Alzheimer's disease: another target for heparin therapy.

Alzheimer's disease (AD) is the leading cause of dementia and cognitive decline in the elderly. Brain tissue changes indicate that the two main proteins involved in AD are amyloid-beta (A-beta), which is associated with the formation of senile amyloid plaques, and tau, which is associated with the formation of neurofibrillary tangles. Although a central role for A-beta in the pathogenesis of AD is indisputable, considerable evidence indicates that A-beta production is not the sole culprit in AD pathology. AD is also accompanied by an inflammatory response that contributes to irreversible changes in neuronal viability and brain function, and accumulating evidence supports the pivotal role of complement and contact systems in its pathogenesis and progression. The complexity of AD pathology provides numerous potential targets for therapeutic interventions. Compounds that interact directly with A-beta protein or interfere with its production and/or aggregation can reduce the inflammatory and neurotoxic effects of A-beta, and heparin, a glycosaminoglycan mixture currently used in the prophylaxis and treatment of thrombosis, might be a candidate, as recent research has been extended to consider its nonanticoagulant properties, including its modulation of various proteases and anti-inflammatory activity.