Project description:Pregnancy loss is often caused by chromosomal abnormalities of the conceptus. The prevalence of these abnormalities and the allocation of (ab)normal cells in embryonic and placental lineages during intrauterine development remain elusive. We analyzed 1,745 spontaneous pregnancy losses and found that roughly half (50.4%) of the products of conception (POC) were karyotypically abnormal, with maternal and paternal age independently contributing to the increased genomic aberration rate in pregnancy loss. We applied genome haplarithmisis to a subset of 94 pregnancy losses with normal parental and POC karyotypes. Genotyping of parental DNA as well as POC extraembryonic mesoderm and chorionic villi DNA, representing embryonic and trophoblastic tissues, enabled characterization of the genomic landscape of both lineages. Of these pregnancy losses, 35.1% had chromosomal aberrations not previously detected by karyotyping, increasing the rate of aberrations of pregnancy losses to 67.8% by extrapolation. In contrast to viable pregnancies where mosaic chromosomal abnormalities are often restricted to chorionic villi, such as confined placental mosaicism, we found a higher degree of mosaic chromosomal imbalances in extraembryonic mesoderm rather than chorionic villi in pregnancy losses. Our results stress the importance of scrutinizing the full allelic architecture of genomic abnormalities in pregnancy loss to improve clinical management and basic research of this devastating condition.
Project description:Neural imaging, genetics, and circulating biomarkers are being developed to differentiate normal aging from diseases that affect cognition. The blood based biomarkers, such as plasma exosome could provide a simple and relatively inexpensive means for tracking the progression of cognitive decline and effectiveness of treatments, as well as providing information on mechanism for cognitive impairment.
Project description:Pregnancy is the major modulator of mammary gland activity. It induces a tremendous expansion of the mammary epithelium and the generation of alveolar structures for milk production. Anecdotal evidence from multiparous humans indicates that the mammary gland may react less strongly to the first pregnancy than it does to subsequent pregnancies. Here we verify that the mouse mammary gland responds more robustly to a second pregnancy, indicating that the gland retains a long-term memory of pregnancy. A comparison of genome-wide profiles of DNA methylation in isolated mammary cell types revealed substantial and long lasting alterations. The majority of these alterations affect sites occupied by the Stat5a transcription factor and mark specific genes that are upregulated during pregnancy. We postulate that the epigenetic memory of a first pregnancy primes the activation of gene expression networks that promote mammary gland function in subsequent reproductive cycles. More broadly, our data indicate that physiological experience can broadly alter epigenetic states, functionally modifying the capacity of the affected cells to respond to later stimulatory events. Mammary gland cells (six distinct cell types) from nulliparous and parous female mice were FACS-sorted using a combination of cell surface markers. Genomic DNA was bisulfite converted and used to obtain genome-wide DNA methylation profiles. The current work focuses on the analysis of the first 12 samples (GSM1646785-96) and uses the other two samples to confirm some properties of the analysis results based on samples 1-12. Consequently, samples GSM1646797, GSM1646798 were analyzed in a much more limited manner compared to the other 12 samples, generating two plots included in the associated manucript.
Project description:The aim of this study was to compare the mutational landscape of breast cancer diagnosed during pregnancy (BCP) and breast cancer from age/stage non-pregnant patients (controls). We present whole genome sequencing data (Illumina HiSeq X ten platform) of tumor and matched normal tissues from 35 BCP patients and 20 controls. This work provides important novel biological insights and a unique resource to study the biology of breast cancer in young women and how pregnancy could modulate tumor biology.
Project description:Emerging evidence has revealed alterations of microRNA (miRNA) profiles in peripheral blood associated to changes in a range of physiological conditions, suggesting that circulating miRNA profiles could be used as prognostic and/or diagnostic biomarkers for a wide variety of clinical conditions. Normal human pregnancy poses an extensive number of physiological challenges, affecting virtually every level of the pregnant woman’s biology, as well as changing contributions of the placenta and fetus. In this cohort study, using longitudinal large-scale profiling of circulating miRNAs at four defined stages during and after normal pregnancy, relative to non-pregnant controls, we investigate temporal changes in miRNA profiles as potential biomarkers of pregnancy evolution. By comparing the profiling of blood plasma miRNAs with available expression data, we found that miRNAs most prominently expressed in key reproductive tissues are collectively down regulated throughout pregnancy. Furthermore, we find a bias in the proportion of differentially expressed miRNAs associated with fetal sex right from the first trimester. Lastly, by combining circulating miRNAs expression with fetal growth indicators derived from the same women, we identify a robust miRNA signature associated to fetal growth during normal pregnancy. Our results demonstrate the existence of temporal changes of specific miRNAs associated to distinct aspects of pregnancy, including correlates of placental function, fetal gender, and fetal growth, as well as an early lactation related signature; strongly suggesting the potential of peripheral miRNAs as biomarkers of normal pregnancy.
Project description:Low fertility remains a leading cause of poor productivity in dairy cattle. In this context, there is significant interest in developing novel tools for accurate early diagnosis of pregnancy. MicroRNAs (miRNAs) are short RNA molecules which are critically involved in regulating gene expression during both health and disease. MiRNAs have been shown to regulate ovarian function, uterine receptivity, embryonic development and placental function. Circulating miRNAs can provide useful biomarkers of tissue function and disease; importantly, differential miRNA profiles have been linked to pregnancy and preeclampsia in humans. This study sought to establish the potential of circulating miRNAs as biomarkers of early pregnancy in cattle. We applied Illumina small-RNA sequencing to profile miRNAs in plasma samples collected from eight non-pregnant heifers on Days 0, 8 and 16 of the oestrous cycle and 11 heifers on Days 16 and 24 of pregnancy. We sequenced a total of 46 samples and generated 9.2 million miRNA reads per sample. There were no differences in miRNA read abundance between any of the pregnant and non-pregnant time-points (FDR > 0.1). As a complementary approach, we analysed sample pools (3-4 samples/pool) corresponding to Days 0, 8 and 16 of the oestrous cycle and Day 24 of pregnancy (n = 3 pools/group) using Qiagen PCR arrays. A total of 16 miRNAs were differentially expressed (FDR < 0.1) in plasma between pregnant and non-pregnant animals. RT-qPCR validation using the same plasma samples confirmed that miR-26a was differentially upregulated on Day 16 pregnant relative to non-pregnant heifers (1.7-fold; P = 0.043), whereas miR-1249 tended to be upregulated in Day 16 pregnant heifers (1.6-fold; P = 0.081). Further validation in an independent group of heifers confirmed an increase in plasma miR-26a levels during early pregnancy, which was significant only on Day 24 (2.0-fold; P = 0.027). Through genome-wide analyses we have successfully profiled plasma miRNA populations associated with early pregnancy in cattle. We have identified miR-26a as a potential circulating biomarker of early pregnancy.
Project description:Pregnancy is the major modulator of mammary gland activity. It induces a tremendous expansion of the mammary epithelium and the generation of alveolar structures for milk production. Anecdotal evidence from multiparous humans indicates that the mammary gland may react less strongly to the first pregnancy than it does to subsequent pregnancies. Here we verify that the mouse mammary gland responds more robustly to a second pregnancy, indicating that the gland retains a long-term memory of pregnancy. A comparison of genome-wide profiles of DNA methylation in isolated mammary cell types revealed substantial and long lasting alterations. The majority of these alterations affect sites occupied by the Stat5a transcription factor and mark specific genes that are upregulated during pregnancy. We postulate that the epigenetic memory of a first pregnancy primes the activation of gene expression networks that promote mammary gland function in subsequent reproductive cycles. More broadly, our data indicate that physiological experience can broadly alter epigenetic states, functionally modifying the capacity of the affected cells to respond to later stimulatory events.
Project description:Poor reproductive performance remains a major issue in the dairy industry, with extremely low calving rates (34 %) affecting milk production, profitability and the economy in general. Early pregnancy detection can help identify non-pregnant animals within three weeks of insemination, minimizing delays and shortening calving intervals. However current pregnancy detection methods are not accurate enough to support such reproductive management programs. MiRNAs have been proposed as non-invasive biomarkers of pregnancy and several reproductive diseases in humans. We previously identified miR-26a as a potential early pregnancy biomarker in cattle. In the current study, using miRNA sequencing, we identified and validated differentially expressed miRNAs on Day 60 of pregnancy compared to Day 0 (non-pregnant), and we investigated the expression of these validated miRNAs in early pregnancy aiming to identify additional early pregnancy biomarker candidates. The expression levels of selected miRNAs which are differentially expressed during pregnancy will also be investigated as part of this study.
Project description:Primary, this study aims to develop and validate a computer-aided diagnosis (CADx) system for the characterization of colorectal polyps.
Second, this study evaluates the effect of using a clinical classification model Blue Light Imaging Adenoma Serrated International (BASIC) on the diagnostic accuracy of the optical diagnosis of colorectal polyps compared to intuitive optical diagnosis for both expert endoscopists and novices.