Posts Tagged ‘vessel’



When white blood cells leave a vessel through the vessel wall, they contort their shape to pass through.  But when stem cells exit a blood vessel, they don’t change their shape.  They just pass on through the wall and the endothelial cells lining the vessel do the work by stretching around them and then actively expelling them.   In other words, the stem cells are the Moses to the parting of the cells of the blood vessels:
“…when we looked at therapeutic stem cells… the endothelial cells not only changed their shape in order to surround the stem cell, they actually pushed the stem cells out of the blood vessel. We’ve named this process angiopellosis, and it represents an alternative way for cells to leave blood vessels.”  Which begs the question…is this how cancer cells move around too?

Stem Cell Finding May Improve Understanding of Metastatic Cancers

  • A stem cell exits the bloodstream through angiopellosis. [Alice MacGregor Harvey, North Carolina State University]

  • Researchers at North Carolina State University have discovered that therapeutic stem cells exit the bloodstream in a different manner than was previously thought. This process, called angiopellosis by the researchers, has implications for improving our understanding of not only intravenous stem cell therapies, but also metastatic cancers.

    When white blood cells need to get to the site of an infection, they can exit the bloodstream via a process known as diapedesis. In diapedesis, the white blood cell changes its shape to squeeze between or through the epithelial cells that form the walls of the blood vessel. Diapedesis is a well-understood process, and researchers believed that other types of cells, like therapeutic stem cells or even metastatic cancer cells, exited blood vessels in a similar way, with the cells pushing or squeezing themselves out.

    But a group of researchers led by Ke Cheng, Ph.D., associate professor of molecular biomedical sciences at NC State with a joint appointment in the NC State/University of North Carolina (UNC)-Chapel Hill Department of Biomedical Engineering, found that these stem cells behaved differently. Their study (“Angiopellosis as an Alternative Mechanism of Cell Extravasation”) appears online in Stem Cells.

    Therapeutic stem cells share the same ability to exit the bloodstream and target particular tissues that white blood cells do. But the precise way that they did so was not well understood, so Dr. Cheng and his team used a zebrafish model to study the process. The genetically modified zebrafish embryos were transparent and had fluorescently marked green blood vessels. Researchers injected the embryos with white blood cells and cardiac stem cells from humans, rats, and dogs. These cells had all been marked with a red fluorescent protein.

    Through time-lapse, three-dimensional, light sheet microscopic imaging, Dr. Cheng and his team could trace the progress of these cells as they left the blood vessel. The white blood cells exited via diapedesis, as expected. When stem cells exited the blood vessel, however, the endothelial cells lining the vessel actively expelled them. Membranes surrounding the endothelial cells on either side of the stem cell stretched themselves around the stem cell, then met in the middle to push the stem cell out of the vessel.

    “When you’re talking about diapedesis, the white blood cell is active because it changes its shape in order to exit. The endothelial cells in the blood vessel are passive,” Dr. Cheng says. “But when we looked at therapeutic stem cells, we found the opposite was true—the stem cells were passive—and the endothelial cells not only changed their shape in order to surround the stem cell, they actually pushed the stem cells out of the blood vessel. We’ve named this process angiopellosis, and it represents an alternative way for cells to leave blood vessels.”

    The researchers found two other key differences between angiopellosis and diapedesis: one, that angiopellosis takes hours, rather than minutes, to occur and two, that angiopellosis allows more than one cell to exit at a time.

    “Angiopellosis is really a group ticket for cells to get out of blood vessels,” notes Dr. Cheng. “We observed clusters of cells passing through in this way. Obviously, this leads us to questions about whether other types of cells, like metastatic cancer cells, may be using this more effective way to exit the bloodstream, and what we may need to do to stop them.”





In STEM CELLS IN THE NEWS on April 23, 2012 at 10:08 pm


New stem cell found in the brain

Researchers at Lund University have discovered a new stem cell in the adult brain. These cells can proliferate and form several different cell types – most importantly, they can form new brain cells. Now the researchers hope to put the discovery to use to develop methods that can repair diseases and injury to the brain.

Analysing brain tissue from biopsies, the researchers for the first time found stem cells located around small blood vessels in the brain. The cell’s specific function is still unclear, but its plastic properties suggest great potential. A similar cell type has been identified in several other organs where it can promote regeneration of muscle, bone, cartilage and adipose tissue.

In other organs, researchers have shown clear evidence that these types of cells contribute to repair and wound healing. Scientists suggest that the curative properties may also apply to the brain. The next step is to try to control and enhance stem cell self-healing properties with the aim of carrying out therapies targeted to a specific area of the brain.

“Our findings show that the cell capacity is much larger than we originally thought, and that these cells are very versatile,” said Gesine Paul-Visse, Ph.D., Associate Professor of Neuroscience at Lund University.

“Most interesting is their ability to form neuronal cells, but they can also be developed for other cell types. The results contribute to better understanding of how brain cell plasticity works and opens up new opportunities to exploit these very features.”

The study, published in the journal PLoS ONE, is of interest to a broad spectrum of brain research. Future possible therapeutic targets range from neurodegenerative diseases to stroke.

“We hope that our findings may lead to a new and better understanding of the brain’s own repair mechanisms,” said Dr. Paul-Visse. “Ultimately the goal is to strengthen these mechanisms and develop new treatments that can repair the diseased brain.”


Link to the study here:


The study:

Title: The Adult Human Brain Harbors Multipotent Perivascular Mesenchymal Stem Cells Published in: PLoS ONE, 16 April, 2012.

New stem cell found in the brain.


In OFF THE BEATEN PATH on March 10, 2011 at 9:22 am


Eating certain foods may cut off the blood supply to tumors forming and existing in your body

by David Granovsky on Wednesday, March 9, 2011 at 9:19pm


This video ties together many of my beliefs. Here is a simple summation of the 18 minute video for educational purposes:

We know that not eating certain foods will reduce incidence of cancer but did you know that eating certain foods will reduce the incidence, growth and severity of cancer?

You can in fact eat foods that will turn on a response in your body to fight many diseases. In this case, the foods you eat actively starve and destroy the blood vessels feeding the tumors, thereby starving the tumor of nutrients and oxygen and thereby destroying the tumor. Blood vessel growth is angiogenesis, blood vessel starvation is called anti-angiogenesis.

Foods that promote anti-angiogenesis should be purchased from local, organic growers (less shipping, more ripe, less pesticides, etc) and the more of them you eat, the more effect they are.

In most cases, the foods should be eaten in the most raw and unrefined state you can get them except tomatoes which seem to be more effective when cooked. 79,000 men were studied and those that ate tomatoes 2-3x per week had 40-50% less incidence of prostate cancer.

The veggies can be juiced so you can consume more of the nutrients and less of the fiber. I can drink 2 heads of celery and 3 bunches of parsley a day when juiced…but if I tried to eat that in a raw salad form I would be bound up for a week.

AND, the more anti-angiogenisis foods you eat, the a huge side benefit is getting thinner. Obesity and cancer are directly related. Reduce the abnormal blood vessel growth associated with cancer and you will reduce the blood vessel growth in your fat (and vice versa) and you get thinner and healthier. This is seen in the book The Okinawa Diet that showed that the less obese you are the less cancer incidence.

For more detailed info:



Nanoparticles + Stem Cells = Faster Healing Wounds

In SCIENCE & STEM CELLS on October 8, 2009 at 4:47 pm

Nanoparticles + Stem Cells = Faster Healing Wounds

Blood vessel

A new study may have hit upon another way to improve stem cells‘ ability to help repair damaged tissue. While stem cells can rapidly grow into any kind of new tissue, they aren’t always able to encourage new blood vessels to grow so that the tissue stays alive. But in a new study, published in the Proceedings of the National Academy of Sciences, scientists describe a way around the problem. The researchers used nanoparticles to ferry a key gene into the stem cells, which caused the cells to recruit new blood vessels, thus fueling tissue growth.


Nano particle

The nanoparticles carried a gene (VEGF) that is known to stimulate new blood vessel growth. When the modified cells were injected into mice whose hind limbs had been injured, the tissue that regrew to repair the damage had three times the blood vessel density of similar tissue in mice given unmodified cells. Four weeks later, only 20 per cent of the mice given modified cells had lost limbs, compared with 60 per cent in mice that received unmodified cells [New Scientist].


Nano particle

The researchers are optimistic about the nanoparticle approach, however they state in the study that the effect may be transient. They note that there was a significant increase in VEGF levels in mouse muscle two days following cell grafting, but VEGF levels produced by the cells dropped sharply after four days [The Scientist]. They say that using a virus to transmit the gene may be a better approach to stimulate new blood vessels over a longer period of time. However, the viral approach is not without risks–viruses can integrate into the genome of cells and linger permanently, potentially causing cancer or immune reactions [Bloomberg].

via Nanoparticles + Stem Cells = Faster Healing Wounds | 80beats | Discover Magazine.

%d bloggers like this: