Caption: Heart microchamber generated from human iPS cells; cardiomyocytes (red), myofibroblasts (green), cell nuclei (blue) Credit: Zhen Ma, University of California, Berkeley
The adult human heart is about the size of a large fist, divided into four chambers that beat in precise harmony about 100,000 times a day to circulate blood throughout the body. That’s a very dynamic system, and also a very challenging one to study in real-time in the lab. Understanding how the heart forms within developing human embryos is another formidable challenge. So, you can see why researchers are excited by the creation of tiny, 3D heart chambers with the ability to exist (see image above) and even beat (see video below) in a lab dish, or as scientists say “in vitro.”
Credit: Zhen Ma et al., Nature Communications
To achieve this feat, an NIH-funded team from University of California, Berkeley, and Gladstone Institute of Cardiovascular Disease, San Francisco turned to human induced pluripotent stem (iPS) cell technology. The resulting heart chambers may be miniscule—measuring no more than a couple of hair-widths across—but they hold huge potential for everything from improving understanding of cardiac development to speeding drug toxicity screening.
When most people think about risk factors for cardiovascular disease, they likely think of blood pressure readings or cholesterol levels. But here’s something else that should be high on that list: diabetes. That’s because people with diabetes are roughly twice as likely to die of heart disease than other folks . Yet the issue of how best to help such people lower their cardiovascular risks remains a matter of intense debate. Some studies have suggested that part of the answer may lie in tightly controlling blood sugar (glucose) levels with a strict regimen of medications and monitoring . Other research has shown that the intense effort needed to keep blood glucose levels under tight control might not be worth it and may even make things worse for certain individuals .
Now, a follow up of a large, clinical trial involving nearly 1,800 U.S. military veterans with type 2 diabetes—the most common form of diabetes—provides further evidence that tight blood glucose control may indeed protect the cardiovascular system. Reporting in The New England Journal of Medicine , researchers found a significant reduction in a composite measure of heart attacks, strokes, heart failure, and circulation-related amputations among the vets who maintained tight glucose control for about five and a half years on average. What’s particularly encouraging is most of the cardiovascular-protective benefit appears to be achievable through relatively modest, rather than super strict, reductions in blood glucose levels.
Caption: [A] Elastin stain (black) showing damaged elastic lamina in aorta. Inset (higher magnification) shows fluorescent nanoparticles attached to aorta where elastin is damaged. [B] Elastin stain showing aorta with undamaged elastic lamina. Inset shows no nanoparticle attachment. L stands for lumen, the open area inside the aorta. Credit: Naren Vyavahare, Clemson University
Cardiovascular disease (CVD) is the number one killer of Americans. There are, in fact, many types of CVD—but common to most of them is damaged blood vessels. Stents can be inserted to prop open collapsed or narrowed arteries, and deliver drugs inside vessels. But, so far, we haven’t been able to repair the damaged vessels themselves. Researchers in an NIH-funded team of bioengineers at Clemson University, in South Carolina, are among those who believe that delivering drugs directly to the site of damage to mend the vessel might boost our ability to treat CVDs. And they’ve devised a way to deliver such drugs right where they want them: using specially-crafted nanoparticles.
Caption: Illustration of artery partially blocked by a cholesterol plaque.
If you’re concerned about your cardiovascular health, you’re probably familiar with “good” and “bad” cholesterol: high-density lipoprotein (HDL) and its evil counterpart, low-density lipoprotein (LDL). Too much LDL floating around in your blood causes problems by sticking to the artery walls, narrowing the passage and raising risk of a stroke or heart attack. Statins work to lower LDL. HDL, on the other hand, cruises through your arteries scavenging excess cholesterol and returning it to the liver, where it’s broken down.