It has been known for some years that naturally occurring mutations in the gene which controls myostatin results in double-muscling in cattle, dogs and even humans. Many in the body building community believe that blocking myostatin is a shortcut to the Arnold Schwarzenegger body.
The flipside is that producing too much myostatin has been linked with muscle wasting conditions such as HIV-AIDS, starvation and now, Type 2 diabetes.
Hittel believes this may be due to a pre-diabetic condition known as insulin resistance that "tricks" the muscles into thinking the body is starving despite the fact that blood sugar levels are skyrocketing.
"When that happens, the body reverses muscle production using myostatin," says Hittel. "This is particularly worrisome because losing muscle mass further erodes your ability to control your blood sugar with exercise."
One of the tell-tale signs of the transition between insulin resistance and full-blown Type 2 diabetes is a loss of muscle mass.
"Losing muscle mass makes sense from an evolutionary perspective since having large muscles during famine puts you at a serious risk for starvation," explains Hittel. "Unfortunately, this survival mechanism has left us ill-equipped to deal with a Western lifestyle-lots of calories, little exercise-and it has laid the groundwork for the current epidemic of Type 2 diabetes."
"The goal of my research is to understand how obesity, diet and exercise influence our metabolism and interact with our genome. This research sheds some light on an important part of the puzzle."
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"This finding is important because the increased surface area may accelerate the regeneration process following an accident," Li said.
The scaffolds are designed specifically to regenerate a portion of a nerve cell called the axon, a long fiber attached to the cell body that transmits signals. Fast regeneration is essential to prevent the atrophy of muscles and organs connected to severed nerves.
The researchers also discovered that the polymer tubes contain pores that are ideal for supplying nutrients to growing nerve cells and removing waste products from the cells.
Images of the polymer-coated sugar strands were taken using a scanning electron microscope. Another instrument, called an atomic force microscope, was used to obtain images of the hollow tubes and pores in the walls of the tubules. Other images using fluorescent dyes revealed the nerve cell alignment along the tubes.
The work was done using cell cultures in petri dishes, but ongoing work focuses on implanting the scaffolds in animals.
The method for creating the scaffolds is relatively simple and inexpensive and does not require elaborate laboratory equipment, Shi said.
"This is low-tech," he said. "We used the same kind of sugar found in candy and a cheap polymer to make samples of these scaffolds for a few dollars. The process easily lends itself to mass production. It is a unique idea, and the simplicity and efficiency of this technology distinguish it from other approaches for nerve repair."
A provisional patent application on the material has been filed.
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