All and Mighty Eyes

Eye proteins could lead to inexpensive drugs to fight bacteria

(RxWiki News) The eyes may be sensitive at times, but they are tough. And new research shows that parts of them may be able to combat diseases.

A recently published study that's still in the early stages has found that proteins found in the eye can help fight and kill germs. The proteins come from one of the connecting structures found throughout cells and cytoplasm, a gel-like substance, in the eyeball.

"Wash your hands before touching your eyes."

Researchers from the University of California at Berkeley found small pieces of keratin, proteins that make up the outer layer of skin, hair and nails, in the eye that help ward off germs.

Led by Suzanne Fleiszig, OD, PhD, a professor at UC Berkeley’s School of Optometry who specializes in infectious diseases and microbiology, noticed that germs and bacteria did not live on the surface of the eye unlike other parts of the body.

Researchers used tissue paper to damage the outside cells of the eye and covered them with bacteria. Dr. Fleiszig said they still had trouble getting bacteria to enter the cornea.

The researchers then created human corneal cells and exposed them to bacteria. The synthetic keratin pieces also kill bacteria that cause strep, diarrhea, staph infections and cystic fibrosis lung infections.

Connie Tam, a co-researcher on the study, said that these cytokeratin structures are found in areas of the body that are always exposed to microbes, so "it makes sense that they would be part of the body’s defense.”

They sorted out which of the cells parts fought off bacteria the most and found that the cytokeratin proteins were the best.

To make sure they got the right protein, researchers reduced the cytokeratin protein in the eyes of mice, exposed it to bacteria and found the bacteria increased five-fold.

Tissue from the cornea of the eye can easily wipe out pathogens in lab experiments, they said.

“What’s really exciting is that the keratins in our study are already in the body, so we know that they are not toxic, and that they are biocompatible,” Dr. Fleiszig said in a press release.

"The problem with small, naturally occurring, antimicrobial molecules identified in previous research is that they were either toxic or easily inactivated by concentrations of salt that are normally found in our bodies.”

The protein pieces can also kill bacteria in water and in a saline solution, showing that human tears won't affect how well the protein protects against germs.

They also found that the proteins prevent the bacteria from attacking other cells. The protein also causes the outside of bacteria to leak, thus killing the germ in minutes.

The fragments are pretty easy to create, making them good candidates for low-cost therapeutics, the researchers said.

This is very exciting new research which identifies a novel and natural defense against harmful bacteria," said Chris Quinn, OD, an optometrist with Omni Eye Services and dailyRx Contributing Expert.

"Further development of these research findings may lead to the development of an entirely new way to as prevent eye infections which could lead to blindness.

The Bill and Melinda Gates Foundation and the National Institutes of Health supported the study.

The authors note that they are co-inventors of two patents that include information from their study. The findings will be published in the October issue of the Journal of Clinical Investigation.

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Review Date: 
October 3, 2012