New study represents major breakthrough in macular degeneration

August 6, 2012

University of Kentucky researchers, led by Dr. Jayakrishna Ambati, have made an exciting finding in the "dry" form of age-related macular degeneration known as geographic atrophy (GA). GA is an untreatable condition that causes blindness in millions of individuals due to death of retinal pigmented epithelial cells.

The paper, "ERK1/2 Activation is a in Age-Related Macular Degeneration" appears in the current online issue of the premier journal .

Ambati, professor of physiology, and professor and vice chair of ophthalmology and visual sciences at UK, is a leader in the field of macular degeneration research. Previous research from the Ambati laboratory published in the journal Nature showed that in human eyes with geographic atrophy there is a deficiency of the enzyme DICER1, leading to accumulation of toxic Alu in the retinal pigmented epithelium. Another paper published in the journal Cell showed that when these RNAs build up in the eye they trigger activation of an immune complex known as the NLRP3 inflammasome. In turn, this leads to the production of a molecule known as IL-18, which causes death of retinal pigmented and vision loss by activating a known as MyD88. Importantly, Ambati and colleagues found evidence that activity of the inflammasome, IL-18, and MyD88 were all increased in human eyes with GA. They then showed that blocking any of these components could prevent retinal degeneration in multiple . The researchers are excited that blocking these pathways could herald a new potential therapy for GA, for which there is no approved treatment.

In the current paper, the authors show that Alu RNA, which increases following DICER1 deficit, activates a family of enzymes known as extracellular-signal-regulated kinases (ERK) 1/2. ERK 1/2, which are also known as classical mitogen-activated protein kinases (MAPKs), were found to be increased in the RPE of human eyes with GA and shown to be key mediators of RPE cell death. This work further defines the mechanisms of cell death in human GA and identifies a new therapeutic target for the dry form of AMD.

Explore further: Research represents major breakthrough in macular degeneration

Related Stories

Vision loss slowed by encapsulated cell therapy

April 7, 2011

( -- A phase 2 clinical trial for the treatment of a severe form of age-related macular degeneration called geographic atrophy (GA) has become the first study to show the benefit of a therapy to slow the progression ...

Recommended for you

Mitochondria control stem cell fate

October 27, 2016

What happens in intestinal epithelial cells during a chronic illness? Basic research conducted at the Chair of Nutrition and Immunology at the Technical University of Munich (TUM) addressed this question by generating a new ...

Hormone that controls maturation of fat cells discovered

October 25, 2016

Scientists at the Stanford University School of Medicine have discovered a hormone that controls the first step in the maturation of fat cells. Its actions help explain how high-fat diets, stress and certain steroid medications ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.