Cardiac Defects Associated with the Absence of the Platelet-derived Growth Factor α Receptor in the Patch Mouse

2001 ◽  
Vol 7 (1) ◽  
pp. 56-65
Author(s):  
Robert L. Price ◽  
Thomas E. Thielen ◽  
Thomas K. Borg ◽  
Louis Terracio
Keyword(s):  
Growth Factor ◽  
Cardiac Myocytes ◽  
Heart Development ◽  
Cardiac Development ◽  
Outflow Tract ◽  
Cytoskeletal Proteins ◽  
Platelet Derived Growth Factor ◽  
Mouse Heart ◽  
Littermate Control ◽  
Naturally Occurring

AbstractIn this report, we describe the distribution of the platelet-derived growth factor receptor α (PDGFRα) by immunolocalization in the embryonic day 10.5 mouse heart and defects in heart development associated with the absence of this receptor in the Patch mouse. The Patch mouse is a naturally occurring mutant that has been accepted as a model for determining the role of the PDGFRα in early cardiac development. Even though other genetic defects exist in this naturally occurring mutant, most defects associated with cardiac development are believed to be a result of the absence of this receptor. Gross morphological defects including improper septation of the outflow tract, dysmorphic shape of the heart, and lack of trabecular development are similar to those that have been previously described. Many of these defects have been attributed to the failure of a subset of non-neuronal neural crest cells to properly migrate into the region of the developing outflow tract. In these studies, we have also used confocal scanning laser and transmission electron microscopy to describe and compare the organization and differentiation of the cytoskeletal proteins actin and myosin in littermate control and Patch mouse hearts. Cytoskeletal organization of the cardiac myocytes in Patch mouse hearts has not previously been described. In most cardiac myocytes of Patch mice, actin was found only on the periphery of the cells, and the organization of actin, myosin, and precursor Z-band material into distinct myofibrils was greatly reduced.

Abstract 124: Function of the Cytoskeletal Proteins Alpha-catenins in Myocardial Growth Control

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Jifen Li ◽  
Sarah Carrante ◽  
Roslyn Yi ◽  
Frans van Roy ◽  
Glenn L. Radice
Keyword(s):  
Heart Development ◽  
Growth Control ◽  
Cytoskeletal Proteins ◽  
Neonatal Rat ◽  
Nuclear Accumulation ◽  
Mouse Heart ◽  
Cardiomyocyte Proliferation ◽  
Rat Cardiomyocytes ◽  
Neonatal Cardiomyocytes

Introduction: Mammalian heart possesses regenerative potential immediately after birth and lost by one week of age. The mechanisms that govern neonatal cardiomyocyte proliferation and regenerative capacity are poorly understood. Recent reports indicate that Yap-Tead transcriptional complex is necessary and sufficient for cardiomyocyte proliferation. During postnatal development, N-cadherin/catenin adhesion complex becomes concentrated at termini of cardiomyocytes facilitating maturation of a specialized intercellular junction structure, the intercalated disc (ICD). This process coincides with the time cardiomyocytes exit cell cycle soon after birth. Hypothesis: We hypothesize that coincident with maturation of ICD α-catenins sequester transcriptional coactivator Yap in cytosol thus preventing activation of genes critical for cardiomyocyte proliferation. Methods: We deleted αE-catenin / αT-catenin genes (α-cat DKO) in perinatal mouse heart and knockdown (KD) α-catenins in neonatal rat cardiomyocytes to study functional impact of α-catenins ablation on ICD maturation. Results: We previously demonstrated that adult α-cat DKO mice exhibited decrease in scar size and improved function post myocardial infarction. In present study, we investigated function of α-catenins during postnatal heart development. We found increase in the number of Yap-positive nuclei (58.7% in DKO vs. 35.8 % in WT, n=13, p<0.001) and PCNA (53.9% in DKO vs. 47.8%, n=8, p<0.05) at postnatal day 1 and day 7 of α-cat DKO heart, respectively. Loss of α-catenins resulted in reduction in N-cadherin at ICD at day 14. We observed an increase number of mononucleated myocytes and decrease number of binucleated myocytes in α-cat DKO compared to controls. Using siRNA KD, we were able to replicate α-cat DKO proliferative phenotype in vitro. The number of BrdU-positive cells was decreased in α-cat KD after interfering with Yap expression (2.91% in α-cat KD vs. 2.02% in α-cat/Yap KD, n>2500 cells, p<0.05), suggesting α-catenins regulate cell proliferation through Yap in neonatal cardiomyocytes. Conclusion: Our results suggest that maturation of ICD regulates α-catenin-Yap interactions in cytosol, thus preventing Yap nuclear accumulation and cardiomyocyte proliferation.

The cardiac homeobox gene Csx/Nkx2.5 lies genetically upstream of multiple genes essential for heart development

Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1269-1280 ◽  
Author(s):  
M. Tanaka ◽  
Z. Chen ◽  
S. Bartunkova ◽  
N. Yamasaki ◽  
S. Izumo
Keyword(s):  
Cardiac Myocytes ◽  
Heart Development ◽  
Cardiac Development ◽  
Es Cells ◽  
Homeobox Gene ◽  
Yolk Sac ◽  
Tunel Staining ◽  
Mesoderm Specification ◽  
Developing Heart ◽  
Heart Looping

Csx/Nkx2.5 is a vertebrate homeobox gene with a sequence homology to the Drosophila tinman, which is required for the dorsal mesoderm specification. Recently, heterozygous mutations of this gene were found to cause human congenital heart disease (Schott, J.-J., Benson, D. W., Basson, C. T., Pease, W., Silberbach, G. M., Moak, J. P., Maron, B. J., Seidman, C. E. and Seidman, J. G. (1998) Science 281, 108–111). To investigate the functions of Csx/Nkx2.5 in cardiac and extracardiac development in the vertebrate, we have generated and analyzed mutant mice completely null for Csx/Nkx2.5. Homozygous null embryos showed arrest of cardiac development after looping and poor development of blood vessels. Moreover, there were severe defects in vascular formation and hematopoiesis in the mutant yolk sac. Interestingly, TUNEL staining and PCNA staining showed neither enhanced apoptosis nor reduced cell proliferation in the mutant myocardium. In situ hybridization studies demonstrated that, among 20 candidate genes examined, expression of ANF, BNP, MLC2V, N-myc, MEF2C, HAND1 and Msx2 was disturbed in the mutant heart. Moreover, in the heart of adult chimeric mice generated from Csx/Nkx2.5 null ES cells, there were almost no ES cell-derived cardiac myocytes, while there were substantial contributions of Csx /Nkx2.5-deficient cells in other organs. Whole-mount β-gal staining of chimeric embryos showed that more than 20% contribution of Csx/Nkx2. 5-deficient cells in the heart arrested cardiac development. These results indicate that (1) the complete null mutation of Csx/Nkx2.5 did not abolish initial heart looping, (2) there was no enhanced apoptosis or defective cell cycle entry in Csx/Nkx2.5 null cardiac myocytes, (3) Csx/Nkx2.5 regulates expression of several essential transcription factors in the developing heart, (4) Csx/Nkx2.5 is required for later differentiation of cardiac myocytes, (5) Csx/Nkx2. 5 null cells exert dominant interfering effects on cardiac development, and (6) there were severe defects in yolk sac angiogenesis and hematopoiesis in the Csx/Nkx2.5 null embryos.

scholarly journals Divergent Roles of c-Src in Controlling Platelet-derived Growth Factor-dependent Signaling in Fibroblasts

2005 ◽  
Vol 16 (11) ◽  
pp. 5418-5432 ◽  
Author(s):  
Kavita Shah ◽  
Fabien Vincent
Keyword(s):  
Growth Factor ◽  
Cellular Level ◽  
Cytoskeletal Proteins ◽  
Platelet Derived Growth Factor ◽  
Transcriptional Analysis ◽  
Phosphatidylinositol 3 Kinase ◽  
Actin Reorganization ◽  
Downstream Signaling ◽  
Chemical Genetic ◽  
Considerable Controversy

The vast complexity of platelet-derived growth factor (PDGF)-induced downstream signaling pathways is well known, but the precise roles of critical players still elude us due to our lack of specific and temporal control over their activities. Accordingly, although Src family members are some of the better characterized effectors of PDGFβ signaling, considerable controversy still surrounds their precise functions. To address these questions and limitations, we applied a chemical–genetic approach to study the role of c-Src at the cellular level, in defined signaling cascades; we also uncovered novel phosphorylation targets and defined its influence on transcriptional events. The spectacular control of c-Src on actin reorganization and chemotaxis was delineated by global substrate labeling and transcriptional analysis, revealing multiple cytoskeletal proteins and chemotaxis promoting genes to be under c-Src control. Additionally, this tool revealed the contrasting roles of c-Src in controlling DNA synthesis, where it transmits conflicting inputs via the phosphatidylinositol 3 kinase and Ras pathways. Finally, this study reveals a mechanism by which Src family kinases may control PDGF-mediated responses both at transcriptional and translational levels.

Abstract 311: Opposing Roles TCF7/LEF1 and TCF7L2 in Wnt/β-Catenin and BMP Signaling During Late Heart Development

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Bo Ye ◽  
Haodong Xu ◽  
Faqian Li
Keyword(s):  
Heart Development ◽  
Target Genes ◽  
Cardiac Development ◽  
Mrna Level ◽  
Mesenchymal Cells ◽  
Bmp Signaling ◽  
Mouse Heart ◽  
Mrna Levels ◽  
Nuclear Staining ◽  
Cyclin D2

T-cell factor (TCF) and lymphoid enhancer factor (LEF) family transcriptional factors are important nuclear mediators of Wnt/β-catenin signaling. Their roles in cardiac development and diseases remain to be determined. We found that these TCF/LEF family members, including LEF1, TCF7, TCF7L1, and TCF7L2 had unique expression pattern during mouse heart development. At embryonic day (E) 13.5, LEF1 was one of the most abundant TCF/LEF members at mRNA level in the murine heart. By immunohistochemical staining, mesenchymal cells in valvular regions had much stronger intensity of LEF1 than cardiomyocytes in ventricles. Cardiomyocytes with weak to moderate nuclear staining for LEF1 were scattered in compact and trabecular layers. At E17.5, LEF1 mRNA levels dropped dramatically and its protein was no longer detected in cardiomyocytes. TCF7L1 mRNA levels also decreased from E13.5 to E17.5. Weak cytoplasmic, but not nuclear TCF7L1 signal was detected in cardiomyocytes at E13.5 by immunochemistry. TCF7 mRNA was the lowest among all four TCF/LEF members at E13.5 and it further decreased at E17.5. TCF7 protein was only detected by immunohistochemistry in mesothelial and endothelial cells, but not in cardiomyocytes or mesenchymal cells. TCF7L2 mRNA became the most abundant TCF/LEFs at E17.5. Immunolocalization revealed that TCF7L2 formed an intensity gradient with the highest levels at the inner trabecular layer, opposite to the distribution of β-catenin. Wnt signaling activation by cardiac deletion of adenomatosis polyposis coli ( Apc ), a negative Wnt regulator, led to a dramatic increase in cyclin D2, Bmp4, LEF1, and TCF7. BMP mediators, SMAD1/5/8, were increasingly phosphorylated. Chromatin immunoprecipitation revealed that TCF7L2 was removed from and replaced by LEF1 and TCF7 in the promoter of cyclin D2 and Bmp4 to promote β-catenin recruitment. Furthermore, there was co-occupancy of TCF/LEF and SMAD in the adjacent TCF/LEF and SMAD binding sites of Wnt target genes. Finally, we proved that TCF7L2 was a transcriptional suppressor of cyclin D2 and Bmp 4 in a cardiac cell line by overexpression and knockdown experiments. Our results indicate that TCF7L2 is transcriptional repressor of Wnt/β-Catenin pathway in the heart.

Platelet-derived growth factor-BB phosphorylates heat shock protein 27 in cardiac myocytes

2004 ◽  
Vol 91 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Motoki Takenaka ◽  
Hiroyuki Matsuno ◽  
Akira Ishisaki ◽  
Keiichi Nakajima ◽  
Kouseki Hirade ◽  
...  
Keyword(s):  
Growth Factor ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Cardiac Myocytes ◽  
Heat Shock Protein 27 ◽  
Platelet Derived Growth Factor

scholarly journals Platelet-Derived Growth Factor-AB Promotes the Generation of Adult Bone Marrow–Derived Cardiac Myocytes

2004 ◽  
Vol 94 (5) ◽  
Author(s):  
Munira Xaymardan ◽  
Lilong Tang ◽  
Leze Zagreda ◽  
Benedetta Pallante ◽  
Jingang Zheng ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Growth Factor ◽  
Cardiac Myocytes ◽  
Platelet Derived Growth Factor ◽  
Adult Bone Marrow ◽  
Adult Bone

Microscopy as a Tool in Understanding the Role of Growth Factors in Cardiac Development

1999 ◽  
Vol 5 (S2) ◽  
pp. 1082-1083
Author(s):  
Robert L. Price ◽  
Thomas E. Thielen ◽  
Thomas K. Borg ◽  
Louis Terracio
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Normal Development ◽  
Cardiac Development ◽  
The Past ◽  
Naturally Occurring ◽  
Temporal And Spatial ◽  
Valve Formation ◽  
Factor Function

Over the past several years the central roles of several different growth factors in the normal development of the embryonic heart have been identified through a variety of techniques involving microscopy. Initially, most studies consisted of descriptions of gross changes in cardiac morphology associated with naturally occurring mutations that affected growth factor function. More recently the development of specific probes for growth factor receptors that can be used in confocal microscopy have aided in the identification of changes in the temporal and spatial distributions of receptors at various stages of development. The correlation of these changes with developmental events such as valve formation and trabeculation in the heart, in conjunction with biochemical studies and blocking agents for the growth factors have significantly increased our understanding of growth factor function in cardiac development.

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