scholarly journals In vitro analyses of suspected arrhythmogenic thin filament variants as a cause of sudden cardiac death in infants

2019 ◽  
Vol 116 (14) ◽  
pp. 6969-6974 ◽  
Author(s):  
Sanam Shafaattalab ◽  
Alison Yueh Li ◽  
Eric Lin ◽  
Charles M. Stevens ◽  
Laura J. Dewar ◽  
...  
Keyword(s):  
Thin Filament ◽  
Troponin I ◽  
Induced Pluripotent Stem Cell ◽  
Biophysical Properties ◽  
Unexpected Death ◽  
Thin Filaments ◽  
Sarcomeric Mutations ◽  
Induced Pluripotent ◽  
Dynamics Simulations

Sudden unexpected death of an infant (SUDI) is a devastating occurrence for families. To investigate the genetic pathogenesis of SUDI, we sequenced >70 genes from 191 autopsy-negative SUDI victims. Ten infants sharing a previously unknown variant in troponin I (TnI) were identified. The mutation (TNNI1R37C+/−) is in the fetal/neonatal paralog of TnI, a gene thought to be expressed in the heart up to the first 24 months of life. Using phylogenetic analysis and molecular dynamics simulations, it was determined that arginine at residue 37 inTNNI1may play a critical functional role, suggesting that the variant may be pathogenic. We investigated the biophysical properties of theTNNI1R37C mutation in human reconstituted thin filaments (RTFs) using fluorometry. RTFs reconstituted with the mutant R37C TnI exhibited reduced Ca2+-binding sensitivity due to an increased Ca2+off-rate constant. Furthermore, we generatedTNNI1R37C+/−mutants in human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) using CRISPR-Cas9. In monolayers of hiPSC-CMs, we simultaneously monitored voltage and Ca2+transients through optical mapping and compared them to their isogenic controls. We observed normal intrinsic beating patterns under control conditions inTNNI1R37C+/−at stimulation frequencies of 55 beats/min (bpm), but these cells showed no restitution with increased stimulation frequency to 65 bpm and exhibited alternans at >75 bpm. The WT hiPSC-CMs did not exhibit any sign of arrhythmogenicity even at stimulation frequencies of 120 bpm. The approach used in this study provides critical physiological and mechanistic bases to investigate sarcomeric mutations in the pathogenesis of SUDI.

Use of 3D culture systems to generate human induced pluripotent stem cell-derived [beta]-cells in vitro

2018 ◽  
Author(s):  
Fantuzzi Federica ◽  
Toivonen Sanna ◽  
Schiavo Andrea Alex ◽  
Pachera Nathalie ◽  
Rajaei Bahareh ◽  
...  
Keyword(s):  
Stem Cell ◽  
Beta Cells ◽  
Pluripotent Stem Cell ◽  
3D Culture ◽  
Induced Pluripotent Stem Cell ◽  
Culture Systems ◽  
Induced Pluripotent

scholarly journals Bestrophinopathies: perspectives on clinical disease, Bestrophin-1 function and developing therapies

2021 ◽  
Vol 13 ◽  
pp. 251584142199719
Author(s):  
Simranjeet Singh Grewal ◽  
Joseph J. Smith ◽  
Amanda-Jayne F. Carr
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Induced Pluripotent Stem Cell ◽  
Underlying Disease ◽  
Incomplete Penetrance ◽  
Inherited Retinal Dystrophies ◽  
Retinal Dystrophies ◽  
High Acuity ◽  
Induced Pluripotent

Bestrophinopathies are a group of clinically distinct inherited retinal dystrophies that typically affect the macular region, an area synonymous with central high acuity vision. This spectrum of disorders is caused by mutations in bestrophin1 ( BEST1), a protein thought to act as a Ca2+-activated Cl- channel in the retinal pigment epithelium (RPE) of the eye. Although bestrophinopathies are rare, over 250 individual pathological mutations have been identified in the BEST1 gene, with many reported to have various clinical expressivity and incomplete penetrance. With no current clinical treatments available for patients with bestrophinopathies, understanding the role of BEST1 in cells and the pathological pathways underlying disease has become a priority. Induced pluripotent stem cell (iPSC) technology is helping to uncover disease mechanisms and develop treatments for RPE diseases, like bestrophinopathies. Here, we provide a comprehensive review of the pathophysiology of bestrophinopathies and highlight how patient-derived iPSC-RPE are being used to test new genomic therapies in vitro.

In vitro pharmacologic testing using human induced pluripotent stem cell-derived cardiomyocytes

2009 ◽  
Vol 385 (4) ◽  
pp. 497-502 ◽  
Author(s):  
Tomofumi Tanaka ◽  
Shugo Tohyama ◽  
Mitsushige Murata ◽  
Fumimasa Nomura ◽  
Tomoyuki Kaneko ◽  
...  
Keyword(s):  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Induced Pluripotent

scholarly journals Persistence of intramyocardially transplanted murine induced pluripotent stem cell-derived cardiomyocytes from different developmental stages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gabriel Peinkofer ◽  
Martina Maass ◽  
Kurt Pfannkuche ◽  
Agapios Sachinidis ◽  
Stephan Baldus ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Stem Cell ◽  
Cell Adhesion ◽  
Developmental Stage ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Induced Pluripotent

Abstract Background Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) are regarded as promising cell type for cardiac cell replacement therapy, but it is not known whether the developmental stage influences their persistence and functional integration in the host tissue, which are crucial for a long-term therapeutic benefit. To investigate this, we first tested the cell adhesion capability of murine iPSC-CM in vitro at three different time points during the differentiation process and then examined cell persistence and quality of electrical integration in the infarcted myocardium in vivo. Methods To test cell adhesion capabilities in vitro, iPSC-CM were seeded on fibronectin-coated cell culture dishes and decellularized ventricular extracellular matrix (ECM) scaffolds. After fixed periods of time, stably attached cells were quantified. For in vivo experiments, murine iPSC-CM expressing enhanced green fluorescent protein was injected into infarcted hearts of adult mice. After 6–7 days, viable ventricular tissue slices were prepared to enable action potential (AP) recordings in transplanted iPSC-CM and surrounding host cardiomyocytes. Afterwards, slices were lysed, and genomic DNA was prepared, which was then used for quantitative real-time PCR to evaluate grafted iPSC-CM count. Results The in vitro results indicated differences in cell adhesion capabilities between day 14, day 16, and day 18 iPSC-CM with day 14 iPSC-CM showing the largest number of attached cells on ECM scaffolds. After intramyocardial injection, day 14 iPSC-CM showed a significant higher cell count compared to day 16 iPSC-CM. AP measurements revealed no significant difference in the quality of electrical integration and only minor differences in AP properties between d14 and d16 iPSC-CM. Conclusion The results of the present study demonstrate that the developmental stage at the time of transplantation is crucial for the persistence of transplanted iPSC-CM. iPSC-CM at day 14 of differentiation showed the highest persistence after transplantation in vivo, which may be explained by a higher capability to adhere to the extracellular matrix.

scholarly journals Disease Modeling and Disease Gene Discovery in Cardiomyopathies: A Molecular Study of Induced Pluripotent Stem Cell Generated Cardiomyocytes

2021 ◽  
Vol 22 (7) ◽  
pp. 3311
Author(s):  
Satish Kumar ◽  
Joanne E. Curran ◽  
Kashish Kumar ◽  
Erica DeLeon ◽  
Ana C. Leandro ◽  
...  
Keyword(s):  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Disease Gene ◽  
Disease Modeling ◽  
Gene Discovery ◽  
Induced Pluripotent Stem Cell ◽  
P Value ◽  
Disease Gene Discovery ◽  
Induced Pluripotent

The in vitro modeling of cardiac development and cardiomyopathies in human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs) provides opportunities to aid the discovery of genetic, molecular, and developmental changes that are causal to, or influence, cardiomyopathies and related diseases. To better understand the functional and disease modeling potential of iPSC-differentiated CMs and to provide a proof of principle for large, epidemiological-scale disease gene discovery approaches into cardiomyopathies, well-characterized CMs, generated from validated iPSCs of 12 individuals who belong to four sibships, and one of whom reported a major adverse cardiac event (MACE), were analyzed by genome-wide mRNA sequencing. The generated CMs expressed CM-specific genes and were highly concordant in their total expressed transcriptome across the 12 samples (correlation coefficient at 95% CI =0.92 ± 0.02). The functional annotation and enrichment analysis of the 2116 genes that were significantly upregulated in CMs suggest that generated CMs have a transcriptomic and functional profile of immature atrial-like CMs; however, the CMs-upregulated transcriptome also showed high overlap and significant enrichment in primary cardiomyocyte (p-value = 4.36 × 10−9), primary heart tissue (p-value = 1.37 × 10−41) and cardiomyopathy (p-value = 1.13 × 10−21) associated gene sets. Modeling the effect of MACE in the generated CMs-upregulated transcriptome identified gene expression phenotypes consistent with the predisposition of the MACE-affected sibship to arrhythmia, prothrombotic, and atherosclerosis risk.

scholarly journals Real-Time Intraoperative MRI Intracerebral Delivery of Induced Pluripotent Stem Cell-Derived Neurons

2017 ◽  
Vol 26 (4) ◽  
pp. 613-624 ◽  
Author(s):  
Scott C. Vermilyea ◽  
Jianfeng Lu ◽  
Miles Olsen ◽  
Scott Guthrie ◽  
Yunlong Tao ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Survival ◽  
Real Time ◽  
Pluripotent Stem Cell ◽  
Viral Vector ◽  
Induced Pluripotent Stem Cell ◽  
Cell Delivery ◽  
Intracerebral Injection ◽  
Induced Pluripotent

Induced pluripotent stem cell (iPSC)-derived neurons represent an opportunity for cell replacement strategies for neurodegenerative disorders such as Parkinson's disease (PD). Improvement in cell graft targeting, distribution, and density can be key for disease modification. We have previously developed a trajectory guide system for real-time intraoperative magnetic resonance imaging (RT-IMRI) delivery of infusates, such as viral vector suspensions for gene therapy strategies. Intracerebral delivery of iPSC-derived neurons presents different challenges than viral vectors, including limited cell survival if cells are kept at room temperature for prolonged periods of time, precipitation and aggregation of cells in the cannula, and obstruction during injection, which must be solved for successful application of this delivery approach. To develop procedures suitable for RT-IMRI cell delivery, we first performed in vitro studies to tailor the delivery hardware (e.g., cannula) and defined a range of parameters to be applied (e.g., maximal time span allowable between cell loading in the system and intracerebral injection) to ensure cell survival. Then we performed an in vivo study to evaluate the feasibility of applying the system to nonhuman primates. Our results demonstrate that the RT-IMRI delivery system provides valuable guidance, monitoring, and visualization during intracerebral cell delivery that are compatible with cell survival.

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