Anti-PER1 polyclonal antibody

Background and purpose: Several members of the core clock mechanism are equipped with a Per-Arnt-Sim (PAS) domain through which they can bind haem [Fe(II)]. Haem is a ligand for the orphan receptors REV-ERB alpha/beta (NR1D1/2), which regulate circadian rhythm and metabolism. The ability to bind haem sensitises these clock components to the action of small molecule gases, including NO, CO and H2S. Studies conducted with European hamsters revealed that during winter sleep, key clock genes stop oscillating. At the same time, H2S, when administered at subtoxic concentrations, can induce a hypometabolic state in the cell. We suppose that core clock components, including the nuclear receptors REV-ERBs, neuronal PAS domain protein 2 (nPAS2) and PER2, can be H2S targets. The general objective of this study was to investigate the effect of the H2S system on the expression profile of the core clock genes in cells in vitro. Experimental approach: We analysed the expression of Per1, Per2, Per3, Bmal1, Cry1, Cry2, Nr1d1, Nfil-3 and Dbp messenger RNA (mRNA) in serum-shocked NIH-3T3 cells treated with a slow-releasing H2S donor (GYY4137) or the cystathionine beta-synthase (CBS) inhibitor (AOAA) cultured under constant darkness and collected during 3 days in 3 h interval. Key results and conclusions and implications: We found that pharmacological CBS inhibition increased the general expression and dynamics of several clock genes. On the other hand, increased H2S decreased Per2 expression. These data suggest that CBS can affect circadian clock and effect on clock-controlled transcription output.

In mammals, a central clock maintains the daily rhythm in accordance with the external environment. At the molecular level, the circadian rhythm is maintained by epigenetic regulation of the Circadian pathway. Here, we tested the role of particulate matter with an aerodynamic diameter <= 2.5 mu m (PM2.5) exposure during gestational life on human placental Circadian pathway methylation, as an important molecular target for healthy development. In 407 newborns, we quantified placental methylation of CpG sites within the promoter regions of the following genes: CLOCK, BMAL1, NPAS2, CRY1-2 and PER1-3 using bisulfite-PCR-pyrosequencing. Daily PM2.5 exposure levels were estimated for each mother's residence, using a spatiotemporal interpolation model. We applied mixed-effects models to study the methylation status of the Circadian pathway genes and in utero PM2.5 exposure, while adjusting for a priori chosen covariates. In a multi-gene model, placental Circadian pathway methylation was positively and significantly (p < 0.0001) associated with 3rd trimester PM2.5 exposure. Consequently, the single-gene models showed relative methylation differences [Log(fold change)] in placental NPAS2 (+0.16; p = 0.001), CRY1 (+0.59; p = 0.0023), PER2 (+0.36; p = 0.0005), and PER3 (+0.42; p = 0.0008) for an IQR increase (8.9 mu g/m(3)) in 3rd trimester PM2.5 exposure. PM2.5 air pollution, an environmental risk factor leading to a pro-inflammatory state of the mother and foetus, is associated with the methylation pattern of genes in the Circadian pathway. The observed alterations in the placental CLOCK epigenetic signature might form a relevant molecular mechanism through which fine particle air pollution exposure might affect placental processes and foetal development.