Modulation of Mouse Embryonic Stem Cell Proliferation and Neural Differentiation by the P2X7 Receptor

Abstract

BackgroundNovel developmental functions have been attributed to the P2X7 receptor (P2X7R) including proliferation stimulation and neural differentiation. Mouse embryonic stem cells (ESC), induced with retinoic acid to neural differentiation, closely assemble processes occurring during neuroectodermal development of the early embryo.Principal FindingsP2X7R expression together with the pluripotency marker Oct-4 was highest in undifferentiated ESC. In undifferentiated cells, the P2X7R agonist Bz-ATP accelerated cell cycle entry, which was blocked by the specific P2X7R inhibitor KN-62. ESC induced to neural differentiation with retinoic acid, reduced Oct-4 and P2X7R expression. P2X7R receptor-promoted intracellular calcium fluxes were obtained at lower Bz-ATP ligand concentrations in undifferentiated and in neural-differentiated cells compared to other studies. The presence of KN-62 led to increased number of cells expressing SSEA-1, Dcx and β3-tubulin, as well as the number of SSEA-1 and β3-tubulin-double-positive cells confirming that onset of neuroectodermal differentiation and neuronal fate determination depends on suppression of P2X7R activity. Moreover, an increase in the number of Ki-67 positive cells in conditions of P2X7R inhibition indicates rescue of progenitors into the cell cycle, augmenting the number of neuroblasts and consequently neurogenesis.ConclusionsIn embryonic cells, P2X7R expression and activity is upregulated, maintaining proliferation, while upon induction to neural differentiation P2X7 receptor expression and activity needs to be suppressed.

Silencing of P2X7R by RNA interference in the hippocampus can attenuate morphological and behavioral impact of pilocarpine-induced epilepsy

“…Similar hypothesis that neurogenesis contributes to worsen seizures was presented previously [86]. P2X7R have been shown to modulate mechanisms involved with apoptosis/necrosis and neuronal differentiation of NPCs [87][88][89][90], while P2Y1 receptors modulate proliferation and migration of NPCs [91][92][93]. Klaft et al [94] also found that P2X7R antagonists had a minor antiepileptic effect in medial entorhinal cortex on rats subjected to pilocarpine-induced epilepsy.…”

Glioblastoma‐mesenchymal stem cell communication modulates expression patterns of kinin receptors: Possible involvement of bradykinin in information flow

“…By the same token, increased levels of kinin receptor expression would not support previously observed inhibition of invasion of GBM cells in indirect interactions with MSC (9). With respect to the underlying mechanism, Montana and Sontheimer (16) showed that bradykinin via B2R-induced [Ca 21 ] i transients enhanced and directed invasion of glioma cells toward blood vessels. Moreover, Seifert and Sontheimer (15) recently revealed that bradykinin through [Ca 21 ] i transients in GBM cells in vitro induced the formation of small bleb-like protrusions at the plasma membrane, which stimulated an amoeboid phenotype of cell migration.…”

Nucleotides and nucleoside signaling in the regulation of the epithelium to mesenchymal transition (EMT)

“…In this context, expression of transcription factors, such as Slug and Sox9, was demonstrated both in CSC and during EMT [108,109]. Purines, through P2X7 receptors, contribute to the maintenance of stemness in embryonic stem cells [110], and they regulate the proliferation rate of cancer stem cells and endothelial progenitors [111]. Further studies are needed to confirm and extend purinergic regulation in CSC biology.…”