Changes in gene expression patterns in the ureteric bud and metanephric mesenchyme in models of kidney development

Branching morphogenesis of the ureteric bud in response to unknown signals from the metanephric mesenchyme gives rise to the urinary collecting system and, via inductive signals from the ureteric bud, to recruitment of nephrons from undifferentiated mesenchyme. An established cell culture model for this process employs cells of ureteric bud origin (UB) cultured in extracellular matrix and stimulated with conditioned media (BSN-CM) from a metanephric mesenchymal cell line (H. Sakurai, E. J. Barros, T. Tsukamoto, J. Barasch, and S. K. Nigam. Proc. Natl. Acad. Sci. USA 94: 6279–6284, 1997.). In the presence of BSN-CM, the UB cells form branching tubular structures reminiscent of the branching ureteric bud. The pattern of gene regulation in this model of branching morphogenesis of the kidney collecting system was investigated using high-density cDNA arrays. Software and analytical methods were developed for the quantification and clustering of genes. With the use of a computational method termed “vector analysis,” genes were clustered according to the direction and magnitude of differential expression in n-dimensional log-space. Changes in gene expression in response to the BSN-CM consisted primarily of differential expression of transcription factors with previously described roles in morphogenesis, downregulation of pro-apoptotic genes accompanied by upregulation of anti-apoptotic genes, and upregulation of a small group of secreted products including growth factors, cytokines, and extracellular proteinases. Changes in expression are discussed in the context of a general model for epithelial branching morphogenesis. In addition, the cDNA arrays were used to survey expression of epithelial markers and secreted factors in UB and BSN cells, confirming the largely epithelial character of the former and largely mesenchymal character of the later. Specific morphologies (cellular processes, branching multicellular cords, etc.) were shown to correlate with the expression of different, but overlapping, genomic subsets, suggesting differences in morphogenetic mechanisms at these various steps in the evolution of branching tubules.

Download Full-text

Regulation of BMP7 expression during kidney development

Development ◽

10.1242/dev.125.17.3473 ◽

1998 ◽

Vol 125 (17) ◽

pp. 3473-3482 ◽

Cited By ~ 8

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.

Download Full-text

Zinc Finger Protein Sall2 Is Not Essential for Embryonic and Kidney Development

Molecular and Cellular Biology ◽

10.1128/mcb.23.1.62-69.2003 ◽

2003 ◽

Vol 23 (1) ◽

pp. 62-69 ◽

Cited By ~ 25

Author(s):

Akira Sato ◽

Yuko Matsumoto ◽

Urara Koide ◽

Yuki Kataoka ◽

Nobuaki Yoshida ◽

...

Keyword(s):

Gene Expression ◽

Kidney Development ◽

Zinc Finger Protein ◽

Expression Patterns ◽

Perinatal Period ◽

Gene Expression Patterns ◽

Homeotic Gene ◽

Finger Protein ◽

Family Gene ◽

Deficient Mice

ABSTRACT SALL/Sall is a mammalian homolog of the Drosophila region-specific homeotic gene spalt (sal), and heterozygous mutations in SALL1 in humans lead to Townes-Brocks syndrome. We earlier reported that mice deficient in Sall1 die in the perinatal period and that kidney agenesis or severe dysgenesis are present. We have now generated mice lacking Sall2, another Sall family gene. Although Sall2 is expressed mostly in an overlapping fashion versus that of Sall1, Sall2-deficient mice show no apparent abnormal phenotypes. Morphology and gene expression patterns of the mutant kidney were not affected. Mice lacking both Sall1 and Sall2 show kidney phenotypes comparable to those of Sall1 knockout, thereby demonstrating the dispensable roles of Sall2 in embryonic and kidney development.

Download Full-text

Hoxa11andHoxd11regulate branching morphogenesis of the ureteric bud in the developing kidney

Development ◽

10.1242/dev.128.11.2153 ◽

2001 ◽

Vol 128 (11) ◽

pp. 2153-2161 ◽

Cited By ~ 3

Author(s):

Larry T. Patterson ◽

Martina Pembaur ◽

S. Steven Potter

Keyword(s):

Gene Expression ◽

Kidney Development ◽

Growth Failure ◽

Immunohistochemical Analysis ◽

Branching Morphogenesis ◽

Metanephric Mesenchyme ◽

Ureteric Bud ◽

Metanephric Kidney ◽

Normal Gene ◽

Ureteric Buds

Hoxa11 and Hoxd11 are functionally redundant during kidney development. Mice with homozygous null mutation of either gene have normal kidneys, but double mutants have rudimentary, or in extreme cases, absent kidneys. We have examined the mechanism for renal growth failure in this mouse model and find defects in ureteric bud branching morphogenesis. The ureteric buds are either unbranched or have an atypical pattern characterized by lack of terminal branches in the midventral renal cortex. The mutant embryos show that Hoxa11 and Hoxd11 control development of a dorsoventral renal axis. By immunohistochemical analysis, Hoxa11 expression is restricted to the early metanephric mesenchyme, which induces ureteric bud formation and branching. It is not found in the ureteric bud. This suggests that the branching defect had been caused by failure of mesenchyme to epithelium signaling. In situ hybridizations with Wnt7b, a marker of the metanephric kidney, show that the branching defect was not simply the result of homeotic transformation of metanephros to mesonephros. Absent Bf2 and Gdnf expression in the midventral mesenchyme, findings that could by themselves account for branching defects, shows that Hoxa11 and Hoxd11 are necessary for normal gene expression in the ventral mesenchyme. Attenuation of normal gene expression along with the absence of a detectable proliferative or apoptotic change in the mutants show that one function of Hoxa11 and Hoxd11 in the developing renal mesenchyme is to regulate differentiation necessary for mesenchymal-epithelial reciprocal inductive interactions.

Download Full-text

Single-cell analysis of progenitor cell dynamics and lineage specification of the human fetal kidney

10.1101/258798 ◽

2018 ◽

Cited By ~ 1

Author(s):

Rajasree Menon ◽

Edgar A. Otto ◽

Austin Kokoruda ◽

Jian Zhou ◽

Zidong Zhang ◽

...

Keyword(s):

Gene Expression ◽

Animal Models ◽

Single Cell ◽

Kidney Development ◽

Cell Types ◽

Specific Cell ◽

Metanephric Mesenchyme ◽

Ureteric Bud ◽

Expression Array ◽

Cell Dynamics

ABSTRACTThe mammalian kidney develops through repetitive and reciprocal interactions between the ureteric bud and the metanephric mesenchyme to give rise to the entire collecting system and the nephrons, respectively. Most of our knowledge of the developmental regulators driving this process has been gained from the study of gene expression and functional genetics in mice and other animal models. In order to shed light on human kidney development, we have used singlecell transcriptomics to characterize gene expression in different cell population, and to study individual cell dynamics and lineage trajectories during development. Single cell transcriptome analyses of 3,865 cells identified 17 clusters of specific cell types as defined by their gene expression profile, including markers of ureteric bud tip- and metanephric mesenchyme-specific progenitors, as well as their intermediate and differentiated lineages including the mature collecting ducts, the renal vesicle and comma- and s-shaped bodies, immature and mature podocytes, proximal tubules, loops of Henle and distal tubules. Other lineages identified include mesangium and cortical and medullary interstitium, endothelial and immune cells as well as hematopoietic cells. Novel markers for these cell types were revealed in the analysis as well as components of key signaling pathways driving renal development in animal models. Altogether, we provide a comprehensive and dynamic gene expression array of the human developing kidney at the single-cell level.

Download Full-text