Caption: Zika virus (red), isolated from a microcephaly case in Brazil. The virus is associated with cellular membranes in the center. Credit: NIAID
Last February, the World Health Organization declared a public health emergency over concerns about very serious birth defects in Brazil and their possible link to Zika virus. But even before then, concerns about the unprecedented spread of Zika virus in Brazil and elsewhere in Latin America had prompted NIH-funded scientists to step up their efforts to combat this emerging infectious disease threat. Over the last year, research aimed at understanding the mosquito-borne virus has progressed rapidly, and we now appear to be getting closer to a Zika vaccine.
In a recent study in the journal Nature, researchers found that a single dose of either of two experimental vaccines completely protected mice against a major viral strain responsible for the Zika outbreak in Brazil . Caution is certainly warranted when extrapolating these (or any other) findings from mice to people. But, taking into account the fact that researchers have already developed safe and effective human vaccines for several related viruses, the new work represents a very encouraging milestone on the road toward a much-needed Zika vaccine for humans.
This Fourth of July, many of you will spread out a blanket and enjoy an evening display of fireworks with their dramatic, colorful bursts. But here’s one pyrotechnic pattern that you’ve probably never seen. In this real-time video, researchers set off some fluorescent fireworks under their microscope lens while making an important basic discovery about how microtubules, the hollow filaments that act as the supportive skeleton of the cell, dynamically assemble during cell division.
The video starts with a few individual microtubule filaments (red) growing linearly at one end (green). Notice the green “comets” that quickly appear, followed by a red trail. Those are new microtubules branching off. This continuous branching is interesting because microtubules were generally thought to grow linearly in animal cells (although branching had been observed a few years earlier in fission yeast and plant cells). The researchers, led by Sabine Petry, now at Princeton University, Princeton, NJ, showed for the first time that not only do new microtubules branch during cell division, but they do so very rapidly, going from a few branches to hundreds in a matter of minutes .
We all know that exercise is important for a strong and healthy body. Less appreciated is that exercise seems also to be important for a strong and healthy mind, boosting memory and learning, while possibly delaying age-related cognitive decline . How is this so? Researchers have assembled a growing body of evidence that suggests skeletal muscle cells secrete proteins and other factors into the blood during exercise that have a regenerative effect on the brain.
Now, an NIH-supported study has identified a new biochemical candidate to help explore the muscle-brain connection: a protein secreted by skeletal muscle cells called cathepsin B. The study found that levels of this protein rise in the blood of people who exercise regularly, in this case running on a treadmill. In mice, brain cells treated with the protein also exhibited molecular changes associated with the production of new neurons. Interestingly, the researchers found that the memory boost normally provided by exercise is diminished in mice unable to produce cathepsin B.
Jenolyn F. Alexander and Biana Godin, Houston Methodist Research Institute; Veronika Kozlovskaya and Eugenia Kharlampieva, University of Alabama at Birmingham.
Creative photographers have long experimented with superimposing images, one over the other, to produce striking visual effects. Now a group of NIH-supported scientists at Houston Methodist Research Institute and their colleagues have done the same thing to highlight their work in the emerging field of cancer nanomedicine, using microscopic materials to deliver cancer treatments with potentially greater precision. In the process, the researchers generated a photographic work of art that was a winner in the Federation of American Societies for Experimental Biology 2015 Bioart competition.
The gold cubes are man-made polymer microcarriers, just 2 micrometers wide (by comparison, human cells generally range in diameter from 7 to 20 micrometers), designed to transport chemotherapy drugs directly to tumor cells. These experimental cubes, enlarged in the upper left part of the photo with a scanning electron microscope for better viewing, have been superimposed onto a second photograph snapped with a confocal fluorescence microscope. It shows similar cube-shaped microcarriers (yellow) inside cultured breast cancer cells (nucleus is purple, cytoplasm is turquoise).
Tony Wyss-Coray / Credit: Stanford School of Medicine
Basic scientists have long studied aging by looking inside of cells. While this research has produced many important leads, they are now starting to look outside the cell for the wealth of biochemical clues contained in the bloodstream.
To introduce you to this exciting frontier in aging research, this blog highlighted a while back the work of Tony Wyss-Coray at Stanford School of Medicine, Palo Alto, CA. He and a colleague had just received a 2013 NIH Director’s Transformative Research Award to explore the effects of exercise on the brains of mice. Their work, in fact, produced one of Science Magazine’s Breakthrough Discoveries of 2014. Their team showed that by fusing the circulatory systems of old and young mice to create a shared blood supply, the young blood triggered new muscle and neural connections in the older mice, while also improving their memories.
As fascinating as this theoretical Fountain of Youth was, Wyss-Coray recognized a critical limitation. He had no way of knowing how factors secreted by the young mouse could actually cross the blood-brain barrier and rejuvenate neurons. To solve this unknown, Wyss-Coray recently received a 2015 NIH Director’s Pioneer Award to build a potentially game-changing tool to track the aging process in mice.