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Updated: Dec 29, 2025
Generation, High-Throughput Screening, and Biobanking of Human-Induced Pluripotent Stem Cell-Derived Cardiac Spheroids
Published on: March 10, 2023
Cardioprotective effects of genetically engineered cardiac stem cells by spheroid formation on ischemic
Han Saem Jeong1, Chi-Yeon Park1, Jong-Ho Kim1
1Department of Cardiology, Cardiovascular Center, Korea University College of Medicine, Seoul, Republic of Korea.
Background:
Sca-1+ cardiac stem cells and their limited proliferative potential were major limiting factors for use in various studies.
Methods:
Therefore, the effects of sphere genetically engineered cardiac stem cells (S-GECS) inserted with telomerase reverse transcriptase (TERT) were investigated to examine cardiomyocyte survival under hypoxic conditions. GECS was obtained from hTERT-immortalized Sca-1+ cardiac stem cell (CSC) lines, and S-GECS were generated using poly-HEMA.
Results:
The optimal conditions for S-GECS was determined to be 1052 GECS cells/mm2 and a 48 h culture period to produce spheroids. Compared to adherent-GECS (A-GECS) and S-GECS showed significantly higher mRNA expression of SDF-1α and CXCR4. S-GECS conditioned medium (CM) significantly reduced the proportion of early and late apoptotic cardiomyoblasts during CoCl2-induced hypoxic injury; however, gene silencing via CXCR4 siRNA deteriorated the protective effects of S-GECS against hypoxic injury. As downstream pathways of SDF-1α/CXCR4, the Erk and Akt signaling pathways were stimulated in the presence of S-GECS CM. S-GECS transplantation into a rat acute myocardial infarction model improved cardiac function and reduced the fibrotic area. These cardioprotective effects were confirmed to be related with the SDF-1α/CXCR4 pathway.
Conclusions:
Our findings suggest that paracrine factors secreted from transplanted cells may protect host cardiomyoblasts in the infarcted myocardium, contributing to beneficial left ventricle (LV) remodeling after acute myocardial infarction (AMI).
Insights
Sphere genetically engineered cardiac stem cells (S-GECS) expressing telomerase reverse transcriptase (TERT) enhance cardiomyocyte survival and improve cardiac function after myocardial infarction by secreting protective paracrine factors via the SDF-1α/CXCR4 pathway.
Area of Science:
- Cardiovascular Biology
- Stem Cell Therapy
- Regenerative Medicine
Background:
- Sca-1+ cardiac stem cells have limited proliferative potential, hindering their therapeutic use.
- Genetic engineering and spheroid formation can overcome these limitations.
Purpose of the Study:
- To investigate the effects of sphere genetically engineered cardiac stem cells (S-GECS) with telomerase reverse transcriptase (TERT) on cardiomyocyte survival under hypoxic conditions.
- To elucidate the underlying mechanisms, including the SDF-1α/CXCR4 pathway.
Main Methods:
- Generated S-GECS from hTERT-immortalized Sca-1+ cardiac stem cell (CSC) lines using poly-HEMA.
- Optimized S-GECS culture conditions for spheroid formation.
- Assessed mRNA expression of SDF-1α and CXCR4, and the effects of S-GECS conditioned medium (CM) on cardiomyoblast apoptosis.
- Investigated downstream signaling pathways (Erk, Akt) and performed S-GECS transplantation in a rat acute myocardial infarction model.
Main Results:
- S-GECS exhibited significantly higher SDF-1α and CXCR4 expression compared to adherent GECS.
- S-GECS CM reduced cardiomyoblast apoptosis during hypoxic injury, an effect dependent on the SDF-1α/CXCR4 pathway.
- Transplantation of S-GECS improved cardiac function and reduced fibrosis in a rat AMI model, mediated by the SDF-1α/CXCR4 pathway.
Conclusions:
- S-GECS secrete paracrine factors that protect host cardiomyoblasts in infarcted myocardium.
- These factors contribute to beneficial left ventricle remodeling after acute myocardial infarction (AMI).
