Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain glia cells increase their DNA content to preserve vital blood-brain barrier

16.01.2012
The blood-brain barrier is essential for maintaining the brain's stable environment—preventing entry of harmful viruses and bacteria and isolating the brain's specific hormonal and neurotransmitter activity from that in the rest of the body.

In addition to nerve cells, the brain contains glia cells that support and protect the neurons. In the fruit fly, the blood-brain boundary is made by glia joined into an envelope sealed around the nerve cells. As the brain rapidly expands during development, the glial envelope must grow correspondingly to remain intact. However, little has been known about how the blood-brain barrier maintains its integrity as the brain it protects develops.

Now Whitehead Institute scientists report that as the developing larval fruit fly brain grows by cell division, it instructs subperineurial glia (SPG) cells that form the blood-brain barrier to enlarge by creating multiple copies of their genomes in a process known as polyploidization. The researchers report their work this month in the journal Genes and Development.

"We think that this may be the same developmental strategy that's used in other contexts, where you need an outer layer of cells to maintain a seal, yet you also need the organ to grow during development," says Whitehead Member Terry Orr-Weaver.

Like the larval fruit fly's blood-brain barrier, cell layers in the human placenta and skin may employ polyploidization to respond to the need to expand while maintaining a sound boundary between the fetus and its surroundings, and the body and the outside world, respectively.

For preserving such barriers, polyploidy is ideal, as the cells forming the boundary enlarge without undergoing full cell division, a process that would break the tight junctions between cells.

In the larval fruit fly, polyploid SPG are necessary for maintaining the blood-brain barrier. When Yingdee Unhavaithaya, a postdoctoral researcher in Orr-Weaver's lab and first author of the Genes and Development article, prevented the SPG from making additional genome copies and becoming polyploid, the blood-brain barrier shattered as the brain continued to expand and the SPG was unable to accommodate its growth.

When allowed to progress naturally, polyploidy is flexible enough to accommodate even unusual brain expansion. After Unhavaithaya enlarged the brain by inducing a brain tumor, the SPG responded by increasing their ploidy and the blood-brain barrier remained unbroken.

This experiment also indicates that somehow the expanding brain mass is telling the SPG to increase their ploidy, but only as much as necessary to maintain the tight junctions between the SPG.

"It's a glimpse of communication between tissues during organogenesis," says Unhavaithaya. "We see different tissues trying to make a properly sized organ together. And one of the ways is by receiving instruction from the growing tissue so the other tissue can scale its size to properly conform to this tissue ratio for the organism."

For Orr-Weaver, Unhavaithaya's work could lead to additional exciting research.

"It has really opened up a whole new area to look at, so we can understand the mechanistic basis by which this communication happens," says Orr-Weaver, who is also an American Cancer Society professor of biology at MIT. "Does it happen at the organ level, or does it happen locally? There's really a lot to sort out."

This work was supported the Harold and Leila Mathers Charitable Foundation and the American Cancer Society.

Written by Nicole Giese Rura

Terry Orr-Weaver is a Member at Whitehead Institute for Biomedical Research, where her laboratory is located and all her research is conducted. She is also an American Cancer Society professor of biology at Massachusetts Institute of Technology.

Full Citation:

"Polyploidization of glia in neural development links tissue growth to blood-brain barrier integrity"

Genes and Development, January 1, 2012

Yingdee Unhavaithaya and Terry L. Orr-Weaver

Whitehead Institute and Dept. of Biology, Massachusetts Institute of Technology, Cambridge, MA.

Nicole Giese Rura | EurekAlert!
Further information:
http://www.wi.mit.edu

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>