Protective Effects of Recombined Mussel Adhesive Protein against AD Skin Inflammation in Mice

(1) Background: Atopic dermatitis (AD) is characterized as a chronic inflammatory skin disease with a significant incidence rate. The pathophysiological mechanisms underlying AD remain incompletely understood. However, extensive research demonstrates that a complex interplay among genetic, immune, and environmental factors contributes to the disruption of skin barrier function. Inflammation is identified as one of the pathological mechanisms in AD. Recombined mussel adhesive protein exhibits anti-inflammatory properties. However, recombinant mussel adhesive protein has been used less frequently for AD, so we explored the therapeutic effect of recombinant mussel adhesive protein for AD and the potential mechanism. (2) Methods: We established a mice model of AD in vivo and an LPS-induced inflammation model in HaCaT cells in vitro. Through assessment of skin lesion scores, itch frequency, transepidermal water loss, skin microcirculation, HE staining, Elisa assays for IL-6, IL-12, IL-13, IL-4, IL-5, IFN-γ, IgE, and TNF-α, immunohistochemical staining for filaggrin and CK14, Masson staining, and Western blot analysis of NF-κB p65, P-P65, Keap1, and Nrf2, the effects of recombined mussel adhesive protein on AD symptoms, pathology, inflammation, and its mechanisms are investigated. (3) Results: The recombined mussel adhesive protein significantly improved the compromised skin barrier, reduced scratching frequency in mice, decreased transepidermal water loss, and lowered the expression of inflammatory factors, thus ameliorating skin inflammation damage. Mechanistically, recombined mussel adhesive protein downregulated the expression of P-p65/p65 and Keap1 while upregulating the level of Nrf2. (4) Conclusions: Overall, our results demonstrate the effectiveness of recombined mussel adhesive protein in attenuating DNFB-induced AD by inhibiting NF-κB and activating the Keap1/Nrf2 signaling pathway. Thus, recombined mussel adhesive protein is a promising therapeutic candidate for the treatment of AD.