Project description:Placental insufficiency jeopardizes prenatal development, potentially leading to intrauterine growth restriction (IUGR) and stillbirth. Surviving fetuses are at an increased risk for chronic diseases later in life. IUGR is closely linked with altered trophoblast and placental differentiation. However, due to a paucity of mechanistic insights, suitable biomarkers and specific therapies for IUGR are lacking. The transcription factor p45 NF-E2 (nuclear factor erythroid derived 2) has been recently found to regulate trophoblast differentiation in mice. The absence of p45 NF-E2 in trophoblast cells causes IUGR and placental insufficiency in mice, but mechanistic insights are incomplete and the relevance of p45 NF-E2 for human syncytiotrophoblast differentiation remains unknown. Here we show that p45 NF-E2 negatively regulates human syncytiotrophoblast differentiation and is associated with IUGR in humans. Expression of p45 NF-E2 is reduced in human placentae complicated with IUGR compared with healthy controls. Reduced p45 NF-E2 expression is associated with increased syncytiotrophoblast differentiation, enhanced glial cells missing-1 (GCM1) acetylation and GCM1 desumoylation in IUGR placentae. Induction of syncytiotrophoblast differentiation in BeWo and primary villous trophoblast cells with 8-bromo-adenosine 3',5'-cyclic monophosphate (8-Br-cAMP) reduces p45 NF-E2 expression. Of note, p45 NF-E2 knockdown is sufficient to increase syncytiotrophoblast differentiation and GCM1 expression. Loss of p45 NF-E2 using either approach resulted in CBP-mediated GCM1 acetylation and SENP-mediated GCM1 desumoylation, demonstrating that p45 NF-E2 regulates post-translational modifications of GCM1. Functionally, reduced p45 NF-E2 expression is associated with increased cell death and caspase-3 activation in vitro and in placental tissues samples. Overexpression of p45 NF-E2 is sufficient to repress GCM1 expression, acetylation and desumoylation, even in 8-Br-cAMP exposed BeWo cells. These results suggest that p45 NF-E2 negatively regulates differentiation and apoptosis activation of human syncytiotrophoblast by modulating GCM1 acetylation and sumoylation. These studies identify a new pathomechanism related to IUGR in humans and thus provide new impetus for future studies aiming to identify new biomarkers and/or therapies of IUGR.

Project description:Transcriptional profiling of murine erythroleukemia cells induced to differentiate Murine erythroleukemia (MEL) cells are derived from mice infected with the Friend erythroleukemia viral complex, which causes a lethal expansion of erythroid cells. The transformed, immortalized cells (MEL cells) isolated from infected mice are committed to erythroid differentiation, but are blocked roughly at the proerythoblast stage. Treatment with small, oxidized organic compounds like dimethyl sulfoxide or hydroxymethyl-bis-acetamide (HMBA) induce the cells to mature further, to roughly the erythroblast stage or beyond in some lines (Friend et al. 1971). During this induction, the amount of hemoglobin, some heme biosynthetic enzymes and other proteins characteristic of mature erythroid cells increases, largely as a result of changes in transcription (Aviv et al. 1976). A full description of changes in transcription of all mouse genes during this process is not available. To improve this situation, we have conducted transcriptional profiling of the RL5 line of MEL cells, using microarrays containing almost 7000 mouse genes. The RL5 line has a "random locus" containing a positive-negative selectable marker (HyTK) flanked by loxP sites, thus facilitating site-directed integration into the cells (Bouhassira et al. 1997; Feng et al. 1999; Molete et al. 2001). This particular line is not highly inducible, with less than half the cells accumulating large amounts of hemoglobin. However, they are advantageous for integration of expression constructs, which is our particular interest. MEL_RL5 cells were treated with 4 millimolar HMBA for 6 days to induce maturation, and RNA was isolated each day. Complementary DNA was synthesized and labeled with either Cy5 (red fluorescence) for the induced samples or Cy3 (green fluorescence) the untreated cells grown in parallel. For most time points, at least two independent experiments were run, some with dyes switched (SD). The microarrays were spotted at the PSU Microarray Facility. Hybridization was carried out in our laboratory, and hybridized chips were scanned on a GenePix scanner and quantified using GenePix software. The signals from each channel (red and green) were normalized so that the total red intensity equals the total green intensity. Data were filtered to remove "bad" spots, which are those in which the noise exceeded the signal. We calculated the median of the pixel intensities for each spot and standard deviation around the median, and with these values we computed a "modified Z-score" for each channel on each spot. A lenient threshold for the "modified Z-score" was applied to remove "bad" spots. After filtering, we performed global mean normalization for each chip, followed by lowess normalization for each chip to remove intensity-dependent effects. Keywords: time-course

Project description:Transcriptional profiling of murine erythroleukemia cells induced to differentiate Murine erythroleukemia (MEL) cells are derived from mice infected with the Friend erythroleukemia viral complex, which causes a lethal expansion of erythroid cells. The transformed, immortalized cells (MEL cells) isolated from infected mice are committed to erythroid differentiation, but are blocked roughly at the proerythoblast stage. Treatment with small, oxidized organic compounds like dimethyl sulfoxide or hydroxymethyl-bis-acetamide (HMBA) induce the cells to mature further, to roughly the erythroblast stage or beyond in some lines (Friend et al. 1971). During this induction, the amount of hemoglobin, some heme biosynthetic enzymes and other proteins characteristic of mature erythroid cells increases, largely as a result of changes in transcription (Aviv et al. 1976). A full description of changes in transcription of all mouse genes during this process is not available. To improve this situation, we have conducted transcriptional profiling of the RL5 line of MEL cells, using microarrays containing almost 7000 mouse genes. The RL5 line has a "random locus" containing a positive-negative selectable marker (HyTK) flanked by loxP sites, thus facilitating site-directed integration into the cells (Bouhassira et al. 1997; Feng et al. 1999; Molete et al. 2001). This particular line is not highly inducible, with less than half the cells accumulating large amounts of hemoglobin. However, they are advantageous for integration of expression constructs, which is our particular interest. MEL_RL5 cells were treated with 4 millimolar HMBA for 6 days to induce maturation, and RNA was isolated each day. Complementary DNA was synthesized and labeled with either Cy5 (red fluorescence) for the induced samples or Cy3 (green fluorescence) the untreated cells grown in parallel. For most time points, at least two independent experiments were run, some with dyes switched (SD). The microarrays were spotted at the PSU Microarray Facility. Hybridization was carried out in our laboratory, and hybridized chips were scanned on a GenePix scanner and quantified using GenePix software. The signals from each channel (red and green) were normalized so that the total red intensity equals the total green intensity. Data were filtered to remove "bad" spots, which are those in which the noise exceeded the signal. We calculated the median of the pixel intensities for each spot and standard deviation around the median, and with these values we computed a "modified Z-score" for each channel on each spot. A lenient threshold for the "modified Z-score" was applied to remove "bad" spots. After filtering, we performed global mean normalization for each chip, followed by lowess normalization for each chip to remove intensity-dependent effects.

Dataset Information

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells.

Publications

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells.

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