Alzheimer’s disease has affected over 4.5 million people within the United States, and the number is expected to grow to 13 million by the year 2050. Economically, this presents a huge problem. In 2009, $144 billion (per year) was spent on healthcare for patients with dementia. That turns out to be an average yearly cost of $33,000 per person. Obviously, this is less than manageable for many Alzheimer’s disease patients, which is why research into the disease is crucial for the advancement of treatment.
Alzheimer’s disease is a chronic, neurodegenerative disease of the brain that has been characterized by neuronal loss, b-amyloid plaque deposits, increased activity of catabolic genes and pathways, decreased energy production, mitochondrial activity, and free radical stress. Most importantly, it affects areas of the brain associated with learning and memory. However, it can also affect other areas of the brain. Two of the most common symptoms of Alzheimer’s disease are memory loss and dementia. By examining the MAPK signaling pathways, one can identify the mechanisms in which memory loss and dementia occur.
As stated before, b-amyloid plaque deposits are a major element in Alzheimer’s disease. Along with neurofibrillary tangles, b-amyloid plaques result in cognitive and memory dysfunction. Tau, a microtubule-associated protein, is known to be present in the neurofibrillary tangles. Since its phosphorylation is mediated by several kinases (JNK, p38, and ERK), it affects the MAPK pathways. Also, oxidative stress plays a key role in Alzheimer’s disease and is involved with the JNK and p38 pathways. An activated MAPK pathway is hypothesized to aid in the development of Alzheimer’s disease. The mechanisms in which it operates include induction of neuronal apoptosis, transcriptional and enzymatic activation of b- and g-secretases, and APP phosphorylation.
In recent years of research, scientists have made dramatic progress in understanding Alzheimer’s disease. Four genes have been linked to the disease. The mechanisms by which altered amyloid and tau protein metabolism, inflammation, oxidative stress, and hormonal changes may produce neuronal degeneration are being identified. This has led to the hypothesis that Alzheimer’s disease develops via MAPK signaling pathways.
Alzheimer's Disease Has A Pathway
