scholarly journals Nephron progenitor maintenance is controlled through FGFs and Sprouty1 Interaction

2020 ◽  
Author(s):  
Sung-Ho Huh ◽  
Ligyeom Ha ◽  
Hee-Seong Jang
Keyword(s):  
Cell Death ◽  
Tyrosine Kinases ◽  
Kidney Development ◽  
Renal Agenesis ◽  
Treatment Strategies ◽  
Loss Of Function ◽  
Nephron Progenitors ◽  
Novel Treatment Strategies ◽  
Nephron Progenitor ◽  
Progenitor Maintenance

AbstractThe nephron progenitor cells (NPCs) give rise to all segments of functional nephrons and are of great interest due to their potential as a source for novel treatment strategies for kidney disease. Fibroblast growth factor (FGF) signal plays pivotal roles in generating and maintaining NPCs during kidney development. However, molecule(s) regulating FGF signal during nephron development is not known. Sprouty (SPRY) is an antagonist of receptor tyrosine kinases. During kidney development, SPRY1 is expressed in the ureteric buds (UBs) and regulates UB branching by antagonizing Ret-GDNF signal. Here, we provide evidence that SPRY1 expressed in NPCs modulates activity of FGF signal in NPCs and regulates NPC stemness. Haploinsufficiency of Spry1 rescues bilateral renal agenesis and premature NPC differentiation caused by loss of Fgf9 and Fgf20. In addition, haploinsufficiency of Spry1 rescues NPC proliferation and cell death defects induced by loss of Fgf9 and Fgf20. In the absence of SPRY1, FGF9 and FGF20, another FGF ligand, FGF8 promotes nephrogenesis. Deleting both Fgf8 and Fgf20 results in kidney agenesis and defects in NPC proliferation and cell death. Rescue of loss of Fgf9 and Fgf20 induced renal agenesis by Spry1 haploinsufficiency was reversed when one copy of Fgf8 was deleted. These findings indicate the importance of the balance between positive and negative signal during NPC maintenance. Failure of the balance may underlie some human congenital kidney malformation.Significance StatementNephrons are functional units of kidney to filter blood to excrete wastes and regulate osmolarity and ion concentrations. Nephrons are derived from nephron progenitors. Nephron progenitors are depleted during kidney development which makes it unable to regenerate nephrons. Therefore, understanding signaling molecules regulating nephron progenitor generation and maintenance is of great interest for the future kidney regenerative medicine. Here, we show that Sprouty1 regulates nephron progenitor maintenance by inhibiting FGF signal. Deletion of Sprouty1 rescues renal agenesis and nephron progenitor depletion in the Fgf9/20 loss-of-function kidneys. Further decrease of FGF signal by deleting one copy of Fgf8 makes kidneys irresponsive to Sprouty1 resulting in failure of nephron progenitor maintenance. This study thus identifies the reciprocal function of FGF-Sprouty1 signal during nephron progenitor development.

scholarly journals Nephron Progenitor Maintenance Is Controlled through Fibroblast Growth Factors and Sprouty1 Interaction

2020 ◽  
Vol 31 (11) ◽  
pp. 2559-2572
Author(s):  
Sung-Ho Huh ◽  
Ligyeom Ha ◽  
Hee-Seong Jang
Keyword(s):  
Cell Death ◽  
Tyrosine Kinases ◽  
Kidney Development ◽  
Renal Agenesis ◽  
Treatment Strategies ◽  
Fibroblast Growth ◽  
Fgf Signaling ◽  
Nephron Development ◽  
Novel Treatment Strategies ◽  
Nephron Progenitor

BackgroundNephron progenitor cells (NPCs) give rise to all segments of functional nephrons and are of great interest due to their potential as a source for novel treatment strategies for kidney disease. Fibroblast growth factor (FGF) signaling plays pivotal roles in generating and maintaining NPCs during kidney development, but little is known about the molecule(s) regulating FGF signaling during nephron development. Sprouty 1 (SPRY1) is an antagonist of receptor tyrosine kinases. Although SPRY1 antagonizes Ret-GDNF signaling, which modulates renal branching, its role in NPCs is not known.MethodsSpry1, Fgf9, and Fgf20 compound mutant animals were used to evaluate kidney phenotypes in mice to understand whether SPRY1 modulates FGF signaling in NPCs and whether FGF8 functions with FGF9 and FGF20 in maintaining NPCs.ResultsLoss of one copy of Spry1 counters effects of the loss of Fgf9 and Fgf20, rescuing bilateral renal agenesis premature NPC differentiation, NPC proliferation, and cell death defects. In the absence of SPRY1, FGF9, and FGF20, another FGF ligand, FGF8, promotes nephrogenesis. Deleting both Fgf8 and Fgf20 results in kidney agenesis, defects in NPC proliferation, and cell death. Deleting one copy of Fgf8 reversed the effect of deleting one copy of Spry1, which rescued the renal agenesis due to loss of Fgf9 and Fgf20.ConclusionsSPRY1 expressed in NPCs modulates the activity of FGF signaling and regulates NPC stemness. These findings indicate the importance of the balance between positive and negative signals during NPC maintenance.

scholarly journals Wnt/β-catenin signaling is required for the development of multiple nephron segments

2018 ◽  
Author(s):  
Patrick Deacon ◽  
Charles W Concodora ◽  
Eunah Chung ◽  
Joo-Seop Park
Keyword(s):  
Kidney Development ◽  
Critical Role ◽  
Proximal Tubules ◽  
Loss Of Function ◽  
Constitutive Activation ◽  
Nephron Segments ◽  
Mesenchymal To Epithelial Transition ◽  
Nephron Progenitors ◽  
Distal Tubules ◽  
Nephron Progenitor

The nephron is composed of distinct segments that perform unique physiological functions to generate urine. Little is known about how multipotent nephron progenitor cells differentiate into different nephron segments. It is well known that Wnt/β-catenin signaling regulates the maintenance and commitment of mesenchymal nephron progenitors during kidney development. However, it is not fully understood how it regulates nephron patterning after nephron progenitors undergo mesenchymal-to-epithelial transition. To address this, we performed β-catenin loss-of-function and gain-of-function studies in epithelial nephron progenitors in the mouse kidney. Consistent with a previous report, the formation of the renal corpuscle was defective in the absence of β-catenin. Interestingly, we found that epithelial nephron progenitors lacking β-catenin were able to form presumptive proximal tubules but that they failed to further develop into differentiated proximal tubules, suggesting that Wnt/β-catenin signaling plays a critical role in proximal tubule development. We also found that epithelial nephron progenitors lacking β-catenin failed to form the distal tubules. Constitutive activation of Wnt/β-catenin signaling blocked the proper formation of all nephron segments, suggesting tight regulation of Wnt/β-catenin signaling during nephron patterning. This work shows that Wnt/β-catenin signaling regulates the patterning of multiple nephron segments along the proximo-distal axis of the mammalian nephron.

scholarly journals Von Hippel-Lindau Acts as a Metabolic Switch Controlling Nephron Progenitor Differentiation

2019 ◽  
Vol 30 (7) ◽  
pp. 1192-1205 ◽  
Author(s):  
Kasey Cargill ◽  
Shelby L. Hemker ◽  
Andrew Clugston ◽  
Anjana Murali ◽  
Elina Mukherjee ◽  
...  
Keyword(s):  
Mitochondrial Respiration ◽  
Metabolic Regulation ◽  
Kidney Development ◽  
Developmentally Delayed ◽  
Metabolic Switch ◽  
Von Hippel Lindau ◽  
Conditional Deletion ◽  
Nephron Progenitors ◽  
Ubiquitin Ligase Complex ◽  
Nephron Progenitor

BackgroundNephron progenitors, the cell population that give rise to the functional unit of the kidney, are metabolically active and self-renew under glycolytic conditions. A switch from glycolysis to mitochondrial respiration drives these cells toward differentiation, but the mechanisms that control this switch are poorly defined. Studies have demonstrated that kidney formation is highly dependent on oxygen concentration, which is largely regulated by von Hippel-Lindau (VHL; a protein component of a ubiquitin ligase complex) and hypoxia-inducible factors (a family of transcription factors activated by hypoxia).MethodsTo explore VHL as a regulator defining nephron progenitor self-renewal versus differentiation, we bred Six2-TGCtg mice with VHLlox/lox mice to generate mice with a conditional deletion of VHL from Six2+ nephron progenitors. We used histologic, immunofluorescence, RNA sequencing, and metabolic assays to characterize kidneys from these mice and controls during development and up to postnatal day 21.ResultsBy embryonic day 15.5, kidneys of nephron progenitor cell–specific VHL knockout mice begin to exhibit reduced maturation of nephron progenitors. Compared with controls, VHL knockout kidneys are smaller and developmentally delayed by postnatal day 1, and have about half the number of glomeruli at postnatal day 21. VHL knockout nephron progenitors also exhibit persistent Six2 and Wt1 expression, as well as decreased mitochondrial respiration and prolonged reliance on glycolysis.ConclusionsOur findings identify a novel role for VHL in mediating nephron progenitor differentiation through metabolic regulation, and suggest that VHL is required for normal kidney development.

scholarly journals β-catenin regulates the formation of multiple nephron segments in the mouse kidney

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Patrick Deacon ◽  
Charles W. Concodora ◽  
Eunah Chung ◽  
Joo-Seop Park
Keyword(s):  
Kidney Development ◽  
Critical Role ◽  
Mouse Kidney ◽  
Proximal Tubules ◽  
Stable Form ◽  
Loss Of Function ◽  
Nephron Segments ◽  
Mesenchymal To Epithelial Transition ◽  
Nephron Progenitors ◽  
Nephron Segmentation

Abstract The nephron is composed of distinct segments that perform unique physiological functions. Little is known about how multipotent nephron progenitor cells differentiate into different nephron segments. It is well known that β-catenin signaling regulates the maintenance and commitment of mesenchymal nephron progenitors during kidney development. However, it is not fully understood how it regulates nephron segmentation after nephron progenitors undergo mesenchymal-to-epithelial transition. To address this, we performed β-catenin loss-of-function and gain-of-function studies in epithelial nephron progenitors in the mouse kidney. Consistent with a previous report, the formation of the renal corpuscle was defective in the absence of β-catenin. Interestingly, we found that epithelial nephron progenitors lacking β-catenin were able to form presumptive proximal tubules but that they failed to further develop into differentiated proximal tubules, suggesting that β-catenin signaling plays a critical role in proximal tubule development. We also found that epithelial nephron progenitors lacking β-catenin failed to form the distal tubules. Expression of a stable form of β-catenin in epithelial nephron progenitors blocked the proper formation of all nephron segments, suggesting tight regulation of β-catenin signaling during nephron segmentation. This work shows that β-catenin regulates the formation of multiple nephron segments along the proximo-distal axis of the mammalian nephron.

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

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.

scholarly journals Postnatal prolongation of mammalian nephrogenesis by excess fetal GDNF

Development ◽  
2021 ◽  
Vol 148 (10) ◽  
Author(s):  
Hao Li ◽  
Kristen Kurtzeborn ◽  
Jussi Kupari ◽  
Yujuan Gui ◽  
Edward Siefker ◽  
...  
Keyword(s):  
Cardiovascular Health ◽  
Postnatal Period ◽  
Activity Level ◽  
Ureteric Bud ◽  
Negative Effects ◽  
Multi Stage ◽  
Nephron Progenitors ◽  
Mechanistic Analysis ◽  
Nephron Progenitor ◽  
Progenitor Maintenance

ABSTRACT Nephron endowment, defined during the fetal period, dictates renal and related cardiovascular health throughout life. We show here that, despite its negative effects on kidney growth, genetic increase of GDNF prolongs the nephrogenic program beyond its normal cessation. Multi-stage mechanistic analysis revealed that excess GDNF maintains nephron progenitors and nephrogenesis through increased expression of its secreted targets and augmented WNT signaling, leading to a two-part effect on nephron progenitor maintenance. Abnormally high GDNF in embryonic kidneys upregulates its known targets but also Wnt9b and Axin2, with concomitant deceleration of nephron progenitor proliferation. Decline of GDNF levels in postnatal kidneys normalizes the ureteric bud and creates a permissive environment for continuation of the nephrogenic program, as demonstrated by morphologically and molecularly normal postnatal nephron progenitor self-renewal and differentiation. These results establish that excess GDNF has a bi-phasic effect on nephron progenitors in mice, which can faithfully respond to GDNF dosage manipulation during the fetal and postnatal period. Our results suggest that sensing the signaling activity level is an important mechanism through which GDNF and other molecules contribute to nephron progenitor lifespan specification.

scholarly journals Premature differentiation of nephron progenitors and dysregulation of gene pathways critical to kidney development in a model of preterm birth

2021 ◽  
Author(s):  
Aleksandra Cwiek ◽  
Masako Suzuki ◽  
Kimberly deRonde ◽  
Mark Conaway ◽  
Kevin Bennett ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Progenitor Cells ◽  
Kidney Development ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Neonatal Morbidity ◽  
Expression Of Genes ◽  
Nephron Progenitors ◽  
Nephron Progenitor ◽  
Lower Expression

Abstract Preterm birth is a leading cause of neonatal morbidity. Survivors have a greater risk for kidney dysfunction and hypertension. Little is known about the molecular changes that occur in the kidney of individuals born preterm. Here, we demonstrate that mice delivered two days prior to full term gestation undergo premature cessation of nephrogenesis, resulting in a lower glomerular density. Kidneys from preterm and term groups exhibited differences in gene expression profiles at 20- and 27-days post-conception, including significant differences in expression of fat-soluble vitamin-related genes. Kidneys of the preterm mice exhibited decreased proportions of endothelial cells and a lower expression of genes promoting angiogenesis compared to the term group. Kidneys from the preterm mice also had altered nephron progenitor subpopulations, early Six2 depletion, and altered Jag1 expression in the nephrogenic zone, consistent with premature differentiation of nephron progenitor cells. In conclusion, preterm birth alone was sufficient to shorten the duration of nephrogenesis and cause premature differentiation of nephron progenitor cells. These candidate genes and pathways may provide targets to improve kidney health in preterm infants.

scholarly journals A Bi-allelic Frameshift Mutation in NPNT Causes Bilateral Renal Agenesis in Humans

2021 ◽  
pp. ASN.2020121762
Author(s):  
Lei Dai ◽  
Jingzhi Li ◽  
Liangqun Xie ◽  
Weinan Wang ◽  
Yang Lu ◽  
...  
Keyword(s):  
Mouse Model ◽  
Kidney Development ◽  
Renal Agenesis ◽  
Genetic Diagnosis ◽  
Homozygosity Mapping ◽  
Loss Of Function ◽  
Fetal Ultrasonography ◽  
Whole Exome ◽  
Recessive Form

Background: Bilateral renal agenesis (BRA) is a lethal congenital anomaly caused by the failure of normal development of both kidneys early in embryonic development. Oligohydramnios upon fetal ultrasonography reveals BRA. Although exact causes are not clear, BRA is associated with mutations in many renal development genes. However, molecular diagnostics cannot pick up many clinical cases. Nephronectin (NPNT) may be a candidate protein for widening diagnosis. It is essential in kidney development and knockout of Npnt in mice frequently leads to kidney agenesis or hypoplasia. Methods: A consanguineous Han family experienced three cases of induced abortion in the second trimester of pregnancy due to suspicion of BRA. Whole-exome sequencing-(WES)-:based homozygosity mapping detected underlying genetic factors, and a knock-in mouse model confirmed the renal agenesis phenotype. Results: WES and evaluation of homozygous regions in II-3 and II-4 revealed a pathological homozygous frameshift variant in NPNT (NM_001184690:exon8:c.777dup/p.Lys260*), which leads to a premature stop in the next codon. The truncated NPNT protein exhibited decreased expression, as confirmed in vivo by the overexpression of WT and mutated NPNT. A knock-in mouse model homozygous for the detected Npnt mutation replicated the BRA phenotype. Conclusions: A biallelic loss-of-function NPNT mutation causing an autosomal recessive form of BRA in humans was confirmed by the corresponding phenotype of knock-in mice. Our results identify a novel genetic cause of BRA, revealing a new target for genetic diagnosis, prenatal diagnosis, and preimplantation diagnosis for families with BRA.

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.

scholarly journals In utero exposure to maternal diabetes impairs nephron progenitor differentiation

2019 ◽  
Vol 317 (5) ◽  
pp. F1318-F1330 ◽  
Author(s):  
Débora M. Cerqueira ◽  
Shelby L. Hemker ◽  
Andrew J. Bodnar ◽  
Daniella M. Ortiz ◽  
Favour O. Oladipupo ◽  
...  
Keyword(s):  
Congenital Anomalies ◽  
Kidney Development ◽  
Maternal Diabetes ◽  
Childbearing Age ◽  
Sine Oculis ◽  
Nephron Progenitors ◽  
Binding Factor ◽  
Nephron Progenitor ◽  
Canonical Wnt ◽  
Akita Mice

The incidence of diabetes mellitus has significantly increased among women of childbearing age, and it has been shown that prenatal exposure to maternal diabetes increases the risk of associated congenital anomalies of the kidney. Congenital anomalies of the kidney are among the leading causes of chronic kidney disease in children. To better understand the effect of maternal diabetes on kidney development, we analyzed wild-type offspring (DM_Exp) of diabetic Ins2+/C96Y mice (Akita mice). DM_Exp mice at postnatal day 34 have a reduction of ~20% in the total nephron number compared with controls, using the gold standard physical dissector/fractionator method. At the molecular level, the expression of the nephron progenitor markers sine oculis homeobox homolog 2 and Cited1 was increased in DM_Exp kidneys at postnatal day 2. Conversely, the number of early developing nephrons was diminished in DM_Exp kidneys. This was associated with decreased expression of the intracellular domain of Notch1 and the canonical Wnt target lymphoid enhancer binding factor 1. Together, these data suggest that the diabetic intrauterine environment impairs the differentiation of nephron progenitors into nephrons, possibly by perturbing the Notch and Wnt/β-catenin signaling pathways.

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