Differentiated Embryonic Neurospheres from Familial Alzheimer's Disease Model Show Innate Immune and Glial Cell Responses.

Proteins involved in the Alzheimer's disease (AD), such as amyloid precursor protein (APP) and presenilin-1 (PS1), play critical roles in early development of the central nervous system (CNS), as well as in innate immune and glial cell responses. Familial AD is associated with the presence of APP and PS1 mutations. However, it is still unknown whether these mutations cause deficits in CNS development of carriers. We studied genome-wide gene expression profiles of differentiated neural progenitor cells (NPCs) from wild-type and APPPS1 mouse embryo telencephalon. The occurrence of strong innate immune and glial cell responses in APPPS1 neurospheres mainly involves microglial activation, inflammatory mediators and chemokines. APPPS1 neurospheres augmented up to 100-fold CCL12, CCL5, CCL3, C3, CX3CR1, TLR2 and TNF-alpha expression levels, when compared to WT neurospheres. Expression levels of the glia cell marker GFAP and microglia marker Iba-1 were up to 20-fold upregulated in APPPS1 neurospheres. The secretome of differentiated APPPS1 NPCs revealed enhanced chemoattraction of peripheral blood mononuclear cells. When evaluating the inferred protein interaction networks constructed from the array data, an improvement in astrocyte differentiation in APP/PS1 neurospheres was evident in view of increased GFAP expression. Transgenic NPCs differentiated into neural phenotypes presented expression patterns of cytokine, glial cells, and inflammatory mediators characteristic of APPPS1 adult animals. Consequently, the neurogenic niche obtained from differentiation of embryonic APPPS1 neurospheres spontaneously presents several alterations observed in adult AD brains. Finally, our data strengthen pathophysiological hypotheses that propose an early neurodevelopmental origin for familial AD.