Current Opinion in Psychiatry
Geriatric psychiatry: Edited by Edmond Chiu and Orestes Forlenza
Neurofibrillary degeneration in Alzheimer's disease: from molecular mechanisms to identification of drug targets
Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, KI-ADRC, Novum, Stockholm, Sweden
Correspondence to Jin-Jing Pei, MD, PhD, Associate Professor, Karolinska Institutet, KI-Alzheimer Disease Research Center (KI-ADRC), Novum Plan 5, Novum S-141 57, Huddinge, Sweden Tel: +46 8 585 83649; fax: +46 8 585 83880; e-mail: [email protected]
Abstract
Purpose of review
Great progress has been made in understanding the pathogenesis of neurofibrillary degeneration in Alzheimer's disease brains in the last two decades. In this review we summarize how neurons are degenerated in Alzheimer's disease brains and highlight the evidence of using kinases such as glycogen synthase kinase 3 and p70 S6 kinase and phosphatases such as protein phosphatase 2A as drug targets to prohibit the formation of neurofibrillary degeneration of Alzheimer's disease.
Recent findings
In general there are two types of neuronal degeneration in Alzheimer's disease brains: neurofibrillary formation and apoptosis. The microtubule-associated protein tau that stabilizes neuronal microtubules under normal physiological conditions is abnormally hyperphosphorylated in Alzheimer's disease brains, resulting in the generation of aberrant aggregates that are toxic to neurons. The processes of tau hyperphosphorylation and the formation of neurofibrillary tangles are caused by the imbalance of the activities of protein kinases and protein phosphatases in Alzheimer's disease brains. Recent findings from our and other groups have suggested glycogen synthase kinase 3 and p70 S6 kinase as main tau kinases and protein phosphatase 2A as the main tau phosphatase involved in the formation of these processes. Activities of these targets are implicated by Aβ peptide, the major component of another hallmark in Alzheimer's disease brains, senile plaques.
Summary
To prevent the clinical progression of neurodegeneration, a combination strategy is suggested to target both senile plaques with immunization and neurofibrillary tangles with drugs to prevent the synthesis and phosphorylation of tau.