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Series GSE26381 Query DataSets for GSE26381
Status Public on Feb 21, 2011
Title The Kinase SGK1 in the Endoderm and Mesoderm Promotes Ectodermal Survival by Downregulating Components of the Death-Inducing Signaling Complex
Organism Xenopus laevis
Experiment type Expression profiling by array
Summary A balance between cell survival and apoptosis is essential for animal development. Although proper development involves multiple interactions between germ layers, little is known about the intercellular and intertissue signaling pathways that promote cell survival in neighboring or distant germ layers . We show that serum- and glucocorticoid-inducible kinase 1 (SGK1) promoted ectodermal cell survival during early Xenopus embryogenesis through a non-cell-autonomous mechanism. Dorsal depletion of SGK1 in Xenopus embryos resulted in shortened axes and reduced head structures with defective eyes, and ventral depletion led to defective tail morphologies. Although the gene encoding SGK1 was mainly expressed in the endoderm and dorsal mesoderm, knockdown of SGK1 caused excessive apoptosis in the ectoderm. SGK1-depleted ectodermal explants showed little or no apoptosis, suggesting non-cell-autonomous effects of SGK1 on ectodermal cells. Microarray analysis revealed that SGK1 knockdown increased the expression of genes encoding FADD and caspase-10, components of the death-inducing signaling complex (DISC). Inhibition of DISC function suppressed excessive apoptosis in SGK1-knockdown embryos. SGK1 acted through the transcription factor nuclear factor kappaB to stimulate production of bone morphogenetic protein 7 (BMP7), and overexpression of BMP7 in SGK1-knockdown embryos reduced the abundance of DISC components. We show that phosphoinositide 3-kinase (PI3K) functioned upstream of SGK1, thus revealing an endodermal and mesodermal pathway from PI3K to SGK1 to NF-kappaB that produces BMP7, which provides a survival signal to the ectoderm by decreasing DISC function.
Overall design To identify genes whose expression levels are regulated by SGK1 in Xenopus development, we performed genome-wide analysis by using Affymetrix GeneChip oligonucleotide microarrays.
We performed two independent experiments. For each microarray experiment, we radially injected control-morpholino or xSGK1-morpholinos into 4-cell embryos, cultured the embryos until stage 12, extracted total RNAs using Trizol (Invitrogen) and purified them on RNeasy columns (Qiagen). Synthesis of cDNA, in vitro transcription and biotin labeling of cRNA, and hybridization to the Xenopus laevis genome array (Affymetrix) were performed according to the Affymetrix protocol (Two-Cycle Target Labeling Assays). Hybridized arrays were scanned using an Affymetrix GeneChip Scanner. Scanned chip images were analyzed with GeneChip Operating Software (GCOS) v. 1.4.
Contributor(s) Endo T, Kusakabe M, Sunadome K, Yamamoto T, Nishida E
Citation(s) 21245468
Submission date Dec 30, 2010
Last update date Mar 23, 2012
Contact name Eisuke Nishida
Phone +81-75-753-4230
Organization name Graduate School of Biostudies, Kyoto University
Department Department of Cell and Developmental Biology
Street address Kitashirakawa, Sakyo-ku
City Kyoto
ZIP/Postal code 606-8502
Country Japan
Platforms (1)
GPL1318 [Xenopus_laevis] Affymetrix Xenopus laevis Genome Array
Samples (4)
GSM647636 Xenopus_control-morpholino_rep1
GSM647637 Xenopus_xSGK1-morpholinos_rep1
GSM647638 Xenopus_control-morpholino_rep2
BioProject PRJNA136611

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Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE26381_RAW.tar 9.0 Mb (http)(custom) TAR (of CEL)
Processed data included within Sample table

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