Looking to the Future: Preliminary Data on Cardioids Generated from Human Cardiac Adipose Tissue

Background: Cardiovascular diseases (CVD) remain the leading cause of death worldwide, claiming 17.9 million lives annually. A deeper understanding of these diseases is crucial. Current cell biology research faces limitations, and findings from animal models do not always translate directly to humans, highlighting the need for new research models. Organoid research has advanced with the discovery of induced pluripotent stem cells (iPSCs), though iPSCs carry risks of unintended cellular effects. Using stem cells derived from adult tissue can reduce these risks and enable the collection of large quantities from small biopsies. Our goal is to generate cardioids from cardiac adipose tissue to provide a novel and relevant model for cardiovascular research.

Methods: Cardiac fat tissue from patients at the University Hospital of Düsseldorf’s cardiac surgery department is isolated, and the stromal vascular fraction (SVF) is obtained. After two-dimensional cultivation, SVF spheroids are generated using ultra-low attachment plates. Mesodermal differentiation is induced by activating the Wnt signaling pathway. In the second step, inhibition of the Wnt signaling pathway directs differentiation toward the cardiac lineage. The final step involves cardiac specification. Since vascular endothelial growth factor-A (VEGF-A) appears to be an essential factor, the presence of endothelial cells (ECs) was examined and characterized, along with other heart-related cell types, using immunofluorescence.

Results: After differentiation, the spheroids exhibited an α-actinin positive signal. In a high-throughput experimental setup, over 100 conditions were tested, and a cardiac troponin T (cTNT) positive signal was detected in three protocols. These protocols were repeated, and the cTNT-positive signal was confirmed. Additionally, the cTNT-positive spheroids also showed a CD31 positive signal.

Conclusion: Of the protocols tested, 85 showed an actinin-positive signal, but only three of these protocols were able to generate cTNT-positive cells, other unidentified α-actinin-positive cells, and ECs. The presence of at least these three cell types is the first step required to define a cardioid. This is the first step in generating cardiac cells in a 3D cell culture model derived from human adipose tissue. Further validation of the protocol and confirmation of its reproducibility are still pending. These initial results suggest the development of a valuable tool that could facilitate personalized medicine for the treatment of CVD in the future.

Publication History

Article published online:
11 February 2025