Project description:We studied the transcriptional profile in response to acute PtdIns-4,5P2 depletion induced by heterologous expression of a plasma membrane-directed version of mammalian PI3K catalytic subunit (p110α-CAAX).
Project description:We studied the transcriptional profile in response to acute PtdIns-4,5P2 depletion induced by heterologous expression of a plasma membrane-directed version of mammalian PI3K catalytic subunit (p110M-NM-1-CAAX). Three biological samples were analyzed for samples expressing for 4 hours p110M-NM-1-CAAX (PI3K) versus the kinase dead mutant p110M-NM-1-CAAX K802R (KD), and one microarray experiment was carried out for each sample.
Project description:MicroRNAs regulated by lipopolysaccharide (LPS) target genes that contribute to the inflammatory phenotype. Here we showed that the protein kinase Akt1, which is activated by LPS, positively regulated miRNAs let-7e, miR-181c but negatively regulated miR-155 and miR-125b. In silico analyses and transfection studies revealed that let-7e repressed Toll-like receptor 4 (TLR4) whereas miR-155 repressed SOCS1, two proteins critical for LPS-driven TLR signalling, which regulate endotoxin sensitivity and tolerance. As a result, Akt1-/- macrophages exhibited increased responsiveness to LPS in culture and Akt1-/- mice did not develop endotoxin tolerance in vivo. Overexpression of let-7e and suppression of miR-155 in Akt1-/- macrophages restored sensitivity and tolerance to LPS in culture and in animals. These results indicate that Akt1 regulates the response of macrophages to LPS by controlling miRNA expression. The data deposited here contain the entire analysis of miRNA profile of Akt1+/+ and Akt1-/- thioglycollate elicited peritoneal macrophages following stimulation with LPS for 3 hours in culture.
Project description:In the mammalian heart AKT1 and AKT2 are the isoforms of the protein kinase AKT (protein kinase B) which are predominantly expressed. AKT isoforms exert common and specific functions in the field of metabolism, cellular growth, apoptosis and cell migration. To identify specific and common functions of AKT1 and AKT2 isoforms, we generated tamoxifen-inducible, cardiomyocyte-specific AKT1, AKT2, and AKT1+AKT2 double knockout mice (iCMAKT – KO mice). Inactivation of AKT isoforms was achieved by application of 4-OH-tamoxifen, which activates an OH-Tx inducible cre-recombinase expressed under the control of the αMHC-promoter (αMHC-mercremer). Transgenic mice expressing only the αMHCmercremer construct were also treated with OH-Tx and served as controls. To identify alterations in cardiac gene expression due to AKT deletion we analyzed gene expression profiles of control hearts, iCMAKT1, iCMAKT2 and iCMAKT1+2 hearts.
Project description:MicroRNAs regulated by lipopolysaccharide (LPS) target genes that contribute to the inflammatory phenotype. Here we showed that the protein kinase Akt1, which is activated by LPS, positively regulated miRNAs let-7e, miR-181c but negatively regulated miR-155 and miR-125b. In silico analyses and transfection studies revealed that let-7e repressed Toll-like receptor 4 (TLR4) whereas miR-155 repressed SOCS1, two proteins critical for LPS-driven TLR signalling, which regulate endotoxin sensitivity and tolerance. As a result, Akt1-/- macrophages exhibited increased responsiveness to LPS in culture and Akt1-/- mice did not develop endotoxin tolerance in vivo. Overexpression of let-7e and suppression of miR-155 in Akt1-/- macrophages restored sensitivity and tolerance to LPS in culture and in animals. These results indicate that Akt1 regulates the response of macrophages to LPS by controlling miRNA expression. The data deposited here contain the entire analysis of miRNA profile of Akt1+/+ and Akt1-/- thioglycollate elicited peritoneal macrophages following stimulation with LPS for 3 hours in culture. Thioglycollate elicited macrophages were cultured in complete DMEM medium, stimulated with LPS for 3 hours and RNA was extracted. Samples were analyzed using Taq-man PCR miRNA arrays (Dana Farber microarray Facility).
Project description:AKT1 is a serine/threonine kinase implicated in fetal, placental, and postnatal growth. In this study, we investigated roles for AKT1 in placental development using a genome-edited/loss-of-function rat model. Both heterozygous and homozygous Akt1 mutant rats were viable and fertile. Disruption of AKT1 resulted in placental, fetal, and postnatal growth restriction. Akt1 null placentas showed deficits in both junctional zone and labyrinth zone size and their ability to adapt to a physiological stressor. Robust differences in the transcriptome of wild type versus Akt1 null junctional zones were identified. Among the differentially expressed junctional zone transcripts was forkhead box O4 (Foxo4), which encodes a transcription factor and known AKT substrate. FOXO4 expression was prominent in the junctional zone and invasive trophoblast cells of the rat placentation site and enhanced following rat TS cell differentiation. Foxo4 gene disruption using genome-editing resulted in placentomegaly, including an enlarged junctional zone. AKT1 and FOXO4 regulate the expression of many of the same transcripts expressed by trophoblast cells; however, in opposite directions. In summary, we have identified AKT1 and FOXO4 as part of a regulatory network controlling hemochorial placenta development.
Project description:AKT1 is a serine/threonine kinase implicated in fetal, placental, and postnatal growth. In this study, we investigated roles for AKT1 in placental development using a genome-edited/loss-of-function rat model. Both heterozygous and homozygous Akt1 mutant rats were viable and fertile. Disruption of AKT1 resulted in placental, fetal, and postnatal growth restriction. Akt1 null placentas showed deficits in both junctional zone and labyrinth zone size and their ability to adapt to a physiological stressor. Robust differences in the transcriptome of wild type versus Akt1 null junctional zones were identified. Among the differentially expressed junctional zone transcripts was forkhead box O4 (Foxo4), which encodes a transcription factor and known AKT substrate. FOXO4 expression was prominent in the junctional zone and invasive trophoblast cells of the rat placentation site and enhanced following rat TS cell differentiation. Foxo4 gene disruption using genome-editing resulted in placentomegaly, including an enlarged junctional zone. AKT1 and FOXO4 regulate the expression of many of the same transcripts expressed by trophoblast cells; however, in opposite directions. In summary, we have identified AKT1 and FOXO4 as part of a regulatory network controlling hemochorial placenta development.
Project description:In the mammalian heart AKT1 and AKT2 are the isoforms of the protein kinase AKT (protein kinase B) which are predominantly expressed. AKT isoforms exert common and specific functions in the field of metabolism, cellular growth, apoptosis and cell migration. To identify specific and common functions of AKT1 and AKT2 isoforms, we generated tamoxifen-inducible, cardiomyocyte-specific AKT1+AKT2 double knockout mice (iCMAKT – KO mice). Inactivation of AKT isoforms was achieved by application of 4-OH-tamoxifen, which activates an OH-Tx inducible cre-recombinase expressed under the control of the αMHC-promoter (αMHC-mercremer). Transgenic mice expressing only the αMHCmercremer construct were also treated with OH-Tx and served as controls. To identify alterations in cardiac gene expression due to AKT deletion we analyzed gene expression profiles of control hearts and iCMAKT1+2 hearts.
Project description:In contrast to the well-established role of oxidative muscle fibers in regulating fatty acid oxidation and whole body metabolism, little is known that about the function of fast/glycolytic muscle fibers in these processes. Here, we generated a skeletal muscle-specific, conditional transgenic mouse expressing a constitutively-active form of Akt1. Transgene activation led to muscle hypertrophy due to the growth of type IIb muscle fibers, which was accompanied by an increase in strength. These mice were then used to assess the consequence of building fast/glycolytic muscle fibers on adiposity and metabolism. Akt1 transgene induction in obese mice resulted in reductions in body weight and fat mass, a resolution of hepatic steatosis and improved metabolic parameters. These effects were achieved independent of changes in physical activity and levels of food consumption. Akt1-mediated skeletal muscle growth opposed the effects of high fat/sucrose diet on transcript expression patterns in the liver, and increased hepatic fatty acid oxidation and ketone body production. Our findings indicate that an increase in fast/glycolytic muscle mass can result in the regression of obesity and obesity-related metabolic disorders in part through its ability to alter fatty acid metabolism in remote tissues. Experiment Overall Design: 11 samples are included in this series. 3 wild-type mice fed on a normal diet, 4 wild-type mice fed on a HF diet, and 4 Akt1 double transgenic mice fed on a HF diet. All samples are on the mixed background.