LAUSR

Nitro-fatty acids (NO2-FA) are pluripotent signaling molecules endogenously generated as an adaptive response of organism to oxidative and nitrative stress. Recently, we have discovered some new aspects of NO2-FA functions in regulation of stem cell differentiation, showing their high potential as pleiotropic signaling molecules in different cell types. The main aim of this study was to evaluate a potential role of nitro-oleic acid (NO2-OA) in stem cell differentiation under several conditions. Murine embryonic stem cells (ESC) were cultivated in medium with or without leukemia inhibitory factor (LIF) and in the presence of different concentration of fetal bovine serum. The cells were exposed to NO2-OA or oleic acid (OA) for selected time periods (15 min – 72 h) where we monitored several outputs. We have analyzed basic functions of ESC by investigating cell viability, proliferation, and expression of stemness genes and proteins (e.g. oct4, nanog, klf4, brachyury, hnf4a, and otx2) as well as activation of intracellular signaling cascades (e.g. MAPKs, NFκ-B, and STATs), crucially involved in the process of ESC differentiation. Our results showed that physiologically relevant concentrations of NO2-OA induced the differentiation of ESC cultivated in LIF rich medium. The concentration of FBS did not affect the expression of stemness genes or proteins. Interestingly, the effect of NO2-OA on ESC was mediated via reduced phosphorylation of STAT3, which is critically involved in maintenance of stemness in ESC.