A research team from the South Australian Health and Medical Research Institute (SAHMRI) has identified a previously unknown type of cell that could revolutionize tissue repair and regeneration in mammals.
These newly discovered cells, named EndoMac progenitors, have the remarkable capability to differentiate into two distinct types: endothelial cells, which create blood vessels, and macrophages, which are immune cells that play a crucial role in tissue repair and defense.
“These cells have an important job, to help grow blood vessels when the body calls for it,” Dr. Sanuri Liyange, a part of the research team, said.
“They are activated by injury or poor blood flow, at which point they rapidly expand to aid in healing.”
Proof of a century-old theory
For over a century, scientists have speculated about the existence of cells with functions similar to those of the newly discovered EndoMac progenitors, but they had never been identified—until now.
They were found in the outer layer of adult mice’s aortas and could potentially revolutionize treatments for conditions like diabetes, where the body’s natural healing processes are compromised.
Notably, EndoMac progenitors lack typical “self” markers, making them promising candidates for stem cell transplantation, as they are less likely to trigger an immune response.
Dr. Liyange and her team successfully isolated these cells from mice, cultivated them, and observed them forming colonies. Testing in diabetic mouse models showed dramatic improvements in wound healing, particularly in cases where healing would normally be impaired.
Understanding macrophages
To understand the significance of EndoMac progenitors, it’s essential to first examine macrophages. Macrophages are among the earliest immune cells produced during embryonic development and are crucial for tissue repair and defense.
In adults, most tissues retain macrophages made during early development, with these populations occasionally renewing to maintain immune defenses.
A century ago, scientists hypothesized that circulating stem cells in the blood could generate new macrophages throughout adulthood. For a long time, researchers believed these cells, which had been identified in mouse embryos, continued to exist into adulthood, originating from bone marrow.
However, recent studies suggest that bone marrow-derived stem cells are limited to a few tissues, such as the gut, skin, and heart.
Now, researchers propose that macrophages in adults are derived from previously undiscovered stem cells established early in life. This idea is still debated, but the new findings from Australia support this emerging theory.
The study suggests that embryonic progenitor cells responsible for producing macrophages are seeded in the heart’s aorta during early development, and as the mice mature, these progenitor cells introduce new macrophages into various tissues.
Further research
The research team is now extending their studies to explore EndoMac progenitor cells in skin and muscle tissue, with results anticipated within the next 12 months.
Additionally, they are investigating the presence of these cells in human tissue, and early indications are promising, potentially paving the way for breakthroughs in human tissue repair and regenerative medicine .
“We’re excited to continue exploring the potential of these cells. It’s early days, but the implications could be massive,” Dr. Liyanage said .
“This represents a significant advancement in our understanding of blood vessel regeneration and holds promise for creating more effective treatments that support the body’s capacity to heal and maintain function over time.”
The study has been published in the journal Nature Communications .
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