Researchers grow human blood vessels in mice from adult progenitor cells

Jul 19, 2008

For the first time, researchers have successfully grown functional human blood vessels in mice using cells from adult human donors — an important step in developing clinical strategies to grow tissue, researchers report in Circulation Research: Journal of the American Heart Association.

"What's really significant about our study is that we are using human cells that can be obtained from blood or bone marrow rather than removing and using fully developed blood vessels," said Joyce Bischoff, Ph.D., senior author of the study and associate professor at Harvard Medical School and Children's Hospital Boston.

The researchers combined two different types of progenitor cells in a culture dish of nutrients and growth factors, then washed off the nutrients and implanted the cells into mice with weakened immune systems. Once implanted, the progenitor cell mixture grew and differentiated into a small ball of healthy blood vessels.

Progenitor cells are similar to stem cells but can only differentiate into specific cells, while stem cells can differentiate into practically any cell in the body.

In the study, researchers used two different kinds of progenitor cells to grow blood vessels: the endothelial progenitor cells (EPCs), which become cells that line the vessels, and mesenchymal progenitor cells (MPCs), which differentiate into the cells that surround the lining and provide stability.

The researchers used different combinations of the two types of progenitor cells. They found that a mixture of adult blood- and adult bone marrow-derived progenitor cells or a combination of umbilical cord blood-derived and adult bone marrow-derived cells resulted in the greatest density of new blood vessel formation.

The ability to rapidly grow two-layered blood vessels without using embryonic or umbilical cord blood stem cells could skirt many ethical concerns, Bischoff said. It would also solve a persistent problem in treating several medical conditions that result from ischemia — the inability of oxygen-rich blood to reach an organ or tissue — such as heart attacks, wound healing and many acute injuries.

"What we are most interested in right now is speeding up the vascularization (the formation of blood vessels)," Bischoff said. "We see very good and extensive vasculature in seven days and we'd like to see that in 24 or 48 hours. If you have an ischemic tissue, it's dying tissue, so the faster you can establish blood flow the better."

If researchers can develop ways to speed the growth of the vessels, non-surgical cardiac bypass procedures could potentially grow new vessels around those blocked by atherosclerosis.

Bischoff said other findings include:

-- The cells created a vigorous network of vessels that connected to one another and to the vessels of the host mouse within seven days and continued to transport blood during the four-week study.

-- Once combined and implanted, the two progenitor cells arranged themselves into vessels with minimal outside help, i.e., without any genetic alteration or manipulation to improve their growth. This is important because many growth-promoting genes are the same genes that become activated in cancer.

-- Mixtures of EPCs and MPCs from adult donors were as effective at generating vessels as those made from a mixture of cord blood EPCs and adult bone marrow MPCs. That finding increases the likelihood of someday being able to easily find clinically useful amounts of progenitor cells.

The research could also enhance tissue engineering — growing new organs for later implantation into patients, another medical research field that needs good sources of microvascularization to develop, Bischoff said.

Source: American Heart Association

Explore further: The impact of bacteria in our guts

add to favorites email to friend print save as pdf

Related Stories

Biology made simpler with "clear" tissues

Aug 04, 2014

(Phys.org) —In general, our knowledge of biology—and much of science in general—is limited by our ability to actually see things. Researchers who study developmental problems and disease, in particular, ...

Designing exascale computers

Jul 23, 2014

"Imagine a heart surgeon operating to repair a blocked coronary artery. Someday soon, the surgeon might run a detailed computer simulation of blood flowing through the patient's arteries, showing how millions ...

How honey bees stay cool

Jul 23, 2014

Honey bees, especially the young, are highly sensitive to temperature and to protect developing bees, adults work together to maintain temperatures within a narrow range. Recently published research led by ...

The heart of an astronaut, five years on

Jul 22, 2014

The heart of an astronaut is a much-studied thing. Scientists have analyzed its blood flow, rhythms, atrophy and, through journal studies, even matters of the heart. But for the first time, researchers are ...

Recommended for you

The impact of bacteria in our guts

10 hours ago

The word metabolism gets tossed around a lot, but it means much more than whether you can go back to the buffet for seconds without worrying about your waistline. In fact, metabolism is the set of biochemical ...

Stem cell therapies hold promise, but obstacles remain

10 hours ago

(Medical Xpress)—In an article appearing online today in the journal Science, a group of researchers, including University of Rochester neurologist Steve Goldman, M.D., Ph.D., review the potential and ch ...

New hope in fight against muscular dystrophy

11 hours ago

Research at Stockholm's KTH Royal Institute of Technology offers hope to those who suffer from Duchenne muscular dystrophy, an incurable, debilitating disease that cuts young lives short.

Biologists reprogram skin cells to mimic rare disease

Aug 21, 2014

Johns Hopkins stem cell biologists have found a way to reprogram a patient's skin cells into cells that mimic and display many biological features of a rare genetic disorder called familial dysautonomia. ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

E_L_Earnhardt
not rated yet Jul 20, 2008
Now learn to control angiogenesis