Amnesia Research Today is a free monthly online journal that collates and summarizes the latest research about Amnesia, including details on memory loss, causes, treatment, brain injury,.

A humanin derivative, S14G-HN, prevents amyloid-beta-induced memory impairment in mice.

Tajima H, Kawasumi M, Chiba T, Yamada M, Yamashita K, Nawa M, Kita Y, Kouyama K, Aiso S, Matsuoka M, Niikura T, Nishimoto I

Department of Pharmacology and Neurosciences, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.

Humanin (HN) is a 24-amino acid peptide that protects neuronal cells from death caused by Alzheimer's disease (AD)-related genes and amyloid-beta (Abeta). Multiple studies have revealed its biochemical and neuroprotective characteristics in vitro; however, little has been known regarding whether HN is effective in vivo in AD model systems. We examined the effect of S14G-HN, a 1,000-fold more potent derivative of HN in vitro, on amnesia induced by Abeta25-35 in mice. The Y-maze test revealed that at least 50 pmol of S14G-HN by intracerebroventricular injection prevented Abeta-induced impairment of short-term/spatial working memory; however, 5 nmol of S14A-HN, a neuroprotection-defective mutant in vitro, did not prevent Abeta-induced amnesia. These results are in agreement with the structure-function correlation shown previously in vitro. In the water-finding task, S14G-HN prevented prolongation of finding latency (the time to find water) observed in Abeta-amnesic mice, indicating that S14G-HN also blocked Abeta-induced impairment of latent learning. In accordance with these observations, immunohistochemical analysis showed that S14G-HN sustained the number of cholinergic neurons in the basal forebrain and the striata nearly to the normal level. Furthermore, genistein, a specific inhibitor of tyrosine kinases, blocked recovery from scopolamine-induced amnesia by S14G-HN, suggesting that certain tyrosine kinase(s) are involved in the inhibitory function of S14G-HN in vivo. Taking these findings together, we conclude that S14G-HN has rescue activity against memory impairment caused by AD-related insults in vivo by activating the same intracellular neuroprotective machinery as elucidated previously in vitro.

Published 22 February 2005 in J Neurosci Res, 79(5): 714-23.
Full-text of this article is available online (may require subscription).

© 2004-2008 Amnesia Research Today. All Rights Reserved.