Poster Presentation:
Alzheimer’s
Disease and Related Dementias IV
S21Y
and therefore 4-repeat Tau protein, and are associated FTDP-17. Using in vitro splicing assays and RNA 2” structure mapping we show that the alternative splicing of El0 is in part due to a stem-loop structun that can sequester the 5’.splice site and that the FTDP-I7 mutations close to the 5’-splice site act through disruption of this stem-loop structure and through direct strengthening of the the splice site. In a number of species we show that the ratio of EIO+:EIO- product increases as the intronic sequence of the stem-loop region changes from the human. In adult mouse brain only EIO+ Tau is expressed. Using an in vitro Fplicing assay we show that as the mouse sequence is gradually altered to the human sequence the EIO+:ElO- ratio change9 back to the ratio of the human gene. Using single-base and deletion mutations of the sequence of El0 and the intronic sequence upstream of the 3’. and downstream of the 5’.splice site we have identified a number of exonic and intronic splice enhancer and suppressor sequences, separate from the stem-loop element. Two major haplotypes of the tau gene differ by the presence (HI) or absence (H2) of a 237 bp xquence 711 bp upstream of EIO. Tau aggregates in PSP brain are predominantly EIO+, and association studies imply that the H2 haplotype is protective for PSP. When 2.kb clones of both the HI and H2 haplotypes including exon IO and the inclusion/deletion region were used in the in vitro splicing assay neither produced ElO+ product. However, an exonic mutation restored ElO+:ElO- ratio to wild type levels for HI. but Inot for H2 haplotype. Thi\ may explain the protective effect of the H2 haplotype in PSP.
SLEEP (9951 THEIR
AND ACTIVITY IN PATIENTS CO-RESIDING CARERS
Kay W Jonr.s. Deborah
J’&wvji,
Bath
Christopher
United
United
Kingdom;
Raearch A Alford,
.for the Care of the of the West ofEngland,
Institutr Univ
WITH DEMENTIA
AND
Elderly, Bristol
Kingdom
Sleep disorder 1.s common in dementia with a reported mean prevalence of 3X9. Diuturbancc at night can include poor or interrupted sleep, wandering & nocturnal confusion. It can be pan of a more general disruption in normal diurnal rhythms. These problems are distressing to the patient and any co-residing family and may lead to institutionalization of the patient. Wrist-worn actigraphy monitors allow continuous measurement of the motor component of behaviour and have been well validated. Thl, allows simultaneous monitoring of patients and caregivers at home, providing a quantitative comparison of sleep and activity patterns. 42 patients (30 with Alzheimer’s disease, 6 with vascular dementia & 6 with mzxed dementia; age range 56-93) bi their primary co-residing carers (age range 41-86) were monitored continuously for average periods of 5 days. Similar data were collected on 29 control subjects (age range 39.88). The data were analysed using specific software & non-parametric ten to assess possible differences in the sleep and 24.hour activity of patients, carers and controls. Patients had significantly higher sleep fragmentation scores than carers and control\ (Chi square 7.17. df2. p
pg
QUALITY OF LIFE OF PEOPLE WITH DEMENTIA AND fHEIR INFORMAL CAREGIVERS
Aa ways of treating people with dementia are developed. researchers need sound methods for evaluating what effect different drugs, therapies and services have on changing individuals’ lives, specifically their ‘quality of life’. Methods of measuring quality of life of people with dementia neglect the perspective of the person with dementia, often because of the challenges to verbal communication. People with dementia and their carers are actively involved in a ‘user group to inform the development of a ‘toolkit’ of outcome measures for assessing quality of life. Active partnerships between people wth dementia and researchers through consultation and collaboration have been developed to empower people with dementia to become more involved in research; to monitor and evaluate the effects of their involvement; and to develop models for identifying and prioritising relevant and appropriate outcomes. The ‘user group’ is exploring exactly how and when members would like to be involved: methods for communicating with people with dementia: identifying and
prioritising topics for further investigation: and is involved in designing and evaluating the content and form of available outcome measures. The ‘user group’ has successfully involved older people with dementia and their carerr in the research process. It has guided the development of research tools, and ensured that the voice of people with dementia is directly incorporated in the research project.
(997(
MEMBRANE INSTABILITY AD.
IN AP-MEDIATED
CELL DEATH IN
Previous stdudies indicate that intracellular accumulatmn of protease-rwatant API-42 aggregatea acts similarly to a class of molecules known aa lysosomotropic detergents. Cell toxicity studies from both AD and lysosomotropic detergent also wggest that the neuronal death invoked by these two compounds is completely pH-dependent since raises in lysosomal pH renderr cell more resi%mt to AP. In addition, the observed dose-dependent cell death occun over a narrow range and at a concentrations similar to the critical rnicelle concentrations of A& supporting that the micelle-like properties of A@ are required for cellular destruction. In this study. we have further indicated that treatment of cultured neurons with AP also causes dose and time-dependent activation of the sphingomyelin hydrolysis cycle and accumulation of ceramide within the degenerating neurons. Since ceramide has hren shown to dramatically reduce the membrane gel-fluid phase transition and promote membrane fusion. we decided to further investigate the consequence of ceramide production on the neuronal endosomalilysosomal system. Our preliminary results show that cultured neurons can uptake NBD-Ch-ceramide through the endocytic pathway and it accumulates in the TGN, where it is converted to sphingomyelin and glycosphingolipids. However, in the presence of AP or lysosomotropic detergents, the trafficking and turnover of NBD-Ch-ceramide from the endosomal vesicle\ to the TGN wa\ completely abolished. Such deficits in sphingoglycolipid hydrolysis further results in the accumulation of enlarged endosomalllysosomal vesicles within the neurons. prior to cell death. Taken together, our results are consistent with the early obxrvations that diaregulation of endosomal/lyaosomaI pathway and changes of membrane Integrity are imponant in early AD pathogenesis.
FE65 REGULATES THE PROCESSING OF THE AMYLOID PRECURSOR PROTEIN (APP)
Alrhenner‘s Diwa\e (A D.) is charactenred by two principal hallmal-k\. the amyloid plaque\ end the ncurofibrillary tanglw Mutatmw identified in barndial tomn ot A.D that atTect the Amylold Precursor Pmtem (APP) and the two presenilins, have an m?pacl on APP processing. wgpeyting that ahnormal proces?inp of APP could he involved in the ethiopathology. FE65 and related proteins as COFEhS/FE65LI and FE6SL2, interact with the cytoplasmic domain of APP. The three polypeptidcs contain three domains involved in protein-protem interaction: two PTB (PhosphoTyrosme Bmding) domain\ and one WW domam. Here we Ehow, in different cellular systems, the role of the FEhS protem family m the regulation of APP processing. Expression of competitors, hke the cytoplasm? domain of APP 01 the PTB2 domain of FE65, lead to a decrease in AP production. In tbesr cellular system\ A0 and the wcretion of the soluble form of APP are regulated in the wme way. suggertmg FE65 regulate5 APP procescing at an early step in the intracellular traficking. These resul[\ aI50 indicate that disturbance of the interaction between APP and FE65 can lcad to an mnovative therapeutic approach of the disease.