Project description:We have identified effects of elevated maternal cortisol on fetal cardiac maturation and function in an ovine model. Whereas short term exposure, produced by maternal infusion (1 mg/kg/d) from 115-130d gestation increased fetal heart wall thickness and weight, myocyte proliferation and Purkinje fiber apoptosis, when cortisol exposure continued until term (~145 days of gestation), there was a profound increase in perinatal stillbirth. Further study indicated increases in P-R and R-R interval of the ECG and increased incidence of arrhythmias at birth, suggesting that these changes in the fetal heart contribute to the stillbirth. We have used systems biology to statistically model the transcriptomic changes in hearts at 130 days and near term. In the current study, we used this approach to test for effects on pathways related to metabolism and cardiac structure in the left ventricle and septum from newborn lambs. Cortisol altered genes in pathways involved in cardiac architecture in the left ventricle, including SMAD and BMP; cortisol also increased collagen deposition. Genes in pathways involved in metabolism and actin filament assembly were affected within the septum. Comparison of the effects of cortisol to the effects of normal maturation from day 140 to birth revealed that only 1% of the genes changed by cortisol in the LV and 18% in the septum were consistent with the normal maturational changes in gene expression. These results indicate that chronic in utero exposure to elevated cortisol concentrations alters the normal maturation of the fetal myocardium, adversely impacting perinatal cardiac function.
Project description:Poor maternal nutrition causes intrauterine growth restriction (IUGR); however, its effects on fetal cardiac development are unclear. We have developed a baboon model of moderate maternal undernutrition, leading to IUGR. We hypothesized that the IUGR affects fetal cardiac structure and metabolism. Six control pregnant baboons ate ad-libitum (CTRL)) or 70% CTRL from 0.16 of gestation (G). Fetuses were euthanized at C-section at 0.9G under general anesthesia. Male but not female IUGR fetuses showed left ventricular fibrosis inversely correlated with birth weight. Expression of extracellular matrix protein TSP-1 was increased (p<0.05) in male IUGR. Expression of cardiac fibrotic markers TGFß, SMAD3 and ALK-1 were downregulated in male IUGRs with no difference in females. Autophagy was present in male IUGR evidenced by upregulation of ATG7 expression and lipidation LC3B. Global miRNA expression profiling revealed 56 annotated and novel cardiac miRNAs exclusively dysregulated in female IUGR, and 38 cardiac miRNAs were exclusively dysregulated in males (p<0.05). Fifteen (CTRL) and 23 (IUGR) miRNAs, were differentially expressed between males and females (p<0.05) suggesting sexual dimorphism, which can be at least partially explained by differential expression of upstream transcription factors (e.g. HNF4a, and NF?B p50). Lipidomics analysis of fetal cardiac tissue exhibited a net increase in diacylglycerol and plasmalogens and a decrease in triglycerides and phosphatidylcholines. In summary, IUGR resulting from decreased maternal nutrition is associated with sex-dependent dysregulations in cardiac structure, miRNA expression, and lipid metabolism. If these changes persist postnatally, they may program offspring for higher later life cardiac risk.
Project description:To investigate the differentiative fate of human PLCs following transplantation into fetal sheep and engraftment in various tissues/organs, we performed gene expression profiling analysis using data obtained from RNA-seq of human PLCs prior to in utero transplantation and of each engrafted fetal sheep tissue after filtering to remove any cross-reactivity with orthologous sheep transcripts
Project description:In humans and other species, Longlong-term hypoxia (LTH) during pregnancy can lead to intrauterine growth restriction with reduced body/brain weight, dysregulation of cerebral blood flow (CBF), and other problems in humans and rodents. In contrast, sheep appear to undergo relatively successful acclimatization, not demonstrating any of the above-mentioned problems except at extremely high altitude. To identify the signal transduction genetic pathways and those critical molecules, which may be involved in acclimatization to high altitude LTH, we conducted microarray with advanced bioinformatic analysis on carotid arteries (CA) from the normoxic near-term ovine fetus at sea-level and those acclimatized to high altitude for 110+ days during gestation. In response to LTH acclimatization, in fetal CA we identified, mRNA from 38 genes upregulated (> 2 fFold; (P < 0.05) and 9 genes downregulated (> 2-f Fold; (P < 0.05). The major genes with upregulated mRNA were SLC1A3, Insulin-like growth factor (IGF) binding protein 3, IGF type 2 receptor, transforming growth factor (TGF) Beta-3, and genes involved in the AKT and BCL2 signal transduction networks. The majority of genes with upregulated mRNA have a common motif for Pbx/Knotted homeobox in the promoter region, and Sox family binding sites in the 3M-bM-^@M-^Y un -translated region (UTR). Genes with downregulated mRNA included those involved in the P53 pathway and 5-lipoxygenase activating proteins. The promoter region of all genes with downregulated mRNA, had a common 49 bp region, with a binding site for DOT6 and TOD6, components of the RPD3 histone deacetylase complex RPD3C(L). We also identified miRNA complementary to a number of the altered genes. Thus, the present study identified molecules in the ovine fetus, which may help it to play a role in the acclimatizatione successfully response to high-altitude associated LTH. In these series of experiments we examined changes in gene expression in sheep carotids. Pregnant sheep and non-pregnant adult sheep were exposed to 110 days of hypoxia at 3801 meters of altitude. Carotid arteries from fetuses from non-pregnant adult from sea-level controls and those from high-altitude were compared by Agilent ovine custom array
Project description:Children born to diabetic and obese or overweight mothers have a higher risk of heart disease at birth and later in life. Our previous work using chromatin immunoprecipitation sequencing revealed that late-gestation diabetes in combination with maternal high fat diet causes a distinct fuel-mediated epigenetic reprogramming of cardiac tissue during fetal cardiogenesis. We used gene expression profiling to investigate the overall transcriptional signature of newborn rat offspring exposed to the combination of maternal diabetes and maternal high fat diet.
Project description:The instrinsic regenerative capacity of human fetal cardiac mesenchymal stromal cells (MSCs) has not been fully characterised. Here we demonstrate that we can expand cells with characteristics of cardiovascular progenitor cells from the MSC population of human fetal hearts with only minor fluctuations over time in culture (from day 15 to day 48). We used microarray to compare the gene-expression profile of cultured human fetal cardiac MSCs over time (from day 15 to day 48). MSCs from human fetal hearts were cultured on GelTrex in a defined medium stimulating the canonical Wnt/beta-catenin pathway. Samples from three different time points (day 15, 27 and 48) were compared on microarray.
Project description:The instrinsic regenerative capacity of human fetal cardiac mesenchymal stromal cells (MSCs) has not been fully characterised. Here we demonstrate that we can expand cells with characteristics of cardiovascular progenitor cells from the MSC population of human fetal hearts with only minor fluctuations over time in culture (from day 15 to day 48). We used microarray to compare the gene-expression profile of cultured human fetal cardiac MSCs over time (from day 15 to day 48).