Adipokines-enriched adipose extract restores skin barrier and ameliorates inflammatory dysregulation in an atopic dermatitis mouse model.

Abstract

Atopic dermatitis (AD) is a chronic dermatosis with high incidence worldwide characterized by skin barrier abnormalities and immune dysregulation. Conventional therapies are usually limited by side effects and high cost. Given the anti-inflammatory and repairing properties, adipokines are increasingly considered as promising therapeutic agents for dermatoses. Adipose collagen fragments (ACF), a novel adipokine-enriched product, may alleviate AD through modulating immune microenvironment and restoring skin barrier. ACF was extracted from adipose tissue via high-speed homogenization (10000 rpm/min, 1min) and centrifugation (3000 g, 3min). Ovalbumin-induced AD female BALB/c mice (6-week-old) were intradermally injected with 0.2ml of ACF or PBS (negative control), with normal mice being set as normal control (n=6). Dermatitis severity, inflammatory metrics (epidermal thickness, infiltrated mast cells, Th-type cytokines expression), and skin barrier-related metrics (transepidermal water loss [TEWL], skin barrier-related proteins expression) were evaluated after the AD induction period (day 50). ACF-derived bioactive components were also evaluated using proteomic analysis. ACF-derived adipokines contained anti-inflammatory, skin barrier- and lipid biosynthesis-related components. ACF treatment decreased dermatitis severity (6.2±1.8, p<0.0001), epidermal thickness (25.7±12.8 μm, p=0.0045), infiltrated mast cells (31.3±12.4 cells/field, p=0.0475), and Th-type cytokines expression (INF-γ, TNF-α, IL-4, IL-4R, IL-13, and IL-17A; p<0.05) in AD skins. TEWL (29.8±13.8 g/m 2.h, p=0.0306) and skin barrier-related proteins expression (filaggrin: 14258±4375, p=0.0162; loricrin: 6037±1728, p=0.0010; claudin-1: 20043±6406, p=0.0420; ZO-1: 4494±1114, p=0.0134) were also improved. ACF improved AD in murine model by ameliorating inflammatory dysregulation and skin barrier defects (Graphical abstract, Supplementary Digital Content 1). Further validation is needed in more advanced animal models.