Impact of SIN-1-derived peroxynitrite flux on endothelial cell redox homeostasis and bioenergetics: protective role of diphenyl diselenide via induction of peroxiredoxins

Abstract

Increased production of reactive nitrogen (RNS) and oxygen (ROS) species and its detrimental effect to mitochondria are associated with endothelial dysfunction. This study was designed to determine the effect of a peroxynitrite flux, promoted by 1,3-morpholinosydnonimine (SIN-1), in mitochondrial function and some redox homeostasis parameters in bovine aortic endothelial cells (BAEC). Moreover, the effect of diphenyl diselenide (PhSe)₂, a simple organic selenium compound, in preventing peroxynitrite-mediated cytotoxicity was also investigated. Our results showed that overnight exposure to SIN-1 (250 μM) caused a profound impairment of oxygen consumption, energy generation and reserve capacity in mitochondria of BAEC. Mitochondrial dysfunction resulted in an additional intracellular production of peroxynitrite, amplifying the phenomenon and leading to changes in redox homeostasis. Moreover, we observed an extensive decline in mitochondrial membrane potential (ΔΨ_m) induced by peroxynitrite and this event was associated with apoptotic-type cell death. Alternatively, the pretreatment of BAEC with (PhSe)₂, hindered peroxynitrite-mediated cell damage by preserving mitochondrial and endothelial function and consequently preventing apoptosis. The protective effect of (PhSe)₂ was related to its ability to improve the intracellular redox state by increasing the expression of different isoforms of peroxiredoxins (Prx–1–3), efficient enzymes in peroxynitrite detoxification.

Keywords::

• endothelial cells
• mitochondria
• SIN-1
• peroxynitrite
• diphenyl diselenide
• nitroxidative stress
• mitochondrial dysfunction
• nitric oxide homeostasis
• apoptosis
• peroxiredoxin

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

This work was supported by grants from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), CAPES/UDELAR Program, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio a Pesquisa do Estado de Santa Catarina (FAPESC), National Institute of Health, 1R01AI095173-01 (NIH, USA) RR; Fondo Clemente Estable FCE_2_2011_1_6363 (ANII, Uruguay).