Stem cell researchers at the University of British Columbia (UBC) have successfully managed to grow human blood vessels in the lab. The finding could mark a giant leap forward in the fight against vascular diseases such as Alzheimer's, cancer, and diabetes by allowing risk-free experimentation on live human tissue.

Human embryonic stem cells are typically derived from eggs which have been expressly donated for scientific research. The eggs are artificially fertilized and then allowed to develop into a primitive embryo over the following four to five days, at which point the cells are harvested. While the ethical considerations around this practice are complex, the study of stem cells has a truly exciting potential for the advancement of modern medicine, with applications ranging from tissue regeneration in bones and lungs to the production of unlimited supplies of transfusion blood.

In their latest study, UBC researchers led by Dr. Josef Penninger have harnessed stem cells once more to grow the organoids (miniaturized precursors) of human blood vessels.

The organoids were implanted in mice, where they initially survived at a rate of over 95 percent. Astonishingly, over a six-month period, the cells developed into structures that strongly resemble human blood vessels – including arteries and capillaries – down to the molecular level.

"Being able to build human blood vessels as organoids from stem cells is a game-changer," said Penninger. "This could potentially allow researchers to unravel the causes and treatments for a variety of vascular diseases, from Alzheimer's disease, cardiovascular diseases, wound healing problems, stroke, cancer and, of course, diabetes."

Diabetes is estimated to affect 420 million people worldwide, and one of its symptoms is a still-unexplained enlargement of the membrane which surrounds the blood vessels. The deformation impairs the delivery of oxygen and nutrients to cells and tissues, increasing the risk of heart attacks, blindness, and kidney failure.

Penninger and team were able to use their technique to study the deterioration of diabetic blood vessels on live, lab-grown human tissue.

The researchers found that none of the current anti-diabetic medications had positive effects on these blood vessel defects, but, through trial and error, they discovered an enzyme inhibitor that prevented the thickening of blood vessel walls, suggesting a possible avenue of treatment.

The study is further detailed in the latest edition of the scientific journal Nature.

Source: UBC

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