Nitro-oleic acid (NO₂-OA), pluripotent cell-signaling mediator, was recently described as a modulator of the signal transducer and activator of transcription 3 (STAT3) activity. In our study, we discovered new aspects of NO₂-OA involvement in the regulation of stem cell pluripotency and differentiation. Murine embryonic stem cells (mESC) or mESC-derived embryoid bodies (EBs) were exposed to NO₂-OA or oleic acid (OA) for selected time periods. Our results showed that NO₂-OA but not OA caused the loss of pluripotency of mESC cultivated in leukemia inhibitory factor (LIF) rich medium via the decrease of pluripotency markers (NANOG, sex-determining region Y-box 1 transcription factor (SOX2), and octamer-binding transcription factor 4 (OCT4)). The effects of NO₂-OA on mESC correlated with reduced phosphorylation of STAT3. Subsequent differentiation led to an increase of the ectodermal marker orthodenticle homolog 2 (Otx2). Similarly, treatment of mESC-derived EBs by NO₂-OA resulted in the up-regulation of both neural markers Nestin and β-Tubulin class III (Tubb3). Interestingly, the expression of cardiac-specific genes and beating of EBs were significantly decreased. In conclusion, NO₂-OA is able to modulate pluripotency of mESC via the regulation of STAT3 phosphorylation. Further, it attenuates cardiac differentiation on the one hand, and on the other hand, it directs mESC into neural fate.

Administration of biological therapy (BT) in rheumatoid arthritis (RA) patients is often associated with hematological complications, which result in switching among therapies. Thus, there is an instant need for suitable screening parameters that will help to individualize the therapy and minimize the onset of adverse effects. We analyzed the hematological profile of 99 RA patients receiving TNFα (Adalimumab - ADA, Golimumab - GOL, Etanercept - ETA) or IL-6 receptor (Tocilizumab - TCZ) inhibitors in order to find possible indicators to improve personalization of RA therapy. BTs significantly affect the levels of observed hematological parameters. In contrast to TNF-α inhibitors, TCZ normalized almost all monitored hematological parameters to values of healthy donors. Only GOL from the TNF-α inhibitors studied, was able to normalize neutrophil counts, as well as platelet indicators. Importantly, effects on the blood parameters (e.g. lymphocytes or platelet count) differ even within the same therapeutic group (anti-TNFα). Variable effects of individual biological agents in RA treatment point to importance to evaluate the patient’s hematological profile to improve the selection of suitable BT. It will help to personalize the administration of BT and prevent unnecessary switching from an effective therapy just because of provocation of avoidable hematological complications.

Nitro-fatty acids (NO₂FAs) are endogenously produced electrophiles and NRF2 activators with therapeutic potential. We developed a synthetic protocol combining a Henry reaction and base-promoted β-elimination, yielding ultrapure regio/stereoisomers of nitro-stearic (NO₂SA), nitro-oleic (NO₂OA), and conjugated/bis-allylic nitro-linoleic (NO₂LA) acids. These were tested for NRF2 pathway activation in bone marrow cells under different oxygen conditions. We observed that 9- and 10-NO₂OA, and 10-NO₂LA increased NRF2 stabilization under hypoxia, while 9- and 10-NO₂OA significantly upregulated Hmox1 and Gclm at all oxygen levels. 9- and 10-NO₂OA enhanced HO-1 and GCLM proteins independently of oxygen, while 10-NO₂LA was oxygen-dependent, boosting HO-1 under hypoxia and GCLM under ambient conditions. Moreover, 10-NO₂OA and 10-NO₂LA induced NRF2 nuclear translocation. In contrast, the saturated 10-NO₂SA, which has lower electron-acceptor ability, was inactive. In summary, these findings suggest the biological activity of NO₂FAs is dependent on oxygen level, which could be used in future research of other oxidative stress-dependent pathways.

Hypoxia, a common feature of head and neck squamous cell carcinoma (HNSCC), significantly compromises radiotherapy efficacy by modulating DNA repair, cell‑cycle progression, and inflammatory signaling pathways. In addition, intrinsic tumor heterogeneity—including tumor origin and human papillomavirus (HPV) oncogene expression—further shapes therapeutic response. Despite these recognized factors, the integrated impact of oxygen tension, tumor origin, and viral oncogene expression on radiation response remains poorly defined. We examined the effects of hypoxia (1% O ₂ ) and gamma-irradiation (6 Gy) on proliferation, cell-cycle progression, apoptosis, transcriptomic profiles, and cytokine secretion in three HNSCC cell lines: FaDu (primary origin), Detroit-562 (metastatic origin), and 2A3, an isogenic FaDu derivative stably expressing HPV-16 E6/E7 oncogenes. Hypoxia prolonged cell doubling time across all lines, independent of origin or E6/E7 expression, while irradiation induced features of an intermediate epithelial–mesenchymal transition phenotype. Compared with FaDu, 2A3 cells exhibited distinct transcriptional responses, reduced cytokine secretion (IL-8, Serpin E1), and altered cell-cycle regulation following irradiation. Detroit-562 cells secreted markedly higher cytokine levels and showed no increase in cleaved caspase-3 under hypoxia after irradiation. Our findings demonstrate that oxygen tension and biological factors—including metastatic origin and E6/E7 expression—modulate radiation response in HNSCC cell lines. These results highlight the need for biomarker-driven strategies that consider both hypoxic tumor microenvironment and key biological factors such as metastatic origin and HPV‑related E6/E7 oncogene expression.

Acute radiation syndrome remains a major consequence of high-dose ionizing radiation exposure, and effective pharmacological countermeasures are limited. Nitro-fatty acids possess anti-inflammatory and cytoprotective properties, suggesting potential effectiveness in radiation injury. Here, we investigated the radioprotective effects of 10-nitro-oleic acid (10-NO₂OA) in mouse models of total body irradiation (TBI). C57BL/6 mice were exposed to either sublethal (4 Gy) or LD ₅₀ -level (7.5 Gy) gamma irradiation and treated with 10-NO₂OA according to pre-irradiation, post-irradiation, or combined treatment regimens. Survival, hematological responses, bone marrow cells (BMCs)/colony-forming units (CFU), plasma granulocyte colony-stimulating factor (G-CSF), NRF2-responsive signaling, and intestinal responses were evaluated. Administration of 10-NO₂OA before and after irradiation significantly improved 30-day survival following 7.5 Gy TBI (57% vs. 20% in vehicle-treated controls). In contrast, post-irradiation treatment alone was ineffective, whereas pre-irradiation treatment alone produced a non-significant trend toward improved survival. The protective effect was absent in BALB/c mice, indicating strain dependence. Although 10-NO₂OA did not prevent long-term radiation-induced cytopenia, it increased neutrophil and platelet counts, elevated plasma G-CSF levels shortly after irradiation, and transiently enhanced BMC counts. In irradiated BMCs, 10-NO₂OA activated NRF2-responsive gene expression in vitro and in vivo . Exploratory intestinal analyses revealed improved macroscopic appearance and partial restoration of irradiation-suppressed cytokine and growth factor production. In conclusion, 10-NO₂OA improves survival following LD ₅₀ -level gamma irradiation and is associated with modulation of hematopoietic, cytoprotective, and intestinal responses. These findings identify 10-NO₂OA as a promising candidate radioprotective agent and support a multifactorial mechanism of action.