Navigation Links
Dangerous custodians
Date:3/22/2010

Microglia are the cells responsible for immune surveillance in the brain, and they initiate protective inflammatory reactions in response to tissue damage and infection. An international team under the leadership of LMU neuroscientist Professor Jochen Herms has now shown that these cells may actually make a significant contribution to the loss of neurons associated with Alzheimer's disease. About 1.2 million people are thought to suffer from this form of progressive dementia in Germany, and this figure is expected to double as the average age of the population continues to increase. Their new findings lead Professor Herms and his team to believe that, as the disease develops, stressed nerve cells secrete a chemical messenger that attracts microglia. The ensuing inflammatory reactions ultimately result in the elimination of the neurons. This implies that chemical signalling between nerve cells and microglia plays an important role in mediating neuron loss during the course of the disease. "We may be able to make use of these results to develop novel agents that can slow the rate of neuron loss by interrupting communications between the two cell types", says Herms. (Nature Neuroscience online, 21 March 2010)

It is estimated that as many as 18 million people currently suffer from Alzheimer's disease worldwide, and the numbers are rising. This form of progressive dementia is due to an inexorable loss of nerve cells from the brain that is associated with the formation of insoluble protein aggregates, called beta-amyloid plaques and tangles. Large numbers of microglia gather in the vicinity of these plaques. Microglia serve as immune "policemen" that use their long processes to monitor their surroundings for signs of tissue damage. In accordance with this role, it has been thought that they congregate near plaques in order to degrade them.

Using two-photon microscopy, Professor Herms and his colleagues at the LMU's Center for Neuropathology were able to look directly into the brains of genetically modified mice that develop many of the symptoms characteristic of Alzheimer's disease in humans. The mice had also been engineered to make fluorescent forms of proteins that are specific for neurons and microglia, and the imaging technique enabled the researchers to monitor the fate of identifiable neurons and microglia over periods of weeks and months.

This approach made it possible, for the first time, to visualize the loss of nerve cells in the brains of living mice. Nerve loss was found to be preceded by the activation of microglia. "We assume that the sick nerve cells near plaques secrete a chemical messenger that induces the microglia to home in on them", says Herms. "The best candidate for the messenger responsible is the chemokine fractalikine, which docks onto a receptor protein on the surface of the microglial cells." Indeed, when this receptor was genetically eliminated, nerve cell loss was prevented.

These results demonstrate that microglia are not only involved in the removal of the amyloid aggregates typical of Alzheimer's disease, they also contribute actively to the catastrophic loss of nerve cells. In this picture, the communication channel between nerve cell and microglia that is mediated by the fractalkine receptor plays a crucial role in the pathology of Alzheimer's disease. "The new findings could possibly lead to new therapeutic approaches to preventing neuron loss", says Herms.


'/>"/>

Contact: Dr. Jochen Herms
Jochen.Herms@med.uni-muenchen.de
49-892-180-78010
Ludwig-Maximilians-Universitt Mnchen
Source:Eurekalert

Related biology news :

1. Stopping MRSA before it becomes dangerous is possible, Sandia/UNM researchers find
2. Avoiding dangerous climate change: Is geo-engineering the answer?
3. IAEA removes dangerous radioactive sources from Lebanon
4. UA pharmacy research shows prescribers miss potentially dangerous drug pairs
5. Study characterizes eczema patients most at risk for dangerous viral infections
6. They are young and need the job: A second chance for dangerous T-cells
7. CSHL researchers explain process by which cells hide potentially dangerous DNA segments
8. Dangerous printer particles identified
9. NYU scientists discover dangerous new method for bacterial toxin transfer
10. Mayo researchers identify dangerous two-faced protein crucial to breast cancer spread and growth
11. Warming world in range of dangerous consequences
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/7/2016)... TORONTO , June 7, 2016  Syngrafii ... begun a business relationship that includes integrating Syngrafii,s ... pilot branch project. This collaboration will result in ... for the credit union, while maintaining existing document ... http://photos.prnewswire.com/prnh/20160606/375871LOGO ...
(Date:6/2/2016)... , June 2, 2016 The Department ... has awarded the 44 million US Dollar project, for the ... Vehicle Plates including Personalization, Enrolment, and IT Infrastructure , ... in the production and implementation of Identity Management Solutions. Numerous ... however Decatur was selected for the ...
(Date:6/2/2016)... 2016 Perimeter Surveillance & Detection ... Physical Infrastructure, Support & Other Service  The ... offers comprehensive analysis of the global Border Security ... revenues of $17.98 billion in 2016. Now: ... leader in software and hardware technologies for advanced video ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... ... STACS DNA Inc., the sample tracking software company, today announced that Dr. Hays ... DNA as a Field Application Specialist. , “I am thrilled that Dr. Young ... DNA. “In further expanding our capacity as a scientific integrator, Hays brings a wealth ...
(Date:6/23/2016)...  Blueprint Bio, a company dedicated to identifying, protecting ... has closed its Series A funding round, according to ... "We have received a commitment from Forentis Fund that ... meet our current goals," stated Matthew Nunez . ... complete validation on the current projects in our pipeline, ...
(Date:6/23/2016)... ... June 23, 2016 , ... ClinCapture, the only free validated ... will showcase its product’s latest features from June 26 to June 30, 2016 ... on Disrupting Clinical Trials in The Cloud during the conference. DIA (Drug ...
(Date:6/23/2016)... -- Amgen (NASDAQ: AMGN ) today announced a ... sciences incubator to accelerate the development of new therapies ... QB3@953 was created to help high-potential life science and ... stage organizations - access to laboratory infrastructure. ... "Amgen Golden Ticket" awards, providing each winner with one ...
Breaking Biology Technology: