7th International Brain Research School, Isparta, Türkiye, 27 Haziran - 03 Temmuz 2022, cilt.14, sa.4, ss.19
Investigation of TRPM2 cation channel activation in PTZ-induced SH-SY5Y cells by
patch-clamp technique: Regulatory role of valproic acid.
Adem AHLATCI1
, Muhammet BEKTAŞ1
, Yasin TÜLÜCE2
, Kenan YILDIZHAN3
1Department of Biophysics, Istanbul Faculty of Medicine, Istanbul University, Istanbul,
Turkey.
2Department of Medical Biology, Faculty of Medicine, Van Yuzuncu Yil University, Van,
Turkey.
3Department of Biophysics, Faculty of Medicine, Van Yuzuncu Yil University, Van, Turkey.
Abstract
Neurotoxicity is the event that neurons are damaged by natural or artificial toxic substances.
Pentylenetetrazole (PTZ) is a neurotoxic substance and is used to produce experimental
neurotoxicity. Transient Receptor Potential Melastatin 2 (TRPM2) Channel is a non-selective
cation channel activated by adenosine diphosphoribose (ADPR), calcium ion (Ca2+) and
reactive oxygen species and nitrogen species. It is inactivated by N-(p-amylcinnamoyl)
anthranilic acid (ACA). Valproic acid (VPA) is a short-chain fatty acid in the chemical structure
of N-dipropyl acetic acid, it is used as various anticonvulsants and mood stabilizers, especially
in psychiatric and neurological cases. Studies have shown that valproic acid blocks voltagegated sodium or calcium channels (Bowden 2003), but its effect on the TRPM2 channel in the
neuron cell line has not yet been clarified.
SH-SY5Y cells were divided into five groups; control, control + ADPR, PTZ (30 µM for 24
hours), VPA (1 mM for 24 hours), and PTZ + VPA (30 µM for 24 hours and 1 mM for 24
hours) (Taskiran et. al., 2021). The patch-clamp technique was used to observe the activation
of the TRPM2 channel and the protective effect of VPA in the neurotoxicity model created by
PTZ. In the study, ADPR was used as an agonist and ACA as an antagonist for TRPM2
stimulation in SH-SY5Y cells (Yıldızhan and Nazıroğlu 2020). The whole-cell mode patchclamp record showed us that in the ADPR-stimulated groups, the intracellular Ca2+ flow was
highest in the PTZ group compared to the other groups. While no intracellular Ca2+ flow was
observed in the VPA group, intracellular Ca2+ flow was significantly inhibited in the PTZ+VPA
group compared to the PTZ group.
In conclusion, in the electrophysiological study using the patch-clamp technique, we observed
that VPA has a regulatory effect on TRPM2 channel currents in PTZ-induced SH-SY5Y cells.