Goodnight, Stem Cells: How Well Rested Cells Keep Us Healthy

Plenty of studies show that a lack of sleep is nothing but bad news and can contribute to a whole host of health problems like heart disease, poor memory, high blood pressure and obesity.

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Even stem cells need rest to stay healthy

In a sense, the same holds true for the stem cells in our body. In response to injury, adult stem cells go to work by dividing and specializing into the cells needed to heal specific tissues and organs. But they also need to rest for long-lasting health. Each cell division carries a risk of introducing DNA mutations—and with it, a risk for cancer. Too much cell division can also deplete the stem cell supply, crippling the healing process. So it’s just as important for the stem cells to assume an inactive, or quiescent, state to maintain their ability to mend the body. Blood stem cells for instance are mostly quiescent and only divide about every two months to renew their reserves.

Even though the importance of this balance is well documented, exactly how it’s achieved is not well understood; that is, until now. Earlier this week, a CIRM-funded research team from The Scripps Research Institute (TSRI) reported on the identification of an enzyme that’s key in controlling the work-rest balance in blood stem cells, also called hematopoietic stem cells (HSCs). Their study, published in the journal Blood, could point the way to drugs that treat anemias, blood cancers, and other blood disorders.

Previous studies in other cell types suggested that this key enzyme, called ItpkB, might play a role in promoting a rested state in HSCs. Senior author Karsten Sauer explained their reasoning for focusing on the enzyme in a press release:

“What made ItpkB an attractive protein to study is that it can dampen activating signaling in other cells. We hypothesized that ItpkB might do the same in HSCs to keep them at rest. Moreover, ItpkB is an enzyme whose function can be controlled by small molecules. This might facilitate drug development if our hypothesis were true.”

Senior author Karsten Sauer is an associate professor at The Scripps Research Institute.

Senior author Karsten Sauer is an associate professor at The Scripps Research Institute.

To test their hypothesis, the team studied HSCs in mice that completely lacked ItpkB. Sure enough, without ItpkB the HSCs got stuck in the “on” position and continually multiplied until the supply of HSCs stores in the bone marrow were exhausted. Without these stem cells, the mice could no longer produce red blood cells, which deliver oxygen to the body or white blood cells, which fight off infection. As a result the animals died due to severe anemia and bone marrow failure. Sauer used a great analogy to describe the result:

“It’s like a car—you need to hit the gas pedal to get some activity, but if you hit it too hard, you can crash into a wall. ItpkB is that spring that prevents you from pushing the pedal all the way through.”

With this new understanding of how balancing stem cell activation and deactivation works, Sauer and his team have their sights set on human therapies:

“If we can show that ItpkB also keeps human HSCs healthy, this could open avenues to target ItpkB to improve HSC function in bone marrow failure syndromes and immunodeficiencies or to increase the success rates of HSC transplantation therapies for leukemias and lymphomas.”

Stem Cell Stories that Caught our Eye: What’s the Best Way to Treat Deadly Cancer, Destroying Red Blood Cells’ Barricade, Profile of CIRM Scientist Denis Evseenko

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Stem Cells vs. Drugs for Treating Deadly Cancer. When dealing with a potentially deadly form of cancer, choosing the right treatment is critical. But what if that treatment also poses risks, especially for older patients? Could advances in drug development render risky treatments, such as transplants, obsolete?

That was the focus of a pair of studies published this week in the New England Journal of Medicine, where a joint Israeli-Italian research team investigated the comparative benefits of two different treatments for a form of cancer called multiple myeloma.

Multiple myeloma attacks the body’s white blood cells. While rare, it is one of the most deadly forms of cancer—more than half of those diagnosed with the disease do not survive five years after being diagnosed. The standard form of treatment is usually a stem cell transplant, but with newer and better drugs coming on the market, could they render transplants unnecessary?

In the twin studies, the research team divided multiple myeloma patients into two groups. One received a combination of stem cell transplant and chemotherapy, while the other received a combination of drugs including melphalan, prednisone and lenalidmomide. After tracking these patients over a period of four years, the research team saw a clear advantage for those patients that had received the transplant-chemotherapy treatment combination.

To read more about these twin studies check out recent coverage in NewsMaxHealth.

Breaking Blood Cells’ Barricade. The process whereby stem cells mature into red blood cells is, unfortunately, not as fast as scientists would like. In fact, there is a naturally occurring barrier that keeps the production relatively slow. In a healthy person this is not necessarily a problem, but for someone in desperate need of red blood cells—it can prove to be very dangerous.

Luckily, scientists at the University of Wisconsin-Madison have found a way to break through this barrier by switching off two key proteins. Once firmly in the ‘off’ position, the team could boost the production of red blood cells.

These findings, published in the journal Blood, are critical in the context of disease anemia, where the patient’s red blood cell count is low. They also may lead to easier methods of stocking blood banks.

Read more about this exciting discovery at HealthCanal.

CIRM Scientist on the Front Lines of Cancer. Finally, HealthCanal has an enlightening profile of Dr. Denis Evseenko, a stem cell scientist and CIRM grantee from the University of California, Los Angeles (UCLA).

Born in Russia, the profile highlights Evseenko’s passion for studying embryonic stem cells—and their potential for curing currently incurable diseases. As he explains in the article:

“I had a noble vision to develop progressive therapies for the patient. It was a very practical vision too, because I realized how limited therapeutic opportunities could be for the basic scientist, and I had seen many great potential discoveries die out before they ever reached the clinic. Could I help to create the bridge between stem cells, research and actual therapeutics?”

Upon arriving at UCLA, Evseenko knew he wanted to focus this passion into the study of degenerative diseases and diseases related to aging, such as cancer. His bold vision of bridging the gap between basic and translational research has earned him support not only from CIRM, but also the National Institutes of Health and the US Department of Defense, among others. Says Evseenko:

“It’s my hope that we can translate the research we do and discoveries we make here to the clinic to directly impact patient care.”