External Layer Of Human Heart Successfully Regenerated Using Stem Cells
Researchers have developed a process to regenerate the cells around the external surface of the human heart, called epicardium cells. The results of this research bring medicine closer to the moment when a complete regeneration of an entire heart wall will be possible.
The study, published in the journal Nature Biomedical Engineering, describes the methodological assessment of this operation.
Heart Attack Treatment, Soon Possible Through Stem Cells
Myocardium is the muscular tissue of the heart displayed as a layer of the walls. Its main function is to offer scaffolding for the chambers of the heart, it also acts as an assistant in the contraction and relaxation of the heart walls, allowing blood circulation from a chamber to another, as well as electrostimulation from its tissues to the epicardium.
The Wnt signaling pathways are a group of transduction pathways consisting of proteins which give signals to the cells through the cell surface receptors. Three Wnt signaling pathways have been classified in the literature: the canonical Wnt pathway, the noncanonical planar cell polarity pathway, and the noncanonical Wnt/ calcium pathway.
Back in 2012, the team discovered that treating the human stem cells with chemicals which activate and inhibit the Wnt pathway, they turn into myocardium muscle cells.
"We needed to provide the cardiac progenitor cells with additional information in order for them to generate into epicardium cells, but prior to this study, we didn't know what that information was. Now, we know that if we activate the cells' Wnt signaling pathway again, we can re-drive these cardiac progenitor cells to become epicardium cells, instead of myocardium cells," noted said Xiaojun Lance Lian, assistant professor of biomedical engineering and biology, who is leading the study at Penn State.
The method employed by the researchers in generating epicardium cells could be extrapolated to clinical applications, and used for treating individuals who have suffered from heart attack. The mechanism of a heart attack lies in the blockage of blood vessels, which doesn't allow oxygen and nutrients to get to the heart muscle, which causes the affected muscles to die.
"Understanding the molecular mechanisms that control the specification and self-renewal of epicardial lineages from naive progenitor cells is of fundamental importance to elucidate the regulatory mechanisms underlying both human heart development and cardiovascular diseases," noted the research.
In the aftermath of a heart attack, it's impossible for the heart muscle cells to regenerate, hence the permanent damage that this condition leaves the patients with. However, according to the data brought by this new research, the epicardium cells can be transplanted to the patient, which would give the patients the possibility to have their affected muscle repaired.
"In summary, our findings support a model of human epicardial development in which small-molecule-mediated exogenous modulation of Wnt/β-catenin signaling is sufficient for the specification of epicardial cells from hPSCs," added the research.
Heart Attack, A Lead Cause Of Death
Yearly, approximately 735,000 Americans suffer from a heart attack, 525,000 of whom are a first heart attack, while 210,000 occur in individuals who have already suffered a heart attack.