Article
Alzheimer’s disease-like changes in calcium associated gene expression and protein regulation following C. pneumoniae infection of neuronal cells and monocytes.
Society for Neuroscience 2012 Annual Meeting
(2012)
Abstract
BACKGROUND
The calcium hypothesis postulates that sustained disturbance of intracellular calcium are the leading cause of neurodegenerative disorders. Studies showing alteration in calcium signaling in both sporadic and familial Alzheimer’s disease (AD) support this hypothesis. Intracellular calcium signaling is tightly regulated and is responsible for a variety of neuronal functions. Calcium influx from the extracellular environment modulates calcium levels, as do intracellular stores in the endoplasmic reticulum. The focus of this study was to evaluate regulation changes in calcium related genes in both monocytes and neuronal cells. Previous studies have shown that Cpn-infected cells exhibit altered protein processing consistent with that observed in AD. As every calcium gene has a unique function in the cell, determining which genes are up or down regulated following infection may provide insight into how the neurodegeneration process observed in AD is initiated by Cpn infections.
METHODS
Using the AR39 strain of Cpn at a MOI of 1, both THP-1 monocytes and SKNMC neuronal cells were infected for 48 hours. Cells were analyzed using Real-time PCR microarrays from SABiosciences for calcium related genes. Protein regulation was evaluated using fast western blotting with three calcium protein antibodies. Monocytes and neuronal cells were also labeled with 61C75 directly conjugated antibody to FITC for verification of infection with Cpn.
RESULTS
Twelve calcium genes with a two fold increase or decrease in Cpn-infected cells were noted. Of the twelve genes, S100 Calcium Binding Protein had the greatest degree of up-regulation ~ 35fold in THP-1 monocytes. Neurofibromin-1 had the highest degree of down-regulation in both THP-1 and SKNMC cells. Chromogranin A was up-regulated two fold in THP-1 cells and down-regulated two fold in SKNMC. In western blot protein analysis, S100A12 was up-regulated in SKNMC cells and showed no protein product in THP-1 monocytes; Neurofibromin-1 was up-regulated in both THP-1 and SKNMC cells; and Chromogranin A was down-regulated in both cell lines. Western blot analysis was confirmed by immunofluorescence for NF-1 and S100A12 in SKMNC neuronal cells.
CONCLUSIONS
Our data suggest that Cpn infection alters calcium-related gene regulation and levels of protein products of at least three calcium genes. These changes may help to maintain an environment beneficial to pathogen survival as well as coincide with alterations in intracellular calcium previously observed in AD. These studies may help to elucidate how Cpn may affect cellular processes that contribute to the pathogenesis seen in AD.
Keywords
- calcium,
- alzheimer's disease,
- gene regulation
Disciplines
Publication Date
October, 2012
DOI
http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=5f4f794b-c458-434c-bffe-fde3a0304a20&cKey=b081ed40-900d-4fcf-b185-7dab172b765c&mKey=%7b70007181-01C9-4DE9-A0A2-EEBFA14CD9F1%7d
Citation Information
Marcus G. Bell, K G Williams, J D Zoga, Susan Hingley, et al.. "Alzheimer’s disease-like changes in calcium associated gene expression and protein regulation following C. pneumoniae infection of neuronal cells and monocytes." Society for Neuroscience 2012 Annual Meeting (2012) Available at: http://works.bepress.com/denah_appelt/64/