Abstract 4370209: PROLONGED PROLIFERATION OF EARLY-STAGE HUMAN PLURIPOTENT STEM CELL-DERIVED VENTRICULAR CARDIOMYOCYTES REDUCES PACEMAKING FUNCTION WHILE PROMOTING MATURATION
Bibliographic record
Abstract
Introduction: Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) hold great promise for cell therapy and drug discovery. However, their inherent immaturity, characterized by spontaneous beating, limits their utility. Interestingly, previous data showed that proliferating hPSC-CMs exhibited a slower beat rate, but their genetic and maturation status was not reported. Here, we show that prolonged proliferation of hPSC-derived ventricular cardiomyocytes (hPSC-VCMs) reduces beat rate and pacemaker gene expression along with the increased expression of genes associated with cardiomyocyte maturation. Hypothesis: Prolonged proliferation of early-stage hPSC-VCMs leads to a reduction in beat rate and pacemaker gene expression and improves maturation. Methods: Four hPSC lines were differentiated to early-stage hPSC-VCMs. On day 11 of differentiation, early-stage hPSC-VCMs were harvested, replated, and proliferated weekly for 5 weeks alongside time-matched, non-proliferated control hPSC-VCMs. Protein expression, gene expression, and electrophysiological activity were evaluated using flow cytometry, RNA sequencing, and microelectrode array analysis, respectively. Data are shown as mean ± SEM. Results: After 5 weeks, the cardiomyocyte marker cTnT increased from 88 ± 4% (day 11, n = 15) to 94 ± 3% (n = 15) in proliferated hPCS-VCMs, which was higher than the non-proliferated control (60 ± 7%, n = 15), and resulted in an ~80-fold cell expansion. Proliferated hPSC-VCMs exhibited a stepwise decrease in beat rate over five passages (P1 = 28 ± 1 BPM, P2 = 16 ± 1 BPM, P3 = 11 ± 1 BPM, P4 = 8 ± 3 BPM, P5 = 10 ± 1 BPM; n = 4), a trend not observed in control hPSC-VCMs (P1 = 23 ± 2 BPM, P2 = 29 ± 3 BPM, P3 = 33 ± 6 BPM, P4 = 20 ± 4 BPM, P5 = 37 ± 1 BPM; n = 4). Passages 2, 3, and 5 had significantly lower beat rates compared to their time-matched controls (p < 0.05). RNA sequencing revealed a corresponding stepwise downregulation of pacemaker genes ( HCN1 , HCN4 , CACNA1H ) and upregulation of maturation-related genes ( MYL2 , KCNH2 , CACNA1C , SCN5A , KCNJ2 , JPH2 ) in proliferated cells. Notably, expression of cardiac ion channel genes KCNH2 , KCNQ1 , and CACNA1C in proliferated hPSC-VCMs were comparable to those found in the adult human ventricle. Conclusion: Prolonged proliferation of hPSC-VCMs effectively reduces intrinsic pacemaking activity and promotes a mature phenotype which will improve their utility in basic and translational cardiovascular research.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".