Nucleotide transmitters ATP and ADP mediate intercellular calcium wave communication via P2Y12/13 receptors among BV-2 microglia

Abstract

Nerve injury is accompanied by a liberation of diverse nucleotides, some of which act as ‘find/eat-me’ signals in mediating neuron-glial interplay. Intercellular Ca2+ wave (ICW) communication is the main approach by which glial cells interact and coordinate with each other to execute immune defense. However, the detailed mechanisms on how these nucleotides participate in ICW communication remain largely unclear. In the present work, we employed a mechanical stimulus to an individual BV-2 microglia to simulate localized injury. Remarkable ICW propagation was observed no matter whether calcium was in the environment or not. Apyrase (ATP/ADP-hydrolyzing enzyme), suramin (broad-spectrum P2 receptor antagonist), 2-APB (IP3 receptor blocker) and thapsigargin (endoplasmic reticulum calcium pump inhibitor) potently inhibited these ICWs, respectively, indicating the dependence of nucleotide signals and P2Y receptors. Then, we detected the involvement of five naturally occurring nucleotides (ATP, ADP, UTP, UDP and UDP-glucose) by desensitizing receptors. Results showed that desensitization with ATP and ADP could block ICW propagation in a dose-dependent manner, whereas other nucleotides had little effect. Meanwhile, the expression of P2Y receptors in BV-2 microglia was identified and their contributions were analyzed, from which we suggested P2Y12/13 receptors activation mostly contributed to ICWs. Besides, we estimated that extracellular ATP and ADP concentration sensed by BV-2 microglia was about 0.3 μM during ICWs by analyzing calcium dynamic characteristics. Taken together, these results demonstrated that the nucleotides ATP and ADP were predominant signal transmitters in mechanical stimulation-induced ICW communication through acting on P2Y12/13 receptors in BV-2 microglia.

Interleukin 4 modulates microglia homeostasis and attenuates the early slowly progressive phase of amyotrophic lateral sclerosis

“…7i, j ). P2ry13 is a G protein-coupled nucleotide receptors involved in microglia activation 69 . It was highly expressed by adult GFP-LV microglia, while IL-4 significantly dampened its expression levels in both IL-4-LV and G93A-IL-4-LV mice (Fig.…”

A Neuron–Glial Perspective for Computational Neuroscience

“…The propagation of intercellular Ca 2+ waves in astrocyte networks has been observed in the cortex (Nimmerjahn et al, 2004), the hippocampus (Kuga et al, 2011), the retina (Newman, 2001), or the cerebellum (Hoogland et al, 2009). Ca 2+ waves could as well occur in microglia and oligodendrocytes either independently (Takeda et al, 1995;Wu et al, 2013;Jiang et al, 2017) or in interaction with astrocytes (Verderio and Matteoli, 2001;Schipke et al, 2002;Parys et al, 2010).…”

Three‐dimensional imaging and quantification of real‐time cytosolic calcium oscillations in microglial cells cultured on electrospun matrices using laser scanning confocal microscopy

“…Although ATP has been previously shown to induce a persistent increase in intracellular calcium in microglial cells through activation of the P2X 7 receptor (Eichhoff et al, 2011; Verderio & Matteoli, 2001), these studies were conducted either in vivo or using primary co‐cultures in vitro, wherein the presence of auxiliary cells could have induced additional effects. In contrast, pure microglial cultures are known to either show transient increases in calcium levels or lowered calcium levels in presence of ATP (Jiang et al, 2017; Verderio & Matteoli, 2001). These results are consistent with ATP‐induced lowering of amplitude observed in the present study.…”