Adult Stem Cells Help Build Human Blood Vessels in Engineered Tissues

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[Writer] This is research news from UIC – the University of Illinois at Chicago.

Today, Dr. Jalees Rehman, associate professor of cardiology and pharmacology in the UIC College of Medicine will talk about his recent study on how stem cells can promote the development of blood vessels in engineered tissues.

Here’s Dr. Rehman.

[Rehman] My name is Jalees Rehman. I’m a stem cell biologist and a cardiologist at the University of Illinois at Chicago and my research laboratory studies how stem cells can be used to build blood vessels and improve the function of the heart and other cardiovascular tissues. Today I would like to talk about a new study we are publishing in the Journal of Molecular and Cellular Cardiology. In this study we wanted to understand how do mesenchymal stem cells – MSCs – derived from the bone marrow, help build functional blood vessels.

We used bone marrow-derived mesenchymal stem cells from humans and mixed them together with endothelial cells – these are the cells that line blood vessels, and we observed how the MSCs were able to construct a vascular network that was able to be perfused with blood. This means that this simple mixing process created functional blood vessels that could be potentially implanted into patients who have severe blockages in their blood vessels and need fresh new regenerated blood vessels to provide oxygen to their tissues.

However, to our surprise we noticed, not all adult stem cells were equally good at supporting the formation of vascular networks. One mesenchymal stem cell line for example, was not able to create any vascular networks, whereas another stem cell line was five times better at creating blood vessel networks. So we performed a gene array analysis and wanted to identify the signature that supports blood vessel formation. To our surprise we observed that a protein called SLIT3, S-L-I-T-3, was released by the mesenchymal stem cells which were able to promote blood vessel network formation. The reason why it was surprising was that SLIT3 was generally considered to be a protein released by neurons in the nervous system and guide blood vessel formation in the nervous system.

It appeared that bone marrow mesenchymal stem cells use a similar mechanism to guide the formation of blood vessels. And, SLIT3 allowed us to distinguish between the MSCs which were good at forming blood vessels and the ones which were not. When we then took a mixture of mesenchymal stem cells and removed the SLIT3 protein from the mixture, the cells were unable to form any kind of network. What this tells us is that not all stem cells are created equal. Some stem cells are very good at promoting blood vessel growth and others are not. This may explain why in the current clinical trials which use adult mesenchymal stem cells to treat heart patients, the benefits have been rather modest.

Maybe some patients are being treated with their own stem cells even though their stem cells are not very good at supporting blood vessel formation. And maybe if we tried to find the signature of every single person’s stem cells and perhaps even correct that by giving them SLIT3 if they lack it, we might be able to engineer functional blood vessels in all patients.

[Writer] Dr. Rehman is an associate professor of cardiology and pharmacology. For more information about this research, go to www-dot-news-dot-uic-dot-edu and click on news releases. Then look for the release titled “Adult stem cells help build human blood vessels in engineered tissues.”

This has been research news from UIC – the University of Illinois at Chicago.