Stem Cells Cause Clogged Arteries

illustration of how the newly discovered vascular stem cells can become smooth muscle, fat, cartilage or bone cells.
Within the walls of blood vessel are smooth muscle cells and newly discovered vascular stem cells. These stem cells are able to differentiate into smooth muscle, fat, cartilage and bone cells. (Song Li illustration)

Odds are that you know someone who’s had a heart attack. If you’re like me, you know many. One American suffers a coronary event every 25 seconds and about every minute someone dies from one.

Doctors thought they understood artery-hardening diseases that lead to heart attacks, strokes and death. But these theories have been contradicted by new research performed at the University of California, Berkeley. According to a new study published in Nature Communications, a previously unknown type of stem cell is actually the underlying cause for clogged arteries.

Researchers analyzed cells from blood vessels of transgenic mice and humans. They were able to trace the lineage of the cells that rapidly reproduced to cause a build up of fibrous scar tissue in the vessel walls. Current theories predicted these would be smooth muscle cells but instead they were a newly discovered type of stem cell.

Specifically they determined that the culprit behind clogged arteries are multipotent vascular stem cells that can develop into various specialized cells – smooth muscle, nerve, cartilage, bone and fat cells. This explains how arteries can calcify and harden, since the stem cells can form bone and cartilage.

If this research is verified in animals and humans by other research groups, this could lead to new therapies.

For more information about this research, check out my KQED Quest blog.

Curiosity and Nervousness over the Mars Landing

Artist's concept animation depicting the moment that NASA's Curiosity rover touches down onto Mars.
Artist’s animation depicting the moment that NASA’s Curiosity rover touches down onto Mars. (NASA/JPL-Caltech image)

When I tried to make lunch plans with a friend for next week, he didn’t know yet whether he could meet me. That’s because his plans depend on how smoothly the Curiosity rover lands on Mars tonight. His research team put together the Radiation Assessment Detector that is mounted on the top deck of the Curiosity rover.

NASA’s Mars Science Laboratory spacecraft with the Curiosity rover are approaching Mars at this moment. It’s expected to land tonight at 10:31 p.m. PDT (Pacific Daylight Time). The technical challenges involved in the Curiosity’s landing are daunting. The final minutes to landing are described beautifully in the NASA Jet Propulsion Laboratory’s popular video dubbed “The Seven Minutes of Terror.”

We still aren’t sure if life ever existed on Mars. From past missions, researchers know that there used to be water there. Now they want to determine if Mars once had the kind of environment that could be habitable or conducive for the formation of microbial life.

The Curiosity rover is a car-like rover that will search Mars for past or present conditions favorable for life on the planet. It is basically a science lab on wheels, including 10 complex scientific instruments. These instruments are designed to study the chemistry of rocks, soil and atmosphere — searching for signs of past life on Mars.

One of those scientific instruments is the Radiation Assessment Detector, which is designed to characterize the energetic particle spectrum at the surface of Mars. This will allow researchers to determine the radiation dose for humans at the planet surface, as well as provide input on the effects of particles on the surface and atmosphere. The surface is thought to have much higher radiation than Earth, since Mars has a thinner atmosphere and no global magnetic shield to divert charged particles.

Although all research requires patience, hurling your research instrument at a far away planet requires both patience and guts. The landing may cause 7 minutes of terror, but the days of waiting must include its own nail-biting nervousness. When I get together with my friend for lunch, I’ll check his nails. Hopefully the landing will be a success, so he’ll be at the Jet Propulsion Laboratory for the next couple weeks though. I can wait.

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