Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Major Breakthrough in Early Detection and Prevention of AMD

17.06.2009
A team of researchers led by Dr. Jayakrishna Ambati at the University of Kentucky has discovered a biological marker for neovascular age-related macular degeneration (AMD), the leading cause of blindness in older adults.

The marker, a receptor known as CCR3, shows strong potential as a means for both the early detection of the disease and for preventive treatment. The findings were reported in an article published online Sunday by the prestigious journal Nature.

"This is a major paradigm shift in macular degeneration research," said Ambati, a professor of physiology, professor and vice-chair of ophthalmology and visual sciences, and the Dr. E. Vernon and Eloise C. Smith Endowed Chair in Macular Degeneration at the UK College of Medicine.

"With CCR3, we have for the first time found a unique molecular signature for the disease. This brings us closer than we have ever been to developing a clinical diagnostic tool to discover and treat the disease early, before vision is lost."

Neovascular (or "wet-type") macular degeneration is caused by choroidal neovascularization (CNV) – the invasive growth of new blood vessels in the thin vascular layer that provides nourishment and oxygen to the eye. Central vision loss occurs when these abnormal blood vessels invade the retina, the light-sensitive tissue that lines the inner surface of the eyeball.

"Once the vessels invade the retina, the horse has already left the barn," Ambati said. "At that point, drugs can slow the process, but irreparable damage has often already been done. This is why finding a means for early detection and intervention is so important."

Drs. Atsunobu Takeda, Judit Z. Baffi, Mark E. Kleinman, Won Gil Cho and other researchers in the Ambati laboratory discovered that CCR3 – a molecule also implicated in inflammatory processes – is expressed on the surface of CNV vessels in humans but is absent from normal vascular tissue.

“CCR3 chemokine receptor is known to be a key player in the allergic inflammation process, but Dr. Ambati’s studies have now identified CCR3 as a key marker of the CNV process involved in AMD. If researchers can determine why CCR3 is expressed in the CNV of AMD patients, they could further understand AMD disease progression,” said Dr. Grace L. Shen, director of the ocular immunology and inflammation program at the National Eye Institute.

Ambati's research team was able to detect these same abnormal blood vessels in the living eyes of mice by attaching anti-CCR3 antibodies to tiny semiconductor nanocrystals called "quantum dots" and injecting these into the mice. The antibodies cause the quantum dots to attach to CCR3 on the surface of the abnormal blood vessels, making them visible with conventional ocular angiography techniques, even before they have penetrated the retina. This was not possible before.

“This is an exciting discovery for the millions of people at risk of developing wet macular degeneration, because this new imaging technology introduces the possibility of detecting pathological neovascularization before retinal damage and vision loss occur,” said Dr. Stephen J. Ryan, professor of ophthalmology at the University of Southern California and member of the National Academy of Sciences’ Institute of Medicine.

The research team discovered that CCR3 not only provides a unique signature for CNV, but the gene actively promotes the growth of these abnormal blood vessels in the eye. Thus the same anti-CCR3 antibodies used to detect CNV could potentially be useful as a clinical treatment to prevent macular degeneration.

The early results look promising. Treatment with anti-CCR3 antibodies reduced CNV in mice by about 70 percent, as opposed to 60 percent with VEGF-based treatments currently in clinical use. Ambati says Phase I clinical trials are not far off.

“The identification of CCR3 on the endothelial cells of CNV in human AMD is a major breakthrough," said Dr. Patricia A. D’Amore, professor of ophthalmology at Harvard Medical School. "The preclinical data is very exciting and suggests that targeting CCR3 may be the basis of the next generation of targeted anti-angiogenesis therapy for wet AMD.”

Ambati's paper, "CCR3 is a target for age-related macular degeneration diagnosis and therapy," was released online today and will be printed in an upcoming issue of Nature.

Age-related macular degeneration is the leading cause of blindness in older adults in the industrialized world, affecting some 10-12 million people in the United States – more than all cancers combined and about twice as many as Alzheimer's disease. Nationwide, about 250,000 new cases of CNV are reported annually.

This work was supported by research grants from the National Eye Institute of the National Institutes of Health and an unrestricted grant from Research to Prevent Blindness. Dr. Ambati is also supported by a Doris Duke Distinguished Clinical Scientist Award and the Burroughs Wellcome Translational Research Clinical Scientist Award. Key collaborators in the study include Drs. Marc Rothenberg (Cincinnati Children’s Hospital), M. Elizabeth Hartnett (UNC-Chapel Hill), Craig Gerard (Children’s Hospital, Boston), Salvatore Grisanti (University of Luebeck), and Justine Smith (Casey Eye Institute).

Keith Hautala | EurekAlert!
Further information:
http://www.uky.edu

More articles from Health and Medicine:

nachricht Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin

nachricht Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>