The potential protective roles of zinc, selenium and glutathione on hypoxia-induced TRPM2 channel activation in transfected HEK293 cells

Abstract

Hypoxia induces cell death through excessive production of reactive oxygen species (ROS) and calcium (Ca²⁺) influx in cells and TRPM2 cation channel is activated by oxidative stress. Zinc (Zn), selenium (Se), and glutathione (GSH) have antioxidant properties in several cells and hypoxia-induced TRPM2 channel activity, ROS and cell death may be inhibited by the Zn, Se, and GSH treatments. We investigated effects of Zn, Se, and GSH on lipid peroxidation (LPO), cell cytotoxicity and death through inhibition of TRPM2 channel activity in transfected HEK293 cells exposed to hypoxia defined as oxygen deficiency.

We induced four groups as normoxia 30 and 60 min evaluated as control groups, hypoxia 30 and 60 min in the HEK293 cells. The cells were separately pre-incubated with extracellular Zn (100 µM), Se (150 nM) and GSH (5 mM). Cytotoxicity was evaluated by lactate dehydrogenase (LDH) release and the LDH and LPO levels were significantly higher in the hypoxia-30 and 60 min-exposed cells according to normoxia 30 and 60 min groups. Furthermore, we found that the LPO and LDH were decreased in the hypoxia-exposed cells after being treated with Zn, Se, and GSH according to the hypoxia groups. Compared to the normoxia groups, the current densities of TRPM2 channel were increased in the hypoxia-exposed cells by the hypoxia applications, while the same values were decreased in the treatment of Zn, Se, and GSH according to hypoxia group. In conclusion, hypoxia-induced TRPM2 channel activity, ROS and cell death were recovered by the Se, Zn and GSH treatments.

Keywords:

• Hypoxia
• TRPM2 channel
• HEK293
• Zn
• Se

Acknowledgement

The study was carried out at Patch Clamp Laboratory, Cell Culture Laboratory, and Blood Gas Measurement Laboratory at Department of Biophysics, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, and Department of Genetic, Aziz Sancar Institute of Experimental Medicine, Istanbul University. This study was presented as an oral presentation at 7th World Congress of Oxidative Stress, Calcium Signaling and TRP Channels, 20 and 23 April 2018, Alanya, Turkey (http://2018.cmos.org.tr/)

Author contributions

SD designed the study and developed the theory. D.D.E. performed the majority of the experiments, analyzed the data, and wrote the manuscript. N.P.O. contributed to the planning and execution of experiments. O.H.N. shared to experiments. SD, D.O., and M.N. supervised the whole experimental work and revised the manuscript. All authors provided critical feedback and helped shape the research, analysis, and manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Additional information

Funding

The present work was supported by the Research Fund of Istanbul University. Project No: 50309.