Tag: Cellular Imaging

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Cool Image: Tracing Proteins in Action

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Bright amorphous loops

These bright, amorphous loops represent a never-before-seen glimpse at how proteins that play a key role in cell duplication are themselves duplicated. Credit: Sue Jaspersen, Zulin Yu and Jay Unruh, Stowers Institute for Medical Research.

Looking like necklaces stacked on a dresser, these bright, amorphous loops show the outlines of yeast proteins that make up the spindle pole, a cellular component found in organisms as diverse as yeast and humans. Each cell starts with a single spindle pole, which must somehow duplicate to form the pair that works together to pull matching chromosomes apart during cell division. Scientists don’t completely understand how this duplication occurs, but they do know that errors in spindle pole copying can lead to a number of health conditions, including cancer. Continue reading “Cool Image: Tracing Proteins in Action”

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Scientists Shine Light on What Triggers REM Sleep

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Illustration of a brain.
While studying how the brain controls REM sleep, researchers focused on areas abbreviated LDT and PPT in the mouse brainstem. This illustration shows where these two areas are located in the human brain. Credit: Wikimedia Commons. View larger image

Has the “spring forward” time change left you feeling drowsy? While researchers can’t give you back your lost ZZZs, they are unraveling a long-standing mystery about sleep. Their work will advance the scientific understanding of the process and could improve ways to foster natural sleep patterns in people with sleep disorders.

Working at Massachusetts General Hospital and MIT, Christa Van Dort, Matthew Wilson, and Emery Brown focused on the stage of sleep known as REM. Our most vivid dreams occur during this period, as do rapid eye movements, for which the state is named. Many scientists also believe REM is crucial for learning and memory.

REM occurs several times throughout the night, interspersed with other sleep states collectively called non-REM sleep. Although REM is clearly necessary—it occurs in all land mammals and birds—researchers don’t really know why. They also don’t understand how the brain turns REM on and off.

Continue reading “Scientists Shine Light on What Triggers REM Sleep”
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Unprecedented Views of HIV

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Visualizations can give scientists unprecedented views of complex biological processes. Here’s a look at two new ones that shed light on how HIV enters host cells.

Animation of HIV’s Entry Into Host Cells

Screen shot of the video
This video animation of HIV’s entry into a human immune cell is the first one released in Janet Iwasa’s current project to visualize the virus’ life cycle. As they’re completed, the animations will be posted at http://scienceofhiv.org Exit icon.

We previously introduced you to Janet Iwasa, a molecular animator who’s visualized complex biological processes such as cells ingesting materials and proteins being transported across a cell membrane. She has now released several animations from her current project of visualizing HIV’s life cycle Exit icon. The one featured here shows the virus’ entry into a human immune cell.

“Janet’s animations add great value by helping us consider how complex interactions between viruses and their host cells actually occur in time and space,” says Wes Sundquist, who directs the Center for the Structural Biology of Cellular Host Elements in Egress, Trafficking, and Assembly of HIV Exit icon at the University of Utah. “By showing us how different steps in viral replication must be linked together, the animations suggest hypotheses that hadn’t yet occurred to us.” Continue reading “Unprecedented Views of HIV”

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Zinc’s Role in Healthy Fertilization

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Screen shot of the video
Fluorescent sensors at the cell surface show zinc-rich packages being released from the egg during fertilization. Credit: Northwestern Visualization.

Whether aiding in early growth and development, ensuring a healthy nervous system or guarding the body from illness, zinc plays an important role in the human body.

Husband-and-wife team, Thomas O’Halloran Exit icon and Teresa Woodruff, plus other researchers at Northwestern University, evaluated the role that zinc plays in healthy fertilization Exit icon. The study revealed how mouse eggs gather and release billions of zinc atoms at once in events called zinc sparks. These fluxes in zinc concentration are essential in regulating the biochemical processes that facilitate the egg-to-embryo transition.

The scientists developed a series of techniques to determine the amount and location of zinc atoms during an egg cell’s maturation and fertilization as well as in the following two hours. Special imaging methods allowed the researchers to also visualize the movement of zinc sparks in three dimensions. Continue reading “Zinc’s Role in Healthy Fertilization”

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A Bright New Method for Rapidly Screening Cancer Drugs

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Illustration of red, green and blue fluorescent proteins.
Chemists have devised a new approach to screening cancer drugs that uses gold nanoparticles with red, green and blue outputs provided by fluorescent proteins. Credit: University of Massachusetts Amherst.

Scientists may screen billions of chemical compounds before uncovering the few that effectively treat a disease. But identifying compounds that work is just the first step toward developing a new therapy. Scientists then have to determine exactly how those compounds function.

Different cancer therapies attack cancer cells in distinct ways. For example, some drugs kill cancer cells by causing their outer membranes to rapidly rupture in a process known as necrosis. Others cause more subtle changes to cell membranes, which result in a type of programmed cell death known as apoptosis.

If researchers could distinguish the membrane alterations of chemically treated cancer cells, they could quickly determine how that chemical compound brings about the cells’ death. A new sensor developed by a research team led by Vincent Rotello of the University of Massachusetts Amherst can make these distinctions in minutes. Continue reading “A Bright New Method for Rapidly Screening Cancer Drugs”

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Illuminating Biology

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This time of year, lights brighten our homes and add sparkle to our holidays. Year-round, scientists funded by the National Institutes of Health use light to illuminate important biological processes, from the inner workings of cells to the complex activity of the brain. Here’s a look at just a few of the ways new light-based tools have deepened our understanding of living systems and set the stage for future medical advances.

RSV infected cell
A new fluorescent probe shows viral RNA (red) in an RSV-infected cell. Credit: Eric Alonas and Philip Santangelo, Georgia Institute of Technology and Emory University.

Visualizing Viral Activity

What looks like a colorful pattern produced as light enters a kaleidoscope is an image of a cell infected with respiratory syncytial virus (RSV) lit up by a new fluorescent probe called MTRIPS (multiply labeled tetravalent RNA imaging probes).

Although relatively harmless in most children, RSV can lead to bronchitis and pneumonia in others. Philip Santangelo of the Georgia Institute of Technology and Emory University, along with colleagues nationwide, used MTRIPS to gain a closer look at the life cycle of this virus.

Once introduced into RSV-infected cells, MTRIPS latched onto the genetic material of individual viral particles (in the image, red), making them glow. This enabled the researchers to follow the entry, assembly and replication of RSV inside the living cells. Continue reading “Illuminating Biology”

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Field Focus: Bringing Biology Into Sharper View with New Microscopy Techniques

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Composite image of mitochondria in a cell
In this composite image of mitochondria in a cell, the left panel shows a conventional optical microscopy image, the middle panel shows a three-dimensional (3-D) STORM image with color indicating depth, and the right panel shows a cross-section of the 3-D STORM image. Credit: Xiaowei Zhuang laboratory, Howard Hughes Medical Institute, Harvard University. View larger image.

Much as a photographer brings distant objects into focus with a telephoto lens, scientists can now see previously indistinct cellular components as small as a few billionths of a meter (nanometers). By overcoming some of the limitations of conventional optical microscopy, a set of techniques known as super-resolution fluorescence microscopy has changed once-blurry images of the nanoworld into well-resolved portraits of cellular architecture, with details never seen before in biology. Reflecting its importance, super-resolution microscopy was recognized with the 2014 Nobel Prize in chemistry.

Using the new techniques, scientists can observe processes in living cells across space and time and study the movements, interactions and roles of individual molecules. For instance, they can identify and track the proteins that allow a virus to invade a cell or those that enable tumor cells to migrate to distant parts of the body in metastatic cancer. The ability to analyze individual molecules, rather than collections of molecules, allows scientists to answer longstanding questions about cellular mechanisms and behavior, such as how cells move along a surface or how certain proteins interact with DNA to regulate gene activity. Continue reading “Field Focus: Bringing Biology Into Sharper View with New Microscopy Techniques”

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Stem Cells Do Geometry

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Human embryonic cells
As seen under a microscope, human embryonic cells (colored dots) confined to circles measuring 1 millimeter across start to specialize and form distinct layers similar to those seen in early development. Credit: Aryeh Warmflash, Rockefeller University. View larger image

Each fluorescent point of light making up the multicolored rings in this image is an individual human embryonic cell in the early stages of development. Scientists seeking to understand the molecular cues responsible for early embryonic patterning found that human embryonic cells confined to areas of precisely controlled size and shape begin to specialize, migrate and organize into distinct layers just as they would under natural conditions.

Read the Inside Life Science article to learn more about this research, which has opened a new window for studying early development and could advance efforts aimed at using human stem cells to replace diseased cells and regenerate lost or injured body parts.

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Steering Cells Down the Right Path

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In these time-lapse videos (no longer available) of 60 images taken over an hour, cell receptors move around the cell surface in search of the missing signal that will tell the cell where to go (top video). Once the receptors locate the signal (bottom video), they stay put in the region of the cell membrane that is closest to the signal. Credit: David Sherwood, Duke University.

Even traveling cells need help with directions. In fact, it’s crucial. For processes such as wound healing and organ development to take place, cells must be able to efficiently move throughout organisms. Receptor proteins on a cell’s surface rely on navigational signals from molecules called netrins to point them in the right direction.

The receptors don’t just sit around waiting for a signal. Studying the simple worm C. elegans, David Sherwood Exit icon and his research team at Duke University discovered that in the absence of netrin, the receptors rapidly cluster and reassemble in different areas of the cell’s membrane. When the receptors finally detect a netrin signal, they stabilize and correctly orient the cell. The finding might point to new ways to interfere with cells’ built-in navigation systems to hamper cell migration in metastatic cancer or encourage the regrowth of damaged cells in neurodegenerative diseases such as Parkinson’s.

This research was funded in part by NIH under grants R01GM100083 and P40OD010440.

Learn more:
Duke University News Release Exit icon

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Nobel Prize for Powerful Microscopy Technology

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Fibroblasts
The cells shown here are fibroblasts, one of the most common cells in mammalian connective tissue. These particular cells were taken from a mouse. Scientists used them to test the power of a new microscopy technique that offers vivid views of the inside of a cell. The DNA within the nucleus (blue), mitochondria (green) and cellular skeleton (red) is clearly visible. Credit: Dylan Burnette and Jennifer Lippincott-Schwartz, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health.

William E. Moerner was at a conference in Brazil when he learned he’d be getting a Nobel Prize in chemistry. “I was incredibly excited and thrilled,” he said of his initial reaction.

An NIGMS grantee at Stanford University, Moerner received the honor for his role in achieving what was once thought impossible—developing super-resolution fluorescence microscopy, which is so powerful it allows researchers to see and track individual molecules in living organisms in real time.

Nobel recipients usually learn of the prize via a phone call from Stockholm, Sweden, in early October. For those in the United States, the call typically comes between 2:30 a.m. and 5:45 a.m.

Every year, the NIGMS communications office prepares for the Nobel Prize announcements in physiology or medicine and chemistry, the categories in which our grantees are most likely to be recognized. If the Institute played a significant role in funding the prize-winning research, we work quickly to provide information and context to reporters covering the story on tight deadlines. We issue a statement, identify an in-house expert on the research and arrange interviews with reporters. It’s all to help get the word out about the research and the taxpayers’ role in supporting it.

This year’s in-house expert, Cathy Lewis, shared her thoughts on the prize to Moerner in an NIGMS Feedback Loop post. You can also read this year’s statement and see a full list of NIGMS-supported Nobel laureates.