scholarly journals Discovery and characterization of variance QTLs in human induced pluripotent stem cells

2018 ◽  
Author(s):  
Abhishek K. Sarkar ◽  
Po-Yuan Tung ◽  
John D. Blischak ◽  
Jonathan E. Burnett ◽  
Yang I. Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Genetic Variation ◽  
Single Cell ◽  
Pluripotent Stem Cells ◽  
Human Tissues ◽  
Rna Seq ◽  
Induced Pluripotent ◽  
Expression Variance ◽  
Gene Expression Levels

AbstractQuantification of gene expression levels at the single cell level has revealed that gene expression can vary substantially even across a population of homogeneous cells. However, it is currently unclear what genomic features control variation in gene expression levels, and whether common genetic variants may impact gene expression variation. Here, we take a genome-wide approach to identify expression variance quantitative trait loci (vQTLs). To this end, we generated single cell RNA-seq (scRNA-seq) data from induced pluripotent stem cells (iPSCs) derived from 53 Yoruba individuals. We collected data for a median of 95 cells per individual and a total of 5,447 single cells, and identified 241 mean expression QTLs (eQTLs) at 10% FDR, of which 82% replicate in bulk RNA-seq data from the same individuals. We further identified 14 vQTLs at 10% FDR, but demonstrate that these can also be explained as effects on mean expression. Our study suggests that dispersion QTLs (dQTLs) which could alter the variance of expression independently of the mean can have larger fold changes, but explain less phenotypic variance than eQTLs. We estimate 424 individuals as a lower bound to achieve 80% power to detect the strongest dQTLs in iPSCs. These results will guide the design of future studies on understanding the genetic control of gene expression variance.Author summaryCommon genetic variation can alter the level of average gene expression in human tissues, and through changes in gene expression have downstream consequences on cell function, human development, and human disease. However, human tissues are composed of many cells, each with its own level of gene expression. With advances in single cell sequencing technologies, we can now go beyond simply measuring the average level of gene expression in a tissue sample and directly measure cell-to-cell variance in gene expression. We hypothesized that genetic variation could also alter gene expression variance, potentially revealing new insights into human development and disease. To test this hypothesis, we used single cell RNA sequencing to directly measure gene expression variance in multiple individuals, and then associated the gene expression variance with genetic variation in those same individuals. Our results suggest that effects on gene expression variance are smaller than effects on mean expression, relative to how much the phenotypes vary between individuals, and will require much larger studies than previously thought to detect.

scholarly journals Single cell eQTL analysis identifies cell type-specific genetic control of gene expression in fibroblasts and reprogrammed induced pluripotent stem cells

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Drew Neavin ◽  
Quan Nguyen ◽  
Maciej S. Daniszewski ◽  
Helena H. Liang ◽  
Han Sheng Chiu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Population Genetics ◽  
Genetic Variation ◽  
Single Cell ◽  
Pluripotent Stem Cells ◽  
Individual Cell ◽  
Cell Type ◽  
Cell Type Specific ◽  
Induced Pluripotent

Abstract Background The discovery that somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) has provided a foundation for in vitro human disease modelling, drug development and population genetics studies. Gene expression plays a critical role in complex disease risk and therapeutic response. However, while the genetic background of reprogrammed cell lines has been shown to strongly influence gene expression, the effect has not been evaluated at the level of individual cells which would provide significant resolution. By integrating single cell RNA-sequencing (scRNA-seq) and population genetics, we apply a framework in which to evaluate cell type-specific effects of genetic variation on gene expression. Results Here, we perform scRNA-seq on 64,018 fibroblasts from 79 donors and map expression quantitative trait loci (eQTLs) at the level of individual cell types. We demonstrate that the majority of eQTLs detected in fibroblasts are specific to an individual cell subtype. To address if the allelic effects on gene expression are maintained following cell reprogramming, we generate scRNA-seq data in 19,967 iPSCs from 31 reprogramed donor lines. We again identify highly cell type-specific eQTLs in iPSCs and show that the eQTLs in fibroblasts almost entirely disappear during reprogramming. Conclusions This work provides an atlas of how genetic variation influences gene expression across cell subtypes and provides evidence for patterns of genetic architecture that lead to cell type-specific eQTL effects.

scholarly journals Modelling the developmental spliceosomal craniofacial disorder Burn-McKeown syndrome using induced pluripotent stem cells

2020 ◽  
Author(s):  
Katherine A. Wood ◽  
Charlie F. Rowlands ◽  
Huw B. Thomas ◽  
Steven Woods ◽  
Julieta O’Flaherty ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Craniofacial Development ◽  
Rna Seq ◽  
Unrelated Control ◽  
Mesenchymal Transition ◽  
Base Pair Deletion ◽  
Induced Pluripotent

ABSTRACTThe craniofacial developmental disorder Burn-McKeown Syndrome (BMKS) is caused by biallelic variants in the pre-messenger RNA splicing factor gene TXNL4A/DIB1. The majority of affected individuals with BMKS have a 34 base pair deletion in the promoter region of one allele of TXNL4A combined with a loss-of-function variant on the other allele, resulting in reduced TXNL4A expression. However, it is unclear how reduced expression of this ubiquitously expressed spliceosome protein results in craniofacial defects during development. Here we reprogrammed peripheral mononuclear blood cells from a BMKS patient and her unaffected mother into induced pluripotent stem cells (iPSCs) and differentiated the iPSCs into induced neural crest cells (iNCCs), the key cell type required for correct craniofacial development. BMKS patient-derived iPSCs proliferated more slowly than both mother- and unrelated control-derived iPSCs, and RNA-Seq analysis revealed significant differences in gene expression and alternative splicing. Patient iPSCs displayed defective differentiation into iNCCs compared to maternal and unrelated control iPSCs, in particular a delay in undergoing an epithelial-to-mesenchymal transition (EMT). RNA-Seq analysis of differentiated iNCCs revealed widespread gene expression changes and mis-splicing in genes relevant to craniofacial and embryonic development that highlight a dampened response to WNT signalling, the key pathway activated during iNCC differentiation. Furthermore, we identified the mis-splicing of TCF7L2 exon 4, a key gene in the WNT pathway, as a potential cause of the downregulated WNT response in patient cells. Additionally, mis-spliced genes shared common sequence properties such as length, splice site strengths and sequence motifs, suggesting that splicing of particular subsets of genes is particularly sensitive to changes in TXNL4A expression. Together, these data provide the first insight into how reduced TXNL4A expression in BMKS patients might compromise splicing and NCC function, resulting in defective craniofacial development in the embryo.

scholarly journals Large-Scale Profiling Reveals the Influence of Genetic Variation on Gene Expression in Human Induced Pluripotent Stem Cells

2017 ◽  
Vol 20 (4) ◽  
pp. 533-546.e7 ◽  
Author(s):  
Christopher DeBoever ◽  
He Li ◽  
David Jakubosky ◽  
Paola Benaglio ◽  
Joaquin Reyna ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Genetic Variation ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Large Scale ◽  
Induced Pluripotent

Abstract P418: Transcriptomic And Genomic DNA Accessibility Dynamics During Differentiation Of Induced Pluripotent Stem Cells Derived Smooth Muscle Cells And Acquisition Of Contractile Phenotype

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
LU LIU ◽  
Adrien Georges ◽  
Nabila Bouatia-Naji
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Contractile Function ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Human Aorta ◽  
Rna Seq ◽  
Dna Accessibility ◽  
Induced Pluripotent

Introduction: Smooth muscle cells (SMCs) capacity to phenotype switching between proliferative and quiescent (contractile) is a widely studied mechanism in cardiovascular disease. Primary SMCs tend to lose many physiological features in culture, which makes the study of their contractile function challenging. Recently, an optimized protocol of induced pluripotent stem cells (iPSCs) differentiation into contractile SMCs was described. Here we aimed at defining the transcriptomic and open chromatin dynamics during the acquisition of SMCs phenotypes. Methods: We differentiated 4 human iPSC lines (2 males, 2 females) towards either contractile (Repsox induced) or synthetic (PDGF-BB/TGF-β induced) SMC phenotypes using a 24-days protocol. We performed RNA-Seq and assay for transposase accessible chromatin (ATAC)-Seq at 5 time points of differentiation. We analyzed gene expression profiles and compared them to existing dataset of human aorta by principle component analyses (PCA) and gene set enrichment analyses using GO terms. Results: iPSCs derived SMCs showed expected morphology and positive expression of SMC markers. Synthetic SMCs (SSMCs) exhibited greater capacity of proliferation, migration and lower calcium release capacity, compared to contractile SMCs (CSMCs). RNA-Seq results showed that multiple genes involved in the contractile function of arteries, including myosin light chain kinase (MYLK) and angiotensin type 1 receptor ( AGTR1 ) genes were highly expressed in CSMCs compared to SSMCs. Overall, CSMCs conserved SMC properties beyond 24 days and their gene expression profile clustered near human aorta. During late differentiation stages, CSMCs showed an upregulation of genes involved in cardiovascular system development, whereas genes involved in cell stress were upregulated in SSMCs. Conclusions: We describe global genomic profiles of iPSCs derived CSMCs that presented comparable gene expression profiles to mature artery tissue. Combination with upcoming DNA accessibility maps is expected to allow the functional exploration of genetic risk variation involved in several arterial diseases involving the impairment of the SMCs contractile function.

scholarly journals Single-cell RNA-seq of human induced pluripotent stem cells reveals cellular heterogeneity and cell state transitions between subpopulations

2018 ◽  
Vol 28 (7) ◽  
pp. 1053-1066 ◽  
Author(s):  
Quan H. Nguyen ◽  
Samuel W. Lukowski ◽  
Han Sheng Chiu ◽  
Anne Senabouth ◽  
Timothy J.C. Bruxner ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Single Cell ◽  
Pluripotent Stem Cells ◽  
Cellular Heterogeneity ◽  
State Transitions ◽  
Rna Seq ◽  
Cell State ◽  
Induced Pluripotent

scholarly journals Single cell eQTL analysis identifies cell type-specific genetic control of gene expression in fibroblasts and reprogrammed induced pluripotent stem cells

2020 ◽  
Author(s):  
Drew Neavin ◽  
Quan Nguyen ◽  
Maciej S. Daniszewski ◽  
Helena H. Liang ◽  
Han Sheng Chiu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Variation ◽  
Single Cell ◽  
Pluripotent Stem Cells ◽  
Cell Types ◽  
Cell Type ◽  
Single Cell Rna Sequencing ◽  
Cell Type Specific ◽  
Induced Pluripotent

AbstractThe discovery that somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) - cells that can be differentiated into any cell type of the three germ layers - has provided a foundation for in vitro human disease modelling1,2, drug development1,2, and population genetics studies3,4. In the majority of instances, the expression levels of genes, plays a critical role in contributing to disease risk, or the ability to identify therapeutic targets. However, while the effect of the genetic background of cell lines has been shown to strongly influence gene expression, the effect has not been evaluated at the level of individual cells. Differences in the effect of genetic variation on the gene expression of different cell-types, would provide significant resolution for in vitro research using preprogramed cells. By bringing together single cell RNA sequencing15–21 and population genetics, we now have a framework in which to evaluate the cell-types specific effects of genetic variation on gene expression. Here, we performed single cell RNA-sequencing on 64,018 fibroblasts from 79 donors and we mapped expression quantitative trait loci (eQTL) at the level of individual cell types. We demonstrate that the large majority of eQTL detected in fibroblasts are specific to an individual sub-type of cells. To address if the allelic effects on gene expression are dynamic across cell reprogramming, we generated scRNA-seq data in 19,967 iPSCs from 31 reprogramed donor lines. We again identify highly cell type specific eQTL in iPSCs, and show that that the eQTL in fibroblasts are almost entirely disappear during reprogramming. This work provides an atlas of how genetic variation influences gene expression across cell subtypes, and provided evidence for patterns of genetic architecture that lead to cell-types specific eQTL effects.

scholarly journals T9. EPIGENETIC PROFILING IN SCHIZOPHRENIA DERIVED HUMAN INDUCED PLURIPOTENT STEM CELLS (HIPSCS) AND NEURONS

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S234-S234
Author(s):  
Lorna Farrelly ◽  
Shuangping Zhang ◽  
Erin Flaherty ◽  
Aaron Topol ◽  
Nadine Schrode ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mass Spectrometry ◽  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Neural Progenitor Cells ◽  
Gene Expression Pattern ◽  
Early Gene ◽  
Label Free ◽  
Induced Pluripotent

Abstract Background Schizophrenia (SCZ) is a severe psychiatric disorder affecting ~1% of the world’s population. It is largely heritable with genetic risk reflected by a combination of common variants of small effect and highly penetrant rare mutations. Chromatin modifications are known to play critical roles in the mediation of many neurodevelopmental processes, and, when disturbed, may also contribute to the precipitation of psychiatric disorders, such as SCZ. While a handful of candidate-based studies have measured changes in promoter-bound histone modifications, few mechanistic studies have been carried out to explore how these modifications may affect chromatin to precipitate behavioral phenotypes associated with the disease. Methods We applied an unbiased proteomics approach to evaluate the epigenetic landscape of SCZ in human induced pluripotent stem cells (hiPSC), neural progenitor cells (NPCs) and neurons from SCZ patients vs. matched controls. We utilized proteomics-based, label free liquid chromatography mass spectrometry (LC-MS/MS) on purified histones from these cells and confirmed our results by western blotting in postmortem SCZ cortical brain tissues. Furthermore we validated our findings with the application of histone interaction assays and structural and biophysical assessments to identify and confirm novel chromatin ‘readers’. To relate our findings to a SCZ phenotype we used a SCZ rodent model of prepulse inhibition (PPI) to perform pharmacological manipulations and behavioral assessments. Results Using label free mass spectrometry we performed PTM screening of hiPSCs, NPCs and matured neurons derived from SCZ patients and matched controls. We identified, amongst others, altered patterns of hyperacetylation in SCZ neurons. Additionally we identified enhanced binding of particular acetylation ‘reader’ proteins. Pharmacological inhibition of such proteins in an animal model of amphetamine sensitization ameliorated PPI deficits further validating this epigenetic signature in SCZ. Discussion Recent evidence indicates that relevance and patterns of acetylation in epigenetics advances beyond its role in transcription and small molecule inhibitors of these aberrant interactions hold promise as useful therapeutics. This study identifies a role for modulating gene expression changes associated with a SCZ epigenetic signature and warrants further investigation in terms of how this early gene expression pattern perhaps determines susceptibility or severity of the SCZ disease trajectory.

scholarly journals Batch effects and the effective design of single-cell gene expression studies

2016 ◽  
Author(s):  
Po-Yuan Tung ◽  
John D. Blischak ◽  
Chiaowen Joyce Hsiao ◽  
David A. Knowles ◽  
Jonathan E. Burnett ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Induced Pluripotent Stem Cell ◽  
Expression Levels ◽  
Amplification Bias ◽  
Expression Studies ◽  
Cell Gene Expression ◽  
Gene Expression Studies ◽  
Induced Pluripotent ◽  
Gene Expression Levels

AbstractSingle cell RNA sequencing (scRNA-seq) can be used to characterize variation in gene expression levels at high resolution. However, the sources of experimental noise in scRNA-seq are not yet well understood. We investigated the technical variation associated with sample processing using the single cell Fluidigm C1 platform. To do so, we processed three C1 replicates from three human induced pluripotent stem cell (iPSC) lines. We added unique molecular identifiers (UMIs) to all samples, to account for amplification bias. We found that the major source of variation in the gene expression data was driven by genotype, but we also observed substantial variation between the technical replicates. We observed that the conversion of reads to molecules using the UMIs was impacted by both biological and technical variation, indicating that UMI counts are not an unbiased estimator of gene expression levels. Based on our results, we suggest a framework for effective scRNA-seq studies.

scholarly journals Expression of SSEA4 and TRA1-60 as Marker of Induced Pluripotent Stem Cells by Small Molecule Compound VC6TFZ on Peripheral Blood Mononuclear Cell

2020 ◽  
Author(s):  
A Andrianto ◽  
Adityo Basworo ◽  
Ivana Purnama Dewi ◽  
Budi Susetio Pikir
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Small Molecule ◽  
Pluripotent Stem Cells ◽  
Mononuclear Cells ◽  
Control Group ◽  
Peripheral Blood Mononuclear ◽  
Induced Pluripotency ◽  
Small Molecule Compound ◽  
Induced Pluripotent

IntroductionIt is possible to induce pluripotent stem cells from somatic cells, offering an infinite cell resource with the potential for disease research and use in regenerative medicine. Due to ease of accessibility, minimum invasive treatment, and can be kept frozen, peripheral blood mononuclear cells (PBMC) were an attractive source cell. VC6TFZ, a small molecule compound, has been successfully reprogrammed from mouse fibroblast induced pluripotent stem cells (iPSCs). However, it has not been confirmed in humans.ObjectiveThe aim of this research is to determine whether the small molecule compound VC6TFZ can induced pluripotency of PBMC to generate iPSCs detected with expression of SSEA4 and TRA1-60.MethodsUsing the centrifugation gradient density process, mononuclear cells were separated from peripheral venous blood. Mononuclear cells were cultured for 6 days in the expansion medium. The cells were divided into four groups; group 1 (P1), which was not exposed to small molecules (control group) and groups 2-4 (P2-P4), the experimental groups, subjected to various dosages of the small molecule compound VC6TFZ (VPA, CHIR, Tranylcypromine, FSK, Dznep, and TTNPB). The induction of pluripotency using small molecule compound VC6TFZ was completed within 14 days, then for 7 days the medium shifted to 2i medium. iPSCs identification in based on colony morphology and pluripotent gene expression, SSEA4 and TRA1-60 marker, using immunocytochemistry.ResultsColonies appeared on reprogramming process in day 7th. These colonies had round, large, and cobble stone morphology like ESC. Gene expression of SSEA4 and TRA 1-60 increased statisticaly significant than control group (SSEA4 were P2 p=0.007; P3 p=0.001; P4 p=0.009 and TRA 1-60 were P2 p=0.002; P3 p=0.001; P4 p=0.001).ConclusionSmall molecule compound VC6TFZ could induced pluripotency of human PBMC to generate iPSCs. Pluripotxency marker gene expression, SSEA 4 and TRA 1-60, in the experimental group was statistically significantly higher than in the control group.

Sign in / Sign up

Export Citation Format

Share Document