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

Authors:
Lam PM, Hainsworth AH, Smith GD, Owen DE, Davies J, Lambert DG
In:
Source: J Neurochem
Publication Date: (2007)
Issue: 102(3): 801-11
Research Area:
Neurobiology
Cells used in publication:
SH-SY5Y
Species: human
Tissue Origin: brain
Platform:
Nucleofectorâ„¢ I/II/2b
Abstract
The transient receptor potential (TRP) vanilloid receptor subtype 1 (TRPV1) is a ligand-gated, Ca(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(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(2+)](i) with potency (EC(50)) values of 2.9 nmol/L, 34.7 nmol/L, 0.9 nmol/L and 4.6 mumol/L, respectively. The putative endovanilloid N-arachidonoyl-dopamine increased [Ca(2+)](i) but this response did not reach a maximum. Capsaicin, anandamide, resiniferatoxin and olvanil mediated increases in [Ca(2+)](i) were inhibited by the TRPV1 antagonists capsazepine and iodo-resiniferatoxin with potencies (K(B)) of approximately 70 nmol/L and 2 nmol/L, respectively. Capsaicin stimulated the release of pre-labelled [(3)H]noradrenaline from monolayers of SH-SY5Y(hTRPV1) cells with an EC(50) of 0.6 nmol/L indicating amplification between [Ca(2+)](i) and release. In a perfusion system, we simultaneously measured [(3)H]noradrenaline release and [Ca(2+)](i) and observed that increased [Ca(2+)](i) preceded transmitter release. Capsaicin treatment also produced a cytotoxic response (EC(50) 155 nmol/L) that was antagonist-sensitive and mirrored the [Ca(2+)](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(hTRPV1) is the ability of hTRPV1 to couple to neuronal biochemical machinery and produce large quantities of cells.