Skip to main content

Astrocytes protect neurons from toxic buildup

Astrocytes are overtaxed neurons' pit crew.
The brain cells collect damaged lipids secreted by hyperactive neurons, then recycle those toxic molecules into energy, researchers at the Howard Hughes Medical Institute's Janelia Research Campus report May 23, 2019, in the journal Cell. It's a mechanism to protect neurons from the damaging side effects of overactivity. And it's another important role for astrocytes, which support neurons in various ways.
When a neuron fires fast and furious, lipid molecules in the cell get damaged and can become toxic. While most kinds of cells sequester excess fatty acids away or feed them to mitochondria to prevent buildup, neurons don't seem to rely on those tricks.
Instead, "neurons unload some of the burden to astrocytes," says study coauthor and Janelia Group Leader Zhe Liu, who worked closely with Maria Ioannou and Jennifer Lippincott-Schwartz, a senior group leader at Janelia. "For a long time, people have suspected there was some mechanism like this. The new work shows how this process actually happens."
The finding arose from a curious observation: Overactive neurons release damaged fatty acids bundled up in lipid particles. "People didn't think that neurons could secrete those lipid particles," Liu says.
But stimulating mouse neurons in a dish led to the buildup of fatty acids and, eventually, lipid particle release, the team showed. Then, nearby astrocytes engulfed the particles and amped up the activity of genes involved in energy production and detoxification.
Astrocytes feed neurons' off-loaded damaged lipids to their own mitochondria, converting waste into energy, Liu concluded. Tests in mice showed a similar response. After a lesion to the brain that mimics a stroke -- a huge stress to neurons -- neurons increased production of proteins involved in transporting fatty acids out of the cell, and fatty acids built up in astrocytes.
This pathway for clearing toxic molecules from neurons might be damaged in Alzheimer's patients, Liu proposes, though that hasn't been thoroughly investigated. A next step, led by Maria Ioannou in her new lab at the University of Alberta, is to examine what's different about this mechanism in cell culture and rodent models of Alzheimer's disease.
Story Source:
Materials provided by Howard Hughes Medical Institute. 
Note: Content may be edited.

Comments

Post a Comment

Popular posts from this blog

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

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

GSAT-11 satellite to be launched from French Guiana on Dec 5th

GSAT-11 satellite to be launched from French Guiana on Dec 5th GSAT-11 would be located at 74 East and is the fore-runner in a series of advanced communications satellite with multi-spot beam antenna coverage over Indian mainland and Islands, ISRO said. GSAT-11 is the next generation “high throughput” communication satellite configured around ISRO’s I-6K Bus. (PTI/Representational). Indian space agency ISRO is scheduled to launch GSAT-11, the “heaviest” satellite built by it, on-board Ariane-5 rocket of Arianespace from French Guiana on December 5. Weighing about 5,854 kg, GSAT-11 would play a vital role in providing broadband services across the country, and also provide a platform to demonstrate new generation applications, the Indian Space Research Organisation (ISRO) said. It is the “heaviest” satellite built by ISRO, the space agency said. GSAT-11 is the next generation “high throughput” communication satellite configured around ISRO’s  I-6K Bus, and it...
Post a Comment
Read more