TRP Channels Coordinate Ion Signalling in Astroglia

Abstract

Astroglial excitability is based on highly spatio-temporally coordinated fluctuations of intracellular ion concentrations, among which changes in Ca2+ and Na+ take the leading role. Intracellular signals mediated by Ca2+ and Na+ target numerous molecular cascades that control gene expression, energy production and numerous homeostatic functions of astrocytes. Initiation of Ca2+ and Na+ signals relies upon plasmalemmal and intracellular channels that allow fluxes of respective ions down their concentration gradients. Astrocytes express several types of TRP channels of which TRPA1 channels are linked to regulation of functional expression of GABA transporters, whereas TRPV4 channels are activated following osmotic challenges and are up-regulated in ischaemic conditions. Astrocytes also ubiquitously express several isoforms of TRPC channels of which heteromers assembled from TRPC1, 4 and/or 5 subunits that likely act as stretch-activated channels and are linked to store-operated Ca2+ entry. The TRPC channels mediate large Na+ fluxes that are associated with the endoplasmic reticulum Ca2+ signalling machinery and hence coordinate Na+ and Ca2+ signalling in astroglia.

Transient Receptor Potential Channels as Drug Targets: From the Science of Basic Research to the Art of Medicine

“…In addition to neurons, TRPV1 expression was also described in astrocytes (Doly et al, 2004;Verkhratsky et al, 2013). Indeed, the selective TRPV1 agonist RTX was reported to induce Fos expression in astrocytes in wild-type, but not TRPV1 knockout, mice (Mannari et al, 2013).…”

Astroglial calcium signalling in Alzheimer's disease

“…Calcium ions are the most ubiquitous and evolutionary ancient intracellular second messenger that controls various vital cellular functions and regulate physiological responses in virtually every living organism [36][37][38][39][40] [45][46][47]), transient receptor potential (TRP) channels [48,49] and sodium calcium exchanger (NCX), operating in the reverse mode [50]. The TRPC-containing channels [51] also contribute to the store-operated Ca 2+ entry initiated by the depletion of the ER store of releasable Ca 2+ [52,53].…”

P2Y1 Receptor Activation of the TRPV4 Ion Channel Enhances Purinergic Signaling in Satellite Glial Cells

“…Cultured DRG-The expression and function of TRP ion channels has been reported in neurons and glial cell types of the central and peripheral nervous systems (6,33,34). However, TRP channel activity in SGCs has not been investigated in detail.…”