A gene expression signature shared by human mature oocytes and embryonic stem cells

<p>Abstract</p> <p>Background</p> <p>The first week of human pre-embryo development is characterized by the induction of totipotency and then pluripotency. The understanding of this delicate process will have far reaching implication for in vitro fertilization and regenerative medicine. Human mature MII oocytes and embryonic stem (ES) cells are both able to achieve the feat of cell reprogramming towards pluripotency, either by somatic cell nuclear transfer or by cell fusion, respectively. Comparison of the transcriptome of these two cell types may highlight genes that are involved in pluripotency initiation.</p> <p>Results</p> <p>Based on a microarray compendium of 205 samples, we compared the gene expression profile of mature MII oocytes and human ES cells (hESC) to that of somatic tissues. We identified a common oocyte/hESC gene expression profile, which included a strong cell cycle signature, genes associated with pluripotency such as <it>LIN28 </it>and <it>TDGF1</it>, a large chromatin remodelling network (<it>TOP2A, DNMT3B, JARID2, SMARCA5, CBX1, CBX5</it>), 18 different zinc finger transcription factors, including <it>ZNF84</it>, and several still poorly annotated genes such as <it>KLHL7</it>, <it>MRS2</it>, or the Selenophosphate synthetase 1 (<it>SEPHS1</it>). Interestingly, a large set of genes was also found to code for proteins involved in the ubiquitination and proteasome pathway. Upon hESC differentiation into embryoid bodies, the transcription of this pathway declined. In vitro, we observed a selective sensitivity of hESC to the inhibition of the activity of the proteasome.</p> <p>Conclusion</p> <p>These results shed light on the gene networks that are concurrently overexpressed by the two human cell types with somatic cell reprogramming properties.</p

E4F1 deficiency results in oxidative stress–mediated cell death of leukemic cells

Deletion of E4F1 inflicts mitochondrial damage and oxidative stress on murine and human myeloid leukemia cells but not healthy macrophages

Expression Map of the Human Exome in CD34+ Cells and Blood Cells: Increased Alternative Splicing in Cell Motility and Immune Response Genes

International audienceBACKGROUND: Hematopoietic cells are endowed with very specific biological functions, including cell motility and immune response. These specific functions are dramatically altered during hematopoietic cell differentiation, whereby undifferentiated hematopoietic stem and progenitor cells (HSPC) residing in bone marrow differentiate into platelets, red blood cells and immune cells that exit into the blood stream and eventually move into lymphoid organs or inflamed tissues. The contribution of alternative splicing (AS) to these functions has long been minimized due to incomplete knowledge on AS events in hematopoietic cells. PRINCIPAL FINDINGS: Using Human Exon ST 1.0 microarrays, the entire exome expression profile of immature CD34+ HSPC and mature whole blood cells was mapped, compared to a collection of solid tissues and made freely available as an online exome expression atlas (Amazonia Exon! : http://amazonia.transcriptome.eu/exon.php). At a whole transcript level, HSPC strongly expressed EREG and the pluripotency marker DPPA4. Using a differential splicing index scheme (dsi), a list of 849 transcripts differentially expressed between hematopoietic cells and solid tissues was computed, that included NEDD9 and CD74. Some of these genes also underwent alternative splicing events during hematopoietic differentiation, such as INPP4B, PTPLA or COMMD6, with varied contribution of CD3+ T cells, CD19+ B cells, CD14+ or CD15+ myelomonocytic populations. Strikingly, these genes were significantly enriched for genes involved in cell motility, cell adhesion, response to wounding and immune processes. CONCLUSION: The relevance and the precision provided by this exon expression map highlights the contribution of alternative splicing to key feature of blood cells differentiation and function

Mutation V617F de JAK2 et thromboses abdominales idiopathiques (étude rétrospective sur 10 ans)

MONTPELLIER-BU Médecine UPM (341722108) / SudocMONTPELLIER-BU Médecine (341722104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Utilisation des cellules médullaires pour améliorer la fonction cardiaque : étude dans un modèle de cardiopathie murine

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Lysosomes and Storage diseases

info:eu-repo/semantics/publishe

[Biology and potential of human embryonic stem cells]

International audienceHuman embryonic stem cells (hESC) are obtained from the inner cell mass from the early embryo at blastocyste stage. Derived in cell lines for the first time in 1998, they can be maintained in culture in an undifferentiated state indefinitely under certain conditions. Two essential properties characterize hESC: pluripotency and self-renewal. Pluripotency is convey by the expression of specific transcription factors such as OCT4 and NANOG, and is under the control of growth factors such as IGF2 and FGFb. Markers used to characterize these cells include surface antigens, notably SSEA-3 and SSEA-4, and nuclear markers such as OCT4. HESC can differentiate into different cell types in vitro. They represent a unique and essential model for early human development research and for regenerative medicine. By their self-renewal capacity and their potential to differentiate into several cell types, hESC are an unlimited source of cells enabling to replace or restore lost or damaged cells in numerous diseases. Even if it is not conceivable today to use them in clinical practice for ethic and scientific reasons, it seems essential to explore the numerous potentialities of these cells. This knowledge might be relevant to handle adult stem cells in vitro and will be mandatory for a therapeutic use of hESC in the future

Clinical, biochemical, and ultrastructural studies in a case of chondrodystrophy presenting the I-cell phenotype in tissue culture

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Gene expression profile of human endometrial receptivity: comparison between natural and stimulated cycles for the same patients.

International audienceBACKGROUND: The adjunction of exogenous hormones for controlled ovarian stimulation (COS) may alter endometrial receptiveness. In order to identify the genes misregulated under COS, we compared the endometrium gene expression profiles, from the same patients, in a natural cycle and in a subsequent COS cycle. METHODS: For the same normal-responder patients (n = 21), endometrial biopsies (n = 84) were collected during the pre-receptive (LH + 2) and receptive stages (LH + 7) of a natural cycle and, subsequently, on oocyte retrieval day (hCG + 2) and on transfer day (hCG + 5) of a stimulated cycle. Samples were analyzed using DNA microarrays. Gene expression profiles and biological pathways involved in endometrial receptivity were analyzed. RESULTS: Although endometrium transition profiles from pre-receptive to receptive phases are similar between patients, COS regimens alter endometrial receptivity in comparison with natural cycle. Under COS conditions, two endometrial profiles were identified and were associated either with a moderately altered receptivity profile for the majority of the patients or a strongly altered profile for a sub-category of patients. The receptive endometrium transcription profile under COS was defective for biological functions such as TGFbeta signaling, leukocyte transendothelial migration and the cell cycle. CONCLUSIONS: Gonadotrophin treatments in COS cycles led to disruptions of the transcriptional activation of genes involved in normal endometrial receptivity. We propose that when the receptiveness of the endometrium is seriously compromised by the COS protocol, fresh embryo replacement should be cancelled, the embryo frozen and thawed embryo replacement should be performed under natural cycles