Abstract 12622: The Modeling of Werner Syndrome by Induced Pluripotent Stem Cells

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Gakuto Yozu ◽  
Shinsuke Yuasa ◽  
Chikaaki Motoda ◽  
Dai Kusumoto ◽  
Akira Kunitomi ◽  
...  

Backgrounds: Werner syndrome (WS) is a rare autosomal recessive disorder characterized by premature onset of several aging-associated diseases, such as atherosclerosis, diabetes, cancer, and early death. The aging phenotypes of WS is resembling to those of normal aging. To uncover the mechanism of aging, we tried to model WS by patient-specific induced pluripotent stem cells (iPSCs). WS is caused by mutations in WRN gene belonging to the RecQ DNA helicase family which plays a role in genomic stability. But some of WS phenotypes are hardly explained by genomic instability. Thus, we aimed to model WS by patient-specific iPSCs to elucidate the mechanisms. Methods and Results: We sampled T lymphocytes from a patient with WS. Then we transduced with Yamanaka factors (OCT4, SOX2, KLF4, and MYC) by sendai virus, and iPSC colonies were derived. We confirmed that WS-iPSCs expressed pluripotent markers, could differentiate into all three germ-layer derived tissues, and retained a normal karyotype. We could culture WS-iPSCs over 2 years with pluripotent status. Then, we differentiated WS-iPSCs into fibroblasts-like cells. The proliferation rate of WS-iPSC-derived fibroblast-like cells (WS-iPSC-fibroblasts) was significantly decreased. WS-iPSC-fibroblasts showed a vulnerability to cellular stress and resulted in increased cell population which is positive for senescence associated β-galactosidase activity and γ-H2AX foci. Singled WS-iPSC-fibroblasts showed excessive blebbing of plasma membrane and increased apoptosis compared with control-iPSC-fibroblasts. To compare global gene expression profiles, we performed microarray analysis in WS-iPSC-fibroblasts and control-iPSC-fibroblasts. Interestingly, WS-iPSC-fibroblasts reproduced the global gene expression pattern of physiological aging. To confirm whether the phenotypes of WS-iPSCs are induced by WRN mutation, we generated isogenic control of WS-iPSC (corrected-WS-iPSC) by homologous recombination using helper-dependent adenovirus vector. Corrected-WS-iPSCs lost the aging-associated phenotypes but showed the phenotypes resembling to control-iPSCs. Conclusion: We modeled aging phenotypes by WS-specific iPSCs. This model would be utilize for uncovering the aging mechanisms.

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S234-S234
Author(s):  
Lorna Farrelly ◽  
Shuangping Zhang ◽  
Erin Flaherty ◽  
Aaron Topol ◽  
Nadine Schrode ◽  
...  

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.


2021 ◽  
Vol 7 (12) ◽  
pp. eabf7412
Author(s):  
P. Nayak ◽  
A. Colas ◽  
M. Mercola ◽  
S. Varghese ◽  
S. Subramaniam

Understanding the mechanisms of myogenesis in human induced pluripotent stem cells (hiPSCs) is a prerequisite to achieving patient-specific therapy for diseases of skeletal muscle. hiPSCs of different origin show distinctive kinetics and ability to differentiate into myocytes. To address the unique cellular and temporal context of hiPSC differentiation, we perform a longitudinal comparison of the transcriptomic profiles of three hiPSC lines that display differential myogenic specification, one robust and two blunted. We detail temporal differences in mechanisms that lead to robust myogenic specification. We show gene expression signatures of putative cell subpopulations and extracellular matrix components that may support myogenesis. Furthermore, we show that targeted knockdown of ZIC3 at the outset of differentiation leads to improved myogenic specification in blunted hiPSC lines. Our study suggests that β-catenin transcriptional cofactors mediate cross-talk between multiple cellular processes and exogenous cues to facilitate specification of hiPSCs to mesoderm lineage, leading to robust myogenesis.


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