Curcumin inhibits oxidative stress-induced TRPM2 channel activation, calcium ion entry and apoptosis values in SH-SY5Y neuroblastoma cells: Involvement of transfection procedure

Abstract

Transient Receptor Potential (TRP) channels are mostly Ca²⁺ permeable cation channels. Transient Receptor Potential Melastatin-like 2 (TRPM2) is expressed in neurological tissues such as brain, dorsal root ganglia (DRG) neurons, hippocampus and also liver, heart and kidney. The SH-SY5Y cells are mostly used as a cellular model of neurodegenerative diseases, Alzheimer's and Parkinson's diseases. Curcumin, shows phenolic structure, synthesized by Curcuma longa L. (turmeric), has powerful non-enzymatically antioxidant effects compared with Vitamin E. Hence, we aimed to investigate that effects of curcumin on TRPM2 cation channel currents using the whole-cell Patch-Clamp method, Ca²⁺ signaling, apoptosis and cell viability (MTT) assays, reactive oxygen species (ROS) production, mitochondrial membrane potential levels, caspase 3 and caspase 9 activities in TRPM2 transfected SH-SY5Y neuroblastoma cells. For this aim, we designed four experimental groups named; control, curcumin, transfected and transfected + curcumin groups. Cytosolic free calcium concentrations were higher in transfected group compared with curcumin and transfected + curcumin group. Moreover, these data examined with whole-cell Patch-Clamp recordings of single cells in all groups. ROS levels were significantly higher in transfected group than in transfected + curcumin group. Apoptosis levels in transfected + curcumin group were lower than in transfected group. Procaspase 9 and procaspase 3 levels measured by western blotting and caspase 3 and caspase 9 levels by spectrophotometric methods show that TRPM2 transfected cells are more tended to apoptosis. In conclusion, curcumin strongly induces modulator effects on TRPM2-mediated Ca²⁺ influx caused by ROS and caspase 3 and 9 processes in SH-SY5Y neuroblastoma cells.

Keywords:

• TRPM2 channels
• Patch-Clamp
• Ca²⁺ signaling
• curcumin
• SH-SY5Y cells

Disclosure statement

The authors Ahmi ÖZ and Ömer ÇELİK declare that they have no conflicts of interest.

Additional information

Funding

The study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Project Number: 215S043) and partially supported by Coordination Unit of Academic Stuff Development Program (ÖYP), Süleyman Demirel University, Isparta, Turkey (Project Number: ÖYP6164-YL-13).