Stem cell stories that caught our eye: heart disease, blindness and replacement teeth

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.

Review looks at approaches to blindness.
The Scientist published a nice lay level overview of various teams’ work to use stem cells to cure blindness. The bulk of the story covers age-related macular degeneration, the most common form of blindness in the elderly, with six approaches discussed and compared including the CIRM-funded California Project to Cure Blindness.

Dennis Clegg, one member of the California project team, was featured in a story posted by his university

The piece smartly includes an overview of the reasons eye diseases make up a disproportionate number of early stem cell trials using stem cells from sources other than bone marrow. Many in the field view it as the perfect target for early therapies where safety will be a main concern. It is a confined space so the cells are less likely to roam; it is small so fewer cells will be needed; and it has reduced immune activity so less likely to reject new cells.

The author describes three approaches to using cells derived from embryonic stem cells, one using iPS-type stem cells, one using fetal-derived nerve stem cells and one using cells from umbilical cord blood. An ophthalmologist from the University of Wisconsin who was not associated with any of the trials offered a fair assessment:

“We’re pushing the boundaries of this technology. And as such, we expect there to be probably more bumps in the road than smooth parts.”


A heart of gold, nanoparticles that is.
Most teams using scaffolds seeded with cells to create patches to strengthen damaged hearts start with animal material to create the scaffold, which can cause immune problems. An Israeli group has developed a way to use a patient’s own fat tissue to create these scaffolds. But that left the remaining problem of getting cells in a scaffold to beat in unison with the native heart. They found that by lacing the scaffold with gold nanoparticles they could create an effective conduction system for the heart’s electrical signals.

A story in ScienceDaily quotes the lead researcher Tal Dvir:

“The result was that the nonimmunogenic hybrid patch contracted nicely due to the nanoparticles, transferring electrical signals much faster and more efficiently than non-modified scaffolds.”

If you read the story parts of it are a little overwrought. The headline, “A Heartbeat away? Hybrid patch could replace transplants,” pushes credibility on two fronts. The first half suggests this therapy is imminent, rather than the reality of years away. Patches could only replace the need for transplants. They could never work as well as a full new heart, but since we only need partial function in our heart to live relatively OK, and they might be safer than a transplant they might replace the need.

Could teeth be first complex organ stem cell success? The Seattle Times did a pretty thorough story about why the tooth might be the first complex organ replaced via stem cells and regenerative medicine. While it is a complex organ with multiple layers, a blood system and a nervous system, it does not have moveable parts and we understand each part better than with other major organs.

The paper starts with a good reminder of just how far dental hygiene has come, with few elderly people needing dentures today—leaving the need for new teeth, suggests the author, to people such as hockey players.

A CIRM-funded team is investigating various ways to build a new tooth.

Even the Tea Party would like this regulation.
We have roughly as many genes as a frog, but are much more complicated. Our higher function evolved in part by making our genes more highly regulated. A CIRM-funded team now reports that this particularly applies to our “jumping genes,” and no that does not have anything to do with jumping frogs.

The work focuses on transposons, bits of our DNA that literally move around, or jump, between our functional genes and change how they are turned on or off. We also have evolved a set of genes to control the jumping genes, and the researchers at the University of California, Santa Cruz, suggest that evolution has been a never ending tug of war between the jumping genes and the genes that are supposed to control them.

HealthCanal ran the university’s press release, which quotes lead researcher Sofie Salama:

“We have basically the same 20,000 protein-coding genes as a frog, yet our genome is much more complicated, with more layers of gene regulation. This study helps explain how that came about.”

Don Gibbons

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