Project description:Bone morphogenetic protein 4 (BMP4) is essential for lung development. To define its intracellular signaling mechanisms by which BMP4 regulates lung development, BMP-specific Smad1 or Smad5 was selectively knocked out in fetal mouse lung epithelial cells. Abrogation of lung epithelial-specific Smad1, but not Smad5, resulted in retardation of lung branching morphogenesis and reduced sacculation, accompanied by altered distal lung epithelial cell proliferation and differentiation, and consequently severe neonatal respiratory failure. By combining cDNA microarray with ChIP-chip analyses, Wnt inhibitory factor-1 (Wif1) was identified as a novel target gene of Smad1 in the developing mouse lung epithelial cells. Loss of Smad1 transcriptional activation of Wif1 expression was associated with reduced Wif1 expression and increased Wnt/beta-catenin signaling activity in lung epithelia, resulting in specific fetal lung abnormalities. Therefore, a novel regulatory loop of BMP4-Smad1-Wif1-Wnt/beta-catenin in coordinating BMP and Wnt pathways to control fetal lung development is suggested. mRNA profiling: Total RNA was isolated from left lobe lungs of three pair of E18.5 wild type and Smad1 lung epithelium-specific conditional knockout mice
Project description:Bone morphogenetic protein 4 (BMP4) is essential for lung development. To define its intracellular signaling mechanisms by which BMP4 regulates lung development, BMP-specific Smad1 or Smad5 was selectively knocked out in fetal mouse lung epithelial cells. Abrogation of lung epithelial-specific Smad1, but not Smad5, resulted in retardation of lung branching morphogenesis and reduced sacculation, accompanied by altered distal lung epithelial cell proliferation and differentiation, and consequently severe neonatal respiratory failure. By combining cDNA microarray with ChIP-chip analyses, Wnt inhibitory factor-1 (Wif1) was identified as a novel target gene of Smad1 in the developing mouse lung epithelial cells. Loss of Smad1 transcriptional activation of Wif1 expression was associated with reduced Wif1 expression and increased Wnt/beta-catenin signaling activity in lung epithelia, resulting in specific fetal lung abnormalities. Therefore, a novel regulatory loop of BMP4-Smad1-Wif1-Wnt/beta-catenin in coordinating BMP and Wnt pathways to control fetal lung development is suggested.
Project description:Digestive system development is orchestrated by combinatorial signaling interactions between endoderm and mesoderm, but how they are integrated in the genome is poorly understood. Here we identified the Xenopus foregut and hindgut progenitor transcriptomes, which are largely conserved with mammals. Using RNA-seq and ChIP-seq we show that BMP/Smad1 regulates dorsal-ventral gene expression in both the endoderm and mesoderm, whereas Wnt/b-catenin acts as a genome-wide toggle between foregut and hindgut programs. In addition to b-catenin-Tcf promoting hindgut gene transcription, we unexpectedly observed Wnt-repressed foregut genes associated with b-catenin-binding to DNA lacking Tcf motifs, suggesting a novel direct repression. We define how BMP and Wnt signaling are integrated in the genome with Smad1 and β-catenin co-occupying DNA elements associated with hundreds of key regulatory genes. These results extend our understanding of GI organogenesis and how Wnt and BMP may coordinate genomic responses in other contexts.
Project description:Digestive system development is orchestrated by combinatorial signaling interactions between endoderm and mesoderm, but how they are integrated in the genome is poorly understood. Here we identified the Xenopus foregut and hindgut progenitor transcriptomes, which are largely conserved with mammals. Using RNA-seq and ChIP-seq we show that BMP/Smad1 regulates dorsal-ventral gene expression in both the endoderm and mesoderm, whereas Wnt/b-catenin acts as a genome-wide toggle between foregut and hindgut programs. In addition to b-catenin-Tcf promoting hindgut gene transcription, we unexpectedly observed Wnt-repressed foregut genes associated with b-catenin-binding to DNA lacking Tcf motifs, suggesting a novel direct repression. We define how BMP and Wnt signaling are integrated in the genome with Smad1 and β-catenin co-occupying DNA elements associated with hundreds of key regulatory genes. These results extend our understanding of GI organogenesis and how Wnt and BMP may coordinate genomic responses in other contexts.
Project description:This SuperSeries is composed of the following subset Series: GSE29193: Genome-wide location analysis of BMP (SMAD1) in mouse erythroid progenitors co-occupted with lineage specific regulators (GATA1, GATA2) GSE29194: Genome-wide location analysis of WNT (Tcf7l2) and BMP (SMAD1) in human hematopoeitic progenitors co-occupied with lineage specific regulators (GATA1, GATA2) GSE29195: Genome-wide location analysis of WNT (Tcf7l2) and BMP (SMAD1) in human hematopoeitic cell lines co-occupied with lineage specific regulators (GATA1, GATA2, CEBPA) Refer to individual Series
Project description:Branching morphogenesis is essential for the successful development of a functional lung to accomplish its gas exchange function. Although many studies have highlighted requirements for the bone morphogenetic protein (BMP) signaling pathway during branching morphogenesis, little is known about how BMP signalingis regulated. Here we report that the protein arginine methyltransferase 5 (Prmt5) and symmetric dimethylation at histone H4 arginine 3 (H4R3sme2) directly associate with chromatin of Bmp4 to suppress its transcription. Inactivation of Prmt5 in the lung epithelium results in halted branching morphogenesis, altered epithelial cell differentiation and neonatal lethality. These defects are accompanied by increased apoptosis and reduced proliferation of lung epithelium, as a consequence of elevated canonical BMP-Smad1/5/9 signaling. Inhibition of BMP signaling by Noggin rescues the lung branching defects of Prmt5 mutant in vitro. Taken together, our results identify a novel mechanism through which Prmt5-mediated histone arginine methylation represses canonical BMP signaling to regulate lung branching morphogenesis.
Project description:The BMP signaling pathway regulates multiple steps of hematopoiesis, mediated through receptor-regulated Smads, including Smad1 and Smad5. Here we use loss-of-function approaches in zebrafish to compare the roles of Smad1 and Smad5 during embryonic hematopoiesis. Microarray experiments revealed that the two proteins regulate redundantly the key initiators of the hemato-vascular program, including scl, lmo2, and gfi1. However, each also regulates a remarkably distinct genetic program, with Smad5 uniquely regulating the BMP signaling pathway itself. Our results suggest that specificity of BMP signaling output, with respect to hematopoiesis, can be explained by differential functions of Smad1 and Smad5. Keywords: Gene expression transcript profiles
Project description:The tightly controlled BMP-Smad1 pathway is essential for embryonic development and postnatal tissue homeostasis. Dysfunction of BMP-Smad1 signaling also leads to tumor development such as juvenile polyposis and Cowden syndromes and various tumors in mouse models, with unknown pathological mechanisms. Here we establish a link between the BMP-Smad pathway and the prominent tumor suppressor Atm-p53 pathway. We identify activated nuclear Smad1 as an Atm substrate under genotoxic stress. Atm-mediated Smad1 S239 phosphorylation disrupts Smad1 interaction with protein phosphatase PPM1A and enhances Smad1 activation and up-regulation, which not only turns on target genes including Cdk1nc but also interacts with p53 and inhibits Mdm2-mediated p53 ubiquitination, leading to p53 stabilization. Functionally, Smad1 acts like a tumor suppressor in DNA damage response, cell transformation and tumorigenesis in a p53-dependent manner. Sequencing of the gastric cancer samples revealed that Smad1 is frequently mutated, with S239 as mutational hotspot. This study thus establishes the BMP-Smad1 pathway as an integral part of DNA damage response, which can suppresses tumorigenesis via p53. Transformed MEFs (Smad1f/f, Smad1f/f Cre) treated with 50ng/ml BMP2, 1 ug/ml doxorubincin, or both for different periods of time. The mRNA levels of all genes were compared using microarray analysis.
Project description:The dorsoventral gradient of BMP signaling plays an essential role in embryonic patterning, with high BMP signal activating ventral-lateral mesoderm markers directly, and low BMP signal inducing neural tissues. The Zinc finger SWIM domain-containing protein 4 (zswim4) is expressed in the dorsal blastopore lip at the onset of Xenopus gastrula and then enriched at the forming neuroectoderm at mid-gastrula stages. Overexpression of zswim4 in Xenopus embryos causes inhibition of the anterior axis and shortened, curved body, and knockdown or knockout of zswim4 disturbed embryonic body axis formation and head development. The expression of ventral-lateral mesoderm marker genes was reduced after zswim4 overexpression and increased in embryos with zswim4 knockdown. Neural marker genes were repressed in zswim4 morphant. Mechanistically Zswim4 attenuates BMP signal through reducing protein stability of Smad1 in both Xenopus embryos and HEK293T cells. Zswim4 interacts with Smad1 and promotes ubiquitination of Smad1 in HEK293T cells. To identify the interaction partner of Zswim4 in regulating Smad1 stability, we performed SILAC based IP in HEK293T cells, and the precipitates were analyzed by Mass Spectrometry.
Project description:The tightly controlled BMP-Smad1 pathway is essential for embryonic development and postnatal tissue homeostasis. Dysfunction of BMP-Smad1 signaling also leads to tumor development such as juvenile polyposis and Cowden syndromes and various tumors in mouse models, with unknown pathological mechanisms. Here we establish a link between the BMP-Smad pathway and the prominent tumor suppressor Atm-p53 pathway. We identify activated nuclear Smad1 as an Atm substrate under genotoxic stress. Atm-mediated Smad1 S239 phosphorylation disrupts Smad1 interaction with protein phosphatase PPM1A and enhances Smad1 activation and up-regulation, which not only turns on target genes including Cdk1nc but also interacts with p53 and inhibits Mdm2-mediated p53 ubiquitination, leading to p53 stabilization. Functionally, Smad1 acts like a tumor suppressor in DNA damage response, cell transformation and tumorigenesis in a p53-dependent manner. Sequencing of the gastric cancer samples revealed that Smad1 is frequently mutated, with S239 as mutational hotspot. This study thus establishes the BMP-Smad1 pathway as an integral part of DNA damage response, which can suppresses tumorigenesis via p53.