Wednesday, October 24, 2018

Using Stem Cells to Artificially Create the Blood-Brain Barrier

       There are millions of species that roam the Earth, most of which currently remain unknown to humans. It would be impossible to study every single one, so certain organisms have been chosen based on favorable characteristics to study the mechanisms of life. A model organism is then selected depending on the type of research being done. For example, the house mouse (Mus musculus) is commonly used in biomedical research as its anatomy and physiology is most similar to that of humans. However, there are still many differences between mice and humans that create complications, one such area being the blood-brain barrier (BBB) which prevents molecules in the blood from passing into the brain. While mice have a BBB, it’s significantly different from the one in humans which makes it hard to know whether research conducted in mice would be applicable to humans. Due to the important roles of the BBB, such as drug delivery to the brain, certain researchers have focused their efforts into finding a better system that more closely resembles the BBB in humans.

       Of course, what better system is there to use than humans themselves. Obviously, using humans in scientific research poses many ethical concerns and rarely ever happens, but what if there was a way to mimic the processes of the BBB in the lab. A recent study demonstrated a reproducible method for generating cells that make up the BBB from human pluripotent stem cells. These are cells capable of continuously dividing and producing any cell type in the human body. By introducing specific chemicals into human pluripotent stem cells, the researchers were able to induce differentiation into endothelial cells that make up the BBB. The future goal is to integrate generated endothelial cells with surrounding brain cells that other researchers discovered how to produce, and develop a complete model of the neurovascular unit. 

       This area of research is exciting for those in the biomedical industry as it could allow for newly developed drugs and treatments to be tested within a system that mimics human physiology. For example, new drugs could be tested to see how effective they are at crossing the BBB, a common problem when it comes to developing drugs that are required to reach the brain. Scientists are also attempting this type of study on larger scales by creating entirely artificial human organs, known as organoids. While much more research needs to be done, these studies are likely to influence biomedical research in the future.

Posted by Matt Murdoch (3)

7 comments:

  1. This is fascinating and something I have never heard of being done before. If scientists are actually able to generate cells that create the BBB that would be a huge advance in medicine. They would be able to do so much more than they are now and not even with just drugs and treatments.

    Posted by Danielle Bermingham

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    1. These types of studies often have to be repeated many times by many different people to confirm the truths and methods. This work has been reproduced by others and shows great promise for the future, but this is just one of many similar studies. Stem cell researchers have discovered the genes that cause differentiation for almost every cell in the body. Here is a really cool image showing the genes and they're interactions in causing differentiation. https://imgur.com/gallery/BIGq1a8

      -Matt Murdoch

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  2. Don't you need to create more than just the endothelial lining? It seems like there's still a lot more to be done. Now don't you also have the problem of where you get the stem cells? There's a lot of controversy surrounding stem cells too.

    Posted by Chandler Kupris

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    1. The study goes into some more depth about the cells they generated. Specifically, they are brain microvascular endothelial cells (BMEC) which for the most part make up the entire BBB, of course there are other surrounding glial cells as well. Also, I didn't mention it but probably should have, the human pluripotent stem cells come from adult human fibroblasts. Certain genes have been discovered that cause the reverse process of differentiation. The 2012 nobel prize for medicine or physiology was actually awarded for this discovery in mice, and was later adapted for human cells, which are used here to create the BMECs.

      -Matt Murdoch

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  3. The BBB is very important to keep any substance or molecules that could harm the brain out in the blood and not let it get into the brain cells. But this faces a real challenge for drugs that were invented to benefit the brain. These drug should penetrate the brain to act on the problems but the BBB is sometimes standing against these drugs that are analyzed as pathogens and not permitted to pass from the blood to the brain. This is a good way to look at this problem fro every drug that was invented to pass or even not to pass the brain. If this method of stem cells was successful for the BBB, it can be tried to make other types of cells or organs so then we can instead of using human in research ( which is unethical) to use these made organ.

    Posted by Jad Imad

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    1. This is exactly why research in this area is such a big deal. Researchers will eventually be able to use their own creations as preclinical models for whatever it is they are trying to study. The BBB is only one example of this, researchers could possibly generate nerve cells using a similar method to study certain diseases. The possibilities are endless and it's very exciting.

      -Matt Murdoch

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  4. It is a very fantastic topic. Now people can directly study human BBB without using human as experimental object. And since the BBB prevents molecules in the blood from passing into the brain, I think we can gain more knowledge about the diseases such as brain hemorrhage by studying BBB. Furthermore, I hope in the future we can also make other human organs by using stem cells, which may need us to study more about the differentiation mechanism of stem cells.

    Replied by Muchen Liu

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