RESE ARCH
The eye is just another place that, if the bacterium can find its way in, will create problems. And if such infections aren’t treated properly, people can lose their vision.” With her new grant, Callegan aims to better understand why Staphylococcus aureus is able to circumvent the body’s ocular defenses and cause blinding infections. Although staphylococcal species share characteristics, Staphylococcus aureus is among the most dangerous for the eye and the body. “The more bacteria that we work with, the more we discover that they’re all very different. Different species have different ways of interacting with the immune response in the body. It’s worth investigating them individually, but if you can pinpoint aspects of these different organisms that are similar, you can target these factors and develop new treatments to fight them,” said Callegan, who is also a professor in the Departments of Ophthalmology and Microbiology and Immunology in the OU College of Medicine. Research reported in this story is supported by the National Eye Institute, a component of the National Institutes of Health, under the award number 1R01 EY032073-01A1. The project has also received support from Presbyterian Health Foundation in Oklahoma City.
This image from the research lab of Jody Summers, Ph.D., shows the choroid of the eye.
OU College of Medicine researcher Jody Summers, Ph.D., a professor in the Department of Cell Biology, recently discovered that one of the body’s regulators of inflammation, a protein called Interleukin-6 (IL-6), plays a role in the development of myopia, thereby becoming a potential target to prevent or slow the condition. Summers published her findings in the influential journal eLife. “The prevalence of myopia is increasing and is predicted to affect half of the world’s population by 2050,” Summers said. “With that increase, there is a greater likelihood that myopia will occur in people at a younger age. In some cases, myopia increases the risk of other serious eye conditions like retinal detachment, glaucoma and macular degeneration. Our study suggests that if we could target IL-6, it may be a means of controlling eyesight.” Myopia typically occurs when the sclera (the white part of the eye) expands, causing the eye to be longer than normal. As a result, the light entering the eye is focused in front of the retina, instead of on the retina, resulting in blurry distance vision. That “defocus” also occurs when people wear glasses or contacts to correct myopia, but have blurry vision when they remove them.
Jody Summers, Ph.D., discovered that a protein called Interleukin-6 plays a role in the onset of myopia.
Researcher Discovers Protein in Development of Nearsightedness
“The increase in IL-6 is triggering a cascade of events that cause the eye to try to correct its size so that it is the right size for its focus,” she said. “Our hypothesis is that IL-6 is playing a positive role in that it detects when the eye is too long and then stimulates subsequent changes in an effort to get the eye to stop growing.”
Millions of people are affected by myopia (nearsightedness), in which they can see close objects clearly, but distance vision is blurred. Glasses, contact lenses or refractive surgery can improve vision, but don’t fix the underlying problem itself. But what if there were a way to address the actual cause of myopia?
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Summers’ main focus for the study was on the choroid — the vascular layer between the retina and sclera — because molecules that could affect scleral growth are likely synthesized in the choroid or pass through it on their way to the sclera. She discovered that just at the moment of “defocus,” there was a rapid increase of IL-6 in the choroid.
The finding is important because once an action like that of IL-6 has been identified, researchers may be able target it with a drug in an effort to control eyesight. Summers is the first researcher to demonstrate the association between IL-6 and eye size. IL-6 is a cytokine, a type of protein that regulates inflammation in the body. It is released by muscle cells during
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