OBJECTIVES: Our previous studies have demonstrated that the Damage Associated Molecular Pattern (DAMP) protein, S100A4, is overexpressed in the involved skin and peripheral blood of patients with SSc. It is associated with skin and lung involvement, and disease activity. By contrast, lack of S100A4 prevented the development of experimental dermal fibrosis. Herein we aimed to evaluate the effect of murine anti-S100A4 mAb 6B12 in the treatment of preestablished experimental dermal fibrosis. METHODS: The effects of 6B12 were assessed at therapeutic dosages in a modified bleomycin-induced dermal fibrosis mouse model by evaluating fibrotic (dermal thickness, proliferation of myofibroblasts, hydroxyproline content, phosphorylated Smad3-positive cell count) and inflammatory (leukocytes infiltrating the lesional skin, systemic levels of selected cytokines and chemokines) outcomes, and transcriptional profiling (RNA sequencing). RESULTS: Treatment with 7.5 mg/kg 6B12 attenuated and might even reduce pre-existing dermal fibrosis induced by bleomycin as evidenced by reduction in dermal thickness, myofibroblast count and collagen content. These antifibrotic effects were mediated by the downregulation of TGF-β/Smad signalling and partially by reducing the number of leukocytes infiltrating the lesional skin and decrease in the systemic levels of IL-1α, eotaxin, CCL2 and CCL5. Moreover, transcriptional profiling demonstrated that 7.5 mg/kg 6B12 also modulated several profibrotic and proinflammatory processes relevant to the pathogenesis of SSc. CONCLUSION: Targeting S100A4 by the 6B12 mAb demonstrated potent antifibrotic and anti-inflammatory effects on bleomycin-induced dermal fibrosis and provided further evidence for the vital role of S100A4 in the pathophysiology of SSc.

• Keywords
• 6B12, S100A4, SSc, established dermal fibrosis, monoclonal antibody, treatment,
• MeSH
• Alarmins * MeSH
• Bleomycin toxicity   MeSH
• Fibrosis MeSH
• Skin * pathology   MeSH
• Humans MeSH
• Disease Models, Animal MeSH
• Antibodies, Monoclonal pharmacology   MeSH
• Mice MeSH
• S100 Calcium-Binding Protein A4 genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alarmins * MeSH
• Bleomycin MeSH
• Antibodies, Monoclonal MeSH
• S100 Calcium-Binding Protein A4 MeSH
• S100A4 protein, human MeSH Browser

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.

• Keywords
• STAT3, cardiomyogenesis, mouse embryonic stem cells, neurogenesis, nitro-oleic acid, pluripotency,
• MeSH
• Biomarkers metabolism   MeSH
• Cell Differentiation * drug effects   MeSH
• Nitro Compounds pharmacology   MeSH
• Embryoid Bodies drug effects   metabolism   MeSH
• Myocytes, Cardiac drug effects   metabolism   MeSH
• Oleic Acids pharmacology   MeSH
• Mouse Embryonic Stem Cells cytology   drug effects   metabolism   MeSH
• Mice MeSH
• Neurons cytology   drug effects   metabolism   MeSH
• Organogenesis drug effects   MeSH
• Pluripotent Stem Cells drug effects   metabolism   MeSH
• Signal Transduction drug effects   MeSH
• STAT3 Transcription Factor metabolism   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Biomarkers MeSH
• CXA-10 MeSH Browser
• Nitro Compounds MeSH
• Oleic Acids MeSH
• STAT3 Transcription Factor MeSH