The flow responsive transcription factor Klf2 is required for myocardial wall integrity by modulating Fgf signaling
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PROVIDER: PRJNA503817 | ENA |
REPOSITORIES: ENA
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Project description:Complex interplay between cardiac tissues is crucial for their integrity. The flow responsive transcription factor KLF2, which is expressed in the endocardium, is vital for cardiovascular development but its exact role remains to be defined. To this end, we mutated both klf2 paralogues in zebrafish, and while single mutants exhibit no obvious phenotypes, double mutants display a novel phenotype of cardiomyocyte extrusion towards the abluminal side. This extrusion requires cardiac contractility and correlates with the mislocalization of N-cadherin from the lateral to the apical side of cardiomyocytes. Transgenic rescue data show that klf2 expression in endothelium, but not myocardium, can rescue this cardiomyocyte extrusion phenotype. Transcriptome analysis of klf2 mutant hearts reveals that Fgf signaling is affected, and accordingly, we find that inhibition of Fgf signaling in wild-type animals leads to abluminal cardiomyocyte extrusion. These studies provide new insights into how Klf2 regulates cardiovascular development and specifically myocardial wall integrity.
2019-01-10 | GSE122137 | GEO
Project description:Complex interplay between cardiac tissues is crucial for their integrity. The flow responsive transcription factor KLF2, which is expressed in the endocardium, is vital for cardiovascular development but its exact role remains to be defined. To this end, we mutated both klf2 paralogues in zebrafish, and while single mutants exhibit no obvious phenotype, double mutants display a novel phenotype of cardiomyocyte extrusion towards the abluminal side. This extrusion requires cardiac contractility and correlates with the mislocalization of N-cadherin from the lateral to the apical side of cardiomyocytes. Transgenic rescue data show that klf2 expression in endothelium, but not myocardium, prevents this cardiomyocyte extrusion phenotype. Transcriptome analysis of klf2 mutant hearts reveals that Fgf signaling is affected, and accordingly, we find that inhibition of Fgf signaling in wild-type animals can lead to abluminal cardiomyocyte extrusion. These studies provide new insights into how Klf2 regulates cardiovascular development and specifically myocardial wall integrity.
| S-EPMC6329608 | biostudies-literature
Project description:The shear stress-induced transcription factor Krüppel-like factor 2 (KLF2) confers anti-inflammatory properties to endothelial cells through inhibition of activator protein 1, presumably by interfering with MAPK cascades. To gain insight into the regulation of these cascades by KLF2, we used antibody arrays in combination with time-course mRNA micro-array analysis. No gross changes in MAPKs were detected, rather phosphorylation of actin cytoskeleton-associated proteins, including Focal Adhesion Kinase, was markedly repressed by KLF2. Furthermore, we demonstrate that KLF2-mediated inhibition of Jun NH2-terminal kinase (JNK) and its downstream targets ATF2/c-Jun is dependent on the cytoskeleton. Specifically, KLF2 directs the formation of typical short basal actin filaments, we term shear fibers, which are distinct from thrombin- or TNF-α-induced stress fibers. KLF2 is shown to be essential for shear stress-induced cell alignment, concomitant shear fiber assembly and inhibition of JNK signaling. These findings link the specific effects of shear-induced KLF2 on endothelial morphology to the suppression of JNK MAPK signaling in vascular homeostasis via novel actin shear fibers. Tramscriptome profiling: Three independent isolates of Human Umbilical Vein Endothelial cells were transduced with lentiviral vectors expressing Kruppel Like Factor 2 (KLF2) or no protein (mock), and at time after transduction 24 h, 48 h, 72 h , RNA was isolated and hybridized to GPL4868 microarrays using dye swap procedure Kinome profiling: Two independent isolates of Human Umbilical Vein Endothelial cells were transduced with lentiviral vectors expressing Kruppel Like Factor 2 (KLF2) or no protein (mock), and at time after transduction 72 h , total cellular protein was isolated and hybridized to Kinexus KAM-1.1 phosphoprotein (kinexus) microarrays using dual color procedure in duplicate
2010-06-25 | E-GEOD-19412 | biostudies-arrayexpress
Project description:The shear stress-induced transcription factor Krüppel-like factor 2 (KLF2) confers anti-inflammatory properties to endothelial cells through inhibition of activator protein 1, presumably by interfering with MAPK cascades. To gain insight into the regulation of these cascades by KLF2, we used antibody arrays in combination with time-course mRNA micro-array analysis. No gross changes in MAPKs were detected, rather phosphorylation of actin cytoskeleton-associated proteins, including Focal Adhesion Kinase, was markedly repressed by KLF2. Furthermore, we demonstrate that KLF2-mediated inhibition of Jun NH2-terminal kinase (JNK) and its downstream targets ATF2/c-Jun is dependent on the cytoskeleton. Specifically, KLF2 directs the formation of typical short basal actin filaments, we term shear fibers, which are distinct from thrombin- or TNF-α-induced stress fibers. KLF2 is shown to be essential for shear stress-induced cell alignment, concomitant shear fiber assembly and inhibition of JNK signaling. These findings link the specific effects of shear-induced KLF2 on endothelial morphology to the suppression of JNK MAPK signaling in vascular homeostasis via novel actin shear fibers.
2009-12-11 | GSE19412 | GEO
Project description:Maintenance of vascular integrity in the adult animal is needed for survival and critically dependent on the endothelial lining, which controls barrier function, blood fluidity, and flow dynamics. However, nodal regulators that coordinate endothelial identity and function in the adult animal remain poorly characterized. Here we show that endothelial KLF2 and KLF4 control a large segment of the endothelial transcriptome thereby affecting virtually all key endothelial functions. Inducible endothelial-specific deletion of Klf2 and/or Klf4 reveals that a single allele of either gene is sufficient for survival, but absence of both (EC-DKO) results in acute death from myocardial infarction, heart failure, and stroke. EC-DKO animals exhibit profound compromise in vascular integrity and profound dysregulation of the coagulation system. Collectively, these studies establish an absolute requirement for KLF2/4 for maintenance of endothelial and vascular integrity in the adult animal.
2017-03-01 | GSE92965 | GEO
Project description:The self-renewing pluripotent state was first captured in mouse embryonic stem cells (mESCs) over two decades ago. The standard condition requires the presence of serum and LIF, which provide growth promoting signals for cell expansion. However, there are pro-differentiation signals which destabilize the undifferentiated state of mESCs. The dual inhibition (2i) of the pro-differentiation Mek/Erk and Gsk3/Tcf3 pathways in mESCs is sufficient to establish an enhanced pluripotent “ground state” which bears features resembling the pre-implantation mouse epiblast. Gsk3 inhibition alleviates the repression of Esrrb, a transcription factor that can substitute for Nanog function in mESCs. The molecular mechanism that is mediated by Mek inhibition is however not clear. In this study, we investigate the pathway through which Mek inhibition operates to maintain ground state pluripotency. We have found that in mESCs, Kruppel-like factor 2 (Klf2) is a protein target of the Mek/Erk pathway; and that Klf2 protein is phosphorylated by Erk2 and subsequently degraded through the proteosome. It is therefore by Mek-inhibition through PD0325901 or 2i that enables the stabilization and accumulation of Klf2 to sustain ground state pluripotency. Importantly, we found that Klf2-null mESCs, while viable under LIF/Serum conditions, cannot be maintained and eventually gradually die within a few passages. Our result thus demonstrates that Klf2 is an essential factor of ground state pluripotency. Collectively, our study defines the Mek/Klf2 axis that cooperates with the Gsk3/Esrrb pathway in mediating ground state pluripotency.
2014-06-04 | E-MTAB-2366 | biostudies-arrayexpress
Project description:KLF2 is a Krüppel-like zinc-finger transcription factor required for blood vessel, lung, T-cell, and erythroid development. KLF2-/- mice die by embryonic day 14.5 (E14.5), due to hemorrhaging and heart failure. Embryonic -like globin gene expression is reduced in KLF2-/- embryos compared to wildtype (WT), and E10.5 erythroid cells exhibit abnormal morphology. Other KLF2 target genes were identified by comparing E9.5 KLF2-/- and WT yolk sac erythroid cells, using laser capture microdissection and microarray assays. One hundred and ninety-six genes exhibited significant differences in expression; eighty-nine of these are downregulated in KLF2-/- compared to WT. Genes involved in cell migration, differentiation and development are over-represented in the KLF2-regulated gene list. Previously identified erythroid-enriched regulatory genes such as reelin, adenylate cyclase 7, cytotoxic T lymphocyte-associated protein 2 alpha, and CD24a antigen are downregulated in KLF2-/- compared to WT. SOX2, a pluripotency factor in ES cells, is also a KLF2 target in embryonic erythroid cells. We investigated whether reelin, which has an established role in neuronal migration and proliferation, has a role in embryonic erythropoiesis. Luciferase reporter assays demonstrated that KLF2 directly transactivates the reelin promoter, but reelin mutant mice have no apparent abnormalities in embryonic erythroid morphology or globin gene expression. Timed-pregnant KLF2+/- females were anesthetized and sacrificed. E9.5 yolk sacs were dissected from the embryo, cryoprotected in 20% sucrose in PBS and frozen in OCT media. A small portion of the embryo tail was used for PCR genotyping. Eight micron KLF2-/- frozen yolk sac sections were obtained and laser capture microdissection (LCM) was used to isolate primitive erythroid precursors. For each biological replicate, 2 to 4 yolk sacs from 2 different litters were used. Total RNA was isolated from 4 different KLF2-/- erythroid samples and hybridized to Affymetrix 430 A 2.0 microarrays
2011-03-02 | E-GEOD-27602 | biostudies-arrayexpress
Project description:KLF2 is a Krüppel-like zinc-finger transcription factor required for blood vessel, lung, T-cell, and erythroid development. KLF2-/- mice die by embryonic day 14.5 (E14.5), due to hemorrhaging and heart failure. Embryonic -like globin gene expression is reduced in KLF2-/- embryos compared to wildtype (WT), and E10.5 erythroid cells exhibit abnormal morphology. Other KLF2 target genes were identified by comparing E9.5 KLF2-/- and WT yolk sac erythroid cells, using laser capture microdissection and microarray assays. One hundred and ninety-six genes exhibited significant differences in expression; eighty-nine of these are downregulated in KLF2-/- compared to WT. Genes involved in cell migration, differentiation and development are over-represented in the KLF2-regulated gene list. Previously identified erythroid-enriched regulatory genes such as reelin, adenylate cyclase 7, cytotoxic T lymphocyte-associated protein 2 alpha, and CD24a antigen are downregulated in KLF2-/- compared to WT. SOX2, a pluripotency factor in ES cells, is also a KLF2 target in embryonic erythroid cells. We investigated whether reelin, which has an established role in neuronal migration and proliferation, has a role in embryonic erythropoiesis. Luciferase reporter assays demonstrated that KLF2 directly transactivates the reelin promoter, but reelin mutant mice have no apparent abnormalities in embryonic erythroid morphology or globin gene expression.
2011-03-02 | GSE27602 | GEO
Project description:On triggering of the T cell receptor CD8 T lymphocytes downregulate expression of the transcription factor KLF2. KLF2 expression remains low as these cells differentiate to Cytotoxic T lymphocytes (CTL) but may be re-expressed depending on the local environmental signals. We used retroviral transduction to enforce KLF2 expression in CTL to determine the impact of it re-expression on the CTL genetic program. T lymphocytes with a transgenic T cell receptor (P14 LCMV) isolated from murine spleens were activated with gp33-41 peptide for 2 days and transduced with empty vector (evGFP) or GFP-KLF2. After differentiation to CTL in culture with Interleukin-2 for 2 further days, cells positive for GFP were isolated by Fluorescence Activated Cell Sorting and the RNA extracted for microarray analysis.
2013-05-31 | E-GEOD-26568 | biostudies-arrayexpress
Project description:On triggering of the T cell receptor CD8 T lymphocytes downregulate expression of the transcription factor KLF2. KLF2 expression remains low as these cells differentiate to Cytotoxic T lymphocytes (CTL) but may be re-expressed depending on the local environmental signals. We used retroviral transduction to enforce KLF2 expression in CTL to determine the impact of it re-expression on the CTL genetic program.
2013-05-31 | GSE26568 | GEO