Continuing the Debate Over Viral Contributions to Alzheimer ' s Disease

Persistent viral infection may be an important contributing cause of Alzheimer's disease, either because the amyloid-β associated with Alzheimer's disease is a part of the innate immune response, and infection thereby increases production, or because persistent infection drives the chronic inflammation that disrupts the biochemistry of brain tissue. If viral infection does drive Alzheimer's disease, it may go some way towards explaining why the disease doesn't correlate with lifestyle factors such as weight, activity, and so forth, anywhere near as well as is the case for other common age-related conditions. It all sounds plausible, and the various mechanisms that may be involved certainly exist, but the supporting evidence from patient data is so far mixed, despite a few quite compelling studies. The hypothesis is by no means concretely demonstrated, but researchers here suggest that pathology may require multiple viruses, a possible explanation for confounding data in studies that only focus on one type of viral infection. Using a three-dimensional human tissue culture model mimicking the brain, researchers have shown that varicella zoster virus (VZV), which commonly causes chickenpox and shingles, may activate herpes simplex (HSV), another common virus, to set in motion the early stages of Alzheimer's disease. Normally HSV-1 - one of the main variants of the virus - lies dormant within the neurons of the brain, but when it is activated it leads to accumulation of...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs