Navigation Links
Brain glia cells increase their DNA content to preserve vital blood-brain barrier
Date:1/13/2012

CAMBRIDGE, Mass. (January 13, 2012) The blood-brain barrier is essential for maintaining the brain's stable environmentpreventing 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."


'/>"/>

Contact: Nicole Giese Rura
rura@wi.mit.edu
617-258-6851
Whitehead Institute for Biomedical Research
Source:Eurekalert

Related biology news :

1. Penn biophysicists create new model for protein-cholesterol interactions in brain and muscle tissue
2. During exercise, the human brain shifts into high gear on alternative energy
3. Millisecond brain signals predict response to fast-acting antidepressant
4. Food for thought -- regulating energy supply to the brain during fasting
5. Risk and reward compete in brain
6. Brainy genes, not brawn, key to success on mussel beach
7. Brain-nourishing molecule may predict schizophrenia relapse
8. Brain structure provides key to unraveling function of bizarre dinosaur crests
9. MU brain imaging center provides research for autism, schizophrenia and Parkinsons disease
10. Key to function of dinosaur crests found in brain structure
11. Emotion and scent create lasting memories -- even in a sleeping brain
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/21/2016)... 21, 2016 NuData Security announced today that ... of principal product architect and that Jon ... customer development. Both will report directly to ... moves reflect NuData,s strategic growth in its product ... customer demand and customer focus values. ...
(Date:6/9/2016)... June 9, 2016 Paris ... Teleste,s video security solution to ensure the safety of people ... during the major tournament Teleste, an international ... and services, announced today that its video security solution will ... to back up public safety across the country. The system ...
(Date:6/2/2016)... Perimeter Surveillance & Detection Systems, ... Infrastructure, Support & Other Service  The latest ... comprehensive analysis of the global Border Security market ... of $17.98 billion in 2016. Now: In ... in software and hardware technologies for advanced video surveillance. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , ... June 23, 2016 , ... ... release of its second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering ... retention in this eBook by providing practical tips, tools, and strategies for clinical ...
(Date:6/23/2016)... , June 23, 2016 A person commits ... the crime scene to track the criminal down. ... U.S. Food and Drug Administration (FDA) uses DNA evidence to ... Sound far-fetched? It,s not. The FDA has ... to support investigations of foodborne illnesses. Put as simply as ...
(Date:6/23/2016)... , June, 23, 2016  The Biodesign Challenge ... envision new ways to harness living systems and biotechnology, ... Art (MoMA) in New York City ... 130 participating students, showcased projects at MoMA,s Celeste Bartos ... Paola Antonelli , MoMA,s senior curator of architecture and ...
(Date:6/23/2016)... Durham, NC (PRWEB) , ... June 23, 2016 , ... ... Odense University Hospital in Denmark detail how a patient who developed lymphedema after being ... (fat) tissue. The results could change the paradigm for dealing with this debilitating, frequent ...
Breaking Biology Technology: