Alzheimer’s disease pathogenesis and therapeutic interventions

• Published in: Journal of Clinical Neuroscience 2004-06, Vol.11 (5), p.456-467
• Main Authors: Parihar, M.S, Hemnani, Taruna
• Format: Article
• Language: English
• Subjects: Alzheimer Disease - genetics; Alzheimer Disease - physiopathology; Alzheimer Disease - therapy; Alzheimer’s disease; Animals; free radicals; Humans; mitochondria; Models, Biological; neurodegenerative disorder; neuroprotection; β-amyloid
• ISSN: 0967-5868; 1532-2653
• DOI: 10.1016/j.jocn.2003.12.007

Alzheimer’s disease (AD) is a neurodegenerative disorder of the central nervous system associated with progressive cognitive and memory loss. Molecular hallmarks of the disease are characterized by extracellular deposition of the amyloid β peptide (Aβ) in senile plaques, the appearance of intracellular neurofibrillary tangles (NFT), cholinergic deficit, extensive neuronal loss and synaptic changes in the cerebral cortex and hippocampus and other areas of brain essential for cognitive and memory functions. Aβ deposition causes neuronal death via a number of possible mechanisms including oxidative stress, excitotoxicity, energy depletion, inflammation and apoptosis. Despite their multifactorial etiopathogenesis, genetics plays a primary role in progression of disease. To date genetic studies have revealed four genes that may be linked to autosomal dominant or familial early onset AD (FAD). These four genes include: amyloid precursor protein (APP), presenilin 1 (PS1), presenilin 2 (PS2) and apolipoprotein E (ApoE). Plaques are formed mostly from the deposition of Aβ, a peptide derived from APP. The main factors responsible for Aβ formation are mutation of APP or PS1 and PS2 genes or ApoE gene. All mutations associated with APP and PS proteins can lead to an increase in the production of Aβ peptides, specifically the more amyloidogenic form, Aβ42. In addition to genetic influences on amyloid plaque and intracellular tangle formation, environmental factors (e.g., cytokines, neurotoxins, etc.) may also play important role in the development and progression of AD. A direct understanding of the molecular mechanism of protein aggregation and its effects on neuronal cell death could open new therapeutic approaches. Some of the therapeutic approaches that have progressed to the clinical arena are the use of acetylcholinesterase inhibitors, nerve growth factors, nonsteroidal inflammatory drugs, estrogen and the compounds such as antioxidants, neuronal calcium channel blockers or antiapoptotic agents. Inhibition of secretase activity and blocking the formation of β-amyloid oligomers and fibrils which may inhibit fibrilization and fibrilization-dependent neurotoxicity are the most promising therapeutic strategy against the accumulation of β-amyloid fibrils associated with AD. Furthermore, development of immunotherapy could be an evolving promising therapeutic approach for the treatment of AD.