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P2–021: Aberrant calcium signaling modulates inflammatory and PI3/Akt pathways in Alzheimer's disease
Author(s) -
Afanador Lauriasella,
Keeling David,
Campbell Kerry,
Campbell Katie,
Roltsch Emily,
Zimmer Danna
Publication year - 2013
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2013.05.663
Subject(s) - protein kinase b , microbiology and biotechnology , astrocytosis , calcium signaling , biology , signal transduction , phosphorylation , pi3k/akt/mtor pathway , neuroscience , central nervous system
Background: Human cerebrospinal fluid (CSF), produced by the choroid plexus and secreted into the brain ventricles and subarachnoid space, plays critical roles in intra-cerebral transport and the biophysical and immune protection of the central nervous system (CNS). CSF composition provides valuable insight into soluble pathogenic bio-markers that may be diagnostic for neurodegenerative disease. In these experiments we analyzed amyloid beta (Ab) peptide and micro RNA (miRNA) abundance (i) in CSF, (ii) in short post-mortem interval brain tissue-derived extracellular fluid (ECF) and (iii) in brain tissue biopsy derived from Alzheimer’s disease (AD) or age-matched control neocortex and/or hippocampal CA1.Methods: 3’-untranslated region (3’-UTR) sequence/vector analysis; Ab42-peptide+TNFainduced and/or hydrogen peroxide-induced stress; bioinformatics; CAPE, CAY10512, DNA array; DNA/RNA sequencing; human brain biopsy/postmortem tissue; human CSF;LED-Northern micro-dot blot analysis; microRNA array; protected anti-miRNAs; RT-PCR; statistical analysis, b-actin, TREM-2and CFH-3’-UTR-luciferase-reporter transfection assay; UV/ fluorescent microscopy; Western immuno-histochemistry. Results: There was a trend for decreased-abundance of Ab42 in the CSF and ECF in AD but it did not reach statistical significance (mean-age w72 yr; N1⁄412; pw0.06, ANOVA).The most abundant nucleic acids in AD-CSF and ECF were miRNAs and their speciation, abundance and inducibility were studied further. Comparison ofmiRNA signals between biopsy and post-mortem tissues (0.5-6 hrs) indicated a short half-life for many brain-enriched miRNAs. Fluorescent miRNA-array-based analysis indicated significant increases in miRNA-9, miRNA-34a, miRNA-125b, miRNA-146a and miRNA-155. Increases in miRNAs were confirmed independently using a highly-sensitive LED-Northern dot-blot assay. Primary human neuronal-glial cell co-cultures stressed with AD-derived ECF, TNFa or peroxide also displayed an up-regulation of these and other miRNAs. These effects were quenched using the anti-NF-LB agents caffeic acid-phenethyl-ester (CAPE) or 1-fluoro2-[2-(4-methoxy-phenyl)-ethenyl]-benzene (CAY10512). Conclusions: The results indicate that miRNA-9, miRNA-34a, miRNA-125b, miRNA146a and miRNA-155 are a family of inducible, NF-LB-sensitive pro-inflammatory miRNAs that are abundant in AD tissues and fluids. These AD-upregulated miRNAs further associate with deficits in the innate-immune response and the chronic and progressive spreading of inflammatory neurodegeneration. Enrichment of these miRNAs in circulating CSF and ECF suggest that they may be involved in the proliferation of miRNA-triggered pathogenic signaling throughout the AD brain and CNS.