Microarray analysis of gene expression profiles in Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre placentas
Ontology highlight
ABSTRACT: The mammalian genome contains two ERK/MAP kinase kinase genes, Map2k1 and Map2k2, encoding dual-specificity kinases responsible for ERK/MAP kinase activation. Loss of Map2k1 function in mouse causes embryonic lethality due to placental defects, while Map2k2 mutant mice survive with a normal lifespan. The Map2k1 mutation interferes with the growth of the labyrinthine region of the placenta and its vascularization. Map2k1+/-Map2k2+/- embryos also die during gestation of underdevelopment of the labyrinth. In Map2k1+/-Map2k2+/- mutants, the vascularization of the labyrinth is reduced and defects in SynT-II formation lead to the accumulation of multinucleated trophoblasts giant cells (MTG). Deletion of both Map2k1 alleles in allantoïs-derived tissues in Map2k1+/ Map2k2+/- placenta (Map2k1flox/-Map2k2+/-Tg+/Sox2Cre) increases the penetrance and the expressivity of the MTG placental phenotype. Microarray analysis with RNA extracted from placentas of E12.5 wt, Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos was performed to evaluate the molecular impact of the loss of Map2k alleles on placenta development.
Project description:The mammalian genome contains two ERK/MAP kinase kinase genes, Map2k1 and Map2k2, encoding dual-specificity kinases responsible for ERK/MAP kinase activation. Loss of Map2k1 function in mouse causes embryonic lethality due to placental defects, while Map2k2 mutant mice survive with a normal lifespan. The Map2k1 mutation interferes with the growth of the labyrinthine region of the placenta and its vascularization. Map2k1+/-Map2k2+/- embryos also die during gestation of underdevelopment of the labyrinth. In Map2k1+/-Map2k2+/- mutants, the vascularization of the labyrinth is reduced and defects in SynT-II formation lead to the accumulation of multinucleated trophoblasts giant cells (MTG). Deletion of both Map2k1 alleles in allantoïs-derived tissues in Map2k1+/ Map2k2+/- placenta (Map2k1flox/-Map2k2+/-Tg+/Sox2Cre) increases the penetrance and the expressivity of the MTG placental phenotype. Microarray analysis with RNA extracted from placentas of E12.5 wt, Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos was performed to evaluate the molecular impact of the loss of Map2k alleles on placenta development. Total RNA was isolated from placentas of E12.5 Map2k1+/+Map2k2+/+(control), from E12.5 Map2k1+/-Map2k2+/- embryos (experimental) and from E12.5 and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos (experimental). Four specimens were analyzed per genotype.
Project description:The placenta serves as the structural interface for nutrient and waste exchange for proper fetal development. Although defects in placental function result in various placental disorders, molecular mechanisms orchestrating placental development and function are poorly understood. Gene targeting studies have shown that Hgf or c-Met KO embryos exhibit growth retardation and markedly smaller size of the placenta, and die by E14.5. Stem/progenitor cells in various tissues express c-Met and they participate in morphogenesis and tissue repair. Thus, we hypothesized that the HGF/c-Met signaling pathway is essential for the emergence, proliferation, and/or differentiation of putative stem/precursor cells of labyrinth trophoblasts at the midgestation stage. To examine the downstream mechanisms of HGF/c-Met signaling pathway that regulate placental labyrinth development, we performed microarray analysis and compared the transcriptional profiles of wild-type and c-Met g-KO placentas. The highly enriched gene ontology categories among the transcripts that were down-regulated in the mutant placentas were related to cell cycle, transcription, and placenta development. Surprisingly, the most highly enriched GO category among the up-regulated genes was immune response. Furthermore, genes classified as “unsaturated fatty acid metabolic process” were also significantly enriched among the up-regulated genes. This expression data suggested that HGF/c-Met signaling pathway positively regulates progression of cell cycle and transcription of placenta specific genes, and negatively regulates inflammatory reaction and fatty acids synthesis in the trophoblasts, thereby coordinating many critical cellular processes in the placenta. Freshly harvested mouse placental trophoblast was enriched for CD9 from wild -type and c-Met KO placenta with 2 independent biological replicates
Project description:Little is known about the genetic regulation of medulloblastoma dissemination, but metastatic medulloblastoma is highly associated with poor outcome. We obtained expression profiles of 23 primary medulloblastomas clinically designated as either metastatic (M+) or non-metastatic (M0) and identified 85 genes whose expression differed significantly between classes. Using a class prediction algorithm based on these genes and a leave-one-out approach, we assigned sample class to these tumors (M+ or M0) with 72% accuracy and to four additional independent tumors with 100% accuracy. We also assigned the metastatic medulloblastoma cell line Daoy to the metastatic class. Notably, platelet-derived growth factor receptor alpha (PDGFRA) and members of the downstream RAS/mitogen-activated protein kinase (MAPK) signal transduction pathway are upregulated in M+ tumors. Immunohistochemical validation on an independent set of tumors shows significant overexpression of PDGFRA in M+ tumors compared to M0 tumors. Using in vitro assays, we show that platelet-derived growth factor alpha (PDGFA) enhances medulloblastoma migration and increases downstream MAP2K1 (MEK1), MAP2K2 (MEK2), MAPK1 (p42 MAPK) and MAPK3 (p44 MAPK) phosphorylation in a dose-dependent manner. Neutralizing antibodies to PDGFRA blocks MAP2K1, MAP2K2 and MAPK1/3 phosphorylation, whereas U0126, a highly specific inhibitor of MAP2K1 and MAP2K2, also blocks MAPK1/3. Both inhibit migration and prevent PDGFA-stimulated migration. These results provide the first insight into the genetic regulation of medulloblastoma metastasis and are the first to suggest a role for PDGFRA and the RAS/MAPK signaling pathway in medulloblastoma metastasis. Inhibitors of PDGFRA and RAS proteins should therefore be considered for investigation as possible novel therapeutic strategies against medulloblastoma. Keywords: other
Project description:Healthy placental development is essential for reproductive success; failure of the feto-maternal interface results in preeclampsia and intrauterine growth retardation. We found that grainyhead-like 2 (GRHL2), a CP2-type transcription factor, is highly expressed in chorionic trophoblast cells, including basal chorionic trophoblast (BCT) cells located at the chorioallantoic interface in murine placentas. Placentas from Grhl2-deficient mouse embryos displayed defects in BCT cell polarity and basement membrane integrity at the chorioallantoic interface, as well as a severe disruption of labyrinth branchingmorphogenesis.Selective Grhl2 inactivation only in epiblastderived cells rescued all placental defects but phenocopied intraembryonic defects observed in global Grhl2 deficiency, implying the importance of Grhl2 activity in trophectoderm-derived cells. ChIPseq identified 5282 GRHL2 binding sites in placental tissue. By integrating these data with placental gene expression profiles, we identified direct and indirect Grhl2 targets and found a marked enrichment of GRHL2 binding adjacent to genes downregulated in Grhl2−/− placentas, which encoded known regulators of placental development and epithelial morphogenesis. These genes included that encoding the serine protease inhibitor Kunitz type 1 (Spint1), which regulates BCT cell integrity and labyrinth formation. In human placenta, we found that human orthologs of murine GRHL2 and its targets displayed co-regulation and were expressed in trophoblast cells in a similar domain as in mouse placenta. Our data indicate that a conserved Grhl2-coordinated gene network controls trophoblast branching morphogenesis, thereby facilitating development of the site of feto-maternal exchange. This might have implications for syndromes related to placental dysfunction. In vivo genome-wide examination of binding sites of the transcription factor GRHL2 by ChIP-seq using wild-type murine E17.5 placenta tissue. Two samples in total: one GRHL2 ChIP sample and one IgG ChIP sample using wild-type placentas tissue as antibody control.
Project description:The placenta serves as the structural interface for nutrient and waste exchange for proper fetal development. Although defects in placental function result in various placental disorders, molecular mechanisms orchestrating placental development and function are poorly understood. Gene targeting studies have shown that Hgf or c-Met KO embryos exhibit growth retardation and markedly smaller size of the placenta, and die by E14.5. Stem/progenitor cells in various tissues express c-Met and they participate in morphogenesis and tissue repair. Thus, we hypothesized that the HGF/c-Met signaling pathway is essential for the emergence, proliferation, and/or differentiation of putative stem/precursor cells of labyrinth trophoblasts at the midgestation stage. To examine the downstream mechanisms of HGF/c-Met signaling pathway that regulate placental labyrinth development, we performed microarray analysis and compared the transcriptional profiles of wild-type and c-Met g-KO placentas. The highly enriched gene ontology categories among the transcripts that were down-regulated in the mutant placentas were related to cell cycle, transcription, and placenta development. Surprisingly, the most highly enriched GO category among the up-regulated genes was immune response. Furthermore, genes classified as “unsaturated fatty acid metabolic process” were also significantly enriched among the up-regulated genes. This expression data suggested that HGF/c-Met signaling pathway positively regulates progression of cell cycle and transcription of placenta specific genes, and negatively regulates inflammatory reaction and fatty acids synthesis in the trophoblasts, thereby coordinating many critical cellular processes in the placenta.
Project description:AIMS/HYPOTHESIS: Pregnancies complicated by diabetes have a higher risk of adverse outcomes for mothers and children, including predisposition to disease later in life, such as metabolic syndrome and hypertension. We hypothesized that adverse outcomes from diabetic pregnancies may be linked to compromised placental function. Our goal in this study was to identify cellular and molecular abnormalities in diabetic placenta. METHODS: Using a mouse model of diabetic pregnancy, placental gene expression was assayed at midgestation and cellular composition was analyzed at various stages. Genome-wide expression profiling was validated by quantitative PCR, and tissue localization studies were performed to identify cellular correlates of altered gene expression in diabetic placenta. RESULTS: We detected significantly altered gene expression in diabetic placenta for genes expressed in the maternal as well as those in the embryonic compartments. We also found altered cellular composition of the decidual compartment. Furthermore, the junctional and labyrinth layers were reduced in diabetic placenta, accompanied by aberrant differentiation of spongiotrophoblast cells. CONCLUSIONS/INTERPRETATION: Diabetes during pregnancy alters transcriptional profiles in the murine placenta, affecting cells of both embryonic and maternal origin, and involving several genes not previously implicated in diabetic pregnancies. The molecular changes and abnormal differentiation of multiple cell types precede impaired growth of junctional zone and labyrinth, and placenta overall. Whether these changes represent direct responses to hyperglycaemia or physiological adaptations, they are likely to play a role in pregnancy complications and outcomes, and have implications for developmental origins of adult disease. The STZ diabetic mouse model was used to investigate gene expression changes in diabetic placentae at E10.5. Placentae were dissected from 5 different FVB dams at embryonic day 10.5 under diabetic conditions and from 5 control dams. Gene expression profiles from five individual placentae from independent pregnancies per group were compared.
Project description:AIMS/HYPOTHESIS: Pregnancies complicated by diabetes have a higher risk of adverse outcomes for mothers and children, including predisposition to disease later in life, such as metabolic syndrome and hypertension. We hypothesized that adverse outcomes from diabetic pregnancies may be linked to compromised placental function. Our goal in this study was to identify cellular and molecular abnormalities in diabetic placenta. METHODS: Using a mouse model of diabetic pregnancy, placental gene expression was assayed at midgestation and cellular composition was analyzed at various stages. Genome-wide expression profiling was validated by quantitative PCR, and tissue localization studies were performed to identify cellular correlates of altered gene expression in diabetic placenta. RESULTS: We detected significantly altered gene expression in diabetic placenta for genes expressed in the maternal as well as those in the embryonic compartments. We also found altered cellular composition of the decidual compartment. Furthermore, the junctional and labyrinth layers were reduced in diabetic placenta, accompanied by aberrant differentiation of spongiotrophoblast cells. CONCLUSIONS/INTERPRETATION: Diabetes during pregnancy alters transcriptional profiles in the murine placenta, affecting cells of both embryonic and maternal origin, and involving several genes not previously implicated in diabetic pregnancies. The molecular changes and abnormal differentiation of multiple cell types precede impaired growth of junctional zone and labyrinth, and placenta overall. Whether these changes represent direct responses to hyperglycaemia or physiological adaptations, they are likely to play a role in pregnancy complications and outcomes, and have implications for developmental origins of adult disease.
Project description:alpha2-adrenoceptors are essential presynaptic regulators of norepinephrine release from sympathetic nerves. Previous studies in mice with targeted deletions in the three alpha2-adrenoceptor genes have indicated that these receptors are essential for embryonic development. In the present study, we searched for the alpha2-adrenoceptor subtype(s) involved in placental development and its molecular mechanism using mice carrying targeted deletions in alpha2-adrenoceptor genes. Congenic alpha2B-adrenoceptor-deficient mice (Adra2b-/-) developed a defect in fetal and maternal vessel formation in the placenta labyrinth at embryonic day E10.5. This defect was accompanied by reduced endothelial cell proliferation and decreased ERK1/2 phosphorylation levels in Adra2b-/- as compared with Adra2b+/+ placenta. Microarray analysis of wild-type and mutant placentae (maternal genotype Adra2b+/-) revealed 179 genes which were significantly up- or downregulated >1.5-fold in alpha2B-deficient placenta. The type 1 receptor for vascular endothelial growth factor (Flt1), which is coexpressed with alpha2B-adrenoceptors in spongiotrophoblast and giant cells of the placenta, was found to be 2.3-fold upregulated in alpha2B-deficient placenta. Neutralization of Flt1 and its soluble splice variant sFlt1 by a specific antibody in vivo prevented the vascular defect in alpha2B-deficient placenta at E10.5. Thus, alpha2B-adrenoceptors are essential to suppress antiangiogenic (s)Flt1 in spongiotrophoblasts to control the coordinated formation of a vascular labyrinth of fetal and maternal blood vessels in the murine placenta during development. Experiment Overall Design: Comparative transcriptome analysis was determined using the GeneChip Mouse Genome 430 2.0 Array (Affymetrix, Santa Clara, CA, USA). Six microarrays from three wild-type and three adra2b deficient mice were performed.
Project description:Healthy placental development is essential for reproductive success; failure of the feto-maternal interface results in preeclampsia and intrauterine growth retardation. We found that grainyhead-like 2 (GRHL2), a CP2-type transcription factor, is highly expressed in chorionic trophoblast cells, including basal chorionic trophoblast (BCT) cells located at the chorioallantoic interface in murine placentas. Placentas from Grhl2-deficient mouse embryos displayed defects in BCT cell polarity and basement membrane integrity at the chorioallantoic interface, as well as a severe disruption of labyrinth branchingmorphogenesis.Selective Grhl2 inactivation only in epiblastderived cells rescued all placental defects but phenocopied intraembryonic defects observed in global Grhl2 deficiency, implying the importance of Grhl2 activity in trophectoderm-derived cells. ChIPseq identified 5282 GRHL2 binding sites in placental tissue. By integrating these data with placental gene expression profiles, we identified direct and indirect Grhl2 targets and found a marked enrichment of GRHL2 binding adjacent to genes downregulated in Grhl2−/− placentas, which encoded known regulators of placental development and epithelial morphogenesis. These genes included that encoding the serine protease inhibitor Kunitz type 1 (Spint1), which regulates BCT cell integrity and labyrinth formation. In human placenta, we found that human orthologs of murine GRHL2 and its targets displayed co-regulation and were expressed in trophoblast cells in a similar domain as in mouse placenta. Our data indicate that a conserved Grhl2-coordinated gene network controls trophoblast branching morphogenesis, thereby facilitating development of the site of feto-maternal exchange. This might have implications for syndromes related to placental dysfunction.