Clinical Trial: Isolated Erythrocyte Membrane Susceptibility to Photo-oxidative Stress in Alzheimer's Disease

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Isolated Erythrocyte Membrane Susceptibility to Photo-oxidative Stress in Patients Affected by Alzheimer's Disease and Healthy Controls

Brief Summary:

High lipid peroxidation and altered antioxidant defenses have been frequently reported in Alzheimer's disease patients.

The purpose of this study is to investigate susceptibility to photo-oxidation of isolated erythrocyte membranes, in patients affected by Alzheimer's disease and age- and sex-matched, non demented subjects.


Detailed Summary:

The study hypothesis is that high lipid peroxidation and decreased antioxidant defenses characterize the natural history of Alzheimer's disease.

It will be evaluated the release of malondialdehyde (MDA) from ex-vivo photo-oxidized erythrocyte ghosts, through a very easy and convenient lab procedure for the preparation of erythrocyte membrane samples.

Isolated and purified red blood cell membranes will be in vitro exposed to oxidative stress by UV-B radiation. The extent of cell membrane damage will be quantified by the fluorometric determination of MDA.

Induction of oxidative stress through ultraviolet rays, unlike that obtained by chemical oxidizing agents, is fully controllable, since it produces effects only during irradiation. Moreover, using isolated erythrocyte membranes allows for a greater specificity in the evaluation of MDA produced, and reduces the amount of blood required for the assay.

A portion of the blood sample (500 µL) will be sent to the laboratory of Lipinutragen (spin-off of CNR- National Research Center Bologna, Italy) where an erythrocyte membrane lipidomic analysis will be performed for the characterization of membrane phospholipids, in order to determinate the different lipid components (saturated fatty acids, monounsaturated and polyunsaturated, trans fatty acids), each one characterized by a different oxidative reactivity.

Recently published papers showed a striking association between urinary excretion of cortisol and the increase of some markers of oxidative damage of DNA and RNA (in humans). This finding provides further support to the idea that chronic psychological stress, who is associated to hypercortisolemia, can lead to an acceleration
Sponsor: Raffaele Antonelli Incalzi

Current Primary Outcome: Malondialdehyde assay [ Time Frame: At the time of recruitment ]

Isolated and purified red blood cell membranes will be in vitro exposed to oxidative stress by UV-B radiation. The extent of cell membrane damage will be quantified by the fluorometric determination of malondialdehyde.


Original Primary Outcome: Same as current

Current Secondary Outcome: Relationship between urinary excretion of cortisol and levels of malondialdehyde [ Time Frame: At the time of recruitment ]

Hyperactivity of the hypothalamic pituitary adrenal axis has been frequently described in Alzheimer's disease. Recently published work reported an association between high secretion of cortisol and oxidative stress. We will investigate the relationship between 24 h excretion of urinary cortisol and the level of malondialdehyde, produced by isolated and purified red blood cell membranes, in vitro exposed to oxidative stress by UV-B radiation.


Original Secondary Outcome: Same as current

Information By: Campus Bio-Medico University

Dates:
Date Received: October 1, 2012
Date Started: June 2015
Date Completion: January 2017
Last Updated: March 31, 2016
Last Verified: March 2016