Expression Analysis of the NLRP Gene Family Suggests a Role in Human Preimplantation Development

Background: The NLRP (Nucleotide-binding oligomerization domain, Leucine rich Repeat and Pyrin domain containing) family, also referred to as NALP family, is well known for its roles in apoptosis and inflammation. Several NLRPs have been indicated as being involved in reproduction as well. Methodology: We studied, using the unique human gametes and embryo materials, the expression of the NLRP family in human gametes and preimplantation embryos at different developmental stages, and compared the expression levels between normal and abnormal embryos using real-time PCR. Principal Findings: Among 14 members of the NLRP family, twelve were detected in human oocytes and preimplantation embryos, whereas seven were detected in spermatozoa. Eight NLRPs (NLRP4, 5, 8, 9, 11, 12, 13, and 14) showed a similar expression pattern: their expression levels were high in oocytes and then decreased progressively in embryos, resulting in a very low level in day 5 embryos. However, NLRP2 and NLRP7 showed a different expression pattern: their expression decreased from oocytes to the lowest level by day 3, but increased again by day 5. The expression levels of NLRP5, 9, and 12 were lower in day 1 abnormal embryos but higher in day3 and day5 arrested embryos, when compared with normal embryos at the same stages. NLRP7 was down-regulated in day 1 and day 5 abnormal embryos but over-expressed in day3 arrested embryos

Proteomics-Based Systems Biology Modeling of Bovine Germinal Vesicle Stage Oocyte and Cumulus Cell Interaction

BACKGROUND: Oocytes are the female gametes which establish the program of life after fertilization. Interactions between oocyte and the surrounding cumulus cells at germinal vesicle (GV) stage are considered essential for proper maturation or 'programming' of oocytes, which is crucial for normal fertilization and embryonic development. However, despite its importance, little is known about the molecular events and pathways involved in this bidirectional communication. METHODOLOGY/PRINCIPAL FINDINGS: We used differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) on bovine GV oocyte and cumulus cells and identified 811 and 1247 proteins in GV oocyte and cumulus cells, respectively; 371 proteins were significantly differentially expressed between each cell type. Systems biology modeling, which included Gene Ontology (GO) and canonical genetic pathway analysis, showed that cumulus cells have higher expression of proteins involved in cell communication, generation of precursor metabolites and energy, as well as transport than GV oocytes. Our data also suggests a hypothesis that oocytes may depend on the presence of cumulus cells to generate specific cellular signals to coordinate their growth and maturation. CONCLUSIONS/SIGNIFICANCE: Systems biology modeling of bovine oocytes and cumulus cells in the context of GO and protein interaction networks identified the signaling pathways associated with the proteins involved in cell-to-cell signaling biological process that may have implications in oocyte competence and maturation. This first comprehensive systems biology modeling of bovine oocytes and cumulus cell proteomes not only provides a foundation for signaling and cell physiology at the GV stage of oocyte development, but are also valuable for comparative studies of other stages of oocyte development at the molecular level

Differential Gene Expression Patterns of EBV Infected EBNA-3A Positive and Negative Human B Lymphocytes

The genome of Epstein-Barr virus (EBV) encodes 86 proteins, but only a limited set is expressed in EBV–growth transformed B cells, termed lymphoblastoid cell lines (LCLs). These cells proliferate via the concerted action of EBV nuclear antigens (EBNAs) and latent membrane proteins (LMPs), some of which are rate limiting to establish a stable homeostasis of growth promoting and anti-apoptotic activities. We show here that EBV mutants, which lack the EBNA-3A gene, are impaired but can still initiate cell cycle entry and proliferation of primary human B cells in contrast to an EBNA-2 deficient mutant virus. Surprisingly, and in contrast to previous reports, these viral mutants are attenuated in growth transformation assays but give rise to permanently growing EBNA-3A negative B cell lines which exhibit reduced proliferation rates and elevated levels of apoptosis. Expression profiles of EBNA-3A deficient LCLs are characterized by 129 down-regulated and 167 up-regulated genes, which are significantly enriched for genes involved in apoptotic processes or cell cycle progression like the tumor suppressor gene p16/INK4A, or might contribute to essential steps of the viral life cycle in the infected host. In addition, EBNA-3A cellular target genes remarkably overlap with previously identified targets of EBNA-2. This study comprises the first genome wide expression profiles of EBNA-3A target genes generated within the complex network of viral proteins of the growth transformed B cell and permits a more detailed understanding of EBNA-3A's function and contribution to viral pathogenesis

Effect of cyclin-dependent kinase inhibitors on oocyte cell cycle progression and on cumulus oocyte complex functionality

International audienc

Expression of maternal transcripts during bovine oocyte In vitro maturation is affected by donor age

The primary objective of this study was to compare expression of maternal transcripts in bovine oocyte populations with differential developmental competence: oocytes from prepubertal and pubertal animals; and oocytes from small (3–4 mm) and large (6–10 mm) follicles from pubertal animals. All transcripts were examined in oocytes prior to and after in vitro maturation (IVM). Genes were selected based on their known maternal effect in mouse (ZAR1, STELLA, HSF1, MATER⁄ NLRP5 and its paralogue NLRP9), or their identification as markers of oocyte maturation, either involved in redox metabolism (PRDX1, PRDX2) or meiotic progression (AURKA). Total or polyadenylated forms of the transcripts were followed by reverse transcription coupled to real-time PCR. Six polyadenylated transcripts were found significantly reduced after maturation irrespective of donor age or follicle diameter (p < 0.05). Within these six polyadenylated transcripts, ZAR1, NLRP9, HSF1, PRDX1 and PRDX2 were significantly reduced in oocytes from prepubertal animals compared to adult animals (p < 0.05). A younger age was also associated with lower abundance (total form) of PRDX2⁄ PRDX1 irrespective of maturation. Total HSF1, PRDX1 and polyadenylated NLRP9 showed a tendency (p values from 0.053 to 0.08) for a higher detection in oocytes from small follicles, thus encouraging further investigation of the follicle diameter model. However, at the present time, follicle size did not significantly affect expression of transcripts examined. In conclusion, this study demonstrates differences in the maternal store of RNA and its regulation during IVM which is dependent on donor age

Expression of maternal transcripts during bovine oocyte in vitro maturation is affected by donor age

 absen

Approches non invasives de l'embryon : protéomique, métabolomique, dialogue ovocyte-cumulus

National audienc