HEALTH NEWS

Study Title:

NAC Protects Memory

Study Abstract

As one of the dominant amyloid-beta peptide (Abeta) proteases, neprilysin (NEP) plays a crucial role in maintaining a physiologic balance between Abeta production and catabolism. We have previously shown that NEP is modified by 4-hydroxynonenal (HNE) adducts, resulting in decreased activity in the brain of AD patients and cultured cells. In order to determine whether antioxidants can rescue NEP, SH-SY5Y cells were treated with HNE or Abeta, together with N-acetylcysteine for 24 hours, prior to analysis of NEP protein levels, activity, and oxidative modifications. Intracellular NEP developed HNE adducts after 24 hours of HNE or Abeta treatment as determined by immunoprecipitation, immunoblotting, and double immunofluorescence staining. N-acetylcysteine at 10 to 100 muM alleviated HNE adduction after HNE or Abeta treatment. In keeping with previous reports, HNE-modified NEP showed decreased catalytic activity. The present study demonstrates that antioxidants can be used to spare NEP from oxidative modification, suggesting a potential mechanism underlying the neuroprotective effects of antioxidants in aging or Alzheimer's disease.

Study Information

Wang R, Malter JS, Wang DS.
N-Acetylcysteine Prevents 4-Hydroxynonenal- and Amyloid-beta-Induced Modification and Inactivation of Neprilysin in SH-SY5Y Cells.
J Alzheimers Dis.
2009 September
Department of Pathology and Laboratory Medicine, and Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.