20 research outputs found

    Aluminium blunts the proliferative response and increases apoptosis of cultured human cells: putative relationship to alzheimer's disease

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    Aluminium (Al) has been investigated as a neurotoxic substance. Al ranks among the potential environmental risk factors for Alzheimer's disease (AD). Epidemiological studies tested the relationship between Al in drinking water and AD, showing a significant correlation between elevated levels of monomeric Al in water and AD, although data to date remain inconclusive with respect to total Al. The aim of this study was to test whether or not Al exacerbates cellular toxicity mediated by the amyloid β (Aβ) peptide. We evaluated the role of Al in modulating programmed cell death (apoptosis) in human cell cultures. We used the osteosarcoma cell line monolayer (SaOs-2) to demonstrate that treatment of SaOs-2 cultures with the Aβ peptide mid-fragment (25 to 35) at nano M, followed by co-incubation with physiological concentrations of aluminium chloride, which release monomeric Al in solution, led to marked expression of caspase 3, but not caspase 9, key markers of the apoptotic process. The same experimental conditions were shown to blunt significantly the proliferative response of normal human peripheral blood mononuclear cells (PBMC) to phytohemagglutinin (PHA) stimulation. Our observations support the hypothesis that Al significantly impairs certain cellular immune responses, and confirm that Al-mediated cell toxicity may play an important role in AD

    Physiologic modulation of natural killer cell activity as an index of Alzheimer's disease progression

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    Patients with Alzheimer's disease (AD) are characterized by an altered sensitivity to cortisol-mediated modulation of circulating lymphocytes. Longitudinal studies are needed to address the clinical applicability of these abnormalities as prognostic factors. Therefore, we designed a longitudinal study to address the clinical applicability of physiologic modulation of Natural Killer (NK) cell activity as a prognostic factor in AD. NK activity was assessed as baseline measurement and in response to modulation by cortisol at 10-6M. To verify the immunophysiological integrity of the NK cell population, we tested augmentation of NK cytotoxicity by human recombinant interleukin (IL)-2 (100 IU/ml) as control. The response to modulation by cortisol or by IL-2 was significantly greater in patients with AD. Based on change in the Mini-Mental State score at entry and at 18 months, patients with AD could be assigned to a “fast progression” (Δ > 2 points) or to a “slow progression” group (Δ ≤ 2 points). The change in the response of NK cytotoxic activity to cortisol, and the strength of the association of this parameter with circulating activated T cells in time was greater in patients with Fast Progression vs. Slow Progression AD. These results suggest that changes in the response of NK cells to negative (e.g., cortisol) or positive modifiers (e.g., IL-2) follow progression of AD

    Neuroendocrine immunity in patients with Alzheimer's disease: toward translational epigenetics

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    The emerging domain of epigenetics in molecular medicine finds application for a variety of patient populations. Here, we present fundamental neuroendocrine immune evidence obtained in patients with senile dementia of the Alzheimer's type (sDAT), and discuss the implications of these data from the viewpoint of translational epigenetics of Alzheimer's disease. We followed 18 subjects with mild sDAT treated with acetylcholinesterase inhibitors, and 10 control subjects matched for age in a repeated measure design every six months for 18 months. We monitored psychosocial profile (Mini-Mental State Examination, Functional Assessment Staging, Independence in Activities of Daily Living, Depression, Profile of Moods States) in parallel to immunophenotypic parameters of T cell subpopulations by flow cytometry. Based on change in the mini-mental state score at entry and at 18 months, patients with sDAT were assigned to a “fast progression” (delta greater than 2 points) or to a “slow progression” group (delta less than or equal to 2 points). The change in circulating activated T cells (CD3+Dr+) with time in patients with sDAT was significantly inversely correlated with the change in time in natural killer (NK) cytotoxic activity to cortisol modulation in these patients, which was greater in patients with fast progression, compared to slow progression sDAT. These data indicate underlying neuroendocrine immune processes during progression of sDAT. Our observations suggest that psychoimmune measures such as those we have monitored in this study provide relevant information about the evolving physiological modulation in patients with sDAT during progression of Alzheimer's disease, and point to new or improved translational epigenetic treatment interventions
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