Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Eye proteins have germ-killing power, could lead to new antimicrobial drugs, study finds

25.09.2012
When it comes to germ-busting power, the eyes have it, according to a discovery by UC Berkeley researchers that could lead to new, inexpensive antimicrobial drugs.

A team of UC Berkeley vision scientists has found that small fragments of keratin protein in the eye play a key role in warding off pathogens. The researchers also put synthetic versions of these keratin fragments to the test against an array of nasty pathogens.

These synthetic molecules effectively zapped bacteria that can lead to flesh-eating disease and strep throat (Streptococcus pyogenes), diarrhea (Escherichia coli), staph infections (Staphylococcus aureus) and cystic fibrosis lung infections (Pseudomonas aeruginosa).

The findings, to be published in the October issue of the Journal of Clinical Investigation, could lead to a powerful new weapon in the battle against disease-causing invaders. These keratin fragments are relatively easy to manufacture, making them good candidates for low-cost therapeutics, the study authors 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,” said the study’s principal investigator, Suzanne Fleiszig, a professor at UC Berkeley’s School of Optometry who specializes in infectious diseases and microbiology. “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.”

These new small proteins in the study were derived from cytokeratin 6A, one of the filament proteins that connect to form a mesh throughout the cytoplasm of epithelial cells.

“We used to think that cytokeratins were primarily structural proteins, but our study shows that these fragments of keratin also have microbe-fighting capabilities,” said study lead author Connie Tam, an assistant research scientist in Fleiszig’s lab. “Cytokeratin 6A can be found in the epithelial cells of the human cornea as well as in skin, hair and nails. These are all areas of the body that are constantly exposed to microbes, so it makes sense that they would be part of the body’s defense.”

In a commentary published alongside the study, Michael Zasloff, professor of surgery and pediatrics at Georgetown University’s School of Medicine, said these “keratin-derived antimicrobial peptides appear to be exciting new biocompatible candidates for development as human anti-infective therapeutics.”

The researchers in Fleiszig’s lab came upon cytokeratin 6A in their efforts to solve the mystery behind the eye’s remarkable resilience to infection. They noticed that the surface of the eye, unlike other surfaces of the body, did not have bacteria living on it, and that corneal tissue could handily wipe out a barrage of pathogens in lab culture experiments.

“It is very difficult to infect the cornea of a healthy eye,” said Fleiszig. “We’ve even used tissue paper to damage the eye’s surface cells and then plastered them with bacteria, and still had trouble getting bacteria to enter the cornea. So we proposed that maybe there were antimicrobial factors that are unique to the eye.”

In the hunt for this mystery compound, the researchers cultured human corneal epithelial cells and exposed them to the P. aeruginosa bacteria. They used mass spectrometry to sort out which peptides were most active in fighting off the bacteria. Cytokeratin 6A-derived peptides emerged the winners, and surprisingly, peptide fragments as short as 10 amino acids were effective.

To confirm that they got the right protein, the researchers used gene-silencing techniques to reduce the expression of cytokeratin 6A in the cornea of mice. With a key defense disabled, the amount of bacteria that adhered to the corneas increased fivefold.

Tests showed that cytokeratin 6A-derived fragments could quickly kill bacteria in water and in a saline solution, showing that the salt contained in human tears would not dilute the protein’s effectiveness. Other experiments indicated that cytokeratin 6A fragments prevented the bacteria from attacking epithelial cells, and that the proteins cause bacterial membranes to leak, killing the pathogen within minutes.

The researchers noted that further research could reveal numerous different keratin fragments in the body’s innate defense system.

“Keratins may represent a novel class of antimicrobials with the potential to be designed to selectively kill specific pathogens,” said Tam.

Other study co-authors from UC Berkeley’s School of Optometry are James Mun, a former UC Berkeley Ph.D. student, and David Evans, a UC Berkeley associate research scientist and a professor of biological and pharmaceutical sciences at Touro University California in Vallejo.

The Bill and Melinda Gates Foundation and the National Institutes of Health provided support for this research.

Sarah Yang | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>