Historically, scientists have studied how cells develop and give rise to specialized cells, such as heart, liver, or skin cells, by examining specific proteins. However, it remains unclear how many of these proteins influence the activity of hundreds of genes at the same time to turn one cell type into another cell type. For example, as the heart develops, stem cells and other specialized cells will give rise to heart muscle cells, endothelial cells (lining of blood vessels), smooth muscle cells, and cardiac fibroblasts. But the details of this process remain mysterious.
As a result of a $6 million, seven-year grant from the National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH), researchers from the Perelman School of Medicine at the University of Pennsylvania are launching new efforts to uncover how the development and maintenance of heart cells is influenced by DNA. These insights could help drive future research on new therapies for cardiac disease.
Penn Medicine researchers propose that nuclear architecture, which governs the availability of hundreds of genes within a cell, plays a critical role in achieving the proper identity of a cell. Specifically, they plan to study how the packaging and organization of DNA in 3D-;meaning understanding how DNA folds and twists in a complex way to fit into the tiny space of a cell nucleus-;impacts cell development. The work is supported by their previous research, which shows that nuclear architecture governs cardiac cellular identity during both development and disease.
This research has the potential to significantly advance our understanding of how cardiac cells arise and keep their identity for a lifetime. By viewing congenital heart disease and other cardiac diseases through the lens of how DNA is organized in the cell, many therapeutic opportunities that have remained untapped may come to light."
Rajan Jain, MD, Principal Investigator, Assistant Professor of Medicine and Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania
The way the nucleus is organized inside cells plays a crucial role in controlling the genes that determine cell identity. The nucleus acts like the command center of the cell, controlling what genes are accessible or available for use.
The Jain lab's work suggests that the way the DNA is folded and arranged within the nucleus can determine which genes are accessible and active, influencing the cell's identity. The way the DNA is folded and organized can be compared to a complex origami structure, where each fold and crease determines the final shape and function. The research aims to unravel the role of genome folding in controlling cell behavior, particularly in heart cells, and to identify key processes involved in this regulation. Researchers will also explore how the spatial positioning of DNA affects gene activity during the development of heart cells. By studying this process, researchers can examine how the identity of heart cells is maintained. This process is important for our overall health; incorrect development of heart cells or altering its identity could contribute to congenital heart disease or cardiomyopathy.
"As I trained it was always assumed that therapies can't target specific proteins in the nucleus, but that has changed over the last few years," Jain said. "Leveraging those advancements and past work as an inspiration, I hope this research will eventually allow us to design new medicines that will directly target how DNA is organized."
This research is supported by the National Heart, Lung, and Blood Institute of the NIH (R35HL166663).