Nicotinamide mononucleotide ameliorates DNFB-induced atopic dermatitis-like symptoms in mice by blocking activation of ROS-mediated JAK2/STAT5 signaling pathway

Background and purpose Atopic dermatitis (AD) is a chronic inflammatory skin disease, characterized by pruritus and impaired skin barrier function. The pathology of AD involves in immune dysfunction and epidermal barrier disruption. Reactive oxygen species (ROS) are found to be associated with AD, and play a role in the immunological abnormalities and dysfunctional skin barrier. Nicotinamide mononucleotide (NMN) plays an important role in oxidative stress related diseases, but its role in AD is unclear. Methods KM mice were treated with DNFB to induce AD-like lesion and typical applied with NMN for two weeks. The dermatitis score, the degree of itching and TEWL were evaluated during modeling. Epidermal thickness of skin lesions and histopathological changes were detected. Further, inflammatory factors, epidermal differentiation-related genes, oxidative stress indicators and JAK2/STAT5 signaling pathway were evaluated. NHEK cells were stimulated by TNF-α/IFN-γ after pre-treatment with NMN, then ROS levels, inflammatory factors and JAK2/STAT5 signaling pathway were detected. Results NMN exhibited potent anti-atopic activities, shown by alleviated AD-like symptoms, inhibited the increased expression of inflammatory cytokines and restored proteins and mRNA level of skin barrier genes. In addition, NMN inhibited TNF-α/IFN-γ-stimulated elevation of inflammatory chemokines, which was associated with blocking the activation of ROS-mediated JAK2/STAT5 pathway. Conclusion NMN may have a positive effect on relieving symptoms of AD.