One Step Closer: New Alzheimer’s Gene Discovered
Alzheimer’s Disease (AD) is the most prevalent form of dementia, and sixth leading cause of death in the US, affecting 60-80% of individuals 65 and older. The hallmark symptom of Alzheimer’s Disease is serious memory loss attributed to widespread cell death and loss of cortical mass. Treatments are currently used to stop and slow the progression of the disease, and improve patients’ quality of life as there is no cure for AD.
The molecular basis of neurodegeneration in Alzheimer’s Disease is in amyloid beta plaque formation and the accumulation of neurofilaments. Studies have shown that aggregates of -amyloid form amyloid plaques that are predominantly found in the brains of Alzheimer’s patients. The accumulation of amyloid plaques in the brain impairs neuronal function and leads the eventual death of cells.
Recently, researchers have pinpointed a gene involved with the immune system, IL1RAP, that increases the risk of developing AD. In a genome-wide analysis of over 500 individuals, those with the IL1RAP variant were found to have a greater accumulation of amyloid plaque over a two year period – independent of the previously highly speculated AD-linked allele APOE ε4.
IL1RAP, or Interleukin-1 receptor accessory protein, is associated with the immune system, and often regulates microglial activity (“the brain’s ‘garbage disposal system’.”) Studies have shown that microglial cells gather around plaques and clear amyloid deposits. The presence of IL1RAP displays altered microglial activity, featuring faster accumulation of amyloid plaque, increased cognitive decline, and increased cortical decline. Focusing on the IL1RAP pathway may be imperative in inducing plaque destruction, therefore halting the progression of Alzheimer’s Disease. Researching this pathway may be key in eventually creating a cure.
-Kavya Raghunathan
Sources
(Original Study) GWAS of longitudinal amyloid accumulation on 18F-florbetapir PET in Alzheimer’s disease implicates microglial activation gene IL1RAP- http://brain.oxfordjournals.org/content/138/10/3076
New Gene Linked to Amyloid Plaque Buildup in Alzheimer’s Disease Identified- http://neurosciencenews.com/il1rap-alzheimers-apoee4-genetics-2826/
New Alzheimer’s Gene Identified- http://www.medscape.com/viewarticle/852556
What Is Alzheimer’s?- http://www.alz.org/alzheimers_disease_what_is_alzheimers.asp
Image by user Freesci via Wikimedia Commons
