scholarly journals Functional Impact of BeKm-1, a High-Affinity hERG Blocker, on Cardiomyocytes Derived from Human-Induced Pluripotent Stem Cells

2020 ◽  
Vol 21 (19) ◽  
pp. 7167
Author(s):  
Stephan De Waard ◽  
Jérôme Montnach ◽  
Barbara Ribeiro ◽  
Sébastien Nicolas ◽  
Virginie Forest ◽  
...  

IKr current, a major component of cardiac repolarization, is mediated by human Ether-à-go-go-Related Gene (hERG, Kv11.1) potassium channels. The blockage of these channels by pharmacological compounds is associated to drug-induced long QT syndrome (LQTS), which is a life-threatening disorder characterized by ventricular arrhythmias and defects in cardiac repolarization that can be illustrated using cardiomyocytes derived from human-induced pluripotent stem cells (hiPS-CMs). This study was meant to assess the modification in hiPS-CMs excitability and contractile properties by BeKm-1, a natural scorpion venom peptide that selectively interacts with the extracellular face of hERG, by opposition to reference compounds that act onto the intracellular face. Using an automated patch-clamp system, we compared the affinity of BeKm-1 for hERG channels with some reference compounds. We fully assessed its effects on the electrophysiological, calcium handling, and beating properties of hiPS-CMs. By delaying cardiomyocyte repolarization, the peptide induces early afterdepolarizations and reduces spontaneous action potentials, calcium transients, and contraction frequencies, therefore recapitulating several of the critical phenotype features associated with arrhythmic risk in drug-induced LQTS. BeKm-1 exemplifies an interesting reference compound in the integrated hiPS-CMs cell model for all drugs that may block the hERG channel from the outer face. Being a peptide that is easily modifiable, it will serve as an ideal molecular platform for the design of new hERG modulators displaying additional functionalities.

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Francesca Stillitano ◽  
Jens Hansen ◽  
Chi-Wing Kong ◽  
Ioannis Karakikes ◽  
Christian Funck-Brentano ◽  
...  

A large number of drugs can induce prolongation of cardiac repolarization and life-threatening cardiac arrhythmias. The prediction of this side effect is however challenging as it usually develops in some genetically predisposed individuals with normal cardiac repolarization at baseline. Here, we describe a platform based on a genetically diverse panel of induced pluripotent stem cells (iPSCs) that reproduces susceptibility to develop a cardiotoxic drug response. We generated iPSC-derived cardiomyocytes from patients presenting in vivo with extremely low or high changes in cardiac repolarization in response to a pharmacological challenge with sotalol. In vitro, the responses to sotalol were highly variable but strongly correlated to the inter-individual differences observed in vivo. Transcriptomic profiling identified dysregulation of genes (DLG2, KCNE4, PTRF, HTR2C, CAMKV) involved in downstream regulation of cardiac repolarization machinery as underlying high sensitivity to sotalol. Our findings offer novel insights for the development of iPSC-based screening assays for testing individual drug reactions.


2019 ◽  
Vol 11 (12) ◽  
pp. 1020-1044 ◽  
Author(s):  
Elena Genova ◽  
Federica Cavion ◽  
Marianna Lucafò ◽  
Luigina De Leo ◽  
Marco Pelin ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Chengyi Tu ◽  
Nathan J. Cunningham ◽  
Mao Zhang ◽  
Joseph C. Wu

Evaluation of potential vascular injury is an essential part of the safety study during pharmaceutical development. Vascular liability issues are important causes of drug termination during preclinical investigations. Currently, preclinical assessment of vascular toxicity primarily relies on the use of animal models. However, accumulating evidence indicates a significant discrepancy between animal toxicity and human toxicity, casting doubt on the clinical relevance of animal models for such safety studies. While the causes of this discrepancy are expected to be multifactorial, species differences are likely a key factor. Consequently, a human-based model is a desirable solution to this problem, which has been made possible by the advent of human induced pluripotent stem cells (iPSCs). In particular, recent advances in the field now allow the efficient generation of a variety of vascular cells (e.g., endothelial cells, smooth muscle cells, and pericytes) from iPSCs. Using these cells, different vascular models have been established, ranging from simple 2D cultures to highly sophisticated vascular organoids and microfluidic devices. Toxicity testing using these models can recapitulate key aspects of vascular pathology on molecular (e.g., secretion of proinflammatory cytokines), cellular (e.g., cell apoptosis), and in some cases, tissue (e.g., endothelium barrier dysfunction) levels. These encouraging data provide the rationale for continuing efforts in the exploration, optimization, and validation of the iPSC technology in vascular toxicology.


Tumor Biology ◽  
2020 ◽  
Vol 42 (9) ◽  
pp. 101042832096258
Author(s):  
Katsuhito Watanabe ◽  
Takashi Nakamura ◽  
Shoko Onodera ◽  
Akiko Saito ◽  
Takahiko Shibahara ◽  
...  

A missense mutation of the guanine nucleotide binding protein alpha stimulating activity polypeptide 1 ( GNAS) gene, typically Arg201Cys or Arg201His (R201H/R201C), leads to constitutive activation of the Gsα-cyclic AMP (cAMP) signaling pathway that causes several diseases. However, no germline mutations of GNAS have been identified to date, likely due to their lethality, and no robust human cell models have been generated. Therefore, the aim of this study was to generate GNAS-mutated disease-specific induced pluripotent stem cells as a model for these diseases. We then analyzed the functionality of this induced pluripotent stem cell model and differentiated epithelial cells. We generated disease-specific induced pluripotent stem cells by introducing a mutation in GNAS with the clustered regularly interspaced short palindromic repeats (CRISPR) nickase method, which has lower off-target effects than the conventional CRISPR/Cas9 method. We designed the target vector to contain the R201H mutation in GNAS, which was transfected into human control induced pluripotent stem cells (Nips-B2) by electroporation. We confirmed the establishment of GNASR201H -mutated ( GNASR201H/+) induced pluripotent stem cells that exhibited a pluripotent stem cell phenotype. We analyzed the effect of the mutation on cAMP production, and further generated teratomas for immunohistochemical analysis of the luminal epithelial structure. GNAS-mutated induced pluripotent stem cells showed significantly higher levels of intracellular cAMP, which remained elevated state for a long time upon hormonal stimulation with parathyroid hormone or adrenocorticotropic hormone. Immunohistochemical analysis revealed that several mucins, including MUC1, 2, and MUC5AC, are expressed in cytokeratin 18 (CK18)-positive epithelial cells. However, we found few CK18-positive cells in mutated induced pluripotent stem cell–derived teratoma tissues, and reduced MUCINs expression in mutated epithelial cells. There was no difference in CDX2 expression; however, mutated epithelial cells were positive for CEA and CA19-9 expression. GNASR201H-mutated induced pluripotent stem cells and GNASR201H-mutated epithelial cells have distinct phenotypic and differentiation characteristics. We successfully established GNASR201H-mutated human induced pluripotent stem cells with increased cAMP production. Considering the differentiation potential of induced pluripotent stem cells, these cells will be useful as a model for elucidating the pathological mechanisms of GNAS-mutated diseases.


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