Activation of recombinant human TRPV1 receptors expressed in SH-SY5Y human neuroblastoma cells increases [Ca super(2+)] sub(i), initiates neurotransmitter release and promotes delayed cell death

• Published in: Journal of neurochemistry 2007-08, Vol.102 (3), p.801-811
• Main Authors: Lam, Patricia MW, Hainsworth, Atticus H, Smith, Graham D, Owen, Davina E, Davies, James, Lambert, David G
• Format: Article
• Language: English
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2007.04569.x

The transient receptor potential (TRP) vanilloid receptor subtype 1 (TRPV1) is a ligand-gated, Ca super(2+)-permeable ion channel in the TRP superfamily of channels. We report the establishment of the first neuronal model expressing recombinant human TRPV1 (SH-SY5Y sub(hTRPV1)). SH-SY5Y human neuroblastoma cells were stably transfected with hTRPV1 using the Amaxa Biosystem (hTRPV1 in pIREShyg2 with hygromycin selection). Capsaicin, olvanil, resiniferatoxin and the endocannabinoid anandamide increased [Ca super(2+)] sub(i) with potency (EC sub(50)) values of 2.9 nmolL, 34.7 nmolL, 0.9 nmolL and 4.6 mu molL, respectively. The putative endovanilloid N-arachidonoyl-dopamine increased [Ca super(2+)] sub(i) but this response did not reach a maximum. Capsaicin, anandamide, resiniferatoxin and olvanil mediated increases in [Ca super(2+)] sub(i) were inhibited by the TRPV1 antagonists capsazepine and iodo-resiniferatoxin with potencies (K sub(B)) of similar to 70 nmolL and 2 nmolL, respectively. Capsaicin stimulated the release of pre-labelled [ super(3)H]noradrenaline from monolayers of SH-SY5Y sub(hTRPV1) cells with an EC sub(50) of 0.6 nmolL indicating amplification between [Ca super(2+)] sub(i) and release. In a perfusion system, we simultaneously measured [ super(3)H]noradrenaline release and [Ca super(2+)] sub(i) and observed that increased [Ca super(2+)] sub(i) preceded transmitter release. Capsaicin treatment also produced a cytotoxic response (EC sub(50) 155 nmolL) that was antagonist-sensitive and mirrored the [Ca super(2+)] sub(I) response. This model displays pharmacology consistent with TRPV1 heterologously expressed in standard non-neuronal cells and native neuronal cultures. The advantage of SH-SY5Y sub(hTRPV1) is the ability of hTRPV1 to couple to neuronal biochemical machinery and produce large quantities of cells.