Biology subjects

Heinson, Y. W.

Publications and source records attributed to Heinson, Y. W..

4 recordsLinked to original sources

bioRxiv2025

Response of human iPSC-cardiomyocytes to adrenergic drugs assessed by high-throughput pericellular oxygen measurements

Rate- and contractility-modulating drugs, such as adrenergic agonists and antagonists, are widely used in the treatment of cardiovascular conditions. Preclinical assessment of new modulators of rate, inotropy and metabolism can be aided by high-throughput (HT) methods for chronic measurements, coupled with scalable human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Here, we evaluate the utility of long-term optical (label-free) measurements of pericellular oxygen in a HT format (96-well plates) for the assessment of the effectiveness of adrenergic drugs in hiPSC-CMs. Quantitative oxygen consumption metrics were derived and correlated to measurements performed in the same samples using all-optical electrophysiology. Adrenergic agonists significantly increased oxygen consumption rate (OCR), best seen in the kinetics of initial depletion of pericellular oxygen, i.e. time to reach 5%. Adrenergic antagonists decreased OCR, best quantified using steady-state values for pericellular oxygen after at least 5 hours. OCR-based drug type identification correlated well with the acute spontaneous rate measurements in the same samples. Direct rate modulation with chronic optogenetic pacing sped up OCR in hiPSC-CMs. Blebbistatin, an excitation-contraction uncoupler, significantly reduced OCR. Computational modeling helped interpret our results by capturing the effects of pacing rate, adrenergic stimulation, and blebbistatin on oxygen consumption, thereby highlighting the key contribution of inotropy and mechanical contraction to OCR in hiPSC-CMs. We conclude that HT label-free optical oxygen measurements and the comprehensive in silico hiPSC-CM models, constrained by such measurements, represent valuable human-based approaches for non-invasive assessment of rate- and metabolism-modulating drugs in preclinical studies.

bioengineering↗

bioRxiv2024

Control of electromechanical waves in engineered tissue of human iPSC-cardiomyocytes using a Halbach array and magnetic nanoparticles

The Halbach array, originally developed for particle accelerators, is a compact arrangement of permanent magnets to create well-defined magnetic fields without heating. Here, we demonstrate its use for modulating the speed of electromechanical waves in cardiac syncytia of human stem cell-derived cardiomyocytes. At 40-50 mT magnetic field strength, a cylindrical dipolar Halbach array boosted the conduction velocity, CV, of excitation in a directional manner by up to 25% when the magnetic field was co-aligned with the electromechanical wave (but not when perpendicular to it). To observe the effects, a short-term incubation of the cardiac cell constructs with non-targeted magnetic nanoparticles, mNPs, was sufficient. This increased CV anisotropy, and the effects were most pronounced at slower pacing rates. Instantaneous formation and re-arrangement of elongated mNP clusters upon magnetic field rotation was seen, thus creating dynamic structural anisotropy that may have contributed to the directional CV effects. This approach may be useful for anti-arrhythmic control of cardiac waves. One sentence summaryA Halbach array of permanent magnets can modulate the speed of excitation waves in human cardiac cell assemblies with magnetic nanoparticles.

bioengineering↗

bioRxiv2023

Paradoxical anti-arrhythmic effects of Zim3, a CRISPRi effector, in human iPSC-cardiomyocytes

We show that Zim3, when used as Zim3-KRAB-dCas9 effector in interference CRISPR, without any guide RNAs, paradoxically upregulates key cardiac ion channel genes in human induced pluripotent stem-cell-derived cardiomyocytes, iPSC-CMs, responsible for healthy resting membrane potential, repolarization of the action potential and electrical transmission of signals. These were found to yield expected functional enhancements consistent with a more mature iPSC-CM phenotype, with potentially desirable properties.

molecular biology↗

bioRxiv2023

CRISPRi Gene Modulation and All-Optical Electrophysiology in Post-Differentiated Human iPSC-Cardiomyocytes

Uncovering gene-phenotype relationships can be enabled by precise gene modulation in human induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs) and follow up phenotyping using scalable all- optical electrophysiology platforms. Such efforts towards human functional genomics can be aided by recent CRISPR-derived technologies for reversible gene inhibition or activation (CRISPRi/a). We set out to characterize the performance of CRISPRi in post-differentiated iPSC-CMs, targeting key cardiac ion channel genes, KCNH2, KCNJ2, and GJA1, and providing a multiparametric quantification of the effects on cardiac repolarization, stability of the resting membrane potential and conduction properties using all- optical tools. More potent CRISPRi effectors, e.g. Zim3, and optimized viral delivery led to improved performance on par with the use of CRISPRi iPSC lines. Confirmed mild yet specific phenotype changes when CRISPRi is deployed in non-dividing differentiated heart cells is an important step towards more holistic pre-clinical cardiotoxicity testing and for future therapeutic use in vivo.

cell biology↗