THE SYNAPTIC PROTEIN NACP IS ABNORMALLY EXPRESSED DURING THE PROGRESSION OF ALZHEIMERS-DISEASE

NACP, the precursor of non-A beta component of Alzheimer's disease (AD ) amyloid (NAC), is a synaptic protein that could potentially be invol ved in AD. We studied, by dot-blot, NACP levels in the frontal cortex of AD cases staged according to severity of disease and correlated the m with cognitive performance and neuropathological markers. Early AD c ases showed one fold higher levels of NACP immunoreactivity (IR) compa red to moderate and severe AD. Levels of NACP-IR were correlated with tangle counts (r = -0.305, P = 0.04) and Blessed score (r = -0.356, P = 0.01), but not with plaque counts (r = 0.132, P = 0.39). This study suggests that the abnormal accumulation of NACP during the early stage s of AD might play an important role in the mechanisms of neurodegener ation and synaptic damage in AD.