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2009-09-10 12:27:41 | Weblog
[SN Today] from [ScienceNews]

[SN Today > for Kids]
FOR KIDS: Making good, brown fat
Researchers find a way to make energy-burning fat out of other cells

By Stephen Ornes
Web edition : Wednesday, September 9th, 2009

Energy-burning fatThe energy-burning brown fat cells shown here were made by the skin cells of mice. Green dots are oil droplets, red dots are mitochondria and each blue sphere is the nucleus of a cell. Shingo Kajimura Not all fats are created equal: There’s white fat, which stores energy. There’s also another kind of human body fat that actually burns energy and heats up. Babies have this kind of fat, and earlier this year, scientists found that adults have it too. Called brown fat, this substance is stored mainly in the upper body.

According to a new study, it may be possible to make brown fat out of other kinds of cells in the body, such as skin cells. A team of researchers, led by Bruce Spiegelman of the Dana Farber Cancer Institute and Harvard Medical School in Boston, Mass., made brown fat tissue from the skin cells of mice and mouse myoblasts. (A myoblast is a cell that will develop into muscle.)

Because brown fat can burn excess energy, researchers hope it may be used to treat obesity and diabetes. Obesity, which is the condition of being overweight, can lead to other major health problems. Diabetes is a general name given to several different types of illnesses, all of which relate to the body’s ability to manage energy.

In order to make the brown fat cells, Spiegelman and his team started with mouse myoblasts and focused on two proteins. Proteins are the cell’s building blocks and help the cell do its job. The researchers knew that a protein called PRDM16 played some part in converting a myoblast into a brown fat cell, but they had a problem. When they tricked the cell into making more of the protein in a petri dish, nothing changed, and the myoblast cells only formed more myoblasts.

So the scientists looked at another protein, called C/EBP-beta. Just like the first protein, this protein did nothing on its own. But when the scientists added both proteins to the myoblast, the cell created both myoblasts and brown fat cells. They had discovered that the two proteins have to work together.

Even though they were grown in a lab, from other cells, they burn energy similar to normal brown fat cells. “They certainly look like they are brown adipose tissue,” meaning brown fat tissue, Spiegelman says.

There was a difference, however. Normal brown fat cells are able to regulate their energy-burning activity so the human body doesn’t get too hot. The new lab-grown cells, however, are always running on high, which means they’re burning as much energy as possible—which could cause a fever in a person.

The new technique could be used in a number of different ways to help people, says Spiegelman. For example, scientists could remove cells from an obese person, change the cells so they produce brown fat, and return them to the body. Once these altered cells are back in the body, they can produce more brown fat, which would burn energy. Another method may involve injecting an obese person with a compound that could boost his or her production of brown fat cells.

Right now, it’s too early to say whether or not these new brown fat cells will be able to help a person with a weight problem—but the early results are promising.


POWER WORDS (adapted from the Yahoo! Kids Dictionary)

adipose tissue: fat

embryo: An organism in its early stages of development, before birth or hatching

mitochondria: a small organelle, or part of a cell, that converts energy from food into energy that the cell can use

myoblast: An undifferentiated cell in an embryo that is a precursor of a muscle cell.

nucleus: A large structure enclosed in a membrane within a living cell. The nucleus contains the cell's hereditary material and controls its metabolism, growth, and reproduction.

proteins: Molecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances that are necessary for the proper functioning of an organism


[SN Tday > for Kids]
FOR KIDS: Worm glue
A glue similar to the one made by sandcastle worms may one day paste together bones in the human body

By Stephen Ornes
Web edition : Wednesday, September 9th, 2009

{Worm glue
This sandcastle worm lives in the laboratory where scientists can study it. The worm built its house in the lab from small white beads instead of bits of shell and sand. Scientists have created a glue similar to the worm’s glue that may one day be used in bone surgery.
Russell Stewart}

Scientists often look to the natural world for inspiration and ideas. Now, we may be able to thank an unusual worm for a new kind of superglue.

At the University of Utah in Salt Lake City, scientists have created a powerful adhesive that works underwater and hardens quickly, which means it may be useful inside the human body. Most glues don’t work well inside the body, where everything is wet. When surgeons operate on a person to repair broken bones, for example, they may be able to use the new glue to hold the bones together.

The Utah scientists were inspired to make the new glue by a little sea animal called the sandcastle worm. It lives on the coast in an area between the water levels for high and low tides. During high tide, their homes are underwater; when the tide goes out, their homes are left high and dry.

This sea creature gets its name from its house. A sandcastle worm builds its own house by collecting grains of sand, broken shells and other debris and stacking these bits all around. The worm also produces a glue that is used to stick all these pieces together, forming a solid tube. The worm’s glue hardens underwater in less than 30 seconds, and within a few hours the glue gets tough like leather.

Russell Stewart, one of the scientists who worked on the new glue, says that in the same way the sandcastle worm glues together grains of sand, surgeons may be able to glue together broken bones. The worm “literally glues skeletons together underwater, so we thought it would be a good model for wet surgery,” he says.

Stewart, who is a bioengineer at the University of Utah in Salt Lake City, and his colleagues set out to understand the worm’s adhesive, so they could then make their own. First, they studied the sandcastle worm’s glue in the laboratory. They found many proteins, which are tiny molecules that are the construction material of most living things. The researchers learned which proteins give the glue its super-sticking power by studying the proteins’ structures. Half the proteins had strong positive or negative electric charges. Positive and negative charges are attracted to each other and stick together, and this helped make the glue extra sticky.

Once they identified and understood the proteins, the scientists made their own version of the glue in the laboratory. They tested their creation and found that it worked underwater—and was about twice as strong as the worm glue. Further tests showed that the glue isn’t poisonous to human cells.

At the end of the experiment, the scientists had invented a new superstrong glue that worked underwater and was not toxic, which means it didn’t cause harm. These three qualities—strong, working underwater, nontoxic—could make the glue an important part of surgeries in the future. Plus, researchers are now looking at ways to make the glue able to dissolve, which means that over time, as the bones healed, the glue would disappear.

Stewart and his team may have found a new way to help bones heal—all because of a funny little worm on the beach.


POWER WORDS (adapted from Yahoo! Kids dictionary)

cell: The smallest structural unit of an organism that is capable of independent functioning. It consists of one or more nuclei, cytoplasm, and various organelles, all surrounded by a cell membrane.

dissolve: To become liquid or to disappear.

electric charge: The property of matter responsible for all electric phenomena. It occurs in two forms, negative and positive.

proteins: Molecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances that are necessary for the proper functioning of an organism.

toxic: Of, relating to, or caused by poison.

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