Project description:<p>Methylmercury is a potent neurotoxin, and the fetal period is the most vulnerable exposure period. There is significant variability in methylmercury metabolism, which has been attributed to differences in the structure and function of the gut microbiome. Our main objective was to better understand the interplay between gut microorganisms and methylmercury metabolism during pregnancy. To address this aim, associations were investigated between maternal biomarkers (blood, hair, stool) for prenatal methylmercury exposure and maternal gut microbiota during early and late gestation.</p>
Project description:Pregnancy has been proposed as a biological “stress test” that may transiently accelerate maternal biological aging, followed by partial recovery in the postpartum period; however, longitudinal evidence characterizing these trajectories remains limited. This longitudinal study followed 130 women across mid to late pregnancy, early postpartum (6–9 months), and later postpartum (36–43 months) to characterize nonlinear changes in multiple markers of biological aging. Biological aging was assessed using complementary indicators, including telomere length, DNA methylation–based epigenetic aging measures, and pace-of-aging metrics. Genome-wide DNA methylation data were generated from maternal biospecimens using the Illumina Infinium MethylationEPIC v2.0 BeadChip to support derivation of epigenetic aging measures and evaluation of longitudinal methylation dynamics. Generalized additive mixed models were used to examine within-person changes over time. Results indicated relative stability or slowing of biological aging during early postpartum, followed by marker-specific patterns of stabilization or decline during later postpartum. Subsequent pregnancy during the later postpartum period was associated with shorter telomere length and altered recovery trajectories, including accelerated pace of aging among women who became pregnant again. Together, these findings suggest that while partial recovery of biological aging markers may occur following pregnancy, such recovery may be sensitive to additional reproductive demands. The DNA methylation data deposited here support longitudinal analyses of maternal biological aging across pregnancy and postpartum and provide a resource for future studies examining reproductive influences on epigenetic aging processes. Additional study data available via figshare at: https://doi.org/10.6084/m9.figshare.30005287
Project description:This study aims at investigating the effects of methylmercury on a microalga using a transcriptomic approach. Algal cells were exposed two hours in a simplified artificial medium spiked with 0.05 or 0.5 nM MeHg. Total RNA was extracted using TRI Reagent®. Libraries were prepared with the Illumina TruSeq Stranded mRNA kit and sequenced on an Illumina HiSeq 2500 System.
Project description:Methylmercury is known as the causative agent of Minamata disease. To investigate the mechanisms of neurotoxicity in the dorsal root ganglion, male Wistar rats (8 weeks old) were administered methylmercury (6.7 mg/kg/day) for five consecutive days followed by two days without treatment, repeated over a two-week period. Dorsal root ganglia were collected from the control group, as well as on days 7 and 14 after the start of administration. Total RNA was extracted and subjected to DNA microarray analysis. In the day-7 samples, marked alterations in gene groups involved in inflammatory responses were observed, while in the day-14 samples, in addition to these changes, alterations in approximately 15,000 gene groups were detected.
Project description:To characterize the human plasma microtranscriptome profile at first trimester of pregnancy in presence or not of pregnancy complications, we sequenced microRNAs in plasma samples collected from pregnant women between the 4th and the 16th weeks of pregnancy. We then performed differential expression analyses to assess the miRNA profile diffrences according to the presence of pregnancy complications or not (i.e. Gestational diabetes mellitus, Gestational hypertension or preeclampsia vs. normal pregnancies).