Parkinson's disease (PD) is a chronic progressive neurodegenerative disorder that is clinically defined in terms of motor symptoms. These are preceded by prodromal non-motor manifestations that prove the systemic nature of the disease. Identifying genes and pathways altered in living patients provide new information on the diagnosis and pathogenesis of sporadic PD. We study changes in gene expression in the blood of 40 sporadic PD patients and 20 healthy controls (Discovery set) by taking advantage of the Affymetrix platform. Patients were at the onset of motor symptoms and before initiating any pharmacological treatment. By applying Ranking-Principal Component Analysis, PUMA and Significance Analysis of Microarrays, gene expression profiling discriminates patients from healthy controls and identifies differentially expressed genes in blood. The majority of these are also present in dopaminergic neurons of the Substantia Nigra, the key site of neurodegeneration. Together with neuronal apoptosis, lymphocyte activation and mitochondrial dysfunction, already found in previous analysis of PD blood and post-mortem brains, we unveiled transcriptome changes enriched in biological terms related to epigenetic modifications including chromatin remodeling and methylation. Candidate transcripts were validated by RT-qPCR in an independent cohort of 12 patients and controls (Validation set). Our data support the use of blood transcriptomics to study neurodegenerative diseases. It identifies changes in crucial components of chromatin remodeling and methylation machineries as early events in sporadic PD suggesting epigenetics as target for therapeutic intervention.
Blood transcriptomics of drug-naïve sporadic Parkinson's disease patients.
Specimen part, Disease
View SamplesErythropoiesis in mammals replenishes the circulating red blood cell (RBC) pool from hematopoietic stem/progenitor cells (HSPCs). Two distinct erythropoietic programs have been described. In the first trimester, hematopoietic precursors in the fetal yolk sac follow a primitive pattern of erythropoiesis. However, in the second trimester, hematopoietic stem cells (HSCs) from the fetal liver and later from the bone marrow differentiate by a definitive program of erythropoiesis to yield enucleated erythrocytes. RBCs can also be derived from human induced pluripotent stem cells (hiPSCs) and can express many of the red cell proteins required for normal erythrocyte function, presaging in vitro RBC production for clinical use. However, expansion and enucleation from hiPSCs is less efficient than with erythroblasts (EBs) derived from adult or cord blood progenitors. We hypothesized that substantial differential gene expression during erythroid development from hiPSCs compared to that from adult blood or cord blood precursors could account for these hitherto unexplained differences in proliferation and enucleation. We have therefore grown EBs from human adult and cord blood progenitors and from hiPSCs. Gene expression during erythroid culture from each erythroblast source was analyzed using algorithms designed to cluster co-expressed genes in an unsupervised manner and the function of differentially expressed genes explored by gene ontology. Using these methods we identify specific patterns of gene regulation for adult- and cord- derived EBs, regardless of the medium used, that are substantially distinct from those observed during the differentiation of EBs from hiPSC progenitors which largely follows a pattern of primitive erythropoiesis.
Distinct gene expression program dynamics during erythropoiesis from human induced pluripotent stem cells compared with adult and cord blood progenitors.
Specimen part
View SamplesUnderstanding the pattern of gene expression and identifying the specific genes expressed during erythropoiesis is crucial for a synthesis of erythroid developmental biology. Here we have isolated four distinct populations of erythroblasts at successive erythropoietin-dependent stages of erythropoiesis including the terminal, pyknotic stage. The transcriptome has been determined using Affymetrix arrays. First, we show that cells sorted by surface expression profile express not only significantly fewer genes than unsorted cells, but also significantly more differences in the expression levels of particular genes between stages than unsorted cells, demonstrating the importance of working with defined cell populations to identify lineage and temporally-specific patterns of gene expression. Second, using standard software and matched filtering we identify eleven differentially regulated genes and one continuously expressed gene previously undetected in erythroid expression studies with unknown roles in erythropoiesis (CA3, CALB1, CTSL2, FKBP1B, GSDMB, ITLN1, LIN7B, RRAD, RUNDC3A, UNQ1887, ZNF805, MYL12B). Finally, using transcription factor binding site analysis we identify potential transcription factors that may regulate gene expression during terminal erythropoiesis. Our stringent lists of differentially regulated and continuously expressed transcripts are a resource for functional studies of erythropoietic protein function and gene regulation.
Global gene expression analysis of human erythroid progenitors.
Specimen part
View SamplesThe undifferentiated state of pluripotent stem cells depends heavily on the culture conditions. We show that a unique combination of small molecules, SMC4, added to culture conditions converts primed pluripotent stem cells to a more nave state. By conducting Affymetix analysis we show of majority of lineage markers are repressed in SMC4 culture.
A novel platform to enable the high-throughput derivation and characterization of feeder-free human iPSCs.
Specimen part, Cell line
View SamplesThis study identifies a transciptomic myometrial profile associated with dystocia in spontanous nulliparous term labour
Identification of a myometrial molecular profile for dystocic labor.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Regulation of the ovarian inflammatory response at ovulation by nuclear progesterone receptor.
No sample metadata fields
View SamplesOvulation requires sequential molecular events and structural remodeling in the ovarian follicle for the successful release of a mature oocyte capable of being fertilised. Critical to this process is progesterone receptor (PGR), a transcription factor highly yet transiently expressed in granulosa cells of preovulatory follicles. Progesterone receptor knockout (PRKO) mice are anovulatory, with a specific and complete defect in follicle rupture. Therefore, this model was used to examine the critical molecular and biochemical mechanisms necessary for successful ovulation.
Regulation of the ovarian inflammatory response at ovulation by nuclear progesterone receptor.
No sample metadata fields
View SamplesOvulation requires sequential molecular events and structural remodeling in the ovarian follicle for the successful release of a mature oocyte capable of being fertilised. Critical to this process is progesterone receptor (PGR), a transcription factor highly yet transiently expressed in granulosa cells of preovulatory follicles. Progesterone receptor knockout (PRKO) mice are anovulatory, with a specific and complete defect in follicle rupture. Therefore, this model was used to examine the critical molecular and biochemical mechanisms necessary for successful ovulation.
Regulation of the ovarian inflammatory response at ovulation by nuclear progesterone receptor.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Constrained release of lamina-associated enhancers and genes from the nuclear envelope during T-cell activation facilitates their association in chromosome compartments.
Specimen part, Time
View SamplesActivation of T-cells induces dramatic changes in genome organisation and gene transcription. Here we identify changes in transcriptional profiles at 8h, 24h and 48 post activation
Constrained release of lamina-associated enhancers and genes from the nuclear envelope during T-cell activation facilitates their association in chromosome compartments.
Specimen part, Time
View Samples