Genes upregulated in the amnion at labour are bivalently marked by activating and repressive histone modifications.

Inflammatory genes are expressed increasingly in the foetal membranes at late gestation triggering birth. Here we have examined whether epigenetic histone modifications contribute to the upregulation of proinflammatory genes in the amnion in late pregnancy and at labour. Amnion samples were collected from early pregnancy, at term in the absence of labour and after spontaneous birth. The expression of the labour-associated proinflammatory genes PTGS2, BMP2 and NAMPT was determined by reverse transcription-coupled quantitative real-time PCR (qRT-PCR). Chromatin immunoprecipitation (ChIP) and sequential double ChIP were performed to determine the levels and co-occurrence of activating histone-3, lysine-4 trimethylation (H3K4me3) and repressive histone-3, lysine-27 trimethylation (H3K27me3) at the gene promoters. H3K4 methyltransferase, H3K27me3 demethylase and H3K27 methyltransferase expression was determined by qRT-PCR and immunofluorescence confocal microscopy. PTGS2, BMP2 and NAMPT expression was upregulated robustly between early pregnancy and term (P < 0.05). The promoters were marked bivalently by both the H3K4me3 and H3K27me3 modifications. Bivalence was reduced at term by the decrease of the H3K27me3-modified fraction of promoter copies marked by H3K4me3 indicating epigenetic activation. Messenger RNAs encoding the H3K4-specific methyl transferases MLL1,-2,-3,-4, SETD1A,-B and the H3K27me3-specific demethylases KDM6A,-B were expressed increasingly while the H3K27 methyl transferase EZH2 was expressed decreasingly at term. Histone modifying enzyme proteins were detected in amnion epithelial and mesenchymal cells. These results with prototypical proinflammatory genes suggest that nucleosomes at labour-promoting genes are marked bivalently in the amnion, which is shifted towards monovalent H3K4me3 modification at term when the genes are upregulated. Bivalent epigenetic regulation by histone modifying enzymes may control the timing of labour.

Screening for hepatitis C virus infection in methadone-maintained mothers and their infants.

OBJECTIVE: To describe the patterns of screening for hepatitis C virus (HCV) infection in methadone-maintained pregnant women and their infants. DESIGN, SETTING AND PATIENTS: Retrospective review of medical records from one rural and two metropolitan hospitals in New South Wales for pregnant women on methadone maintenance treatment and infants born to these women between 1 January 2000 and 31 December 2006, as well as records for pregnant women who were not on methadone treatment. MAIN OUTCOME MEASURES: Rates of anti-HCV antibody and HCV RNA testing for pregnant women and their infants, and ages at which infants attended follow-up appointments. RESULTS: Of 295 pregnant women on methadone maintenance treatment, 288 were tested for anti-HCV antibodies (98%), compared with 1995 of 9987 women who were not on methadone treatment (20%) (P<0.001). Seropositive results were obtained for 243 women in the methadone group (84%) and 54 in the non-methadone group (3%) (P<0.001), of whom 44 (18%) and 17 (31%), respectively, were subsequently tested for HCV RNA (P=0.03). HCV RNA test results were positive for 31 (70%) and 10 (59%) seropositive women in the methadone and non-methadone groups, respectively (P=0.39). Of infants of HCV-seropositive methadone-maintained mothers, 27% of those for whom we had follow-up attendance data received HCV screening, and one of these infants tested positive for anti-HCV antibodies and HCV RNA. CONCLUSIONS: Screening for HCV infection in the high-risk population of pregnant women on methadone maintenance treatment and their infants is inadequate. This could lead to significant underdetection of active HCV infection in this high-risk population, and their infants. Current screening guidelines may therefore need to be revised.