Individual cells within the same heart cope differently with high blood pressure, according to a study in human cells and mice published today in Nature Communications.
"These results are the first to show that some cells fail and others adapt to high blood pressure within the same heart,” says first author Seitaro Nomura of the University of Tokyo. “I am very interested in the increased activity of genes that are important for making energy in the cell.”
According to the World Health Organization, cardiovascular diseases are the number one cause of death worldwide. High blood pressure causes heart failure, but the underlying mechanism by which this occurs is unknown.
In this new study, cells that adapted to high blood pressure were found to be thicker overall than healthy cells. These thicker cells demanded more energy but were able to keep the heart beating, and cells that did not adapt became stretched out and weak, like a worn-out elastic band.
Using a technique called single-cell transcriptome analysis, Nomura and other researchers examined the gene activity of hundreds of individual cells from mice and human heart-surgery patients. In this case, the single-cell technique is preferable to averaging the gene activity of many cells because it can reveal differences between individual cells from the same heart.
The scientists identified multiple groups of genes with different activity depending on whether or not they adapted to high blood pressure, but they focused on one gene called p53. Cancer researchers will recognize this gene as being important for responding to cell damage and maintaining cell growth and division. In this study, p53 showed increased activity in failing cells.
"Scientists already know how to reprogram adult cells into induced pluripotent stem (iPS) cells," said Nomura. "This gives me confidence that, eventually, we may find a way to reprogram failing heart cells into adaptive heart cells.”
Cardiologists of the future may be able to coax cells to adapt to the high pressure of hypertension, a narrow aorta, or heart attack in order to prevent heart failure.
Image: University of Tokyo researchers used human cells and mice to study the genetic differences between heart muscle cells that adapt and those that fail when subjected to high blood pressure. The research has potential future applications in treatment of cardiovascular disease. Image courtesy of the University of Tokyo.