Nav: Home

Inhibiting post-translational modifications may lower oxidative stress in the aging eye

March 11, 2019

Retinal pigment epithelial (RPE) cells are a pigmented cells present in a monolayer outside the retinal. These cells are essential for absorbing scattered light in the eye and maintain visual function. As a person ages, these cells can die without, causing age-related macular degeneration (AMD), a blinding eye disease that affects more than 30 million people worldwide. Oxidative stress-induced RPE cell senescence is considered as one the greatest risk factors contributing to the onset of AMD. Other factors include hereditary factors which modulate inflammation.

Most cellular processes are regulated by the expression of genes into specific proteins. Some proteins (such as SUMO proteins) can modify existing proteins to trigger cellular processes. Cell senescence is such a process and this is believed to be regulated by SUMOylation - an essential post-translational modification reaction in vertebrates - which results in the conjugation of SUMO proteins to target proteins involved in the process.

A team of researchers from the Zhongshan Ophthalmology Center, Guangzhou, China, led by Dr. David W. Li and Dr. Lili Gong, studied SUMOylation processes in mouse retinae in an effort to investigate cell senescence in RPE cells. The researchers found decreased SUMO ligase expression in aging mouse retina samples and in senescent RPE cells, a finding which indicates reduced global protein SUMOylation levels. Interestingly, the researchers also learned that the localized distribution of SUMO ligases, such as E1 enzyme UBA2, E2 enzyme UBC9, was dramatically changed during the oxidative stress-induced RPE cell senescence. "This altered distribution of the major SUMO machinery suggests that the SUMOylation substrates may be altered and both loss of SUMOylation and an increase in new SUMOylation products may occur during cell senescence," says Dr. Lili. The researchers believe that in addition to decreased SUMOylation levels, SUMOylation targets in senescent cells are likely different from those in young cells and this difference may be accounted for by the spatial regulation of SUMO ligases within RPE cells.

Additionally, the researchers investigated the inhibition of SUMOylation with two small molecules and ML792 (that targets the SUMO E1 enzyme). Their results indicate that ML792 treatment alleviated the expression of senescence associated secretory phenotype (SASP) genes - or in other words, the aged cell variants - in RPE cells, as several proinflammatory factor was observed to be down-regulated by ML972 treatment. "This is the first report that shows that inhibition of SUMOylation has reduced SASP, expression", notes Dr. Lili. Their research can grow the understanding of AMD pathogenesis and lead to new avenues for treatment. Dr. Lili adds that "it is very intriguing considering the effects of SASP factors in compromising RPE cell barrier functions and resulting in immune cell invasion, which contributes to the severity of retina degeneration and AMD pathogenesis."
To obtain the article please visit, please visit:

Bentham Science Publishers

Related Proteins Articles:

Discovering, counting, cataloguing proteins
Scientists describe a well-defined mitochondrial proteome in baker's yeast.
Interrogating proteins
Scientists from the University of Bristol have designed a new protein structure, and are using it to understand how protein structures are stabilized.
Ancient proteins studied in detail
How did protein interactions arise and how have they developed?
What can we learn from dinosaur proteins?
Researchers recently confirmed it is possible to extract proteins from 80-million-year-old dinosaur bones.
Relocation of proteins with a new nanobody tool
Researchers at the Biozentrum of the University of Basel have developed a new method by which proteins can be transported to a new location in a cell.
Proteins that can take the heat
Ancient proteins may offer clues on how to engineer proteins that can withstand the high temperatures required in industrial applications, according to new research published in the Proceedings of the National Academy of Sciences.
Designer proteins fold DNA
Florian Praetorius and Professor Hendrik Dietz of the Technical University of Munich have developed a new method that can be used to construct custom hybrid structures using DNA and proteins.
The proteins that domesticated our genomes
EPFL scientists have carried out a genomic and evolutionary study of a large and enigmatic family of human proteins, to demonstrate that it is responsible for harnessing the millions of transposable elements in the human genome.
Rare proteins collapse earlier
Some organisms are able to survive in hot springs, while others can only live at mild temperatures because their proteins aren't able to withstand such extreme heat.
How proteins reshape cell membranes
Small 'bubbles' frequently form on membranes of cells and are taken up into their interior.

Related Proteins Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".