RESUMO
White matter hyperintensities (WMHs) are frequently seen on brain magnetic resonance imaging scans of older people. Usually interpreted clinically as a surrogate for cerebral small vessel disease, WMHs are associated with increased likelihood of cognitive impairment and dementia (including Alzheimer's disease [AD]). WMHs are also seen in cognitively healthy people. In this collaboration of academic, clinical, and pharmaceutical industry perspectives, we identify outstanding questions about WMHs and their relation to cognition, dementia, and AD. What molecular and cellular changes underlie WMHs? What are the neuropathological correlates of WMHs? To what extent are demyelination and inflammation present? Is it helpful to subdivide into periventricular and subcortical WMHs? What do WMHs signify in people diagnosed with AD? What are the risk factors for developing WMHs? What preventive and therapeutic strategies target WMHs? Answering these questions will improve prevention and treatment of WMHs and dementia.
RESUMO
This review discusses current knowledge of the complex interactions between amyloid-beta (A beta) peptide, the receptor for advanced glycation endproducts (RAGE), and inflammatory mediators, focusing on the roles of such interactions in the pathogenesis of Alzheimer's disease. As a ubiquitous cell-surface receptor, RAGE demonstrates enhanced expression in an A beta-rich environment; the effects of RAGE on microglia, the blood-brain barrier and neurons are mediated through various signaling pathways. Relevant preclinical models illustrate that the A beta-RAGE interaction amplifies neuronal stress and the accumulation of A beta, impairs memory and learning, and exaggerates neuroinflammation. These findings suggest that RAGE may mediate a common proinflammatory pathway in neurodegenerative disorders.
