Neuroprotection by nicotine against hypoxia-induced apoptosis in cortical cultures involves activation of multiple nicotinic acetylcholine receptor subtypes.
Activation of neuronal nicotinic acetylcholine receptors (nAChR) by nicotine has been suggested to protect neurons against a hypoxic insult. The objective of this study was to examine the nature of cell death induced by acute hypoxia in rat primary cortical cultures and the neuroprotective potential of nicotine in ameliorating these processes. Neuronal cell death induced by a 4-h exposure to hypoxia (0.1% O(2)) was apoptotic, as shown by TUNEL staining and assays monitoring DNA strand breaks and caspase-3/7 activity. The presence of nicotine (10 microM) during the hypoxic insult protected a subpopulation of susceptible neurones against DNA damage and apoptosis induced by oxygen deprivation. This protective effect of nicotine was prevented by a 30-min pre-incubation with either 100 nM alpha-bungarotoxin or 1 microM dihydro-beta-erythroidine, but not 1 microM atropine, suggesting that activation of at least two subtypes of nAChR, alpha7 and beta2* nAChR, is involved in mediating nicotine neuroprotection.
Hejmadi
M V
MV
Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK. M.V.Hejmadi@bath.ac.uk
Dajas-Bailador
F
F
Barns
S M
SM
Jones
B
B
Wonnacott
S
S
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002038:Bungarotoxins / Q000494:pharmacology; D015687:Cell Hypoxia / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D004249:DNA Damage / Q000187:drug effects / Q000502:physiology; D004079:Dihydro-beta-Erythroidine / Q000494:pharmacology; D020925:Hypoxia-Ischemia, Brain / Q000188:drug therapy / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000187:drug effects* / Q000378:metabolism; D064569:alpha7 Nicotinic Acetylcholine Receptor
D002038:Bungarotoxins; D004079:Dihydro-beta-Erythroidine; D018696:Neuroprotective Agents; D009538:Nicotine; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; C579165:Chrna7 protein, rat