Researchers identify toehold for HIV's assaul...(n and gait disturbances. In later stages...),Health
n, and gait disturbances. In later stages, neuroAIDS can cause outright dementia.
Gelbard's team discovered that Tat works through the ryanodine receptor to sicken neurons in two ways. Scientists have known that Tat makes vulnerable the mitochondria, organelles within neurons and other cells that are commonly considered the "power packs" or energy sources for cells. The team discovered that Tat destroys the ability of mitochondria to protect themselves from changes in levels of calcium.
The scientists discovered another effect of Tat as well. Tat has a dramatic effect on an organelle known as the endoplasmic reticulum, where proteins are actually assembled and folded. Gelbard's team discovered that it's Tat's effects on the ryanodine receptor that cause an "unfolded protein response" seen in the brains of HIV patients. Shape is everything for proteins, and they're nearly always useless or harmful when they are unfolded or misfolded. The problem in HIV patients is exacerbated because protein folding requires a great deal of energy energy that cells whose mitochondria are petering out aren't likely to have.
The team also showed, in mice, that a single exposure to Tat has long-lasting effects on the brain, causing problems with mitochondria and endoplasmic reticulum weeks later. Perhaps most striking, Gelbard says, is the observation that the exact same types of damage were seen in brain tissue of patients with HIV and neurologic disease but not in tissue from patients with HIV who did not have the neurologic disease.
The findings are in line with past findings from the team, which has shown that the central problem in HIV dementia is not that brain cells simply die. Rather, they become sick and lose their ability to communicate with each other. Because the cells are still alive, there is hope that the condition could be stopped or even reversed with proper treatment. Indeed, doctors commonly see patients who begin antiviral thera
'/>"/>
| Contact: Tom Rickey tom_rickey@urmc.rochester.edu 585-275-7954 University of Rochester Medical Center Source:Eurekalert |
Related medicine news :
1. Researchers Tackle CLL, Diabetes and Trauma-Hemorrhage
2. Researchers Use New Method to Control Bleeding in Hemophilia
3. Stem cells with potential to regenerate injured liver tissue identified by Penn researchers
4. Protein can nurture or devastate brain cells, depending on its friends, researchers find
5. Researchers find stem cells from monkey teeth can stimulate growth and generation of brain cells
6. Battling Bacteria in the Blood: U-M Researchers Tackle Deadly Infections
7. Researchers to Present Additional Data on Soliris(R) (eculizumab) for the Treatment of PNH at the ASH Annual Meeting
8. USC researchers identify key mechanism that regulates the development of stem cells into neurons
9. Cornell researchers study showing evidence of a major environmental trigger for autism
10. Maastricht University researchers produce neural fingerprint of speech recognition
11. Researchers aim to over-stress already taxed mantle cell lymphoma cells
| Copyright © 2003-2009 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |