Featured Research

from universities, journals, and other organizations

An early step in Parkinson's disease: Problems with mitochondria

Date:
February 15, 2011
Source:
Emory University
Summary:
For the last several years, neurologists have been probing a connection between Parkinson's disease and problems with mitochondria, the miniature power plants of the cell. Now researchers have found that a protein called MEF2D, which helps brain cells withstand stress and toxins, also plays an unexpected role inside mitochondria. MEF2D's ability to keep mitochondria well tuned appears to be especially sensitive to impairment in Parkinson's disease.

For the last several years, neurologists have been probing a connection between Parkinson's disease and problems with mitochondria, the miniature power plants of the cell.

Toxins that mimic Parkinson's effects act specifically to poison mitochondria, and mitochondria appear to be damaged in the brain cells that are endangered in the disease. But one unresolved question has been: are mitochondria simply the vulnerable "canaries in the coal mine" or is their deterioration a key step on the way to neurodegeneration?

Now researchers at Emory University School of Medicine have found that a protein called MEF2D, which helps brain cells withstand stress and toxins, also plays an unexpected role inside mitochondria. MEF2D's ability to keep mitochondria well tuned appears to be especially sensitive to impairment in Parkinson's disease, the research team found.

The results will be published online in the Journal of Clinical Investigation.

"Our data suggest that problems with MEF2D in mitochondria could represent one of the earlier steps in the progress of the disease," says senior author Zixu Mao, PhD, associate professor of pharmacology and neurology at Emory University School of Medicine. Postdoctoral researcher Hua She, PhD, was the first author.

The Emory team showed that MEF2D binds one particular mitochondrial gene, ND6, which is necessary for assembly of complex I. Complex I begins the electron transport process that is necessary for mitochondria to function.

Mitochondria are thought to have evolved from bacteria that once lived independently, but were engulfed and harnessed by a primitive cell millions of years ago. Mao and his colleagues found an example of how this symbiosis has extended to having proteins like MEF2D turn on genes inside mitochondria.

"Our findings make a convincing and very intriguing case that dysregulation of mitochondrial DNA gene expression contributes to Parkinson's," Mao says.

Genes in the nucleus (that is, outside mitochondria) now encode most of the proteins that go into mitochondria. However, mitochondria still make a few of their own proteins, such as ND6.

In addition to showing how MEF2D functions in mitochondria, the team showed that toxins such as MPTP and the natural pesticide rotenone, which interfere with complex I and bring on Parkinson's in animals, also block MEF2D from working in mitochondria.

Mao's laboratory's previous research found that in Parkinson's, MEF2D levels are increased in the cell because of defects in a recycling process called autophagy. Now, they show that in the brains of Parkinson's patients, even when MEF2D levels are increased in the cell as a whole, they are reduced in mitochondria.

Because disruptions in mitochondria have been linked to other neurodegenerative diseases and heart disease as well, Mao says probing MEF2D's involvement in those disease processes may yield new insights.

The research was funded by the National Institutes of Health, the Woodruff Health Sciences Center Fund, and the Michael J. Fox Foundation.


Story Source:

The above story is based on materials provided by Emory University. The original article was written by Quinn Eastman. Note: Materials may be edited for content and length.


Journal Reference:

  1. H. She, Q. Yang, K. Shepherd, Y. Smith, G. Miller, C. Testa and Z. Mao. Direct regulation of complex I by mitochondrial MEF2D is disrupted in a mouse model of Parkinson disease and in human patients. J. Clin. Invest.,

Cite This Page:

Emory University. "An early step in Parkinson's disease: Problems with mitochondria." ScienceDaily. ScienceDaily, 15 February 2011. <www.sciencedaily.com/releases/2011/02/110214122707.htm>.
Emory University. (2011, February 15). An early step in Parkinson's disease: Problems with mitochondria. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2011/02/110214122707.htm
Emory University. "An early step in Parkinson's disease: Problems with mitochondria." ScienceDaily. www.sciencedaily.com/releases/2011/02/110214122707.htm (accessed September 19, 2014).

Share This



More Health & Medicine News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
How The 'Angelina Jolie Effect' Increased Cancer Screenings

How The 'Angelina Jolie Effect' Increased Cancer Screenings

Newsy (Sep. 19, 2014) Angelina's Jolie's decision to undergo a preventative mastectomy in 2013 inspired many women to seek early screenings for the disease. Video provided by Newsy
Powered by NewsLook.com
The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins