- Scientists grow perfect vascular organoids that mimic the function and structure of real human blood vessels.
- The discovery could help scientists establish the underlying causes of various vascular diseases, including diabetes, cancer and Alzheimer’s disease.
Blood vessels are essential tissue for carrying nutrients and oxygen, processing waste and carbon dioxide, and regulating body temperature. In order to maintain about 60 trillion cells, blood vessels are spread out all over our bodies.
And since each organ in the human body is connected to the circulatory system (a network containing blood, blood vessels, and the heart), it could potentially enable scientists to find causes and treatments for numerous vascular diseases, such as diabetes, cancer, cardiovascular diseases, Alzheimer’s disease, stroke and wound healing problems.
Diabetes, in particular, affects nearly 420 million people all over the world. Most diabetic symptoms occur due to alterations in blood vessels that cause impaired oxygen supply and blood circulation in the body. Despite thousands of studies and recent advances in biomedicine, we still don’t know how these blood vessels change in diabetic patients.
To address this issue, researchers at the University of British Columbia have built an innovative model: they have grown perfect human blood vessel organoids in a petri dish, which mimic both the function and the structure of actual human blood vessels.
Vascular Organoids
These organoids (tiny, self-organized three-dimensional tissue cultures) are derived from stem cells. Their cells are grouped together and spatially arranged, similar to those of blood vessels.
To test these vascular organoids, researchers transplanted them into mice. They discovered that these organoids grew into perfectly functional human blood vessels, including capillaries and arteries. This indicates that along will engineering organoids from human stem cells in a dish, it is also possible to develop a functional human vascular system in other species.
Vascular organoids based on original data | Credit: IMBA
The vascular organoids developed in this study resemble human capillaries on a molecular scale. Thus, scientists can use them to examine diseases related to blood vessels, directly on human tissue. It wasn’t possible until now.
Reference: Nature | doi:10.1038/s41586-018-0858-8 | University of British Columbia
How This is Helpful for Diabetic Patients?
In diabetic patients, the basement membrane (shown in green) around the blood vessels (red) is abnormally thick. This prevents the vessels from properly delivering nutrients and oxygen to tissues and cells, which further causes a variety of health issues, ranging from heart attacks and kidney failure to blindness and peripheral artery disease.
Artificial vs real blood vessels in diabetic patients | Credit: IMBA
In this study, researchers exposed the artificial vessels to ‘diabetic’ conditions in a petri dish. A few moments later, they observed the same sort of enlargement of the basement membrane in the organoids which is seen in real blood vessels of diabetic patients.
Unfortunately, researchers didn’t find any chemical compound that could effectively block the expansion of blood vessel walls. They tested all possible anti-diabetic medications but none of them worked.
However, an inhibitor of gamma-secretase — a large multiprotein enzyme complex that catalyzes the intramembranous proteolysis of numerous type-1 proteins — was able to slightly prevent the thickening of the basement membrane in the vascular organoids. This observation suggests that we can use gamma-secretase to treat diabetes, at least in animal models.
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Moreover, the study could help scientists establish the underlying causes of vascular diseases and develop effective treatments for diabetic patients.
