Figure 15.

TSG-6 retains HA in the ECM of the epidermis. (a) Schematic representations of in vitro observations in TSG-6^+/+ and TSG-6^–/– RHE challenged or not challenged. In control conditions, weak amounts of HA (green) and TSG-6 (red) are released in the culture medium. In inflammatory conditions, increased TSG-6 secretion goes along with enhanced HA release. In the absence of TSG-6, HA release is significantly increased, especially after the challenge. (b) Hypothetical role of TSG-6 in HA distribution and organization in healthy and lesional atopic dermatitis epidermis. In the healthy epidermis, the weak amount of secreted TSG-6 is involved in ECM organization by HA cross-linking. In atopic dermatitis lesions, enlarged intercellular spaces go along with enhanced HA production. Secreted TSG-6 links HA cables to form a dense matrix. ECM, extracellular matrix; HA, hyaluronan; RHE, reconstructed human epidermis.