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Biomedical Research Highlighted in Science’s 2018 Breakthroughs

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Science Breakthroughs of the Year 2018

A Happy New Year to one and all! While many of us were busy wrapping presents, the journal Science announced its much-anticipated scientific breakthroughs of 2018. In case you missed the announcement [1], it was another banner year for the biomedical sciences.

The 2018 Breakthrough of the Year went to biomedical science and its ability to track the development of life—one cell at a time—in a variety of model organisms. This newfound ability opens opportunities to understand the biological basis of life more systematically than ever before. Among Science’s “runner-up” breakthroughs, more than half had strong ties to the biomedical sciences and NIH-supported research.

Sound intriguing? Let’s take a closer look at some of the amazing science conducted in 2018, starting with Science’s Breakthrough of the Year.

Development Cell by Cell: For millennia, biologists have wondered how a single cell develops into a complete multicellular organism, such as a frog or a mouse. But solving that mystery was almost impossible without the needed tools to study development systematically, one cell at a time. That’s finally started to change within the last decade. I’ve highlighted the emergence of some of these powerful tools on my blog and the interesting ways that they were being applied to study development.

Over the past few years, all of this technological progress has come to a head. Researchers, many of them NIH-supported, used sophisticated cell labeling techniques, nucleic acid sequencing, and computational strategies to isolate thousands of cells from developing organisms, sequence their genetic material, and determine their location within that developing organism.

In 2018 alone, groundbreaking single-cell analysis papers were published that sequentially tracked the 20-plus cell types that arise from a fertilized zebrafish egg, the early formation of organs in a frog, and even the creation of a new limb in the Axolotl salamander. This is just the start of amazing discoveries that will help to inform us of the steps, or sometimes missteps, within human development—and suggest the best ways to prevent the missteps. In fact, efforts are now underway to gain this detailed information in people, cell by cell, including the international Human Cell Atlas and the NIH-supported Human BioMolecular Atlas Program.

An RNA Drug Enters the Clinic: Twenty years ago, researchers Andrew Fire and Craig Mello showed that certain small, noncoding RNA molecules can selectively block genes in our cells from turning “on” through a process called RNA interference (RNAi). This work, for the which these NIH grantees received the 2006 Nobel Prize in Physiology or Medicine, soon sparked a wave of commercial interest in various noncoding RNA molecules for their potential to silence the expression of a disease-causing gene.

After much hard work, the first gene-silencing RNA drug finally came to market in 2018. It’s called Onpattro™ (patisiran), and the drug uses RNAi to treat the peripheral nerve disease that can afflict adults with a rare disease called hereditary transthyretin-mediated amyloidosis. This hard-won success may spark further development of this novel class of biopharmaceuticals to treat a variety of conditions, from cancer to cardiovascular disorders, with potentially greater precision.

Rapid Chemical Structure Determination: Last October, two research teams released papers almost simultaneously that described an incredibly fast new imaging technique to determine the structure of smaller organic chemical compounds, or “small molecules“ at atomic resolution. Small molecules are essential components of molecular biology, pharmacology, and drug development. In fact, most of our current medicines are small molecules.

News of these papers had many researchers buzzing, and I highlighted one of them on my blog. It described a technique called microcrystal electron diffraction, or MicroED. It enabled these NIH-supported researchers to take a powder form of small molecules (progesterone was one example) and generate high-resolution data on their chemical structures in less than a half-hour! The ease and speed of MicroED could revolutionize not only how researchers study various disease processes, but aid in pinpointing which of the vast number of small molecules can become successful therapeutics.

How Cells Marshal Their Contents: About a decade ago, researchers discovered that many proteins in our cells, especially when stressed, condense into circumscribed aqueous droplets. This so-called phase separation allows proteins to gather in higher concentrations and promote reactions with other proteins. The NIH soon began supporting several research teams in their groundbreaking efforts to explore the effects of phase separation on cell biology.

Over the past few years, work on phase separation has taken off. The research suggests that this phenomenon is critical in compartmentalizing chemical reactions within the cell without the need of partitioning membranes. In 2018 alone, several major papers were published, and the progress already has some suggesting that phase separation is not only a basic organizing principle of the cell, it’s one of the major recent breakthroughs in biology.

Forensic Genealogy Comes of Age: Last April, police in Sacramento, CA announced that they had arrested a suspect in the decades-long hunt for the notorious Golden State Killer. As exciting as the news was, doubly interesting was how they caught the accused killer. The police had the Golden Gate Killer’s DNA, but they couldn’t determine his identity, that is, until they got a hit on a DNA profile uploaded by one of his relatives to a public genealogy database.

Though forensic genealogy falls a little outside of our mission, NIH has helped to advance the gathering of family histories and using DNA to study genealogy. In fact, my blog featured NIH-supported work that succeeded in crowdsourcing 600 years of human history.

The researchers, using the online profiles of 86 million genealogy hobbyists with their permission, assembled more than 5 million family trees. The largest totaled more than 13 million people! By merging each tree from the crowd-sourced and public data, they were able to go back about 11 generations—to the 15th century and the days of Christopher Columbus. Though they may not have caught an accused killer, these large datasets provided some novel insights into our family structures, genes, and longevity.

An Ancient Human Hybrid: Every year, researchers excavate thousands of bone fragments from the remote Denisova Cave in Siberia. One such find would later be called Denisova 11, or “Denny” for short.

Oh, what a fascinating genomic tale Denny’s sliver of bone had to tell. Denny was at least 13 years old and lived in Siberia roughly 90,000 years ago. A few years ago, an international research team found that DNA from the mitochondria in Denny’s cells came from a Neanderthal, an extinct human relative.

In 2018, Denny’s family tree got even more interesting. The team published new data showing that Denny was female and, more importantly, she was a first generation mix of a Neanderthal mother and a father who belonged to another extinct human relative called the Denisovans. The Denisovans, by the way, are the first human relatives characterized almost completely on the basis of genomics. They diverged from Neanderthals about 390,000 years ago. Until about 40,000 years ago, the two occupied the Eurasian continent—Neanderthals to the west, and Denisovans to the east.

Denny’s unique genealogy makes her the first direct descendant ever discovered of two different groups of early humans. While NIH didn’t directly support this research, the sequencing of the Neanderthal genome provided an essential resource.

As exciting as these breakthroughs are, they only scratch the surface of ongoing progress in biomedical research. Every field of science is generating compelling breakthroughs filled with hope and the promise to improve the lives of millions of Americans. So let’s get started with 2019 and finish out this decade with more truly amazing science!

Reference:

[1] “2018 Breakthrough of the Year,” Science, 21 December 2018.

NIH Support: These breakthroughs represent the culmination of years of research involving many investigators and the support of multiple NIH institutes.


Using Frogs to Tackle Kidney Problems

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Cilia

Credit: Vanja Krneta-Stankic and Rachel K. Miller, University of Texas Health Science Center at Houston

Many human cells are adorned with hair-like projections called cilia. Scientists now realize that these specialized structures play many important roles throughout the body, including directing or sensing various signals such as fluid flow. Their improper function has been linked to a wide range of health conditions, such as kidney disease, scoliosis, and obesity.

Studying cilia in people can be pretty challenging. It’s less tricky in a commonly used model organism: Xenopus laevis, or the African clawed frog. This image highlights a healthy patch of motile cilia (yellow) on embryonic skin cells (red) of Xenopus laevis. The cilia found in humans and all other vertebrates are built from essentially the same elongated structures known as microtubules. That’s why researchers can learn a lot about human cilia by studying frogs.


Cool Videos: A Biological Fireworks Display

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Let’s kick off the Fourth of July weekend with some biological fireworks! While we’ve added a few pyrotechnic sound effects just for fun, what you see in this video is the product of some serious research. Using a specialized microscope equipped with a time-lapse camera to image fluorescence-tagged proteins in real-time, an NIH-funded team has captured a critical step in the process of cell division, or mitosis: how filaments called microtubules (red) form new branches (green) and fan out to form mitotic spindles.

In this particular experimental system, the team led by Sabine Petry at Princeton University, Princeton, NJ, studies the dynamics of microtubules in a cell-free extract of cytoplasm taken from the egg of an African clawed frog (Xenopus laevis). Petry’s ultimate goal is to learn how to build mitotic spindles, molecule by molecule, in the lab. Such an achievement would mark a major step forward in understanding the complicated mechanics of cell division, which, when disrupted, can cause cancer and many other health problems.


Snapshots of Life: An Elegant Design

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Collegen

Credit: David Sleboda and Thomas Roberts, Brown University, Providence, RI

Over the past few years, my blog has highlighted winners from the annual BioArt contest sponsored by the Federation of American Societies for Experimental Biology (FASEB). So, let’s keep a good thing going with one of the amazing scientific images that captured top honors in FASEB’s latest competition: a scanning electron micrograph of the hamstring muscle of a bullfrog.

That’s right, a bullfrog, For decades, researchers have used the American bullfrog, Rana catesbeiana, as a model for studying the physiology and biomechanics of skeletal muscles. My own early work with electron microscopy, as a student at Yale in the 1970s, was devoted to producing images from this very tissue. Thanks to its disproportionately large skeletal muscles, this common amphibian has played a critical role in helping to build the knowledge base for understanding how these muscles work in other organisms, including humans.

Revealed in this picture is the intricate matrix of connective tissue that holds together the frog’s hamstring muscle, with the muscle fibers themselves having been digested away with chemicals. And running diagonally, from lower left to upper right, you can see a band of fibrils made up of a key structural protein called collagen.


Cool Videos: Fireworks under a Microscope

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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 [1].