Alzheimer's disease

• Alzheimer's disease is the most common type of dementia.
• It affects tens of millions of people worldwide, and this number is rising dramatically.
• The social and economic burden of Alzheimer's disease is high.
• Forgetfulness and memory problems are often early symptoms, but as the illness progresses, patients tend to become confused, may lose their way around familiar places, and have difficulties with planning and completing simple tasks.

Cause

• The amyloid hypothesis proposes β-amyloid (Aβ) as the main cause of the disease.
• The mis-folding of the extracellular Aβ protein accumulated in senile plaques and the intracellular deposition of misfolded protein in neurofibrillary tangles cause memory loss and confusion and result in personality and cognitive decline over time.
• Accumulated Aβ peptide is the main component of senile plaques and derives from the proteolytic cleavage of a larger glycoprotein named amyloid precursor protein (APP).
• APP is a type 1 membrane glycoprotein that plays an important role in a range of biological activities, including neuronal development, signaling, intracellular transport, and other aspects of neuronal homeostasis.
• Several APP cleavage products may be major contributors to Alzheimer's disease, causing neuronal dysfunction.