PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Cholesterol buildup links atherosclerosis and macular degeneration

2013-04-02
(Press-News.org) VIDEO: This is video of an examination of the retina of a patient with age-related macular degeneration. The light-colored flecks are cholesterol-rich deposits that have built up under the retina....
Click here for more information.

A new study raises the intriguing possibility that drugs prescribed to lower cholesterol may be effective against macular degeneration, a blinding eye disease.

Researchers at Washington University School of Medicine in St. Louis have found that age-related macular degeneration, the leading cause of vision loss in Americans over 50, shares a common link with atherosclerosis. Both problems have the same underlying defect: the inability to remove a buildup of fat and cholesterol.

The new study is published online in the journal Cell Metabolism.

Working in mice and in human cells, the researchers shed new light on how deposits of cholesterol contribute to macular degeneration and atherosclerosis and even blood vessel growth in some types of cancer.

Patients who have atherosclerosis often are prescribed medications to lower cholesterol and keep arteries clear. This study suggests that some of those same drugs could be evaluated in patients with macular degeneration.

"Based on our findings, we need to investigate whether vision loss caused by macular degeneration could be prevented with cholesterol-lowering eye drops or other medications that might prevent the buildup of lipids beneath the retina," says senior investigator Rajendra S. Apte, MD, PhD.

AUDIO: Researchers at Washington University School of Medicine in St. Louis have found that a particular aging-related mechanism contributes to some seemingly unrelated diseases, and the study raises the possibility that...
Click here for more information.

The new research centers on macrophages, key immune cells that remove cholesterol and fats from tissues. In macular degeneration, the excessive buildup of cholesterol begins to occur as we age, and our macrophages begin to malfunction.

In the "dry" form of age-related macular degeneration, doctors examining the eye can see lipid deposits beneath the retina. As those deposits become larger and more numerous, they slowly begin to destroy the central part of the eye, interfering with the vision needed to read a book or drive a car.

As aging macrophages clear fewer fat deposits beneath the retina, the macrophage cells themselves can become bloated with cholesterol, creating an inflammatory process that leads to the formation of new blood vessels that can cause further damage. Those vessels characterize the later "wet" form of the disease.

"Ultimately, that inflammation creates a toxic mix of things that leads to new blood vessel growth," Apte explains. "Most of the vision loss from 'wet' macular degeneration is the result of bleeding and scar-tissue formation related to abnormal vessel growth."

As part of their research, the scientists identified a protein that macrophages need to clear fats and cholesterol. As mice and humans age, they make less of the protein, and macrophages become less effective at engulfing and removing fat and cholesterol.

Apte, the Paul A. Cibis Distinguished Professor of Ophthalmology and Visual Sciences, and his team found that macrophages, from old mice and in patients with macular degeneration, have inadequate levels of the protein, called ABCA1, which transports cholesterol out of cells. As a result, the old macrophages accumulated high levels of cholesterol and couldn't inhibit the growth of the damaging blood vessels that characterize the "wet" form of the disorder.

But when the researchers treated the macrophages with a substance that helped restore levels of ABCA1, the cells could remove cholesterol more effectively, and the development of new blood vessels was slowed.

"We were able to deliver the drug, called an LXR agonist, in eye drops," says first author Abdoulaye Sene, PhD, a post-doctoral fellow in the Apte lab. "And we found that we could reverse the macular degeneration in the eye of an old mouse. That's exciting because if we could use eye drops to deliver drugs that fight macular degeneration, we could focus therapy only on the eyes, and we likely could limit the side effects of drugs taken orally."

Sene and Apte also say that since macrophages are important in atherosclerosis and in the formation of new blood vessels around certain types of cancerous tumors, the same pathway also might provide a target for more effective therapies for those diseases.

"We have shown that we can reverse the disease cascade in mice by improving macrophage function, either with eye drops or with systemic treatments," Apte says. "Some of the therapies already being used to treat atherosclerosis target this same pathway, so we may be able to modify drugs that already are available and use them to deliver treatment to the eye."



INFORMATION:



By Jim Dryden

Sene A, Khan AA, Cox D, Nakamura REI, Santeford A, Kim BM, Sidhu R, Onken MD, Harbour JW, Haqbi-Levi S, Chowers I, Edwards PA, Baldan A, Parks JS, Ory DS, Apte RS. Impaired cholesterol efflux in senescent macrophages promotes age-related macular degeneration. Cell Metabolism, vol. 17(4), published online April 2, 2013

Funding for this research comes from the National Eye Institute (NEI), the National Heart, Lung and Blood Institute (NHLBI) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH). Other funding was provided by the U.S. Civilian Research and Development Foundation (RSA), a Carl Marshall Reeves and Mildred Almen Reeves Foundation Inc. Award, a Research to Prevent Blindness Inc. Career Development Award, the American Health Assistance Foundation, the Lacy Research Foundation, the Thome Foundation and a Research to Prevent Blindness Inc. unrestricted grant to Washington University.

NIH grant numbers are K08EY016139, R01 EY019287, Vision Core Grant P30EY02687, P01HL049373, R01 HL094525, R01 HL067773 and P60 DK20579, which provides funding for the Metabolomics Facility at the Washington University Diabetes Research Center.

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.



ELSE PRESS RELEASES FROM THIS DATE:

NYSCF scientists develop 3-D stem cell culture technique to better understand Alzheimer's disease

2013-04-02
NEW YORK, NY (March 25, 2013) – A team of researchers at The New York Stem Cell Foundation Research Institute led by Scott Noggle, PhD, Director of the NYSCF Laboratory and the NYSCF – Charles Evans Senior Research Fellow for Alzheimer's Disease, and Michael W. Nestor, PhD, a NYSCF Postdoctoral Research Fellow, has developed a technique to produce three-dimensional cultures of induced pluripotent stem (iPS) cells called embryoid bodies, amenable to live cell imaging and to electrical activity measurement. As reported in their Stem Cell Research study, these cell aggregates ...

Monkey study reveals why middle managers suffer the most stress

2013-04-02
A study by the universities of Manchester and Liverpool observing monkeys has found that those in the middle hierarchy suffer the most social stress. Their work suggests that the source of this stress is social conflict and may help explain studies in humans that have found that middle managers suffer the most stress at work. Katie Edwards from Liverpool's Institute of Integrative Biology spent nearly 600 hours watching female Barbary macaques at Trentham Monkey Forest in Staffordshire. Her research involved monitoring a single female over one day, recording all incidences ...

Scientists provide a more accurate age for the El Sidron cave Neanderthals

2013-04-02
A study has been able to accurately determine the age of the Neanderthal remains found in the El Sidrón cave (Asturias, Spain) for which previous studies had provided inexact measurements. The application of a pre-treatment to reduce contamination by modern carbon has managed to lower the margin of error from 40,000 to just 3,200 years. El Sidrón cave in Asturias (northern Spain) is one of the westernmost Neanderthal sites on the Iberian Peninsula and contains a large amount of this type of remains in addition to the flint tools they used. Now, thanks to the development ...

New clues in the search to rediscover the mysterious Maya Blue formula

2013-04-02
VIDEO: There are new clues in the search to rediscover the mysterious Maya Blue formula. Click here for more information. The recipe and process for preparing Maya Blue, a highly-resistant pigment used for centuries in Mesoamerica, were lost. We know that the ingredients are a plant dye, indigo, and a type of clay known as palygorskite, but scientists do not know how they were 'cooked' and combined together. Now, a team of chemists from the University of Valencia and the Polythecnic ...

LSUHSC research discoveries shed light on common STI

2013-04-02
New Orleans, LA – Research led by David H. Martin, MD, Professor and Chief of Infectious Diseases at LSU Health Sciences Center New Orleans, has found that a common sexually transmitted infection-causing parasite "cultivates" bacteria beneficial to it, changing thinking about which comes first–infection or bacteria. The researchers also discovered a previously unknown species of these bacteria. The research was published ahead of print online in Advance Access in the Journal of Infectious Diseases, and was published online April 2, 2013 in Research Highlights in Nature ...

Sampling of embryonic DNA after IVF without biopsy

2013-04-02
Cambridge, UK, April 2, 2013 – Preimplantation genetic diagnosis (PGD) technologies allow identification of genetic disorders in human preimplantation embryos after in vitro fertilization (IVF) and before the embryo is transferred back to the patient. This technique allows couples with a high-risk of passing on inherited diseases, to increase their chances of having a healthy baby. Despite the theoretical benefits of PGD, clinical outcomes using these technologies vary, possibly because of the need to remove one or more cells from the embryo using biopsy. In a recent ...

Remaining unnoticed for 100 years, a Kyrgyz onion species strikes with its beauty

2013-04-02
Situated at the foothills of the Western Tian-Shan, Kyrgyzstan is home to a diverse range of vascular plants, many of which are endemic and can only be found in very narrowly circumscribed areas. Such is the case for the onion species Allium spathulatum that had long remained undetected in spite of living within the famous Sary-Chelek Nature Reserve. Even in close proximity to the headquarters it remained unnoticed until it was finally described in 1998. The species occurs in the low-altitude forest zone, between 1600 and 1700 m a.s.l., dwelling in river valleys, on open ...

Fast track to mouse modeling

2013-04-02
Scientists use genetically modified laboratory mice to investigate the underlying mechanisms of diseases. These "knockout" mice carry genes or gene regions that are thought to trigger diseases. For laboratories, the knockout technique requires a lot of time and effort. "Scientists start by engineering a genetic defect into embryonic stem cells," explains Prof. Wolfgang Wurst, who carries out research at Technische Universität München (TUM) and Helmholtz Zentrum München. "Then they implant the manipulated stem cells into a mouse embryo." Genetic defects made to order After ...

Reviewing the work of 1 of the greatest beetle collectors: Napoleon's General Dejean

2013-04-02
Two Canadian scientists have undertaken the challenging task to bring up to date the catalogues written by one of the most passionate collectors of beetles, Coleoptera, in the 19th century, Pierre Dejean. Dr. Yves Bousquet and Dr. Patrice Bouchard, who work with the Canadian National Collection of Insects, Arachnids and Nematodes, have now produced a pioneering detailed review of the important nomenclatural and taxonomic data in these rich publications. Two articles analyzing the Coleoptera genera in the second (1833) and third (1836) catalogues of Dejean's collection were ...

Vitamin P as a potential approach for the treatment of damaged motor neurons

2013-04-02
Biologists from the Ruhr-Universität Bochum have explored how to protect neurons that control movements from dying off. In the journal "Molecular and Cellular Neuroscience" they report that the molecule 7,8-Dihydroxyflavone, also known as vitamin P, ensures the survival of motor neurons in culture. It sends the survival signal on another path than the molecule Brain Derived Neurotrophic Factor (BDNF), which was previously considered a candidate for the treatment of motoneuron diseases or after spinal cord damage. "The Brain Derived Neurotrophic Factor only had a limited ...

LAST 30 PRESS RELEASES:

Drones reveal extreme coral mortality after bleaching

New genetic finding uncovers hidden cause of arsenic resistance in acute promyelocytic leukemia

Native habitats hold the key to the much-loved smashed avocado’s future

Using lightning to make ammonia out of thin air

Machine learning potential-driven insights into pH-dependent CO₂ reduction

Physician associates provide safe care for diagnosed patients when directly supervised by a doctor

How game-play with robots can bring out their human side

Asthma: patient expectations influence the course of the disease

UNM physician tests drug that causes nerve tissue to emit light, enabling faster, safer surgery

New study identifies EMP1 as a key driver of pancreatic cancer progression and poor prognosis

XPR1 identified as a key regulator of ovarian cancer growth through autophagy and immune evasion

Flexible, eco-friendly electronic plastic for wearable tech, sensors

Can the Large Hadron Collider snap string theory?

Stuckeman professor’s new book explores ‘socially sustainable’ architecture

Synthetic DNA nanoparticles for gene therapy

New model to find treatments for an aggressive blood cancer

Special issue of Journal of Intensive Medicine analyzes non-invasive respiratory support

T cells take aim at Chikungunya virus

Gantangqing site in southwest China yields 300,000-year-old wooden tools

Forests can’t keep up: Adaptation will lag behind climate change

Sturgeon reintroduction initiative yields promising first-year survival rate

Study: Babies’ poor vision may help organize visual brain pathways

Research reveals Arctic region was permafrost-free when global temperatures were 4.5˚ C higher than today

Novel insights into chromophobe renal cell carcinoma biology and potential therapeutic strategies

A breakthrough in motor safety: AI-powered warning system enhances capability to uncover hidden winding faults

Research teases apart competing transcription organization models

Connect or reject: Extensive rewiring builds binocular vision in the brain

Benefits and risks: informal use of antibiotics to prevent sexually transmitted infections on the rise in key populations in the Netherlands

New molecular tool sheds light on how cancer cells repair telomeres

First large-scale stem cell bank enables worldwide studies on genetic risk for Alzheimer’s disease

[Press-News.org] Cholesterol buildup links atherosclerosis and macular degeneration