MIT examined transcription across tens of thousands of individual cells in both Alzheimer’s and healthy brains and found APOE strongly upregulated in the microglia and perturbation in myelination-related processes in multiple cell types including oligodendrocytes.
Could autophagy dysregulation link neurotropic viruses to Alzheimer’s disease?
The cellular housekeeping function of autophagy may play a role in Alzheimer’s as dysfunction could result in the accumulation of amyloid. HHV-6A, HHV-6B and HSV1 can infect central nervous system cells and dysregulate autophagy.
Herpesviruses may reduce NK cell cytotoxicity in Alzheimer’s
MS patients with a particular haplotype on natural killer cells are more susceptible to HHV-6A infection. Similarly, HHV-6A/B may contribute to Alzheimer’s by utilizing a specific NK cell inhibitory receptor to disrupt the ability of NK cells to clear infected cells.
HHV-6 small non-coding RNA proposed as an indicator of an early stage of HHV-6 reactivation
German investigators have identified a marker for what they believe is the earliest stage of viral reactivation, or “transactivation” marked by transcription of several viral small non-coding RNAs in the absence of detectable viral replication. The group believes that these viral small RNAs could be developed as biomarkers.
National Institute on Aging encourages grant proposals on HHV-6A & HHV-7 in Alzheimer’s
NIH leaders of the National Institute on Aging (NIA) encouraged investigators with experience in virology and infectious disease to apply for funding to study Alzheimer’s disease. The encouragement came at a workshop held at the Alzheimer’s Association International Conference in Chicago on July 22nd.
Gene-expression network analysis points to HHV-6A as a key driver in upregulating genes leading to Alzheimer’s disease progression
Investigators at Mt Sinai used “big data” models to determine that the genes involved with fighting Alzheimer’s are the same ones that fight virus. They found HHV-6A and HHV-7 to be more abundant in Alzheimer’s brains, and singled out HHV6-A as a key modulator of the genes involved in amyloidosis and neuronal death.
HHV-6 and HSV1 dramatically accelerate amyloid plaque production in Alzheimer’s model
Researchers at Harvard studied how neurons responded to the presence of herpesviruses HSV1 and HHV-6, and found that they rapidly induce amyloid plaque production within 24 to 48 hours.
Antiviral therapy reduces risk of dementia in Taiwan seniors with a history of acute herpesvirus infections
Large insurance data studies in Taiwan have found that seniors with shingles or serious HSV1 infections have a 2-3 fold increased risk of certain forms of dementia, and that antiviral treatment can reduce that risk by 90%.
Decreased HHV-6 IgG in Alzheimer’s
Investigators from Uppsala University in Sweden found that HHV-6 IgG reactivity was significantly lower in Alzheimer’s Disease patients compared to controls. The authors suggest reduced immunity may be one reason why past studies have found increased levels of HHV-6 DNA in the brains of Alzheimer’s patients compared to controls.
CXCL11 and CCL2 are specific to HHV-6B in febrile infants
Japanese investigators from Kobe University identified CXC11 as a chemokine uniquely expressed in primary HHV-6B infections. They also confirmed a previous finding that cytokine CCL2 (MCP-1) plays a role in HHV-6B primary infections. Both CXCL11 and CCL2 are expressed in several neuroinflammatory conditions including epilepsy, Alzheimer’s disease and traumatic brain injury.
Elevated levels of HHV-6 DNA in Alzheimer’s, linked to variants in antiviral genes
A group from Italy’s University of Bologna report that genetic defects in antimicrobial defense mechanisms can leave some individuals vulnerable to sub-clinical infections that lead to cognitive decline as they age. They found variations in specific antiviral genes that correlate with HHV-6 DNA levels in brain tissue and blood from patients with Alzheimer’s disease.
HHV-6 and EBV identified as risk factors in Alzheimer’s Disease
New data suggests HHV-6 and EBV are associated with the development of Alzheimer’s in elderly persons.
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