Project description:Several studies have investigated the gene expression profiles in trisomies 21 and 18 to identify the expression signatures that are characteristic of each of these specific aneuploidy conditions. We hypothesized that the viability of cells with gross genomic imbalances might be associated with the activation of resilience mechanisms that are common to different trisomies and that are reflected by specific shared gene expression patterns. Microarray gene expression analysis of amniocytes from fetuses with trisomy 21 or trisomy 18 was conducted to detect such common expression signatures. Comparative analysis of significantly differentially expressed genes in trisomies 18 and 21 identified 6 dysregulated genes common to both trisomies: OTUD5, ADAMTSL1, TADA2A, PPID, PIAS2, and MAPRE2. These genes are involved in apoptosis, ubiquitination, protein folding, and cell division. Functional analysis demonstrated that both trisomies showed dysregulation of the PI3K/AKT pathway, cell cycle G2/M DNA damage checkpoint regulation, and cell death and survival, as well as inhibition of the upstream regulator TP53. Our data demonstrated that trisomies 18 and 21 share common gene expression signatures, implying that common mechanisms of resilience might be activated in aneuploid cells to resist large genomic imbalances. Studies of other trisomies might further clarify mechanisms activated in trisomy syndromes.
Project description:Background: Among full autosomal trisomies, only trisomies of chromosome 21 (Down syndrome, DS), 18 (Edward syndrome, ES) and 13 (Patau syndrome, PS) are compatible with postnatal survival. But the mechanisms, how a supernumerary chromosome disrupts the normal development and causes specific phenotypes, are still not fully explained. As an alternative to gene dosage effects due to the trisomic chromosome, a genome-wide transcriptional dysregulation has been postulated. The aim of this study was to define the transcriptional changes in trisomy 13, 18, and 21 during early fetal development in order to define whether (1) overexpression of genes of the trisomic chromosome contributes solely to the phenotype, if (2) all genes of the trisomic chromosome are upregulated similarly and whether the ratio of gene expression is in agreement with the gene dosis, (3) whether the different trisomies behave similarly in the characteristics of transcriptional dysregulation, and (4) whether transcriptional pattern can be potentially used in prenatal diagnosis. Methods: Using oligonucleotide microarrays (Affymetrix, U133 Plus 2.0), we analyzed whole genome expression profiles representing 54.000 probe sets in cultured amniocytes (AC) and chorion villus cells (CV) from pregnancies with a normal karyotype and with trisomies of human chromosomes 21, 18 and 13. Findings: We observed a low to moderate up-regulation for a subset of genes of the trisomic chromosomes. Transcriptional level of approximately 12-13 % of the supernumerary chromosome appeared similar to the respective chromosome pair in normal karyotypes. Expression values as well as the expression patterns of genes from the trisomic chromosome can distinguish the respective trisomic samples from euploid controls. A subset of chromosome 21-genes including the DSCR1-gene involved in fetal heart development was consistently up-regulated in different tissues (AC, CV) of trisomy 21 fetuses whereas only minor changes were found for genes of all other chromosomes. In contrast, in trisomy 13 and trisomy 18 vigorous downstream transcriptional changes were found. Interpretation: Global transcriptome analysis for autosomal trisomies 13, 18, and 21 supported a combination of the two major hypotheses. As several transcriptional pathways are altered, complex regulatory mechanisms are involved in the pathogenesis of autosomal trisomies. A genome-wide transcriptional dysregulation was predominantly observed in trisomies 13 and 18, whereas a more to chromosome 21 restricted expression alteration was found in trisomy 21. Keywords: Trisomy, Down syndrome, Patau syndrome, Edward syndrome, microarray, gene expression, amniocytes, chorion villus cells, gene dosage effect, DSCR1
Project description:Background: Among full autosomal trisomies, only trisomies of chromosome 21 (Down syndrome, DS), 18 (Edward syndrome, ES) and 13 (Patau syndrome, PS) are compatible with postnatal survival. But the mechanisms, how a supernumerary chromosome disrupts the normal development and causes specific phenotypes, are still not fully explained. As an alternative to gene dosage effects due to the trisomic chromosome, a genome-wide transcriptional dysregulation has been postulated. The aim of this study was to define the transcriptional changes in trisomy 13, 18, and 21 during early fetal development in order to define whether (1) overexpression of genes of the trisomic chromosome contributes solely to the phenotype, if (2) all genes of the trisomic chromosome are upregulated similarly and whether the ratio of gene expression is in agreement with the gene dosis, (3) whether the different trisomies behave similarly in the characteristics of transcriptional dysregulation, and (4) whether transcriptional pattern can be potentially used in prenatal diagnosis. Methods: Using oligonucleotide microarrays (Affymetrix, U133 Plus 2.0), we analyzed whole genome expression profiles representing 54.000 probe sets in cultured amniocytes (AC) and chorion villus cells (CV) from pregnancies with a normal karyotype and with trisomies of human chromosomes 21, 18 and 13. Findings: We observed a low to moderate up-regulation for a subset of genes of the trisomic chromosomes. Transcriptional level of approximately 12-13 % of the supernumerary chromosome appeared similar to the respective chromosome pair in normal karyotypes. Expression values as well as the expression patterns of genes from the trisomic chromosome can distinguish the respective trisomic samples from euploid controls. A subset of chromosome 21-genes including the DSCR1-gene involved in fetal heart development was consistently up-regulated in different tissues (AC, CV) of trisomy 21 fetuses whereas only minor changes were found for genes of all other chromosomes. In contrast, in trisomy 13 and trisomy 18 vigorous downstream transcriptional changes were found. Interpretation: Global transcriptome analysis for autosomal trisomies 13, 18, and 21 supported a combination of the two major hypotheses. As several transcriptional pathways are altered, complex regulatory mechanisms are involved in the pathogenesis of autosomal trisomies. A genome-wide transcriptional dysregulation was predominantly observed in trisomies 13 and 18, whereas a more to chromosome 21 restricted expression alteration was found in trisomy 21. Experiment Overall Design: The study included the following samples: Three samples with normal chromosomes in Amniocytes (AC) and chorion villus cells (CV) each, three samples with trisomy 13 in AC, three samples with trisomy 18 in CV, and three samples with trisomy 21 in AC and CV each.
Project description:The organization and dynamics of chromatin within the in vivo interphase nucleus and the latter's relationship with transcriptional regulation are still not fully understood. To better understand these relationships, we studied a natural example of chromosomal disorganization: aneuploidy due to trisomies 13, 18 and 21. We hypothesized that the presence of an extra copy of one chromosome alters the CT distribution in the nucleus, which in turn perturbs transcriptional activity. We used microarrays to highlight the overall genome expression changes occurring in amniocytes and fibroblasts carrying a trisomy 13, 18 or 21.
Project description:Trisomy is the presence of one extra copy of an entire chromosome or its part in a cell nucleus. In humans, autosomal trisomies are associated with severe developmental abnormalities leading to embryonic lethality, miscarriage or pronounced deviations of various organs and systems at birth. Trisomies are characterized by alterations in gene expression level not exclusively on the trisomic chromosome, but throughout the genome. Here, we applied high-throughput chromo-some conformation capture technique (Hi-C) to study chromatin 3D structure in human donor chorion cells carrying additional chromosome 13 (Patau syndrome), chromosome 16 (the most common trisomy), and in cultured fibroblasts with extra chromosome 18 (Edwards syndrome). The presence of extra chromosomes 13 and 16, but not 18, results in systematic changes of contact frequencies between small and large chromosomes. Analyzing the behavior of individual chro-mosomes, we determined that a limited number of chromosomes change their contact patterns stochastically in trisomic cells, and that it could be linked to LAD and gene content. We also found that genome regions which are more compacted in trisomic cells are significantly enriched in housekeeping genes that potentially suggest the decrease of chromatin accessibility and tran-scription level. These results provide a framework for understanding the mechanisms of pan-genome transcription dysregulation in trisomies in the context of chromatin spatial organi-zation.
Project description:Mass spectrometry-based quantitative proteomics was used to delineate proteome-wide and extracellular matrix (ECM) alterations at four age groups in human pancreas: fetal (18-20 weeks gestation), juvenile (5-16 years old), young adults (21-29 years old) and older adults (50-61 years old).
Project description:Fetal lung development is a complex biological process, which involves temporal and spatial regulations of many genes. To understand molecular mechanisms of this process, we investigated gene expression profiling of lungs at gestational day 18, 19, 20, 21, new born, and adult rats using in-house rat DNA microarray containing 6,000 known genes and 4,000 ESTs. 1,512 genes passed SAM test and 583 genes (402 known genes and 181 ESTs) had a 2-fold change at least at one time point. K-means cluster analysis revealed 7 major expression patterns. Furthermore, using GeneMapp, we identified 3 regulatory pathways: TGF beta signaling pathway, cell cycle, and G-protein signaling; and 2 metabolism pathways: proteasome degradation and glycolysis. Our results suggest a complex regulatory pathway for fetal lung development. Keywords: Time course
Project description:Phenotypes in chromosome abnormalities do not arise as a mere summation of the specific effects of dosage-sensitive genes, but as a result of the synergistic actions of whole chromosomes. Recent studies on yeast and mammalian cells have demonstrated that aneuploidy exerts detrimental effects on organismal growth and development, regardless of the karyotype, suggesting that aneuploidy-associated stress plays an important role in disease pathogenesis. However, whether and how this effect alters cellular homeostasis and long-term features of human disease are not fully understood. Here, we aimed to investigate cellular stress responses in human trisomy syndromes, using fibroblasts and induced pluripotent stem cells (iPSCs). Dermal fibroblasts derived from patients with trisomy 21, 18 and 13 showed a severe impairment of cell proliferation and enhanced premature senescence. These phenomena were accompanied by perturbation of protein homeostasis, leading to the accumulation of protein aggregates. We found that treatment with sodium 4-phenylbutyrate (4-PBA), a chemical chaperone, decreased the protein aggregates in trisomy fibroblasts. Notably, 4-PBA treatment successfully prevented the progression of premature senescence in secondary fibroblasts derived from trisomy 21 iPSCs. Our study reveals aneuploidy-associated stress as a potential therapeutic target for human trisomies, including Down syndrome.
Project description:Fetal lung development is a complex biological process, which involves temporal and spatial regulations of many genes. To understand molecular mechanisms of this process, we investigated gene expression profiling of lungs at gestational day 18, 19, 20, 21, new born, and adult rats using in-house rat DNA microarray containing 6,000 known genes and 4,000 ESTs. 1,512 genes passed SAM test and 583 genes (402 known genes and 181 ESTs) had a 2-fold change at least at one time point. K-means cluster analysis revealed 7 major expression patterns. Furthermore, using GeneMapp, we identified 3 regulatory pathways: TGF beta signaling pathway, cell cycle, and G-protein signaling; and 2 metabolism pathways: proteasome degradation and glycolysis. Our results suggest a complex regulatory pathway for fetal lung development. Loop Design as following: D18-D19-D20-D21-NB-AD-D18