Modulation of Gene Expression in a Sterile Atopic Dermatitis Model and Inhibition of Staphylococcus aureus Adhesion by Fucoidan

Abstract

Atopic dermatitis is a multifactorial pathology that includes perturbations of gene expression and increased adhesion of Staphylococcus aureus. Fucoidans are seaweed-derived sulfated fucose-rich polysaccharides that are known to be anti-inflammatory and may inhibit adhesion of pathogens. Fucoidan was assessed for effects on gene expression of an in vitro 3D model of atopic dermatitis. It was also assessed for inhibitory effects on the adhesion of bacteria onto 3D reconstructed skin. Fucoidan significantly altered gene expression in the atopic dermatitis model, and there was a trend to reduce periostin levels. Fucoidan significantly inhibited the adhesion of Staphylococcus aureus and Cutibacterium acnes but did not affect the adhesion of Staphylococcus epidermidis. Fucoidan may be a useful topical agent to assist in the management of atopic dermatitis.

Keywords: Staphylococcus aureus; atopic dermatitis; fucoidan; periostin; reconstructed human epidermis.

Figure 1

Histological sections of Th2-stimulated reconstructed human epidermis (RHE) after 48 h or topical and systemic treatments with the test compounds and reference of its solvent, respectively (H/E staining; n = 1). (a) control; (b) Th2 (+PBS topic); (c) Th2 + DMSO 0.05% (d) Th2 + 10 µM GW3965 in 0.05% DMSO; (e) Th2 + 100 µ/mL FV; (f) Th2 + 100 µ/mL UP.

Figure 2

Volcano plots in analyzing differential gene expressions comparing between (a) control RHE and Th2 induced-RHE, (b) Th2 induced-RHE and FV treated Th2 induced-RHE and (c) Th2 induced-RHE and UP treated Th2 induced-RHE. Fold change boundary: 1 and p-value boundary: 0.05.

Figure 2

Volcano plots in analyzing differential gene expressions comparing between (a) control RHE and Th2 induced-RHE, (b) Th2 induced-RHE and FV treated Th2 induced-RHE and (c) Th2 induced-RHE and UP treated Th2 induced-RHE. Fold change boundary: 1 and p-value boundary: 0.05.

Figure 3

Changes in the periostin (POSTN) abundance in (a) Th2-induced RHE in 0.05% DMSO and in the presence of GW3965 and (b) in the presence of FV and UP. Data are given in percentage relative to the untreated condition. (*** p < 0.001, ** 0.001 < p < 0.01 and ns p > 0.05).

Figure 4

Concentrations of adherent (a) S. epidermidis, (b) S. aureus and (c) C. acnes after topical treatment with FV and UP. The concentrations are expressed in CFU/RHE. The graph represents the means obtained on three independent cultures with three counts for each of them, as well as the standard deviation. The values of 0.001 < p < 0.05 are considered as significant (*). Student’s test compared to control.