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.
Understanding Heart Defects. Healthy heart tissue is made up of smooth, solid muscle, which is essential for normal heart function. Patients with a heart defect called left ventricular non-compaction (LVNC), lack normal heart tissue in their left ventricle – the largest, strongest blood-pumping chamber – and instead have spongy-looking tissue.
LVNC occurs during early heart development where pieces of heart muscle fail to condense (compact) and instead form an airy, sponge-like network that can leave patients at risk for heart failure and other complications.
A team at Stanford is interested in learning how LVNC occurs in humans, and they’re using human stem cells for the answer. Led by CIRM grantee Joe Wu, the scientists generated induced pluripotent stem cells (iPSCs) from four patients with LVNC. iPSCs are cells that can be turned into any other cell in the body, so Wu turned these cells into iPSC-derived heart muscle in a dish.
Wu’s team was particularly interested in determining why some LVNC patients have symptoms of disease while others seem perfectly normal. After studying the heart muscle cells derived from the four LVNC patients, they identified a genetic mutation in a gene called TBX20. This gene produces a type of protein called a cardiac transcription factor, which controls the expression of other heart related genes.
Upon further exploration, the scientists found that the genetic mutation in TBX20 prevented LVNC heart muscle cells from dividing at their normal rate. If they blocked the signal of mutant TBX20, the heart cells went back to their normal activity and created healthy looking heart tissue.
This study was published in Nature Cell Biology and covered by the Stanford Medicine Scope blog. In an interview with Scope, Joe Wu highlighted the big picture of their work:
“This study shows the feasibility of modeling such developmental defects using human tissue-specific cells, rather than relying on animal cells or animal models. It opens up an exciting new avenue for research into congenital heart disease that could help literally the youngest — in utero — patients.”
Stem Cell Heart Patch. Scientists from the University of Wisconsin, Madison are creating stem cell-based heart patches that they hope one day could be used to treat heart disease.
In a collaboration with Duke and the University of Alabama at Birmingham, they’re developing 3D stem cell-derived patches that contain the three main cell types found in the heart: cardiomyocytes (heart muscle cells), fibroblasts (support cells), and endothelial cells (cells that line the insides of blood vessels). These patches would be transplanted into heart disease patients to replace damaged heart tissue and improve heart function.
As with all research that has the potential for reaching human patients, the scientists must first determine whether the heart patches are safe in animal models. They plan to transplant the heart patches into a pig model – chosen because pigs have similar sized hearts compared to humans.
In a UW-Madison News release, the director of the UW-Madison Stem Cell and Regenerative Medicine Center Timothy Kamp, hinted at the potential for this technology to reach the clinic.
“The excitement here is we’re moving closer to patient applications. We’re at a stage when we need to see how these cells do in a large animal heart attack model. We’ll be making patches of heart muscle that can be applied to these injured areas.”
Kamp and his team still have a lot of work to do to perfect their heart patch technology, but they are thinking ahead. Two issues that they are trying to address are how to prevent a patient’s immune system from rejecting the heart patch transplant, and how to make sure the heart patches beat in sync with the heart they are transplanted into.
Check out the heart patches in action in this video:
(Video courtesy of Xiaojun Lian)
Cool Stem Cell Art! When I was a scientist, I worked with stem cells all the time. I grew them in cell culture dishes, coaxed them to differentiate into brain cells, and used a technique called immunostaining to take really beautiful, colorful pictures of my final cell products. I took probably thousands of pictures over my PhD and postdoc, but sadly, only a handful of these photos ever made it into journal publications. The rest collected dust either on my hard drive or in my lab notebook.
It’s really too bad that at the time I didn’t know about this awesome stem cell art contest called Cells I See run by the Centre for Commercialization of Regenerative Medicine (CCRM) in Ontario Canada and sponsored by the Stem Cell Network.
The contest “is about the beauty of stem cells and biomaterials, seen directly through the microscope or through the interpretive lens of the artist.” Scientists can submit their most prized stem cell images or art, and the winner receives a cash prize and major science-art street cred.
The submission deadline for this year’s contest was earlier this month, and you can check out the contenders on CCRM’s Facebook page. Even better, you can vote for your favorite image or art by liking the photo. The last date to vote is October 15th and the scientist whose image has the most likes will be the People’s Choice winner. CCRM will also crown a Grand Prize winner at the Till & McCulloch Stem Cell Meeting in October.
I’ll leave you with a few of my favorite photos, but please don’t let this bias your vote =)!