Assistant Professor Nanyang Technological University, Singapore
Abstract: In the field of regenerative cardiology, stem cell therapy holds the potential for replacing damaged heart muscle. Through a patented differentiation method based on human recombinant laminins, we have previously demonstrated the reproducible generation of cardiovascular progenitors (CVPs) from human pluripotent stem cells. These CVPs showed strong engraftment, significant improvements in cardiac ejection fraction, and a 50% reduction in ventricular arrhythmias when transplanted intramyocardially into myocardial infarction (MI) models in mice and pigs. Immunosuppressive drugs were typically used during these studies to prevent immune rejection of the human grafts. However, the animals experienced side effects such as anemia and stomach ulcers. Therefore, to develop a safer cellular transplantation therapy, these challenges must be addressed. This project investigates the hypothesis that differentiating induced pluripotent stem cells (CLiPS) derived from cord lining epithelial cells into CVPs will enable the progenitors to maintain their hypo-immune state and persist in an immune-competent animal model without the need for systemic immunosuppression. Initially, we adapted pluripotent CLiPS cells and fibroblast-derived iPS cells from the Matrigel™ culture system to a xeno-free system using laminin-521 and chemically defined Nutristem cell culture media. We then characterized the cells by flow cytometry to assess pluripotent markers (Tra1-60 and Oct3/4) and karyotyping. Following this, the cells were differentiated into cardiac mesodermal lineage, and cardiac markers (Troponin-T (TNNT2) and a-actinin (ACTN2)) were quantified by flow cytometry and qPCR. Results showed that the newly adapted iPSCs maintained pluripotency and differentiation efficiency into cardiac lineage. Subsequently, luciferase-labeled CLiPS-CVP and control cells were transplanted into an immune-competent myocardial infarction mouse model for 4 weeks. Histological analysis and in vivo imaging were employed to monitor the cells’ engraftment, survival, and biodistribution of the cells within the host. These results could pave the way for hypo-immune cellular therapies for regenerative medicine, potentially overcoming the need for immunosuppression.
Funding Source: This work has been supported by grants from the National Research Foundation (CRP24-2020-0083), Singapore, and the Ministry of Education, Singapore (MOE-RS06/23, MOE-RG38/24, and MOE start-up grant, 022976-00001).
