Regenerating The External Layer Of The Heart

New research is revealing how to form epicardium cells from stem cells - enabling regeneration of the heart wall

Previous work in 2012 demonstrated that interfering with Wnt signalling (an important signalling molecule), was able to form myocardium - also known as heart muscle cells. Myocardium cells reside in the heart's muscular, middle layer and are largely responsible for pumping the blood throughout the body. They aren't the only important region of the heart however, and finding ways to make every heart cell type is equally critical to fully regenerating heart tissue. When the researchers experimented with further activation of the Wnt pathway, they discovered they could drive differentiation into epicardium cells too. 

"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"

Completing the list 

When the team analysed their newly formed epicardium cells further, they found they closely resembled 'natural' epicardium cells. More intriguingly, they found that applying an inhibitor to the Transforming Growth Factor Beta (TGF) pathway, they were able to sustain proliferation and grow more of these epicardium cells. The next step in their research is to form inner heart cell tissue; endocardium cell types. The ability to form all heart cell types could allow robust regeneration, and tailoring to an individual's specific heart damage - which may be in different areas. 

"The last piece is turning cardiac progenitor cells to endocardium cells (the heart's inner layer), and we are making progress on that. Heart attacks occur due to blockage of blood vessels. This blockage stops nutrients and oxygen from reaching the heart muscle, and muscle cells die. These muscle cells cannot regenerate themselves, so there is permanent damage, which can cause additional problems. These epicardium cells could be transplanted to the patient and potentially repair the damaged region"

Read more at MedicalXpress