Project description:We developed two novel sperm epigenetic clocks by applying Super Learner, an ensemble machine learning algorithm, to predict age from sperm EPIC array DNA methylation data via individual CpG sites and differentially methylated regions (DMRs). Overall, our cox model showed that one-year increase in our developed sperm epigenetic age (SEA) was associated with up to 15% reduction in couples time-to-pregnancy (TTP).
Project description:Paternal exposure to environmentally-relevant Arctic contaminants induces adverse health outcomes and alters the sperm methylome over three generations.
Project description:We hypothesized that the availability of folate, a soluble B vitamin, would alter the levels of DNA methylation in spermatogenesis with consequences for the sperm epigenome and pregnancy outcomes. We fed male mice with either a folate-deficient or a folate-sufficient diet throughout life. Males fed the folate-deficient diet had offspring with increased birth defects, which included craniofacial and musculoskeletal malformations. These phenotypes corresponded to developmental genes with altered methylation in sperm. To determine if there was transmission of epigenetic effects from sires to offspring, global gene expression levels were assessed in placenta from 18.5 dpc fetuses sired by either a folate-sufficient or folate-deficient male. Gene expression was measured in placenta of 18.5 dpc fetuses sired by either a folate sufficient male (n=4 placentas from different litters and different fathers) or a folate deficient (FD) male (n=4 placentas from different litters and different fathers).
Project description:We hypothesized that the availability of folate, a soluble B vitamin, would alter the levels of DNA methylation in spermatogenesis with consequences for the sperm epigenome and pregnancy outcomes. We fed male mice with either a folate-deficient or a folate-sufficient diet throughout life. Males fed the folate-deficient diet had offspring with increased birth defects, which included craniofacial and musculoskeletal malformations. These phenotypes corresponded to developmental genes with altered methylation in sperm. To determine if there was transmission of epigenetic effects from sires to offspring, global gene expression levels were assessed in placenta from 18.5 dpc fetuses sired by either a folate-sufficient or folate-deficient male.
Project description:The circadian clock controls the expression of nearly 50% of protein coding genes in mice, and most likely in humans as well. Therefore, disruption of the circadian clock is presumed to have serious pathological effects including cancer. However, epidemiological studies on individuals with circadian disruption because of night shift or rotating shift work have produced contradictory data not conducive to scientific consensus as to whether circadian disruption increases the incidence of breast, ovarian, prostate or colorectal cancers. Similarly, genetically engineered mice with clock disruption do not exhibit spontaneous or radiation-induced cancers at higher incidence than wild-type controls. Because many cellular functions including the cell cycle and cell division are, at least in part, controlled by the molecular clock components (CLOCK, BMAL1, CRYs, PERs), it has also been expected that appropriate timing of chemotherapy may increase the efficacy of chemotherapeutic drugs and ameliorate their side effect. However, empirical attempts at chronochemotherapy have not produced beneficial outcomes. Using mice without and with human tumor xenografts, sites of DNA damage and repair following treatment with the anticancer drug cisplatin have been mapped genome-wide at single nucleotide resolution and as a function of circadian time. The data indicate that mechanism-based studies such as these may provide information necessary for devising rational chronochemotherapy regimens.
Project description:Ependymoma, the 3rd most common brain tumor in children, recurs in approximately 50% of patients. There is currently no robust marker that predicts for recurrence, which is a significant clinical problem; We used global gene expression profiling of 19 patient surgical samples obtained at initial diagnosis and with known clinical outcomes to discover novel prognostic markers. Experiment Overall Design: Gene expression profiles were generated from surgical tumor samples using Affymetrix HG-U133plus2 chips. Profiles were divided into recurrent and non-recurrent groups in order to identify differentially expressed genes that were associated with risk of recurrence. In addition, time to progression was correlated with gene expression as a continuous variable in the recurrent group.
Project description:Circadian clocks drive 24-h rhythms of physiology and behavior. The circadian clock of hepatocytes has been shown to regulate glucose metabolism, and we were interested if rescuing liver clock function can reverse metabolic impairments in hyperphagic/obese Clock-D19 mutant mice. We compared transcripomte regulation in livers (at Zeitgeber time ZT10) of wild-type (C57BL/6J) and Clock-D19 mice and Clock-D19 mice with genetic rescue of liver clock function using hydrodynamic tail vein injection of a WT-CLOCK expression plasmid
Project description:Circadian rhythms, governed by the dominant central as well as various peripheral clocks, regulate almost all biological processes, including sleep-wake cycles, hormone secretion, and metabolism. In certain contexts, regulation and function of the peripheral oscillations can be decoupled from the central clock. However, the specific mechanisms underlying muscle-intrinsic clock-dependent modulation of muscle function and metabolism remain unclear. We investigated the outcome of perturbations of the primary and secondary feedback loops of the molecular clock in skeletal muscle by specific gene ablation of Period 2 (Per2) and RAR-related orphan receptor alpha (RORα), respectively. In both models, a dampening of core clock gene oscillation was observed, while the phase was preserved. Moreover, both loops seem involved in the homeostasis of amine groups. Very divergent outcomes were seen for overall muscle gene expression, primarily affecting circadian rhythmicity in the Per2, and non-oscillating genes in the RORα knockouts, leading to distinct outcomes in terms of metabolome and phenotype. These results highlight the entanglement of the molecular clock and muscle plasticity, and allude to specific functions of different clock components, i.e. the primary and secondary feedback loops, in this context. The reciprocal interaction between muscle contractility and circadian clocks might therefore be instrumental to determine a finely tuned adaptation of muscle tissue to perturbations in health and disease.