Skip to main content

Morphing brain DNA hints at a whole new way to treat Alzheimer’s

Morphing brain DNA hints at a whole new way to treat Alzheimer’s:

Amyloid protein in Alzheimer's disease.
People with Alzheimer’s disease get a build up of a protein in the brain called beta-amyloid.

 By Alice Klein

Brain cells are reshuffling their own DNA. The finding may explain how Alzheimer’s disease develops and pave the way for new treatments using existing HIV drugs.
Most drugs for treating Alzheimer’s disease are designed to clear out clumps of beta-amyloid protein that build up in the brain of people with the condition. But they have had disappointing outcomes in clinical trials so far.
While studying the gene responsible for making beta-amyloid – called APP – Jerold Chun at Sanford Burnham Prebys Medical Discovery Institute in California and his colleagues discovered something strange. The gene appeared to be able to reshuffle its DNA, allowing it to take thousands of different forms.
The team found about 10 times more variants of the APP gene in brain cells from people with Alzheimer’s disease than without. These different forms were able to produce a range of toxic proteins in addition to beta-amyloid.
The finding may explain why Alzheimer’s drugs that specifically target beta-amyloid have had limited success, says Chun. “They may be missing thousands of other toxic products that are a bit different or maybe very different,” he says.

Shapeshifting gene

At the moment, it’s unclear why the APP gene is able to morph into different forms. In healthy people, it may give the brain greater flexibility by letting it produce a wider repertoire of signaling proteins, says Chun.
We also don’t know why the gene seems to shapeshift more in the brains of people with Alzheimer’s disease, says Chun. So far, his team’s research suggests that it is linked to the activity of a group of enzymes called reverse transcriptases.
The same enzymes are already well-known in the context of HIV, as they are responsible for letting the virus insert itself in infected people’s DNA. It’s possible that existing HIV drugs that block these enzymes  – called reverse transcriptase inhibitors – may also be useful for treating Alzheimer’s disease, says Chun.
This idea is supported by the observation that elderly HIV patients who have been on long-term treatment with reverse transcriptase inhibitors seem rarely to develop Alzheimer’s disease. However, clinical trials will be needed to prove it, says Chun.
His team is currently testing the effectiveness of already-available reverse transcriptase inhibitors for HIV in mouse models of Alzheimer’s disease, as well as planning possible future trials in humans. “The great thing about these drugs is that many of them have been used in HIV patients for decades, so we already know they’re safe,” he says.

Comments

Post a Comment

Popular posts from this blog

Home births as safe as hospital births: International study suggests

A large international study led by McMaster University shows that low risk pregnant women who intend to give birth at home have no increased chance of the baby's perinatal or neonatal death compared to other low risk women who intend to give birth in a hospital. The results have been published by  The Lancet 's  EClinicalMedicine  journal. "More women in well-resourced countries are choosing birth at home, but concerns have persisted about their safety," said Eileen Hutton, professor emeritus of obstetrics and gynecology at McMaster, founding director of the McMaster Midwifery Research Centre and first author of the paper. "This research clearly demonstrates the risk is no different when the birth is intended to be at home or in hospital." The study examined the safety of place of birth by reporting on the risk of death at the time of birth or within the first four weeks, and found no clinically important or statistically different risk between home...
Post a Comment
Read more

Dark matter may be older than the Big Bang

Dark matter, which researchers believe make up about 80% of the universe's mass, is one of the most elusive mysteries in modern physics. What exactly it is and how it came to be is a mystery, but a new Johns Hopkins University study now suggests that dark matter may have existed before the Big Bang. The study, published August 7 in  Physical Review Letters , presents a new idea of how dark matter was born and how to identify it with astronomical observations. "The study revealed a new connection between particle physics and astronomy. If dark matter consists of new particles that were born before the Big Bang, they affect the way galaxies are distributed in the sky in a unique way. This connection may be used to reveal their identity and make conclusions about the times before the Big Bang too," says Tommi Tenkanen, a postdoctoral fellow in Physics and Astronomy at the Johns Hopkins University and the study's author. While not much is known about its origins,...
Post a Comment
Read more

Scientists challenge notion of binary sexuality with naming of new plant species

A collaborative team of scientists from the US and Australia has named a new plant species from the remote Outback. Bucknell University biology postdoctoral fellow Angela McDonnell and professor Chris Martine led the description of the plant that had confounded field biologists for decades because of the unusual fluidity of its flower form. The discovery, published in the open access journal  PhytoKeys , offers a powerful example of the diversity of sexual forms found among plants. The new species of bush tomato discovered in remote Australia provides a compelling example of the fact that sexuality among Earth's living creatures is far more diverse -- and interesting -- than many people likely realize. Bucknell University postdoctoral fellow Angela McDonnell and biology professor Chris Martine led the study following an expedition last year to relocate populations of the new plant, which were first noted by Australian botanists during the 1970s. Herbarium specimens from th...
Post a Comment
Read more