Proper functioning of the endothelial barrier is crucial for cardiovascular system homeostasis. Oxidative stress can lead to endothelial dysfunction (ED), damaging lipids, proteins, and DNA. Reactive oxygen species also increase cytoplasmic Ca²⁺ levels, activating transient receptor potential melastatin 2 (TRPM2), a membrane non-selective calcium channel. The study aimed to assess TRPM2's significance in vascular endothelial cells' response to oxidative stress and the potential use of TRPM2 direct and indirect inhibitors in the prevention of oxidative stress-induced ED.

EA.hy926 endothelial cells were exposed to hydrogen peroxide for 24??h to mimic oxidative stress conditions. To assess the significance of TRPM2 in the response of EA.hy926??cells to hydrogen peroxide TRPM2 siRNA as well as direct (N-(p-Amylcinnamoyl)anthranilic acid, flufenamic acid) and indirect (3-aminobenzamide, 3,4-dihydro-5[4-(1-piperidinyl)butyl]-1(2H)-isoquinolinone) TRPM2 inhibitors were tested.

Results showed that hydrogen peroxide-induced ED is alleviated by TRPM2 downregulation. Moreover, preincubation of cells with both direct and indirect TRPM2 inhibitors for 30??min before hydrogen peroxide treatment reduces its negative effects on cell viability, cell migration, and junctional proteins.

The obtained results suggest that TRPM2 channel may be a potential target in therapy and prevention of cardiovascular diseases connected with oxidative stress-induced ED. However, further research is needed for clinical applications of direct and indirect TRPM2 inhibitors.