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Actin depolymerizing factors cofilin1 and destrin are required for ureteric bud branching morphogenesis.

Kuure S, Cebrian C, Machingo Q, Lu BC, Chi X, Hyink D, D'Agati V, Gurniak C, Witke W, Costantini F - PLoS Genet. (2010)

Bottom Line: The actin depolymerizing factors (ADFs) play important roles in several cellular processes that require cytoskeletal rearrangements, such as cell migration, but little is known about the in vivo functions of ADFs in developmental events like branching morphogenesis.Lack of Cfl1 and Dstn in the UB causes accumulation of filamentous actin, disruption of normal epithelial organization, and defects in cell migration.The results indicate that ADF activity, provided by either cofilin1 or destrin, is essential in UB epithelial cells for normal growth and branching.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America.

ABSTRACT
The actin depolymerizing factors (ADFs) play important roles in several cellular processes that require cytoskeletal rearrangements, such as cell migration, but little is known about the in vivo functions of ADFs in developmental events like branching morphogenesis. While the molecular control of ureteric bud (UB) branching during kidney development has been extensively studied, the detailed cellular events underlying this process remain poorly understood. To gain insight into the role of actin cytoskeletal dynamics during renal branching morphogenesis, we studied the functional requirements for the closely related ADFs cofilin1 (Cfl1) and destrin (Dstn) during mouse development. Either deletion of Cfl1 in UB epithelium or an inactivating mutation in Dstn has no effect on renal morphogenesis, but simultaneous lack of both genes arrests branching morphogenesis at an early stage, revealing considerable functional overlap between cofilin1 and destrin. Lack of Cfl1 and Dstn in the UB causes accumulation of filamentous actin, disruption of normal epithelial organization, and defects in cell migration. Animals with less severe combinations of mutant Cfl1 and Dstn alleles, which retain one wild-type Cfl1 or Dstn allele, display abnormalities including ureter duplication, renal hypoplasia, and abnormal kidney shape. The results indicate that ADF activity, provided by either cofilin1 or destrin, is essential in UB epithelial cells for normal growth and branching.

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Disruption of actin depolymerization results in irregular ureteric epithelial cell shape and organization due to F-actin accumulation in Cfl;Dstn double mutant ureteric bud.(A–D), A transgene encoding myristoylated-Venus driven by Hoxb7-promoter was introduced to Cfl1;Dstn mutant mice to visualize ureteric epithelial cell outlines; optical sections through ureteric bud tips of control Dstn+/− (A–B) and double mutant (C–D) kidneys at E12.5. (A) and (C) are optical sections through the lumen of the UB tip, while (B) and (D) are glancing sections through the epithelium. Control ureteric epithelium shows cells that vary in shape, but have smooth outlines and are organized in an orderly pattern along the whole epithelium. (C–D), Double mutant epithelial cells are often abnormal in shape and exhibit a disorganized pattern throughout the ureteric bud. (E–H), Confocal images of phalloidin (red)/calbindin (green) double staining, which visualizes actin filaments (F-actin) in developing kidney. (E–F), In control kidney, actin filaments are enriched in apical side of ureteric epithelium while some localize to the basolateral surfaces. (G–H) Disruption of actin depolymerization in Cfl1;Dstn double mutants results in huge accumulation of F-actin, specifically in the ureteric epithelium where Cfl1F is deleted. Scale bars: 50 µm.
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pgen-1001176-g005: Disruption of actin depolymerization results in irregular ureteric epithelial cell shape and organization due to F-actin accumulation in Cfl;Dstn double mutant ureteric bud.(A–D), A transgene encoding myristoylated-Venus driven by Hoxb7-promoter was introduced to Cfl1;Dstn mutant mice to visualize ureteric epithelial cell outlines; optical sections through ureteric bud tips of control Dstn+/− (A–B) and double mutant (C–D) kidneys at E12.5. (A) and (C) are optical sections through the lumen of the UB tip, while (B) and (D) are glancing sections through the epithelium. Control ureteric epithelium shows cells that vary in shape, but have smooth outlines and are organized in an orderly pattern along the whole epithelium. (C–D), Double mutant epithelial cells are often abnormal in shape and exhibit a disorganized pattern throughout the ureteric bud. (E–H), Confocal images of phalloidin (red)/calbindin (green) double staining, which visualizes actin filaments (F-actin) in developing kidney. (E–F), In control kidney, actin filaments are enriched in apical side of ureteric epithelium while some localize to the basolateral surfaces. (G–H) Disruption of actin depolymerization in Cfl1;Dstn double mutants results in huge accumulation of F-actin, specifically in the ureteric epithelium where Cfl1F is deleted. Scale bars: 50 µm.

Mentions: Dynamic actin cytoskeleton rearrangements are involved in several cellular processes, such as apoptosis, proliferation and migration [1]. We took the advantage of the Hoxb7/myrVenus transgenic line, which expresses myristylated-Venus fluorescent protein at the cell membrane [22], to visualize epithelial cell shape and organization in the ureteric buds of Cfl1;Dstn double mutant mice. Confocal scanning of the UB epithelium at E12.5 revealed a variety of cell shapes in control kidneys, but the epithelium was well organized and cell outlines smooth and distinct (Figure 5A and 5B). In contrast, UB epithelial cells in Cfl1;Dstn mutant kidneys were disorganized, irregular in size and shape, and contained abnormal membranous (i.e., Venus-positive) bodies (Figure 5C and 5D). Thus, lack of both cofilin1 and destrin in the UB disrupts normal epithelial cell shape and organization.


Actin depolymerizing factors cofilin1 and destrin are required for ureteric bud branching morphogenesis.

Kuure S, Cebrian C, Machingo Q, Lu BC, Chi X, Hyink D, D'Agati V, Gurniak C, Witke W, Costantini F - PLoS Genet. (2010)

Disruption of actin depolymerization results in irregular ureteric epithelial cell shape and organization due to F-actin accumulation in Cfl;Dstn double mutant ureteric bud.(A–D), A transgene encoding myristoylated-Venus driven by Hoxb7-promoter was introduced to Cfl1;Dstn mutant mice to visualize ureteric epithelial cell outlines; optical sections through ureteric bud tips of control Dstn+/− (A–B) and double mutant (C–D) kidneys at E12.5. (A) and (C) are optical sections through the lumen of the UB tip, while (B) and (D) are glancing sections through the epithelium. Control ureteric epithelium shows cells that vary in shape, but have smooth outlines and are organized in an orderly pattern along the whole epithelium. (C–D), Double mutant epithelial cells are often abnormal in shape and exhibit a disorganized pattern throughout the ureteric bud. (E–H), Confocal images of phalloidin (red)/calbindin (green) double staining, which visualizes actin filaments (F-actin) in developing kidney. (E–F), In control kidney, actin filaments are enriched in apical side of ureteric epithelium while some localize to the basolateral surfaces. (G–H) Disruption of actin depolymerization in Cfl1;Dstn double mutants results in huge accumulation of F-actin, specifically in the ureteric epithelium where Cfl1F is deleted. Scale bars: 50 µm.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2965756&req=5

pgen-1001176-g005: Disruption of actin depolymerization results in irregular ureteric epithelial cell shape and organization due to F-actin accumulation in Cfl;Dstn double mutant ureteric bud.(A–D), A transgene encoding myristoylated-Venus driven by Hoxb7-promoter was introduced to Cfl1;Dstn mutant mice to visualize ureteric epithelial cell outlines; optical sections through ureteric bud tips of control Dstn+/− (A–B) and double mutant (C–D) kidneys at E12.5. (A) and (C) are optical sections through the lumen of the UB tip, while (B) and (D) are glancing sections through the epithelium. Control ureteric epithelium shows cells that vary in shape, but have smooth outlines and are organized in an orderly pattern along the whole epithelium. (C–D), Double mutant epithelial cells are often abnormal in shape and exhibit a disorganized pattern throughout the ureteric bud. (E–H), Confocal images of phalloidin (red)/calbindin (green) double staining, which visualizes actin filaments (F-actin) in developing kidney. (E–F), In control kidney, actin filaments are enriched in apical side of ureteric epithelium while some localize to the basolateral surfaces. (G–H) Disruption of actin depolymerization in Cfl1;Dstn double mutants results in huge accumulation of F-actin, specifically in the ureteric epithelium where Cfl1F is deleted. Scale bars: 50 µm.
Mentions: Dynamic actin cytoskeleton rearrangements are involved in several cellular processes, such as apoptosis, proliferation and migration [1]. We took the advantage of the Hoxb7/myrVenus transgenic line, which expresses myristylated-Venus fluorescent protein at the cell membrane [22], to visualize epithelial cell shape and organization in the ureteric buds of Cfl1;Dstn double mutant mice. Confocal scanning of the UB epithelium at E12.5 revealed a variety of cell shapes in control kidneys, but the epithelium was well organized and cell outlines smooth and distinct (Figure 5A and 5B). In contrast, UB epithelial cells in Cfl1;Dstn mutant kidneys were disorganized, irregular in size and shape, and contained abnormal membranous (i.e., Venus-positive) bodies (Figure 5C and 5D). Thus, lack of both cofilin1 and destrin in the UB disrupts normal epithelial cell shape and organization.

Bottom Line: The actin depolymerizing factors (ADFs) play important roles in several cellular processes that require cytoskeletal rearrangements, such as cell migration, but little is known about the in vivo functions of ADFs in developmental events like branching morphogenesis.Lack of Cfl1 and Dstn in the UB causes accumulation of filamentous actin, disruption of normal epithelial organization, and defects in cell migration.The results indicate that ADF activity, provided by either cofilin1 or destrin, is essential in UB epithelial cells for normal growth and branching.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America.

ABSTRACT
The actin depolymerizing factors (ADFs) play important roles in several cellular processes that require cytoskeletal rearrangements, such as cell migration, but little is known about the in vivo functions of ADFs in developmental events like branching morphogenesis. While the molecular control of ureteric bud (UB) branching during kidney development has been extensively studied, the detailed cellular events underlying this process remain poorly understood. To gain insight into the role of actin cytoskeletal dynamics during renal branching morphogenesis, we studied the functional requirements for the closely related ADFs cofilin1 (Cfl1) and destrin (Dstn) during mouse development. Either deletion of Cfl1 in UB epithelium or an inactivating mutation in Dstn has no effect on renal morphogenesis, but simultaneous lack of both genes arrests branching morphogenesis at an early stage, revealing considerable functional overlap between cofilin1 and destrin. Lack of Cfl1 and Dstn in the UB causes accumulation of filamentous actin, disruption of normal epithelial organization, and defects in cell migration. Animals with less severe combinations of mutant Cfl1 and Dstn alleles, which retain one wild-type Cfl1 or Dstn allele, display abnormalities including ureter duplication, renal hypoplasia, and abnormal kidney shape. The results indicate that ADF activity, provided by either cofilin1 or destrin, is essential in UB epithelial cells for normal growth and branching.

Show MeSH
Related in: MedlinePlus