applications.

LIF, the ES-cell inhibition factor, reversibly blocks nephrogenesis in cultured mouse kidney rudiments

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 193-198 ◽  
Author(s):  
J.B. Bard ◽  
A.S. Ross
Keyword(s):  
Embryonic Stem ◽  
Mouse Kidney ◽  
Leukaemia Inhibitory Factor ◽  
Es Cell ◽  
Metanephric Mesenchyme ◽  
Ureteric Bud ◽  
Cell Inhibition ◽  
Striking Effect

Mouse kidney induction proceeds in vitro much as it does in vivo: the ureteric bud bifurcates to give collecting ducts while the mesenchyme condenses into aggregates which epithelialise and then elongate into tubules with glomerular and other nephron structures. We report here that the factor known as LIF (leukaemia inhibitory factor), which regulates the differentiation and growth of embryonic-stem (ES) and other cells in culture, has little effect in vitro on growth or on ureteric-bud morphogenesis other than to stimulate the bifurcation process. It does however exert a striking effect on the mesenchyme. At about four times the concentration required to inhibit ES-cell differentiation, LIF strongly but reversibly blocks the effects of metanephric mesenchyme induction: although mesenchyme condenses around growing duct tips, the number of mature nephrons that form over 6 days is reduced by 75% or more. The few nephrons that do develop in the presence of LIF probably come from mesenchyme already induced at the time of culture and are indistinguishable from those that form in controls as assayed by morphology, by X-gal staining of endogenous galactosidase and by antibodies to brush-border and CD15 antigens. There is a further unexpected feature of rudiments cultured in LIF which is absent in controls: they contain an unexpectedly high number of stable epithelialised aggregates that express laminin around their periphery and which do not develop further. These results argue that the process of nephrogenesis involves at least two distinct stages which can be blocked by LIF: the effect of the initial induction and the future development of epithelialised aggregates.(ABSTRACT TRUNCATED AT 250 WORDS)

Canonical WNT signaling during kidney development

2007 ◽  
Vol 293 (2) ◽  
pp. F494-F500 ◽  
Author(s):  
Diana M. Iglesias ◽  
Pierre-Alain Hueber ◽  
LeeLee Chu ◽  
Robert Campbell ◽  
Anne-Marie Patenaude ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Kidney Development ◽  
Wnt Signaling Pathway ◽  
Renal Tubules ◽  
Metanephric Mesenchyme ◽  
Ureteric Bud ◽  
Fetal Kidney ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

The canonical WNT signaling pathway plays a crucial role in patterning of the embryo during development, but little is known about the specific developmental events which are under WNT control. To understand more about how the WNT pathway orchestrates mammalian organogenesis, we studied the canonical β-catenin-mediated WNT signaling pathway in kidneys of mice bearing a β-catenin-responsive TCF/βGal reporter transgene. In metanephric kidney, intense canonical WNT signaling was evident in epithelia of the branching ureteric bud and in nephrogenic mesenchyme during its transition into renal tubules. WNT signaling activity is rapidly downregulated in maturing nephrons and becomes undetectable in postnatal kidney. Sites of TCF/βGal activity are in proximity to the known sites of renal WNT2b and WNT4 expression, and these WNTs stimulate TCF reporter activity in kidney cell lines derived from ureteric bud and metanephric mesenchyme lineages. When fetal kidney explants from HoxB7/GFP mice were exposed to the canonical WNT signaling pathway inhibitor, Dickkopf-1, arborization of the ureteric bud was significantly reduced. We conclude that restricted zones of intense canonical WNT signaling drive branching nephrogenesis in fetal kidney.

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

2014 ◽  
Vol 306 (7) ◽  
pp. F764-F772 ◽  
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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