During oocyte growth, chromatin structure is altered globally and gene expression is silenced. To investigate the involvement of epigenetic modifications in the regulation of these phenomena, changes in global DNA methylation and in various histone modifications, i.e. acetylation of H3K9, H3K18, H4K5, and H4K12, and methylation of H3K4 and H3K9, were examined during the growth of mouse oocytes. Immunocytochemical analysis revealed that the signal intensities of all these modifications increased during growth and that fully grown, germinal vesicle (GV)-stage oocytes showed the most modifications. Since acetylation of most of the lysine residues on histones and methylation of H3K4 are associated with active gene expression, the increased levels of these modifications do not seem to be associated with gene silencing in GV-stage oocytes. Given that there are two types of GV-stage oocytes with different chromatin configurations and transcriptional activities, the epigenetic modification statuses of these two types were compared. The levels of all the epigenetic modifications examined were higher in the SN(surrounded nucleolus)-type oocytes, in which highly condensed chromatin is concentrated in the area around the nucleolus and gene expression is silenced than in the NSN(not surrounded nucleolus)-type oocytes, in which less-condensed chromatin does not surround the nucleolus and gene expression is active. In addition, the expression levels of various enzymes that catalyze histone modifications were shown by RT-PCR to increase with oocyte growth. Taken together, the results show that all of the epigenetic modifications increased in a concerted manner during oocyte growth, and suggest that these increases are not associated with gene expression. Reproduction (2007) 133 85-94

During oogenesis, mRNA is actively transcribed and accumulated in growing oocytes, but this transcription stops before the oocytes grow to their full size. The accumulated maternal mRNA is used for protein synthesis in the oocytes during meiotic maturation and even in the embryos to sustain development after fertilization. Therefore, the degradation of accumulated maternal mRNA starts during meiotic maturation, but its rate is slow. Nevertheless, some mRNA species should rapidly degrade after fertilization if they encode proteins that play a role in specific events during meiosis and are detrimental for development after fertilization. In this study, to identify the selective degradation of maternal transcripts after fertilization, we sought mRNAs that are degraded in the early hours after fertilization by constructing an oocyte cDNA library after subtracting the cDNA of embryos at the mid one-cell stage. H1oo, c-mos, tPA (tissue type plasminogen activator gene), and Gdf9 were identified as genes whose transcripts undergo rapid degradation after fertilization. RT-PCR analysis showed that none of these transcripts was expressed during pre-implantation development once they were eliminated, suggesting that the mRNA species that are required for oogenesis, but not for early pre-implantation development, are degraded rapidly after fertilization. Microinjection of chimeric mRNAs in which the coding and 3'-untranslated regions (3'UTR) were exchanged between c-mos and hypoxanthine phosphoribosyltransferase mRNAs revealed that the 3'UTR plays a role in the rapid degradation that occurs after fertilization. Cytoplasmic polyadenylation elements (CPEs) was found near a poly(A) signal in the 3'UTR of all the mRNA species identified as rapidly degrading mRNA. The mechanism for the selective degradation is discussed, in relation to its biological significance.

A unique pentaketide dimer structure of a novel fungal metabolite with antiangiogenic activity, designated as epoxyquinol A (1), was determined on the basis of NMR spectral data as well as the X-ray crystallographic analysis. 1 inhibits the endothelial migration induced by vascular endothelial growth factor (ED100 = 3 mug/mL).

To identify genetic events that characterize cancer progression, we conducted a comprehensive genetic evaluation of 161 primary breast tumors. Similar to the ''mountain-and-hill'' view of mutations, gene amplification also shows high-and low-frequency alterations in breast cancers. The frequently amplified genes include the well-known oncogenes ERBB2, FGFR1, MYC, CCND1, and PIK3CA, whereas other known oncogenes that are amplified, although less frequently, include CCND2, EGFR, FGFR2, and NOTCH3. More importantly, by honing in on minimally amplified regions containing three or fewer genes, we identified six new amplified genes: POLD3, IRAK4, IRX2, TBL1XR1, ASPH, and BRD4. We found that both the IRX2 and TBL1XR1 proteins showed higher expression in the malignant cell lines MCF10CA1h and MCF10CA1a than in their precursor, MCF10A, a normal immortalized mammary epithelial cell line. To study oncogenic roles of TBL1XR1, we performed knockdown experiments using a short hairpin RNA approach and found that depletion of TBL1XR1 in MCF10CA1h cells resulted in reduction of cell migration and invasion as well as suppression of tumorigenesis in mouse xenografts. Intriguingly, our mutation analysis showed the presence of activation mutations in the PIK3CA gene in a subset of tumors that also had DNA copy number increases in the PIK3CA locus, suggesting an additive effect of coexisting activating amino acid substitution and dosage increase from amplification. Our gene amplification and somatic mutation analysis of breast primary tumors provides a coherent picture of genetic events, both corroborating and novel, offering insight into the genetic underpinnings of breast cancer progression. [Cancer Res 2009;69(18):7357-65]

These results indicate the pathophysiologic significance of the death receptor apoptotic pathway, including FADD, in septic ALI and the potential usefulness of FADD siRNA for gene therapy of the septic syndrome.

Gene silencing of caspase-8 and caspase-3 with siRNAs provided profound protection against polymicrobial endotoxic shock. The prevention of vascular endothelial cell apoptosis appears to be, at least in part, responsible for their beneficial effects in endotoxic shock.

The use of glucocorticoids for treatment of sepsis has waxed and waned during the past several decades, and recent randomized controlled trials have evoked a reassessment of this therapy. Most glucocorticoid actions are mediated by its specific intracellular receptors (GRs). Thus we initially evaluated whether sepsis and high-dose corticosteroid therapy can regulate guinea pig pulmonary expression of GRs: active receptor, GRalpha, and dominant negative receptor, GRbeta. Sepsis induction by LPS injection (300 mug/kg ip) decreased mRNA and protein levels of GRalpha and increased protein expression of GRbeta in lungs. High-dose methylprednisolone (40 mg/kg ip), administered simultaneously with LPS, markedly potentiated the decrease in GRalpha expression but slightly affected the increase in GRbeta expression. Consequently, this led to a significant reduction in GRalpha nuclear translocation. Nevertheless, methylprednisolone treatment strongly eliminated LPS induction of NF-kappaB activity, as determined by NF-kappaB nuclear translocation and by gel mobility shift assays. Furthermore, the LPS-induced increase in inflammatory cells in bronchoalveolar lavage fluid was blunted by administration of the corticosteroid. On the other hand, immunofluorescent staining for cleaved caspase-3 showed a marked increase in this proapoptotic marker in lung sections, and terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling (TUNEL) represented an enhanced appearance of cell apoptosis in lungs and spleen when methylprednisolone was given together with LPS. Cell apoptosis is now considered to play a role in the pathogenesis of septic syndrome. We thus suggest that the action of glucocorticoids at high doses to accelerate sepsis-induced cell apoptosis may overwhelm their therapeutic advantages in septic shock.

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