title: Intracellular calcium handling in rat olfactory ensheathing cells and its role in axonal regeneration.
abstract: Intracellular calcium handling by rat olfactory ensheathing cells (OECs) is implicated in their support for regrowth of adult CNS neurites in a coculture model of axonal regeneration. Pretreatment of OECs with BAPTA-AM to sequester glial intracellular calcium ([Ca(2+)](i)) reduces significantly the numbers of cocultured neurons regrowing neurites. The mean resting [Ca(2+)](i) of OECs cultured alone or with neurons was 300 nM in an external solution containing 2.5 mM calcium ([Ca(2+)](o)). In high [K(+)](o) or zero [Ca(2+)](o), resting [Ca(2+)](i) significantly decreased. [Ca(2+)](i) significantly increased when [Ca(2+)](o) was increased to 20 mM, lonomycin, thapsigargin, and thimerosal increased [Ca(2+)](i), and caffeine, ryanodine, and cyclopiazonic acid were without effect. Of the receptor agonists tested, none induced a change in [Ca(2+)](i). The calcium influx induced by high [Ca(2+)](o) was blocked by La(3+) and SKF96365, partially inhibited by Cd(2+), and insensitive to Ni(2+) and nifedipine. Pretreatment of OECs with La(3+) reduced neurite regrowth in cocultures in a concentration-dependent manner over the range that blocked the non-voltage-gated calcium flux through a putative TRP-like channel, which, we propose, is activated in OEC-mediated axonal regeneration.
authors.affiliation: Neural Damage and Repair GroupCentre for Neuroscience Research, King's College London, Guys Campus, SE1 1UL, London, UK
authors.forename: Shaista
authors.initials: S
authors.lastname: Hayat
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Wigley
authors.forename: Jon
authors.initials: J
authors.lastname: Robbins
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D018920:Coculture Techniques; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D007811:Lanthanum / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology; D009416:Nerve Regeneration / Q000187:drug effects / Q000502:physiology*; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism*; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D050052:TRPC Cation Channels
chemical_list: D015220:Calcium Channels; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D008670:Metals; D050052:TRPC Cation Channels; D007811:Lanthanum; D002118:Calcium